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FIELD OF THE INVENTION
The invention relates to a method of removing a weft incorrectly inserted on a jet loom, and a device for carrying out the method.
BACKGROUND OF THE INVENTION
The introduction of electronics into weaving technology has been accompanied, from the very beginning, by efforts aimed at removing the causes of jet loom run interruption. One of these causes is an incorrect weft insertion which is detected by a weft stop motion which then gives a signal to stop the machine run. The chief problem in this operation is how to release the incorrectly inserted but already beaten-up weft, especially with fine staple yards.
There are several known mechanisms for this purpose and they can be classified substantially into three groups, viz., mechanisms for drawing out the weft in its axis without releasing it previously, mechanisms releasing the weft by its transverse displacement with subsequent drawing out in the pick axis, and finally mechanisms producing on the incorrectly inserted weft a wave progressing in the pick axis to release the weft progressively and to draw it out then in the pick axis.
The first of these known mechanisms is relatively simple mechanically but not applicable to fine staple yarn wefts due to a high degree of risk of damaging these wefts. A common drawback of the other two mechanisms is their complexity.
There are also several known devices for automatically removing an incorrectly inserted weft. With one of them, the incorrectly inserted, beaten-up and cut off weft is first released by shaft motion, then gripped by manipulator tongs and drawn towards the main jet so as to be presented to the winding device which finishes the removal of the weft from the shed. Another known device for automatic removal of an incorrectly inserted weft operates on a similar principle using its non-separation, and achieving the presentation of the weft to the take down device by means of a portion of the supply of the metering device fed by an ancillary jet. The drawing-off proper is directed towards the main jet, like in the above mentioned known device.
The drawback of the above-mentioned devices is that for releasing the beaten-up weft from the shed, especially with staple yarns, a considerable force is required, in many cases superior to the strength of the weft to be removed. For this reason, the removal of incorrectly inserted wefts by means of such devices is difficult, sometimes even impossible on fine staple yarns. Besides, the devices themselves are considerably complicated and accordingly costly.
SUMMARY OF THE INVENTION
These drawbacks of the known solutions are eliminated by the method for removing an incorrectly inserted weft according to the present invention. The principle of the method of the present invention includes the incorrectly inserted picking length of the weft being removed in shape of the loop evolving to the shed-end side by a pull exerted on the whole (after the whole) subsequent pick length of the weft.
The principle of the device for carrying out the method according to the invention includes a release mechanism situated on the measuring device, a device for re-tensioning the weft situated between the main jet and the measuring device, ancillary scissors, a plurality of blowing-off jets, each of which is arranged in relation with one of a plurality of relay-like arranged jets, a locking device of main scissors, and a winding-off (drawing-off) device situated on the shed-end side of the jet loom.
Advantages of the device for carrying out the method according to the invention include the ability to remove an incorrectly inserted weft, even of a fine staple yarn, by simple means, without mechanical intrusion into the warp area, in a very non-aggressive manner taking due consideration of fine staple yarn properties.
BRIEF DESCRIPTION OF THE DRAWING
With these and other objects in view, which will become apparent in the following detailed description, the present invention, which is shown by example only, will be clearly understood in connection with the accompanying drawing, in which:
FIGS. 1, 2 and 3 show, schematically, the phases of action of the method according to the invention;
FIG. 4 shows and is a schematic view of an overall arrangement of the device for carrying out the method according to the invention;
FIG. 5 is a perspective view of a possible version of the blowing-off jet positioning; and
FIG. 6 shows a sequence diagram of the method according to the present invention.
FIG. 7 is a perspective view if elements of the invention shown in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The device for performing the method according to the invention (FIG. 4) is intended for cooperation with standard mechanisms of a jet weaving machine (not shown). These mechanisms include: a weft measuring device 1 of any currently used type, mounted on the machine frame; a main jet 4 mounted on the sley, having a mixing chamber 18 and an outlet mouth 19, and controlled by valve 20; main scissors 5 driven by a cam 6 and a riser 7, into which a blocking device, consisting of an air bag 8 and a valve 26, is inserted; successively operated auxillary jets 10 fed with air pressure via valve 23 and mounted on a sley (not shown) adjacent to reed 17, which is fixed to the weaving machine sley (not shown), and provided with a sensor of a weft pick stop motion 13 and a sensor of a mispick stop motion 14.
The inventive device includes a release mechanism 2, which is mounted on the weft measuring device 1. The release mechanism 2 preferably comprises an electromagnetically actuated needle. A weft tensioning device 3 is mounted on the sley. The weft tensioning device is actuated by valve 30, and comprises a mixing chamber 21 and an outlet mouth 22 oriented oppositely relative to mouth 19 of main jet 4, or oriented perpendicularly to the weft between the weft measuring device 1 and the main jet 4.
The inventive device also includes ancillary scissors 9, which are controlled by cylinder 28 and valve 29, and are fixed to the sley between mouth 19 of the main jet 4 and reed 17, blowing down jets (nozzles) 11 fixed to the sley and made as a body with an outlet hole, e.g. a tube connected to the air pressure distribution 32 by valve 21 and placed at the perpendicular lateral (side) wall of the successively operated auxiliary jet 10, a locking device of the main scissors 5 for prevention of the separation of the mispicked weft 16, the locking device being made e.g. as an air bag 8 connected to the air pressure distributor 32 by valve 26, inserted as a transmission member into the drive mechanism 7 of main scissors 5, and a withdrawing mechanism 12 situated on the shed-end side of the weaving machine, made in the form of a suction nozzle consisting of a mixing chamber 24 with an outlet mouth 25, and connected to the air pressure distributor 32 by valve 27.
The device can be controlled by a not represented control center, for instance by a microprocessor.
The sequence of operations to be carried out for removing an incorrectly inserted weft according to the method of this invention may be seen from the sequence diagram (FIG. 6) in connection with FIGS. 1, 2, and 3 showing the phases of the operation.
Upon a signal from the picking stop motion sensor 13 or the mispick stop motion sensor 14, which arrives at approximately 60 degrees of angular displacement of the main shaft before the beat-up, machine stoppage in open shed condition takes place.
Simultaneously, an instruction is sent for not separating the mispicked weft 16, this being performed by discharging air pressure from the air bag 8 through valve 26, which is situated in the driving part of the main scissors 5. In that manner, the lift of the cam 6 is transferred only into the air bag 8. Thus, the main scissors 5 do not perform the motion of the cutting blades and, therefore, the mispicked weft 16 is not separated from the weft supply on the weft measuring device 1.
Simultaneously, an instruction is given for temporary release of the weft supply on the weft measuring device 1, e.g. by lifting the release mechanism 2 for a certain part of the machine revolution. This release is necessary for preventing the breakage of the not separated and woven-in weft during the movement of the main jet 4 into the picking position.
Simultaneously, the instruction for re-tensioning the weft is given by activation of the tensioning device 3, e.g. by feeding air pressure to the nozzle by means of the electromagnetic valve 30. Thereby, by pull in the direction opposite to the picking direction, that weft part is tensioned, which was released upon machine stoppage in the space between the main jet 4 and the beat-up straight line, to prevent that released part of the weft from being woven-in upon reverse run of the machine.
Upon reversing the machine to the preceding shed and releasing the mispicked weft 16, the re-tensioning by the tensioning device is stopped. Moreover, it is possible to cancel the instruction of non-separating weft, by re-feeding air pressure into the air bag 8 by means of electromagnetic valve 26.
In a further step, the blowing down jets (nozzles) 11 are activated by opening valve 31 (FIG. 5), which blow on the vertical side walls of the successively operated auxillary jets 10, thus forming an air cushion, which prevents the weft from being hung up on the successively operated auxiliary jets 10 upon its withdrawal in the form of an evolving loop.
Simultaneously, the withdrawing mechanism 12 is activated by supplying air pressure through valve 27, said withdrawing mechanism being made e.g. in the form of a jet.
Thereafter, the picking of one insertion weft length is performed, which is deposited and measured on the weft measuring device 1, by means of the main jet 4 and the successively operated auxiliary jets 10. The picked weft supply forms a loop 15, because it is at one end connected to the weft on the weft measuring device 1 and at the other end with the mispicked weft situated in the beat-up straight line.
Thereafter, the main jet is set out of operation, loop 15 being thus maintained in tensioned condition by the successively operated auxiliary jets 10 in that part of said loop 15, which is situated in the insertion channel of reed 17. Now, the weft is separated by ancillary scissors 9, which are controlled by pneumatic cylinder 28, to which air pressure is fed by means of electromagnetic valve 29, and the successively operated auxiliary jets 10 bring the released part of loop 15 through the inserting channel of reed 17 to the mouth of the withdrawing device 12.
Then the withdrawing device 12 withdraws the picked and reversed weft and the mispicked weft 16 is connected thereto, in the form of an evolving loop. A signal from the mispick stop motion sensor 14, which at the time the weaving machine is stopped and the unweaving cycle is performed, operates as a supervision of the correctness of the unweaving operation and upon the removal of the weft, the successively operating jets 10, the blowing down nozzles 11 and the withdrawing device 12 are stopped.
Thereafter, the machine is brought into the starting position and restarted.
The device makes possible, in its arrangement, a gentle treatment of the removed weft, and is therefore suitable for performing the method of withdrawing mispicked weft in weaving machines processing particularly fine staple yarns, of which the withdrawal in another manner is difficult, or even impossible.
Referring now to FIG. 6, the steps of the inventive method are illustrated in a flow chart which will be discussed in detail as follows with references to the flow chart shown in parentheses:
During the weaving process (weaving) each inserted weft is sensed by the mispick stop motion 14 and the pick stop motion 13 (FIGS. 4 and 7). When either a positive signal from mispick stop motion 14 is emitted (mispick stop motion signal-yes), or a negative signal from pick stop motion 13 is emitted (pick stop motion signal-no), then the instruction not to separate the mispicked weft 16 (weft separation injunction) follows. In the case of a positive signal from mispick stop motion 14, an indicator (yes-flag) is also set. If the signals of the stop motions 14, 13 are reversed relative to the situation specified above, and weaving process is continued.
Upon the signal for weft separation injunction, air is released from the air bag 8 and, thereupon, the lift of cam 6 reaches only the air bag 8, and is not transferred to the main scissors 5. Then, by lifting the release mechanism 2 on the weft measuring device 3, the weft supply is released for a predetermined interval, i.e. a predetermined part of the machine revolution (weft supply release).
Immediately, the weft is retensioned (weft re-tensioner activation) by activating the weft re-tensioning device 3, during machine stoppage (machine stop) for the purpose of preventing the previously released weft section from being woven in during the reverse stroke of the weaving machine which follows (machine reverse one revolution).
After the reverse stroke and the release of the mispicked weft 16, the retensioning device 3 is set out of operation (weft re-tensioner switching off). Then, the main scissors 5 are unlocked to allow separation of the weft (weft separation permission). Thereafter, the blowing down jets 11 and the drawing-off device 12 are activated (blowing-out nozzles and draw-off device activation). Then, the main jet 4 and the relay-like auxiliary jets 10 are activated for picking the weft from the weft measuring device in the form of loop 15 into the drawing-off device 12 (main nozzle and relay nozzles activation). The main jet 4 is then set out of operation (main nozzle switching off), the weft is separated by the ancillary scissors 9 (weft separation by auxiliary cutter) and drawn off by the drawing-off device 12 in tensioned condition in the form of loop 15, maintained by means of relay-like jets 10.
Upon finishing the withdrawal of weft 16 by the drawing-off device 12, this is indicated by the mispick stop motion 14 (mispick stop motion signal-yes, in the right hand column of FIG. 6), and by this indication, the relay-like jets 10 are set out of operation (relay nozzles switching off), the blowing down jets 11 and the drawing-off device 12 are also set out of operation (blowing-out nozzles and draw-off device switching off).
Thereupon, by a signal from the mispick stop motion 14 (mispick stop motion signal in the middle of the right column of FIG. 6), the machine is either stopped (machine stop) or, depending on the flag contents (flag contents), the weaving machine is adjusted into its starting position (machine starting position adjustment) and then started (machine start) and the weaving process is continued.
Although the invention is described and illustrated with reference to a preferred embodiment thereof, it is to be expressly understood that it is in no way limited to the disclosure of such preferred embodiment but is capable of numerous modifications within the scope of the appended claims.
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A device for removing an incorrectly inserted weft on a jet loom includes nozzles, a scissor locking device, and a suction device operated in response to signals from sensors sensing the position of the weft. The incorrectly inserted weft picking length is removed in the shape of an evolving loop in the direction towards the shed end side by a pull exerted on the whole subsequent picking length of the weft.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of co-pending of U.S. patent application Ser. No. 11/061,799, filed Feb. 18, 2005, which claims priority to French Patent Application Serial Number 04 03434, filed Apr. 1, 2004, all of which are hereby incorporated by reference as if set forth herein.
BACKGROUND OF THE INVENTION
The invention relates generally to managing voltage differences between shrinking transistor technology and non-volatile memory read/write requirements. Specifically, the invention relates to power supply management for embedded non-volatile memory such as electrically erasable programmable read-only memory (EEPROM) and FLASH memory.
DESCRIPTION OF THE RELATED ART
In order to maintain acceptable power consumption and reliability with advanced technology, supply voltage has been reduced from 5V with 1 μm technology down to 1.8V with 0.18 μm technology. However, supply voltage has not decreased at the system level. Most systems on chips (SOCs) using a 0.18 μm technology are 3.3V compliant, and 5V compliant or tolerant.
FIG. 1 is a schematic illustrating a prior art power supply management system for a memory. SOC 5 illustrates one example of how power is distributed. External voltage level 10 , for example 3.3V or 5V, is applied to voltage regulator 15 , analog circuit 20 , and input/output pads 25 . Voltage regulator 15 generates regulated voltage level 30 , for example 1.8V for a 0.18 μm logic. Regulated voltage level 30 is applied to memory 40 , for example embedded EEPROM and FLASH memory, and advanced logic 35 , for example the micro-controller, CMOS memories, glue logic etc.
When memory 40 is supplied with regulated voltage level 30 , advanced CMOS logic may be used in memory 40 , resulting in improved density and speed. However, using regulated voltage level 30 during memory write and read for memory 40 results in several issues. Memory write and read use higher voltages than supplied by regulated voltage level 30 , and the higher voltages are typically reached by larger charge pumps. Because the memory cell current during memory read depends on the word line voltage, boosting the word line above regulated voltage level 30 during read is commonly used to provide better functionality. However, boosting is time and current consuming.
FIG. 2 is a schematic illustrating another prior art power supply management system for a memory. SOC 200 illustrates one example of how power is distributed. External voltage level 210 is applied to voltage regulator 215 , analog circuit 220 , and input/output pads 225 . Voltage regulator 215 generates regulated voltage level 230 . Regulated voltage level 230 is applied to advanced logic 235 , for example the micro-controller, CMOS memories, glue logic etc.
When memory 240 is supplied with external voltage level 210 , charge pump size may be reduced, and boosting during read is typically not performed. However, the logic parts of memory 240 typically use thick oxide devices, because thin oxide devices do not operate at external voltage level 210 . Control logic, pre-decoding and output data-path are larger and slower compared to the lower voltage embodiment illustrated in FIG. 1 . Furthermore, level shifter 245 interfaces with the inputs and outputs of memory 240 , to allow communication with advanced logic 235 , which is supplied with regulated voltage level 230 .
What is needed is a power management system for memory that allows the use of advanced CMOS logic in memory, resulting in improved density and speed, while also reducing charge pump size, and reducing the need for boosting during read. The invention should reduce the area required by memory, improve speed, reduce power consumption, use available power supply resources, and be scalable.
SUMMARY OF THE INVENTION
The invention consists of a dual power supply memory management system that provides an external voltage level to memory as well as the internally generated voltage level. The low voltage, logic parts of the memory may use thin oxide devices and are supplied by the regulated voltage level, while the external voltage level is directly supplied to the charge pump for memory write, and to the word line and bit line decoding during memory read. The invention allows for high-speed devices for decoding and sensing, while avoiding internal boosting delays during memory read, and avoiding over-sizing of the write charge pump.
The invention is an embedded non-volatile memory being driven at an external voltage level and at a regulated voltage level. The external voltage level is higher than the regulated voltage level. The invention comprises the following. A charge pump is configured to receive the external voltage level and generate a high voltage level, wherein the high voltage level is higher than the external voltage level. A memory control circuit is coupled to the charge pump and is configured to receive the external voltage level and the high voltage level. The memory control circuit is further configured to select between and provide the external and the high voltage levels. A memory array, which has a word line and a bit line, is coupled to the memory control circuit. The memory array is configured to store data, to receive the external and high voltage levels at the word line, and to receive the high voltage levels at the bit line. A word line driver is coupled to the memory array and is configured to provide the external and high voltage levels to the word line. A bit line selector is coupled to the memory array and is configured to select the bit line and receive the high, external, and regulated voltage levels. A bit line driver is coupled to the bit line selector and is configured to provide the external and regulated voltage levels to the bit line selector.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustrating a prior art power supply management system for a memory.
FIG. 2 is a schematic illustrating a prior art power supply management system for a memory.
FIG. 3 is a schematic illustrating one embodiment of a power supply management system for memory in a system-on-a-chip (SOC).
FIG. 4 is a schematic diagram illustrating one embodiment of the memory from FIG. 3 .
FIG. 5 is a schematic illustrating one embodiment of a memory control circuit.
FIG. 6 is a schematic illustrating one embodiment of a word line driver.
FIG. 7 is a schematic illustrating one embodiment of a bit line selector.
FIG. 8 is a schematic illustrating one embodiment of a bit line driver.
FIG. 9 is a flow diagram illustrating a method of driving an embedded non-volatile memory.
FIG. 10 is a schematic diagram illustrating one embodiment of a memory control circuit.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 3 is a schematic illustrating one embodiment of a power supply management system for memory in a system-on-a-chip (SOC). SOC 300 illustrates one example of how power is distributed. External voltage level 310 , for example 3.3V or 5V, is applied to voltage regulator 315 , analog circuit 320 , and input/output pads 325 . Voltage regulator 315 generates regulated voltage level 330 , for example 1.8V for a 0.18 μm logic. Regulated voltage level 330 is applied to memory 340 , for example embedded EEPROM and FLASH memory, and advanced logic 335 , for example the micro-controller, CMOS memories, glue logic etc. External voltage level 310 is also applied to memory 340 .
FIG. 4 is a schematic diagram illustrating one embodiment of memory 340 from FIG. 3 . Memory 400 receives external voltage level 405 and regulated voltage level 410 (from voltage regulator 315 of FIG. 3 ). Charge pump 407 receives external voltage level 405 and generates high voltage level 415 , which is used to program memory cells during memory write. Because charge pump 407 is supplied with the higher, external voltage level 405 , charge pump 407 may be smaller than a conventional memory charge pump supplied by regulated supply voltage 410 .
Memory control circuit 420 receives high voltage level 415 from charge pump 407 and external voltage level 420 . Memory control circuit 420 supplies either high voltage level 415 or external voltage level 420 to variable voltage line 425 . During a memory read, memory control circuit 420 supplies external voltage level 420 to variable voltage line 425 . During a memory write, memory control circuit 420 supplies high voltage level 415 to variable voltage line 425 .
Memory 400 includes memory array 430 with memory cells, word lines and bit lines (not shown). X pre-decoder 435 receives and decodes an address and is powered at regulated voltage level 410 . X pre-decoder 435 is connected to word line driver 440 with a word select input line (see FIG. 6 ). Word line driver 440 receives power from variable voltage line 425 and receives a word select that indicates a word line to supply with power. During memory read, word line driver 440 supplies the word line with external voltage level 405 . During memory write, word line driver 440 supplies the word line with high voltage level 415 .
Y pre-decoder 445 receives and decodes an address and is powered at regulated voltage level 410 . Y pre-decoder 445 is connected to select driver 450 . Select driver 450 receives external voltage level 405 and a bit select signal from Y pre-decoder 445 , which is shifted to external voltage level 405 due to the level shifter.
Bit line selector 455 is connected to select driver 450 and receives a dual powered signal from select driver 450 , at regulated voltage level 410 and external voltage level 405 . Bit line selector 455 selects bit lines in memory array 430 for memory read.
Sense amplifier 460 with a data output is connected to bit line select 455 . Sense amplifier 460 receives regulated voltage level 410 .
Column latch 465 connects to memory array 430 and stores data that will be programmed in parallel to memory array 430 and drives the cells corresponding to bit lines that are being written to.
Control logic 470 operates at regulated voltage level 410 and manages functional modes, test modes, and writing delays in memory 400 .
FIG. 5 is a schematic illustrating one embodiment of memory control circuit 500 . Variable voltage line 505 receives high voltage level 415 from charge pump 407 (see FIG. 4 ). Transistor 510 is, for example, a PMOS transistor with a drain connected to variable voltage line 505 and a source connected to external voltage level 405 . The gate of transistor 510 connects to the source of transistor 515 and the drain of transistor 520 . The drain of transistor 515 is connected to variable voltage line 505 . The source of transistor 520 is connected to ground. The gates of both transistors 515 and 520 are connected together and to level shifter 525 . Level shifter 525 is connected to variable voltage line 505 , inverter 530 , and read signal line 535 .
In one embodiment, level shifter 525 receives a read signal indicating memory read from read signal line 535 . Level shifter 525 sends a high output to node 540 . A high output to the gate of transistor 520 turns it on (asserts it) while a high output to the gate of transistor 515 turns it off (deasserts it). Transistor 520 pulls node 545 to ground, therefore turning on, or asserting transistor 510 . Variable voltage line 505 , which is now connected to external voltage level 405 through active transistor 510 , is at external voltage level 405 .
During memory write, level shifter 525 receives a read signal indicating memory write from read signal line 535 . Level shifter 525 sends a low output to node 540 . A low output to the gate of transistor 520 turns it off (deasserts it) while a low output to the gate of transistor 515 turns it on (asserts it). Transistor 515 pulls node 545 to high voltage level 415 , therefore turning transistor 510 off. Variable voltage line 505 , which is now isolated from external voltage level 405 through inactive transistor 510 , is at high voltage level 415 .
One embodiment of level shifter 525 is illustrated in FIG. 5 . Transistor 550 is, for example, a PMOS transistor with a drain connected to variable voltage line 505 . Transistor 555 is, for example, a PMOS transistor with a drain connected to variable voltage line 505 and a gate connected to the source of transistor 550 and a source connected to the gate of transistor 550 . Transistor 560 is, for example, a NMOS transistor with a drain connected to the gate of transistor 555 , the source of transistor 550 , and node 540 , a source connected to ground, and a gate connected to inverter 530 . Transistor 565 is, for example, a NMOS transistor with a drain connected to the source of transistor 555 and the gate of transistor 550 , a source connected to ground and a gate connected to read signal line 535 .
Level shifter 525 receives a read signal indicating memory read, in this case node 535 is set to regulated voltage level 410 . The signal is inverted by inverter 530 , therefore turning off transistor 560 and turning on transistor 565 . The gate of transistor 550 is pulled low, therefore turning it on. The gate of transistor 555 is pulled high, therefore turning it off. Node 540 is pulled high by transistor 550 , which is on.
Level shifter 525 receives a read signal indicating memory write, in this case node 535 that is set to ground level. The signal is inverted by inverter 530 , therefore turning on transistor 560 and turning off transistor 565 . The gate of transistor 550 is pulled high, therefore turning it on. The gate of transistor 555 is pulled low, therefore turning it off. Node 540 is pulled low by transistor 560 , which is on.
When beginning memory write, if an undershoot of the potential at node 505 occurs, then the bulk potential at transistor 510 may switch below its source potential, which is directly connected to external voltage level 405 . This may result in a substrate parasitic current disturbing the correct functionality of the charge pump.
In order to resolve the issue of the substrate current, transistor 511 has been added, as illustrated in FIG. 10 . FIG. 10 is a schematic diagram illustrating one embodiment of memory control circuit 500 . Transistor 511 is, for example, a PMOS transistor with its drain connected to the source of transistor 510 , its source and bulk connected to external voltage level 405 , and its gate connected to the output of level shifter 526 . During memory write, node 535 is set to ground, the input of level shifter 526 is set to regulated voltage level 410 and the output of level shifter 526 is external voltage level 405 , which turns off transistor 511 . The source of transistor 510 , which is connected to node 547 , is now floating, avoiding substrate parasitic current even during undershoot of its drain.
During a memory read, node 535 is set to regulated voltage level 410 . The input and output of level shifter 526 is ground, which turns on transistor 511 and drives node 547 to external voltage level 405 . Because transistor 510 is also on, variable voltage line 505 is connected to external voltage level 405 through transistors 510 and 511 .
FIG. 6 is a schematic illustrating one embodiment of word line driver 440 . Word line driver 440 is connected to X pre-decoder 435 directly and through inverter 501 . X pre-decoder 435 receives regulated voltage level 410 and memory address locations. Inverter 601 provides an inverted output of its input. Word line driver receives an inverted and normal signal from X pre-decoder 435 and a control signal indicating a memory read.
Word line driver 600 is one embodiment of word line driver 440 . Transistor 605 is, for example, a PMOS transistor with a drain connected to variable voltage line 610 , a source connected to word line 615 . Transistor 620 is, for example, a NMOS transistor with a drain connected to the output of X pre-decoder 435 , a source connected to word line 615 , and a gate receiving a control signal. Level shifter 625 is connected to variable voltage line 610 and receives the output of inverter 601 and the output of X pre-decoder 435 . Level shifter 625 has an output connected to the gate of transistor 605 .
If word line 615 is selected by X pre-decoder 435 , then input 630 is high and input 635 is low. In this example, high is at regulated voltage level 410 while low is at ground. Level shifter 625 pulls the gate of transistor 605 to ground, therefore turning it on and connecting variable voltage line 610 to word line 615 . Given that word line 615 is selected, either memory read or memory write is occurring.
During memory write, memory control circuit 420 provides high voltage level 415 on variable voltage line 610 . Transistor 620 receives a control signal at its gate and turns off because memory write is occurring and word line 615 is connected to high voltage level 415 .
During memory read, memory control circuit 420 provides external voltage level 405 on variable voltage line 610 . Transistor 620 receives a control signal at its gate and turns on because memory read is occurring. Transistor 620 is a low threshold voltage transistor that decreases the word line rising delay during memory read. Transistors 620 and 605 charge word line to regulated voltage level 410 minus the threshold voltage of transistor 620 . Once word line 615 reaches regulated voltage level 410 minus the threshold voltage of transistor 620 , transistor 620 turns off and the remaining charge to bring word line to external voltage level 405 is supplied by transistor 605 .
One embodiment of level shifter 625 is illustrated in FIG. 6 . Transistor 650 is, for example, a PMOS transistor with a drain connected to variable voltage line 610 . Transistor 655 is, for example, a PMOS transistor with a drain connected to variable voltage line 610 and a gate connected to the source of transistor 650 and a source connected to the gate of transistor 650 . Transistor 660 is, for example, a NMOS transistor with a drain connected to the gate of transistor 655 , the source of transistor 650 , and node 640 , a source connected to ground, and a gate connected to X pre-decoder 435 . Transistor 665 is, for example, a NMOS transistor with a drain connected to the source of transistor 655 and the gate of transistor 650 , a source connected to ground and a gate connected to inverter 601 .
Level shifter 625 receives a signal selecting word line 615 , in this case regulated voltage level 410 . The signal is inverted by inverter 601 , therefore turning off transistor 665 and turning on transistor 660 . The gate of transistor 655 is pulled low, therefore turning it on. The gate of transistor 650 is pulled high, therefore turning it off. Node 640 is pulled low by transistor 655 , which is on, therefore turning on transistor 605 .
Level shifter 625 receives a signal deselecting word line 615 , in this case the gate of transistor 660 is connected to ground, and the gate of transistor 665 is connected to regulated voltage level 410 , therefore turning on transistor 665 and turning off transistor 660 . The gate of transistor 655 is pulled high, therefore turning it on. The gate of transistor 650 is pulled low, therefore turning it off. Node 640 is pulled high by transistor 560 , which is on, therefore turning off transistor 605 .
One example of a prior art 2 megabit EEPROM in 0.18 μm technology, with 1.8V single supply operation, takes 11 ns to charge the word line to 2V and 20 ns to charge the word line to 2.5V. The invention provides a charge time for the word line of 5 ns and 9 ns, respectively.
FIG. 7 is a schematic illustrating one embodiment of bit line selector 455 . Bit line selector 700 includes transistors 710 , which in one embodiment are NMOS, thick oxide, large effective length, poor gain devices. During memory write, transistors 710 are connected to high voltage level 415 . Transistors 710 have a drain connected to memory cells (not shown) in memory array 430 (see FIG. 4 ). Each of transistors 710 has a source connected to the drain of transistor 720 . In one embodiment, transistor 720 is a thin oxide, high drive device with a source connected to sense amplifier 460 . Transistor 720 is not connected to high voltage level 415 .
In order to charge the bit line quickly during read, transistors 710 should operate quickly. One method of speeding operation time of transistors 710 is by increasing their width. Another solution is to drive the gates of transistors 710 to external voltage level 405 . When a bit line is selected, the gate of one of transistors 710 will be driven to external voltage level 405 in order to decrease bit line charge time. The gate of transistor 720 will be driven to regulated voltage level 410 . Bit line driver 450 drives transistors 710 and 720 .
FIG. 8 is a schematic illustrating one embodiment of bit line driver 450 . Bit line driver 800 receives a signal from Y pre-decoder 810 at regulated voltage level 410 indicating which one of transistors 710 should be selected. In one embodiment, bit level driver 800 is a level shifter that receives external voltage level 405 and applies external voltage level 405 to the gate of selected transistor 710 .
Y pre-decoder 810 receives and decodes an address indicating which of transistors 710 to select and selecting transistor 720 by applying regulated voltage level 410 to the gate of transistor 720 .
One example of a prior art 2 megabit EEPROM in 0.18 μm technology, with 1.8V single supply operation, takes 40 ns for memory access time. The invention provides an access time of 25 ns.
FIG. 9 is a flow diagram illustrating a method of driving an embedded non-volatile memory, having a word line and a bit line, at an external voltage level and at a regulated voltage level, the external voltage level higher than the regulated voltage level lower. In block 900 , boost the external voltage level to a high voltage level, the high voltage level higher than the external voltage level. In block 910 , supply the high voltage level to a variable voltage line during memory write. In block 920 , supply the external voltage level to the variable voltage line during memory read. In block 930 , switch the high voltage level from the variable voltage line to the word line during memory write. In block 940 , precharge the word line with the regulated voltage level during memory read. In block 950 , switch the external voltage level from the variable voltage line to the word line during memory read. In block 960 , turn on a transistor in the bit line select with the external voltage level. In block 970 , turn on a transistor in the bit line select with the regulated voltage level.
The advantages of the invention include a reduced chip area achieved by reducing the size of the charge pump and bit line select, improved speed, reduced power consumption (boost pump during read is not required), and use of available power supply resources. The invention may apply to embedded FLASH and is scalable. The invention may be applied in embedded applications where thin oxide, low voltage devices requiring a dedicated regulated low voltage are needed for advanced digital logic, while thick oxide devices may be used for a variety of memory. With deep, submicron technologies, this concept applies to SRAM and DRAM memory, where thick oxide, high threshold voltage devices may be used in the array in order to prevent leakage current, for example. The invention may be applied in stand-alone memory as well, in order to optimize speed and decrease control logic area.
One of ordinary skill in the art will recognize that configurations of different circuit components may be used without straying from the invention. The illustrated embodiments of the invention include, for example P and N transistors, and invertors, but one skilled in the art recognizes that these may be interchanged and/or replaced by components with similar functionality, applying appropriate circuit rerouting. As any person skilled in the art will recognize from the previous description and from the figures and claims that modifications and changes can be made to the invention without departing from the scope of the invention defined in the following claims.
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A charge pump is configured to receive an external voltage level and generate a high voltage level, wherein the high voltage level is higher than the external voltage level. A memory control circuit is configured to receive the external voltage level and the high voltage level, and to select one of the voltage levels. A memory array, with a word line and a bit line, is configured to receive the external and high voltage levels at the word line and the high voltage levels at the bit line. A word line driver is configured to provide the external and high voltage levels to the word line. A bit line selector is configured to select the bit line and receive the high, external, and regulated voltage levels. A bit line driver is configured to provide the external voltage levels to the bit line selector.
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FIELD OF INVENTION
This invention relates to power control in radio communications systems such as CDMA cellular telephone systems.
BACKGROUND OF INVENTION
‘Outer loop’ power control is required in a CDMA system to set an appropriate target for the ‘inner loop’ power control loop which is just high enough to achieve the desired quality of service (QoS). This target point value will vary as a function of channel propagation (e.g., dispersiveness or user speed). Without effective power control, users perceived QoS will be severely degraded or network capacity will degrade (as a result of excess power transmission when exceeding desired QoS).
In particular, dynamic outer-loop power control is required in a CDMA system in order to adjust the Eb/No (the ratio of energy per bit to noise power spectral density) target point for an inner power control loop in order to track changes in channel propagation in an attempt to maintain constant QoS.
Future generations of cellular telephone services such as the proposed Universal Mobile Telephone System (UMTS) will offer a plethora of different services, each with quite different QoS requirements in terms of delay, bit error rate (BER) and frame erasure rate (FER). This represents a challenge to mobile radio equipment manufacturers who must therefore design their products to be fully adaptable to these various requirements.
Traditional methods for performing outer-loop power control, such as those based on the ‘sawtooth’ algorithm employed in existing CDMA networks (e.g., the IS-95 cellular standard), are not appropriate for all service types. This is especially true of low FER or high delay services (e.g., video)—which are to be deployed in next generation networks across the world.
SUMMARY OF INVENTION
In accordance with a first aspect of the present invention there is provided an apparatus as claimed in claim 1.
In accordance with a second aspect of the present invention there is provided a method as claimed in claim 6.
BRIEF DESCRIPTION OF DRAWINGS
One embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 shows in block diagrammatic form a system incorporating inner- and dynamic outer-loop power control as known in the prior art;
FIG. 2 shows in block diagrammatic form a scheme for re-encoded channel error rate measurement as employed in the preferred embodiment of the present invention;
FIG. 3 shows in block diagrammatic form a system in accordance with a preferred embodiment of the present invention incorporating a dual outer loop power control scheme (DOLAP);
FIG. 4 shows a graph used in deriving an appropriate value for a counter parameter of the system of FIG. 3; and
FIG. 5 shows a block schematic diagram of a target channel error rate (ChER Target ) update scheme employed in the system of FIG. 3 .
DESCRIPTION OF PREFERRED EMBODIMENT
Two-loop (inner-loop and outer-loop) power control is known in CDMA cellular telephone systems. Dynamic outer-loop power control is required in a CDMA system in order to adjust the Eb/No target point for the inner power control loop in order to track changes in channel propagation (e.g., dispersiveness/user speed). Without effective dynamic outer-loop power control, users perceived QoS will be severely degraded or network capacity will degrade (as a result of excess power transmission leading to excessive QoS).
A diagram depicting inner- and dynamic outer-loop power control is shown in FIG. 1 . In this arrangement, the transmit power 2 of a transmitter 4 is controlled via an inner loop 6 contained within a receiver unit R. The inner loop 6 includes inputs from the transmitted power, a shadow (slow) fading profile 8 , a fast-fading profile 12 , and noise interference 14 . The fast-fading profile 12 is itself dependent on the channel variation (e.g., speed/dispersion) 10 . For the inner loop 6 , receiver circuitry 16 produces from the signal received at the receiver R a power control metric estimate (PCM Est )—a function of received Eb/No—which is used to modulate the transmit power 2 of the transmitter 4 . Additionally, an outer loop 18 is also used to control the transmit power 2 of the transmitter 4 . In the outer loop 18 a quality of service estimate (QoS Est ) is derived from the signal received at the receiver R and is used to produce an outer loop threshold (OLT) signal. The PCM estimate signal PCM Est from the inner loop 6 and the OLT signal from the outer loop 18 are compared and the result is used to control the transmit power 2 of the transmitter 4 .
Future generations of cellular telephone services such as the proposed Universal Mobile Telephone System (UMTS) will offer a plethora of different services, each with quite different QoS requirements in terms of delay, bit error rate (BER) and frame erasure rate (FER). This represents a challenge to mobile radio equipment manufacturers who must therefore design their products to be fully adaptable to these various requirements.
Traditional methods for performing outer-loop power control, e.g., the outer power control loop scheme (based on the ‘sawtooth’ algorithm) commonly deployed in IS-95 CDMA networks, are not appropriate for all service types. This is especially true of low FER or high delay services (e.g., video) which are to be deployed in next generation networks across the world.
The ‘sawtooth’ algorithm can be described as follows: QoS information in the form of frame cyclic redundancy check (CRC) pass/fail is available from the receiver. The frame quality indicator flag q k is set to +1 in the event that the k th received frame was bad, and is set to −1 in the event that the k th received frame was good. A function ƒ(q k ) returns the outer loop step increment based on the QoS input information q k where:
ƒ( q k )=−Δ for q k =−1 and ƒ( q k )=+ K Δ for q k =+1 (1)
That is, for every good frame received the OLT is decreased by an amount Δ, whereas for every bad frame received the OLT is increased by an amount KΔ. Using the given notation the algorithm can be expressed in a more mathematical form as: OLT ( k + 1 ) = OLT ( k ) + 1 2 { ( q k + 1 ) K Δ + ( q k - 1 ) Δ } ( 2 )
A value of K can be derived as a function of the desired FER: K = 1 - 2 FER Target + 1 1 + 2 Fer Target - 1 = 1 FER Target - 1 ( 3 )
Therefore, suppose for example an FER of 1% is desired, then for every good frame received the algorithm decreases the OLT by an amount Δ, whilst for every bad frame received the OLT is increased by 99Δ. This results in the desired FER being attained.
An unwanted transmission power overhead, that is a function of KΔ, is required by the sawtooth algorithm in order for it to attain the desired FER Target . Thus, it will be understood that the excess power transmitted due to the dynamic outer-loop increases with K=1/FER Target and this is where one of the problems with low FER UMTS services becomes apparent. Long constraint delay (LCD) data services have been designed within the UMTS framework to provide QoS's which are equivalent to service frame erasure rates (SFER's) of around 10 −3 . Thus, as there is a lower limit restriction on Δ for channel tracking purposes, the step-up size KΔ becomes very large and much excess power must be transmitted in order to meet QoS. This would significantly reduce network capacity, especially when considering the fact that each high data rate LCD user consumes much more of the power resource within a cell than each low data rate (e.g., speech) user.
The problem here can be summarised in a more generic form. The outer loop exists to track the channel variations in speed and dispersion which may be occurring over a time (e.g., 0.5-5 seconds). As an example, a vehicular user may transition from 120 kmph to close to 0 kmph in less than 5 seconds, where the change in Eb/No at QoS will perhaps be of the order of 2 dB's. The ‘sawtooth’ outer-loop algorithm is driven solely by CRC fail information which, by definition, only occurs very infrequently (e.g., SFER=10 −3 ). Considering a typical UMTS LCD circuit-switched data service with service frame duration of 80 ms, this gives rise to one service frame erasure approximately every 1.5 minutes for SFER≈10 −3 ! Therefore, for any reasonable step-up (KΔ) size, the outer loop will be unable to track the channel variations adequately since the corresponding step-down size (Δ) will have to be set to a very small value. In practical terms the ‘sawtooth’ algorithm is therefore only applicable to low delay services with service frame erasure rates of 10 −2 or higher, or for non-real-time (NRT) services employing automatic repeat request (ARQ). For real-time (RT) services with QoS requirements for low error probability another approach is required.
Thus it will be understood that a different approach is required for LCD services that have a potentially long service frame duration and/or very low SFER QoS targets. In these services the influx of quality information into the outer-loop mechanism is inherently of too low a frequency to adequately track any channel variations without resorting to transmitting large amounts of excess power. For any practical value of Δ the excess power transmission required by the ‘sawtooth’ algorithm will be very high due to the large value that must be assumed by K. Therefore, a more frequent measure of link quality is required to track the channel.
This invention is based on the realisation that the channel bit error rate (e.g., after ‘RAKE’ maximum ratio combining (MRC), but before channel-decoding) corresponding to a particular post channel-decoding QoS is relatively independent of the channel type and speed (it will be understood that RAKE MRC is a technique well known in CDMA systems). That is to say, for any particular QoS, there exists a corresponding channel error rate (ChER) that is by-and-large insensitive to variations in the channel type and speed. Thus, if the ChER at the desired QoS could be found, it would provide a continuous measure to track channel variations in the absence of any other information. However, it may not be desirable to have to set a specific desired ChER for each service and data rate and some automated ChER-target-setting process may be required.
Referring now to FIG. 2, an accurate estimate of the ChER can be obtained from the receiver by comparing a re-encoded version of the decoded information bits with a hard decision on the soft channel bits emanating from the receiver/demodulator. In the scheme of FIG. 2, a receiver/demodulator 20 supplies output to a channel decoder 22 which produces at its output presumed information bits. The channel decoder output is applied to a channel encoder 24 which produces at its output a re-encoded version of the presumed information bits. The output of the channel encoder 24 is compared to the output from the receiver/demodulator 20 and applied to an integrator 26 . The output from the integrator 26 is sampled and reset via a switch 28 at the end of each desired measurement period to produce at its output a re-encoded channel error metric (ReEnc_ChER) commensurate with the received signal portion contained within the measurement period.
It will be appreciated that for certain coding schemes (e.g., recursive) it may be desirable for the re-encoded input to the comparator to be derived other than directly from the decoded bits. A suitable alternative re-encoded metric could be obtained, for example, by concatenating the codewords corresponding to the most likely path through a decoder trellis. At the QoS point, the ReEnc_ChER will be closely, representative of the real channel error rate ChER (since, by definition, the decoded output contains very few errors). In addition, ChER's of between 10% and 20% are typical for turbo-coded LCD services at BER's of 10 −6 and so the effects of the infrequent errors in the decoded bits on the re-encoded metric are very-small.
Referring now also to FIG. 3, based upon the above principle, an outer loop algorithm has been developed that has two constituent loops and for convenience will subsequently be termed the ‘dual-loop algorithm’ or the ‘ D ual O uter- L oop A lgorithm for P ower-control’ (DOLAP). As shown in FIG. 3, a received signal is applied to the information bit recovery arrangement of FIG. 2 to produce a re-encoded channel error rate metric (ReEnc_ChER) and a cyclic redundancy check (CRC) pass/fail signal (CRC p/f ) which is applied to an ‘outer-loop 1 ’ ( 36 ). The ReEnc_ChER signal is applied to an ‘outer-loop 2 ’ ( 40 ) where it is filtered and compared to a target channel error rate signal (ChER Target ) from the ‘outer-loop 1 ’ ( 36 ) to drive a ‘small gain step’ incrementer/decrementer 42 . The ‘outer-loop 1 ’ ( 36 ) also produces an output which drives a ‘big gain step’ incrementer/decrementer 38 . The outputs from the ‘small gain step’ incrementer/decrementer 42 and the ‘big gain step’ incrementer/decrementer 38 are combined to produce a OLT increment/decrement signal (OLT +/− ) which is used to derive the inner power control loop threshold signal OLT.
Thus, the ‘outer-loop 1 ’ ( 36 ) monitors QoS information in the form of CRC pass/fail events. In response to the CRC p/f input, ‘outer-loop 1 ’ ( 36 ) then sets a target channel error rate (ChER Target ) for the ‘outer-loop 2 ’ ( 40 ), and also outputs relatively large OLT increment/decrement adjustments (Δ big ). In the absence of further ‘outer-loop 1 ’ OLT adjustment events, outer-loop 2 then attempts to maintain the specified ChER Target by comparing a filtered version of ReEnc_ChER to ChER Target and adjusting the OLT for the inner PC loop in smaller steps (Δ small ) up or down. Δ big and Δ small may represent multiplicative adjustments to the OLT in the linear domain, or additions in the logarithmic domain (in a similar manner as described for the ‘sawtooth’ algorithm).
It may be beneficial to take an average of the re-encoded channel error rate metric (ReEnc_ChER) over a longer period in order to reduce its variance before it is used by outer-loop 2 . This filtering time duration is irrespective of the service frame duration and data rate.
Considering the outer-loop 1 in more detailed description), the outer-loop 1 performs two functions:
(i) Monitoring Service Frame Quality-of-Service Indicator (SFQI) information and adjusting the OLT by steps +/−Δ big accordingly; and
(ii) Determining ChER Target for outer-loop 2 .
Considering firstly the outer-loop 1 function of monitoring SFQI information and adjusting the OLT, the algorithm for this process is as follows. SFQI n indicates whether the n th service frame was found in error. A value of +1 indicates an error whereas a value of −1 indicates a good service frame. On encountering a SFQI indicating a CRC fail, the process checks to see whether a service frame in the last T service frames has also been found in error. If so, the OLT is adjusted by an amount +Δ big . Upon a CRC fail, a counter is reset. In the absence of further errors this counter increments every subsequent service frame until it exceeds the value T. When this happens, T service frames have been received error-free, and the OLT is adjusted by an amount −Δ big . The counter is again reset upon this event.
The algorithm can be expressed algebraically as: [ OLT ( n ) ] = [ OLT ( n - 1 ) ] * Δ big 2 ( SFQI n + T - counter ( T - counter ) 2 ) ( 4 )
The step size value for Δ big should be large enough to give an appropriate increment upon an undesired service frame erasure event, but must also be small enough so as to prevent much excess transmission of power above the QoS operating point. A typical value for Δ big may be 0.25 dB. Although recommendations for step sizes are given in this example, optimisation of both Δ big and Δ small could be performed.
The value of T that results in the desired SFER has been found via modelling this outer-loop 1 process as a discrete 3-state Markov process. This modelling produces the graph of FIG. 4, which shows (T*SFER) vs. (P err(tot) /SFER). From this graph it can be seen that in order to achieve the desired SFER Target the counter-related parameter T (in equation (4)) must be selected to be: T = 1 SFER Target × 0.66 ( 5 )
Considering now the second function of outer-loop 1 of determining ChER Target for outer-loop 2 , it is to be noted that the above-discussed algorithm for the first outer-loop 1 function (monitoring SFQI information and adjusting the OLT) has a ‘do nothing’ state when neither a big step up nor a big step down event has occurred. In these periods, outer-loop 2 will attempt to maintain a constant channel error rate by adjusting the OLT in small steps up or down in response to a comparison of channel error rate estimate with the channel error rate target. ChER Target is set subsequent to a counter reset in the first function (i.e., when a big step up or down has been made). Referring now also to FIG. 5, the following ChER Target update process occurs. When a counter reset in the first function occurs (i.e., when a big step up or down has been made), this condition is detected, and a wait period 50 (equal to the delay of the re-encoded channel error rate filter 52 ) is entered, during which ReEnc_ChER is sampled and averaged (which is occurring anyway for outer-loop 2 ). After this delay period, the output of the ReEnc_ChER averaging filter 52 is input into a ChER Target filter 54 that is clocked following every counter reset in the first function. The output of this filter is the actual ChER Target to be used by outer-loop 2 .
Thus, the combined operation of outer-loop 1 and outer-loop 2 can be summarised as follows. When the first function of outer-loop 1 decides that a relatively large step change in the OLT is required, it is implemented and the new channel error rate is measured. Once filtered using previous such measurements, this is then assumed to be a new acceptable channel error rate target for outer-loop 2 to track. In this way, the outer power control loop is able to adaptively determine the average channel error rate at the desired QoS point for that service (these can be very different for different services). Any variations in the channel can then be tracked quickly by outer-loop 2 without the need for further CRC event information (which by definition arrives at a very slow rate).
It will be understood that the various filter parameters may need to vary for different service frame durations and different values of SFER Target since these affect the average rate and variance of input information into the ChER Target filter.
An initial channel error rate target must be set at the start of a call. The target will be updated following a counter reset in the first function of outer-loop 1 . It is desirable to set this initial target to a high error rate (higher than any service ChER at desired QoS) such that in the event that the initial OLT setting is too high outer-loop 2 will drive down the power until the first error is encountered. Following this the process will automatically set its own suitable ChER Target . Care must be taken therefore to ensure that the initial value of ChER Target does not enter the ChER Target filter. In the case that the initial OLT target is too low, errors will be encountered and the process will adapt itself accordingly.
The function performed by outer-loop 2 is very simple. It accepts two inputs: (i) the filtered version of ReEnc_ChER, and (ii) ChER Target . Outer-loop 2 simply compares these two values and adjusts the OLT accordingly.
It may be desirable that the value of Δ small per second is similar to the step-down size Δ per second used in the ‘sawtooth’ algorithm for speech services in order to ensure that both algorithms have similar channel-tracking capability.
Simulation tests have shown that power control utilising the above-described dual loop (DOLAP) scheme allows desired QoS to be maintained for low-FER/high-data-rate services. The simulation tests also showed that power control utilising the above-described dual loop (DOLAP) scheme coped well with changes in channel conditions, the control loops adapting to the changes without the need for CRC failure.
It will be appreciated that although the invention has been described above in the context of a CDMA system, the system does not need to be exclusively CDMA. For example, the invention could be used in a hybrid CDMA/TDMA system.
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An apparatus and method for power control in a CDMA system for radio communication between a first station and a second station. At the first station an indication of the received power of signals from the second station is communicated to the second station, and at the second station the indication of received power is received and its transmission power is accordingly modified. An inner control loop produces a power control metric estimate, and an outer control loop produces an outer loop threshold signal (OLT) dependent on received quality of service (QoS). The outer control loop means produces a channel error rate signal (ChER) whereby to track channel variations. The power control is capable of compensating for variations in the channel type and speed. A dual outer-loop scheme allows desired QoS to be maintained for low-FER/high-data-rate services.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/886,781 entitled “SYSTEM AND METHOD FOR STREAMING EVENTS IN A TRANSACTION-BASED SYSTEM,” filed on May 3, 2013, which claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 61/779,330 entitled “SYSTEM AND METHOD FOR STREAMING EVENTS IN A TRANSACTION-BASED SYSTEM,” filed Mar. 13, 2013, the contents of each of the applications are incorporated by reference herein in their entirety.
BACKGROUND
[0002] There are many different methods for performing transactions within a financial system. For instance, there are a number of disparate systems that store commercial transactions that are performed in a variety of store locations.
SUMMARY
[0003] According to one aspect, it is appreciated that many of the systems are not updated in real time with information from various store locations. For instance, the user may, when accessing a commercial website, desire to locate a particular item is sold at a retail store location. However, because the website is unable to accurately determine how many items are located at the commercial retail location, the website may process one or more transactions based on incorrect business knowledge at the time of the transaction. Many of the systems that are used to perform transactions are not easily connected, and do not communicate in real time. Frequently, information such as pricing, availability, sales, items on hand, among other information is communicated in a batch mode (e.g., at the end of a sales day). Such information is typically communicated one-way between a store to a home office. It is appreciated that some of these data elements are hours or days old, and the staleness of this data may cause consistency issues for applications and services in a multichannel ecosystem.
[0004] Therefore, it would be beneficial for many of these disparate systems to have the capability of updating each other in real time or near real time, with transaction information as they occur. According to one aspect of the present invention, a mechanism is provided to efficiently stream events in near real time from or more sources to one or more central/regional event stores. The event source could be an application, database, file system, a database, file system, memory or any other type of event source. In one embodiment, a distributed system is provided that provides the capability of transmitting events from stores and data centers as events occur in those subsystems. In one implementation, these events are lightweight and are streamed in near real time. Such a capability enables provisioning consistent data across multiple channels for Online Transaction Processing (OLTP) and analytical applications.
[0005] According to one embodiment of the present invention, event source components are added to legacy systems, allowing those systems to source events in a real-time manner. In this way, recoding of existing systems is minimized, and interfaces are provided for sending and receiving transaction events.
[0006] According to another embodiment of the present invention, an ability may be provided to stream data from multiple data sources to a central location. In another embodiment, a system may be provided to source multiple types of events such as file-based, database, and other event types in a number of different protocols to a data sink. Further, a buffering capability is provided in the case in particular data target is unavailable. Also in another implementation, and ability may be provided for managing and monitoring data sources and target from a central location. In yet another implementation, open source components may be used to construct all or part of the distributed system.
[0007] According to one aspect of the present invention, a distributed system is provided comprising one or more distributed systems, each of the distributed systems including an event generator, the event generator being adapted to stream transaction events occurring in real time, and a central manager comprising an event receiver, the event receiver being adapted to receive one or more streams of transactions from the one or more distributed systems and commit the streams of transactions to one or more databases wherein the event generator of at least one of the one more distributed systems comprises an event emitter that creates one or more events based on one or more transactions that occur at a location associated with the at least one distributed system.
[0008] According to one embodiment of the present invention, the event generator further comprises a plurality of event sources that receive the created one or more events and generates a stream of transaction events. According to another embodiment, the stream of transaction events are communicated to the event receiver of the central manager. According to another embodiment, the plurality of event sources comprises a UDP event source that is capable of transmitting UDP events to a UDP event receiver of the central manager. In yet another embodiment, the plurality of event sources comprises a TCP event source that is capable of transmitting TCP events to a TCP event receiver of the central manager. In another embodiment, the plurality of event sources comprises a file event source that is capable of transmitting file events to a file event receiver of the central manager. In another embodiment, the plurality of event sources comprises a database event source that is capable of transmitting database events to a database event receiver of the central manager.
[0009] According to another embodiment, the event generator is adapted to receive a locally-committed event and stream the locally-committed event to the central manager in real time. According to another embodiment, the one or more distributed systems are located in one or more commercial store locations, and wherein the one or more distributed systems are adapted to process events associated with transactions occurring at the one or more commercial store locations. According to another embodiment, the central manager is adapted to communicate information associated with the one or more streams of transactions to one or more external systems.
[0010] According to another embodiment, the central manager is adapted to receive transactions from the one or more external systems. According to another embodiment, the central manager is adapted to update a website with real-time information associated with the one or more commercial store locations.
[0011] According to another aspect of the present invention, a method is provided for processing events in a distributed system, the method comprising acts of generating, by an event generator of at least one system in a distributed system network, a stream of transaction events occurring in real time, receiving, by an event receiver of a central manager, one or more streams of transactions from the one or more distributed systems and committing the streams of transactions to one or more databases, and creating, by an event emitter of the at least one system in the distributed system one or more events based on one or more transactions that occur at a location associated with the at least one distributed system.
[0012] According to one embodiment of the present invention, the method further comprises an act of receiving, by a plurality of event sources, the created one or more events and generating a stream of transaction events. In another embodiment, the method further comprises an act of communicating the stream of transaction events to the event receiver of the central manager. In another embodiment, the plurality of event sources comprises a UDP event source, and the method further comprises an act of transmitting UDP events by the UDP event source to a UDP event receiver of the central manager. In another embodiment, the plurality of event sources comprises a TCP event source, and wherein the method further comprises an act of transmitting TCP events by the TCP event source to a TCP event receiver of the central manager. In another embodiment, the plurality of event sources comprises a file event source, and the method further comprises an act of transmitting file events by the file event source to a file event receiver of the central manager. In another embodiment, the plurality of event sources comprises a database event source, and the method further comprises an act of transmitting database events by the database event source to a database event receiver of the central manager.
[0013] According to another embodiment, the method further comprises an act of receiving, by the event generator, a locally-committed event and streaming the locally-committed event to the central manager in real time. According to another embodiment, the one or more distributed systems are located in one or more commercial store locations, and wherein the method further comprises an act of processing, by the one or more distributed systems, events associated with transactions occurring at the one or more commercial store locations. According to another embodiment, the method further comprises an act of communicating, by the central manager, information associated with the one or more streams of transactions to one or more external systems.
[0014] According to another embodiment, the method further comprises an act of receiving, by the central manager, transactions from the one or more external systems. According to another embodiment, the method further comprises an act of updating, by the central manager, a website with real-time information associated with the one or more commercial store locations.
[0015] Still other aspects, examples, and advantages of these exemplary aspects and examples, are discussed in detail below. Moreover, it is to be understood that both the foregoing information and the following detailed description are merely illustrative examples of various aspects and examples, and are intended to provide an overview or framework for understanding the nature and character of the claimed aspects and examples. Any example disclosed herein may be combined with any other example in any manner consistent with at least one of the objects, aims, and needs disclosed herein, and references to “an example,” “some examples,” “an alternate example,” “various examples,” “one example,” “at least one example,” “this and other examples” or the like are not necessarily mutually exclusive and are intended to indicate that a particular feature, structure, or characteristic described in connection with the example may be included in at least one example. The appearances of such terms herein are not necessarily all referring to the same example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Various aspects of at least one example are discussed below with reference to the accompanying figures, which are not intended to be drawn to scale. The figures are included to provide an illustration and a further understanding of the various aspects and examples, and are incorporated in and constitute a part of this specification, but are not intended as a definition of the limits of a particular example. The drawings, together with the remainder of the specification, serve to explain principles and operations of the described and claimed aspects and examples. In the figures, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every figure. In the figures:
[0017] FIGS. 1A-1B are block diagrams showing a system for streaming events within a transaction-based system according to various aspects of the present invention;
[0018] FIG. 2 shows a process for streaming events in a transaction-based system according to the to various embodiments of the present invention;
[0019] FIG. 3 shows one implementation of a distributed system including a central location and one or more regional store locations according to various embodiments of the present invention;
[0020] FIG. 4 shows an example implementation of a distributed system according to various embodiments of the present invention;
[0021] FIG. 5 shows an example system architecture of a distributed system according to one embodiment of the present invention;
[0022] FIG. 6 shows another example of the architecture of a distributed system according to one embodiment of the present invention;
[0023] FIG. 7 shows an example computer system with which various aspects of the invention may be practiced; and
[0024] FIG. 8 shows an example storage system capable of implementing various aspects of the present invention.
DETAILED DESCRIPTION
[0025] FIG. 1 shows a block diagram of a system 100 suitable for implementing various aspects of the present invention. In particular, according to various embodiments consistent with principles of the present invention, a number of constructs are provided that provide for lightweight communication between entities within a commercial transaction system. Such lightweight communications may include for example, relatively small messages having small payloads that contain data.
[0026] System 101 (e.g., event aggregator system 101 ) may include one or more components including an event provisioning layer 103 , an event store 104 , and a management monitoring subsystem 105 , and an event cache 110 . The event provisioning layer is an abstraction layer that serves events on demand to one or more systems. Event store 104 is a persistent store of the event data, usually found in a central management system. Further, 101 may include one or more event sinks (e.g., event sinks A-F (items 106 A- 106 F)) that are adapted to receive events from one or more event sources. Further, such event sinks may be configured to receive events outside of the distributed system and may be capable of transmitting events to other systems or applications.
[0027] System 101 may be coupled to one or more remote systems (e.g., remote systems 102 A- 102 B). Such remote systems may include one or more event emitters (e.g., event emitter 109 ) that can generate a number of different types of events. Event emitters may include, for example, hardware, software, or combinations thereof that are capable of indicating the occurrence of a particular event. In one embodiment, an event emitter may be a small portion of code installed on the remote system that receives events as they happen in a customized transaction system (e.g., a point-of-sale (POS) system that processes transactions such as item sales at a point-of-sale location). Depending on the type of transaction and the type of systems involved, events (e.g., events 108 ) may be generated as file-based events, database events, UDP events or TCP events. It should be appreciated however, that other types of events may be generated and this list of events is not exhaustive. One more components may be provided on the remote system for communicating one or more event types. For instance, sources 107 may be provided that support communication of file-based events, database events, UDP events or TCP events. It should be appreciated that any number of remote systems with any number of sources can be used.
[0028] FIG. 2 shows a process 200 for streaming events in a transaction-based system according to various embodiments of the present invention. To accomplish such a process, one or more agents (e.g., a process running on the source or target) may be provided at the event source or target. An event source agent executes on the source system, and is responsible for sending events to a next destination (or “hop”). An event sink agent is a process that is used to transmit events to the destination.
[0029] To begin, an event emitter 201 emits an event to get the start of a transaction. The event is “put” to a source 202 located on the remote system. The transaction is committed at the remote system, and shortly after, the event is communicated to a sink agent 203 located on another system (e.g., an event aggregator system 101 ).
[0030] Agent 203 receives the event and starts committing the transaction on the other system. In one embodiment, an event cache 204 is provided that caches events on the system (e.g., system 101 ). The cache temporarily stores events and event data until it can be successfully relayed and/or stored in a data storage location. After receipt and potential caching, the event is transacted to an event store 205 . The event store is, according to one embodiment, located in a persistent store on a host (e.g., a server, cloud-based store, or other medium).
[0031] A create/update event occurs that creates and/or updates the event in the store. Eventually, the receipt transaction is committed to long-term event storage on a central system (e.g., system 101 ). After that time, event data may be proliferated to other systems in a similar manner, and may be available to systems to perform various functions (e.g., an inventory function, sales estimation function, among others). Because transaction event data is communicated asynchronously by multiple sources in near real time, a snapshot of the system state any particular point in time is more accurate than a system having traditional destaged updates. Further, the central system may be capable of matriculating updated event data to external systems (e.g., a website) for the purposes of supporting Internet-based transactions with customers (e.g., sales, inventory location at particular store locations, etc.).
[0032] FIG. 3 shows one implementation of a distributed system including a central location and one or more regional store locations according to various embodiments of the present invention. For instance, a system 300 may be provided that includes a central location system 301 which is coupled to one or more regional stores (e.g., regional stores 1-3 (items 302 A- 302 C). In one implementation, source and sink components may be implemented using the well-known Apache Flume product, which is an open source Java-based product that is capable of streaming data from multiple sources to a single source and vice versa. In another implementation, the event store located, for instance, at a regional home office may include a series of Flume-based sink processes and an event store implemented using the well-known Cassandra open source NOSQL database. The event database may be capable of also receiving and processing bulk/batch data from other systems. At the regional home office, an Apache Hadoop HDFS system (the Hadoop Distributed File System (or HDFS)) may be used to provide high-throughput access to event data (e.g., from analytics programs or other applications/systems). Further, DataPower systems (e.g., XC-10 (security and event service layer), XI50 (event cache appliance)) may be used as a data cache, and a security and event service layer.
[0033] However, although particular commercial products are shown, it should be appreciated that other implementations may be used, and such implementations are within the spirit and scope of the present invention. For instance, the well-known SymmetricDS product may be used for asynchronous data replication of event data. Further, rather than an event-based architecture, point-to-point messaging using the well-known IBM WebSphere MQ infrastructure may be used to communicate transaction data.
[0034] FIG. 4 shows an example implementation of a distributed system according to various embodiments of the present invention. In particular, FIG. 4 shows a store 401 coupled to a home office 402 . Store applications may be, for example, mostly written in C, C++, or some other high-level language. The POS controller and SMART system of an ISP may include one or more C, C++ or other language connectors that communicate (e.g., using the well-known Apache Thrift rpc framework) to a connector (e.g., that may be Java-based). The Flume product may be implemented as an event distributor and may receive events from the connector using the well-known Apache Avro serialization protocol. The Flume Nodes (Event Distributor and Event Collector) may communicate event information between them, and a prime node may be provided that serves as a master event manager and monitoring system to ensure events are communicated and committed between systems. Similar to the implementation discussed above with respect to FIG. 3 , system 402 may implement an event storage using the Cassandra product and may make event data available using Apache HDFS.
[0035] Other implementations may be performed, such as those shown in FIGS. 5 and 6 . In particular, FIG. 5 shows a home office system 501 having an event cache 505 (e.g., a DataPower XI50 appliance) and an event store 506 which can be implemented on virtual machines on a clustered system 508 (e.g., a Cassandra cluster). The system may implement Flume collectors as a Linux server that collects SLAP events including event data relating to transactions. Such events may be communicated from a store location using a Flume Distributor system 509 that in turn receives events from ISP system 511 . A Point-of-Sale (POS) controller 510 initiates the event data based on a transaction conducted at the store location.
[0036] Systems located at a home office 501 could provide event data in turn to one or more external systems (e.g., via the Internet 503 ) through one or more systems. In one implementation, the system uses a firewall 504 coupled to the Internet (e.g., a DataPower XS40 security gateway appliance) to provide external access to event data. FIG. 6 shows a more robust implementation, using two home office implementations ( 601 , 602 ), each having respective event caches ( 606 , 610 ), event stores implemented on virtual machines (607, 611) on separate clusters ( 609 , 613 ). SLAP events may be communicated in parallel from one or more stores (e.g., store 603 ) to the individual home office locations. A coordination protocol may be implemented between the event store locations to ensure consistency between the event stores. Firewall 604 may also perform load sharing/failover functions by directing requests (e.g., requests provided through the Internet 605 ) to either home office ( 601 , 602 ). Similar to store implementation 502 , store implementation 603 may include a POS controller ( 615 ), ISP system ( 616 ), and Flume distributor ( 614 ) that communicates event data.
Example Computer Implementations
[0037] Processes described above are merely illustrative embodiments of systems that may be used to manage events in a distributed system. Such illustrative embodiments are not intended to limit the scope of the present invention, as any of numerous other implementations for performing the invention. None of the claims set forth below are intended to be limited to any particular implementation of an event processing system, unless such claim includes a limitation explicitly reciting a particular implementation.
[0038] Processes and methods associated with various embodiments, acts thereof and various embodiments and variations of these methods and acts, individually or in combination, may be defined by computer-readable signals tangibly embodied on a computer-readable medium, for example, a non-volatile recording medium, an integrated circuit memory element, or a combination thereof. According to one embodiment, the computer-readable medium may be non-transitory in that the computer-executable instructions may be stored permanently or semi-permanently on the medium. Such signals may define instructions, for example, as part of one or more programs, that, as a result of being executed by a computer, instruct the computer to perform one or more of the methods or acts described herein, and/or various embodiments, variations and combinations thereof. Such instructions may be written in any of a plurality of programming languages, for example, Java, Visual Basic, C, C#, or C++, Fortran, Pascal, Eiffel, Basic, COBOL, etc., or any of a variety of combinations thereof. The computer-readable medium on which such instructions are stored may reside on one or more of the components of a general-purpose computer described above, and may be distributed across one or more of such components.
[0039] The computer-readable medium may be transportable such that the instructions stored thereon can be loaded onto any computer system resource to implement the aspects of the present invention discussed herein. In addition, it should be appreciated that the instructions stored on the computer-readable medium, described above, are not limited to instructions embodied as part of an application program running on a host computer. Rather, the instructions may be embodied as any type of computer code (e.g., software or microcode) that can be employed to program a processor to implement the above-discussed aspects of the present invention.
[0040] Various embodiments according to the invention may be implemented on one or more computer systems. These computer systems may be, for example, general-purpose computers such as those based on Intel PENTIUM-type processor, Motorola PowerPC, Sun UltraSPARC, Hewlett-Packard PA-RISC processors, ARM Cortex processor, Qualcomm Scorpion processor, or any other type of processor. It should be appreciated that one or more of any type computer system may be used to partially or fully automate management of events and event data according to various embodiments of the invention. Further, the event management system may be located on a single computer or may be distributed among a plurality of computers attached by a communications network.
[0041] The computer system may include specially-programmed, special-purpose hardware, for example, an application-specific integrated circuit (ASIC). Aspects of the invention may be implemented in software, hardware or firmware, or any combination thereof. Further, such methods, acts, systems, system elements and components thereof may be implemented as part of the computer system described above or as an independent component.
[0042] A computer system may be a general-purpose computer system that is programmable using a high-level computer programming language. Computer system may be also implemented using specially programmed, special purpose hardware. In a computer system there may be a processor that is typically a commercially available processor such as the well-known Pentium class processor available from the Intel Corporation. Many other processors are available. Such a processor usually executes an operating system which may be, for example, the Windows NT, Windows 2000 (Windows ME), Windows XP, Windows Vista, Windows 7, or Windows 8 operating systems available from the Microsoft Corporation, MAC OS X Snow Leopard, MAC OS X Lion operating systems available from Apple Computer, the Solaris Operating System available from Sun Microsystems, iOS, Blackberry OS, Windows 7 Mobile or Android OS operating systems, or UNIX available from various sources. Many other operating systems may be used.
[0043] Some aspects of the invention may be implemented as distributed application components that may be executed on a number of different types of systems coupled over a computer network. Some components may be located and executed on mobile devices, servers, tablets, or other system types. Other components of a distributed system may also be used, such as databases (e.g., the mongoDB database available from 10gen, Inc.), cloud services, or other component types.
[0044] The processor and operating system together define a computer platform for which application programs in high-level programming languages are written. It should be understood that the invention is not limited to a particular computer system platform, processor, operating system, or network. Further, it should be appreciated that multiple computer platform types may be used in a distributed computer system that implement various aspects of the present invention. Also, it should be apparent to those skilled in the art that the present invention is not limited to a specific programming language or computer system. Further, it should be appreciated that other appropriate programming languages and other appropriate computer systems could also be used.
[0045] One or more portions of the computer system may be distributed across one or more computer systems coupled to a communications network. These computer systems also may be general-purpose computer systems. For example, various aspects of the invention may be distributed among one or more computer systems configured to provide a service (e.g., servers) to one or more client computers, or to perform an overall task as part of a distributed system. For example, various aspects of the invention may be performed on a client-server system that includes components distributed among one or more server systems that perform various functions according to various embodiments of the invention. These components may be executable, intermediate (e.g., IL) or interpreted (e.g., Java) code which communicate over a communication network (e.g., the Internet) using a communication protocol (e.g., TCP/IP). Certain aspects of the present invention may also be implemented on a cloud-based computer system (e.g., the EC2 cloud-based computing platform provided by Amazon.com), a distributed computer network including clients and servers, or any combination of systems.
[0046] It should be appreciated that the invention is not limited to executing on any particular system or group of systems. Also, it should be appreciated that the invention is not limited to any particular distributed architecture, network, or communication protocol.
[0047] Various embodiments of the present invention may be programmed using an object-oriented programming language, such as SmallTalk, Java, C++, Ada, or C# (C-Sharp). Other object-oriented programming languages may also be used. Alternatively, functional, scripting, and/or logical programming languages may be used. Various aspects of the invention may be implemented in a non-programmed environment (e.g., documents created in HTML, XML or other format that, when viewed in a window of a browser program, render aspects of a graphical-user interface (GUI) or perform other functions). Various aspects of the invention may be implemented as programmed or non-programmed elements, or any combination thereof.
[0048] Further, on each of the one or more computer systems that include one or more components of distributed system 100 , each of the components may reside in one or more locations on the system. For example, different portions of the components of system 100 may reside in different areas of memory (e.g., RAM, ROM, disk, etc.) on one or more computer systems. Each of such one or more computer systems may include, among other components, a plurality of known components such as one or more processors, a memory system, a disk storage system, one or more network interfaces, and one or more busses or other internal communication links interconnecting the various components.
[0049] Any number of systems of distributed system 100 (or other systems described above) may be implemented on a computer system described below in relation to FIGS. 7 and 8 . In particular, FIG. 7 shows an example computer system 500 used to implement various aspects. FIG. 7 shows an example storage system that may be used.
[0050] System 700 is merely an illustrative embodiment of a computer system suitable for implementing various aspects of the invention. Such an illustrative embodiment is not intended to limit the scope of the invention, as any of numerous other implementations of the system, for example, are possible and are intended to fall within the scope of the invention. For example, a virtual computing platform may be used. None of the claims set forth below are intended to be limited to any particular implementation of the system unless such claim includes a limitation explicitly reciting a particular implementation.
[0051] For example, various aspects of the invention may be implemented as specialized software executing in a general-purpose computer system 700 such as that shown in FIG. 7 . The computer system 700 may include a processor 703 connected to one or more memory devices 704 , such as a disk drive, memory, or other device for storing data. Memory 704 is typically used for storing programs and data during operation of the computer system 700 . Components of computer system 700 may be coupled by an interconnection mechanism 705 , which may include one or more busses (e.g., between components that are integrated within a same machine) and/or a network (e.g., between components that reside on separate discrete machines). The interconnection mechanism 705 enables communications (e.g., data, instructions) to be exchanged between system components of system 700 . Computer system 700 also includes one or more input devices 702 , for example, a keyboard, mouse, scanner, trackball, microphone, touch screen, and one or more output devices 701 , for example, a printing device, display screen, and/or speaker. The system may also include any specialized components depending on the application, including any barcode reader, magnetic stripe reader, receipt printer, hand-held or fixed scanners, pin entry devices (PED), or other device types. In addition, computer system 700 may contain one or more interfaces (not shown) that connect computer system 700 to a communication network (in addition or as an alternative to the interconnection mechanism 705 ).
[0052] The storage system 706 , shown in greater detail in FIG. 8 , typically includes a computer readable and writeable nonvolatile recording medium 801 in which signals are stored that define a program to be executed by the processor or information stored on or in the medium 801 to be processed by the program. The medium may, for example, be a disk or flash memory. Typically, in operation, the processor causes data to be read from the nonvolatile recording medium 801 into another memory 802 that allows for faster access to the information by the processor than does the medium 801 . This memory 802 is typically a volatile, random access memory such as a dynamic random access memory (DRAM) or static memory (SRAM). It may be located in storage system 706 , as shown, or in memory system 704 , not shown. The processor 703 generally manipulates the data within the integrated circuit memory 704 , 802 and then copies the data to the medium 801 after processing is completed. A variety of mechanisms are known for managing data movement between the medium 801 and the integrated circuit memory element 704 , 802 , and the invention is not limited thereto. The invention is not limited to a particular memory system 704 or storage system 706 .
[0053] The computer system may include specially-programmed, special-purpose hardware, for example, an application-specific integrated circuit (ASIC). Aspects of the invention may be implemented in software, hardware or firmware, or any combination thereof. Further, such methods, acts, systems, system elements and components thereof may be implemented as part of the computer system described above or as an independent component.
[0054] Although computer system 700 is shown by way of example as one type of computer system upon which various aspects of the invention may be practiced, it should be appreciated that aspects of the invention are not limited to being implemented on the computer system as shown in FIG. 7 . Various aspects of the invention may be practiced on one or more computers having a different architecture or components that that shown in FIG. 7 .
[0055] Computer system 700 may be a general-purpose computer system that is programmable using a high-level computer programming language. Computer system 700 may be also implemented using specially programmed, special purpose hardware. In computer system 700 , processor 703 is typically a commercially available processor such as the well-known Pentium, Core, Core Vpro, Xeon, or Itanium class processors available from the Intel Corporation. Many other processors are available. Such a processor usually executes an operating system which may be, for example, the Windows NT, Windows 2000 (Windows ME), Windows XP, Windows Vista, Windows 7 or Windows 8 operating systems available from the Microsoft Corporation, MAC OS Snow Leopard, MAC OS X Lion operating systems available from Apple Computer, the Solaris Operating System available from Sun Microsystems, iOS, Blackberry OS, Windows 7 or 8 Mobile or Android OS operating systems, or UNIX available from various sources. Many other operating systems may be used.
[0056] The processor and operating system together define a computer platform for which application programs in high-level programming languages are written. It should be understood that the invention is not limited to a particular computer system platform, processor, operating system, or network. Also, it should be apparent to those skilled in the art that the present invention is not limited to a specific programming language or computer system. Further, it should be appreciated that other appropriate programming languages and other appropriate computer systems could also be used.
[0057] One or more portions of the computer system may be distributed across one or more computer systems (not shown) coupled to a communications network. These computer systems also may be general-purpose computer systems. For example, various aspects of the invention may be distributed among one or more computer systems configured to provide a service (e.g., servers) to one or more client computers, or to perform an overall task as part of a distributed system. For example, various aspects of the invention may be performed on a client-server system that includes components distributed among one or more server systems that perform various functions according to various embodiments of the invention. These components may be executable, intermediate (e.g., IL) or interpreted (e.g., Java) code which communicate over a communication network (e.g., the Internet) using a communication protocol (e.g., TCP/IP).
[0058] It should be appreciated that the invention is not limited to executing on any particular system or group of systems. Also, it should be appreciated that the invention is not limited to any particular distributed architecture, network, or communication protocol.
[0059] Various embodiments of the present invention may be programmed using an object-oriented programming language, such as SmallTalk, Java, C++, Ada, or C# (C-Sharp). Other object-oriented programming languages may also be used. Alternatively, functional, scripting, and/or logical programming languages may be used. Various aspects of the invention may be implemented in a non-programmed environment (e.g., documents created in HTML, XML or other format that, when viewed in a window of a browser program, render aspects of a graphical-user interface (GUI) or perform other functions). Various aspects of the invention may be implemented using various Internet technologies such as, for example, the well-known Common Gateway Interface (CGI) script, PHP Hyper-text Preprocessor (PHP), Active Server Pages (ASP), HyperText Markup Language (HTML), Extensible Markup Language (XML), Java, JavaScript, Asynchronous JavaScript and XML (AJAX), Flash, and other programming methods. Further, various aspects of the present invention may be implemented in a cloud-based computing platform, such as the well-known EC2 platform available commercially from Amazon.com, Seattle, Wash., among others. Various aspects of the invention may be implemented as programmed or non-programmed elements, or any combination thereof.
[0060] Having thus described several aspects of at least one embodiment of this invention, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description and drawings are by way of example only.
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A system is provided that permits events to be propagated between systems in near real time for the purpose of ensuring consistency in a transaction-based environment. In one implementation, transactions are streamed between systems using a lightweight protocol shortly after they are processed, rather than being communicated in a one-way batch mode as is typically done in conventional retail store systems.
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FIELD OF THE INVENTION
The present invention relates to a data input device for inputting data to a computer system, and to methods of operating it. The data input device is further arranged to have a data storage function.
BACKGROUND OF INVENTION
Recently there has been great interest in providing data storage devices using which a user is able to transfer data between components of a computer system, or between computer systems.
For example, one of the present inventors has proposed in PCT application PCT/SG01/00136, published as WO 03/003141, entitled “Method and devices for data transfer” (the disclosure of which is incorporated herein by reference) a data storage device for use in a computer system including a computer device and one or more other external electronic devices. The external devices are of the type referred to as “slave devices”, and examples of such electronic devices include a camera, a video camera, a organiser, an MP3 player, or a PDA (personal assistant). The data storage device includes a wireless transceiver (transducer) for receiving data (which the data storage device stores), and for transmitting data stored within it. The computer device too, and each of the other electronic devices, includes a respective wireless transducer. Thus, the data storage device can be used for transferring data between the computer device and the various external devices. Since the storage device is substantially devoted to storage of data, it can accommodate a memory which is larger than in most other portable electronic items. Furthermore, since the data transfer is wireless, physical connectors (such as cables, sockets and plugs) are not required, so data can be transferred within the computer system despite the very large number of existing standards for physical connectors.
SUMMARY OF THE INVENTION
Although the data storage device proposed in PCT/SG01/00136 has proved practically useful, it constitutes an additional element which a user of the computer system has to obtain and use (e.g. to carry around when the computer system is to be transported).
The present invention aims to provide a new and useful data storage device.
In general terms, the invention proposes that the data storage device should be shaped in the form of a stylus, that is having a tip for indicating a position. The stylus permits the device to be used for data entry to a electronic device which measures the position of the stylus tip (e.g. a device having a touch sensitive surface). Thus, the data storage device can be used in place of a conventional stylus. In other words, a user of an electronic device which traces the position of a stylus is able to enjoy the advantages of a wireless memory storage device without being obliged to use an additional component.
Specifically, a first expression of the invention is a data storage device having:
a non-volatile memory of at least 8 Mbyte, a wireless transceiver for transmitting and receiving data; a control processor for storing data received by the wireless transceiver in the memory, and for extracting data from the memory and transmitting it to the wireless transceiver for transmission; and a housing having an outer profile including a stylus portion defining a tip.
Preferably, the data storage device further includes at least one biometric sensor for recording a biometric characteristic of a user, and a verification processor for comparing the biometric characteristic with a characteristic stored by the sensor, the verification processor controlling whether the data storage device performs at least one of its functions in dependence upon whether the recorded biometric characteristic matches the stored characteristic.
For example, the biometric sensor may be a fingerprint sensor, and the data storage device may include a verification processor arranged to compare a fingerprint received by the fingerprint sensor with a stored fingerprint.
Preferably, the data storage device only transmits data stored within it when the verification processor determines that there is a match between the recorded biometric characteristic and the stored characteristic.
Note that it is not indispensable to the invention that the verification processor and control processor are physically different units. The verification processor and the control processor may, if desired, be different functions of a single integrated circuit (master control unit). Alternatively, any other number of integrated circuits may be used to implement together the function of the control processor and verification processor.
The device may include the capability to compress/decompress data which is to be stored, or has been stored, in the non-volatile memory. This can be implemented by the processor which stores data into and retrieves data from the non-volatile memory, or alternatively by a dedicated microprocessor unit.
The device may be integrated with an image capturing device (camera) for generating data which can be stored in the non-volatile memory, and subsequently transmitted through the wireless transceiver.
The device may incorporate at least one smart card, for providing at least one enhanced security feature.
A second expression of the invention is a system including a data storage device as described above, and a first electronic device which is arranged to register the position of the stylus of the data storage device, so that the user can enter data to the first electronic device by moving the stylus, the first electronic device further including a wireless transceiver for exchanging data with the data storage device.
The first electronic device may for example have a surface, and means for detecting the movement of the stylus over the surface. For example, the surface may be touch sensitive.
One possibility is for the first electronic device to be a tablet PC, an organiser or a PDA (personal assistant).
In addition to the first electronic device, the system may comprise one or more further electronic devices which include respective wireless transceivers for exchanging data with the data storage device. Thus, the data storage device may be arranged as a “bridge”, which can be used to store data received from a first of the electronic devices and subsequently to transmit that data to a second of the electronic devices (optionally with some processing of the data within the data storage device, such as an encoding operation).
Preferably, the system is a computer system, in which one of the electronic devices is a PC, and other of the electronic devices are “slave devices” of the PC, such as the PDA.
Each of the wireless transceivers preferably operates by electromagnetic waves, and most preferably by RF or infra-red waves. In the former case, the transceiver may consist of an antenna and RF interface circuitry. Irrespective of the wireless waves employed, the transceiver may use any protocol presently in existence or which may become available in the future, for example it may be capable of sending and/or receiving signals in at least one of (i) IEEE802.11, (ii) Bluetooth, or (iii) irDA.
It is also possible that the data storage device may be capable of receiving/transmitting in multiple formats, so that it can interpret between two slave devices which use different formats.
Preferably, any of the electronic devices which includes an internal memory is arranged, upon that internal memory becoming full, or at least the amount of data passing a predefined limit, to initiate communication with the data storage device, so that the data can be transferred to the data storage device.
Preferably all communications carried out by the data storage device include a process of establishing the identity of the other device (computer device or slave device) using an ID code received from that device and compared with list of ID codes stored internally by the data storage device.
A third expression of the invention is a method of transferring data between a data storage device of the kind discussed above and another electronic device which incorporates means for tracking the position of the tip of the stylus, the method including at least one of the operations of:
(i) a transceiver of the other electronic device transmitting the data wirelessly to the transceiver of the data storage device, or (ii) the transceiver of the data storage device transmitting the data wirelessly to the transceiver of the data storage device.
BRIEF DESCRIPTION OF THE FIGURES
Preferred features of the invention will now be described, for the sake of illustration only, with reference to the following figures in which:
FIG. 1 is a schematic view of a computer system including data storage device which is a first embodiment of the invention;
FIG. 2 , which is composed of FIGS. 2( a ) and 2 ( b ), is schematic views of the data storage device of FIG. 1 ;
FIG. 3 shows the steps performed by the data storage device in a first method employing the system of FIG. 1 ;
FIG. 4 shows the steps performed by the data storage device in a second method employing the system of FIG. 1 ;
FIG. 5 shows the steps performed by the data storage device in a third method employing the system of FIG. 1 ;
FIG. 6 shows the processes of FIG. 4 or 5 from the point of view of a user;
FIG. 7 shows schematically a side view of a data storage device which is a second embodiment of the invention; and
FIG. 8 shows the internal construction of the embodiment of FIG. 7 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
Referring to FIG. 1 , a system embodying the invention includes a PC 1 having an antenna 3 . The system also includes a data storage device 5 , having an antenna 37 (not shown in FIG. 1 ). The system further includes a plurality of electronic (“slave”) devices 9 , 19 which are external to the computer device 1 and spatially separated from it, but which may usefully communicate data to and/or from the PC 1 . Each external device 9 , 19 has an antenna 11 . For simplicity only two slave devices 9 , 19 are illustrated in FIG. 1 . The data storage device 5 and each of the external devices 9 , 19 are portable. For example, their weight is preferably less than 1 kilogram each, and each preferably includes an internal power source such as a battery.
The PC 1 and the data storage device 5 can communicate using the antenna 3 and the antenna of the data storage device 5 . Similarly, the data storage device 5 and the external devices 9 , 19 can communicate using the antenna of the data storage device 5 and the antennas 11 . Both forms of communication may be using any of the communication protocols IEEE802.11, Bluetooth, irDA, etc. As described below, any of the slave devices 9 , 19 can send data selectively to the PC 1 or to any of the other slave devices 9 , 19 via the data storage device 5 . The PC 1 can send data to a selected one of the slave devices 9 , 19 via the data storage device. All of this communication is digital, and the data storage device 5 is for digital data. In addition, it is possible that the data may be sent in an encrypted form.
Note that at least one (and possibly all) of the slave devices 9 , 19 may not require two-way communication with other slave devices 9 , 19 or the PC 1 . For example, in the case of a slave device 9 which is a digital camera, the data transmitted via the master storage device 5 may largely (or exclusively) be from the digital camera to the PC 1 .
Turning now to FIG. 2 , the construction of the data storage device 5 is shown, respectively as a side view ( FIG. 2( a )) and as a block diagram ( FIG. 2( b )).
The device 5 includes an outer housing including a stylus portion 23 having a tip 25 . The antenna of the device 5 is not shown, but is preferably provided at or proximate the end of the device 5 which is opposite from the stylus portion 23 (i.e. at the other end of the housing). The exterior surface of the housing includes a fingerprint sensor 27 having a surface 29 which is substantially plush with the housing. When a user applies his finger to the surface 29 , the fingerprint is recorded.
The interior of the data storage device 5 includes a data storage module 31 , a microcontroller (master control unit) 33 in two-way communication with the data storage module 31 and with the fingerprint sensor 27 . The microcontroller 5 is further in communication with a transceiver 35 comprising an antenna 37 and RF interface circuitry 39 . The transceiver 35 is arranged for receiving an RF signal by the antenna 37 , and to extract digital data from it in the RF interface circuitry 39 , which passes the data to the microcontroller 33 , which stores it in the storage module 31 . When the data storage device 5 is to transmit data, the microcontroller 33 issues a signal to the storage module 31 which transmits data stored within it to the microcontroller 33 , which then passes the data to the transceiver 35 for transmission.
Optionally, the operations of the data storage device 5 (and in particular the operation of transmitting data via the transceiver 35 ) are only enabled in the case that fingerprint sensor 27 has recorded a fingerprint, transmitted it as fingerprint data to the microcontroller 33 , and the microcontroller has compared that fingerprint data to data pre-stored in the storage module 31 (or in some other memory, which is not shown).
The memory capacity of storage module 31 of the data storage device 5 may for example be at least 8 MB, at least 1 GB, at least 10 GB, or at least 20 GB. The storage module 31 of the storage device 5 can be, for example, a magnetic disk drive or any other suitable non-volatile data storage device, such as an electrically erasable programmable read only memory (EEPROM), a ferroelectric random access memory (FRAM), a magetoresistive random access memory (MRAM), or any other data storage device which may become available in the future.
Turning to FIG. 3 , a method using the system of FIG. 1 is shown. In this method, the data storage device 5 receives and stores data from one of the slave devices 9 , 19 . Initially, the data storage device 5 is in a waiting state 41 . In step 43 , the transceiver 35 receives data via the antenna 37 from the other of the devices 9 , 19 , and passes it to the microcontroller 33 .
In step 45 , the microcontroller 33 uses the fingerprint sensor 27 to verify the finger print of a user holding it. If the measured fingerprint does not match the fingerprint data stored in the storage module 31 , an error message is generated in step 47 , and the device returns to the waiting state 41 .
Otherwise, in step 49 , the device verifies an ID (password) of the slave device from the data it received (e.g. comparing the ID encoded in the data with an ID stored in a list in the storage module 31 ). If this verification process fails, the device moves to step 47 . Otherwise, the device passes to step 51 in which the microcontroller 33 creates a directory in the storage module 31 , and step 53 in which the device continues to receive data from the slave device 9 , 19 and stores it in the storage module 31 .
Turning to FIG. 4 , a second method using the system of FIG. 1 is shown. In this method, the data storage device 5 receives and stores data from the PC 1 . Initially, the data storage device 5 is in a waiting state 61 . In step 63 , the transceiver 35 (and thus the microcontroller 33 ) receives a write request via the antenna 37 from the PC 1 indicating that the user of the PC has used a touch screen, keyboard or mouse input device to signal that data is to be written from the PC 1 to the memory device 5 . The receipt of this request also initiates the next process step 65 .
In step 65 , the microcontroller 33 uses the fingerprint sensor 27 to verify the finger print of a user holding it. If the measured fingerprint does not match the fingerprint data stored in the storage module 31 , an error message is generated in step 67 , and the device returns to the waiting state 61 .
Otherwise, in step 69 , the device verifies an ID of the PC 1 within the write request it received (e.g. comparing a ID encoded in the request with an ID stored in the list in the storage module 31 ). If this verification process fails, the device moves to step 67 . Otherwise, the device passes to step 71 in which the microcontroller 33 receives data from the PC 1 using the transceiver 35 , and step 73 in which the microcontroller 33 stores the data in the storage module 31 .
Turning to FIG. 5 , a third method using the system of FIG. 1 is shown. In this method, the data storage device 5 transmits data to the PC 1 . Initially, the data storage device 5 is in a waiting state 81 . In step 83 , the transceiver 35 receives a read request via the antenna 37 from the PC 1 indicating that the user of the PC has used a touch screen, keyboard or mouse input device to signal that data is to be written to the PC 1 from the memory device 5 . The receipt of this request also initiates the next process step 85 .
In step 85 , the microcontroller 33 uses the fingerprint sensor 27 to verify the finger print of a user holding it. If the measured fingerprint does not match the fingerprint data stored in the storage module 31 , an error message is generated in step 87 , and the device returns to the waiting state 81 .
Otherwise, in step 89 , the device verifies an ID of the PC 1 within the request it received (e.g. comparing a ID encoded in the request with an ID stored in the list in the storage module 31 ). If this verification process fails, the device moves to step 87 . Otherwise, the device passes to step 91 in which the microcontroller 33 receives data from storage module 31 , and in step 93 sends it to the PC 1 using the transceiver 35 .
A process very similar to that shown in FIG. 5 occurs in the case that data is to be transmitted to one of the slave devices. It differs in that step 83 is replaced by a step in which the storage device 5 receives a read request from the slave device and passes it to the microcontroller 33 , step 89 is replaced by a step in which the identity of the slave device is confirmed using an ID of the slave device, and step 93 is replaced by a step in which the data is transmitted by the transceiver 35 to the slave device.
FIGS. 4 and 5 showed the process of transferring data between the data storage device 5 and the PC 1 from the point of view of the device 5 . However, referring to FIG. 6 , these processes are shown from the point of view of a user.
In step 101 , a user brings the stylus close to the PC, within the range of their respective transceivers 3 , 35 . In step 103 , a pop-up message appears on the screen of the PC asking the user to verify his identity by placing his finger on the sensor 27 of the stylus 5 .
In step 105 , a determination is made by the microcontroller 33 of whether there is a match. If not, in step 107 the user is invited to retry, or terminate the attempt.
Otherwise in step 109 , the operating system of the PC (or other host system) is configured to recognise an external drive (corresponding to the storage module 31 ), and in step 110 the user can read or write to/from the storage module 31 of the stylus 5 by the touch screen, keyboard or mouse.
In addition to these functions, the user is additionally able to enter data into a electronic device such as the PDA 19 which is able to trace the movements of the tip 25 of the stylus portion 23 . The way in which the electronic device 19 tracks the position of the tip 25 may be according to any known technique, or any which may become available in the future. For example, it may be by providing a touch sensitive surface 15 on the PDA 19 , so that the user can stroke this surface with the tip 25 . Alternatively, the position of the tip 25 may for example be detected by a sonar or radar technique. The user thus has all the functionality available from the stylus of any known system, in addition to the data storage capacity of the data storage device 5 .
FIG. 7 shows a second embodiment of a data storage device according to the invention. Items of FIG. 7 corresponding to those of FIG. 2( a ) are given reference numerals 100 higher. The data storage device incorporates a digital camera device 140 within the same housing. The digital camera device 140 is capable of taking images (still images, and/or in certain versions of the embodiment moving images). The device may also include a sound receiving device (microphone) 142 capable of recording audio sound.
The functional structure of the second embodiment is as shown in FIG. 8 . Elements corresponding to those of FIG. 2( b ) are given reference numerals 100 higher. Data representing the images and/or sound captured by the camera 140 and microphone 142 are stored by the micro-controller 133 in the memory 131 . As in the first embodiment, RF interface circuitry is provided, for receiving data from and transmitting data to an antenna 37 .
Note that the device preferably has all the functionality of the first embodiment. That is, it is able to receive data via the aerial 137 , store it in the memory unit 131 , and then re-transmit it, so that in this way the data storage device can transfer data among a plurality of devices.
A further possible enhancement of both of the first and second embodiments of the invention is that they may be provided with the capability to compress data which is to be stored in the memory units 31 , 131 . This is related to the concept discussed in PCT patent application “System and Apparatus for Compressing and Decompressing Data Stored to a Portable Data Storage Device”, PCT/SG02/00086, filed 13 May 2002, the entire disclosure of which is incorporated herein by reference. The compression algorithm may for example be stored in a ROM memory and uploaded into the processors 33 , 133 and performed there. Alternatively, the device may contain a separate compression engine (not shown).
Optionally, in addition to data compression, the portable storage device is arranged to decompress the data before transmitting out of the device. Again this may be performed by the processors 33 , 133 , or by a decompression engine, which may in fact by the same microprocessor as the compression engine.
Another possible enhancement of both of the first and second embodiments of the invention is that the device may include some form of “smart card”, to provide one or more additional security functions, e.g. to detect some improper usage of the device and, upon this detection, to alter the functioning of the device, for example to inhibit the transmission of data from the memory modules 31 , 131 (or indeed to delete all data stored there).
Many forms of smart card are known, including for example cards which can sense that the housing of the device has been opened, and cards which contain identity information. Optionally, for example, the fingerprint sensing described above can be implemented using the smart card.
Note that, although the invention has been described above with reference to only two embodiments, many further variations are possible within the scope of the invention as will be clear to a skilled reader. For example, it is possible for the data storage device 5 to include a physical interface allowing it to be connected to another electronic device or apparatus allowing data to be transmitted into or out of the data storage device respectively from or to the other electronic device via the physical interface. For example, the physical interface may be a plug, such as a USB plug or a Firewire plug, which can be directly connected to a socket in the other electronic device.
Also, the data storage device 5 need not be limited to use within a single computer system, but may be used to transfer data between different computer systems, each of which may have one or more respective PCs and each of which may have one or more slave devices.
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A data storage device 5 having a storage capacity of at least 8 Mbyte is surrounded by a housing including a stylus portion 23 , having a tip 25 for indicating a position. The stylus permits the data storage device 5 to be used for data entry to a electronic device 19 such as a PDA which traces the position of the stylus tip. The data storage device 5 can be used in place of a conventional stylus. Thus, the user of the electronic device 19 which traces the position of a stylus is able to enjoy the advantages of a data storage device without being obliged to use an additional component.
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This is a division, of application Ser. No. 497,244, filed Aug. 14, 1974.
BACKGROUND OF THE INVENTION
This invention relates to novel ester derivatives of prostaglandin E 2 (hereinafter identified as "PGE 2 "), PGE 1 , and 13,14-dihydro-PGE 1 and their 15-methyl, 16-(or 16,16-di-)-methyl, and phenyl-substituted analogs, including the respective 15(R)epimers, and to processes for producing them.
PGE 2 is represented by the formula: ##SPC2##
A systematic name for PGE 2 is 7-{3α-hydroxy-2β-[ (3S)-3-hydroxy-trans-1-octenyl]-5-oxo-1α -cyclopentyl}-cis-5-heptenoic acid. PGE 2 is known to be useful for a variety of pharmacological and medical purposes, for example labor induction and abortion in pregnant animals, including humans, menstrual regulation in both pregnant and non-pregnant animals, including humans, reduction and control of gastric secretion, and as a hypotensive agent to reduce blood pressure in mammals, including humans. See Bergstrom et al., Pharmacol. Rev. 20, 1 (1968) and references cited therein. As to racemic PGE 2 , see for example W. P. Schneider, Chem. Commun. 304 (1969).
The 15(S)-15-methyl-PGE 2 analog and its 15(R) epimer are represented by the formula: ##SPC3##
Wherein M' is ##EQU5## following the usual convention wherein broken line attachment of hydroxy to the side chain at carbon 15 indicates the natural or S configuration and solid line attachment of hydroxy indicates the epi or R configuration. See for example Nugteren et al., Nature 212, 38 (1966) and Cahn, J. Chem. Ed. 41, 116 (1964). The 15(S)-15-methyl- and 15(R)-15-methyl-PGE 2 analogs in their optically active and racemic forms are known. See for example U.S. Pat. No. 3,728,382. These analogs are also useful for the above-described pharmacological purposes.
The 16-(or 16,16-di)methyl-PGE 2 analogs and their 15(R) epimers are represented by the formula: ##SPC4##
wherein M is ##EQU6## wherein R 3 is hydrogen or methyl, and wherein each of R 4 and R 5 is hydrogen or methyl, being the same or different. These 16-methyl- and 16,16-dimethyl-PGE 2 analogs and their 15(R) epimers in their optically active and racemic forms are available or can be prepared by methods known in the art. See for example German Pat. No. 2,217,044, Derwent Farmdoc No. 71483T.
The phenyl-substituted PGE 2 analogs and their 15(R) epimers are represented by the formula: ##SPC5##
wherein M is ##EQU7## wherein R 3 is hydrogen or methyl, and wherein C t H 2t represents a valence bond or alkylene of one to 10 carbon atoms, inclusive, with one to 7 carbon atoms, inclusive, between ##EQU8## and the phenyl ring. These substituted analogs and their 15(R) epimers in their optically active and racemic forms are available or can be prepared by methods known in the art. See for example German Pat. No. 2,154,309, Derwent Farmdoc No. 31279T.
PGE 1 is represented by the formula: ##SPC6##
and the PGE 1 analogs are represented similarly to the PGE 2 analogs above except that cis-CH=CH- in the carboxy acid side chain of formulas II, III, and IV is replaced by --CH 2 CH 2 -. These PGE 1 compounds are available or are prepared by methods known in the art. See for example E. J. Corey et al., J. Am. Chem. Soc. 90, 3245 (1968) and 92, 2586 (1970); U.S. Pat. Nos. 3,069,322, and 3,728,382; 3,598,858, J. E. Pike et al., J. Org. Chem. 34, 3552 (1969); G. L. Bundy et al., Ann. N.Y. Acad. Sci. 180, 76 (1971); and German Pat. No. 2,154,309, Derwent Farmdoc No. 31279T.
13,14-Dihydro-PGE 1 is represented by the formula: ##SPC7##
and the 13,14-dihydro-PGE 1 analogs are represented similarly to the PGE 2 analogs above except that cis--CH=CH-- in the carboxy acid side chain and trans--CH=CH-- in the alkyl-terminated side chain of formulas II, III, and IV are replaced by --CH 2 CH 2 --. These 13,14-dihydro-PGE 1 compounds are available or are prepared by methods known in the art. See for example U.S. Pat. Nos. 3,711,528, 3,728,382, 3,776,938; and German Pat. No. 2,154,309, Derwent Farmdoc No. 31279T.
All of the above prostaglandin-type compounds are known to be useful for a variety of pharmacological and medical purposes, and the esters of this invention are useful for the same purposes.
Esters of the above compounds are known, wherein the hydrogen atom of the carboxyl group is replaced by a hydrocarbyl or substituted hydrocarbyl group. Among these are the methyl ester of PGE 2 (B. Samuelsson, J. Biol. Chem. 238, 3229 (1963)), the methyl ester of 15-methyl-PGE 2 (E. W. Yankee et al., J. Am. Chem. Soc. 94, 3651 (1972)), the methyl ester of 13,14-dihydro-PGE 1 (U.S. Pat. No. 3,598,858), the decyl ester of PGE 2 (Belgian Pat. No. 765,732, Derwent Farmdoc No. 67580S), the 2-phenoxyethyl ester of PGE 2 (Belgian Pat. No. 776,294, Derwent Farmdoc No. 39011T), the phenyl and alkyl-phenyl esters of PGE 2 (British Spec. 1,282,661, Derwent Farmdoc No. 67438R), the p-(1,1-3,3-tetramethyl-butyl)-phenyl ester of PGE 2 , the α (and β-)-naphthyl ester of PGE 2 , and the 5,6,7,8-tetrahydro-2-naphthyl ester of PGE 2 (Belgian Pat. No. 775,106, Derwent Farmdoc No. 33705T) the methyl ester of 16,16-dimethyl-PGE 2 (German Pat. No. 2,217,044, Derwent 71483T), and the methyl and phenyl esters of 17-phenyl-18,19,20-trinor-PGE 2 (German Pat. No. 2,154,309, Derwent 31279T).
SUMMARY OF THE INVENTION
It is a purpose of this invention to provide novel ester derivatives of PGE 2 , PGE 1 , and 13,14-dihydro-PGE 1 and their 15-methyl, 16-(or 16,16-di)methyl, and phenyl-substituted analogs, including the respective 15(R) epimers. It is a further purpose to provide such esters in a free-flowing crystalline form. It is still a further purpose to provide novel processes for preparing these esters.
The presently described phenacyl-type esters include compounds represented by the generic formula: ##EQU9## wherein M is ##EQU10## wherein R 3 is hydrogen or methyl; wherein Q is ##EQU11## wherein each of R 4 and R 5 is hydrogen or methyl, being the same or different, or ##SPC8##
wherein the moiety C t H 2t - represents a valence bond or alkylene of one to 10 carbon atoms, inclusive, with one to 7 carbon atoms, inclusive, between ##EQU12## and the phenyl ring; wherein R 1 is phenyl, p-bromophenyl, p-biphenylyl, p-nitrophenyl, p-benzamidophenyl, or 2-naphthyl; wherein R 2 is hydrogen or benzoyl; and wherein (a) X is --CH 2 CH 2 - or trans-CH=CH- and Y is --CH 2 CH 2 -, or (b) X is trans-CH=CH- and Y is cis-CH=CH-.
Thus, in the presently described esters, the group ##EQU13## is exemplified by: ##EQU14##
For example, PGE 2 , phenacyl ester, is represented by formula VI when M is ##EQU15## X is trans--CH=CH-, Y is cis--CH=CH-, and ##EQU16## is A, i.e. ##EQU17## and is conveniently identified herein as the PGE 2 ester of formula VI-A. Racemic compounds are designated by the prefix "racemic" or "dl"; when that prefix is absent, the intent is to designate an optically active compound. For example, racemic 15-methyl-PGE 1 , p-benzamidophenacyl ester, corresponds to formula VI wherein M is ##EQU18## X is trans--CH=CH-, Y is --CH 2 CH 2 -, and ##EQU19## is E, i.e. ##EQU20## including of course not only the optically active isomer represented by formula VI but also its mirror image.
The novel formula-VI compounds and corresponding racemic compound of this invention are each useful for the same purposes as described above for PGE 2 and are used for those purposes in the same manner known in the art, including oral, sublingual, buccal, rectal, intravaginal, intrauterine, or topical administration.
For many applications these novel prostaglandin esters which I have obtained from certain specified phenacyl-type halides have advantages over the corresponding known prostaglandin compounds. Thus, these phenacyl-type esters are surprisingly stable compounds having outstanding shelf-life and thermal stability. In contrast to the acid form of these prostaglandins, these esters are not subject to acidcatalyzed decomposition by elimination of water or by epimerization. Thus these compounds have improved stability either in solid, liquid, or solution form. In oral administration these esters have shown surprisingly greater efficacy then the corresponding free acids or lower alkyl esters, whether because of longer duration of biological activity or because of improved lipophilicity and absorption is not certain. These esters offer a further advantage in that they have low solubility in water and the body fluids and are therefore retained longer at the site of administration.
A particularly outstanding advantage of many of these phenacyl-type esters is that they are obtained in freeflowing crystalline form, generally of moderately high melting point, in the range 50°-130° C. This form is especially desirable for ease of handling, administering, and purifying. These crystals are highly stable, for example showing practically no decomposition at accelerated storage tests, in comparison with liquid alkyl esters or the free acids. This quality is advantageous because the compound does not lose its potency and does not become contaminated with decomposition products.
These crystalline esters also provide a means of purifying PGE 2 , PGE 1 , 13,14-dihydro-PGE 1 , and their 15-methyl, 16-(or 16,16-di)methyl, or phenyl-substituted analogs, including the respective 15(R) epimers, which are first converted to one of these esters, crystallized and recrystallized until pure, and then recovered as the free acid. One method of recovering the free acid is by enzymatic hydrolysis of the ester, for example with a lipase. See German Pat. No. 2,242,792, Derwent Farmdoc No. 23047U.
A p-iodophenacyl ester of 15(S)-15-methyl-PGF 2 .sub.α was useful for X-ray crystallographic structure determination, E. W. Yankee et al., J. Am. Chem. Soc. 94, 3651 (1972). Various phenacyl esters have been useful for characterizing aliphatic acids because of their sharp melting points, Shriner and Fuson, "Systematic Identification of Organic Compounds", 3rd Ed., pp. 154-157 (1948).
Especially preferred of the novel compounds of this invention are those compounds which are in free-flowing crystalline form, for example:
phenacyl ester of PGE 2
p-bromophenacyl ester of PGE 2
p-phenylphenacyl ester of PGE 2
p-nitrophenacyl ester of PGE 2
p-benzamidophenacyl ester of PGE 2
p-naphthoylmethyl ester of PGE 2
α-benzoylphenacyl ester of PGE 2
p-phenylphenacyl ester of 15(S)-15-methyl-PGE 2
p-nitrophenacyl ester of 15(S)-15-methyl-PGE 2
p-nitrophenacyl ester of 17-phenyl-18,19,20-trinor-PGE 2
p-phenylphenacyl ester of PGE 1
p-phenylphenacyl ester of 16,16-dimethyl-PGE 1
p-phenylphenacyl ester of 17-phenyl-PGE 1
p-phenylphenacyl ester of 13,14-dihydro-18,19,20-trinor-PGE 1
The phenacyl-type esters of PGE 2 , PGE 1 , 13,14-dihydro-PGE 1 and their 15-methyl, 16-(or 16,16-di)methyl, or phenylsubstituted analogs, including the respective 15(R) epimers encompassed by formula VI wherein ##EQU21## is defined by ester groups A through G are produced by the reactions and procedures described and exemplified hereinafter. For convenience, the prostaglandin or prostaglandin analog is referred to as "the PG compound." The term "phenacyl" is used in a generic sense, including also substituted phenyl and naphthyl derivatives.
Various methods are available for preparing these esters. Thus, by one method, the PG compound is converted to a sodium salt by methods known in the art and reacted with an appropriate phenacyl halide in a solvent.
Preferred, however, is the method of simply mixing the PG compound with a phenacyl halide, preferably the bromide, and a tertiary amine in a solvent and letting the reaction proceed at room temperature (about 20° to 30° C. The course of the reaction is readily followed by sampling the mixture and subjecting the samples to thin layer chromatography, usually being complete within 0.25-4.0 hr. Thereafter the reaction mixture is worked up to yield the ester following methods described herein or known in the art, for example the product being purified by silica gel chromatography.
Examples of the phenacyl-type halides useful for this purpose are: phenacyl bromide, p-bromophenacyl bromide, p-phenylphenacyl bromide, p-nitrophenacyl bromide, p-benzamidophenacyl bromide, 2-bromo-2'-acetonaphthone, and 2 -bromo-1,3-diphenyl-1,3-propanedione. In using these reagents the usual precautions are taken to avoid their lachrymatory effects.
Examples of suitable tertiary amines are triethylamine, diethylmethylamine, diisopropylethylamine, dimethylisobutylamine, and dimethylaniline.
Examples of suitable solvents are acetonitrile, dioxane, and tetrahydrofuran, N,N-dimethylformamide, and dimethylsulfoxide.
The phenacyl halide is preferably used in equivalent amounts or in excess to insure that all of the PG compound is converted to ester. Excess phenacyl halide is separated from the product by methods described herein or known in the art, for example by chromatography.
Solid esters are converted to a free-flowing crystalline form on crystallization from a variety of solvents, including ethyl acetate, tetrahydrofuran, methanol, ethanol, and acetone, by cooling or evaporating a saturated solution of the ester in the solvent or by adding a miscible non-solvent such as diethyl ester, hexane, or water. The crystals are then collected by conventional techniques, e.g. filtration or centrifugation, washed with a small amount of solvent, and dried under reduced pressure. They may be dried in a current of warm nitrogen or argon, or by warming up to about 75° C., taking care not to exceed the melting point. Although the crystals are normally pure enough for many applications, they may be recrystallized by the same general techniques to achieve improved purity after each recrystallization.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention can be more fully understood by the following examples.
All temperatures are in degrees centigrade.
Silica gel chromatography, as used herein, is understood to include chromatography on a column packed with silica gel, elution, collection of fractions, and combination of those fractions shown by thin layer chromatography (TLC) to contain the desired product free of starting material and impurities.
"TLC," herein, refers to thin layer chromatography.
EXAMPLE 1
PGE 2 , Phenacyl Ester (Formula VI-A wherein M is ##EQU22## Q is n-pentyl, X is trans-CH=CH--, and Y is cis-CH=CH--.
A mixture of PGE 2 (0.50 g.), phenacyl bromide (0.440 g.) and 0.37 ml. of diisopropylethylamine in 10 ml. of acetonitrile is left standing for one hour at about 25° C. The mixture is diluted with 200 ml. of ethyl acetate and extracted with aqueous 0.1 N. phosphate buffer at pH 7.5 and then water. The organic phase is dried over sodium sulfate and concentrated under reduced pressure to a crude residue. The residue is subjected to silica gel chromatography, eluting with ethyl acetate-hexane (1:1) followed by ethyl acetate. The residue obtained by concentration of selected fractions is crystallized from ethyl acetate-hexane as the title compound, white free-flowing crystals, 0.510 g., m.p. 57.3°-58.8°, having R f 0.65 (TLC on silica gel in ethyl acetate).
EXAMPLE 2
PGE 2 , p-Bromophenacyl Ester (Formula VI-B wherein M is ##EQU23## Q is n-pentyl, X is trans-CH=CH-, and Y is cis-CH=CH-).
Following the procedure of Example 1 but using 0.50 g. of PGE 2 , 0.80 g. of p-bromophenacyl bromide, and 0.37 ml. of diisopropylethylamine in 10 ml. acetonitrile and kept for 2 hrs. at about 25° C., there is obtained a crude residue. This residue is subjected to silica gel chromatography, eluting with ethyl-acetate-hexane (1:1) followed by ethylacetate. The residue obtained by concentration of selected fractions is crystallized from ethyl acetate-hexane as the title compound, white free-flowing crystals, 0.628 g., m.p. 83.3°-87.5° C., having R f 0.4 (TLC on silica gel in ethylacetate-hexane (7:3)).
EXAMPLE 3
PGE 2 , p-Phenylphenacyl Ester (Formula VI-C wherein M is ##EQU24## Q is n-pentyl, X is trans-CH=CH-, and Y is cis-CH=CH-).
Following the procedure of Example 1 but using 0.242 g. of PGE 2 , 0.720 g. of p-phenylphenacyl bromide, and 0.40 ml. of diisopropylethylamine, there is obtained a crude residue. This residue is subjected to silica gel chromatography, eluting with 100 ml. of ethyl acetate-hexane (1:3) followed by 100 ml. of ethyl acetate-hexane (1:1), 200 ml. of ethyl acetate and finally 200 ml. of ethyl acetate-acetone (3:2). The residue obtained by concentration of selected fractions is crystallized from ethyl acetate-hexane as the title compound, white free-flowing crystals, 0.328 g., m.p. 98.6°-100.9°, having R f 0.4 (TLC on silica gel in ethyl acetate-hexane (4:1)).
EXAMPLE 4
PGE 2 p-Nitrophenacyl Ester (Formula VI-D wherein M is ##EQU25## O is n-pentyl, X is trans-CH=CH-, and Y is cis-CH=CH-).
Following the procedure of Example 1 but using 0.100 g. of PGE 2 , 0.100 g. p-nitrophenacyl bromide, and 0.100 ml. of diisopropylethylamine in 10 ml. of acetonitrile for 15 min. at about 25° C., there is obtained a crude residue. This residue is subjected to silica gel chromatography, eluting with chloroform-acetonitrile (9:1). The residue obtained by concentration of selected fractions is crystallized from ethyl acetate-hexane as the title compound, white free-flowing crystals, 0.088 g., m.p. 65.9°-67.2° C., having R f 0.7 (TLC on silica gel in chloroform-acetonitrile (1:1)).
EXAMPLE 5
PGE 2 , p-Benzamidophenacyl Ester (Formula VI-E wherein M is ##EQU26## Q is n-pentyl, X is trans--CH=CH-, and Y is cis-CH=CH-).
Following the procedure of Example 1 but using 0.352 g. of PGE 2 , 0.410 g. of p-benzamidophenacyl bromide, and 1.0 ml. of diisopropylethylamine in 20 ml. of acetonitrile held for 2 hr. at about 25° C., there is obtained crude residue. This residue is subjected to silica gel chromatography, eluting with ethyl acetate-hexane (7:3) followed by tetrahydrofuran. The residue obtained by concentration of selected fractions is crystallized from hot ethanol-water (1:1) as the title compound, white free-flowing crystals, 0.39 g., m.p. 125.8°-129.0° C., having R f 0.42 (TLC on silica gel in ethyl acetate-acetic acid (97:3)).
Example 6
PGE 2 , 2-Naphthoylmethyl Ester (Formula VI-F wherein M is ##EQU27## Q is n-pentyl, X is trans-CH=CH-, and Y is cis-CH=CH-).
Following the procedure of Example 1 but using 0.500 g. of PGE 2 , 0.80 g. of 2-bromo-2'-acetonaphthone, and 0.37 ml. of diisopropylethylamine in 10 ml. of acetonitrile kept for 2 hr. at about 25° C., there is obtained a crude residue. This residue is subjected to silica gel chromatography, eluting with ethyl acetate-hexane (1:1) followed by ethyl acetate. The residue obtained by concentration of selected fractions is crystallized from ethyl acetate-hexane, as the title compound, white free-flowing crystals, 0.658 g., m.p. 64.8°-66.3°C., having R f 0.4 (TLC on silica gel in ethyl acetate-hexane (7:3)).
EXAMPLE 7
PGE 2 , α-Benzoylphenacyl Ester (Formula VI-G wherein M is ##EQU28## Q is n-pentyl, X is trans-CH=CH-, and Y is cis-CH=CH-).
Following the procedure of Example 1 but using 0.352 g. of PGE 2 , 0.306 g. of 2-bromo-1,3-diphenyl-1,3 -propanedione, and 0.129 g. of diisopropylethylamine, there is obtained a crude residue. This residue is subjected to silica gel chromatography, eluting with chloroform-acetonitrile (9:1). The residue obtained by concentration of selected fractions is crystallized from ethyl acetate-hexane as the title compound, white free-flowing crystals, 0.165 g., m.p. 103.8°- 106.5° C., having R f 0.5 (TLC on silica gel in chloroformacetonitrile (7:3)).
EXAMPLE 8
15(S)-15-Methyl-PGE 2 , p-Phenylphenacyl Ester (Formula VI-C wherein M is ##EQU29## Q is n-pentyl, X is trans-CH=CH-, and Y is cis-CH=CH-).
Following the procedure of Example 1 but using 0.163 g. of 15-methyl-PGE 2 , 0.611 g. of p-phenylphenacyl bromide, and 0.154 ml. of diisopropylethylamine in 12 ml. of acetonitrile, held for 1 hr. at about 25° C., there is obtained a crude residue. This residue is subjected to silica gel chromatography, eluting with ethyl acetate. The residue obtained by concentration of selected fractions is crystallized from ethyl acetate-hexane as the title compound, white free-flowing crystals, 0.153 g., m.p. 90.3°-91.3° C., having R f 0.7 (TLC on silica gel in ethyl acetate-acetic acid (97:3)).
EXAMPLE 9
15(S)-15-Methyl-PGE 2 , p-Nitrophenacyl Ester (Formula VI-D wherein M is ##EQU30## Q is n-pentyl, X is trans-CH=CH-, and Y is cis-CH=CH-).
Following the procedure of Example 1 but using 0.163 g. of 15-methyl-PGE 2 , 0.543 g. of p-nitrophenacyl bromide, and 0.154 ml. of diisopropylethylamine in 10 ml. of acetonitrile, held for one hour at about 25° C., there is obtained a crude residue. This residue is subjected to silica gel chromatography, eluting with ethyl acetate-chloroform (1:1) followed by ethyl acetate-acetone (4:1). The residue obtained by concentration of selected fractions, an oil, is further purified on a preparative TLC silica gel plate, eluting with acetone-methanol (4:1). There is obtained the title compound, a pale-yellow free-flowing crystalline solid, 0.117 g., m.p. 115.8°-118.8° C., having R f 0.6 (TLC on silica gel in ethyl acetate).
EXAMPLE 10
15(R)-15-Methyl-PGE 2 , p-Nitrophenacyl Ester (Formula VI-D wherein M is ##EQU31## Q is n-pentyl, X is trans-CH=CH- and Y is cis-CH=CH-).
Following the procedure of Example 1 but using 0.205 g. of 15(R)-15-Methyl-PGE 2 , 0.274 g. of p-nitrophenacyl bromide and 0.145 ml. of diisopropylethylamine, there is obtained a crude, viscous, brown residue. This residue is subjected to silica gel chromatography, eluting with chloroform-acetonitrile (1:1). The residue obtained by concentration of selected fractions, colorless liquid, 0.290 g. is the title compound, a colorless liquid, 0.290 g., having R f 0.5 (TLC on silica gel in chloroform-acetonitrile (1:2)).
EXAMPLE 11
16,16-Dimethyl-PGE 2 , Phenacyl Ester (Formula VI-A wherein M is ##EQU32## Q is ##EQU33## X is trans-CH=CH-, and Y is cis-CH=CH-).
Following the procedure of Example 1 but using 0.190 g. of 16,16-dimethyl-PGE 2 , 0.099 g. of α-bromoacetophenone, and 0.065 g. of diisopropylethylamine in 15 ml. of acetonitrile, stirred for one hour at about 25° C., there is obtained a crude residue. This residue is dissolved in 20 ml. of acetonitrile, mixed with 100 ml. of 0.1 N. citric acid buffer at pH 2.5, and extracted with 100 ml. of ethyl acetate. The organic phase is dried and concentrated to yield the title compound, a light yellow gum, having mass spectral peaks at 627, 552, 543, 537, 453, 399, 227, 105, and 77, and having R f 0.64 (TLC on silica gel in ethyl acetate-acetic acid (97:3)).
EXAMPLE 12
16,16-Dimethyl-PGE 2 , p-Phenylphenacyl Ester (Formula VI-C wherein M is ##EQU34## Q is ##EQU35## X is trans-CH=CH-, and Y is cis-CH=CH-).
Following the procedure of Example 1 but using 0.190 g. of 16,16-dimethyl-PGE 2 , 0.550 g. of 2-bromo-4'-phenylacetophenone, and 0.297 g. of diisopropylamine in 15 ml. of acetonitrile, stirred for one hour at about 25°C., there is obtained a crude residue. This residue is subjected to silica gel chromatography, eluting with hexane followed by ethyl acetatehexane 1:1. The residue obtained by concentration of selected fractions is the title compound, a light yellow gum, having mass spectral peaks at 619, 529, 497, 475, 407, and 181, and having R f 0.73 (TLC on silica gel in ethyl acetate-acetic acid (97:3)).
EXAMPLE 13
17-Phenyl-18,19,20-trinor-PGE 2 , p-Nitrophenacyl Ester (Formula VI-D wherein M is ##EQU36## Q is ##SPC9##
X is trans-CH=CH-, and Y is cis-CH=CH-).
Following the procedure of Example 1 but using 0.210 g. of 17-phenyl-18,19,20-trinor-PGE 2 , 0.275 g. p-nitrophenacyl bromide, and 0.146 ml. of diisopropylethylamine, there is obtained a crude, light brown, viscous residue. This residue is subjected to silica gel chromatography, eluting with chloroform-acetonitrile (1:1). The residue obtained by concentration of selected fractions is a colorless semisolid, which is crystallized from 5 ml. ethylacetate by dilution with 5 ml. hexane to yield the title compound, white free-flowing crystals, 0.250 g., m.p. 74.7°-76.5° C., naving R f 0.45 (TLC on silica gel in chloroform-acetonitrile (1:1)).
EXAMPLE 14
PGE 1 , p-Phenylphenacyl Ester (Formula VI-C wherein M is ##EQU37## Q is n-pentyl, X is trans-CH=CH-, and Y is -CH 2 CH 2 -).
A mixture of PGE 1 (0.555 g.), p-phenylphenacyl bromide (0.731 g.) and 0.34 ml. of diisopropylethylamine in 10 ml. of acetonitrile is shaken until completely miscible, then left standing one hour at about 25° C. The mixture is concentrated under reduced pressure to a crude residue and subjected to silica gel chromatography, eluting with ethyl acetate and then with acetonitrile. The residue obtained by concentration of selected fractions, 0.682 g., is recrystallized from ethyl acetate-hexane as the title compound, white free-flowing crystals 0.668 g., m.p. 112.2°- 113.2° C., having R f 0.7 (TLC on silica gel in ethyl acetate).
EXAMPLE 15
16,16-Dimethyl-PGE 1 , p-Phenylphenacyl Ester (Formula VI-C wherein M is ##EQU38## Q is ##EQU39## X is trans-CH=CH-, and Y is -CH 2 CH 2 -).
Following the procedure of Example 14 but using 0.30 g. fo 16,16-dimethyl-PGE 1 , 0.75 g. of p-phenylphenacyl bromide, and 0.5 ml. of diisopropylethylamine in 12 ml. of acetonitrile, there is obtained a crude residue. This residue is subjected to silica gel chromatography, eluting with 33 to 60 percent ethyl acetate in Skellysolve B. The residue obtained by concentration of selected fractions, is crystallized from ethyl ether-Skellysolve B as the title compound, 0.175 g., free-flowing crystals, m.p. 77-8° C., having NMR peaks at 7.3-8.1, 5.66, 5.36, 3.25-4.3, 0.9, and 0.85 δ, and having R f 0.60 (TLC on silica gel in ethyl acetate).
EXAMPLE 16
17-Phenyl-18,19,20-trinor-PGE 1 , p-Phenylphenacyl Ester (Formula VI-C wherein M is ##EQU40## Q is ##SPC10##
X is trans-CH=CH-, and Y is -CH 2 CH 2 -).
Following the procedure of Example 14 but using 0.20 g. of 17-phenyl-18,19,20-trinor-PGE 1 , 0.6 g. of p-phenylphenacyl bromide, and 0.4 ml. of diisopropylethylamine in 10 ml. of acetonitrile, there is obtained a crude solid residue. This residue is subjected to silica gel chromatography, eluting with 30-100 percent ethyl acetate in Skellysolve B. The residue obtained by concentration of selected fractions, 0.277 g., partially crystalline, is recrystallized from acetone-Skellysolve B as the title compound, 0.18 g., white free-flowing needles, m.p. 112°-113° C., having R f 0.53 (TLC on silica gel in ethyl acetate) and infrared absorption bonds at 3360, 1745, 1715, 1685, 1600, 1240, 1165, 1125, 1095, 1075, 1005, 970, 765, 750, 700, and 695 cm - 1 .
EXAMPLE 17
13,14-Dihydro-PGE 1 , p-Phenylphenacyl Ester (Formula VI-C wherein M is ##EQU41## Q is n-pentyl, and X and Y are --CH 2 CH 2 -).
Following the procedure of Example 14 but using 2.7 g. of 13,14-dihydro-PGE 1 , 5.0 g. of p-phenylphenacyl bromide, and 4.5 ml. of diisopropylethylamine in 110 ml. of acetonitrile, there is obtained a crude residue. This residue is subjected to silica gel chromatography, eluting with 40-75 percent ethyl acetate in Skellysolve B. The residue obtained by concentration of selected fractions, 3.2 g. is crystallized from ethyl acetate-Skellysolve B (1:3) as the title compound, 2.63 g., white free-flowing crystals, m.p. 89°-91° C., having infrared absorption bands at 3420, 1745, 1725, 1690, 1605, 1580, 1555, 1485, 1340, 1235, and 1165.
Following the procedures of Examples 1-17 but employing the racemic forms of the PG compounds, there are obtained the corresponding esters of racemic PG compounds.
EXAMPLES 18-112
The phenacyl-type esters of PGE 2 , PGE 1 , 13,14-dihydro-PGE 1 , and their 15-methyl, 16-(or 16,16-di)methyl, or phenylsubstituted analogs, including the respective 15(R) epimers of Tables I-XV below are obtained following the procedures of Example 1, wherein the prostaglandin compound is reacted in the presence of diisopropylethylamine with the appropriate phenacyl halide reagent listed in the Table. The crude products, obtained by concentration under reduced pressure, are purified by means described herein or known in the art, including partitioning, solvent extraction, washing, silica gel chromatography, trituration, or crystallization.
Following the procedures of Examples 18-112 but employing the racemic forms of the PG compounds, there are obtained the corresponding esters of the racemic PG compounds.
Likewise following the procedures of Examples 61-112 but employing the 15(R) forms of the PG compounds and their racemic forms, there are obtained the corresponding esters of the respective 15(R) PG compounds and their forms.
TABLE 1______________________________________Esters of 15(R)-PGE.sub.2Refer to formula VI wherein ∠ M is HOH, Q is n-pentyl, X is trans-CH=CH-- and Y is cis-CH=CH--. Product 15(R)-PGE.sub.2Example Phenacyl Halide ester of formula:______________________________________18 phenacyl bromide VI-A19 p-bromophenacyl bromide VI-B20 p-phenylphenacyl bromide VI-C21 p-nitrophenacyl bromide VI-D22 p-benzamicophenacyl bromide VI-E23 2-bromo-2'-acetonaphthone VI-F24 2-bromo-1,3-diphenyl-1,3- VI-G propanecione______________________________________
TABLE II______________________________________Esters of 15(S)-15-Methyl-PGE.sub.2Refer to formula VI wherein ∠ M is CH.sub.3 OH, Q is n-pentyl, X is trans-CH=CH--, and Y is cis-CH=CH--.) Product 15(S)-15- Methyl-PGE.sub.2 esterExample Phenacyl Halide of formula:______________________________________25 phenacyl bromide VI-A26 p-bromophenacyl bromide VI-B27 p-benzamidophenacyl bromide VI-E28 2-bromo-2'-acetonaphthone VI-F29 2-bromo-1,3-diphenyl-1,3- VI-G propanedione______________________________________
TABLE III______________________________________Esters of 15(R)-15-Methyl-PGE.sub.2Refer to formula VI wherein ∠ M is CH.sub.3 OH, Q is n-pentyl, X is trans-CH=CH--, and Y is cis-CH=CH--.) Product 15(R)-15- methyl-PGE.sub.2 esterExample Phenacyl Halide of formula:______________________________________30 phenacyl bromide VI-A31 p-bromophenacyl bromide VI-B32 p-phenylphenacyl bromide VI-C33 p-benzamidophenacyl bromide VI-E34 2-bromo-2'-acetonaphthone VI-F35 2-bromo-1,3-diphenyl-1,3- VI-G propanedione______________________________________
TABLE IV______________________________________Esters of 16,16-dimethyl-PGE.sub.2Refer to formula VI wherein ∠ M is OH, Q is --C(CH.sub.3).sub.2 --(CH.sub.2).sub.3 --CH.sub.3, X is trans-CH=CH--, and Y is cis-CH=CH--.) Product 16,16-di- methyl PGE.sub.2 esterExample Phenacyl Halide of formula:______________________________________36 p-bromophenacyl bromide VI-B37 p-nitrophenacyl bromide VI-D38 p-benzamidophenacyl bromide VI-E39 2-bromo-2'-acetonaphthone VI-F40 2-bromo-1,3-diphenyl-1,3- VI-G propanedione______________________________________
TABLE V______________________________________Esters of 15(R)-16,16-dimethyl-PGE.sub.2Refer to formula VI wherein ∠ M is HOH, Q is --C(CH.sub.3).sub.2 --(CH.sub.2).sub.3 --CH.sub.3, X is trans-CH=CH--, and Y is cis-CH=CH--.) Product 15(R)-16,16- 16-dimethyl-PGE.sub.2Example Phenacyl Halide ester of formula:______________________________________41 phenacyl bromide VI-A42 p-bromophenacyl bromide VI-B43 p-phenylphenacyl bromide VI-C44 p-nitrophenacyl bromide VI-D45 p-benzamidophenacyl bromide VI-E46 2-bromo-2'-acetonaphthone VI-F47 2-bromo-1,3-diphenyl-1,3- VI-G propanedione______________________________________
TABLE VI______________________________________Esters of 17-Phenyl-18,19,20-trinor-PGE.sub.2Refer to formula VI wherein ∠ M is HOH, Q is X is trans-CH=CH--, and Y is cis-CH=CH--.) Product 17-phenyl- 18,19,20-trinor-Example Phenacyl Halide PGE.sub.2 ester of formula:______________________________________48 Phenacyl bromide VI-A49 p-bromophenacyl bromide VI-B50 p-phenylphenacyl bromide VI-C51 p-benzamidophenacyl bromide VI-E52 2-bromo-2'-acetonaphthone VI-F53 2-bromo-1,3-diphenyl-1,3- VI-G propanedione______________________________________
TABLE VII______________________________________Esters of 15(R)-17-Phenyl-18,19,20-trinor-PGE.sub.2(Refer to formula VI wherein ∠ M is HOH, Q is X is trans-CH=CH--, and Y is cis-CH=CH--.) Product 15(R)- 17-phenyl-18,19,20- trinor-PGE.sub.2 esterExample Phenacyl Halide of formula:______________________________________54 phenacyl bromide VI-A55 p-bromophenacyl bromide VI-B56 p-phenylphenacyl bromide VI-C57 p-nitrophenacyl bromide VI-D58 p-benzamidophenyl bromide VI-E59 2-bromo-2'-acetonaphthone VI-F60 2-bromo-1,3-diphenyl-1,3- VI-G propanedione______________________________________
TABLE VIII______________________________________Esters of PGE.sub.1Refer to formula VI wherein ∠ M is HOH. Q is n-pentyl, X is trans-CH=CH--, and Y is --CH.sub.2 CH.sub.2 --.) Product PGE.sub.1Example Phenacyl Halide ester of formula:______________________________________61 phenacyl bromide VI-A62 p-bromophenacyl bromide VI-B63 p-nitrophenacyl bromide VI-D64 p-benzamidophenacyl bromide VI-E65 2-bromo-2'-acetonaphthone VI-F66 2-bromo-1,3-diphenyl-1,3- VI-G propanedione______________________________________
TABLE IX______________________________________Esters of 15(S)-15-Methyl-PGE.sub.1Refer to formula VI wherein ∠ M is CH.sub.3 OH, Q is n-pentyl, X is trans-CH=CH-- and Y is --CH.sub.2 CH.sub.2 --.) Product 15(S)-15-methyl-Example Phenacyl Halide PGE.sub.1 ester of formula:______________________________________67 phenacyl bromide VI-A68 p-bromophenacyl bromide VI-B69 p-phenylphenacyl bromide VI-C70 p-nitrophenacyl bromide VI-D71 p-benzamidophenacyl bromide VI-E72 2-bromo-2'-acetonaphthone VI-F73 2-bromo-1,3-diphenyl- VI-G 1,3-propanedione______________________________________
TABLE X______________________________________Esters of 16,16-Dimethyl-PGE.sub.1Refer to formula VI wherein ∠ M is HOH Q is --C(CH.sub.3).sub.2 --(CH.sub.2).sub.3 --CH.sub.3, X is trans-CH=CH--, and Y is --CH.sub.2 CH.sub.2 --.) Product of 16,16-di- methyl-PGE.sub.1 esterExample Phenacyl Halide of formula:______________________________________74 phenacyl bromide VI-A75 p-bromophenacyl bromide VI-B76 p-nitrophenacyl bromide VI-D77 p-benzamidophenacyl bromide VI-E78 2-bromo-2'-acetonaphthone VI-F79 2-bromo-1,3-diphenyl- VI-G 1,3-propanedione______________________________________
TABLE XI______________________________________Esters of 17-Phenyl-18,19,20-trinor-PGE.sub.1Refer to formula VI wherein ∠ M is HOH, Q is X is trans-CH=CH--, and Y is --CH.sub.2 CH.sub.2 --, Product 17-phenyl- 18,19,20-trinor-PGE.sub.1Example Phenacyl Halide ester of formula:______________________________________80 phenacyl bromide VI-A81 p-bromophenacyl bromide VI-B82 p-nitrophenacyl bromide VI-D83 p-benzamidophenacyl bromide VI-E84 2-bromo-2'-acetonaphthone VI-F85 2-bromo-1,3-diphenyl- VI-G 1,3-propanedione______________________________________
TABLE XII______________________________________Esters of 13, 14-Dihydro-PGE.sub.1Refer to formula VI wherein ∠ M is HOH, Q is n-pentyl, and X and Y are --CH.sub.2 CH.sub.2 --.) Product 13,14-di- hydro-PGE.sub.1 esterExample Phenacyl Halide of formula:______________________________________86 phenacyl bromide VI-A87 p-bromophenacyl bromide VI-B88 p-nitrophenacyl bromide VI-D89 p-benzamidophenacyl bromide VI-E90 2-bromo-2'-acetonaphthone VI-F91 2-bromo-1,3-diphenyl-1,3- VI-G propanedione______________________________________
TABLE XIII______________________________________Esters of 15(S)-15-Methyl-13,14-Dihydro-PGE.sub.1(Refer to formula VI wherein ∠ M is CH.sub.3 OH, Q is n-pentyl, and X and Y are --CH.sub.2 CH.sub.2 --.) Product 15(S)-15-methyl- 13,14-dihydro-PGE.sub.1Example Phenacyl Halide ester of formula:______________________________________92 phenacyl bromide VI-A93 p-bromophenacyl bromide VI-B94 p-phenylphenacyl bromide VI-C95 p-nitrophenacyl bromide VI-D96 p-benzamidophenacyl bromide VI-E97 2-bromo-2'-acetonaphthone VI-F98 2-bromo-1,3-diphenyl-1,3- VI-G propanedione______________________________________
TABLE XIV______________________________________Esters of 16,16-Dimethyl-13,14-dihydro-PGE.sub.1Refer to formula VI wherein ∠ M is HOH, Q Is --C(CH.sub.3).sub.2 --(CH.sub.2).sub.3 --CH.sub.3, and X and Y are --CH.sub.2 CH.sub.2 --.) Product 16,16-di- methyl-13,14-dihydro-Example Phenacyl Halide PGE.sub.1 ester of formula:______________________________________ 99 phenacyl bromide VI-A100 p-bromophenacyl bromide VI-B101 p-phenylphenacyl bromide VI-C102 p-nitrophenacyl bromide VI-D103 p-benzamidophenacyl bromide VI-E104 2-bromo-2'-acetonaphthone VI-F105 2-bromo-1,3-diphenyl- VI-G 1,3-propanedione______________________________________
TABLE XV______________________________________Esters of 13,14-dihydro-13-phenyl-18,19,20-trinor-PGE.sub.1Refer to formula VI wherein ∠ M is HOH, Q is X and Y are --CH.sub.2 CH.sub.2 --.) Product 13,14- dihydro-17-phenyl- 18,19,20-trinor-PGE.sub.1Example Phenacyl Halide ester of formula:______________________________________106 phenacyl bromide VI-A107 p-bromophenacyl bromide VI-B108 p-phenylphenacyl bromide VI-C109 p-nitrophenacyl bromide VI-D110 p-benzamidophenacyl bromide VI-E111 2-bromo-2'-acetonaphthone VI-F112 2-bromo-1,3-diphenyl- VI-G 1,3-propanedione______________________________________
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Phenacyl-type esters of PGE 2 , PGE 1 , and 13,14-dihydro-PGE 1 and their 15-methyl, 16,16-dimethyl, and 17-phenyl analogs, including the respective 15(R)epimers, are disclosed, represented by the formula ##EQU1## wherein M is ##EQU2## wherein R 3 is hydrogen or methyl; wherein Q is ##EQU3## wherein each of R 4 and R 5 is hydrogen or methyl, being the same or different, or ##SPC1##
Wherein the moiety -C t H 2t - represents a valence bond or alkylene of one to 10 carbon atoms, inclusive, with one to 7 carbon atoms, inclusive, between ##EQU4## and the phenyl ring; wherein R 1 is phenyl, p-bromophenyl, p-biphenylyl, p-nitrophenyl, p-benzamidophenyl, or 2-naphthyl; wherein R 2 is hydrogen or benzoyl; and wherein (a) X is --CH 2 CH 2 -- or trans-CH=CH- and Y is -CH 2 CH 2 --, or (b) X is trans-CH=CH- and Y is cis-CH=CH-. The products are useful for the same pharmacological and medical purposes as the corresponding prostaglandins and analogs, and are also useful as a means for obtaining highly purified products.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/353,589 entitled SHUT-OFF TRIM INCLUDING SPRING LOADED CHECK VALVE filed Jun. 10, 2010.
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The present invention relates generally to bi-directional valves for high pressure fluid flow and, more particularly, to a bi-directional shut-off trim for a valve which possesses the functional attributes of a pilot operated trim and a balanced trim through the integration of a spring loaded check valve into a pilot trim. In forward flow isolation, the bi-directional shut-off trim of the present invention acts as a normal pilot operated trim. In reverse flow, the check valve of the shut-off trim opens to balance the pressure on either side of the plug thereof.
2. Description of the Related Art
There is known in the prior art valve constructions which are adapted to provide pressure balance on opposite sides of a main valve assembly during both opening and closing movements of the main valve assembly with fluid flow in either direction through the valve. One such exemplary prior art bi-directional balanced valve is disclosed in U.S. Pat. No. 3,888,280 entitled BI-DIRECTIONAL PRESSURE BALANCED VALVE issued Jun. 10, 1975.
However, currently known valve constructions or designs providing a bi-directional pressure balanced function are often subject to early failure and malfunctioning when used under severe service conditions, e.g., under high temperature and high pressure operating conditions. More particularly, the failure or malfunctioning of currently known valve designs is often attributable to the rapid erosion of deterioration of their sealing areas, as well as other critical valve components. In this regard, the available seal materials usable in conjunction with currently known bi-directional pressure balanced valve designs are often not adequate for providing required shut-off characteristics, and further frequently make the valve susceptible to early failure when the such seal materials are subjected or exposed to the intended operational environment of the valve.
The present invention is intended to represent an improvement to existing bi-directional pressure balanced valve designs by providing a valve shut-off trim which combines a pilot operated trim and a balanced trim through the addition of a spring loaded check valve within the pilot trim. As indicated above, in forward flow isolation, the shut-off trim of the present invention acts as a normal pilot operated trim, while in reverse flow, the check valve thereof opens to balance the pressure on either side of the plug of the trim. Thus, the addition of the spring loaded check valve in the shut-off trim of the present invention causes the pilot operated trim to act as a balanced plug in the reverse flow direction. These, as well as other features and advantages of the present invention, will be described in more detail below.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a valve shut-off trim which includes a spring loaded check valve and is usable in applications requiring valves with bi-directional shut-off trim where the use of unbalanced trim designs is not feasible and the choice of seals is limited by temperature, and/or radiation, and/or chemistry of seal materials. The shut-off trim constructed in accordance with the present invention finds particular utility in applications requiring shut-off in a forward direction of Class V and shut-off in a reverse flow direction of Class IV, with forward flow being, for example, water at 440° F. and reverse flow being, for example, steam at 567° F.
In the present invention, to obtain Class IV shut-off in a reverse flow direction, carbon piston rings are integrated into the shut-off trim. By combining a pilot ported plug and a check valve (which allows flow in the reverse direction), the shut-off trim of the present invention allows isolation in forward and reverse directions. In the forward direction, the trim achieves leak-tight shut-off (pilot ported plug acts an unbalanced plug when in the closed position). In the reverse direction and during modulation, the shut-off trim acts as a balanced plug. Thus, when reverse pressure unseats the pilot plug, the trim acts a balanced plug as indicated above. The shut-off trim of the present invention preferably includes a spring for loading the pilot plug.
Due to its construction, which will be described with particularity below, the shut-off trim constructed in accordance with the present invention eliminates reliance on elastomeric balance seals for the forward flow direction, and allows for the use of, by way of example, carbon or metallic piston rings for the reverse direction shut-off requirements. Thus, the shut-off trim of the present invention eliminates the need for a lengthy seal qualification program and extends the qualified life of the equipment in the field with integrates the same. As a result, the shut-off trim constructed in accordance with the present invention has the capability of satisfying safety related isolation functions that have been imposed on control valves integrated or used in certain applications, such as those requiring the aforementioned Class V shut-off in a forward direction and a Class IV shut-off in a reverse direction. In many of these applications, the use of graphoil seals would not be suitable due to the number of open/close/small modulation cycles that are imposed by the application requirements. Additionally, elastomeric seals are generally unsuitable for obtaining Class V shut-off since this requirement often pushes such elastomeric seals to or beyond their documented usable limits, or undesirably shortens their qualified life due to, for example, the limited ability thereof to withstand radiation, as well as their susceptibility to hardening due to thermal aging.
The present invention is best understood in reference to the following detailed description when read in conjunction with accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
These, as well as other features of the present invention, will become more apparent upon reference to the drawings wherein:
FIG. 1 is a side-elevational, partial cross-sectional view of a shut-off trim constructed in accordance with a first embodiment of the present invention;
FIG. 2 is a side-elevational, partial cross-sectional view of a shut-off trim constructed in accordance with a second embodiment of the present invention;
FIGS. 3A-3C are side-elevational views illustrating a plug sleeve of the shut-off trim shown in FIG. 2 in differing states of actuation;
FIG. 3D is a cross-sectional view of the plug sleeve of the shut-off trim shown in FIGS. 2 and 3 A- 3 C;
FIGS. 4A-4C are side-elevational views illustrating an auxiliary plug in differing states of actuation which may be used as an alternative to the plug sleeve shown in FIGS. 2 and 3 A- 3 D in a shut-off trim constructed in accordance with a third embodiment of the present invention;
FIG. 5 is a side-elevational, partial cross-sectional view of a shut-off trim constructed in accordance with a fourth embodiment of the present invention; and
FIGS. 6A-6B are side-elevational views illustrating the check valve of the shut-off trim shown in FIG. 5 in differing states of actuation.
Common reference numerals are used throughout the drawings and detailed description to indicate like elements.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings wherein the showings are for purposes of illustrating preferred embodiments of the present invention only, and not for purposes of limiting the same, FIG. 1 depicts a shut-off trim 10 constructed in accordance with a first embodiment of the present invention. It is contemplated that the trim 10 will be integrated into a valve construction wherein the valve includes a housing which defines an interior plug chamber 14 . The plug chamber 14 is partially defined by a generally cylindrical, tubular fluid energy dissipation device, such as the disc stack 16 shown in FIG. 1 . The plug chamber 14 is further partially defined by a generally cylindrical, tubular plug sleeve 18 which is coaxially aligned with the disc stack 16 , one end of the plug sleeve 18 typically being engaged to a corresponding end of the disc stack 16 .
In addition to the plug chamber 14 , the housing 12 of the valve into which the trim 10 is integrated also defines an inflow passage 20 and an outflow passage 22 which each fluidly communicate with the plug chamber 14 . The inflow and outflow passages 20 , 22 are more easily seen in those embodiments of the shut-off trim depicted in FIGS. 2 and 5 . In the valve including the trim 10 , fluid traveling through the inflow passage 20 flows radially inwardly through the disc stack 16 and into the plug chamber 14 . When the trim 10 is in an open condition or state as will be described in more detail below, fluid entering the plug chamber 14 is able to flow into the outflow passage 22 , and thereafter exit the valve including the trim 10 . Typically, the interface between the outflow passage 22 and the plug chamber 14 is defined by an annular seat ring 24 .
The trim 10 constructed in accordance with the first embodiment of the present invention comprises a main pilot plug 28 which, from the perspective shown in FIG. 1 , defines a top surface 30 , a bottom surface 32 , a side surface 34 , and a beveled sealing surface 36 which extends between the bottom and side surfaces 32 , 34 . The pilot plug 28 is not solid, but rather has a bore 38 extending axially therethrough. As is also apparent from FIG. 1 , the bore 38 is not of uniform diameter. Rather, the bore 38 defines four (4) different segments or sections, each of which is of a differing diameter. More particularly, the diameters of the bore sections defined by the bore 38 progressively decrease from the top surface 30 to the bottom surface 32 , with the lowermost bore section extending to the bottom surface 32 thus being of the smallest diameter of the four bore sections. The uppermost and upper middle bore sections are separated from each other by an annular shoulder 40 . Similarly, the upper middle and lower middle bore sections are separated by an annular shoulder 42 , with the lower middle and lowermost bore sections being separated by an annular shoulder 44 . Disposed within the shoulder 40 is a plurality of elongate grooves or channels 46 , the use of which will be described in more detail below. Additionally, disposed in the side surface 34 of that portion of the pilot plug 28 which defines the uppermost bore section is a plurality of sealing rings 48 which circumvent the pilot plug 28 and are used for reasons which will also be described in more detail below.
When the trim 10 is in a closed position within the exemplary valve including the same, the sealing surface 36 defined by the pilot plug 28 is firmly seated and sealed against the seat ring 24 . The trim 10 assumes an open position when, from the perspective shown in FIG. 1 , the pilot plug 28 is caused to move upwardly as results in the sealing surface 36 thereof effectively being separated from the seat ring 24 . Such separation allows fluid within the plug chamber 14 to flow between the sealing surface 36 and seat ring 24 into the outflow passage 22 .
In addition to the pilot plug 28 , the trim 10 includes check valve assembly comprising an auxiliary plug 50 which resides within the bore 38 of the pilot plug 28 . Like the pilot plug 28 , the auxiliary plug 50 , when viewed from the perspective shown in FIG. 1 , defines a top surface 52 , a bottom surface 54 , a side surface 56 , and a beveled sealing surface 58 which extends between the bottom and side surfaces 54 , 56 . As is apparent from FIG. 1 , the side surface 56 of the auxiliary plug 50 is not of uniform outer diameter. Rather, the side surface 56 defines four (4) side surface sections or segments which may be of differing outer diameter. Along these lines, it is contemplated that the outer diameter of the lowermost segment of the side surface 56 to which the sealing surface 58 extends will be of the greatest diameter in the auxiliary plug 50 . In the auxiliary plug 50 , the lowermost and lower middle segments of the side surface 56 are separated by an annular shoulder 60 .
In the trim 10 , the auxiliary plug 50 is operatively coupled to a collar 62 of the check valve assembly which is attached to the bottom end of the stem 64 of the valve including the trim 10 . When viewed from the perspective shown in FIG. 1 , the collar 62 defines a top surface 66 , a bottom surface 68 , and a side surface 70 . The side surface 70 is also not of uniform outer diameter, but rather includes two (2) side surface sections or segments which are of differing outer diameter. In this regard, that segment of the side surface 70 extending to the top surface 66 exceeds the outer diameter of that segment of the side surface 70 extending to the bottom surface 68 . These upper and lower segments of the side surface 70 are separated by an annular shoulder 72 .
In the trim 10 , the auxiliary plug 50 is moveably attached to the collar 62 via the receipt of a portion of the auxiliary plug 50 into a complimentary interior cavity 74 defined by the collar 62 . As seen in FIG. 1 , that portion of the auxiliary plug 50 defining the uppermost segment of the side surface 56 thereof is captured and maintained within the interior cavity 74 , as is at least a portion of the auxiliary plug 50 which defines the upper middle segment of the side surface 56 thereof. The cooperative engagement between the auxiliary plug 50 and the collar 62 allows for the reciprocal movement of the auxiliary plug 50 relative to the collar 62 in a manner either decreasing or increasing the distance separating the shoulder 60 of the auxiliary plug 50 from the bottom surface 68 of the collar 62 . In this regard, the check valve assembly of the trim 10 preferably includes a biasing spring 76 which extends between the shoulder 60 and the bottom surface 68 . The biasing spring 76 normally biases the auxiliary plug 50 away from the collar 62 , i.e., maximizes the distance separating the shoulder 60 of the auxiliary plug 50 from the bottom surface 68 of the collar 62 . As will be recognized, the movement of the auxiliary plug 50 away from the collar 62 attributable to the action of the biasing spring 76 is eventually limited by the abutment of that portion of the auxiliary plug 50 defining the uppermost segment of the side surface 56 against an inner surface portion of the collar 62 which partially defines the interior cavity 74 thereof.
As indicated above, the pilot plug 28 of the trim 10 is moveable between a closed position wherein the sealing surface 36 thereof is sealed against the seat ring 24 , and an open position wherein the sealing surface 36 of the pilot plug 28 is separated from the seat ring 24 , thus allowing fluid to flow therebetween into the outflow passage 22 . The movement of the pilot plug 28 between its closed and open positions is facilitated by the upward and downward movement or actuation of the stem 64 , and more particularly, the collar 62 attached to one end thereof. As will be recognized, the reciprocal movement of the stem 64 and collar 62 as is needed to facilitate the movement of the pilot plug 28 between its closed and open positions is facilitated by an actuator which is operatively coupled to that end of the stem 64 opposite that having the collar 62 attached thereto. The downward movement of the stem 64 when viewed from the perspective shown in FIG. 1 causes the shoulder 72 defined by the collar 62 to act against the shoulder 40 of the pilot plug 28 in a manner which forces the sealing surface 36 of the pilot plug 28 against the seat ring 24 and maintains the sealed engagement therebetween.
When the pilot plug 28 is in its closed position, the biasing force exerted against the auxiliary plug 50 by the biasing spring 76 causes the sealing surface 58 of the auxiliary plug 50 to firmly engage and establish sealed contact with a portion of the pilot plug 28 at the inner periphery of the shoulder 44 thereof, as shown in FIG. 1 . As is further shown in FIG. 1 , in the check valve assembly integrated into the trim 10 , a biasing spring 78 extends between the shoulder 42 of the pilot plug 28 and the shoulder 72 of the collar 62 . From the perspective shown in FIG. 1 , when the stem 64 is actuated to facilitate the movement of the pilot plug 28 to the closed position, the downward biasing force exerted against the pilot plug 28 by the biasing spring 78 assists in maintaining the sealed engagement between the sealing surface 36 of the pilot plug 28 and the seat ring 24 even if the shoulder 72 of the collar 62 ceases to apply force directly to the shoulder 40 of the pilot plug 28 .
When the trim 10 is in a state or condition wherein the sealing surface 36 of the pilot plug 28 is sealed against the seat ring 24 and the sealing surface 58 of the auxiliary plug 50 is sealed against the pilot plug 28 , the pressure level P 1 in the inflow passage 20 will typically exceeds the pressure level P 2 in the outflow passage 22 . The pressure level P 1 also exists in the plug chamber 14 . In this regard, when viewed from the perspective shown in FIG. 1 , the plug chamber 14 is at the pressure level P 1 both above and below the level of a plug plate 80 which is attached to the top surface 30 of the pilot plug 28 through the use of, for example, fasteners such as bolts 82 . The plug plate 80 , which is used for reasons described in more detail below, includes at least one flow opening 84 which extends between the opposed top and bottom surfaces thereof.
In the valve including the trim 10 , that portion of the plug chamber 14 located above the plug plate 80 reaches the pressure level P 1 as a result of anticipated leakage which occurs between the inner surface of the plug sleeve 18 and the sealing rings 48 disposed in the side surface 34 of the pilot plug 28 . In this regard, the sealing rings 48 facilitate the pressurization of that portion of the plug chamber 14 located above the plug plate 80 in a regulated, metered manner. As is also seen in FIG. 1 , the side surface 34 of the pilot plug 28 is not of uniform outer diameter, but rather defines an annular shoulder 84 which is disposed in relative close proximity to the sealing surface 36 . Advantageously, the fluid pressure at the pressure level P 1 within that portion of the plug chamber 14 below the plug plate 80 and in between the side surface 34 and the inner surfaces of the disc stack 16 and plug sleeve 18 is able to act against the shoulder 84 in a manner supplementing or increasing the force of the sealed engagement between the sealing surface 36 and seat ring 24 . Such sealed engagement is further supplemented by the pressure level P 1 within that portion of the plug chamber 14 disposed below the plug plate 80 acting against the shoulders 40 , 42 , 44 of the pilot plug 28 . In this regard, fluid migrating between the pilot plug 28 and plug sleeve 18 into that portion of the plug chamber 14 disposed above the plug plate 80 is able to flow into the uppermost section of the bore 38 via the at least one flow opening 84 of the plug plate 80 . Even if the shoulder 72 of the collar 62 is firmly seated against the shoulder 40 of the pilot plug 28 , fluid is also able to flow into the upper middle and lower middle sections of the bore 38 via the channels 46 in the shoulder 40 , at least portions of which extend radially beyond that segment of the side surface 70 of the collar 62 of greater diameter extending to the top surface 66 thereof. Such flow results in the upper middle and lower middle sections of the bore 38 reaching the fluid pressure level P 1 along with the uppermost section of the bore 38 . Advantageously, the pressure level P 1 in the lower middle section of the bore 38 also acts against the shoulder 60 of the auxiliary plug 50 which supplements or enhances the sealed engagement between the sealing surface 58 of the auxiliary plug 50 and the pilot plug 28 .
In the valve including the trim 10 , the movement of the pilot plug 28 from its closed position to an open position is facilitated by the upward movement of the stem 64 , and hence the collar 62 , when viewed from the perspective shown in FIG. 1 , such upward movement being facilitated by the actuator cooperatively engaged to the stem 64 . The upward movement of the stem 64 initially causes the collar 62 to act against that portion of the auxiliary plug 50 residing within the interior cavity 74 as effectively removes the sealing surface 58 from its sealed engagement to the pilot plug 28 . The movement of the auxiliary plug 50 out of sealed engagement with the pilot plug 28 creates a balanced pressure condition between the plug chamber 14 and the outflow passage 22 . In this regard, the removal of the auxiliary plug 50 from its sealed engagement to the pilot plug 28 allows for open flow between the plug chamber 14 (including that portion disposed above the plug plate 80 ) and the outflow passage 22 via the bore 38 and flow passage 84 of the plug plate 80 .
The continued upward movement of the collar 62 after the auxiliary plug 50 is unseated from the pilot plug 28 results in the top surface 66 of the collar 62 acting against the bottom surface of the plug plate 80 . By virtue of the attachment of the plug plate 80 to the pilot plug 28 , the continued upward movement of the collar 62 after the same engages the plug plate 80 results in the sealing surface 36 of the pilot plug 28 being lifted off of and thus separated from the seat ring 24 , thereby causing the trim 10 to assume an open position.
In the trim 10 constructed in accordance with the present invention, it is contemplated that in a further mode of operation, a balanced pressure condition between the plug chamber 14 and outflow passage 22 may be achieved if the pilot plug 28 is in its closed position, but the pressure level P 2 in the outflow passage 22 exceeds the pressure level P 1 in the inflow passage 20 and plug chamber 14 . In this instance, it is contemplated that the pressure level P 2 will act against the bottom surface 54 of the auxiliary plug 50 in a manner facilitating the compression of the biasing spring 76 and removal of the sealing surface 58 from its sealed engagement to the pilot plug 28 . The upward movement of the auxiliary plug 50 by virtue of the compression of the biasing spring 76 is accommodated by the clearance between that portion of the auxiliary plug 50 residing within the interior cavity 74 and those surfaces of the collar 62 defining the interior cavity 74 . Once the auxiliary plug 50 is unseated from the pilot plug 28 , fluid is able to flow into the lower middle and upper middle sections of the bore 38 , and thereafter into the uppermost section of the bore 38 via the channels 46 disposed in the shoulder 40 . Fluid flowing into the uppermost section of the bore 38 is in turn able to flow into that portion of the plug chamber 14 disposed above the plug plate 80 via the flow opening 84 within the plug plate 80 . The equalization of the pressure level in the plug chamber 14 with the pressure level in the outflow passage 22 results in the sealing surface 58 of the auxiliary plug 50 being returned to sealed engagement to the pilot plug 28 by operation of the biasing spring 76 . Similarly, the sealed engagement between the sealing surface 36 of the pilot plug 28 and the seat ring 24 is maintained by the biasing spring 78 .
The check valve assembly integrated into the trim 10 comprises the auxiliary plug 50 , collar 62 and biasing springs 76 , 78 . Importantly, the functional attributes provided to the trim 10 by the check valve assembly allow the trim to achieve a Class V shut-off when subjected to an operational condition wherein the pressure level P 1 within the inflow passage 20 and plug chamber 14 exceeds the pressure level P 2 in the outflow passage 22 . The unique structural and functional attributes of the trim 10 also allow the same to achieve a Class IV shut-off when subjected to an operational condition wherein the pressure level P 2 in the outflow passage 22 rises to the level which exceeds that of the pressure level P 1 in the inflow passage 20 and plug chamber 14 .
Referring now to FIGS. 2 and 3 A- 3 C, there is shown a shut-off trim 100 constructed in accordance with a second embodiment of the present invention. The trim 100 comprises a main pilot plug 128 which, from the perspective shown in FIG. 2 , defines a top surface 130 , a bottom surface 132 , a side surface 134 , and a sealing surface 136 which extends between the bottom and side surfaces 132 , 134 . The pilot plug 128 is not solid, but rather has a bore 138 extending axially therethrough. The bore 138 is not of uniform diameter. Rather, the bore 138 defines four (4) different segments or sections, each of which is of a differing diameter. More particularly, the bore 138 includes an uppermost section, an upper middle section, and a lower middle section which are of a progressively decreasing diameter. The bore 138 also defines a lowermost section which is of the greatest diameter, exceeding that of the uppermost section thereof. The uppermost and upper middle sections of the bore 138 are separated by a shoulder 140 . Similarly, the upper middle and lower middle sections of the bore 138 are separated by an annular shoulder 142 . Additionally, disposed in the side surface 134 of that portion of the pilot plug 128 which defines the uppermost bore section is a plurality of sealing rings 148 which circumvent the pilot plug 128 and are used for reasons which will also be described in more detail below.
When the trim 100 is in a closed position within the exemplary valve including the same, the sealing surface 136 defined by the pilot plug 128 is firmly seated and sealed against the seat ring 24 . The trim 100 assumes an open position when, from the perspective shown in FIG. 2 , the pilot plug 128 is caused to move upwardly as results in the sealing surface 136 thereof effectively being separated from the seat ring 24 . Such separation allows fluid from within the plug chamber 14 to flow between the sealing surface 136 and seat ring 24 into outflow passage 22 .
In addition to the pilot plug 128 , the trim 100 includes a check valve assembly comprising a fastener 186 which is secured to that end of the stem 64 opposite the end portion cooperatively engaged to the actuator. As best seen in FIGS. 3A-3C , the fastener 186 comprises a cylindrically configured shank portion, an enlarged head portion which is formed on one end of the shank portion, and an externally threaded attachment portion which is threadably advanced into a complimentary, internally threaded aperture disposed within the end surface of the stem 64 . As is also apparent from FIGS. 3A-3C , the end portion of the stem 64 defining the end surface having the internally threaded aperture formed therein is enlarged relative to the remainder of the stem 64 . The end surface of the stem 64 which includes the internally threaded aperture therein also includes an annular groove or channel 188 which is formed therein and effectively circumvents the internally threaded aperture. The use of the channel 188 will be described in more detail below. The advancement of the attachment portion of the fastener 186 into the complimentary, internally threaded aperture of the stem 64 is continued until such time as the shank portion of the fastener 186 abuts the end surface of the stem 64 .
In addition to the fastener 186 , the check valve assembly comprises a generally cylindrical, tubular plug sleeve 190 which is cooperatively engaged to both the fastener 186 and stem 64 , and is reciprocally movable relative thereto in a manner which will be described in more detail below. An enlarged, cross-sectional view of the plug sleeve 190 standing alone is shown in FIG. 3D . The plug sleeve 190 includes a bore 192 which extends axially therethrough. The bore 192 is also not of uniform diameter. Rather, the bore defines two (2) different segments or sections, each of which is of differing diameter. More particularly, when viewed from the perspective shown in FIGS. 3A-3D , the bore 192 defines upper and lower sections which are separated from each other by an annular wall portion 194 of the plug sleeve 190 which is integrally connected to a main body portion 196 thereof, and protrudes from the inner surface of the main body portion 196 radially inwardly into the bore 192 . The wall portion 194 defines opposed, generally annular first and second shoulders 198 , 199 , the first shoulder 198 being directed toward the upper section of the bore 192 , and the second shoulder 199 being directed toward the lower section of the bore 192 which is of a reduced diameter in comparison to the upper section thereof.
In the check valve assembly of the trim 100 , the cooperative engagement of the plug sleeve 190 to the fastener 186 and stem 64 is facilitated by advancing the end portion of the main body portion 196 disposed furthest from the wall portion 194 into the channel 188 of the stem 64 . In this regard, the channel 188 has a configuration which is complimentary to that of the end portion of the main body portion 196 which is advanced thereinto. At the same time, the enlarged head portion of the fastener 186 is received into and reciprocally moveable within the reduced diameter lower section of the bore 192 . The shank portion of the fastener 186 resides within the increased diameter upper section of the bore 192 . The check valve assembly of the trim 100 further includes a biasing spring 178 which also resides within the upper section of the bore 192 of the plug sleeve 190 , and extends between the first shoulder 198 and the end surface of the stem 64 . The biasing spring 178 normally biases the plug sleeve 190 away from the stem 64 , i.e., maximizes the distance separating the wall portion 194 from the end surface of the stem 64 . In the check valve assembly, the movement of the plug sleeve 190 away from the stem 64 attributable to the action of the biasing spring 178 is eventually limited by the abutment of the second shoulder 199 defined by the wall portion 194 against the enlarged head portion of the fastener 186 . Conversely, the movement of the plug sleeve 190 toward the stem 64 is limited by the eventual abutment or bottoming out of the main body 196 of the plug sleeve 190 against the bottom, innermost surface of the channel 188 .
As indicated above, the pilot plug 128 of the trim 100 is movable between a closed position wherein the sealing surface 136 is sealed against the seat ring 24 , and an open position wherein the sealing surface 136 is separated from the seat ring 24 , thus allowing fluid to flow therebetween into the outflow passage 22 . The movement of the pilot plug 128 between its closed and open positions is facilitated by the upward and downward movement or actuation of the stem 64 . The reciprocal movement of the stem 64 as is needed to facilitate the movement of the pilot plug 128 between its closed and open positions is facilitated by an actuator which is operatively coupled to that end of the stem 64 opposite that having the fastener 184 attached thereto. The downward movement of the stem 64 when viewed from the perspective shown in FIG. 2 causes a peripheral portion of the end surface thereof having the internally threaded aperture and channel 188 formed therein to act against the shoulder 140 of the pilot plug 128 in a manner which forces the sealing surface 136 of the pilot plug 128 against the seat ring 24 and maintains the sealed engagement therebetween.
When the pilot plug 128 is in its closed position, the biasing force exerted against the plug sleeve 190 by the biasing spring 178 causes an annular sealing surface 197 defined by the main body portion 196 of the plug sleeve 190 to firmly engage and establish sealed contact with a portion of the pilot plug 128 at the inner periphery of the shoulder 142 thereof in the manner shown in FIG. 3A . Further, when the trim 100 is in a state or condition wherein the sealing surface 136 of the pilot plug 128 is sealed against the seat ring 24 and the sealing surface 197 of the plug sleeve 190 is sealed against the pilot plug 128 , the pressure level P 1 in the inflow passage 20 will typically exceed the pressure level P 2 in the outflow passage 22 . The pressure level P 1 also exists in the plug chamber 14 . In this regard, when viewed from the perspective shown in FIG. 2 , the plug chamber 14 is at the pressure level P 1 both above and below the level of a plug plate 180 which is attached to the top surface 130 of the pilot plug 128 through the use of, for example, fasteners such as bolts 182 . The plug plate 180 includes flow openings 184 which are disposed therein and extend between the opposed top and bottom surfaces thereof.
In the valve including the trim 100 , that portion of the plug chamber 14 located above the top surface 130 of the pilot plug 128 reaches the pressure level P 1 as the result of anticipated leakage which occurs between the inner surface of the plug sleeve 18 and the sealing rings 148 disposed in the side surface 134 of the pilot plug 128 . In this regard, the sealing rings 148 facilitate the pressurization of that portion of the plug chamber 14 located above the pilot plug 128 in a regulated, metered manner. As seen in FIG. 2 , the side surface 134 of the pilot plug 128 is not of uniform outer diameter, but rather defines an annular shoulder 184 which is disposed in relative close proximity to the sealing surface 136 . Advantageously, fluid pressure at the pressure level P 1 within that portion of the plug chamber 14 below the top surface 130 and in between the side surface 134 and the inner surfaces of the disc stack 16 and plug sleeve 18 is able to act against the shoulder 184 in a manner supplementing or increasing the force of the sealed engagement between the sealing surface 136 and seat ring 24 . Such sealed engagement is further supplemented by the pressure level P 1 within that portion of the plug chamber 14 disposed above the pilot plug 128 acting against the top surface 130 thereof. The pressure level P 1 also acts against the shoulders 140 , 142 within the bore 138 of the pilot plug 128 , thus further supplementing the force of the sealed engagement to be between the sealing surface 136 and the seat ring 24 . In this regard, fluid migrating between the pilot plug 128 and plug sleeve 18 into that portion of the plug chamber 14 disposed above the pilot plug 128 is able to flow into the uppermost and upper middle sections of the bore 138 to act against the shoulders 140 , 142 via the flow openings 184 of the plug plate 180 and one or more additional flow openings 185 which are disposed in the peripheral portion of the enlarged end portion of the stem 64 having the internally threaded aperture and the channel 188 formed therein. Even if the end surface of the stem 64 is firmly seated against the shoulder 140 of the pilot plug 128 , fluid is able to flow into the upper middle section of the bore 138 via the flow openings 185 . Such flow results in the uppermost and upper middle sections of the bore 138 reaching the fluid pressure level P 1 .
Moreover, in the valve including the trim 100 , the movement of the pilot plug 128 from its closed position to its open position is facilitated by the upward movement of the stem 64 , such upward movement being facilitated by the actuator cooperatively engaged to the stem 64 . The upward movement of the stem 64 initially causes the head portion of the fastener 186 to act against the shoulder 199 defined by the wall portion 194 of the plug sleeve 190 in a manner which effectively removes the sealing surface 197 of the plug sleeve 190 from its sealed engagement to the pilot plug 128 . The movement of the plug sleeve 190 out of sealed engagement with the pilot plug 128 creates a balanced pressure condition between the plug chamber 14 and outflow passage 22 . In this regard, the removal of the plug sleeve 190 from its sealed engagement to the pilot plug 128 allows for open flow between the plug chamber 14 and the outflow passage 22 via the bore 138 , the flow passages 184 of the plug plate 180 , and the flow passages 185 within the enlarged end portion of the stem 64 .
The continued upward movement of the stem 64 after the plug sleeve 190 is unseated from the pilot plug 128 results in the enlarged end portion of the stem 64 acting against the bottom surface of the plug plate 180 . By virtue of the attachment of the plug plate 180 to the pilot plug 128 , the continued upward movement of the stem 64 after the same engages the plug plate 180 results in the sealing surface 136 of the pilot plug 128 being lifted off of and thus separated from the seat ring 24 , thereby causing the trim 100 to assume an open position.
In the trim 100 , it is contemplated that in a further mode of operation, a balanced pressure condition between the plug chamber 14 and the outflow passage 22 may be achieved if the pilot plug 128 is in its closed position, but the pressure level P 2 in the outflow passage 22 exceeds the pressure level P 1 in the inflow passage 20 and plug chamber 14 . In this instance, it is contemplated that the pressure level P 2 will act against an annular end surface 195 of the plug sleeve 190 which is defined by the main body portion 196 thereof. In this regard, the sealing surface 197 extends to the outer peripheral edge of the end surface 195 . More particularly, the pressure level P 2 reaches the end surface 195 via the lowermost and lower middle sections of the bore 138 , and acts against the end surface 195 in a manner facilitating the compression of the biasing spring 178 and removal of the sealing surface 197 from its sealed engagement to the pilot plug 128 . The upward movement of the plug sleeve 190 by virtue of the compression of the biasing spring 178 is accommodated by the clearance between that end surface of the main body portion 196 opposite the end surface 195 and the bottom of the channel 188 . Once the plug sleeve 190 is unseated from the pilot plug 128 , fluid is able to flow from the outflow passage 22 into that portion of the plug chamber 14 above the pilot plug 128 via the bore 138 and the flow passages 185 , 184 . The equalization of the pressure level in the plug chamber 14 with the pressure level in the outflow passage 22 results in the sealing surface 197 of the plug sleeve 190 being returned to sealed engagement to the pilot plug 128 by operation of the biasing spring 178 . The check valve assembly integrated to the trim 100 provides the same functional characteristics of the trim 10 described above.
Referring now to FIGS. 4A-4C , there is shown in different states of actuation a check valve assembly 200 which may be integrated into a shut-off trim constructed in accordance with a third embodiment of the present invention, the check valve assembly 200 shown in FIGS. 4A-4C being used as an alternative to the check valve assembly shown in FIGS. 3A-3D . In this regard, the check valve assembly 200 is used in conjunction with the same pilot plug 128 possessing the same structural and functional attributes as described above in relation to the trim 100 . The check valve assembly 200 is also used in conjunction with the aforementioned plug plate 180 which is attached to the pilot plug 128 in the same manner described above in relation to the trim 100 .
The check valve assembly 200 integrated to the trim constructed in accordance with the third embodiment of the present invention comprises an auxiliary plug 286 which is secured to that end of the stem 64 opposite the end portion cooperatively engaged to the actuator. The auxiliary plug 286 comprises a cylindrically configured main body portion 287 having an elongate stem portion 289 protruding therefrom. Disposed within and extending through the stem portion 289 is an elongate slot 291 . Additionally, disposed in the main body portion 287 is an annular channel 293 of a prescribed depth, the channel 293 circumventing the base of the stem portion 289 . The auxiliary plug 286 further defines an annular plan flange portion 295 which circumvents the channel 293 , and thus also circumvents the base of the stem portion 289 .
In the check valve assembly 200 , the stem portion 289 of the auxiliary plug 286 is slideably advanced into a complimentary aperture disposed within the end surface of the enlarged end portion of the stem 64 . Subsequent to the advancement of the stem portion 289 into the complimentary aperture within the stem 64 , a pin 297 is advanced through the stem 64 and through the slot 291 disposed within the stem portion 289 . As seen in FIGS. 4A-4C , the advancement of the pin 297 through the slot 291 allows for the reciprocal movement of the auxiliary plug 286 toward and away from the stem 64 , but maintains the auxiliary plug 286 in attachment to the stem 64 .
As is apparent from FIGS. 4A-4C and as indicated above, the end portion of the stem 64 defining the end surface having the aperture formed therein is enlarged relative to the remainder of the stem 64 . The end surface of the stem 64 which includes such aperture for receiving the stem portion 289 also includes an annular groove or channel 288 which is formed therein and circumvents the aforementioned aperture. The use of the channel 288 will be described in more detail below.
In the check valve assembly 200 , the cooperative engagement of the auxiliary plug 286 to the stem 64 is facilitated the advancing the stem portion 289 into the complimentary aperture in the end surface defined by the enlarged end portion of the stem 64 , and securing the auxiliary plug 286 to the stem 64 through the use of the pin 297 advanced through the slot 291 within the stem portion 289 . At the same time, the flange portion 295 of the auxiliary plug 286 is slidably advanced into the channel 288 which has a configuration complimentary to that of the flange portion 295 . As is also apparent from FIGS. 4A-4C , the check valve assembly 200 further includes a biasing spring 278 which is disposed within the channel 293 , and extends between the main body portion 287 of the auxiliary plug 286 and a portion of the end surface of the enlarged end portion of the stem 64 which circumvents the aperture therein for accommodating the stem portion 289 . The biasing spring 278 normally biases the auxiliary plug 286 away from the stem 64 . In the check valve assembly 200 , the movement of the auxiliary plug 286 away from the stem 64 attributable to the action of the biasing spring 278 is eventually limited by the abutment of the pin 297 against that end of the slot 291 disposed closest to the distal end of the stem portion 289 . Conversely, the movement of the auxiliary plug 286 toward the stem 64 is limited by the abutment of the pin 297 against the opposite end slot 291 and/or the abutment or bottoming out of the flange portion 295 of the auxiliary plug 286 against the bottom of the channel 288 within the enlarged end portion of the stem 264 .
The pilot plug 128 of the trim including the check valve assembly 200 is movable between a closed position wherein the sealing surface 136 is sealed against the seat ring 24 , and an open position wherein the sealing surface 136 is separated from the seat ring 24 , thus allowing fluid to flow therebetween into the outflow passage 22 . The movement of the pilot plug 128 between its closed and open positions is facilitated by the upward and downward movement or actuation of the stem 64 . As in the prior embodiments discussed above, the reciprocal movement of the stem 64 as is needed to facilitate the movement of the pilot plug 128 between its closed and open positions is facilitated by an actuator which is operatively coupled to that end of the stem 64 opposite that having the auxiliary plug 286 attached thereto. The downward movement of the stem 64 when viewed from the perspective shown in FIGS. 4A-4C causes a peripheral portion of the end surface thereof having the aperture and channel 288 formed therein to act against the shoulder 140 of the pilot plug 128 in a manner which forces the sealing surface 136 of the pilot plug 128 against the seat ring 24 and maintains the sealed engagement therebetween.
When the pilot plug 128 is in its closed position, the biasing force exerted against the auxiliary plug 286 by the biasing spring 278 causes an annular sealing surface 299 defined by the main body portion 287 of the auxiliary plug 286 to firmly engage and establish sealed contact with a portion of the pilot plug 128 at the inner periphery of the shoulder 142 thereof in the manner shown in FIG. 4A . Further, when the trim including the check valve assembly 200 is in a state or condition wherein the sealing surface 136 of the pilot plug 128 is sealed against the seat ring 24 and the sealing surface 299 of the auxiliary plug 286 is sealed against the pilot plug 128 , the pressure level P 1 in the inflow passage 20 will typically exceed the pressure level P 2 in the outflow passage 22 . The pressure level P 1 also exists in the plug chamber 14 . In this regard, when viewed from the perspective shown in FIGS. 4A-4C , the plug chamber 14 is at the pressure level P 1 both above and below the level of a plug plate 180 which is attached to the top surface 130 of the pilot plug 128 through the use of the bolts 182 . As indicated above, the plug plate 180 includes flow openings 184 which are disposed therein and extend between the opposed top and bottom surfaces thereof.
In the valve including the trim having the check valve assembly 200 , that portion of the plug chamber 14 located above the top surface 130 of the pilot plug 128 reaches the pressure level P 1 as the result of anticipated leakage which occurs between the inner surface of the plug sleeve 18 and the sealing rings 148 disposed in the side surface 134 of the pilot plug 128 . In this regard, the sealing rings 148 facilitate the pressurization of that portion of the plug chamber 14 located above the pilot plug 128 in a regulated, metered manner. As indicated above, the side surface 134 of the pilot plug 128 is not of uniform outer diameter, but rather defines an annular shoulder 184 which is disposed in relative close proximity to the sealing surface 136 . Advantageously, fluid pressure at the pressure level P 1 within that portion of the plug chamber 14 below the top surface 130 and in between the side surface 134 and the inner surfaces of the disc stack 16 and plug sleeve 18 is able to act against the shoulder 184 in a manner supplementing or increasing the force of the sealed engagement between the sealing surface 136 and seat ring 24 . Such sealed engagement is further supplemented by the pressure level P 1 within that portion of the plug chamber 14 disposed above the pilot plug 128 acting against the top surface 130 thereof. The pressure level P 1 also acts against the shoulders 140 , 142 within the bore 138 of the pilot plug 128 , thus further supplementing the force of the sealed engagement to be between the sealing surface 136 and the seat ring 24 . In this regard, fluid migrating between the pilot plug 128 and plug sleeve 18 into that portion of the plug chamber 14 disposed above the pilot plug 128 is able to flow into the uppermost and upper middle sections of the bore 138 to act against the shoulders 140 , 142 via the flow openings 184 of the plug plate 180 and one or more additional flow openings 285 which are disposed in the peripheral portion of the enlarged end portion of the stem 64 having the aperture and the channel 288 formed therein. Even if a portion of the end surface of the stem 64 is firmly seated against the shoulder 140 of the pilot plug 128 , fluid is able to flow into the upper middle section of the bore 138 via the flow openings 285 . Such flow results in the uppermost and upper middle sections of the bore 138 reaching the fluid pressure level P 1 .
Moreover, in the valve including the trim having the check valve assembly 200 , the movement of the pilot plug 128 from its closed position to its open position is facilitated by the upward movement of the stem 64 , such upward movement being facilitated by the actuator cooperatively engaged to the stem 64 . The upward movement of the stem 64 initially causes the pin 297 to act against the stem portion 289 of the auxiliary plug 286 in a manner which effectively removes the sealing surface 299 of the auxiliary plug 286 from its sealed engagement to the pilot plug 128 . The movement of the auxiliary plug 286 out of sealed engagement with the pilot plug 128 creates a balanced pressure condition between the plug chamber 14 and outflow passage 22 . In this regard, the removal of the auxiliary plug 286 from its sealed engagement to the pilot plug 128 allows for open flow between the plug chamber 14 and the outflow passage 22 via the bore 138 , the flow passages 184 of the plug plate 180 , and the flow passages 285 within the enlarged end portion of the stem 64 .
The continued upward movement of the stem 64 after the auxiliary plug 286 is unseated from the pilot plug 128 results in the enlarged end portion of the stem 64 acting against the bottom surface of the plug plate 180 . By virtue of the attachment of the plug plate 180 to the pilot plug 128 , the continued upward movement of the stem 64 after the same engages the plug plate 180 results in the sealing surface 136 of the pilot plug 128 being lifted off of and thus separated from the seat ring 24 , thereby causing the trim including the check valve assembly 200 to assume an open position.
In the trim of the third embodiment including the check valve assembly 200 , it is contemplated that in a further mode of operation, a balanced pressure condition between the plug chamber 14 and the outflow passage 22 may be achieved if the pilot plug 128 is in its closed position, but the pressure level P 2 in the outflow passage 22 exceeds the pressure level P 1 in the inflow passage 20 and plug chamber 14 . In this instance, it is contemplated that the pressure level P 2 will act against a circular end surface 283 of the auxiliary plug 286 which is defined by the main body portion 287 thereof. In this regard, the sealing surface 299 extends to the outer peripheral edge of the end surface 283 . More particularly, the pressure level P 2 reaches the end surface 283 via the lowermost and lower middle sections of the bore 138 , and acts against the end surface 283 in a manner facilitating the compression of the biasing spring 278 and removal of the sealing surface 299 from its sealed engagement to the pilot plug 128 . The upward movement of the auxiliary plug 286 by virtue of the compression of the biasing spring 278 is accommodated by the clearance between the flange portion 295 and the bottom of the channel 288 . Once the auxiliary plug 286 is unseated from the pilot plug 128 , fluid is able to flow from the outflow passage 22 into that portion of the plug chamber 14 above the pilot plug 128 via the bore 138 and the flow passages 285 , 184 . The equalization of the pressure level in the plug chamber 14 with the pressure level in the outflow passage 22 results in the sealing surface 299 of the auxiliary plug 286 being returned to sealed engagement to the pilot plug 128 by operation of the biasing spring 278 . The check valve assembly 200 provides the same functional characteristics of the trim 10 described above.
Referring now to FIGS. 5 and 6 A- 6 B, there is shown a shut-off trim 300 constructed in accordance with a fourth embodiment of the present invention. The trim 300 comprises a pilot plug 328 which, from the perspective shown in FIG. 5 , defines a top surface 330 , a bottom surface 332 , a side surface 334 , and a sealing surface 336 which extends between the bottom and side surfaces 332 , 334 . The pilot plug 328 is not solid, but rather has a bore 338 extending axially therethrough. The bore 338 is not of uniform diameter. Rather, the bore 338 defines three (3) different segments or sections, each of which is of a differing diameter. More particularly, the bore 338 includes an upper section and a middle section which is of a reduced diameter in comparison to the upper section. The bore 338 also defines a lower section which is of the greatest diameter, exceeding that of the upper section thereof. The upper and middle sections of the bore 338 are separated by a shoulder 340 . Disposed in the side surface 334 of that portion of the pilot plug 328 which defines the upper bore section is a plurality of sealing rings 348 which circumvent the pilot plug 328 and are used for reasons which will also be described in more detail below.
When the trim 300 is in a closed position within the exemplary valve including the same, the sealing surface 336 defined by the pilot plug 328 is firmly seated and sealed against the seat ring 24 . The trim 300 assumes an open position when, from the perspective shown in FIG. 2 , the pilot plug 328 is caused to move upwardly as results in the sealing surface 336 thereof effectively being separated from the seat ring 24 . Such separation allows fluid from within the plug chamber 14 to flow between the sealing surface 336 and seat ring 24 into outflow passage 22 .
The pilot plug 328 included in the trim 300 further includes a check valve assembly 301 which is shown with particularity in FIGS. 6A and 6B . More particularly, the check valve assembly 301 comprises a flow passage 303 which extends from the top surface 330 of the pilot plug 328 to and into fluid communication with the lower section of the bore 338 thereof in the manner best shown in FIG. 5 . The flow passage 303 is not of uniform inner diameter. Rather, when viewed from the perspective shown in FIG. 5 , the flow passage 303 includes an upper section and a lower section which are separated from each other by an annular shoulder 305 , the diameter of the upper section exceeding that of the lower section. Disposed within the upper section of the flow passage 303 is a check ball 307 . The diameter of the check ball 307 presents the same from entering into the lower section of the flow passage 303 . The check ball 307 is maintained within the upper section of the flow passage 303 by an annular cap 309 which is partially advanced into the upper section of the flow passage 303 , and extends in substantially flush relation to the top surface 330 of the pilot plug 328 . At least a portion of that surface of the pilot plug 328 defining the upper section of the flow passage 303 is internally threaded, with the outer surface of the cap 309 being externally threaded so as to provide for the threadable engagement of the cap 309 to the plug 328 .
The check valve assembly 301 further comprises a biasing spring 311 which is disposed within the upper section of the flow passage 303 . One end of the biasing spring 311 is abutted against or engaged to the check ball 307 , with the opposite end of the biasing spring 311 being abutted against that end surface of the cap 309 which is opposite the end surface extended in substantially flush relation to the top surface 330 of the pilot plug 328 . As seen in FIG. 6A , the biasing spring 311 normally biases the check ball 307 against the inner peripheral edge of the shoulder 305 , thus causing the check ball 307 to define a blockage or seal between the upper and lower sections of the flow passage 303 . By virtue of its annular configuration, the cap 309 defines a flow opening which extends axially therethrough and facilitates the fluid communication between the flow passage 303 and that portion of the plug chamber 14 disposed above the pilot plug 328 when viewed from the perspective shown in FIG. 5 .
The pilot plug 328 of the trim 300 is movable between a closed position wherein the sealing surface 336 is sealed against the seat ring 24 , and an open position wherein the sealing surface 336 is separated from the seat ring 24 , thus allowing fluid to flow therebetween into the outflow passage 22 . The movement of the pilot plug 328 between its closed and open positions is facilitated by the upward and downward movement or actuation of the stem 64 . As in the prior embodiments discussed above, the reciprocal movement of the stem 64 as is needed to facilitate the movement of the pilot plug 328 between its closed and open positions is facilitated by an actuator which is operatively coupled thereto. The downward movement of the stem 64 when viewed from the perspective shown in FIG. 5 causes a peripheral portion of the end surface thereof to act against the shoulder 340 of the pilot plug 328 in a manner which forces the sealing surface 336 of the pilot plug 328 against the seat ring 24 and maintains the sealed engagement therebetween.
When the pilot plug 328 is in its closed position, the biasing force exerted against the check ball 307 by the biasing spring 311 causes the check ball 307 to be firmly seated and sealed against the shoulder 305 , thus effectively blocking fluid communication between the outflow passage 22 and plug chamber 14 as would otherwise be provided by the flow passage 303 . Further, when the trim 300 is in a state or condition wherein the sealing surface 336 of the pilot plug 328 is sealed against the seat ring 24 and the check ball 307 is sealed against the shoulder 305 , the pressure level P 1 in the inflow passage 20 will typically exceed the pressure level P 2 in the outflow passage 22 . The pressure level P 1 also exists in the plug chamber 14 . In this regard, when viewed from the perspective shown in FIG. 5 , the plug chamber 14 is at the pressure level P 1 both above and below the level of a plug plate 380 which is attached to the top surface 330 of the pilot plug 328 through the use the bolts 382 . The plug plate 380 includes flow openings 384 which are disposed therein and extend between the opposed top and bottom surfaces thereof.
In the valve including the trim 300 , that portion of the plug chamber 14 located above the top surface 330 of the pilot plug 328 reaches the pressure level P 1 as the result of anticipated leakage which occurs between the inner surface of the plug sleeve 18 and the sealing rings 348 disposed in the side surface 334 of the pilot plug 328 . In this regard, the sealing rings 348 facilitate the pressurization of that portion of the plug chamber 14 located above the pilot plug 328 in a regulated, metered manner. The side surface 334 of the pilot plug 328 is not of uniform outer diameter, but rather defines an annular shoulder 384 which is disposed in relative close proximity to the sealing surface 336 . Advantageously, fluid pressure at the pressure level P 1 within that portion of the plug chamber 14 below the top surface 330 and in between the side surface 334 and the inner surfaces of the disc stack 16 and plug sleeve 18 is able to act against the shoulder 384 in a manner supplementing or increasing the force of the sealed engagement between the sealing surface 336 and seat ring 24 . Such sealed engagement is further supplemented by the pressure level P 1 within that portion of the plug chamber 14 disposed above the pilot plug 328 acting against the top surface 330 thereof. The pressure level P 1 also acts against the shoulder 340 within the bore 338 of the pilot plug 328 , thus further supplementing the force of the sealed engagement to be between the sealing surface 336 and the seat ring 24 . In this regard, fluid migrating between the pilot plug 128 and plug sleeve 18 into that portion of the plug chamber 14 disposed above the pilot plug 328 is able to flow into the upper section of the bore 338 to act against the shoulders 140 via the flow openings 384 of the plug plate 380 . Such flow results in the upper section of the bore 338 reaching the fluid pressure level P 1 . Fluid at the pressure level P 1 also flows from the plug chamber 14 into the upper section of the flow passage 303 via the flow opening defined by the cap 309 . Such fluid at the pressure level P 1 acts against the check ball 307 in a manner supplementing the biasing force exerted thereagainst by the biasing spring 311 , thus enhancing the sealed engagement of the check ball 307 against the shoulder 305 .
Moreover, in the valve including the trim 300 having the check valve assembly 301 , the movement of the pilot plug 328 from its closed position to its open position is facilitated by the upward movement of the stem 64 , such upward movement being facilitated by the actuator cooperatively engaged to the stem 64 . When the pilot plug 328 is in its closed position, a sealing surface defined by the enlarged end portion of the stem 64 engages and is sealed against the inner peripheral rim defined by the shoulder 340 of the pilot plug 328 , thus effectively creating a blockage or barrier between the upper and middle sections of the bore 338 . The upward movement of the stem 64 initially causes the sealing surface of the stem 64 to be removed from its sealed engagement to the pilot plug 328 , thus creating a balanced pressure condition between the plug chamber 14 and outflow passage 22 . In this regard, the removal of the sealing surface defined by the enlarged end portion of the stem 64 from its sealed engagement to the pilot plug 328 allows for open flow between the plug chamber 14 and the outflow passage 22 via the bore 338 and flow passages 384 of the plug plate 380 .
The continued upward movement of the stem 64 after the sealing surface thereof is unseated from the pilot plug 328 results in the enlarged end portion of the stem 64 acting against the bottom surface of the plug plate 380 . By virtue of the attachment of the plug plate 380 to the pilot plug 328 , the continued upward movement of the stem 64 after the same engages the plug plate 380 results in the sealing surface 336 of the pilot plug 328 being lifted off of and thus separated from the seat ring 24 , thereby causing the trim 300 to assume an open position.
In the trim 300 including the check valve assembly 301 , it is contemplated that in a further mode of operation, a balanced pressure condition between the plug chamber 14 and the outflow passage 22 may be achieved if the pilot plug 328 is in its closed position, but the pressure level P 2 in the outflow passage 22 exceeds the pressure level P 1 in the inflow passage 20 and plug chamber 14 . In this instance, it is contemplated that the pressure level P 2 will act against the check ball 307 in a manner overcoming the biasing force exerted thereagainst by the biasing spring 311 , thus effectively forcing the check ball 307 toward the cap 309 and out of its sealed engagement to the shoulder 305 . As will be recognized, since the diameter of the check ball 307 is less than that of the upper section of the flow passage 303 , the movement of the check ball 307 out of sealed engagement to the shoulder 305 effectively unblocks the flow passage 303 , thus allowing open fluid communication between the outflow passage 22 and that portion of the plug chamber 14 disposed above the pilot plug 328 . As will be recognized, the pressure level P 2 reaches the check ball 307 via the lower section of the bore 338 and the lower section of the flow passage 303 . As indicated above, once the check ball 307 is unseated from the shoulder 305 , fluid is able to flow from out outflow passage 22 into that portion of the plug chamber 14 above the pilot plug 328 via the lower section of the bore 338 and flow passage 303 . The equalization of the pressure level in the plug chamber 14 with the pressure level in the outflow passage 22 results in the check ball 307 of the check valve assembly 301 being returned to sealed engagement to the shoulder 305 by operation of the biasing spring 311 . The trim 300 including the check valve assembly 301 provides the same functional characteristics of the trim 10 described above.
This disclosure provides exemplary embodiments of the present invention only. The scope of the present invention is not limited by these exemplary embodiments. Numerous variations, whether explicitly provided for by the specification or implied by the specification, such as variations in structure, dimension, type of material and manufacturing process may be implemented by one of skill in the art in view of this disclosure.
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In accordance with the present invention, there is provided a bi-directional shut-off trim for a valve which possesses the functional attributes of a pilot operated trim and a balanced trim through the integration of a spring loaded check valve into a pilot trim. In forward flow isolation, the bi-directional shut-off trim of the present invention acts as a normal pilot operated trim. In reverse flow, the check valve of the shut-off trim opens to balance the pressure on either side of the plug thereof.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an infant feeding device that closely approximates natural breast feeding in the sensory experiences provided to the baby and promotes parent-baby bonding 1 ) mechanically, as the feeding container simulates a breast in its fluid delivery, shape, texture, feel, and ease of infant attachment for suckling, and 2 ) psychologically, as the nurser is designed to permit both the infant and the parent to assume a natural position where the infant can feel the body heat and heartbeat of the parent, the parent's hands are free to cuddle the infant during feeding, and the infant's face is pressed against the nipple to stimulate the perioral area and imitate a breast.
[0003] One of the largest shortcomings of conventional baby bottles and modern nursers with improved shapes is that the devices do not provide the full maternal benefits that are a necessary part of maximizing sustenance to the child, both physically and psychologically. Even recently engineered feeding containers that deliver more fluid with less air are typically advanced as baby bottle substitutes to be used by an adult holding the bottle in one hand which is offered to an infant cradled by the the adult's opposite arm and hand. Both the adult's hands are devoted to feeding and not cuddling the infant, the infant is not positioned next to the chest area of the adult, and the infant's face is not pushed against the nipple. Thus, important bonding opportunities that are inherent in the practice of breast feeding are not available with ordinary bottle feeding. This deprives infants cared for by their fathers or other men such as grandfathers, who now take an active role in child rearing in industrialized societies, or by non-nursing mothers, surrogate parents, and other infant caretakers, of the important positive bonding advantages obtained by infants who breast feed, and deprives the adults of significant bonding experiences with the infant. This invention addresses these concerns.
[0004] 2. Description of Related Art
[0005] Myriad vessels with nipples, pap boats, and other nursing devices have been used for millenia for feeding infants as a substitute for breast feeding. In modern times, an elongated cylindrical bottle of glass or plastic, equipped with a cap and an enlongated latex nipple, became universally known and used as a conventional baby bottle. Only more recently have alternative feeding apparatuses been suggested as improvements over this basic design. These roughly fall into two groups: designs with a nipple that more closely approximate the shape of a human breast and designs that position the baby for feeding in a configuration more closely approximating that of an infant suckling from a breast.
[0006] In the former category, for example, Prentiss suggested an infant feeding container that was wider than a conventional baby bottle and had a nipple more closely approximating a breast-shape (U.S. Pat. No. 5,690,679; this and subsequent cited patents are expressly incorporated in their entireties by reference). This was said to more closely approximate the experience of natural breast feeding, and provide a bottle that was more stable for an older child to put down without tipping it over.
[0007] In U.S. Pat. No. 6,161,710, Dieringer and Suarez disclosed an improved natural nipple baby feeding apparatus which includes detachable inner and outer membranes which both extend substantially across a distance larger than the diameter of a standard baby bottle, providing a nipple surface more closely approximating a the areola of a human breast. The device was said to make it easier for a baby to “latch on” to in a manner similar to natural suckling of a breast, rather than sucking from an elongate smooth single rubber nipple of a conventional baby bottle, and hence, easier for the baby to alternate between breast feeding and bottle feeding. Prentiss suggested an infant feeding container in the overall shape of a breast, rather than just the nipple portion (U.S. Pat. No. 5,993,479). Holmquist provided a cushion under the nipple portion of a baby feeding apparatus and a spring-biased pressure plate to force a milk bag in the container portion toward the nipple as the milk level fell with the infant's feeding (U.S. Pat. No. 5,947,427). Griffin even more closely approximated a human nipple by suggesting nipple manufacture using a device formed from a mold taken of the nursing mother's breast so that the shape exactly replicated the mother's nipple (U.S. Pat. No. 5,108,686).
[0008] In the latter category of designs directed to positioning the infant, Jones disclosed a surrogate nursing bib that secured around the neck and around the waist of the wearer, and held a milk pouch that protruded from either of two orifices in the bib located on the chest of the wearer at the wearer's breast position (U.S. Pat. No. 5,086,517). Goldson and Goldson suggested a similar bib (U.S. Pat. No. 4,776,546). Beard and Beard suggested a nursing baby bottle holder that was a sling that could be draped around the neck of the person feeding the baby, which supported the baby bottle in a nursing position (U.S. Pat. No. 5,582,335).
[0009] It would be desirable to combine many of these desirable features with fluid delivery more closely approximating breast feeding to provide a baby nurser that more closely mimicks natural breast feeding and contributes to parent-infant bonding during feeding, and thus to the emotional stability of a healthy child.
BRIEF SUMMARY OF THE INVENTION
[0010] These objectives and others are provided by the present invention which describes an infant nurser that has a container that closely simulates the sensation provided by a mother's breast in its shape and fluid delivery and which is, in the preferred embodiment, attached to a shoulder sling and positioned over the breast of the person feeding the infant, leaving both arms free to caress the infant held in close proximity to the adult's chest. In an alternate embodiment, the same advanced design container may be attached to a hand strap so the infant can be fed as if the nurser were an ordinary baby bottle.
[0011] The two embodiments are illustrated in FIGS. 1 and 12, more fully described below. Briefly, the container has two main parts: a flexible, dome-shaped housing approximately in the form of a human female breast and having a centrally positioned aperture in the apex region of the housing and a securing means in the base rim region opposite the apex for holding a pouch in the interior of the housing and releasibly attaching the container to a hand strap or shoulder sling, and a pouch that contains fluids and conforms to the housing interior when placed inside it and comprises a collapsible bag having a nipple which protrudes through the housing aperture and allows passage of fluids therethrough when an infant suckles on the nipple, and an attachment collar and lid which holds a flanged end of the bag opposite the nipple through which fluids may be poured to fill the bag and hold fluids in it. Typical securing straps that hold the pouch in the dome housing have hook and loop fasteners such as Velcro™ so that the container can be easily emptied or filled by pulling apart the Velcro™ and putting in or taking out the pouch (illustrated in FIGS. 2 and 4). The bag of the pouch is preferably disposable plastic that doesn't need to be sterilized for repeated use, and the cap of the pouch has an attachment collar that holds and secures a flange on the bag and is threaded to receive a screw-on pouch lid (illustrated in FIGS. 5 to 7 ); the flange serves as a gasket, making the pouch leakproof when containing liquids and excluding air from the bag as the infant suckles.
[0012] The container is releasibly attached to either a hand strap or a shoulder sling. Preferred embodiments employing hook and loop fasteners, e.g., Velcro™, are illustrated in FIGS. 3 and 11. Both have container attachment sites that present a hook fastener area so that the container can be easily attached or removed from the sling or hand strap by simply placing the container on a Velcro™ patch on the sling or wrist strap and pulling it off. As mentioned above, in the preferred sling embodiment, the container attachment site is positioned over the breast of the person feeding the baby (FIG. 1). The hand strap embodiment positions the container attachment site in the palm area for convenience in feeding the infant by conventional means. In both cases, however, the suckling infant using a nurser of the invention has the benefit of of a feeding experience that simulates natural breast feeding in that the baby's face is pressed up against the container (as illustrated in FIG. 13) and the internal pouch slowly deflates while the baby is held up against the chest of the nurturing adult.
BRIEF DESCRIPTION OF THE FIGURES
[0013] To illustrate and explain the invention, the detailed description that follows make reference to the following annexed drawings:
[0014] [0014]FIG. 1 is a front prospective view of a nurser of the invention in place on a person who will feed an infant, which comprises a breast-shaped container attached to a shoulder sling.
[0015] [0015]FIG. 2 shows a back prospective view of the container portion of the nurser depicted in FIG. 1 detached from the sling, exposing the interior of the container and illustrating that the container comprises a dome-shaped housing which holds a lidded pouch that conforms to the interior shape of the apex region of the housing, with folded securing straps on the base rim of the housing holding the pouch inside the housing, and that the straps have loop surfaces of a Velcro™ or similar attachment means.
[0016] [0016]FIG. 3 shows a front prospective view of the sling portion of the nurser of FIG. 1 with the container portion detached, exposing a hook surface of a Velcro™ or other attachment means on the sling which conforms to the circular shape of the container so that the container illustrated in FIG. 2 may be attached by mechanical coupling to assemble the nurser for use as depicted in FIG. 1.
[0017] [0017]FIG. 4 is a back perspective view of the container of FIG. 2 illustrating the securing straps unfolded for removal of the pouch from the container housing and illustrating that the securing straps have hook surfaces of a Velcro™ or similar attachment means on the reverse side of the loop surface so that, when folded, the securing straps secure the pouch in the housing.
[0018] [0018]FIG. 5 is a side perspective view of a collapsible bag that holds fluid in the pouch and has a nipple on one end and a circular flanged opening on the other.
[0019] [0019]FIG. 6 is a side perspective view of an attachment collar and lid for the bag of the pouch.
[0020] [0020]FIG. 7 is a side perspective view of how the bag is inserted through the collar, nipple end first, until the bag flange meets the collar.
[0021] [0021]FIG. 8 is a front perspective view of the dome-shaped housing portion of the container which has an aperture in the apex region and securing straps attached in the base rim region.
[0022] [0022]FIG. 9 is a cross-sectional view of the container showing the strap attachment to the container and illustrating the pouch comprising the filled fluid bag with its collar in place in the container, and with the bag nipple protruding through the housing aperture, and further comprising a nipple cap.
[0023] [0023]FIG. 10 is an exploded side cross-sectional view of the container nipple area of FIG. 9 with the a nipple cap installed over the nipple.
[0024] [0024]FIG. 11 is a front perspective view of an alternative embodiment comprising a container attached to a hand strap instead of the sling of FIG. 2 and showing the same type of hook surface of a Velcro™ or other attachment means for attaching the container.
[0025] [0025]FIG. 12 is a front perspective view of the hand strap embodiment of the invention with the container attached, illustrating its placement in the palm of the hand of a person who will feed an infant.
[0026] [0026]FIG. 13 is a side perspective view of an infant suckling from a nurser of the invention, illustrating how the entire area of the infant's face around the mouth, including the nose, presses up against the nipple area of the nurser in use as an infant's does in breast feeding.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Various features of preferred embodiments of the invention are depicted in the figures. FIG. 1 is a front perspective view of a preferred embodiment of a nurser according to the invention, which is designated generally by the reference numeral 10 , which depicts a shoulder sling nurser briefly described above. Nurser 10 includes a flexible shoulder sling 12 to which is attached, positioned in the breast area of user's chest 14 depicted in the Figure as a woman, container 16 , which has the overall shape of a human breast in that housing 18 is dome-shaped with a nipple cap 20 protruding from the center of the apex region of the dome. Sling 12 fits over shoulder 22 of user 14 and under arm 24 as indicated, and is depicted as being slightly wider in shoulder region 22 and narrower under arm 24 for the comfort of user 14 , but the relative widths are immaterial so long as the sling holds container 16 in the breast area of the user's. Typical slings used for nursers of the invention are fabricated from heavy duty fabric or belting materials; preferred slings are sufficiently soft to be comfortable for the user to wear year round and are machine-washable, e.g., cotton, cotton blends, and the like, typically reinforced with some polymeric fibers to provide durability.
[0028] [0028]FIG. 2 illustrates container 16 removed from sling 12 and shows a back prospective view exposing the interior of housing 18 , which holds pouch 26 , and FIG. 3 shows a front perspective view of sling 12 with container 16 detached. Pouch 26 comprises bag 28 , which extends from its bottom near nipple cap 20 to its top at attachment collar 30 and lid 32 , to be more fully described below in descriptions of FIGS. 5 to 7 . At circular base rim 34 of housing 18 , four straps 36 are attached through four slots 38 that protrude from base rim 34 as tabs 46 . Straps 36 are arranged on base rim 34 in pairs of two opposite one another along the circumference of the circle. Though the Figure shows two slots 38 closer together on either side of housing 18 , they can be spaced further apart, as will become clearer in the description of FIG. 4 below. Surface 40 of straps 36 comprise loops in a loop pile of Velcro™ fabric to attach to hooks 42 in a hook pile of Velcro™ fabric attached to strap 12 as circular attachment surface 44 . Circular attachment surface 44 has the same circumference as base rim 34 so that container 16 can be neatly attached to sling 12 when nurser 10 is in use, and can be secured to sling 12 using standard means such as glueing or sewing.
[0029] Since FIG. 3 shows sling 12 when not worn by user 14 fastener 48 on the back side of the sling is exposed. Fixed length slings may be employed in the practice of the invention, but adjustable slings are preferred so that sling size can be changed for the comfort of user 14 and adjusted to fit different-sized users using buckle assembly 48 , but other buckle assemblies, ties, snaps, hooks and eyes, fabric latches, etc., alternative fasteners typically employed for belts and the like may also be employed (not shown). Buckle assembly 48 is comprised of slotted member 50 to which one end of sling 12 passes and is fixed to buckle member 50 in a stationary configuration by passing sling end 52 through a slot in 50 and joining end 52 to sling 12 at seam 54 by standard means such as sewing, riveting, or gluing. Buckle member 50 is sized to reversibly latch to buckle member 60 as a male-female joint. The other end 56 of sling 12 passes through cuff 58 as well as a slot on buckle member 60 , so that end 56 can be pulled at the discretion of the user to shorten or lengthen the sling. Many variations of coupling connections of this type, including standard belts and belt buckles fabricated to releasibly attach easily, are known to the skilled worker, particularly for the manufacture of child care and sports equipment.
[0030] [0030]FIG. 4 is a back perspective view of container 16 with securing straps 36 unfolded to illustrate how container 16 is opened to remove pouch 26 from housing 18 , exposing surface 62 on the other side of surface 40 of the strap. Surface 62 has hooks like those on surface 42 . Use of Velcro™ fabric for securing straps 36 provides a very convenient hook and loop attachment means for the straps, since surface 40 on the straps can interact with both surface 62 or surface 42 , providing attachment of the securing straps to each other to hold pouch 26 in housing 18 and to attach container 16 to strap 12 at surface 42 by mechanical coupling, providing nurser 10 of the invention. FIG. 4, like FIG. 2, shows straps 36 attached to housing 18 by passage through slots 38 in tabs 46 protruding from base rim 34 , but any attachment means known to the skilled artisan such as hinges or rings that mount straps 36 to housing 18 accomplish the same purpose may be employed in alternate embodiments (not shown).
[0031] [0031]FIG. 5 is a side perspective view of bag 28 , which is collapsible and holds whatever fluid is going to be fed to the infant, such as milk, formula, juice, or water, in pouch 26 . Preferred bags used in nursers of the invention are clear or translucent plastic and are disposable, but sterizable ones can also be used. Myriad polyethylene and the like materials are known to the skilled worker for the fabrication of bag 28 . Bag 28 is sized to fit inside housing 18 when assembled into pouch 26 to be more fully discussed below in the explanation of FIG. 9. Nipple 64 is located at the bottom of bag 28 , and has orifice 66 through which fluids flow when the infant suckles on the nurser. Circular flange 68 on the top of bag 28 is sized to be sufficiently large enough for pouring liquids into bag 28 and to fit snugly against surface 70 of collar when bag 28 is fitted through collar 30 as depicted in FIG. 7. The assembly of bag 28 , 30 and 32 together form pouch 26 , which holds fluids for the infant's consumption in container 16 without leakage. Therefore, lid 32 of FIG. 6 is sized to tightly fit collar 30 . FIG. 6 shows collar 30 having threads 72 that interact with corresponding threads in cap 32 (not shown), providing a screw-on pouch top, but a simple cork assembly (not shown) will suffice. However, the illustrated embodiment is much preferred because the assembly of flange 68 of bag 28 against surface 70 of collar 30 with lid 32 screwed on enhances the seal because the flange acts like a gasket between lid 32 and collar 30 . Thus, not only is fluid leakage minimized, but air entry into the bag as the infant feeds is also minimized, with consequent minimization of discomfort to the baby often observed with conventional baby bottles (to be more fully discussed below).
[0032] [0032]FIG. 8 is a front perspective view of dome-shaped housing 18 , which, without bag 28 , has aperature 72 in the apex region of the dome through which nipple 64 protrudes. Housing 18 is fabricated from a durable, pliable, resilient material, preferably plastic, sufficiently strong to provide a durable container 16 , but sufficiently soft and malleable to mimic a breast when a filled bag 28 is installed therein. As with bag 28 , any plastic materials are available to the skilled artisan for the fabrication of housing 18 , and preferred embodiments employ optimal plastics that function well together to achieve an optimal container 16 . Preferred plastics for use in all container components of the invention are sterilizable, preferably autoclavable, for home or hospital use. Housing 18 may even be flesh-colored and slightly textured like skin. It is an advantage of the invention that the nurser so closely resembles a breast that nipple confusion often observed when infants switch from a breast to a bottle, which interrupts feeding and can cause infants considerable distress, is minimized or eliminated.
[0033] [0033]FIG. 9 is a side cross-sectional view of container 16 of the invention. Strap 36 is joined to housing 18 by passage through slots 38 in tab portion 48 as previously described. The Figure illustrates cap 32 threaded at 72 onto collar 30 as previously described, with flange 68 flaring out from neck region 74 of bag 28 and to fit against surface 70 of cap 30 and held down by cap 32 so that fluids do not leak. Nipple 64 passes through aperture 72 , and has a circumferential indentation 74 that is sized to clip on to circumferential protrusion 84 of FIG. 10 in nipple cap 20 when the nurser is not in use (to be discussed below). The nipple design advantageously provides an excellent attachment site for the infant's mouth to easily grip and suckle. FIG. 9 also shows another important structural feature of the invention, namely that bag 28 fits against and ajoins interior surface 76 of the apex region of dome-shaped housing 18 when bag 28 contains fluid 78 . The design of collapsible bag 28 against pliable housing 18 held in place by straps 36 provides a unique container for nursers of the invention because both the bag and the housing act in concert to mimic the malleability and texture of a breast and collapse slightly against the face of the infant in the mouth and nose area as depicted in FIG. 13 (to be more fully discussed below). As shown in FIG. 9, in preferred embodiments, housing 18 is thinner in apex area 80 and thicker in area 82 near and at base rim 34 . Thicker base region 82 in housing 18 provides structural integrity to container 16 , and thinner apex region 76 provides the supple pliancy of the container area around the nipple. Moreover, the design allows for bag 28 to slowly deflate as fluid 78 drops in container 16 . Since lid 32 is screwed down on collar 32 when pouch 26 is prepared, with flange 68 on bag 28 acting like a gasket, fluid 78 is sucked out of container 16 with very little air delivery to the infant as it suckles, feeding is more comfortable for the baby and gas delivery to the intestinal tract is minimized, avoiding stomach cramps and frequent and/or excessive belching after feeding.
[0034] [0034]FIG. 10 is an exploded side cross-sectional view of the nipple area of FIG. 9 with the nipple cap 20 installed to cover nipple 64 . When nipple cap 20 covers nipple 64 , circumferential flange 84 in stem area 86 of nipple cover 20 clicks into place in circumferential indentation 74 in the stem area of nipple 64 (shown in FIG. 9). Circumferential indentation 74 in nipple 64 is sized to fit circumferential flange 84 of nipple cap 20 to protect nipple 64 when container 16 is not in use. FIGS. 9 and 10 together also show that flange 76 of nipple cap 20 fits snugly fit against housing 18 in the area around aperture 72 to protect the nipple and provide a detachable cap that is easy for the user to remove or replace and large enough to be readily found if misplaced by the user.
[0035] [0035]FIGS. 11 and 12 illustrate an alternate nurser embodiment to the sling depicted in FIG. 1, but using the same container. FIG. 11 is a front perspective view of hand strap 90 presenting circular attachment surface 92 which is analogous to, and the same size as, circular attachment surface 42 on sling 12 . Surface 92 has hooks that engage with the loops on surface 40 of securing straps 36 on container 16 to attach container 16 to the handstrap to provide nurser 100 depicted in FIG. 12. Hand strap 90 has an adjustable buckle assembly 94 corresponding to buckle assembly 48 of sling 12 shown in FIG. 3.
[0036] As shown in FIG. 12, which is a front perspective view of the handstrap embodiment, illustrating placement of a nurser of the invention in the palm region of user hand 102 . As shown by the arrow, strap end 96 is simply pulled through buckle 94 to fasten nurser 100 to the hand, so that infant 110 of FIG. 13 can be fed as with a conventional baby bottle. An advantage of the invention is that, since both the shoulder sling and the hand strap are designed to attach to the same container, either nurser 19 or nurser 100 can be conveniently provided in a kit with sling 12 , hand strap 90 , housing 18 , collar 30 and lid 32 , and nursers can be assembled for either breast-type or lap-type feeding at the option of the person feeding the infant by adding disposable bags 28 .
[0037] [0037]FIG. 13 is a perspective view of infant 110 suckling from container 16 . The drawing illustrates another important feature of the invention mentioned above, namely that the face of infant 110 in nose area 112 , chin area 114 and adjacent areas around lips 116 are pressed up against container 16 as the baby feeds from the nurser. This is what happens in natural breast feeding. When combined with the design of container 16 as described above, nursers of the invention more closely mimic natural breast feeding than previously described nursers by stimulating the sensory perceptive nerves of the infant in the perioral region of the face. The sling embodiment of FIG. 1 allows the free hands of the adult feeding adult to caress the baby and hold it close to the warmth, smell, and heartbeat of the adult. Taken together, the nurser of the invention provides an optimal bonding experience during feeding for fathers, non-nursing mothers, and other infant caretakers.
[0038] The above description is for the purpose of teaching the person of ordinary skill in the art how to practice the present invention, and it is not intended to detail all those obvious modifications and variations of it which will become apparent to the skilled worker upon reading the description. It is intended, however, that all such obvious modifications and variations be included within the scope of the present invention, which is defined by the following claims.
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A bonding nurser that can be used to closely approximate breast feeding mechanically and psychologically comprises a feeding container that simulates a breast in fluid delivery, shape, texture, feel, and ease of infant suckling releasibly attached to a sling so that the container is positioned on the breast area of the adult feeding the baby, and the adult's hands are free for cuddling the baby during feeding. The feeding container is a breast-shaped flexible housing that holds a collapsible bag which delivers milk or other fluids through a nipple protruding through the apex of the housing and is filled through a screw cap opening at the base opposite the apex and secured in the housing by retaining straps surfaced with Velcro™. When the container is assembled, i.e., a bag is positioned in the housing, the straps present a loop interface that mechanically couples the base of the container to a correspondingly sized hook-surfaced area on a shoulder strap (or a hand strap).
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electronic musical instrument utilizing neural nets more particularly, to an electronic musical instrument to generate musical patterns, such as a rhythm pattern and a bass pattern, using a neural net.
2. Description of the Prior Art
In a conventional electronic musical instrument having the function of an automatic rhythm pattern generation or an automatic accompaniment pattern generation, the patterns to be generated are previously stored in a memory. When any pattern is selected by a performer, the pattern is read from the memory and supplied to a musical tone generating circuit.
As described above, the conventional electronic musical instruments have only had a memory to generate musical patterns, such as a rhythm pattern and a bass pattern, so that available patterns are limited. Therefore, the musical representations have been scanty.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an electronic musical instrument which allows itself to generate more musical patterns by use of a neural net.
In accordance with the present invention, an electronic musical instrument utilizing neural nets comprises parameter input means for inputting a parameter, a neural net device for utilizing the parameter inputted from the parameter input means with internal organization, and change means for changing output data from the neural net device into musical pattern signal.
In the above-mentioned instrument, the neural net device is in advance learning, therefore, any input parameter results in a proper output by interpolation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a rhythm pattern generating instrument embodying the present invention.
FIG. 2 shows correlation between the first series' neurons and the rhythm pattern.
FIG. 3 shows correlation between the second series' neurons and the rhythm pattern.
FIG. 4 is a block diagram of another rhythm pattern generating instrument embodying the present invention.
FIG. 5 is a graph showing change of the rhythm pattern in use of random numbers generator.
FIG. 6 shows correlation between the neurons and the bass pattern.
FIG. 7 is a block diagram of a bas pattern generating instrument embodying the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, a rhythm pattern generating instrument embodying the present invention is disclosed in detail as follows.
This rhythm pattern generating instrument is provided with a parameter designation operator 1, a normalization part 2, a neural net 3, weighting data memory 4 for storing various weighting data, a weighting data selector 5 for selecting weighting data in the weighting data memory 4, an interpreter 6, an interpretation knowledge memory 7 for storing various interpretation knowledge, an interpretation knowledge selector 8 for selecting interpretation knowledge, an output modifier 9, a modification knowledge memory 10 for storing various modification knowledge, a modification knowledge selector 11 for selecting modification knowledge, a musical playing data synthesizer 12, a key code designation switch 13, and a musical playing part 14.
The parameter designation operator 1 has four volumes, each of which sets a musical parameter. The musical parameters depend on the learning mode of the neural net 3. In the learning mode previously performed, a plurality of data sets of parameters and output data are supplied successively to the neural net 3. It is unnecessary to give basic musical sense to the parameters in the learning mode of the neural net 3. The learning process is usually carried out by use of a back-propagation method.
The parameter designation operator includes an analog-digital converter to output digital values.
The normalization part 2 normalizes the output of the parameter designation operator 1 to use it as input data to the neural net 3. The normalized data is given to each neuron of an input layer of the neural net 3.
The neural net 3 consists of three layers, the input layer, a middle layer, and an output layer. Each neuron of the layers is combined with an adjacent neuron at a certain weighting factor. The number of the neurons of the input layer is equal to the number of parameters of the parameter designation operator 1. The number of the neurons of the middle layer is decided depending on a degree of the learning. In this example, the number of the neurons of the middle layer is twenty.
The number of the neurons of the output layer is decided depending on time resolution of the neural net 3. In the case of M bars output at Nth note notch, the number of notes is equal to N*M per one channel. In the example, notes of a bass drum tone color and a hi-hat tone color are generated at the first channel: notes of a snare drum tone color and a tom tom tone color are generated at the second channel. As time resolution is in a notes pattern of one bar with sixteenth note are generated, the output layer needs 32 neurons (16*1*2(channels)=32).
The weighting data memory 4 stores a plurality of weighting data to comply with different music genre.
The weighting data selector 5 is operated by the performer to select a weighting data in the memory 4.
The interpreter 6 is used to interpret the value output from the neural net 3, thereby changing the value to musical feeling data, using the interpretation knowledge stated later. In this example, each output neuron is independent, not combined with the other output neurons.
The interpretation knowledge stored in the interpretation knowledge memory 7 is used to realize adjustment to some musical genres. In this example, a plurality of sets of the interpretation knowledge is stored in the memory 7.
The interpretation knowledge selector 8 is used to select one interpretation knowledge from the memory 7. The selector is operated by a performer.
The output modifier 9 is used to modify the output value of the interpreter 6 using the modification knowledge in the memory 10, thereby changing musically unacceptable values to musically acceptable values.
The modification knowledge stored in the modification knowledge memory 10 is used to realize adjustment to the musical genres. In this example, a plurality of modification knowledge sets is stored in the memory 10.
The musical playing data synthesizer 12 generates the actual musical playing data according to the output data from the output modifier 9.
The key code designation switch 13 is used to assign a key code to the output data from the output modifier 9.
The musical playing part 14 is an output device, such as an MIDI device, to actually output the musical playing data.
The following is a description of the operation of the above-mentioned rhythm pattern generating instrument.
Step 1--Initializing
The performer arbitrarily inputs parameters in the parameter designation operator 1 by use of the four volumes. Of course, the learning mode is, at this time, already carried out by the neural net 3.
The performer operates the weighting data selector 5 to input any weighting data in the memory 4 to the neural net 3 so as to match the output rhythm pattern to the playing song played by another instrument. The performer also operates the interpretation knowledge selector 8 to input any interpretation knowledge in the memory 7 to the interpreter 6 so as to match the output rhythm pattern to the playing data played by another instrument. Further, the performer operates the modification knowledge selector 11 to input any modification knowledge in the memory 10 to the output modifier 9 so as to match the output rhythm pattern to the playing data played by another instrument.
Step 2--Input to neural net
The parameters inputted by the parameter designation operator 1 are normalized with the normalization part 2, and transferred to the input neurons of the input layer in the neural net 3.
Step 3--Calculating in neural net
First, the values of the neurons of the middle layer are calculated using the weighting data specified by the selector 5. Next, the values of the neurons of the output layer are calculated using the values of the middle layer. ##EQU1##
Step 4--Interpretation of output neurons
The values of the output neurons are modified using the selected interpretation knowledge so as to have the musical sense. The output neurons of the output layer are interpreted on time series. In the example, a set of sixteen neurons beginning from the first neuron in the output layer forms the first series, the remainder of another sixteen neurons forming the second series. Output data of each neuron corresponds to a sixteenth note. In neural net theory, the value of the neurons should be a real number of 0 to 1. However, the real number value is changed to integer value of 0 to 127 for convenience of calculation.
For example, the output neurons' values are interpreted as follows:
The first series (see FIG. 2):
______________________________________Output neurons' value: Interpreted value:______________________________________0 to 5 ungenerating tone 6 to 31 hi-hat-close32 to 56 hi-hat-open57 to 63 bass drum (weak)64 to 69 bass drum (strong)70 to 95 hi-hat-close +bass drum (strong) 96 to 127 hi-hat-open +bass drum (strong)______________________________________
The second series (see FIG. 3):
______________________________________Output neurons' value: Interpreted value:______________________________________ 0 to 18 ungenerating tone19 to 37 low tom38 to 41 snare drum (weak)42 to 60 middle tom61 to 64 snare drum (weak)65 to 83 high tom84 to 87 snare drum (weak) 88 to 127 snare drum (strong)______________________________________
The velocity of the hi-hat, snare drum, and each tom are decided according to the neuron's value.
FIG. 2 and FIG. 3 show correspondences between the first series and the rhythm pattern, and the second series and the rhythm pattern, respectively. The numbers 0 to 31 represent the output neuron's number.
Step 5--Output modification
In this step, the interpreted data (value) output from the interpreter 6, is modified to the value which can be musically accepted using the selected modification knowledge in the memory 10. For example, if a tone is generated at the timing corresponding to the back beat of sixteenth beat in an eight beat music score, the modification is done so that the back beat is released. Furthermore, If the hi-hat will keep open state after interpretation, the hi-hat is closed without open.
Step 6--Synthesizing playing data
The modified data output from the output modifier 9 is represented with velocity value of the tone color (i.e., an instrument name, such as hi-hat, bass drum). The key code switch 13 gives a key code of the tone color to the synthesizer 12 to change it to the musical playing data which can be actually performed. The musical playing part 14 receives the data from the synthesizer 12 and performs the musical playing data.
As mentioned above, adjusting the volume of the parameter designation operator 1 allows various rhythm patterns to be outputted.
FIG. 4 is another example of the present invention.
The rhythm pattern generating instrument shown in FIG. 4 is provided with a group of random numbers generators 1a. The rhythm pattern generating instrument differs from the example shown in FIG. 1 in that this instrument is provided with a group of random numbers generators 1a, a random numbers selector 1b for selecting the random numbers generator, a previous parameter memory 1c, and an adder 1d.
The group of random numbers generators 1a is configured with a plurality of random numbers generator each of which generates digital random numbers with different distribution. The random numbers selector 1b is provided for selecting one random numbers generator in the group of the random numbers generators 1a. The previous parameter memory 1c stores previously used parameters which were used as input data to the neural net 3.
The adder 1d is used to add the value of the previous parameter memory 1c to the output value of the random numbers selector 1b to form a new parameter. This new parameter is stored into the previous parameter memory 1c as a previous parameter for the next time.
The normalization part 2 and the other parts, such as the neural net 3, and weighting data memory 4, are the same as the instrument in FIG. 1.
The following is a description of the process of the above-mentioned instrument.
Step 1--Initialization
A performer arbitrarily inputs initial parameters into the previous parameter memory 1c, and then, selects a random numbers generator to get rhythm patterns changing as expected.
The performer operates the weighting data selector 5 to input any weighting data in the memory 4 to the neural net 3 so as to match the output rhythm pattern to the playing song played by another instrument. The performer also operates the interpretation knowledge selector 8 to input any interpretation knowledge in the memory 7 to the interpreter 6 so as to match the output rhythm pattern to the playing data played by another instrument. Further, the performer operates the modification knowledge selector 11 to input any modification knowledge in the memory 10 to the output modifier 9 so as to match the output rhythm pattern to the playing data played by another instrument.
Step 2--Input to neural net
The output of the adder in which the value of the previous parameter memory 1c is added to the output value of the random numbers selector 1b is fed to the normalization part 2 to normalize it. The output is also supplied to the previous parameter memory 1c to be stored as a previous parameter for next time. Therefore, if the selected random numbers generator distributes numbers non-uniformly, the parameter outputted from the adder 1d is shifted gradually from the first parameter given by the performer.
The process in the neural net 3 and the other processes in the example are the same previously stated in step 3 to 6.
This example is characterized in that the rhythm output pattern, once initialized, is automatically changed without a performer's operation because the input patterns change with the random numbers, so that various trends of the rhythm patterns can be made using random numbers having different characteristics (distribution). For example, if random numbers distributed between -4 and +3 are added successively to the previous parameter in the memory 1c for every bar, parameter (number) is gradually decreased. In experiment, the parameter approximately decides a property of rhythm as follows,
______________________________________parameter (number) rhythm______________________________________0 to 40 eight beats50 to 70 sixteen beats80 to 100 sixteen back beats______________________________________
so that if the process is advanced using the random number distributed between -4 and +3, i.e., the random number offset to a minus, after "100" is stored in the memory 1c as the first parameter, the parameter is gradually decreased, and then the rhythm pattern becomes a less tones pattern, the phenomenon of the rhythm pattern's change images a performer who is tired from playing a drum. While, if the parameter reaches "0" and underflow occurs, the parameter is increased gradually, the phenomenon of the rhythm pattern change images a performer who is getting well. FIG. 5 shows this state. If another type of random numbers is used, another pattern characteristic is obtained.
As another example, it is possible to input parameters for outputting a bass pattern from the parameter designation operator 1. In this case, the neural net 3 is learned so that the input parameters correspond to bass patterns, and the other elements, such as the interpretation knowledge, are properly configured.
The correlation between the output value of the neural net 3 and the bass tone is as follows:
______________________________________Output neuron's value (0 to 1): Bass tone:______________________________________0.00 to 0.35 ungenerating tone (keep previous tone)0.35 to 0.45 root tone (C)0.45 to 0.55 third tone (E)0.55 to 0.65 fourth tone (F)0.65 to 0.75 fifth tone (G)0.75 to 0.85 sixth tone (A)0.85 to 0.95 seventh tone (B)0.95 to 1.0 octave (C)______________________________________
FIG. 6 shows a score according to the abovelisted correlation. The output modifier 9 is used to modify the output data from the interpreter 6 so as to be musically accepted. For example, any discordant tone is deleted or modified, and the rhythm is modified.
As the bass pattern outputted from the output modifier 9 is represented with an interval from a root tone of a chord, or with a tone pitch in "C" chord, it is necessary to change the tone pitch of the bass pattern according to the chord progress of music. This change performance is carried out by the musical playing data synthesizer 12 and a chord designation switch 13. FIG. 7 shows a block diagram of the above-mentioned example. In this diagram, the chord designation switch is different from the switch in FIG. 1.
Even if there is the same image music, an ideal bass pattern or a rule of the music is different depending on the music type. Therefore, the weighting data, the interpretation knowledge, and the modification knowledge are manually or automatically switched according to the music type. The key code can be inputted in a real time mode from the key code designation switch 13.
In this example, one bar of four beats is divided into sixteen, a bass tone being outputted at each timing. It is possible to generate bass patterns fully musical in an instrument arranged so as to be able to output bass tones for two bars, i.e., at each timing of thirty two timings.
As mentioned above, the neural net 3 not only plays back the learned patterns, but also generates middle patterns between two learned patterns, resulting in output patterns that give variety. Also, selecting the weighting data makes variation of velocity or the like, so that generated patterns give variety of rising and falling pitch, diminuendo and crescendo, and so on.
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An electronic musical instrument utilizing neural nets comprises parameter input device for inputting a parameter and a neural net device for calculating the parameter. The neural net device is in advance learning therefore, any input parameter results in proper output by interpolation. The instrument further comprises a weighting data memory, the weighting data being provided to the neural net device. The output of the neural net device is interpreted by an interpreter using interpretation knowledge stored in a memory, thereby the output of the neural net device being changed to musical values. Further, the musical values are modified by an output modifier using modification knowledge stored in another memory so as to be accepted musically. The weighting data, the interpretation knowledge and the modification knowledge can be selected by use of selectors, thus use of the selectors expands musical variation.
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PRIORITY CLAIM
[0001] In accordance with 37 C.F.R. 1.76, a claim of priority is included in an Application Data Sheet filed concurrently herewith. Accordingly, the present invention claims priority to U.S. Provisional Application No. 61/980,987, entitled “Traffic Signal Display and Method”, filed Apr. 17, 2014, the contents of which are incorporated herein in their entirety.
FIELD OF THE INVENTION
[0002] A device and method for displaying a public safety message, an advertisement, or information at a traffic control signal.
BACKGROUND OF THE INVENTION
[0003] The operation of traffic control signals has become increasingly sophisticated. Traffic signals can include such things as traffic control lights, crosswalk lights and the like. Many traffic signals are now controlled by computers to time the operations of the various signals they provide such as green, yellow and red lights. The timing of such operations can be determined by the time of day or night, weather conditions, traffic conditions, overrides from emergency vehicles, pedestrians and the like. Such changes in operations can be highly variable and relatively instantaneous.
[0004] One example of traffic signal control is the crosswalk override. In this case, a pedestrian can activate a signal device, such as a pushbutton switch, to indicate to the traffic signal controller that they would like to cross the street. The computer, in accordance with preprogrammed instructions, can then turn a traffic light from green to red and turn on a crosswalk light indicating that the pedestrian can cross the street while the car traffic light is red. Such a system can be located at an intersection or an area of the road where there is no intersection but only a crosswalk.
[0005] Another form of traffic signal override can be located at an intersection that normally allows the major road to constantly have a green light. A minor road at the intersection can have a vehicle sensor that senses the presence of a vehicle at the intersection wishing to enter the major road. The minor road users encounter a normally red light which needs to change to green while the major road light needs to be changed to red. In accordance with preprogrammed instructions, the traffic signal, once it receives a signal from the minor road sensor, will change the lights so that the vehicle on the minor road can safely enter or cross the major road.
[0006] Traffic control thus results in people spending unproductive time waiting at traffic signals. It would be desirable to provide such people with useful information during a wait period. However, the presentation of such useful information needs to be timed appropriately to the operation of the traffic signal. This is desirable so that an entire message can be appropriately delivered to the people in a timely manner.
[0007] However, the elapsed time for displaying such information is a variable and occurs at different times of day. Thus, there is presented the problem of how to display information at a traffic signal in a useful manner.
SUMMARY OF THE INVENTION
[0008] Generally, the present invention provides a system and method for displaying information at a traffic signal. The system includes a computer system coupled to the computer system controlling the traffic signal to time the display of information on a separate monitor located adjacent a traffic signal. The displayed information can include such things as advertising, notices of public interest such as an Amber alert, and/or upcoming traffic conditions. The timing of the displayed information is such as to not interfere with attention needed for a person to navigate through the traffic signal.
[0009] It is therefore an objective of the present invention to provide a display device which can be used to effectively and timely deliver messages or information of interest to people and/or vehicles while waiting at traffic signals.
[0010] It is a further objective of the instant invention to provide a method which can be used to effectively and timely deliver messages or information of interest to people while they wait at traffic signals.
[0011] It is a further objective of the instant invention to provide a means to time the delivery of information at a traffic signal to effectively utilize the time available for delivery of one or more messages when the available time can vary in a preprogrammed manner or a random manner as controlled by a computer coupled to the traffic signal.
[0012] It is yet another objective of the instant invention to provide a system capable of selecting one or more information segments from a database of information segments to be displayed to fit within a variable time period.
[0013] Other objects and advantages of this invention will become apparent from the following description taken in conjunction with any accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
[0014] FIG. 1 is a schematic illustration of a system adapted for displaying information on a monitor at a traffic signal controlled by a computer system;
[0015] FIG. 2 is a flowchart showing schematically operation of a system for displaying information at a traffic signal;
[0016] FIG. 3 is a schematic illustration of a traffic signal system at a road intersection;
[0017] FIG. 4 is a flowchart illustrating the operation of the present system and method for displaying information at a traffic signal; and
[0018] FIG. 5 is a flowchart illustrating an alternate embodiment of a system for displaying information at a traffic signal incorporating voltage sensor(s) on the traffic lights.
DETAILED DESCRIPTION OF THE INVENTION
[0019] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred, albeit not limiting, embodiment with the understanding that the present disclosure is to be considered an exemplification of the present invention and is not intended to limit the invention to the specific embodiments illustrated or disclosed.
[0020] Referring to FIGS. 1-3 , an intersection, designated generally 1 , is shown as a four-way intersection, i. e., two roads designated 2 and 3 that intersect. Each of the roads 2 and 3 is shown as being controlled by a signal device designated generally 5 A-D. It is to be understood, however, that the invention can be used at any type of intersection controlled by any suitable signal device. Typically, a signal device 5 A-D is stoplight operable to display lights of different colors, typically red, yellow and green, to indicate permissible movement of traffic. Turn control signals may also be provided as well as pedestrian control signals. Such traffic control systems are well known in the art. Such control systems can be computer-controlled to allow for changes in their operation to accommodate time of day, changes in traffic pattern, overrides by emergency vehicles from an input device such as a remote transmitter 7 , traffic sensors 6 and pedestrians through operation of an override button 8 as known in the art. By way of example, during a so called rush hour, the vehicles 4 on the road 2 may be given more priority than vehicles 4 on cross road 3 through longer green lights provided for the users of road 2 . Traffic sensors 6 can be utilized on a low usage road 3 to send a signal to a signal system 10 ( FIG. 1 ) to indicate that there is cross traffic and allow its controller 11 to change the lights on signal devices 5 B and 5 D to red and the lights on signal devices 5 A and 5 C to green to allow vehicles 4 on road 3 to cross road 2 . By way of further example, a pedestrian can activate the override button 8 when they wish to cross at the crosswalk 12 . This provides a signal to the controller 11 which will then, when permitted by its programming, change the lights 5 B and 5 D to red allowing the pedestrian to then cross road 2 . Crosswalk lights 14 can be provided at the intersection 1 which are operable to indicate to a pedestrian that it is permissible or not permissible to cross the road 2 . Such traffic signals and their operation are well known in the art. While the invention is described in terms of roads for motorized vehicles, it can also be utilized for pedestrian and non-motorized vehicle roads (often referred to by other names such as paths and trails).
[0021] As shown, the signal system 10 includes various input devices such as the transmitter 7 , traffic sensor 6 and pedestrian override button 8 . The system 10 also includes output devices such as the signal devices 5 A-D and a computer system 19 as described below. The controller 11 , as shown, includes the computer system 19 and the various input devices 6 - 8 .
[0022] The present invention can be an addition to an existing traffic signal control system 10 . However, it is to be understood that traffic control systems 10 can have portions of the present invention integrated into the control system 10 , allowing for the use of a single controller. The present invention will, for convenience, be described in terms of a separate control system coupled to an existing control system 10 .
[0023] The display system, designated generally 15 , includes a computer system 17 coupled to a computer system 19 , FIG. 1 . The computer system 17 is operable to function as a controller to control operation of the display system 15 , while the computer system 19 controls operation of the traffic control system 10 . The computer systems 17 , 19 are programmed for effecting desired operation of the respective display system 15 and traffic signal devices 5 A-D, 14 . The traffic control system 10 is dominant to the display system 15 and provides information thereto by coupling of the computer systems 17 and 19 . This coupling can be wireless or hard wired. The computer system 19 provides its operational information to the computer system 17 so that the computer system 17 can control operation of the display system 15 . The computer system 17 includes both a digital processor 21 and a memory 22 . The computer system 19 also includes both a digital processor 24 and memory 25 . The computer system 19 is programmed to control operation of the output devices, such as the signal devices 5 A-D, 14 . The computer system 17 is programmed to receive information from the computer system 19 , process the received information and effect operation of the display system 15 with its output device 30 . A preferred output device 30 is a display monitor such as an LED screen or the like operable to visually display selected information. It should be noted that while the present disclosure discusses the display system as having a display monitor, the present invention also contemplates multiple monitors which may include screens which can only be viewed from predetermined angles and the like, to provide the information to persons or vehicles positioned in predetermined areas while preventing the viewing by other persons or vehicles.
[0024] The operation of the control system 10 can be such as to change the signals displayed by the signal devices 5 A-D; for example, during heavy traffic periods which can be preprogrammed in the memory 25 for allowing traffic on road 2 to get longer green lights and more frequent green lights. This preprogrammed sequence can be adjusted by information received from the sensors 6 , for traffic on the road 3 . This adjustment can be made pursuant to preprogrammed instructions, e.g. algorithm, contained in the memory 25 . A temporary adjustment can be made to the operating sequence by operation of the pedestrian override button 8 or an emergency vehicle sending a signal via transmitter 7 , received by the computer system 19 .
[0025] The computer system 19 , through its programming, controls the duration of a red, green and/or yellow light of stoplights by providing control signals to various switches to turn the switch on or off. These control signals are communicated to the computer system 17 through the coupling of the two computer systems 17 , 19 . The control signals to the computer 17 alert it to the current operation of the signal devices 5 A-D. This information is processed by the processor 21 in accordance with instructions programmed in the memory 22 . The computer system 17 is programmed to process the received control signal information and time various output operations of the display system 15 .
[0026] The display system 15 includes the output device 30 which receives information from the computer system 17 that can be displayed as preprogrammed. Information for displaying is preferably stored in the memory 22 . Such information can include highway conditions that can be received from various sensors similar to the aforementioned sensors 6 . These sensors can provide weather data, road conditions, traffic data and the like. Information for display can also include such things as Amber alerts and adverse traffic conditions which can be transmitted to the computer system 17 wirelessly or by a hard wire, and can be given a priority for display as preprogrammed. The information stored for display or received for display will have a time duration. The computer system 17 can be programmed to select various information segments, e.g., various advertisements, public safety messages, information etc., either individually or in combination of separate information files, and through programming can select appropriate information for display by time of day and duration for display to fill the time period available for display, say for example the length of time the red light will be on, which would allow a person stopped at the intersection to view one or more complete information segments. For example, a breakfast ad can be shown during morning hours while dinner ads can be shown during afternoon and evening hours, and could be followed by a car ad segment which is not time of day sensitive. A tabulation of the information displayed can be accumulated in a database in the memory 22 for accounting and billing purposes for information displays that can be charged to an entity for the display. In at least one embodiment, the information regarding information displayed may be transferred directly to a command center for billing the customer for the ad displayed. The system can also be utilized to warn viewers when an emergency vehicle is approaching should the emergency vehicle provide a signal from the transmitter 7 indicating the necessity to stop traffic and allow safe entry into the intersection. The programmed instructions can determine what information segments are shown and when, avoid conflicting information being displayed in one display period, for example, two sequential competing restaurant ads.
[0027] The computer system 17 can be programmed to cease operations or change its operations in the event of a malfunction of the control system 10 . For example, if the controller 11 is calling for a flashing red light, information displayed on the monitor 30 can be terminated or different types of information can be selected from information segments in the memory 22 that are more appropriate for short stays at the intersection. Information stored in memory 22 can be changed from time to time by coupling of the computer 17 to another memory, either by wire or wireless and can be done from a remote location.
[0028] A preferred method of operation sequence is illustrated in FIG. 2 . Operating information 51 for the traffic signal system 10 is transmitted to the display system 15 . This information 51 can include time of day, day of week, date, and traffic signal duration and selection (e.g., red, green, yellow, flashing, etc.). The operating information 51 is transmitted to the computer 17 at 53 . It is to be understood that some of the just mentioned information can already be known by the computer 17 , e.g., time of day, day of week and date. The computer system 17 processes the information at 55 and selects information segments, at 57 , appropriate for display, given programmed criteria, to effectively utilize the available time for displaying the selected information on the output device 30 . Such information can be displayed on the output device 30 during a red light period. Selection of the information segment for display can include prioritization criteria 59 , including time needed to complete the segment, or segments, as compared to time available 61 , and other criteria such as time of day, day of week, date, etc. 63 . The computer system 17 can also give priority to emergency information 65 . The selected information segment or segments is then displayed at 67 . In the event of an emergency prioritization, the computer 17 can select to display information during more than just the red light period, so that the emergency message is visible to all passing motorists, pedestrians, bicyclists, etc. Prioritization of non-emergency segments can be based on agreements with companies based on various times of day which correlate to different volumes of traffic.
[0029] FIG. 4 shows the underlying operation leading to the operation sequence illustrated in FIG. 2 . Within the traffic system computer system 19 , the signal controller executes an event cycle at 32 . During operation, the controller causes the output device 30 to display the executed ad segment at 34 . While this occurs, the controller checks for a signal malfunction 36 . If a signal malfunction is detected, the controller terminates the ad segment being displayed at 38 . If no signal malfunction is detected, and until one is detected, the controller will execute the software sequence to display the ad segment at 34 . While the ad segment is processing, the controller keeps track of the traffic signal cycle. If the signal cycle is pre-determined, where the red-light period of time is known as a fixed period upon initiation of the red-light, then display output can include a timer showing how much time is left for the red-light period. When the signal controller completes the red-light cycle at 40 , the controller will pause the ad software sequence at 42 , to be resumed upon the next red-light cycle. Alternatively, two or more signals may be connected to form a network whereby the ad sequence may be continued to the next signal light along the vehicles path. In this embodiment, the networked signal lights may also include internet transmitters for the creation of an internet network between the signals.
[0030] In one embodiment, the display system 15 can include a sensor 28 for recognition of vehicles or cellular telephones. Sensor 28 can be based on RFID technology, GPS, Bluetooth, Wi-Fi, or similar known technologies which can be incorporated into the output device 30 , or other structure within the display system 15 . Alternatively, the sensor can be positioned within the existing signal pole, as well as within the pedestrian override button 8 , so that pedestrian traffic is also identified.
[0031] By connecting with a vehicle computer, or a cellular phone, the display system 15 is able to identify and catalog the amount of viewers present during the display of each ad segment. Incorporating a secondary software application, the display system 15 can link with the vehicle computer, cellular phone or radio frequency identification (RFID) chip or sticker and provide supplemental advertisements or coupons related to the ad segments displayed to the viewer, or which relate to businesses in the vicinity.
[0032] Further uses of sensor 28 can be to help locate specific vehicles or cellular phones, such as during Amber alerts, or similar situations. Law enforcement would also benefit from being able to quickly and efficiently track or find a person or vehicle. The system can also be used to display traffic control signs on a portion of the screen in the event that the local police force needs to control traffic for events or other high traffic issues.
[0033] A game system can also be tied into the present invention. For example, with the game system, a treasure-hunt type game can be implemented where a driver can collect points, coupons or the like, by passing through specified intersections. In some games, clues may be provided as the communication capable vehicle or cell phone passes through an intersection directing them to the next intersection of the game.
[0034] In an alternate embodiment, illustrated in FIG. 5 , a voltage sensing unit is employed when it is not possible or feasible to directly connect the display system computer to the traffic signal computer. This embodiment then needs to connect directly to the traffic signal lights. The voltage sensing unit senses the voltage being employed by the individual red, yellow, and green lights of the traffic signal to determine at 74 whether: the red light is on, off, or blinking 70 ; the yellow light is on, off, or blinking 71 ; and the green light is on, off, or blinking 72 . Based on the activation of the lights, the voltage sensing unit transmits the signal to the microcontroller at 76 which triggers the computer at 78 to execute the appropriate software segment. With this method, the display computer will not be able to display the remaining time of the red light cycle, or time the ad segment or segments to the amount of time of the red light cycle; the computer can execute the ad segment during a red light cycle and pause the program when the voltage sensing unit senses that the red light is off. The green and yellow light sensors help provide the complete picture of what is occurring at the intersection, so that the display computer can select the appropriate executable ad sequence. In at least one embodiment, the voltage sensing unit is added to one of the other embodiments described herein to provide a safety factor whereby the display system is shut down when one or more of the signals lights are not functioning properly. This construction eliminates confusion to drivers who may see an advertisement but no traffic signal light.
[0035] It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.
[0036] One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.
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The present invention provides a system and method for displaying information at a traffic signal. The system includes a computer system coupled to the computer system controlling the traffic signal to time the display of information on a separate monitor located adjacent a traffic signal. The displayed information can include such things as advertising, notices of public interest such as an Amber alert, and/or upcoming traffic conditions. The timing of the displayed information is such as to not interfere with attention needed for a person to navigate through the traffic signal.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to computer peripheral devices, and particularly to an improved computer pointing device with a gain control device to swiftly adjust the resolution of cursor movement.
2. Background
Pointing devices are commonly used today in conjunction with software to position a computer cursor and to control the functioning of a computer. The computer cursor moves in relation to the movement of the pointing device under software control. Typical of such a pointing device is a computer mouse. The computer mouse is a hand-operated device that requires the user to remove his or her hand from a keyboard whenever the position of the cursor needs to be changed. Like all hand-operated pointing devices, the mouse can also be restricting to users with limited range of hand movement.
Experiments have been done with feet operated pointing devices that perform identical functions to the mouse. Such a device is commonly referred to as a "mole." Still other pointing devices can be operated with the eye, head or body parts other than the hand. However, all technologies that do not use the hand to operate the pointing device tend to suffer from the disadvantage that the small motor skills of the hand are better than those of other parts of the body. In other words, the hand-operated mouse allows the user to position the cursor more accurately than other pointing devices. This is not to say, however, that the positioning precision of the mouse cannot be improved.
It is therefore the object of the present invention to provide a method and apparatus for an improved computer pointing device that enhances cursor positioning precision and range of motion. It is further the object of this invention to provide an apparatus for making computer operation more efficient.
SUMMARY OF THE INVENTION
In the present invention, a computer peripheral device for providing a computer with signals that control the movement of a computer cursor is taught utilizing a gain control means, wherein gain is defined as the ratio of cursor movement along the y-axis and x-axis relative to the corresponding amount of movement by a pointing means along the y-axis and x-axis. The computer peripheral device comprises the pointing means and the gain control means. The pointing means provides coordinate input signals in response to detected movement of the pointing means. The gain control means provides gain signals which can then be used to scale the coordinate input signals. In one embodiment of the invention, the gain control means includes a variable resistor and a foot pedal mechanism. The variable resistor comprise of a resistance that is manipulable by the foot pedal mechanism for varying the magnitude of the gain signals emanating from the gain control means. The computer peripheral device can also include a plurality of switches for transmitting switch state signals indicative of commands corresponding to the current position of the computer cursor.
The coordinate input signals, gain signals and switch state signals are receivable by a first processing means. The first processing means performs one of two functions: process the signals or send it to a second processing means for processing. Regardless whether the signals are processed by the first or second processing means, the result is the output of scaled coordinate input signals in a form simulating a mouse output. In the preferred embodiment, the processing means first determines a gain value from the gain signals and scales the coordinate input signals as a function of the gain value to arrive at the desired output, i.e., scaled coordinate output signals in a form simulating a mouse output. Includable in the output are the switch state signals.
Advantageously, the present invention is also a computer peripheral device, to be used in combination with a pointing means, that provides gain signals to the processor for swiftly adjusting the resolution of cursor movement. This computer peripheral device is coupled to a processor and comprises a gain control means and an output means. The gain control means permits users to manipulate the magnitude of the gain signals. The output means is coupled to the gain control means and transmits the gain signals from the gain control means to the processor. In the preferred embodiment, the gain control means includes a variable resistor having a manipulable resistance for varying the magnitude of the gain signals and the output means is a analog/digital converter that transforms the gain signals into digital form. A buffer amplifier can be interposed between the variable resistor and analog/digital converter to provide proper input to the analog/digital converter. The computer peripheral device can include its own processing means for receiving the gain signals from the output means and the coordinate input signals from the pointing means. The processing means will either transmit the received signals in its original form to another processing means for processing or process the signals itself to output scaled coordinate input signals in a form simulating a mouse output.
Also in accordance with the present invention is a method for facilitating the movement of the computer cursor utilizing a gain control means for increasing user control over a pointing means. This comprises the steps of receiving a first and second set of coordinate input signals from the pointing means; determining an amount of change along the y-axis and x-axis from the first and second set of coordinate inputs signals; receiving gain signals from the gain control means; calculating a gain value using the gain signals; and scaling the amount of change along the y-axis and x-axis as a function of the gain value. The method can also include the step of manipulating the gain control means to vary the magnitude of the gain signals. Manipulation of the gain control means can be accomplished by depressing and releasing a foot pedal mechanism. Upon scaling the coordinate input signals, the method can also include the step of outputting the scaled amount of change along the y-axis and x-axis in a form simulating a mouse output.
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram depicting an embodiment of the present invention;
FIG. 2 is a graph depicting an example of a relationship between the amount of gain and hexadecimal value for the gain signal;
FIGS. 3 and 4 are flowcharts depicting an example of a processing means for transforming the serial stream to simulate a computer mouse;
FIG. 5 is a flowchart depicting an example of a sig -- alarm routine that executes upon the occurrence of an interrupt;
FIG. 6 is a flowchart depicting an example of a mouse routine for the Logitek® mouse referenced in FIGS. 3 and 4;
FIGS. 7, 8 and 9 are the flowcharts depicted in FIGS. 3 and 4 with embedded alarms routine; and
FIG. 10 is a side view of a foot pedal mechanism for varying the gain signal from the gain control device in FIG. 1.
DESCRIPTION
As shown in FIG. 1, a hands-free mouse unit 02 is connected via a serial line 06 to a first serial port 14 in a computer 04. The hands-free mouse unit 02 transmits cursor position signals to the computer 04 and comprises a pointing device 20, a gain control device 30, a plurality of pushbuttons 40 and a processor 50. The hands-free mouse unit 02 transmits signals which are subsequently converted by a processing means within the computer 04 in a form simulating a mouse output and later transmitted by the processing means to a mouse port 16 in a keyboard 10 connected to the computer 04 where it is subsequently processed by a mouse driver program.
The pointing device 20 can be any number of products that provides coordinate input signals indicating an amount of movement along the y-axis and along the x-axis in response to physical movement of the pointing device 20. Note that some pointing devices 20 provides coordinate input signals indicating changes in pitch (i.e., elevation) and yaw (i.e., azimuth) which may be converted to a corresponding amount of movement along the y-axis and x-axis. Typical of pointing devices are mice, track balls, moles, eye-tracking technology, joysticks and position trackers, such as mechanical, optical, magnetic and acoustic. Such devices and their technology are well known in the art.
In the preferred embodiment of the invention, the pointing device 20 employed is an alternating current magnetic position tracker manufactured by Polhemus called 3Space® Isotrak®. The 3Space® Isotrak® comprises a source 22, a sensor 24 and a control unit 26. The source 22 is constructed of three mutually perpendicular emitter coils, not shown, that generate three perpendicular rotating magnetic fields. The sensor 24 is constructed of three mutually perpendicular sensor coils, not shown. The three magnetic fields generated from the source 22 induce three currents in each of the sensor coils. The current induced in each sensor coil will vary depending on its distance and angle from the source 22. This provides a basis for the control unit 26 to calculate relative pitch and yaw values. These values are subsequently transmitted from the control unit 26 to the processor 50. The pitch and yaw values are then used to calculate a corresponding amount of movement by the 3Space® Isotrak® along the y-axis and x-axis, respectively. The calculation process comprises the following steps: (1) determining Δpitch and Δyaw, which are the difference between a first and second set of pitch and yaw values, respectively; and (2) multiplying the sine function for Δpitch and Δyaw against a predetermined distance D (i.e., the distance the sensor 24 is assumed to be from a computer monitor, not shown). The above briefly described magnetic position tracker technology is well known in the art. In one embodiment of the invention, the sensor 24 is placed on a user's head for hands-free operation. By varying the angle of the head, the user can manipulate the cursor on the computer monitor.
To increase user control over any pointing device 20, the present invention includes a gain control device 30. "Gain" is defined as the ratio of cursor movement along the y-axis and x-axis relative to the corresponding amount of movement by the pointing device 20 along the y-axis and x-axis. The gain control device 30 includes, but is not limited to, one of the following devices that permits users to manipulate the magnitude of a gain signal: an optical shaft encoder; an accelerometer; an electrolytic inclinometer; a pressure gauge; a strain gauge; a photocell and light source that are moved together or apart.
One embodiment of the gain control device 30 comprises the following electrical components coupled in series: power supply 32 to fixed resistor 34 to variable resistor 36 to buffer amplifier 38 to analog/digital converter 39. The gain control device 30 outputs to the processor 50 a voltage signal in binary digit form. In this embodiment, the voltage signal is used as the gain signal. By varying the resistance of the variable resistor 36, the user can swiftly control the magnitude of the voltage fed to the buffer amplifier 38. The buffer amplifier 38 is designed with a high input impedance and low output impedance to minimize the load on the variable voltage and to provide ample "drive" for the analog/digital converter 39. The buffer amplifier 38 transforms the voltage signal into a low input impedance for the analog/digital converter 39 where it is subsequently output in binary digit form to the processor 50 and later used for calculating a gain value.
The preferred embodiment of the invention utilizes a foot pedal mechanism 37, as shown in FIG. 10, to vary the impedance of the variable resistor 36 for hands-free operation. The foot pedal mechanism 37 comprises an upper portion 37a, a lower portion 37b, a spring 37c and a hinge 37d. The upper portion 37a and lower portion 37b are hinged to each other at or near point A by the hinge 37d and are separated at point B by the spring 37c, which is interposed between the upper portion 37a and lower portion 37b, allowing the foot pedal mechanism 37 to move between an up and down position. The variable resistor 36 is positioned within the foot pedal mechanism 37 in a manner permitting the user to vary the resistance of the variable resistor 36 by manipulating the foot pedal mechanism 37 between the up and down position.
The gain control device 30 permits users to swiftly manipulate the gain of the pointing device 20 so small movements may be easily performed by lowering the gain and fast movements can be quickly accomplished by raising the gain. As mentioned earlier, the resistance of the variable resistor 36 can be varied using the foot pedal mechanism 37. For each position of the foot pedal mechanism 37, there is an associate gain signal. Depressing the foot pedal mechanism 37 increases the resistance and causes an increased gain signal to be transmitted. In the preferred embodiment, the relationship between the gain value and the gain signal (expressed in hexadecimal notation from the analog/digital converter 39) is piecewise linear, as shown in FIG. 2. Other relationships may also be applied. Slight depression of the foot pedal mechanism 37 allows the user to decrease the gain and enhance cursor positioning precision. This compensates for users with poor motor skills. Increased depression of the foot pedal mechanism 37 increases the gain allowing the user to re-position the cursor larger distances quickly with smaller movements of the pointing device 20. This is particularly advantageous for users having a limited range of motion with the body part which operates the pointing device 20. Most users use large gain and small gain settings depending on the amount of movement desired.
Additionally, the relationship in FIG. 2 provides the gain control device 30 with a "clutch" function for re-centering operations. The "clutch" function is akin to picking a conventional computer mouse off the surface and re-centering it without changing the position of the cursor. This gives the user freedom to move the pointing device 20 without re-positioning the cursor. The "clutch" function is accomplished by assigning a gain value of zero to a range of hexadecimal values less than or equal to a predetermined value. This predetermined hexadecimal value is referred to as "minped." As shown in FIG. 2, "minped" is equal to hexadecimal value "0f."
Referring back to FIG. 1, the present invention includes the pushbuttons 40 for supplying various instructions with respect to the current position of the cursor. The pushbuttons 40 are interposed between power supplies 44 and parallel ports 42 of the processor 50 and comprise a resistor 46 and a switch 48 having a positive "on" and a positive "off" position. The switch 48 remains in the positive "on" position unless depressed by the user. In the positive "off" position, a voltage (approximately 5 volts) indicative of switch state is transmitted in the form of a single byte to the processor 50. In the positive "on" position, approximately zero voltage is transmitted. Alternately, keyboard buttons or verbal buttons (used with a word spotting program) could be used to perform the functions of the pushbuttons 40.
The signals transmitted from the pushbuttons 40, control unit 26 and analog/digital converter 39 have associated values and are stored in the processor 50 until they are retrieved by the computer 04. The present invention includes a processing means within the computer 04 operative to execute a program stored in associated memory for retrieving the aforementioned values and then outputting them in the form of a byte array simulating a mouse output. FIGS. 3, 4 and 6 are flowcharts illustrating such a processing means. FIGS. 3 and 4 represent a flowchart of a main routine and FIG. 6 represents a flowchart of a subroutine called by the main routine.
As shown in FIG. 3, the main routine begins by declaring definitions and storage allocations in step 3a and initializing both serial lines 06 and 08 in step 3b. Step 3c marks the beginning of a loop which continuously processes information from the processor 50. This loop executes approximately twenty times per second. In step 3d, the routine transmits a "read" command to the processor 50 and retrieves the current pushbuttons 40 byte values and analog/digital converter 39 hexadecimal value. The current byte and hexadecimal values are saved as "buttons" and "pedal," respectively, in step 3e. Step 3f checks to determine whether the position of pushbuttons 40 have changed since the last execution of the loop by comparing "buttons" to "sbuttons," i.e., previously saved byte values for the pushbuttons 40, and whether the pushbuttons 40 are currently depressed. The value "sbuttons" were initially set to zero in step 3a. If (1) either "buttons" differs from "sbuttons" or "buttons" do not equal zero and (2) if "pedal" is less than or equal to "minped" (which was set in step 3a), then the routine proceeds to step 3g and calls the mouse routine depicted in FIG. 6 to output the byte value as if it was transmitted by a mouse. If either conditions are false, the main routine continues to step 3h.
In the mouse routine, the contents of "buttons" will be input into a byte array. The mouse routine depicted in FIG. 6 outputs a byte array simulating a Logitek® mouse output. It should be understood that other brands of mice could just as easily have been simulated. The mouse routine begins with initialization of the byte array in step 6a. Step 6b proceeds to input the contents of "buttons" into the byte array depending on which pushbuttons 40 were pushed. The mouse routine continues to step 6c where it inputs the values for Δy and Δx. Unless the mouse routine was called by step 4l, the values for both Δy and Δx would be zero. Step 6d outputs the byte array to the computer 04 through the mouse port 16 where the byte array is processed the mouse driver. Control is then returned to the calling routine. Step 3h proceeds to update "sbuttons" with the contents in "buttons" for future reference.
The following sequence of steps deals with the re-positioning of the cursor. In step 3i, a "read" command is transmitted to the processor 50 to retrieve the current values for pitch and yaw. For ease of manipulation, step 4a reformats and sign extends the current pitch and yaw signals as "cpitch" and "cyaw." Step 4b decides whether any action must be performed with the computer cursor based on these values. If "pedal" is less than or equal to "minped," the routine assumes the user is performing re-centering operations and goes to step 4c so it can update the previously saved pitch and yaw values, i.e., "spitch" and "syaw," respectively, with its current values for future reference. The routine is then returned to the beginning of the loop at step 3c. Otherwise "pedal" is greater than "minped" and the routine assumes the user is re-positioning the cursor and proceeds to step 4d.
Step 4d first determines the gain value based on the hexadecimal value of "pedal" and a predetermined relationship between the two values. An example of such a relationship is illustrated in FIG. 2. Step 4d then proceeds to calculate Δy for the computer cursor. The value Δy (or Δx) represents the scaled amount of relative movement along the y-axis (or x-axis). This value is determined by calculating Δpitch, i.e., difference between "cpitch" and "spitch" (or Δyaw, i.e., difference between "cyaw" and "syaw"), converting Δpitch (or Δyaw) to a corresponding amount of movement along the y-axis (or x-axis) and using the gain value to scale the amount of movement. However, "noise" from the 3Space® Isotrak® can create false pitch and yaw readings which will cause the routine to generate a non-zero Δy (and/or Δx) value although the sensor 24 and source 22 are completely stationary. The result is an undesirable oscillating cursor on the computer screen.
One embodiment of the routine includes a low pass filter routine for correcting the "noise" problem and stabilizing the computer cursor by using the average value of Δy instead of the current Δy value. This will stabilize the movement of the computer cursor.
Step 4d first determines whether the user opted to employ the low pass filter routine. If yes, the routine goes to step 4f which calculates an average Δy based on the current Δy and a predetermined number of prior Δy's. The average Δy value will be used to re-position the cursor. The routine continues to step 4g where it sets the maximum Δy, as required by the operating system. Steps 4h-k calculates Δx for the computer cursor in the same manner steps 4d-g calculates Δy.
Upon calculating Δy and Δx (or average Δy and Δx), step 4l calls the mouse routine. The values for Δy and Δx are input into the byte array in step 6c and then output to the mouse port 16 by step 6d causing the cursor to be re-positioned. Control is returned to the main routine where step 4m updates "spitch" and "syaw" with the contents of "cpitch" and "cyaw." The routine is subsequently looped back to step 3c where it can process the next set of signals from the processor 50.
Other versions of the main routine can be embedded with time-out alarms to correct "hanging" problems that may occur when there is no response to the "read" commands in steps 3d and 3i. One such embodiment is shown in FIGS. 7-9. This embodiment utilizes system calls and is executable in an UNIX® operating system. The time-out alarm operates on the principle that the "read" command must be completed within a specified time interval otherwise a system alarm will cause an interrupt to occur. Upon occurrence of the interrupt, a series of programming statements will notify the routine that the time-out alarm had expired. The serial lines 06 and 08 will then be closed and the main routine restarted.
Step 7a begins by initializing the time-out alarm. It instructs the operating system that the routine "sig -- alarm," as shown in FIG. 5, is the routine to execute in the event of an interrupt. Step 7b proceeds to check whether the time-out alarm expired by using "setjmp" to save its stack environment in "read -- alarm" for later use by "longjmp". A value of "0" is always returned in the initial loop. As long as the returned value remains "0" and is not changed by the "sig -- alarm" routine, the time-out alarm is deemed not expired.
If the time-out alarm did not expire, the routine proceeds to step 7d where it sets the system alarm to lapse after a predetermined time interval. If step 3g is timely completed, the routine continues to step 7d where the system alarm is cancelled before the interrupt can occur. Otherwise the system alarm would cause an interrupt.
Upon occurrence of the interrupt, the "sig -- alarm" routine in FIG. 5 is executed. Step 5a of the "sig -- alarm" routine uses "longjmp" to restore the environment saved in "read -- alarm" by the last call of "setjmp." It then causes execution to continue as if the call of "setjmp" had just returned a value of "1." When step 7b later checks the returned value, it will read "1" and conclude the time-out alarm expired. In such an event, the routine proceeds to step 7c and goes to the restart routine in FIG. 9. In steps 9a and 9b of the restart routine, the first and second serial lines 06 and 08 are closed and then the main routine is restarted. Likewise, steps 8a-d are identical in function to steps 7b-e and are used to confirm successful "read" commands for pitch and yaw values in step 3i.
In another embodiment of the invention, the above described processing means is within the processor 50 and the byte array is outputted directly to the mouse port 16 or computer 04.
Although the present invention has been described in considerable detail with reference to a certain preferred version thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred version contained herein.
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There is provided a method and apparatus for an improved computer pointing device. The present invention facilitates positioning the computer cursor and includes a pointing device for providing coordinate input signals and a gain control device for providing gain signals, wherein gain is defeined as the ratio of the cursor movement along the y-axis and x-axis relative to the corresponding amount movement of the pointing device along the y-axis and x-axis. The coordinate input signals and gain signals are received by a processor. The processor is operative to execute a program that scales the coordinate input signals as a function of a gain value determined from the gain signal. The processor then outputs the scaled coordinate input signals in a form simulating a mouse output. The pointing device can be any computer peripheral device capable of providing coordinate input signals indicating an amount of movement along the y-axis and x-axis. The gain control device is any device capable of providing gain signals to a processor. One embodiment of the gain control device includes a variable resistor to manipulate the magnitude of the gain signal. The gain control device can also include an analog/digital converter for converting the gain signal into digital form and a buffer amplifier for providing a low impedance input from the variable resistor to the analog/digital converter. Preferably the gain signals emanating from the gain control device is manipulable by a foot pedal mechanism.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The disclosure of Japanese Patent Application No. 2007-332998 filed on Dec. 25, 2007 including specification, claims, drawings, and abstract is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a level shift circuit for shifting the voltage level of a current signal.
[0004] 2. Description of the Related Art
[0005] In imaging equipment such as a video camera and a digital still camera, there is a requirement for preventing a video image from becoming degraded due to the occurrence of blur in a subject image by vibration and the like, such as by hand shake, and a vibration measurement mechanism is provided. This vibration measurement mechanism detects the vibration of the imaging equipment with respect to the subject, and it is known that, in response to vibration, an optical system (lens) and the like is shift-corrected by a motor and the like (see Japanese Patent Laid-Open Publication No. Hei 07-23277 etc.).
[0006] As this motor for correction, a voice coil motor and the like are used, and to make the driving of this voice coil effective, a power source of preferably high voltage is used.
[0007] Hence, after performing the amplification of the signal for driving with an internal reference voltage, the power source voltage is level-shifted to a battery power source, and as a result the circuit and the like for outputting the signal to the voice coil is adopted as a drive circuit of the voice coil.
[0008] Further, as related literature, Japanese Patent Laid-Open Publication No. 2000-244306 can be cited.
[0009] Here, the battery power source is lowered with use. Depending on the kind of the battery, there are cases where the lowering of the voltage is considerably large. In this case, when the reference voltage internally used is made undependable on the battery power source and unalterable, the reference voltage and the battery power source are sometimes reversed.
[0010] In general, the level-shift circuit is configured such that the relation of magnitude between two power sources that are the object of conversion is fixed, and the relation is not assumed to be reversed. Hence, when the relation of two power source voltages is reversed, there is a problem that the circuit is unable to perform an expected operation.
SUMMARY OF THE INVENTION
[0011] According to the present invention, since the conversion of the power source voltages is performed by a current mirror, the level shift of the signal can be performed regardless of the magnitude of both of the power source voltages.
BRIEF DESCRIPTION OF THE DRAWING
[0012] FIG. 1 is a view showing the configuration of a level-shift circuit of the embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] An embodiment of the present invention will be described below with reference to the drawing.
[0014] FIG. 1 shows a circuit according to the embodiment. An input signal Vin is inputted to the base of a PNP transistor Q 1 via a buffer amplifier BAO. The emitter of this transistor Q 1 is connected with the collector of a PNP transistor Q 2 , and the emitter of this transistor Q 2 is connected to a power source VCC 2 . The base of the transistor Q 2 similarly has the emitter connected with the power source VCC 2 and connected with the base of a transistor Q 3 , whose collector and base are short-circuited. The collector of this transistor Q 3 is connected to the collector of an NPN transistor Q 4 . The transistor Q 4 has the emitter connected to ground, and has the base connected to the base of a transistor Q 5 at the current mirror input side, whose collector and base are short-circuited.
[0015] This current mirror input side transistor Q 5 causes a fixed current I 0 to flow, and all transistors constituting this transistor Q 5 and the current mirror cause this fixed current I 0 to flow. Consequently, all the transistors Q 4 , Q 3 , and Q 2 cause the current I 0 to flow.
[0016] The collector of the transistor Q 1 is connected with the collector of an NPN transistor Q 6 , and this transistor Q 6 has the collector and base short-circuited and has the emitter connected to ground. The base of the transistor Q 6 is connected with an NPN transistor Q 7 , whose emitter is connected to ground, and the collector of this transistor Q 7 is connected to the collector of a PNP transistor Q 8 . The transistor Q 8 has the emitter connected to a power source VCC 1 , and has the base and collector short-circuited. Consequently, the transistor Q 8 causes the same current as that of the transistor Q 7 to flow. The base of the transistor Q 8 is connected with a PNP transistor Q 9 , whose emitter is connected to the power source VCC 1 , and the transistors Q 8 and Q 9 constitute the current mirror. The collector of the transistor Q 9 is connected with the collector of an NPN transistor Q 10 , and the emitter of this transistor Q 10 is connected to ground.
[0017] Consequently, the transistor Q 9 causes the current (I 1 ) flowing through the transistor Q 1 to flow. The difference between the current flowing through the transistor Q 9 and the current flowing through the transistor Q 10 is obtained at a node A 1 which is a connection point of the collector of the transistor Q 9 and the collector of the transistor Q 10 , and this is outputted.
[0018] On the other hand, the signal of a fixed value of (½) VCC 2 is inputted to the base of a PNP transistor Q 21 . The emitter of this transistor Q 21 is connected with the collector of a PNP transistor Q 22 , and the emitter of this transistor Q 22 is connected to the power source VCC 2 . The base of the transistor Q 2 similarly has the emitter connected with the power source VCC 2 , and is connected with the base of a transistor Q 23 , whose collector and base are short-circuited. The collector of this transistor Q 23 is connected to the collector of an NPN transistor Q 24 . The transistor Q 24 has the emitter connected to ground, and has the base connected to the base of the current mirror input side transistor Q 5 , whose collector and base are short-circuited.
[0019] This current mirror input side transistor Q 5 causes the fixed current I 0 to flow, and all transistors constituting this transistor Q 5 and the current mirror cause this fixed current I 0 to flow. Consequently, all of the transistors Q 24 , Q 23 , and Q 22 cause the current I 0 to flow.
[0020] The collector of the transistor Q 21 is connected with the collector of an NPN transistor Q 26 , and this transistor Q 26 has the collector and base short-circuited, and has the emitter connected to ground. The base of the transistor Q 26 is connected with an NPN transistor Q 27 , whose emitter is connected to ground, and the collector of this transistor Q 27 is connected to the collector of a PNP transistor Q 28 . The transistor Q 28 has the emitter connected to a power source VCC 1 , and has the base and collector short-circuited. Consequently, the transistor Q 28 causes the same current as that of the transistor Q 27 to flow. The base of the transistor Q 28 is connected with a PNP transistor Q 29 , whose emitter is connected to the power source VCC 1 , and the transistors Q 28 and Q 29 constitute the current mirror. The collector of the transistor Q 29 is connected with the collector of an NPN transistor Q 30 , and the emitter of this transistor Q 30 is connected to ground.
[0021] Consequently, the current (I 2 ) flowing through the transistor Q 21 flows into transistor Q 29 . The difference between the current flowing through the transistor Q 29 and the current flowing through the transistor Q 30 is obtained at a node B 1 which is a connection point of the collector of the transistor Q 29 and the collector of the transistor Q 30 , and this is outputted.
[0022] Here, the base of the transistor Q 10 is connected to the base of the transistor Q 26 . Consequently, these transistors Q 26 and Q 10 constitute the current mirror, and the transistor Q 10 causes the same current as that of the transistor Q 26 to flow. Since the transistor Q 26 causes the current I 2 flowing through the transistor Q 21 to flow, the current flowing through the node A 1 becomes the current I 1 -I 2 . Further, the base of the transistor Q 30 is connected to the base of the transistor Q 6 . Consequently, these transistors Q 6 and Q 30 constitute the current mirror, and the transistor Q 30 causes the same current as that of the transistor Q 6 to flow. Since the transistor Q 6 causes the current I 1 flowing through the transistor Q 1 to flow as it is, the current flowing through the node B 1 becomes the current I 2 -I 1 .
[0023] The connection point of the emitter of the transistor Q 21 and the collector of the transistor Q 22 is connected with one end of a resistor R 11 , and the other end of this resistor R 11 is connected to the collector of an NPN transistor Q 11 . This transistor Q 11 has the emitter connected to ground and the base connected to the base of the transistor Q 5 , and causes the current I 0 to flow.
[0024] The collector of the transistor Q 11 is connected with the emitter of an NPN transistor Q 12 and the other end of the resistor R 11 , and the base of this transistor Q 12 is connected with an output of a buffer amplifier BA 0 , and here, the input signal Vin is inputted. The collector of the transistor Q 12 is connected with the collector of a PNP transistor Q 13 . The emitter of the transistor Q 13 is connected to the power source VCC 2 , and the base and collector are short-circuited. The base of the transistor Q 13 is connected with the base of a PNP transistor Q 14 , whose emitter is connected to the power source VCC 2 , and the transistors Q 13 and Q 14 constitute the current mirror. The collector of the transistor Q 14 is connected to the collector of an NPN transistor Q 15 . The transistor Q 15 has the emitter connected to ground, and has the base and collector short-circuited, and causes the same current as that of the transistor Q 14 to flow. The base of the transistor Q 15 is connected with the base of an NPN transistor Q 16 , whose emitter is connected to ground. The transistors Q 15 and Q 16 constitute the current mirror.
[0025] The collector of the transistor Q 16 is connected with the collector of a PNP transistor Q 17 , and here it becomes a node A 2 . The transistor Q 17 has the emitter connected with the power source VCC 1 and the base connected with a PNP transistor Q 18 . The transistor Q 18 has the emitter connected with the power source VCC 1 and has the base and collector short-circuited. Consequently, the transistors Q 18 and Q 17 constitute the current mirror, and the transistor Q 17 causes the same current as that of the transistor Q 18 to flow. The collector of the transistor Q 18 is connected with the collector of an NPN transistor Q 19 , whose emitter is connected to ground.
[0026] The connection point of the emitter of the transistor Q 1 and the collector of the transistor Q 2 is connected with one end of a resistor R 12 , and the other end of this resistor R 12 is connected to the collector of an NPN transistor Q 31 . This transistor Q 31 has the emitter connected to ground and the base connected to the base of the transistor Q 5 , and causes the current I 0 to flow.
[0027] The collector of the transistor Q 31 is connected with the emitter of an NPN transistor Q 32 and the other end of the resistor R 12 , and the base of this transistor Q 32 is connected with the power source (½) VCC 2 . The collector of the transistor Q 32 is connected with the collector of a PNP transistor Q 33 . The emitter of the transistor Q 33 is connected to the power source VCC 2 , and has the base and collector short-circuited. The base of the transistor Q 33 is connected with the base of a PNP transistor Q 34 , whose emitter is connected to the power source VCC 2 , and the transistors Q 33 and Q 34 constitute the current mirror. The collector of the transistor Q 34 is connected with the collector of the NPN transistor Q 35 . The transistor Q 35 has the emitter connected to the ground, and has the base and collector short-circuited, and causes the same current as that of the transistor Q 34 to flow. The base of the transistor Q 35 is connected with the base of an NPN transistor Q 36 , whose emitter is connected to ground. The transistors Q 35 and Q 36 constitute the current mirror.
[0028] The collector of the transistor Q 36 is connected with the collector of a PNP transistor Q 37 , and here it becomes a node B 2 . The transistor Q 37 has the emitter connected with the power source VCC 1 and the base connected with a PNP transistor Q 38 . The transistor Q 38 has the emitter connected with the power source VCC 1 and has the base and collector short-circuited. Consequently, the transistors Q 38 and Q 37 constitute the current mirror, and the transistor Q 37 causes the same current as that of the transistor Q 38 to flow. The collector of the transistor Q 38 is connected with the collector of an NPN transistor Q 39 , whose emitter is connected to ground.
[0029] Here, the base of the transistor Q 39 is connected with the base of the transistor Q 15 , and the transistors Q 15 and Q 39 constitute the current mirror. Further, the base of the transistor Q 19 is connected with the base of the transistor Q 35 , and the transistors Q 35 and Q 19 constitute the current mirror.
[0030] The transistor Q 15 causes a current identical to that in the transistor Q 12 to flow, and on the other hand, the transistor Q 35 causes the same current as that of the transistor Q 32 to flow. Here, the emitter of the transistor Q 12 is connected with the other end of the resistor R 11 . A current that is derived by adding up the current flowing through the transistor Q 12 and the current flowing from the resistor R 11 flows into the transistor Q 11 , and this current flowing into the transistor Q 11 is the same as the current I 0 flowing through the transistor Q 5 . One end of the resistor R 11 is connected to the collector of the transistor Q 22 , and this transistor Q 22 causes the current I 0 to flow, similarly to the transistors Q 24 and Q 23 . Since the current I 2 flows through the transistor Q 21 , the current (I 0 -I 2 ) flows through the resistor R 11 . Consequently, the current I 2 , which derived by subtracting the current I 0 -I 2 flowing in the resistor R 11 from the current I 0 flowing through the transistor Q 11 , is assumed to flow through the transistor Q 12 . If the current I 2 flows through this transistor Q 12 , the current I 2 also flows through the transistor Q 15 , and the current I 2 also flows through the transistor Q 39 . Consequently, the current I 2 flows through the transistor Q 37 .
[0031] The transistor Q 35 causes current identical to that of the transistor Q 32 to flow. On the other hand, the transistor Q 35 causes the same current as that in the transistor Q 32 to flow. Here, the emitter of the transistor Q 32 is connected with the other end of the resistor R 12 . A current derived by adding up the current flowing into the transistor Q 32 and the current flowing from the resistor R 12 flows into the transistor Q 31 , and the current flowing into the transistor Q 31 is the same as the current I 0 flowing through the transistor Q 5 . One end of the resistor R 12 is connected to the collector of the transistor Q 2 , and this transistor Q 2 causes the current I 0 to flow, similarly to the transistors Q 24 and Q 23 . Since the current I 1 flows into the transistor Q 1 , the current (I 0 -I 1 ) flows into the resistor R 12 . Consequently, the current I 1 , which is derived by subtracting the current I 0 -I 1 flowing in the resistor R 12 from the current I 0 flowing through the transistor Q 31 , is assumed to flow through the transistor Q 32 . If the current I 1 flows through this transistor Q 32 , the current I 1 also flows through the transistor Q 35 , and the current I 1 also flows through the transistor Q 19 . Consequently, the current I 1 flows through the transistor Q 17 . The resistance values of the resistors R 11 and R 12 are usually set as R 11 =R 12 =R.
[0032] In this manner, the transistors Q 1 and Q 32 cause the current I 1 to flow, and the transistors Q 21 and Q 12 cause the current I 2 to flow. The input signal Vin is fed to the bases of the PNP transistor Q 1 and the NPN transistor Q 12 , and (½) VCC 2 is fed to the bases of the PNP transistor Q 21 and the NPN transistor Q 32 . Consequently, the voltage applied to both ends of the resistor R 11 is {(½) VCC 2 +1VBE}−(Vin−1VBE)={(½) VCC 2 −Vin}+2VBE, and the voltage applied to both ends of the resistor R 12 is {Vin+1VBE}−((½) VCC 2 −1VBE)={Vin−(½)VCC 2 }2VBE. With these voltages, the currents (I 0 -I 2 ) and (I 0 -I 1 ) flowing through the resistors R 11 and R 12 are decided, and eventually, the current I 1 flows through the transistors Q 1 , Q 9 , Q 17 , Q 30 , and Q 36 , the current (½)VCC 2 flows through the transistors Q 21 , Q 29 , Q 37 , Q 10 , and Q 16 , the current (I 1 -I 2 ) flows through the nodes A 1 and A 2 , and the current (I 2 -I 1 ) flows through the nodes B 1 and B 2 . That is, the transistors Q 1 and Q 21 operate as a differential transistor, and the voltage inputted to the transistor Q 21 is the fixed voltage (½) VCC 2 , the nodes A 1 and A 2 obtain the input signal Vin and the signal of an reverse polarity (reversed-phase signal), and the nodes B 1 and B 2 obtain a signal (in-phase signal) of the same polarity as the input signal.
[0033] Further, the node A 1 and the node A 2 are connected, and after the signals thereof are added, they are inputted to the positive input end of an operational amplifier OP 1 . This positive input end of the operational amplifier OP 1 is connected to the power source (½) VCC 1 via a resistor RL 1 and a buffer amplifier BA 01 . Further, the negative input end of the operational amplifier OP 1 is connected with the power source (½) VCC 1 via a resistor Rs 1 , and the output end of the operational amplifier OP 1 is connected via a resistor Rf 1 . Further, the operational amplifier OP 1 is provided with the power source VCC 1 as an operational power source. Consequently, the reversed-phase signal is amplified by this operational amplifier OP 1 , and outputted with VCC 1 as the power source.
[0034] Further, the node B 1 and the node B 2 are connected, and after the signals thereof are added, they are inputted to the positive input end of an operational amplifier OP 2 . This positive input end of the operation amplifier OP 2 is connected to the power source (½) VCC 1 via a resistor RL 2 . Further, the negative input end of the operational amplifier OP 2 is connected with the power source (½) VCC 1 via the buffer amplifier BA 01 and a resistor Rs 2 , and the output end of the operational amplifier OP 1 is connected via a resistor Rf 2 . Further, the operational amplifier OP 2 is fed with the power source VCC 1 as an operational power source. Consequently, the in-phase signal is amplified by this operational amplifier OP 2 , and outputted with VCC 1 as a power source.
[0035] Here, assuming that the resistance value of each resistor is RL 1 =RL 2 =RL, Rs 1 =Rs 2 =Rs, Rf 1 =Rf 2 =Rf, the gain of the level shift from VCC 2 to VCC 1 becomes (4×RL)÷R, and the gain as a BTL amplifier outputted from the operational amplifiers OP 1 and OP 2 becomes 2×(1+Rf/Rs).
[0036] That is, the level shift from the input signal Vin with (½) VCC 2 as a center to the output signal with (½) VCC 1 as a center becomes a ratio of R which is the resistance value of the resistors R 11 and R 12 disposed between an input route of the input signal Vin and an input route of the reference signal, and a load resistance RL 1 =RL 2 =RL disposed with (½) VCC 1 in the output side, and since this ratio exists at four places in total, they are added to become (4×RL)÷R. On the other hand, gain of each of the operational amplifiers OP 1 and OP 2 becomes 1+Rf/Rs with the resistance value of the input resistor as Rs and the resistance value of feedback resistor as Rf, and becomes 2×(1+Rf/Rs) by adding the gains of the in-phase side and the reversed phase side.
[0037] In this manner, in the present embodiment, the power source of a differential amplifier inputted with the input signal Vin is taken as VCC 2 , and the output thereof is converted into a power source VCC 1 reference by the current mirror. Consequently, there is no problem regardless of whether the power source VCC 1 or the power source VCC 2 is high voltage. In general, as the circuit for generating a control signal, a reference power source (generated by a fixed voltage circuit and the like from a battery power source) VCC 2 of a relatively low voltage and having small variation is used, whereas the output of the amplifier is a voltage for driving a coil, and uses the battery power source VCC 1 as it is preferable to use high voltage. However, when the battery power source fluctuates or the battery is consumed, the voltage is sometimes lowered considerably. In that case, it is also conceivable that the power source VCC 1 will become lower than the power source VCC 2 . In the present embodiment, even in such a case also, no problem occurs in the operation itself.
[0038] Further, since the present embodiment is of the type in which two outputs are generated in one phase and are added, the output signal becomes double.
[0039] In the above description, while it is described that all the current mirrors have the same emitter area, and cause the same current to flow, the emitter area may be appropriately changed and a mirror ratio may be changed. Further, while the input signal to the transistor Q 21 is taken as a fixed voltage, it may be taken as a reversed signal of the input signal Vin.
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An amplifier including the transistors of a first set operates by a power source VCC 2, and amplifies the input signal, changing in the voltage range of the power source VCC 2, in the voltage range of the power source VCC 2. The output of this amplifier operates using a power source VCC 1 with a converting portion including the transistors of a second set, and the output of the amplifier is converted into an output within the voltage range of the power source VCC 1. The two output amplifiers amplify the output of this converting portion based on a (½) VCC 1 reference. The converting portion performs the conversion using a plurality of transistors with the power source VCC 2 taken as a power source and a plurality of transistors 7 with the power source VCC 1 taken as a power source, as current mirrors.
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BACKGROUND OF THE INVENTION
The present invention relates to a bracket, and more particularly the present invention relates to a bracket intended to be used at a node point between horizontal and vertical frame members.
In particular the invention relates to a bracket suitable for use in forming a framework, which framework can constitute a structural portion of a building, such as a house, hospital, school or the like.
At the present time there is a need for a building system that will enable houses, hospitals, schools and other buildings to be built rapidly, the resultant buildings having a high degree of thermal insulation to minimise running costs.
It has been proposed to provide structures, such as houses, schools and the like by erecting a steel framework to form the "skeleton" of the building. Difficulties are encountered in connecting the members of such a framework together, so that the frame has a controlled tension, and in connecting the members of the framework to a sub-structure such as a concrete raft or a lower portion of the framework.
OBJECT OF THE INVENTION
The present invention seeks to provide an improved bracket which will facilitate the connecting of frame members of this type, and in utilising a bracket in accordance with the present invention it has been found possible to use structural members formed from a cold rolled box section, filled with a foamed plastics material to minimise any risk of corrosion and also to provide the members with a high degree of thermal-insulation.
BRIEF SUMMARY OF THE INVENTION
According to the broadest aspect of this invention there is provided a bracket for use at a node point in a framework between two horizontal members and a vertical member, said bracket comprising a first channel member having a base and two upstanding side walls, the longitudinal axis of which is aligned with the axis of said two horizontal members, said channel member being dimensioned to accommodate the base of the substantially vertical member, and also to accommodate the ends of the horizontal members, between the vertical member and the ends of the channel, means being provided for mounting said channel member on a sub-structure.
Preferably the side walls of said channel are provided with a plurality of apertures to enable fastening means, such as blind-rivets, to be engaged with at least the horizontal members located within the channel.
In preferred embodiments of the invention the means for fastening the bracket to a sub-structure comprise an element secured, such as by welding, to the underneath of the base of the said channel member, and, in one embodiment said element comprises a "L" sectioned strip, a first arm of the strip being aligned with one side wall of the channel but extending away therefrom, a second arm of the strip abutting the base of the channel and protruding laterally beyond the other side wall of the channel.
One arm of the strip (e.g. the first arm) may be provided with apertures and the other arm of the strip (e.g. the second arm) may be provided with notches in the free edge thereof to enable the bracket to be mounted on mutually perpendicular studs protruding from a concrete raft or the like.
Preferably the arms of the channel member are inclined inwardly.
This invention also relates to a framework comprising at least one bracket as described above and a plurality of frame members connected thereto.
Preferably each said frame member comprises a cold rolled box section, which may be rolled from steel treated to minimise corrosion, such as pre-galvanised steel. Conveniently each cold rolled box section is provided with a lock seam and is thus formed from a single sheet, and advantageously each said cold rolled box section is filled with a substantially rigid foamed plastics material, such as a polyurethane foam a polyisocyanurate foam or a phenolic resin based foam. The frame members may be provided with apertures to receive fastening means, such as blind-rivets.
Conveniently each frame member is of substantially square or rectangular section, two opposed faces having the central regions there of being recessed.
A membrane may be secured to one face of the completed framework, said membrane being formed from a cross laminate of orientated high density polyethylene.
A foamed plastics material such as polyurethane foam, or a phenolic resin based foam, may be applied to areas of said membrane to fill voids defined by the membrane and adjacent members of the framework.
Preferably the framework is secured to a concrete raft or the like by means of engagement between said bracket and a support plate embedded in the raft. The support plate may be associated with foundation bolts, which are embedded in the raft.
Conveniently said support plate is embedded in the raft by initially forming the base of a raft, and subsequently supporting the support plate and the associated foundation bolts in a desired position relative to the base of the raft and filling the interspace between the base of the raft and the support plate with concrete, and permitting that concrete to cure.
Advantageously members are connected to said support plate to act as formwork to define the volume of concrete poured, at least some of said members being removable after the concrete has cured.
The framework may support a roof and may thus constitute a building. The external face of the framework may be clad, for example by means of a conventional wall built spaced therefrom, or with plaster or other rendering.
It will be appreciated that by utilising brackets in accordance with the present invention a framework can rapidly be constructed from elongate elements formed as cold rolled box sections of mild steel, for example, appropriately treated to minimise corrosion, the cold rolled box section members being filled with a rigid foam material. It has been found that if an appropriate cross section is utilised, such members can be very strong, even though the steel utilised is very thin. Thus the members will be light, relatively inexpensive, and because they are filled with foam, will exhibit excellent thermal insulation properties. By utilising brackets in accordance with the present invention such members can rapidly and securely be connected to the brackets, for example by means of "blind-rivets" providing a strong and stable structure. If the framework constituting this strong and stable structure is then provided with the membrane of polythene, or a corresponding membrane, and a foam plastics material is applied to the membrane, the resulting structure has substantial stength, excellent thermal insulation properties, and can be very rapidly assembled. Such a structure forms an ideal "skeleton" for a building and enables buildings to be built rapidly and cheaply, but yet have excellent thermal insulation properties.
It is envisaged that it will be quite feasible for a framework as outlined above to be utilised as the "skeleton" of a two or three storey building, but it is to be understood that if buildings of greater height are to be built, a similar framework may be utilised reinforced, where necessary, by a primary skeleton formed from RSJ's.
It is envisaged that, in utilising a building system as described hereinafter in greater detail, the principal components will be manufactured under factory conditions, the elongate structural members to form the framework all being manufactured to have standard lengths, and the appropriate brackets being manufactured to have appropriate dimensions. All the appropriate components for a particular building can then rapidly be transferred to the selected site, and once the initial concrete raft has been laid, the principal "skeleton" of the building can be rapidly erected, usually within a matter of hours, or days at the most. Then the membrane can be applied to the exterior of the "skeleton" of the building, and a roof can be mounted on the "skeleton" thus enclosing the interior of the building from the weather, and facilitating the subsequent construction of the building.
INTRODUCTION OF THE DRAWINGS
In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described by way of example with reference to the accompanying drawings in which:
FIG. 1 is an exploded perspective view of part of framework that forms a building structure, showing a connector in accordance with the invention.
FIG. 2 is a perspective view of a larger part of the assembled framework as illustrated in FIG. 1;
FIG. 3 is a horizontal sectional view through part of the framework of FIG. 2, taken on the line III--III of FIG. 2.
FIG. 4 is a sectional figure showing how the support plate 2 is connected to the raft.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to FIG. 1, when a building is to be constructed, initially a concrete raft 1 is prepared. The raft may be a rectangular raft extending over the entire floor plan of the building to be constructed, or may merely extend around the periphery of the building. Of course the raft may be of any other shape, such as "L" or "H" shaped. Embedded into the raft, at appropriate locations, are a plurality of support plates 2, (by a method that will be described hereinafter) each such support plate having a horizontal portion 3 on the upper surface of the raft, flush with that upper surface and a vertical portion on a vertical side wall of the raft, and flush with that side surface. Foundation bolts 5, 6 are embedded in the raft, and the threaded ends of these foundation bolts protrude vertically and horizontally from these support plates 2.
A framework is then assembled on the raft, the framework being connected to the raft by being secured to the support plates 2. The framework is created from elongate elements 7 which are all of the same cross-section and may preferably all be of standard lengths. Thus it will be appreciated that when a building is to be constructed the elongate elements 7 can be prefabricated in a factory, and cut to various standard lengths the appropriate number elements then being transported to the building site. The elements can be rapidly assembled to form the framework since each element is interchangeable with any other element.
Each element 7 is a hollow cold rolled lock seamed tube formed from hot dipped galvanised mild steel. The tube is of substantially square cross-section, but two elongate recesses 8, 9 are formed in two opposed faces of the tube so that the tube is of generally "H" cross-section and the lock seam 10 is located in the base of one of these recesses 8. The tube may be entirely filled with a substantially rigid foamed plastics material. This may be a polyurethane foam or any other appropriate foam, and examples of appropriate foams will be specified hereinafter. A tube of this construction may be fabricated from relatively thin galvanised mild steel but will have substantial strength and will also have excellent thermal insulation properties by virtue of the foam filling for the tube.
It is to be appreciated that whilst the tube has been specified as being manufactured from hot dipped galvanised mild steel, the galvanising merely provides the mild steel with corrosion resistant properties, and the tube may be treated in any appropriate way to provide corrosion resistance or may be fabricated from any appropriate corrosion resistant material.
As shown in FIG. 1 two lower horizontal elongate elements 11, 11' and one vertical element 12 must be interconnected at a single node point immediately adjacent the support plate 2. The bracket 13 facilitates the construction of such a node point.
The bracket 13 comprises a first member 14 consisting of a strip of "L" section. One arm of the "L", 15 is adapted to be vertical and is adapted to be located in position in abutment against the vertical face 4 of the support plate 2. This vertical arm 15 is provided with two apertures 16 which are adapted to be located over the foundation bolts 6 that protrude horizontally from the vertical face 4 of the support plate 2. The second arm 17 of the "L" sectioned member 14 is adapted to lie horizontally on top of the support plate 2, and the rear edge of this arm 17 is notched 18 so that, as the bracket 13 is moved so the horizontal threaded ends of the foundation bolts 6 pass through the apertures 16, the vertically extending threaded ends of the foundation bolts 5 on the support plate 2 pass through the notches 18. Appropriate washers and nuts can then be located on the threaded ends of the foundation bolts and tightened thus securely mounting the bracket 13 in position.
Welded or otherwise secured to the top of the arm 17 of the first member 14 is a channel member 19. The channel member 19 has a flat base 20 secured to the top of the arm 17, for example by appropriate welds 21, 22. One outstanding side wall 23 of the channel 19 is flush with the front of the arm 15 of the "L" sectioned member 14. A plurality of apertures 24 is provided in this wall 23 of the channel and also in the other upstanding wall 25 of the channel. The upstanding walls 23, 25 may convege slightly towards one another.
It can be seen that, when a node point is to be constructed, once the bracket 13 has been mounted in position on the support plate 2, the vertical elongate element 12 can be inserted into the central space 26 defined by the channel member 19. When the end of the elongate element 12 has been inserted in position, it can be secured in position by means of "blind-rivets" or the like which are mounted in position through the apertures 24 in the walls 23 and 25 of the channel member 19. Apertures 27 may be provided in the elongate elements to receive the "blind-rivets". The two horizontal elongate elements 11, 11' can then be located in the portions of the channel member 19 located on either side of the centrally located further section of channel 26, and again these horizontal members can be secured in position by appropriate means (such as "blind-rivets") introduced through the apertures 24 in the side walls 23, 25 of the channel 19.
Thus a node point between two horizontal frame members 11, 11' and a vertical frame member 12 can readily and rapidly be created, the resultant node point being neat and serviceable, the frame members all being securely connected to the underlying sub-structure, i.e. the raft 1. Further frame members, such as horizontal upper frame members 28, 29, may then be connected to the upper portion of the upright member 12 by means of "U" shaped brackets 30. Each bracket 30 has a base 31 dimensioned to be received in a recess formed on one face of the vertical frame member 12, and two horizontal arms 32, to be received in the recesses on the horizontal member 29. Appropriate apertures 33 are provided to receive "blind-rivets" to complete the connection.
A frame work such as the framework shown schematically in FIG. 2 can therefore be constructed, although it is to be appreciated that additional transverse re-inforcing frame members, such as the member 34 can be added to the framework, if so desired, the reinforcing members being connected to the members illustrated by means of "U" shaped connecting brackets 35 provided with appropriate apertures to receive appropriate fastening means such as "blind-rivets". One "U" shaped bracket 35 is shown connected, by means, for example, of "blind-rivets" passing through apertures in the base of the "U" shaped bracket, to the horizontal member 29 ready to receive a further reinforcing member 34', which can then be securely mounted in position with, for example, "blind-rivets" passing through apertures in the two side arms of the "U" shaped bracket 35.
The framework, as finally completed, will of course define appropriate apertures to receive windows, doors and the like.
When the framework has been completed, the framework may define merely the exterior wall of the building or structure, or may also define one or more interior walls. One surface of each wall is then provided with a sheet 36 of appropriate material, and the function of this sheet will become clear from the following description. Preferably the sheet is of translucent polythene and may be a cross laminate of oriented high density polythene as sold under Trade Mark "Valeron" by Van Leer (U.K.) Ltd. of Ellesmere Port, Liverpool. The sheet is secured in position to extend across all the apertures defined by the framework, and is preferably located on the exterior of the framework, so that the sheet then defines the outer-most surface of the structure. The sheet may be held in position by means of double-sided adhesive tape 37.
A roof can rapidly be assembled, in a conventional way, on top of the framework and then the structure is weather-proof.
A sprayed foam material, such as sprayed polyurethane foam or sprayed polyisocyanurate foam may then be sprayed, from the interior of the framework, onto the polythene sheet. An initial thin spray of foam is applied which as a result of the heat generated during the foaming process, bonds firmly to the polythene sheet and rapidly cures or solidifies. One or more subsequent layers of foam can be provided until the entire inter-space defined by the frame members and the polythene sheet is filled with foam material 38, apart from those regions of the framework that define apertures to accommodate doors or windows, and the inner surface of the foam is flush with the inner surfaces of the various frame members. Internal cladding, such as conventional dry lining, can be mounted in position on the interior of the walls and an appropriate external cladding can be provided. The external cladding may be of any desired form, but in FIG. 1 it can be seen that an outer brick wall 39 can be constructed on a protruding lip 40 of the raft 1 or on corresponding footings to provide a cavity wall, the building then having the external appearance of a conventional brick building.
A building constructed by the method described above can be constructed very rapidly, and thus very cheaply, but the resultant building will have excellent thermal insulation properties.
The insulating foam utilised may be any convenient foam, but reference may be made to a polyurethane foam, the components of which are sold under the Trade Mark "Isofoam" by The Baxendon Chemical Company Limited of Accrington, Lancashire. The foam is created by mixing an isocyanate and a polyol. Grade SS212 may be found suitable for spraying, and grade RM114 may be found suitable for injection into the hollow box sections constituting the frame members. Such a foam may easily be treated to have fire resistance properties. However, phenolic resin based foams may be used which have very low class 0 fire resistance properties.
It is to be noted, from Fig. 3, that the lock seams 10 of the various members forming the frame work are so located that when the foam material 38 has been sprayed onto the polyethylene sheet 36 the foam material covers the lock seam 10, thus minimising any risk of corrosion commencing at this point.
Of course, all the metallic components of the framework may be treated, as mentioned above, to minimise any risk of corrosison, but such parts that are not covered by the foam material, such as the exterior portions of the bracket 13, may be coated with an appropriate material, such as bitumastic paint after the framework has been assembled.
Referring now to FIG. 4, the method of affixing the support plate 2 to the raft 1 will now be described. Initially when preparing the raft footings are dug in the ground, the footings extending around the outer periphery of the area where the raft is to be formed. Optionally footings can be provided within the area of the raft where load bearing walls are to be provided. The footings and the area between the footings are then filled with concrete to form a raft 40, there being a number of reinforcing rods 41 extending upwardly from the raft.
Subsequently the support plates 2 are shown in FIG. 4 is located in the position that the support plates are to adopt on the completed raft. The foundation bolts 5 and 6 are located in position.
To locate the support plate 2 that is shown in FIG. 4 in position an elongate channel section member 42 is located in position on the exposed stud of the foundation bolts 6 and is retained in position by means of a nut 43. A similar, but narrower gauge, channel section member 44 is similarly located in a position parallel with the channel 4 but spaced inwardly from the periphery of the raft. The channel member 44 is connected to the assembly of the support plate 2 and the bolts 5 and 6 by means of a tie rod 45. The channel section members 42 and 44 are both supported by cooperating wedge arrangements 46, 47 which can be adjusted to ensure that the vertical flanges of the channel members 42 and 44 are vertical and that the channel members adopt the desired position. The interspace between the vertical flanges of the channel members 42 and 44 can then be filled with concrete 48 to a level 49 which is flush with the top of the uppermost surface of the horizontal part 3 of the support plate 2. The concrete then cures. Thus the foundation bolts 5 and 6 become embedded in concrete. The channel member 42, having acted as a formwork, can then be removed. It will thus be appreciated that the concrete 48 extends entirely around the periphery of the raft 40.
FIG. 4 illustrates in phantom a support bracket 13 in accordance with the invention in position on the support plate 2 and also shows a clip 50 attached to one part of the support bracket 13 which is utilised to support a sheet of chip-board 51 which can form a floor of a building. The sheet of chipboard 51 rests, in cooperation with appropriate packing 52, on the upper horizontal flange of the channel section member 44.
The interspace 53 between the chipboard and the uppermost surface of the concrete 48 may be filled with foam, and foam may also be injected between the uppermost surface of the raft 40 and the chipboard constituting the floor both to add support to the floor and to add insulating properties to the complete structure.
It is to be emphasised that when a building is constructed by the method described above, once the raft has been constructed, the framework can be rapidly assembled, the roof can be mounted in position on the framework, and the polythene sheet can be mounted in position on the framework within a matter of days. The interior of the building is then fully protected from the weather and, when the spray has been applied to the polythene, which is again a step that can be performed rapidly, work can commence on the interior fitting of the building. Simultaneously work can commence on the construction of an outer wall 39, if such an outer wall is to be provided. It is to be understood that in certain circumstances it may be suitable to apply plaster on some other rendering directly to the exterior of the wall, constituted by the framework and the foam material 38. If this course of action is to be adopted appropirate laths, or the equivalent, are connected to the wall, and the plaster or rendering is held by the laths.
Thus a builing as described above can be constructed rapidly, and therefore economically, from components that are prefabricated in a factory to within close tolerances. Thus the components can be manufactured under ideal conditions. It is envisaged that a building constructed as described above will have very good thermal insulation properties and will thus only require a minimum quantity of energy to maintain an even temperature within the building.
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A bracket 13 for use at a node point in a framework between two horizontal members 11, 11' and vertical member 12, said bracket comprising a first channel member 19 having a base 20 and two upstanding side walls 23, 25, the longitudinal axis of which is aligned with the axis of said two horizontal members, said channel member 19 being provided with means defining two transverse partition walls 27, 28 defining a space within the first channel member intermediate the ends thereof for accommodating the base of the substantially vertical member 12, and defining spaces between the partition walls and the ends of the channel to accommodate the ends of the horizontal members, a further element 14 being provided for mounting said channel member 19 on a sub-structure 1.
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BACKGROUND
Technical Field
The present invention relates to a package substrate for chip/chips package, especially relates to a package substrate having molding compound wrapped four lateral sides and bottom side to stiffen the high density package substrate.
Description of Related Art
FIG. 1 Shows a Prior Art.
FIG. 1 shows a prior art package substrate for chip package. US20120146209A1 disclosed a chip package which has a through-holed interposer 21 , a redistribution-layer 213 disposed on a top side of the interposer 21 . A molding layer 22 is formed to embed the through-holed interposer 21 . The molding layer 22 has an exposed first surface 22 a and a second surface 22 b . A built-up structure 24 is formed on the second surface 22 b of the molding layer 22 . The built-up structure 24 comprises a dielectric layer 240 and a wiring layer 241 , such that the conductive vias 242 are formed in the dielectric layer 240 for electrically connecting the wiring layer 241 to the conductive through metal 210 . A solder mask layer 25 is formed on the outermost dielectric layer 240 to expose conductive pads 243 . The through-holed interposer 21 is made of glass or ceramic such as Al2O3 and AlN, wherein the ceramic has a CTE of about 3 ppm/° C. that is close to silicon. A chip 27 is flip-chip electrically connected to the electrode pads 211 of the redistribution-layer 213 through a plurality of solder bumps 271 , an underfill 270 is used to fill the space between the electrode pads 211 and the chip 27 , and a plurality of solder balls 26 are mounted on the conductive pads 243 for the package to electrically coupled to an outside print circuit board (not shown).
The prior art package substrate is mainly stiffened by the glass/ceramic interposer 21 . However, semiconductor package technology moves faster and faster, a thinner thickness package substrate without having a glass/ceramic interposer is developed, a different stiffening structure has to be conceived for a high density package substrate used for chip or chips package.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a prior art.
FIGS. 2A ˜ 2 B show a first embodiment according to the present invention.
FIGS. 3A ˜ 3 B show a second embodiment according to the present invention.
FIGS. 4A ˜ 4 B show a third embodiment according to the present invention.
FIGS. 5A ˜ 5 B show a fourth embodiment according to the present invention.
FIGS. 6A ˜ 6 B show a fifth embodiment according to the present invention.
FIGS. 7A ˜ 7 B show a sixth embodiment according to the present invention.
FIGS. 8A ˜ 8 B show a seven embodiment according to the present invention.
FIGS. 9A ˜ 9 B show an eighth embodiment according to the present invention.
FIGS. 10A ˜ 10 B show a top view of FIGS. 9A ˜ 9 B.
DETAILED DESCRIPTION OF THE INVENTION
A molding compound wrapped thin film high package substrate is disclosed. The package substrate has a top side for chip mount and a bottom side for mounting the chip package onto a system board. The molding compound wrapped the package substrate at least four lateral side and a bottom side to stiffen the thin film package substrate.
FIGS. 2A ˜ 2 B Show a First Embodiment According to the Present Invention.
FIG. 2A shows a first package substrate according to the present invention.
FIG. 2A shows a redistribution layer (RDL) which has a redistribution circuitry 31 embedded in a dielectric layer 31 D; the redistribution circuitry 31 has a plurality of top metal pads 31 T and a plurality of bottom metal pads 31 B; the redistribution circuitry 31 fans out downwards so that a density of the bottom metal pads 31 B is lower than a density of the top metal pads 31 T. A plurality of top openings 321 are formed on a top side of the dielectric layer 31 D; each top opening 321 exposes a top surface of a corresponding top metal pad 31 T. A molding compound 35 wraps four lateral sides and bottom side of the dielectric layer 31 D; and a plurality of bottom openings 351 are formed on a bottom side of the molding compound 35 ; each opening 351 exposes a bottom side of a corresponding bottom metal pad 31 B.
FIG. 2B shows a chip package using the package substrate of FIG. 2A .
FIG. 2B shows at least one chip 36 is exemplarily configured on a top side of the redistribution circuitry 31 and electrically coupled to the top metal pads 31 T of the redistribution circuitry 31 . A plurality of solder balls 37 are configured on a bottom side of the redistribution circuitry 31 , each solder ball 37 is configured on a bottom side of a corresponding bottom metal pad 31 B.
FIGS. 3A ˜ 3 B Show a Second Embodiment According to the Present Invention.
FIG. 3A shows a modified structure of FIG. 2A .
FIG. 3A is similar to FIG. 2A . However, FIG. 3A has a plurality of metal pillars 33 formed on a bottom side of the redistribution circuitry 31 . FIG. 3A shows a redistribution layer (RDL) which has a redistribution circuitry 31 embedded in a dielectric layer 31 D; wherein the redistribution circuitry 31 has a plurality of top metal pads 31 T and a plurality of bottom metal pads 31 B; the redistribution circuitry 31 fans out downwards so that a density of the bottom metal pads 31 B is lower than a density of the top metal pads 31 T. A plurality of metal pillars 33 are formed on a bottom side of the redistribution circuitry 31 , each metal pillar 33 is configured on a bottom side of a corresponding bottom metal pad 31 B. A plurality of top openings 321 are formed on a top side of the dielectric layer 31 D; each top opening 321 exposes a top surface of a corresponding top metal pad 31 T. A molding compound 35 wraps four lateral sides and bottom side of the dielectric layer 31 D; and a plurality of bottom openings 351 are formed on a bottom side of the molding compound 35 ; each opening 351 exposes a bottom side of a corresponding bottom metal pad 31 B.
FIG. 3B shows a chip package using the package substrate of FIG. 3A .
FIG. 3B shows at least one chip 36 is exemplarily configured on a top side of the redistribution circuitry 31 and electrically coupled to the top metal pads 31 T of the redistribution circuitry 31 . A plurality of solder balls 37 are configured on a bottom side of the redistribution circuitry 31 , each solder ball 37 is configured on a bottom side of a corresponding metal pillar 33 .
FIGS. 4A ˜ 4 B Show a Third Embodiment According to the Present Invention.
FIG. 4A shows a modified structure of FIG. 3A . FIG. 4A shows a package substrate which has a redistribution layer RDL. The RDL comprises a left redistribution circuitry 41 and a right redistribution circuitry 411 , both redistribution circuitry 41 , 411 are embedded in a dielectric layer 41 D. The left redistribution circuitry 41 has a plurality of top metal pads 41 T and a plurality bottom metal pads 41 B; the left redistribution circuitry 41 fans out downwards so that a density of the bottom metal pads 41 B is lower that a density of the top metal pads 41 T. The right redistribution circuitry 411 is similar to the first redistribution circuitry 41 . The right redistribution circuitry 411 has a plurality of top metal pads and a plurality of bottom metal pads; the right redistribution circuitry 411 fans out downwards so that a density of the bottom metal pads is lower that a density of the top metal pads. A plurality of top openings 421 are formed on a top side of the dielectric layer 41 D; each top opening 421 exposes a top surface of a corresponding top metal pad 41 T. A plurality of metal pillars 43 are formed on a bottom side of the redistribution circuitry 41 , each metal pillar 43 is configured on a bottom side of a corresponding bottom metal pad 41 B. A molding compound 45 wraps four lateral sides and bottom side of the dielectric layer 41 D; the molding compound 45 also wraps the plurality of metal pillars 43 ; and a plurality of bottom openings 451 are formed on a bottom side of the molding compound 45 ; each opening 451 exposes a bottom side of a corresponding metal pillar 43 . A lateral communication circuitry 412 is configured between the left redistribution circuitry 41 and the right redistribution circuitry 411 ; the lateral communication circuitry 412 has a plurality of left top metal pads 412 T and a plurality of right top metal pads 413 T exposed on a top side of the dielectric layer 41 D.
FIG. 4B shows a chip package using the package substrate of FIG. 4A .
FIG. 4B shows at least one left chip 461 is exemplarily configured on a top side the left redistribution circuitry 41 and electrically coupled to the top metal pads 41 T of the left redistribution circuitry 41 ; and at least one right chip 462 is exemplarily configured on a top side of the right redistribution circuitry 411 and electrically coupled to the top metal pad 41 T of the right redistribution circuitry 411 . A plurality of solder balls 47 are configured on a bottom side of the redistribution circuitry 41 , 411 , each solder ball 47 is configured on a bottom side of a corresponding metal pillar 43 . The lateral communication circuitry 412 communicates the first chip 461 and the second chip 462 .
FIGS. 5A ˜ 5 B Show a Fourth Embodiment According to the Present Invention.
FIG. 5A shows a modified structure of FIG. 4A .
FIG. 5A shows a cavity 48 is formed on a bottom side of the dielectric layer 41 D, and enclosed by the molding compound 45 ; and a plurality of openings 452 are formed on a bottom side of the dielectric layer 41 D within the cavity 48 , each opening 452 exposes a bottom side of a corresponding bottom metal pad 41 B within the cavity 48 .
FIG. 5B shows a chip package using the package substrate of FIG. 5A .
FIG. 5B shows two chips 481 , 482 are exemplarily shown to be electrically coupled to the bottom metal pads 41 B within the cavity 48 . A plurality of solder balls 47 are configured on a bottom side of the redistribution circuitry 41 , 411 , each solder ball 47 is configured on a bottom side of a corresponding metal pillar 43 .
FIGS. 6A ˜ 6 B Show a Fifth Embodiment According to the Present Invention.
FIG. 6A shows a package substrate according to the presentation invention.
FIG. 6A shows a package substrate which has a first redistribution layer RDL 1 . The RDL 1 is built according to a first design rule. The RDL 1 has a first redistribution circuitry 51 embedded in a first dielectric layer 51 D; the first redistribution circuitry 51 has a plurality of first top metal pads 51 T and a plurality of first bottom metal pads 51 B. The package substrate has a second redistribution layer RDL 2 which is configured on a bottom side of the first redistribution layer RDL 1 .
The RDL 2 is built according to a second design rule and has a second redistribution circuitry 52 embedded in a second dielectric layer 52 D; the second redistribution circuitry 52 has a plurality of second top metal pads 52 T and a plurality of second bottom metal pads 52 B; each second top metal pad 52 T is electrically coupled to a corresponding first bottom metal pad 51 B; the first redistribution circuitry 51 fans out downwards so that a density of the first bottom metal pads 51 B is lower than a density of the first top metal pads 51 T; the second redistribution circuitry 52 fans out downwards so that a density of the second bottom metal pads 52 B is lower than a density of the second top metal pads 52 T. The second design rule has a lower circuitry density than the first design rule has. A plurality of top openings 521 are configured on a top side of the first dielectric layer 51 D; each top opening 521 exposes a top surface of a corresponding first top metal pad 51 T; a molding compound 55 wraps four lateral sides and a bottom side of, at least, the second dielectric layer 52 D; and a plurality of bottom openings 551 are formed on a bottom side of the molding compound 55 ; each opening 551 exposes a bottom side of a corresponding second bottom metal pad 52 B.
FIG. 6B shows a chip package using the package substrate of FIG. 6A .
FIG. 6B shows at least one chip 56 is exemplarily shown to be electrically coupled to the first top metal pads 51 T. A plurality of solder balls 57 are configured on a bottom side of the second redistribution circuitry 52 , each solder ball 57 is configured on a bottom side of a corresponding second metal pad 52 B.
FIGS. 7A ˜ 7 B Show a Sixth Embodiment According to the Present Invention.
FIG. 7A shows a package substrate according to the present invention. FIG. 7A shows a package substrate which has a first redistribution layer RDL 1 . The RDL 1 is built according to a first design rule; the RDL 1 has a first redistribution circuitry 51 embedded in a first dielectric layer 5 D; the first redistribution circuitry 51 has a plurality of first top metal pads 51 T and a plurality of first bottom metal pads 51 B. The package substrate also has a second redistribution layer RDL 2 which is configured on a bottom side of the first redistribution layer RDL 1 ; the RDL 2 is built according to a second design rule; the RDL 2 has a second redistribution circuitry 52 embedded in a second dielectric layer 52 D; the second redistribution circuitry 52 has a plurality of second top metal pads 52 T and a plurality of second bottom metal pads 52 B; each second top metal pad 52 T is electrically coupled to a corresponding first bottom metal pad 51 B. The first redistribution circuitry 51 fans out downwards so that a density of the first bottom metal pads 51 B is lower than a density of the first top metal pads 51 T; the second redistribution circuitry 52 fans out downwards so that a density of the second bottom metal pads 52 B is lower than a density of the second top metal pads 52 T. The second design rule has a lower circuitry density than the first design rule has. A plurality of metal pillars 53 are formed on a bottom side of the second redistribution circuitry 52 , each metal pillar 53 is configured on a bottom side of a corresponding bottom metal pad 52 B; a plurality of top openings 521 are configured on a top side of the first dielectric layer 51 D; each top opening 521 exposes a top surface of a corresponding first top metal pad 51 T; a molding compound 55 wraps four lateral sides and a bottom side of, at least, the second dielectric layer 52 D; and a plurality of bottom openings 551 are formed on a bottom side of the molding compound 55 ; each opening 551 exposes a bottom side of a corresponding metal pillar 53 .
FIG. 7B shows a chip package using the package substrate of FIG. 7A .
FIG. 7B shows at least one chip 56 is exemplarily shown to be electrically coupled to the first top metal pads 51 T; a plurality of solder balls 57 are configured on a bottom side of the second redistribution circuitry 52 , each solder ball 57 is configured on a bottom side of a corresponding metal pillar 53 .
FIGS. 8A ˜ 8 B Show a Seven Embodiment According to the Present Invention.
FIG. 8A shows a package substrate according to the present invention. FIG. 8A shows a package substrate which has a first redistribution layer RDL 1 , the RDL 1 is built according to a first design rule; the RDL 1 has a first redistribution circuitry 61 , 611 embedded in a first dielectric layer 61 D; the first redistribution circuitry 61 , 611 has a plurality of first top metal pads 61 T and a plurality of first bottom metal pads 61 B.
The package substrate also has a second redistribution layer RDL 2 which is built according to a second design rule. The RDL 2 is configured on a bottom side of the first redistribution layer RDL 1 . The RDL 2 has a second redistribution circuitry 62 , 622 embedded in a second dielectric layer 62 D; the second redistribution circuitry 62 , 622 has a plurality of second top metal pads 62 T and a plurality of second bottom metal pads 62 B. The second design rule has a lower circuitry density than the first design rule has. The first redistribution circuitry 61 , 611 further comprises: a first left redistribution circuitry 61 , embedded in the first dielectric layer 61 D, having a plurality of first left top metal pads 61 T and a plurality of first left bottom metal pads 61 B; a first right redistribution circuitry 611 , embedded in the first dielectric layer 61 D, having a plurality of first right top metal pads and a plurality of first right bottom metal pads.
The second redistribution circuitry 62 , 622 further comprises: a second left redistribution circuitry 62 , embedded in a second dielectric layer 62 D, has a plurality of second left top metal pads 62 T and a plurality of second left bottom metal pads 62 B; a second right redistribution circuitry 622 , embedded in the second dielectric layer 62 D, having a plurality of second right top metal pads 62 T and a plurality of second right bottom metal pads 62 B; each second left top metal pad 62 T is electrically coupled to a corresponding first left bottom metal pad 61 B; each second right top metal pad 62 T is electrically coupled to a corresponding first right bottom metal pad 61 B. The first left redistribution circuitry 61 fans out downwards so that a density of the first left bottom metal pads 61 B is lower than a density of the first left top metal pads 61 T. The first right redistribution circuitry 611 fans out downwards so that a density of the first right bottom metal pads is lower than a density of the first right top metal pads; the second left redistribution circuitry 62 fans out downwards so that a density of the second left bottom metal pads 62 B is lower than a density of the second left top metal pads 62 T; the second right redistribution circuitry 622 fans out downwards so that a density of the second right bottom metal pads is lower than a density of the second right top metal pads. A plurality of top openings 621 configured on a top side of the first dielectric layer 61 D; each top opening 621 exposes a top surface of a corresponding first top metal pad 61 T; a plurality of metal pillars 63 are formed on a bottom side of the second redistribution circuitry 62 , each metal pillar 63 is configured on a bottom side of a corresponding second bottom metal pad 62 B; and a molding compound 65 wraps four lateral sides and bottom side of, at least, the second dielectric layer 62 D; the molding compound 65 also wraps the plurality of metal pillars 63 ; and a plurality of bottom openings 651 are formed on a bottom side of the molding compound 65 ; each opening 651 exposes a bottom side of a corresponding metal pillar 63 . A lateral communication circuitry 612 , built according to the first design rule, is configured between the first left redistribution circuitry 61 and the first right redistribution circuitry 611 ; the lateral communication circuitry 612 has a plurality of left top metal pads 612 T and a plurality of right top metal pads 613 T exposed on a top side of the first dielectric layer 61 D.
FIG. 8B shows a chip package using the package substrate of FIG. 8A .
FIG. 8B shows two chips 661 , 662 configured on a top of the first redistribution circuitry and on a top of the lateral communication circuitry 612 . The chip 661 is exemplarily shown to be electrically coupled to the left top metal pads 612 T of the lateral communication circuitry 612 ; and the right chip 662 is exemplarily shown to be electrically coupled to the right top metal pads 613 T of the lateral communication circuitry 612 ; the left chip 661 and the right chip 662 are able to communicate with each other through the lateral communication circuitry 612 . A plurality of solder balls 67 are configured on a bottom side of the second redistribution circuitry 62 , each solder ball 67 is configured on a bottom side of a corresponding metal pillar 63 .
FIGS. 9A ˜ 9 B Show an Eighth Embodiment According to the Present Invention.
FIG. 9A is a modified structure of FIG. 8A .
FIG. 9A shows a cavity 68 is formed on a bottom side of the second dielectric layer 62 D, and enclosed by the molding compound 65 ; and a plurality of openings 652 are formed on a bottom side of the second dielectric layer 62 D within the cavity 68 , each opening 652 exposes a bottom side of a corresponding second metal pads 62 B within the cavity 68 .
FIG. 9B shows a chip package using the package substrate of FIG. 9A .
FIG. 9B shows chips 681 , 682 are exemplarily shown to be electrically coupled to the second bottom metal pads 62 B within the cavity 68 . A plurality of solder balls 67 are configured on a bottom side of the second redistribution circuitry 62 , each solder ball 67 is configured on a bottom side of a corresponding metal pillar 63 .
FIGS. 10A ˜ 10 B Show a Top View of FIGS. 9A ˜ 9 B.
FIG. 10A shows a top view of FIG. 9A . FIG. 10A shows the molding compound 65 wraps four sides of the first dielectric layer 61 D and the lateral communication circuitry 612 is embedded in the first dielectric layer 61 D.
FIG. 10B shows a top view of FIG. 9B . FIG. 10B shows the chips 664 , 662 configured on the top surface of the first dielectric layer 61 D. The embedded lateral communication circuitry 612 communicates between the chip 661 and chip 662 .
While several embodiments have been described by way of example, it will be apparent to those skilled in the art that various modifications may be configured without departs from the spirit of the present invention. Such modifications are all within the scope of the present invention, as defined by the appended claims.
NUMERICAL SYSTEM
31 redistribution circuitry
31B bottom metal pad
31D dielectric layer
31T top metal pad
321 opening
33 metal pillar
35 molding compound
351 opening
36 chip
37 solder ball
38 cavity
381, 382 chip
41 left redistribution circuitry
411 right redistribution circuitry
412 lateral communication circuitry
412T, 413T top metal pad
41B bottom metal pad
41D dielectric layer
41T top metal pad
421 opening
43 metal pillar
45 molding compound
451 opening
452 opening
461, 462 chip
47 solder ball
48 cavity
481, 482 chip
51 redistribution circuitry
51B bottom metal pad
51D dielectric layer
51T top metal pad
52 redistribution circuitry
521 opening
52B bottom metal pad
52D dielectric layer
52T top metal pad
53 metal pillar
55 molding compound
551 opening
56 chip
57 solder ball
61 redistribution circuitry
611 redistribution circuity
612 lateral communication circuitry
612T top metal pad
613T top metal pad
61B bottom metal pad
61D dielectric layer
61T top metal pad
62 redistribution circuitry
621 opening
622 redistribution circuitry
62B bottom metal pad
62D dielectric layer
62T top metal pad
63 metal pillar
65 molding compound
651 opening
652 opening
66 chip
661, 662 chip
67 solder ball
68 cavity
681, 682 chip
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A package substrate for chip/chips package wrapped by a molding compound is disclosed. The molding compound functions as a stiffener for the thin film package substrate. One embodiment discloses at least one redistribution layer (RDL) is prepared and the RDL is wrapped by a molding compound. The molding compound wraps four lateral sides and bottom side of the RDL. A top side of the RDL is made for a chip to mount and a bottom side of the RDL is planted a plurality of solder balls so that the bottom side of the chip package is adaptive to mount onto a system board in a later process.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of and claims the benefit under 35 U.S.C. §120 from U.S. patent application Ser. No. 12/022,669, filed on Jan. 30, 2008, which claims priority under 35 U.S.C. §119 from Japanese Patent Application No. 2007-021366, filed on Jan. 31, 2007, the entire contents of each of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a light source device used for illumination of a display device or the like, and a surface light source device equipped with the light source device.
BACKGROUND
[0003] A general display device comprises a display panel, a circuit board, a light source device and the like. A light source device that irradiates light from the rear surface thereof is either a side light type (edge light type) including a light source on the side surface of an enclosure or a direct type including a light source on the bottom of an enclosure in a position opposed to a display panel.
[0004] Some of the side light type light source devices use a light guide plate in order to guide light from a light source to an opening of an enclosure. A light source device using a light guide plate propagates, inside the light guide plate, light emitted from a linear light source such as a cold-cathode tube or a point light source such as a light emitting diode (hereinafter referred to as an LED) and diffuses the light by way of a diffusion pattern provided in the light guide plate to take out the light in the shape of a plane at the opening of the enclosure.
[0005] With a light source device using a point light source such as an LED as a light-emitting element described above, the luminance of a display screen is enhanced by increasing the number of point light sources thus increasing an element density or increasing the current supplied to each point light source. In any way, heat from each point light source caused by light emission brings the periphery of the point light source at high temperature.
[0006] There is proposed a light source device including a light source substrate mounting heat-dissipating means, the light source substrate composed of a flexible printed circuit board (hereinafter referred to as an FPC) mounting point light sources and a wiring pattern to feed power to each light source (for example, Patent Reference 1 (Japanese Published Unexamined Patent Application No. 2006-210183) and Patent Reference 2 (Japanese Published Unexamined Patent Application No. 2002-229022)). A surface lighting device 1 disclosed in Patent Reference 1 is arranged so that a heat-transmitting part 10 a provided in a recessed part 10 formed on the side wall 8 of a frame 6 made of a metallic material will come into contact with a mounting surface 3 d of each of the point light sources 3 thus receiving the light sources 3 in the recessed part 10 . An FPC 4 as a light source substrate and the point light sources 3 are fixed together with a conductive adhesive 12 . The technique disclosed in Patent Reference 1 uses this arrangement to efficiently transmit heat generated by the light emission of the point light source 3 by way of a metallic frame 6 thus enhancing the heat dissipation, which allows the element density of the point light source 3 and the current supplied to each point light source 3 .
[0007] In a backlight device disclosed in Patent Reference 2, a soft metallic sheet 7 for dissipating heat from a light-emitting diode 2 formed in almost the same shape as a film wiring board 4 is bonded with adhesive to a surface opposite to the surface of the film wiring board 4 on which the light-emitting diode 2 is mounted, thus covering a metallic reflector 8 . The technique disclosed in Patent Reference 2 uses this arrangement to effectively transmit heat generated on the light-emitting diode 2 as a light source to the film wiring board 4 and a heat-dissipating member such as the soft metallic sheet 7 without letting the heat fill the backlight device itself.
[0008] However, the light source devices disclosed in Patent Reference 1 and Patent Reference 2 have following disadvantages. For example, although a light source substrate and a heat-dissipating member are fixed together with an adhesive, the adhesive peels off over time.
[0009] When a metallic plate such as an MCPCB (Metal Core Printed-Circuit Board) is used for a light source substrate in order to prevent the peel-off, the resulting cost is higher than that of using an FPC.
[Patent Reference 1] JP-A-2006-210183 (Pages 2-5, FIGS. 1-4)
[Patent Reference 2] JP-A-2002-229022 (Pages 3-7, FIGS. 1-4)
SUMMARY
[0010] The invention has been accomplished in order to solve the problems and is capable of efficiently dissipating heat from a light source substrate directly mounting a point light source. The invention provides a light source device capable of firmly fixing a light source substrate and a heat-dissipating part to each other. The invention further provides a surface light source device mounting the light source device having a structure whereby the light source device is readily replaced with spare without breakage or a wire break.
[0011] The invention provides a light source device comprising: a point light source for emitting light; a light source substrate directly mounting the point light source; a light source substrate cover having a through hole or a notch in a position to which the point light source corresponds, the light source substrate cover arranged opposite to a surface of the light source substrate on which the point light source is mounted; and a support member for supporting the light source substrate, the support member arranged to be opposed to the reverse side of the mounting surface of the light source substrate, the support member has a substantially same size with the light source substrate; wherein the light source substrate cover and the support member sandwich the light source substrate to support the light source substrate.
[0012] The light source device according to the invention comprises: a light source substrate directly mounting a point light source for emitting light; a light source substrate cover including a through hole or a notch in a position to which the point light source corresponds, the light source substrate cover arranged opposite to the surface of the light source substrate on which the point light source is mounted; and a support member for supporting the light source substrate, the support member arranged opposing a surface opposite to the mounting surface of the light source substrate; characterized in that the light source substrate cover and the support member sandwich the light source substrate to support the same. This arrangement efficiently dissipates heat from a light source substrate mounting a point light source.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Illustrative aspects of the invention will be described in detail with reference to the following figures wherein:
[0014] FIG. 1 is an exploded perspective view of a display device according to Embodiment 1 of the invention;
[0015] FIG. 2 is a cross-sectional view of a surface light source device assumed in case the display device in FIG. 1 is assembled, taken in the direction of arrow A-A;
[0016] FIG. 3 is an exploded perspective view of alight source device according to Embodiment 1 of the invention;
[0017] FIG. 4 is an enlarged view of main parts of the light source device according to Embodiment 1 of the invention in an assembled state;
[0018] FIG. 5 is a cross-sectional view of the light source device in FIG. 4 taken in the direction of arrow B-B;
[0019] FIG. 6 is an enlarged view of main parts of the light source device according to Embodiment 1 of the invention;
[0020] FIG. 7 is an exploded perspective view of a surface light source device according to Embodiment 1 of the invention;
[0021] FIG. 8 is an enlarged view of main parts of the light source device according to Embodiment 1 of the invention;
[0022] FIG. 9 is an enlarged view of main parts of the light source device according to Embodiment 1 of the invention;
[0023] FIG. 10 is an enlarged view of main parts of the light source device according to Embodiment 1 of the invention;
[0024] FIG. 11 is an exploded perspective view of a display device according to Embodiment 2 of the invention; and
[0025] FIG. 12 is a cross-sectional view of the display device in FIG. 11 in an assembled state taken in the direction of arrow E-E.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Exemplary embodiments of the invention concerning the configuration of a display device according to the invention and a method for manufacturing the display device will be described referring to drawings. Same signs used across the drawings show substantially the same configuration.
Embodiment 1
[0027] FIG. 1 is an exploded perspective view showing a general configuration of a display device according to the invention. FIG. 2 is a cross-sectional view of the display device in FIG. 1 in an assembled state taken in the direction of arrow A-A. FIG. 3 is an exploded perspective view showing a general configuration of a light source device mounted on the display device according to the invention. FIG. 4 is an enlarged view of main parts of the light source device in an assembled state. FIG. 5 is a cross-sectional view of the light source device in FIG. 4 taken in the direction of arrow B-B.
Embodiment 1
[0028] As shown in FIG. 1 or 2 , a numeral 1 represents a box-shaped rear frame 1 having an opening 1 a. A light source device 31 for emitting light is arranged on an inner side surface 1 b as a side surface of the inner wall of the rear frame 1 . A reflector 2 , which guides light emitted from the light source device 31 toward the opening 1 a, is arranged on the bottom surface 1 c of the inner wall of the rear frame 1 . An almost rectangular light guide plate 7 for propagating, in the shape of a plane, light emitted from the light source device 31 is arranged inside the rear frame 1 . An incidence surface 7 b as a side surface of the light guide plate 7 is arranged in a position opposite to a light-emitting part 31 a of the light source device 31 from which light is emitted. The rear frame 1 is fitted to a front frame 8 including an opening to provide a surface light source device 32 . A display panel 9 and a circuit board 10 for driving and controlling the display panel 9 are arranged on the exit surface of the surface light source device 32 . A front frame 11 including an opening 11 a is fitted to the surface light source device 32 to provide a display device 33 .
[0029] Next, the light source device 31 according to Embodiment 1 will be detailed referring to drawings. As described earlier, in FIG. 1 , the light source device 31 is arranged on the inner side surface 1 b of the rear frame 1 . As shown in FIGS. 3 and 4 , the light source device 31 includes an almost rectangular light source substrate 4 on which point light sources 3 are mounted, a light source substrate cover 5 arranged on the surface 41 of the light source substrate 4 mounting the point light sources 3 , and a support member 6 arranged opposite to a rear surface 42 . The point light source 3 is made of, for example, a light-emitting diode for emitting light of red, green, blue, or white color or an intermediate color thereof. A single point light source or a plurality of point light sources 3 is arranged and mounted on the light source substrate 4 via soldering. In case plural point light sources 3 are mounted, a particular color of light may be selected depending on the application. A combination of colors may be selected as required. The point light sources 3 may be arranged in desired positions and with desired spacing depending on the application or purpose. In Embodiment 1, plural point light sources 3 are mounted on the light source substrate 4 in an almost straight line and with same spacing.
[0030] As shown in FIGS. 2 to 4 , the light source substrate 4 of the light source device 31 includes a recessed part 4 a in a position where a projection 5 b provided on a light source substrate cover 5 and a recessed part 6 a provided on the support member 6 overlap one on the other. The light source substrate 4 maybe a glass epoxy substrate, metal base substrate, a flexible substrate or the like. A wiring pattern (not shown) for feeding power to the point light sources 3 is arranged on the light source substrate 4 .
[0031] As shown in FIGS. 2 to 5 , the light source substrate cover 5 is arranged on the surface 41 of the light source substrate 4 mounting the point light sources 3 . Through holes 5 a are formed on the light source substrate cover 5 , and the through holes 5 a are formed in a position where the through holes 5 a is arranged opposite to the point light sources 3 on the light source substrate 4 . A projection 5 b protruding from a rear surface 52 is arranged between the through holes 5 a, and arranged on the side of a top surface 53 and a bottom surface 54 . As shown in FIG. 5 , the projection 5 b comprises a tip 5 c fitted in a recessed part 6 a provided on the support member 6 . As shown in FIG. 2 , by forming the light source substrate cover 5 thicker than the point light source 3 so that the point light source 3 mounted on the light source substrate 4 will not protrude from the through hole 5 a, as described below, it is possible to prevent the point light source 3 from being damaged while being in contact with the rear frame 1 , front frame 2 , light guide plate 7 or the like upon assembling the light source device 31 into the display device 32 or in an attempt to remove the light source device 31 . The through hole 5 a may be a notch and may have any shape as long as the shape receives a light source. The light source substrate cover 5 is made of a plastic resin, a metal, or a material including a metallic material. The light source substrate cover 5 may be formed of a single member or a combination of plural members. The light source substrate cover 5 desirably includes a surface formed of a high reflection member in a white color or having a mirror surface so that light emitted from the point light source 3 is directed to the light guide plate 7 .
[0032] As shown in FIGS. 2 to 5 , the support member 6 is formed in the same size equal to or larger than that of the light source substrate 4 and arranged on the side of the rear surface 42 of the light source substrate 4 thus preventing warp or displacement of the light source substrate 4 . The top surface 61 and bottom surface 62 of the support member 6 are provided with recessed parts 6 a for fitting to the light source substrate cover 5 . As shown in FIGS. 3 and 5 , the recessed part 6 a is a recessed part 6 a with a different step height on the front surface 63 or on the rear surface 64 , and the recessed part 6 a is formed so that the projection 5 b and the tip 5 c of the light source substrate cover 5 will not protrude from the rear surface 64 and the top surface 61 of the support member 6 . While the support member 6 may be formed of a plastic resin, the support member 6 may be formed of a metal with high thermal conductivity including aluminum, stainless steel, iron or copper, or a material including such a metal in order to enhance the heat dissipating effect. The support member 6 may be formed of a single member or a combination of plural members.
[0033] Next, a method for assembling the light source device 31 will be described referring to FIG. 3 . First, the light source device 31 is arranged so that the rear surface 42 of the light source substrate 4 mounting the light sources 3 will overlap the front surface 63 of the support member 6 . Next, arrangement is made so that the recessed part 4 a of the light source substrate 4 will match the recessed part 6 a of the support member 6 . Next, the through holes 5 a of the light source substrate cover 5 are arranged so as to fit over the point light sources 3 . The projection 5 b is aligned with the position of the support member 6 where the recessed part 6 a of the support member 6 is formed and the projection 5 b and the tip 5 c are fitted in the recessed part 6 a. In this procedure, a double-faced tape, an adhesive, or grease with high thermal conductivity may be used to fix the light source substrate 4 to the support member 6 . This enhances adhesion of the light source substrate 4 to the support member 6 thus improving the heat dissipation. Even in case an adhesive is degraded over time, it is possible to firmly fix the light source substrate 4 and the support member 6 together by fitting and fixing the members to each other.
[0034] As shown in FIGS. 3 and 5 , in the light source device 31 , at least two fitting parts formed of the projection 5 b and the tip 5 c of the light source substrate cover 5 , the recessed part of the light source substrate 4 , and the recessed part 6 a of the support member 6 are formed at each member to fix the members. By arranging the fitting parts in four positions, that is, two positions on the top surface ( 53 , 61 ) and two positions on the bottom surface ( 54 , 62 ), fixing of the members are made reliable.
[0035] While the projection 5 a and the tip 5 c for fitting are provided on the light source substrate cover 5 and the recessed part 6 a for fitting is provided on the support member 6 in this embodiment, the recessed part may be provided on the light source substrate cover 5 and the projection and tip may be provided on the support member 6 . In this way, the positions and numbers of fitting parts may be arbitrarily changed.
[0036] As shown in FIG. 6 , a projection 5 d for positioning is arranged on the light source substrate cover 5 and positioning holes for the projection 5 d are provided in the light source substrate 4 ( 4 b ) and the support member 6 ( 6 b ). They are separately from the above-described fitting part and positioning. By forming the projection for positioning and corresponding positioning holes and performing positioning, it is possible to prevent displacement of the light source substrate cover 5 , light source substrate 4 and support member 6 that could occur in the process of assembling the light source device 31 and the process of assembling the display device 33 . While a projection is provided on the light source substrate cover 5 in this example, positions and shapes of a projection for positioning and positioning holes maybe changed as required. For example, a projection may be provided on the support member 6 .
[0037] Next, a method for assembling the light source device 31 of Embodiment 1 into the display device 33 will be described. FIG. 7 is an enlarged view of main parts assumed when the light source device 31 is assembled into the surface light source device 32 .
[0038] As described above, in the light source device 31 , the light source substrate cover 5 and the support member 6 sandwich the light source substrate 4 to support the same so as to firmly fix the light source substrate 4 and the support member 6 together. It is thus possible to move the light source device 31 along the inner side surface 1 b of the rear frame 1 to assemble the light source device 31 into the surface light source 32 . Before the light source device 31 is assembled along the inner side surface 1 b, a through hole 12 for inserting the light source device 31 is formed in the side surface 1 d of the rear frame 1 and the side surface of the front frame 8 of the surface light source device 32 . The light source device 31 is inserted from the through hole 12 , along the inner side surface 1 b of the rear frame 1 in the direction of arrow C. In case the light source device 31 is faulty and must be replaced with spare, the light source device 31 may be readily removed by pulling it out of the through hole 12 in the direction of arrow D. In FIG. 1 , if wishing to arrange the light source device 31 in a replaceable fashion in the display device 33 , a through hole is formed in the front frame 11 in a position corresponding to the through hole 12 .
[0039] As described above, the light source device 31 according to the invention includes a light source substrate 4 mounting the light sources 3 . The light source substrate cover 5 is arranged on the surface 41 of the light source substrate 4 mounting the point light sources 3 . The support member 6 is arranged on the rear surface 42 . The light source substrate cover 5 and the support member 6 sandwich the light source substrate 4 to support the same, which prevents deformation of or slack in the light source substrate 4 and efficiently transmits heat from the point light sources 3 to the support member 6 . The projection 5 b and the tip 5 c of the light source substrate cover 5 are matched with the position of the support member 6 where the recessed part 6 a is formed. The projection 5 b and the tip 5 c are fitted in the recessed part 6 a and the members are fixed together, thus firmly fixing the light source substrate 4 to the support member 6 . Further, the light source device 31 may be inserted/removed into/from the through hole 12 provided in the surface light source device 32 . It is thus possible to readily replace the light source device 31 with spare in case the light source device 31 has gone faulty.
[0040] As shown in the enlarged view of main parts of FIG. 8 , as a variation of the light source device 31 of this embodiment, a tapered part 5 g is provided at the through hole 5 a of the light source substrate cover 5 for receiving the point light source 3 . The tapered part 5 g is arranged on the inner side surface forming the through hole 5 a provided in the light source substrate cover 5 , so as to slant the through hole 5 a and enlarge the same from the rear surface 52 as a surface opposite to the mounting surface 41 of the light source substrate 4 toward the front surface 51 as a surface opposite to the rear surface 52 . When the light source device 31 including the tapered part 5 g is assembled into the display device 33 shown in FIG. 1 , light emitted from the point light source 3 may be reflected on the tapered part 5 g to be directed to the light guide plate 7 . This eliminates reflection losses at the light source substrate cover 5 and efficiently causes light emitted from the point light source 3 to be incident on the light guide plate 7 .
[0041] As shown in the enlarged view of main parts of FIG. 9 , as another variation of the light source device 31 of this embodiment, a chamfered part 5 f is formed at an end of the light source substrate cover 5 . The chamfered part 5 f is formed at the insertion-starting end of the light source substrate cover 5 before the light source device 31 is inserted from the through hole 12 so as to enhance the workability. Further, as shown in FIG. 10 , a projecting part 5 e is arranged at an end of the light source substrate cover 5 where insertion of the light source device 31 is finished. By arranging the projecting part 5 e, it is possible to prevent leakage of light from the through hole 12 as well as cause light destined to the projecting part 5 e to reflect toward the light guide plate 7 .
[0042] While the light source device 31 is arranged on one side of the inner side surface 1 b of the rear frame 1 in this embodiment, the light source devices 31 may be arranged on two to four sides to enhance and make uniform the luminance.
[0043] The rear frame 1 is made of a metal with high thermal conductivity including aluminum, stainless steel, iron or copper, or a plastic resin. The rear frame 1 may be composed as a single member or a combination of plural members as required.
[0044] The front frame 8 is made of a metal with high thermal conductivity including aluminum, stainless steel, iron or copper, or a plastic resin. The front frame 8 may be composed as a single member or a combination of plural members as required.
[0045] A display panel 9 may be a liquid crystal panel. A liquid crystal panel is composed of a pair of reflectors sandwiching in a bonding fashion a pair of glass substrates (top and bottom) which are sealed with a sealant and between which a liquid crystal is injected. The display panel 9 is coupled to a circuit board 10 , such as a flexible substrate on which a driving IC chip is mounted, for driving and controlling the display panel 9 .
[0046] An optical sheet such as a diffusion sheet, a prism sheet or a polarization reflection sheet, or a plate-shaped light diffusion member is arranged between the display panel 9 and the light guide plate 7 in order to enhance the display performance.
[0047] The material of the light guide plate 7 is generally a highly transparent material such as PMMA (Polymethylmethacrylate) or PC (Polycarbonate). It is favorable to provide a certain amount of distance between the point light source 3 and the light guide plate 7 in order to prevent degradation of the light guide plate 7 attributable to heat from the point light source 3 in use under high temperatures. As in Embodiment 1, it is possible to provide a certain amount of distance between the point light source 3 and the light guide plate 7 by providing the light source substrate cover 5 with a thickness greater than that of the point light source 3 .
Embodiment 2
[0048] FIG. 11 is an exploded perspective view of a display device showing according to Embodiment 2 of the invention. FIG. 12 is a cross-sectional view of the display device in FIG. 11 in an assembled state taken in the direction of arrow E-E. As shown in FIGS. 11 and 12 , a light source device 34 in Embodiment 2 includes a support member 6 arranged on the rear surface 42 of the light source substrate 4 but does not include a light source substrate cover 5 such as one in Embodiment 1 arranged on the surface 41 of the light source substrate 4 mounting point light sources 3 . The light source device 34 is fitted to a projection 1 f formed on the rear frame 1 and a recessed part 8 b formed of the rear frame 1 and a front frame 8 to support the light source substrate 4 and the support member 6 . Embodiment 2 is different from Embodiment 1 only in that the light source device 34 is fitted to the projection 1 f formed on the rear frame 1 and the recessed part 8 b formed of the rear frame 1 and the front frame 8 to support the light source substrate 4 and the support member 6 . The remaining configuration is the same as that of Embodiment 1.
[0049] In FIGS. 11 and 12 , a projection 1 f is formed on part of a bottom surface 1 c opposite to the opening 1 a of the rear frame 1 , and the projection 1 f includes one side of the bottom surface 1 c and forms convex from inside to outside. By fitting the light source device 34 to the inner wall of the projection 1 f, the light source substrate 4 and the support member 6 are supported. In the process, the support member 6 is arranged opposite to the inner side surface 1 b of the rear frame 1 . The mounting surface 41 of the light source substrate 4 is arranged opposite to a support part 1 e forming part of the projection 1 f.
[0050] A recessed part 8 b is formed of an inner side surface 1 b of the rear frame 1 and part of the side surface 8 a of the front frame 8 having a side surface 8 a arranged in opposite position and fitted to the inner side surface 1 b of the rear frame 1 . The light source device 34 is fitted in the recessed part 8 b. The mounting surface 41 of the light source substrate 4 is arranged opposite to the support part 8 c formed at the recessed part 8 b and fits, together with the inner side surface 1 b of the rear frame 1 , the light source substrate 4 and the support member 6 and supports them.
[0051] The method for assembling the light source device 34 into the surface light source device 32 according to Embodiment 2 fits the light source device 34 to the inner wall of the projection 1 f formed on part of the bottom surface 1 c of the rear frame 1 . In the process, the support member 6 is arranged opposite to the inner side surface 1 b of the rear frame 1 . The mounting surface 41 of the light source substrate 4 is arranged opposite to a support part 1 e forming part of the projection. Next, a reflector 2 and a light guide plate 7 are arranged. The front frame 8 is fitted to the rear frame 1 and the light source device 34 is fitted in the recessed part 8 b.
[0052] As described above, the surface light source device 32 according to Embodiment 2 forms, on part of a bottom surface 1 c opposite to the opening 1 a of the rear frame 1 , a projection 1 f including one side of the bottom surface 1 c and becoming convex from inside to outside and fits the light source device 34 in the recessed part 8 b to the inner wall of the projection 1 f and in the recessed part 8 b formed of the rear frame 1 and the front frame 8 . This firmly fixes the light source substrate 4 and the support member 6 .
[0053] The projection 1 f formed on the bottom surface 1 c of the rear frame 1 may be arranged along the light source substrate 4 or support part of the light source substrate 4 . In Embodiment 2, while the light source device 34 is supported by fitting the light source device 34 to the projection 1 f formed on the rear frame 1 or in the recessed part 8 b formed of the rear frame 1 and the front frame 8 , any shape may be used as long as the shape allows fitting of the light source device to the rear frame 1 and the front frame 8 . The position where the recessed part 8 b is formed may be changed in various ways.
[0054] The support member 6 may be fixed to the rear frame 1 via a screw or an adhesive so as to dissipate heat from the light source substrate 4 via the support member 6 .
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A light source device comprising: a point light source for emitting light; a light source substrate directly mounting the point light source; a light source substrate cover having a through hole or a notch in a position to which the point light source corresponds, the light source substrate cover arranged opposite to a surface of the light source substrate on which the point light source is mounted; and a support member for supporting the light source substrate, the support member arranged to be opposed to the reverse side of the mounting surface of the light source substrate, the support member has a substantially same size with the light source substrate; wherein the light source substrate cover and the support member sandwich the light source substrate to support the light source substrate.
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BACKGROUND OF THE INVENTION
The present invention relates to a prefabricated window system, and more particularly to a prefabricated window system having a main frame and other elements including a sill which are fabricated from extruded thermoplastic members.
Prefabricated windows are frequently used, both for new construction and replacement purposes, in order to provide high quality at a moderate cost. The desireable attributes of a prefabricated window are easier to state than to achieve. The window should be relatively inexpensive both to purchase and to install, but it should nevertheless offer excellent security against the elements. Furthermore the window should be attractive and sufficiently rugged to withstand abuse. Finally, these qualities should be present not only at the time of installation but for many years thereafter.
The S 771 (™) prefabricated window system of Rehau Incorporated, having an office in Leesburg, Va., achieves the aforesaid qualities to an admirable degree. The S 771 window is described in a pending application, Ser. No. 06/929,303, filed Nov. 12, 1986, which is incorporated hereby by reference. Briefly, the window system disclosed in this application includes a rectangular main frame having a top frame portion, a bottom frame portion, and two side frame portions. The frame portions are made from extruded vinyl and all have the same cross-sectional configuration or profile except for features such as drainage channels which are fabricated after extrusion. The side frame portions provide channels for guiding two window sashes and a screen member, and since the top and bottom frame portions have the same cross-sectional configuration as the side frame portions such channels are also present in the top and bottom frame portions. Primarily to improve the appearance of the window, a snap-in decorative panel covers one of the window channels in the top frame portion. An extruded vinyl sill having closed internal compartments is provided at the bottom frame portion. The sill has resilient legs by which the sill is snap-connected to flanges which extend into the window channels of the bottom frame portion. The sill covers the window channels of the bottom frame portion.
In the window system of the aforesaid pending application, the screen channel of the bottom frame portion is exposed to the elements. While water can be drained by drilling a bore through the screen channel, it has been found that debris occasionally accumulates in the screen channel of the bottom frame portion to an undesirable degree. Unless such debris is cleared away, either by the rain or the homeowner, it may collect in uneven piles which prevent the screen member from being fully lowered. Thus the accumulated debris is not only unsightly, in extreme cases it may cause gaps at the bottom edge of the screen member and thus permit insects to enter the house.
SUMMARY OF THE INVENTION
One object of the invention is to provide a prefabricated window system having a main frame with a screen channel which does not collect debris.
Another object of the invention is to provide a prefabricated window system having an improved sill which is connected to a bottom portion of a main frame and which overhangs and thus shields a screen channel in the bottom portion.
These and other objects which will become apparent in the ensuing detailed description can be attained by providing a prefabricated window system having a main frame which is made from extruded thermoplastic frame portions having substantially the same cross-sectional configuration. At the sides of the main frame, the frame portions provide channels for guiding two window sashes and a screen member. A sill has resilient legs which snap into flanges extending into the window channels of the bottom frame member. The sill also has an overhanging portion which covers the screen channel in the bottom frame portion to shield it from debris. To help brace the sill, the overhanging portion has downwardly extending flanges which overlap walls of the bottom frame portion adjacent the screen channel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a window system in accordance with the present invention in its un-installed state;
FIG. 2 is a rear view of the window system in its un-installed state;
FIG. 3 is a perspective view of the window system in its un-installed state;
FIG. 4 is a sectional view, taken along line 4--4 of FIG. 1, illustrating the window system in its installed state;
FIG. 5 is a sectional view, taken along line 5--5 of FIG. 1, illustrating the window system in its installed state;
FIG. 6 is a top plan view of one end of the sill and a sectional view through one side frame portion of the window system, which is installed in an alternate manner.
FIG. 7 is a sectional view through the bottom frame portion and the sill; and
FIG. 8 is a sectional view of a nailing fin employed in FIG. 4 and 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A window system in accordance with the present invention is illustrated generally in FIG. 3 in its un-installed state, and includes a main frame 10 having side frame portions 12 and 14, a top frame portion 16, and a bottom frame portion 18. The window system also includes top window 20, bottom window 22, and screen member 24, which are slidably mounted in channels provided by side frame portions 12 and 14. A sill 26 is mounted on bottom frame portion 18, and a decorative panel 28 (see FIG. 1) is mounted on top frame portion 16. Stop elements 30 are mounted in side frame portions 12 and 14 to prevent bottom window 22 from being moved upwards far enough to smash into the handle 32 (see FIG. 1) of top window 20, and to prevent top window 20 from being moved downward far enough for handle 32 to smash into bottom window 22. The window system also includes window mounting means, which will be described later, and hardware such as keeper 34, latch 36, buttons 38 for actuating retractable tilt latch mechanisms 40, and balance mechanisms 42. Typically either two balance mechanisms 42 (one on each side) or four (two on each side) are used with each of windows 20 and 22, depending on their size and weight. Each balance mechanism 42 includes spring (not illustrated) which is coiled within a tube 44 and which is connected via a link 46 to a slidably mounted window attachment mechanism 48 (FIG. 5). Pivot bars 50 (see FIG. 5) extend from the bottom of either window to engage mechanisms 48.
FIG. 7 illustrates a cross-sectional view of sill 26 and bottom portion 18 of frame 10. Frame 10 is preferably fabricated from a length of an extruded thermoplastic such as vinyl which is cut into sections for use as frame portions 12, 14, 16, or 18. That is to say, each of these portions has the same general cross-sectional configuration, although for purposes of description the configuration illustrated in FIG. 6 has been identified as portion 18. Portion 18 in FIG. 6 could alternatively have borne reference number 12, 14, or 16.
Frame portion 18 includes a wall 52 which faces the interior of the building in which the window system is installed and a wall 54 which faces the outside. An inner wall 56 faces the interior of frame 10 (see FIG. 3) and is attached to wall 54. Walls 58 and 60, which are connected by a bridge 62, are supported by wall 56. A sloping web 66 connects wall 54 to a wall 68, which terminates at intermediate wall 70. Wall 71 extends outward from wall 70 and has a slot 72. Walls 76 and 78 are disposed behind slot 72 to provide a chamber into which slot 72 communicates. In a similar manner wall 52 is interrupted by a slot 80 which is closed off by walls 84 and 86. Outer wall 87 faces away from the interior of frame 10 (see FIG. 3) and connects wall 52 to wall 71.
With continuing reference to FIG. 7, wall 88 extends between wall 56 and wall 70. An intermediate wall 90 connects wall 88 to wall 92, which extends inward from wall 70. A flange 96 is connected to wall 88, and wall 56 terminates at a flange 98. Wall 92 extends to a wall 102, which terminates in a flange 104. Connected to wall 92 is a flange 106 parallel to flange 104. A step 108 connects wall 102 to a wall 110 having a flange 112. A flange 114 extends from a wall 116, which connects wall 110 to wall 70. Facing wall 116 is a wall 118 having a flange 120. A wall 122 connects wall 52 to wall 118 and terminates in a flange 123.
It will be apparent that the various walls and panels heretofore described provide channels 124, 126, and 128, along with various chambers as illustrated.
Two grooves 142 are molded into wall 90 and into wall 70. Also molded into wall 90 and wall 70 are a pair of screw bosses 146 corresponding to each groove 142.
The features identified by reference numbers 52 through 146 are present in each of frame portions 12, 14, 16, and 18 (see FIG. 3). However not all of these features are utilized in the same way in each of the frame portions. For example, grooves 142 and screw bosses 146 have no function in top frame portion 16 and bottom frame portion 18, and are present in these frame portions only because of their utility in side frame portions 12 and 14. The tubes 44 (see FIG. 3) of balance mechanisms 42 are attached to side frame portions 12 and 14 and grooves 142 and bosses 146 are used to facilitate this attachment. The tubes 44 are secured to frame portions 12 and 14 by sheet metal screws (not illustrated). Grooves 142 and bosses 146 extend the entire length of side frame portions 12 and 14 (as, indeed, they extend the entire lengths of top and bottom frame portions 16 and 18), and accordingly during fabrication of the window system a screw can be slid to the desired height along a groove 142 and then screwed in with confidence that it is aligned with bosses 146 on the other side to reliably secure the screw. Although two grooves 142 and their corresponding bosses 146 are provided in each of channels 126 and 12 in FIG. 7, and only one tube 44 is mounted in each of the corresponding channels of FIG. 5, it will be recalled that additional balance mechanisms may be needed with large windows.
Referring next to FIGS. 1, 2, and 3, frame portions 12, 14, 16, and 18 are joined at the corners by interior welds 193, exterior welds 194, and lateral welds 196, and these corner welds imparting both rigidity and a finished appearance to main frame 10. In this context the term "weld" means that the corners have been joined by molten thermoplastic which, when it cools, seals one frame portion with an adjacent portion along a smooth seam. Panel 28 and stop elements 30 are not welded to main frame 10. Although not illustrated, one side of panel 28 has resilient legs which snap onto flanges 112 and 123 (see FIG. 7) of top frame portion 16, thereby covering channel 128. This increases the aesthetic appeal of the window system. Stop elements 30 also have resilient legs (not illustrated) which permit them to be snap-connected to side frame portions 12 and 14. Panel 28 and stop elements 30 preferably have the same cross-sectional configuration, so that either can be cut from a length of extruded vinyl. At the bottom of main frame 10, frame portion 18 preferably has drainage channels (not illustrated) which are drilled after extrusion. With reference to FIG. 7, holes are preferably drilled into wall 68, 88, 92, and 116, just above wall 70, and into wall 90 at the bottom of channel 126, to provide such drainage.
With continuing reference to FIG. 7, sill 26 is fabricated from an extruded length of vinyl having the cross section or profile illustrated. Sill 26 includes an inner wall 150 from which extend bracket portions 152 which are spaced apart to define a slot 154. A brush seal 155 (see FIG. 4) is inserted into slot 154. A bottom wall 156 is connected between wall 150 and an intermediate Wall 158, thereby providing a sash-receiving trough 160. A sloping web 162 extends from intermediate wall 158 and terminates in an overhang portion 164.
Gripper flanges 166 and 168 extend downward from the underside of overhang portion. Also extending downward from the underside of sill 26 are resilient legs 170 and 171, which are provided respectively with hooks 172 and 173. Flanges 174 and 175 extend downward from wall 156, which terminates in an end flange 176. Flanges 175 and 176 define an L-shaped support bracket 177.
Referring next to FIGS. 4 and 7 together, the installation of sill 26 on bottom frame portion 18 will now be described. Sill 26 is snap-connected to frame portion 18 by being forced downward. As this occurs, leg 170 is bent slightly counterclockwise by the edge of flange 9 and leg 171 is bent slightly clockwise by the edge of flange 123. With further downward movement, hook 172 clears flange 98 and leg 170 snaps back so that hook 172 latches against the underside of flange 98. Similarly, hook 173 latches against the underside of flange 123. In this installed position, the bottom portion of wall 150 overlaps the outer side of wall 52; the end of flange 174 rests on wall 122 immediately above wall 118; support bracket 177 fits over the corner at the intersection of wall 102 and step 108; and the underside of overhang portion 164 rests on the top of wall 54 and bridge 62, with gripper flanges 166 and 168 overlapping the sides of walls 54 and 60. As a result, sill 26 is solidly supported on bottom frame portion 18. Hooks 172 and 173 prevent sill 26 from being inadvertently raised. Flanges 166, 168, and 175 prevent lateral movement of sill 126, as does the bottom portion of wall 150. Finally, sill 26 is supported from below at overhang portion 164, support bracket 177, and flange 174. This support from below keeps the vinyl of sill 26 from being bent even if significant downward force is exerted on it.
Referring next to FIGS. 3, 4, and 5, window 22 includes a sash 198 in which an insulated glazing unit 200 (which includes two panes of spaced-apart glass) is mounted. Weather proofing elements such as brush seals 202 are mounted at the edges of sash 198. Top window 20 similarly includes a sash 206, glazing unit 208, and brushed seals 203.
Each of sashes 198 and 206 includes four sash portions 210 of extruded thermoplastic, sash portions 210 being welded to one another at the corners. A cover element 260 is snap-connected to the top sash portion 210 of sash 198 and, although not illustrated, a similar cover element is snap-connected to the bottom sash portion 210 of sash 206. These cover elements are preferably provided with interlock lips which cooperate when windows 20 and 22 are in the closed position to inhibit air incursion. Cover element 260 has openings through which buttons 38 protrude.
Glazing beads 212 hook on to the sash portions 210 at the indoor sides thereof. Resilient glazing splines 256 are mounted on glazing beads 212 and on the outdoor sides of sash portions 210. Tubes 266 extend through the bottom sash portion 210 of each window to drain any condensation or any water which may have leaked through glazing splines 256.
FIGS. 4 and 5 are sectional views taken respectively along lines 4--4 and 5--5 of FIG. 1, except that screen member 24 is not shown and the window system has been installed in a building. In FIGS. 4 and 5, interior and exterior panels 286 and 288 are supported by framing members such as two by fours 290. During construction an opening is left for the window system, and the interior portion of this opening is lined with strips 292. Internal trim 294 is also attached. After this preparation has been completed, the window system is inserted into the opening through the outer side of the wall, with shims 296 being used to avoid gaps. Nailing fins 298 are plugged into main frame 10, as will be discussed, and are secured to the wall by nails 300. Thereafter outer siding 302 is applied and the window system is sealed thereto by caulk 304. It will be apparent that differences in construction and material may lead to variations in the installation procedure that has been described.
Because of the reduced scale of FIGS. 4 and 5 it is appropriate to continue the discussion of nailing fin 298 with reference to FIG. 8. Nailing fin 298 is preferably an extruded thermoplastic element having a cross-sectional configuration as illustrated. An attachment portion 306 is connected to an outwardly extending portion 308, which in turn is connected by a bridge portion 310 and an insertion portion 312 to an arrowhead portion 314. During installation of nailing fin 298, extending portion 308 is pressed against wall 87 (see FIG. 7) of the appropriate frame portion 12, 14, 16, or 18, with arrowhead portion 314 poised to enter the slot 72 (see FIG. 7). The bridge portion 310 is then pounded with a rubber mallet (not illustrated) to drive arrowhead portion 314 through slot 72. The nails 300 are driven through attachment portion 306 as previously discussed.
While slot 72 is provided to receive nailing fin 298, slot 80 (see FIG. 7) is not present for this purpose. Slot 80 is provided for use in the event that two windows systems are to be mounted side-by-side. In this case, a tying element (not illustrated) is pounded into the slot 80 of one window system and into the slot 80 of the adjacent window system. A similar tying element (not illustrated) connects the adjacent slots 72 on the outside of the window systems.
Installation of the window system as shown in FIGS. 4 and 5, with the aid of nailing fin 298, is primarily intended for new construction. FIG. 6 illustrates the window installed as a replacement for a wooden window (not illustrated) that was previously present. In this situation structures such as window ledge 322 may remain from the previous installation. Frame 10 is centered in the opening with the aid of shims 332, and is mounted by driving nails 324 through holes (not illustrated) provided in frame 10. Additionally, inner and outer strips 328 and 330, caulk 333, and external trim 334 are installed.
Referring to FIGS. 6 and 7 together, at each end of sill 26 there is a tab 350 which extends into channel 128, a tab 352 which extends into channel 126 beneath stop element 30, and a tab 354 which extends into channel 124.
It will be understood that the above description of the present invention is susceptible to various modifications, changes, and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A prefabricated window system includes a rectangular main frame having a top frame portion, a bottom frame portion, and two side frame portions. The frame portions are extruded thermoplastic elements having substantially the same cross-sectional configuration. The frame portions include first and second channels which, in the side frame portions, serve to guide windows. The frame portions also provide a third channel which, in the side frame portions, serve to guide a screen member. The window system also includes a sill which is connected to the bottom frame portion. The sill includes an extruded thermoplastic element which is snap-connected to the bottom frame portion and which is braced with respect to the bottom frame portion. The sill covers the window channels of the bottom frame portion, and additionally has an overhang portion which covers the screen channel of the bottom frame element to keep debris out. The sill also has a trough for receiving the bottom edge of one of the windows when it is closed, and a seal which is directed toward the trough to limit air incursion.
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[0001] The entire disclosure of Japanese Patent Application No. 2008-060131 and No. 2008-060132, both filed on Mar. 10, 2008, including specification, claims, drawings and abstract is incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] One aspect of the present invention relates to an information processing apparatus, and in particular, to an information processing apparatus that uses an organic EL device as a display.
[0004] 2. Description of the Related Art
[0005] Recently, a mobile phone, which is an example of an information processing apparatus, is configured not only to a simple communication function by telephone call but also to have an address book function, a mail function through a network, such as a base station or Internet, a browser function for reading Web pages, a music control function for listening to audio data, and a function for receiving terrestrial digital one-segment broadcasting. The mobile phone is configured to play received images based on a terrestrial digital one-segment broadcasting or various video contents acquired by other devices.
[0006] Accordingly, a user has a growing need for watching the video contents better. In order to meet the user's need, a recent mobile phone is suggested in which a high-brightness device, such as an organic EL device, is substituted for a Thin Film Transistor (TFT) liquid crystal display, which has been widely used hitherto. The organic Electronic Luminescent (EL) device is a display device that performs display by using an organic material, which emits light when a voltage is applied. In the organic EL device, an organic material of diamine series is deposited on a glass surface, and is self-luminous. For this reason, the organic EL device can be reduced in thickness, as compared with the known display device.
[0007] In the organic EL device, vivid display is achieved with high-brightness, but the organic material constituting the organic EL element may be deteriorated due to heat caused by light-emission since the light-emitting layer of the organic EL device is self-luminous. The deterioration of the organic material causes a decrease in light-emission brightness in the organic EL element and unstable light-emission. Furthermore, if the organic EL elements are continuously driven for a long time to display a same image at a same position on a screen, the screen may be burned.
[0008] If the screen is burned, it is difficult to use the mobile phone as a product. Accordingly, in order to prevent the screen from being burned, it is necessary to improve the device, such as an organic EL device, or to perform software control.
[0009] For this purpose, a technology is suggested in which the display device is divided into a plurality of display areas, and a display area for image information display is changed in accordance with temporal information (see JP-A-2003-223160, for instance). According to the technology disclosed in JP-A-2003-223160, it is possible to suppress current consumption and to prevent the display device from being burned.
[0010] According to the technology disclosed in JP-A-2003-223160, a display area for image information display can be changed to one of a plurality of prescribed display areas in accordance with temporal information. In this case, however, the display area of image information cannot but be changed to a prescribed display area. Of course, in the technology described in JP-A-2003-223160, a plurality of prescribed display areas may be appropriately changed in a pixel unit in accordance with the user's preference. In this case, it is time-consuming for the user to appropriately change the display area in a pixel unit in order to suppress occurrence burning in the screen, and it is not preferable in usability. In addition, the change of the display area for image information according to temporal information for every predetermined time results to an increase in power consumption.
[0011] Further, according to the technology disclosed in JP-A-2003-223160, a display area for image information display can be changed to another display area from among a plurality of prescribed display areas in accordance with the temporal information. However, when a same wallpaper is set on a standby screen for a long time, the screen may be burned.
SUMMARY
[0012] According to a first aspect of the invention, there is provided an information processing apparatus including: a display configured to include a display screen and to display image information at a display position on the display screen, the display screen having a plurality of pixels arranged in a matrix, the display position represented by pixel-based coordinates; a calculation module configured to calculate coordinates of a next display position at which the image information is to be displayed next based on coordinate information of the display position and differential coordinate information, the coordinate information representing a position where the image information is to be displayed, the differential coordinate information representing a pixel-based distance with which the display position shifts; and a display control module configured to control the display to display the image information at the next display position based on the coordinate thereof.
[0013] According to a second aspect of the invention, there is provided an information processing apparatus including: a setting module configured to set a wallpaper from among a plurality of wallpapers on a standby screen; a timer configured to measure an accumulation time from a time when the wallpaper is set; a determination module configured to determine whether or not the accumulation time associated with the wallpaper exceeds a given time; a management module configured to manage the accumulation time associated with each of the wallpapers; and a selection module configured to select a settable wallpaper whose accumulation time does not exceed the given time, wherein the setting module is configured to set the settable wallpaper on the standby screen.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Embodiments may be described in detail with reference to the accompanying drawings, in which:
[0015] FIGS. 1A and 1B are exemplary outer appearances of a mobile phone according to a first and a second embodiments of the invention;
[0016] FIGS. 2A and 2B are exemplary another outer appearances of the mobile phone;
[0017] FIG. 3 is an exemplary block diagram showing an internal configuration of the mobile phone;
[0018] FIG. 4 is an exemplary flowchart illustrating an image information display position change processing in the mobile phone of FIG. 3 according to the first embodiment;
[0019] FIG. 5 is an exemplary explanatory view illustrating a shift of a display position in a pixel unit according to the image information pixel position change processing of FIG. 4 ;
[0020] FIG. 6 is an exemplary flowchart illustrating a wallpaper change processing in the mobile phone of FIG. 3 according to the second embodiment;
[0021] FIGS. 7A to 7C are exemplary diagrams showing an example of an accumulation time management table stored in a storage unit according to the second embodiment; and
[0022] FIG. 8 is an exemplary flowchart illustrating another wallpaper change processing in the mobile phone of FIG. 3 according to the second embodiment.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0023] Embodiments of the invention will now be described with reference to the drawings.
[0024] FIGS. 1A and 1B show outer appearances of a mobile phone 1 , which can be applied as an information processing apparatus according to the first and second embodiments of the invention. FIG. 1A shows an outer appearance of the mobile phone 1 in a state where it is unfolded 180 degrees as viewed from a front. FIG. 1B shows an outer appearance of the mobile phone 1 in a state where it is unfolded as viewed from a side.
[0025] As shown in FIGS. 1A and 1B , in the mobile phone 1 , a first casing 12 and a second casing 13 are hinged by a hinge 11 at its central portion. The mobile phone 1 is configured to be foldable in a direction of an arrow X through the hinge 11 . An antenna (an antenna 31 of FIG. 3 described below) for transmission/reception is provided at a predetermined position in the mobile phone 1 . With the internal antenna, the mobile phone 1 transmits and receives an electric wave to and from a base station (not shown).
[0026] On a surface of the first casing 12 , operating keys 14 , such as numeric keys of “0” to “9”, a call key, a redial key, an end/power key, a clear key, an email key, and the like are provided. Various instructions can be input by using the operating keys 14 .
[0027] At an upper portion of the first casing 12 , a directional key and an enter key are also provided as operating keys 14 . A user operates the directional key in a vertical or horizontal direction, thereby moving a cursor in the vertical or horizontal direction. Specifically, various operations, such as a scroll operation of a directory or an email displayed on a main display 17 provided in a second casing 13 , a page rolling operation of a simplified homepage, and a forwarding operation of an image, are performed.
[0028] Various functions can be determined by pressing the enter key. For example, according to the operation of the directional key in the first casing 12 by the user, a desired telephone number is selected from among a plurality of telephone numbers of the directory displayed on the main display 17 . Then, if the enter key is pressed in an inner direction of the first casing 12 , the selected telephone number is determined, and then a call request processing of the telephone number is performed.
[0029] In the first casing 12 , an email key is provided on a left of the directional key and the enter key. If the email key is pressed in an inner direction of the first casing 12 , a mail transmission/reception function can be called. On a right of the directional key and the enter key, a browser key is provided. If the browser key is pressed in the inner direction of the first casing 12 , data of Web pages can be read.
[0030] In the first casing 12 , a microphone 15 is also provided below the operating keys 14 . With the microphone 15 , a user's voice during calling is collected. In the first casing 12 , a side key 16 is also provided to operate the mobile phone 1 .
[0031] A battery pack (not shown) is provided at a rear of the first casing 12 . If the end/power key is put in an ON state, power is supplied to individual circuits from the battery pack, such that the mobile phone 1 starts to operate.
[0032] Meanwhile, the main display 17 is provided at a front of the second casing 13 . On the main display 17 , in addition to a reception state of an electric wave, a remaining battery charge, names or telephone numbers of persons to call or telephone numbers registered in the directory, and a transmission history, the content of an email, a simplified homepage, an image captured by a Charge Coupled Device (CCD) camera (a CCD camera 20 of FIG. 2 described below), contents received from an external contents server (not shown), and contents stored in a memory card (a memory card 46 of FIG. 3 described below) can be displayed. A receiver 18 is provided at a predetermined position above the main display 17 . With the receiver 18 , the user can perform a voice call. A speaker (not shown), other than the receiver 18 , serving as a voice output unit is provided at a predetermined position of the mobile phone 1 .
[0033] Magnetic sensors 19 a, 19 b, 19 c, and 19 d are provided at predetermined positions of the first casing 12 and the second casing 13 so as to detect the state of the mobile phone 1 . The main display 17 is configured by, for example, an organic EL device.
[0034] FIGS. 2A and 2B show another outer appearances of the mobile phone 1 , which can be applied as an information processing apparatus according to the first and second embodiments of the invention. In FIGS. 2A and 2B , the mobile phone 1 is rotated in the direction of the arrow X from the state of the mobile phone 1 shown in FIGS. 1A and 1B . FIG. 2A shows an outer appearance of the mobile phone 1 in a state where it is folded as viewed from the front. FIG. 2B shows an outer appearance of the mobile phone 1 in a state where it is folded as viewed from the side.
[0035] At an upper portion of the second casing 13 , a CCD camera 20 is provided. With the CCD camera 20 , a desired subject can be captured. A sub display 21 is provided below the CCD camera 20 . On the sub display 21 , an antenna pict indicating a current sensitivity level of the antenna, a battery pict indicating a current remaining battery charge of the mobile phone 1 , and a current time are displayed. Similarly to the main display 17 , the sub display 21 is configured by an organic EL device.
[0036] FIG. 3 shows an internal configuration of the mobile phone 1 , which can be applied as an information processing apparatus according to the first and second embodiments of the invention. A radio signal transmitted from the base station (not shown) is received by an antenna 31 and is then input to a receiving circuit (RX) 33 through an antenna duplexer (DUP) 32 . The receiving circuit 33 mixes the received radio signal with a local oscillation signal output from a frequency synthesizer (SYN) 34 , and frequency-converts (down-converts) the radio signal into an intermediate frequency signal. Then, the receiving circuit 33 quadrature-demodulates the down-converted intermediate frequency signal and output a received baseband signal. The frequency of the local oscillation signal generated by the frequency synthesizer 34 is indicated by a control signal SYC output from a controller 41 .
[0037] The received baseband signal from the receiving circuit 33 is input to a CDMA signal processor 36 . The CDMA signal processor 36 has a RAKE receiver (not shown). The RAKE receiver despreads a plurality of paths included in the received baseband signal by using spread codes (that is, the same spread signal as a spread signal of a spread received signal). The signals of the despread paths are subject coherent Rake combination after their phases are adjusted. A sequence of data after Rake combination is subject to deinterleaving and channel decoding (error correction decoding), and binary data determination is then performed. In this way, received packet data having a predetermined transmission format is obtained. Received packet data is input to a compression/expansion processor 37 .
[0038] The compression/expansion processor 37 is formed by a Digital Signal Processor (DSP). The compression/expansion processor 37 demultiplexes received packet data output from the CDMA signal processor 36 into media data by a multiplexer/demultiplexer (not shown), and decodes the demultiplexed media data. For example, in a voice call mode, audio data corresponding to a voice included in received packet data is decoded by a speech codec. Like a video phone mode, if motion image data is included in received packet data, motion image data is decoded by a video codec. If received packet data is downloaded contents, the downloaded contents is expanded and then output to the controller 41 .
[0039] A digital audio signal obtained by decoding is supplied to a PCM codec 38 . The PCM codec 38 PCM-decodes the digital audio signal output from the compression/expansion processor 37 , and outputs an analog audio data signal after being PCM decoded to an incoming speech amplifier 39 . The analog audio signal is amplified by the incoming speech amplifier 39 and then output by the receiver 18 .
[0040] A digital motion image data decoded in the video codec by the compression/expansion processor 37 is input to the controller 41 . The controller 41 controls the main display 17 to display a motion image based on the digital motion image signal output from the compression/expansion processor 37 through a video RAM (for example, VRAM) (not shown). The controller 41 may control the main display 17 to display motion image data captured by the CCD camera 20 through the video RAM (not shown), as well as received motion image data.
[0041] When received packet data is data of an email, the compression/expansion processor 37 supplies the email to the controller 41 . The controller 41 stores the email from the compression/expansion processor 37 in a storage unit 42 . Then, according to the operation of the operating keys 14 serving as an input unit by the user, the controller 41 reads out the email stored in the storage unit 42 , and causes the main display 17 to display the read email.
[0042] Meanwhile, in the voice call mode, a speech signal (analog audio signal) of a speaker (user) input to the microphone 15 is amplified to an appropriate level by an outgoing speech amplifier 40 , and is then subject to PCM coding by the PCM codec 38 . A digital audio signal after PCM coding is input to the compression/expansion processor 37 . A motion image signal output from the CCD camera 20 is digitized by the controller 41 and is then input to the compression/expansion processor 37 . An email created by the controller 41 in the form of text data is also input to the compression/expansion processor 37 .
[0043] The compression/expansion processor 37 compresses and encodes the digital audio signal output from the PCM codec 38 to a signal of a format according to a predetermined transmission data rate. Accordingly, audio data is generated. In addition, the compression/expansion processor 37 compresses and encodes the digital motion image signal output from the controller 41 to generate motion image data. Then, the compression/expansion processor 37 multiplexes and packetizes audio data or motion image data by the multiplexer/demultiplexer (not shown) in accordance with a predetermined transmission format, and outputs transmission packet data after being packetized to the CDMA signal processor 36 . When an email is output from the controller 41 , the compression/expansion processor 37 also multiplexes the email to transmission packet data.
[0044] The CDMA signal processor 36 performs a spread spectrum processing on transmission packet data output from the compression/expansion processor 37 by using spread codes assigned to a transmission channel, and outputs an output signal after the spread spectrum processing to a transmitting circuit (TX) 35 . The transmitting circuit 35 modulates the signal after the spread spectrum processing by using a digital modulation scheme, such as a Quadrature Phase Shift Keying (QPSK) scheme. The transmitting circuit 35 mixes a transmission signal after digital modulation with the local oscillation signal generated from the frequency synthesizer 34 , and frequency-converts (up-converts) the transmission signal into a radio signal. Next, the transmitting circuit 35 high-frequency-amplifies the up-converted radio signal to a transmission power level designated by the controller 41 . The high-frequency-amplified radio signal is supplied to the antenna 31 through the antenna duplexer 32 , and is then transmitted from the antenna 31 to the base station (not shown).
[0045] The mobile phone 1 also has an external memory interface 45 . The external memory interface 45 has a slot into which a memory card 46 is detachably inserted. The memory card 46 is a kind of a flash memory card, such as a NAND flash memory card or a NOR flash memory card. In the memory card 46 , various kinds of data, such as image, sound, and music, can be rewritten and read out through a ten-pin terminal. The mobile phone 1 also has a clock circuit (timer) 47 that measures an accurate current time. A terrestrial digital one-segment broadcasting receiver 48 receives terrestrial digital one-segment broadcasting from a broadcasting station (not shown).
[0046] The controller 41 has a Central Processing Unit (CPU) a Read Only Memory (ROM), a Random Access Memory (RAM), and the like. The CPU performs various kinds of processing according to programs stored in the ROM or various application programs loaded on the ROM from the storage unit 42 , generates various control signals, and supplies the control signals to the individual parts so as to perform overall control of the mobile phone 1 . The RAM appropriately stores data required when the CPU performes various kinds of processing.
[0047] The storage unit 42 has, for example, an electrically rewrittable or erasable flash memory or a Hard Disc Drive (HDD). The storage unit 42 stores various application programs, which are performed by the CPU of the controller 41 , or various groups of data. The storage unit 42 also stores various kinds of contents (data regarding images for wallpaper) to be settable as a wallpaper.
[0048] A power supply circuit 44 generates a predetermined operation power supply voltage Vcc on the basis of the output of the battery 43 and outputs the operation power supply voltage Vcc to the individual circuits.
First Embodiment
[0049] According to the technology disclosed in JP-A-2003-223160, a display area for image information display can be changed to one of a plurality of prescribed display areas in accordance with temporal information. In this case, however, the display area of image information cannot but be changed to a prescribed display area. Of course, in the technology described in JP-A-2003-223160, a plurality of prescribed display areas may be appropriately changed in a pixel unit in accordance with the user's preference. In this case, it is time-consuming for the user to appropriately change the display area in a pixel unit in order to suppress occurrence burning in the screen, and it is not preferable in usability. In addition, the change of the display area for image information according to temporal information for every predetermined time results to an increase in power consumption.
[0050] The first embodiment has the following configuration. First, a display position at which image information (for example, image information regarding time to be superimposed on a wallpaper of a standby screen or image information regarding calendar) is appropriately shifted in a pixel unit (for example, in units of several pixels (dots)). Then, if a user operates the operating keys 14 to input an instruction to change the display position of the image information, the set display position of the image information is shifted in a pixel unit (for example, in units of several pixels (dots) ) according to a change processing of the display position of the image information. Therefore, it is possible to suitably suppress occurrence of burning in a display device. Hereinafter, an image information display position change processing using this method will be described.
[0051] The image information display position change processing in the mobile phone 1 of FIG. 3 will be described with reference to a flowchart of FIG. 4 . If the user operates the operating keys 14 to input an instruction to start the image information display position change processing, the image information display position change processing starts. Specifically, as a requisite for the image information display position change processing, the controller 41 of the mobile phone 1 has a wallpaper setting function for setting a desired wallpaper on the standby screen. If an instruction to set a wallpaper on the standby screen is received from the user, the controller 41 sets a wallpaper according to the user's preference onto the standby screen on a wallpaper setting screen. At this time, when receiving an instruction to change a display position of image information to be superimposed on the wallpaper of the standby screen on the wallpaper setting screen (an instruction to start the image information display position change processing), the controller 41 controls the main display 17 to display an image information display position change screen, which is a display screen for changing the display position of the image information, and starts the image information display position change processing.
[0052] The main display 17 is formed by an organic EL device and has a plurality of pixels (for example, 240×400 pixels) arranged in a matrix shape. The display position on the display screen of the main display 17 is expressed by two coordinate axes (X axis and Y axis) according to the arrangement of the plurality of pixels. On the display screen of the main display 17 , as a display position for displaying image information, one or more initial display positions (for example, display positions of upper left, upper right, center, lower left, and lower right sides expressed by display positions A 0 to E 0 of FIG. 5 ) are provided in advance. The image information is displayed at one from among the one or more initial display positions so as to be superposed on the wallpaper on the standby screen.
[0053] Thereafter, if the image information display position change processing is performed, a display position at which image information is currently displayed is changed to another display position from among a plurality of prescribed display positions (for example, initial display positions A 0 to E 0 of FIG. 5 ) on the display screen. At this time, each time the image information display position change processing described below is performed, a display position at which image information is to be displayed is sequentially shifted in unit of a predetermined number of pixels according to the change in the image information display position. That is, the image information is first displayed at one initial display position (initial display positions A 0 to E 0 FIG. 5 ) previously set on the display screen, and if the image information display position change processing is performed once, the display position at which the image information is to be displayed is shifted in units of a predetermined number of pixels. Thereafter, each time the image information display position change processing is performed, the display position at which the image information is to be displayed is sequentially shifted from the current display position in units of a predetermined number of pixels according to the change in the image information display position.
[0054] Although in the embodiment of the invention, an example where five initial display positions (initial display positions A 0 to E 0 of FIG. 5 ) are provided in advance on the display screen as the initial display position, this is not intended to limit the invention. For example, four or less initial display positions or six or more initial display positions may be provided in advance.
[0055] In displaying the image information, a two-dimensional area (display area) for displaying the image information is required. In general, when the display area of the image information has a rectangular shape, the length of each side is fixed to a known value. Therefore, the display position of the image information, such as the initial display positions A 0 to E 0 of FIG. 5 , is expressed by the coordinate of a center position of at least one point included in the display area of the image information by using the coordinates of two coordinate axes (X axis and Y axis) according to the arrangement of the plurality of pixels.
[0056] The initial display position Ac of FIG. 5 is a display position which is expressed by the coordinate (50, 320) of the center position of the display area, and the display position D 0 of FIG. 5 is a display position which is expressed by the coordinate (50, 90) of the center position of the display area. What is necessary is that the display position of the image information can be clearly represented. The display position of the image information may be expressed by coordinates other than the center position. For example, when the display area of the image information has a rectangular shape, the display position of the image information may be expressed by the coordinate of each vertex. The display area of the image information may have a shape (for example, a trapezoidal shape, a rhomboidal shape, a circular shape, or an elliptical shape) other than the rectangular shape.
[0057] In Step S 1 , the controller 41 determines whether or not the user operates the operating keys 14 to input an instruction to change the display position of the image information (for example, image information regarding time to be superimposed on the wallpaper of the standby screen or image information regarding calendar) to be superimposed on the wallpaper of the standby screen (an instruction to start the image information display position change processing) on the wallpaper setting screen, and waits for until the instruction to start the image information display position change processing is received.
[0058] Specifically, if the user operates the operating keys 14 to select “change of image information display position” to be displayed on the wallpaper setting screen, the controller 41 determines that the instruction to start the image information display position change processing is received.
[0059] In Step S 1 , if the controller 41 determines that the instruction to start the image information display position change processing is received, in Step S 2 , the controller 41 reads out coordinate information of all the initial display positions (when the display position of the image information is expressed by the center position, information regarding the coordinate the center position of the image information), at which the image information is to be displayed, stored in the storage unit 42 . For example, coordinate information of the center positions of the initial display position A 0 to E 0 shown in FIG. 5 are read out from the storage unit 42 .
[0060] Simultaneously, the controller 41 reads out differential coordinate information of the image information (that is, differential coordinate information, which is used to shift the display position of the image information in a pixel unit (in units of several pixels (dots) ) stored in the storage unit 42 .
[0061] The differential coordinate information includes, for example, information regarding a differential coordinate (Δx, Δy), which is used to shift the display position of the image information in a pixel unit. For example, when the display position of the image information is expressed by the center position (and the length of each side), the differential coordinate is a differential coordinate (Δx, Δy), which is used to shift the center position of the image information in a pixel unit. When the user does not operate the operating keys 14 to input the instruction to start the image information display position change processing, and the display position of the image information stills unchanged, the differential coordinate (Δx, Δy) has an initial value (Δx 0 , Δy 0 ), specifically, (0, 0). Meanwhile, when the user does not operate the operating keys 14 to input the instruction to start the image information display position change processing, and the display position of the image information is changed once or more, the differential coordinate (Δx, Δy) is sequentially changed to (Δx 1 , Δy 1 ), (Δx 2 , Δy 2 ), and the like according to the number of times by a differential coordinate change processing shown in Step S 7 , and specifically, it is changed from (0, 0) to (1, −1), (2, −2), and the like according to the number of times.
[0062] In Step S 3 , the controller 41 calculates the coordinate of a next display position, at which the image information is to be displayed, on the basis of the coordinate information of all the initial display position (for example, initial display position A 0 to E 0 shown in FIG. 5 ), at which the image information is to be displayed, and the differential coordinate information, which is used to shift the display position in a pixel unit.
[0063] As shown in FIG. 5 , on the basis of the coordinate of the center position of each of the initial display positions A 0 to E 0 , and the differential coordinate (Δx, Δy), the coordinate of each of the display positions (display positions A 1 to E 1 or display positions A 2 to E 2 ) indicated by dotted lines of FIG. 5 is calculated. If it is assumed that the display position A 0 of FIG. 5 is a display position that is expressed by the coordinate (50, 320) of the center position, and the display position D 0 of FIG. 5 is a display position that is expressed by the coordinate (50, 90) of the center position, the next display position A 1 of the image information at the display position A 0 is expressed by the coordinate (50+Δx 1 , 320+Δy 1 ) of the center position, and the next display position D 1 of the image information at the display position D 0 is expressed by the coordinate (50+Δx 1 , 90+Δy 1 ) of the center position. More specifically, when (Δx 1 , Δy 1 ) is (1, −1), the coordinate of the center position of the next display position A 1 becomes (51, 319), and the coordinate of the center position of the next display position D 1 becomes (51, 89).
[0064] The next display position A 2 of the image information at the display position A 1 of FIG. 5 is expressed by the coordinate (50+Δx 2 , 320+Δy 2 ) of the center position, and the next display position D 2 of the image information at the display position D 1 is expressed by the coordinate (50+Δx 2 , 90+Δy 2 ) of the center position. More specifically, when (Δx 2 , Δy 2 ) is (2, −2), the coordinate of the center position of the next display position A 2 becomes (52, 318), and the coordinate of the center position of the next display position D 2 becomes (52, 88).
[0065] Next, in Step S 4 , the controller 41 controls the main display 17 to display an image information display position change screen for changing the display position of the image information. Under the control of the controller 41 , the main display 17 displays the image information display position change screen for changing the display position of the image information. In Step S 3 , the coordinates of the next display positions (display positions A 0 to E 0 , display positions A 1 to E 1 , or display positions A 2 to E 2 ) at which the image information is to be displayed. Then, by using the coordinates of the display positions (display positions A 0 to E 0 , display positions A 1 to E 1 , or display positions A 2 to E 2 ), the controller 41 displays the display positions of the image information on the image information display position change screen. Specifically, each time the image information display position change processing is performed, the display positions of the image information are sequentially shifted from the prescribed initial display positions (initial display positions A 0 to E 0 of FIG. 5 ) to the display positions A 1 to E 1 , and the display position A 2 to E 2 .
[0066] At this time, the user can operates the directional key from among the operating keys 14 on the image information display position change screen to focus one display position from among the display positions of FIG. 5 (display positions A 0 to E 0 , display positions A 1 to E 1 , or display positions A 2 to E 2 ). Thereafter, the user can press the enter key from among the operating keys 14 to change the display position, at which the image information is to be displayed, one from among the display positions of FIG. 5 (display positions A 0 to E 0 , display positions A 1 to E 1 , display positions A 2 to E 2 ).
[0067] In Step S 5 , the controller 41 determines whether or not the user operates the operating keys 14 to input a selection of one display position from among a plurality of display positions (in FIG. 5 , display positions A 0 to E 0 , display positions A 1 to E 1 , or display positions A 2 to E 2 ) displayed on the image information display position change screen, and waits for until it is determined that the selection of one display position from among a plurality of display positions displayed on the image information display position change screen. For example, it is assumed that, on the image information display position change screen, as a display position, the display position D 1 is selected from among the display positions A 1 to E 1 or the display position C 2 is selected from among the display positions A 2 to E 2 .
[0068] In Step S 5 , when the controller 41 determines that the selection of one display position from among a plurality of display positions on the image information display position change screen is accepted, in Step S 6 , the controller 41 controls the main display 17 to display the image information at the display position according to the selection. In other words, the controller 41 shifts the display position of the image information in a pixel unit on the basis of the display position selected from among the calculated next display positions according to the selection, and updates display of the image information.
[0069] Before the image information display position change processing, when the image information is currently displayed at the display position A 1 , if the image information display position change processing starts, in Steps S 2 to S 4 , the coordinate of the next display position at which the image information is to be displayed is calculated by using the differential coordinate information (Δx 2 , Δy 2 ) (the coordinates of the display positions A 2 to E 2 are calculated). Thereafter, if the display position C 2 is selected from among the display positions A 2 to E 2 on the image information display position change screen as the display position of the image information, the display position of the image information is changed from the display position A 1 before the image information display position change processing to the display position C 2 on the basis of the display position C 2 selected from among the next display positions (display positions A 2 to E 2 ), while shifting from the display position C 1 to the display position C 2 in a pixel unit, and then display of the image information is updated.
[0070] In Step S 7 , after display of the image information is updated, the controller 41 updates the differential coordinate information of the display position of the image information stored in the storage unit 42 and stores the updated differential coordinate information in the storage unit 42 . When the image information display position change processing starts, if the differential coordinate information (Δx, Δy) of the display position of the image information stored in the storage unit 42 is (Δx 0 , Δy 0 ), it is updated to (Δx 1 , Δy 1 ) by the differential coordinate information update processing shown in Step S 7 . In addition, when the processing starts, if the differential coordinate information (Δx, Δy) of the display position of the image information stored in the storage unit 42 is (Δx 1 , Δy 1 ), it is updated to (Δx 2 , Δy 2 ) by the differential coordinate information update processing shown in Step S 7 . More specifically, each time the change processing is performed, the differential coordinate (Δx, Δy) is updated to (Δx 1 , Δy 1 ), (Δx 2 , Δy 2 ), (Δx 3 , Δy 3 ), . . . . For example, each time the processing is performed, the differential coordinate (Δx, Δy) is updated from (0, 0) to (1, −1), (2, −2), (3, −3), . . . . Therefore, when a next image information display position change processing is performed, updated differential coordinate information of the display position of the image information stored in the storage unit 42 is used.
[0071] In Step S 8 , the controller 41 determines whether or not the user operates the operating keys 14 to input an instruction to end the image information display position change processing, and waits until it is determined that an instruction to start the image information display position change processing is received. In Step S 8 , if the controller 41 determines that the instruction to end the image information display position change processing is received, the image information display position change processing ends.
[0072] In the first embodiment of the invention, image information is displayed at one or a plurality of initial display positions set beforehand on a display screen, which has a plurality of pixels arranged in a matrix and is expressed by two coordinate axes in accordance with the arrangement of the plurality of pixels. Then, on the basis of coordinate information of the initial display positions, and differential coordinate information, which is used to shift the display position in a pixel unit, the coordinates of one or a plurality of next display positions, at which the image information is to be displayed by the main display 17 , according to one or the plurality of initial display positions are calculated. Therefore, on the basis of the calculated coordinates of one or the plurality of next display positions, control can be performed such that the image information is displayed at one next display position or one from among the plurality of next display positions.
[0073] Therefore, the next display position can be automatically calculated with high definition as occasion demands, and it is possible to avoid an inconsistency that the display area of the image information cannot but move to the prescribed number of display areas (for example, five display areas). Thus, it is possible improve usability, and it is possible to suitably suppress occurrence of burning in the display device. Furthermore, when the display position of the image information is changed to another display position, a next display position is calculated as occasion demands. As a result, it is possible to suppress an increase in power consumption when the display position is frequently shifted.
[0074] In the first embodiment of the invention, the coordinate of the next display position, at which the image information is to be displayed, is calculated by using the differential coordinate information, which is sequentially updated with reference to the initial display position (display positions A 0 to E 0 of FIG. 5 ) set beforehand on the display screen, but the invention is not limited thereto. The coordinate of the next display position of the image information calculated by the image information display position change processing may be stored, and the coordinate of the next display position at which the image information is to be displayed may be calculated by using the fixed differential coordinate information.
[0075] According to the types of image information, that is, image information regarding time to be superimposed on the wallpaper of the standby screen or image information regarding calendar, the differential coordinate, which is used to shift the display portion at which the image information is to be displayed, may vary so as to fit the size of the display area where the image information is to be displayed, and may be stored as coordinate information.
[0076] In the first embodiment of the invention, as shown in FIG. 5 , the prescribed five initial display positions are moved in parallel by using the same differential coordinate information, but the invention is not limited thereto. The display positions may be moved by using differential coordinates having different values in different directions (for example, different directions from among the vertical or horizontal directions, including oblique directions).
[0077] In the first embodiment of the invention, when the display position of the image information is changed to other display position, display of the image information is updated. Alternatively, when a predetermined time (for example, one week) has elapsed after the display position of the image information is shifted in a pixel unit according to the display position change processing, display of the image information may be updated. Of course, the predetermined time may be changed according to the user's preference.
[0078] As image information, in addition to image information regarding time to be superimposed on the wallpaper of the standby screen or image information regarding calendar, image information when news is displayed in a predetermined display area on the display screen, or image information, such as animation, may be used.
[0079] The invention may be applied to, in addition to the mobile phone 1 , other information processing apparatuses, such as a Personal Digital Assistant (PDA), a personal computer, a portable game machine, a portable music player, and a portable motion image player.
[0080] A series of processing described in the first embodiment of the invention may be performed by software or may be performed by hardware.
[0081] Although in the first embodiment of the invention, an example where the steps in the flowchart are performed in time series according to the described sequence has been described, the steps maybe not necessarily performed in time series. For example, the steps may be performed in parallel or individually.
Second Embodiment
[0082] The second embodiment, which is based on the aforementioned mobile phone 1 shown in FIGS. 1 to 3 , will be described. According to the technology disclosed in JP-A-2003-223160, a display area for image information display can be changed to another display area from among a plurality of display area in accordance with temporal information. However, when the same wallpaper is set on the standby screen for a long time, the screen may be burned.
[0083] In order to overcome this drawback, the second embodiment has the following configuration. First, an accumulation time from a time when a wallpaper is set on the standby screen is measured, and when a currently set wallpaper is not changed to another wallpaper until the accumulation time from the set time exceeds a predetermined time, the wallpaper is automatically changed to another wallpaper. Furthermore, the accumulation time is set and managed for each content used as a wallpaper on the standby screen (data regarding a wallpaper image), and contents whose accumulation time exceeds the predetermined time are deleted so as not to be set and registered as a wallpaper. Therefore, it is possible to suitably suppress occurrence of burning in the display device. Hereinafter, a wallpaper change processing using this method will be described.
[0084] The wallpaper change processing in the mobile phone 1 of FIG. 3 will be described with reference to a flowchart of FIG. 6 . As a prerequisite for the wallpaper change processing, a wallpaper from among a group of wallpapers based on a user's preference (for example, a desired wallpaper or a default wallpaper before the user sets a desired wallpaper) is set on the standby screen beforehand. When a wallpaper is set on the standby screen, the controller 41 starts to measure the accumulation time from the wallpaper set time by using the clock 47 serving as an accumulation time measurement timer. In measuring the accumulation time from the wallpaper set time, instead of the clock circuit 47 , the controller 41 may measure the accumulation time by using a software timer.
[0085] In Step S 101 , when the user operates the end/power key from among the operating keys 14 to start the mobile phone 1 , the controller 41 performs the following interrupt processing regularly. That is, by using the clock circuit 47 serving as an accumulation time measurement timer, for a currently set wallpaper, the controller 41 determines whether or not the accumulation time from the wallpaper set time exceeds a predetermined time (for example, 300 hours). Of course, the predetermined time (threshold value) may be set to hours (for example, 200 hours) other than 300 hours.
[0086] The lighting state of the main display 17 includes a state where the main display 17 is lighted bright (hereinafter, referred to as “full lighting state”), a state where the main display 17 is lighted darker than the full lighting state with light-emission brightness reduced, but characters or icons on the main display 17 can be recognizable (hereinafter, referred to as “partial state”), and a state where the main display 17 does not perform display (hereinafter, referred to as “light-out state”). Of the three states, in the full lighting state, S burning may be most likely to occur in the main display 17 . Therefore, the accumulation time from the wallpaper set time may be an accumulation time in a main lighting state, or may be simply an accumulation time after a wallpaper is set, regardless of the lighting state.
[0087] In Step S 101 , in regards to the currently set wallpaper, if the controller 41 determines that the accumulation time from the wallpaper set time has not exceeded the predetermined time, in Step S 102 , the controller 41 determines whether or not the user operates the operating keys 14 to input an instruction to change the currently set wallpaper to another paper (for example, a desired wallpaper based on a user's preference) even though the accumulation time from the wallpaper set time has not exceeded the predetermined time for the currently set wallpaper.
[0088] In Step S 102 , if the controller 41 determines that the instruction to change the currently set wallpaper to another wallpaper is received, in Step S 103 , the controller 41 reads out an accumulation time management table stored in the storage unit 42 , updates the accumulation time of the currently set wallpaper, and stores the updated accumulation time in the accumulation time management table.
[0089] FIG. 7A shows an example of the accumulation time management table stored in the storage unit 42 . Referring to FIG. 7A , as wallpapers to be set on the standby screen, a wallpaper A to a wallpaper D . . . are registered, and the accumulation time (h) are registered in association with the wallpapers. For example, in case of the “wallpaper A” of the first row, since it has not been set on the standby screen, the accumulation time from the wallpaper set time is registered “0 (h)”. In case of the “wallpaper B” of the second row, it has been set on the standby screen, and the accumulation time from the wallpaper set time is registered as “140 (h)”.
[0090] A wallpaper settable flag for indicating settability on the standby screen is also registered in association with each wallpaper. If the wallpaper settable flag is set in an “ON” state, it indicates that, since the accumulation time from the wallpaper set time has not exceeded the predetermined time, a corresponding wallpaper is settable on the standby screen as a wallpaper afterward. Meanwhile, if the wallpaper settable flag is set in an “OFF” state, it indicates that, since the accumulation time from the wallpaper set time has exceeded the predetermined time, a corresponding wallpaper is unsettable on the standby screen as a wallpaper afterward. The wallpaper settable flag is set in the “ON” state as a default. Furthermore, when the user registers a wallpaper image as a wallpaper, the wallpaper settable flag is set in the “ON” state.
[0091] When the currently set wallpaper is the “wallpaper B”, and the accumulation time has exceeded 50 hours until an instruction to change the currently set wallpaper to another wallpaper is received in Step S 102 , the accumulation time 50 hours is measured by the clock circuit 47 serving as the accumulation time measurement timer. In this case, the accumulation time of the wallpaper B (the accumulation time of the wallpaper B hitherto) registered in the accumulation time management table of FIG. 7A is “140 (h)”. Therefore, as shown in FIG. 7B , the accumulation time registered in association with the wallpaper B is updated to “190 (h)” and then stored.
[0092] In Step S 104 , the controller 41 controls the main display 17 to display only wallpapers, the accumulation time of which has not exceeded the predetermined time from the wallpaper set time (wallpapers, the wallpaper setting flag of which is set in the “ON” state), from among a group of wallpapers with reference to the wallpaper settable flag of the wallpapers managed in the accumulation time management table. The main display 17 displays only wallpapers, the accumulation time of which has not exceeded the predetermined time from the wallpaper set time, from among a group of wallpapers.
[0093] Specifically, referring to FIG. 7B , the wallpapers, the wallpaper settable flag is set in the “ON” state, are “wallpaper A”, “wallpaper A”, “wallpaper B”, “wallpaper D”, and“wallpaper E”. Therefore, as the wallpapers, the accumulation time of which has not exceeded the predetermined time from the wallpaper set time, the “wallpaper A”, the “wallpaper B”, the “wallpaper D”, and the “wallpaper E” are displayed on the main display 17 in the form of a list. As a result, the user can operate the directional key from among the operating keys 14 to select as a wallpaper on the standby screen one from among the “wallpaper A”, the “wallpaper B”, the “wallpaper D”, and the “wallpaper E”.
[0094] In Step S 105 , the controller 41 accepts a selection of one from among a group of wallpapers displayed on the main display 17 (that is, a group of wallpapers, the accumulation time of which has not exceeded the predetermined time from the wallpaper set time) according to the operation of the directional key from among the operating keys 14 by the user. In Step S 106 , when the selection of one wallpaper from among a group of wallpapers is accepted, the controller 41 sets a wallpaper corresponding to the selection as a wallpaper on the standby screen.
[0095] Referring to FIG. 7B , if the user operates the directional key from among the operating keys 14 and a selection of the “wallpaper A” from among the “wallpaper A”, the “wallpaper B”, the “wallpaper D”, and the “wallpaper E” displayed on the main display 17 is accepted, the “wallpaper A” is set as a wallpaper on the standby screen. The controller 41 stores set data about a wallpaper in the storage unit 42 . Set data about the wallpaper includes data regarding a wallpaper (for example, “wallpaper A”) set as a wallpaper on the standby screen.
[0096] In Step S 107 , the controller 41 controls the main display 17 to changes the currently displayed wallpaper to the wallpaper (for example, “wallpaper A”) set as a wallpaper on the standby screen. For example, when in Steps S 102 to S 106 the “wallpaper A” is set, and an instruction to change the currently displayed “wallpaper B” to the “wallpaper A” is input, the “wallpaper B” currently displayed on the main display 17 is changed to the “wallpaper A”.
[0097] In Step S 108 , the controller 41 resets the clock circuit 47 serving as an accumulation time measurement timer, and starts to measure the accumulation time of the wallpaper set as a wallpaper on the standby screen on the basis of the accumulation time managed by the accumulation time management table.
[0098] For example, when in Steps S 102 to S 106 , the “wallpaper A” is set, and an instruction to change the “wallpaper B” currently displayed to the “wallpaper A” is input, since the accumulation time of the “wallpaper A” managed by the accumulation time management table is “0 (h)”, the measurement of the accumulation time starts with the “0 (h)”. Meanwhile, when in Steps S 102 to S 106 , the “wallpaper E” is set, and an instruction to change the currently displayed “wallpaper B” to the “wallpaper E” is input, since the accumulation time of the “wallpaper A” managed by the accumulation time management table is “150 (h)”, the measurement of the accumulation time starts with “50 (h)”.
[0099] Thereafter, the processing returns to Step S 101 , and Step S 101 and later are repeatedly performed.
[0100] Meanwhile, in Step S 102 , if the controller 41 determines that no instruction to change the currently set wallpaper to another wallpaper is input, Steps S 103 to S 108 are skipped, and a change processing to another wallpaper is not performed.
[0101] In Step S 101 , if the controller 41 determines that, for the currently set wallpaper, the accumulation time has exceeded the predetermined time from the wallpaper set time, in Step S 109 , the controller 41 reads out the accumulation time management table stored in the storage unit 42 , updates the accumulation time of the currently set wallpaper, and stores the updated accumulation time in the accumulation time management table.
[0102] When the currently set wallpaper is the “wallpaper B”, and the accumulation time has exceeded the predetermined time (for example, 300 hours) from the wallpaper set time, the clock circuit 47 serving as an accumulation time measurement timer measures 300 hours. Then, as shown in FIG. 7C , the accumulation time registered in association with the wallpaper B is updated to “300 (h)” and then stored.
[0103] In Step S 110 , for the wallpaper, the accumulation time of which has exceeded the predetermined time from the wallpaper set time, the controller 41 sets the wallpaper settable flag managed by the accumulation time management table in the “OFF” state, and deletes (excludes) the corresponding wallpaper from a group of settable wallpapers.
[0104] When the currently set wallpaper is the “wallpaper B”, and the accumulation time has exceeded the predetermined time (for example, 300 hours) from the wallpaper set time, in order to suppress occurrence of burning in the main display 17 due to use of the same wallpaper, as shown in FIG. 7C , the wallpaper settable flag registered in association with the wallpaper B is set in the “OFF” state, and the corresponding wallpaper is deleted (excluded) from a group of settable wallpapers. For this reason, even though the user wants to set a wallpaper, which is once deleted from a group of wallpapers, as a wallpaper on the standby screen, it is impossible for the user to set the wallpaper as a wallpaper on the standby screen by the subsequent wallpaper change processing.
[0105] In Step S 111 , the controller 41 selects one from among wallpapers, the accumulation time of which has not exceeded the predetermined time from the wallpaper set time. In the example of FIG. 7C , since the wallpapers, the wallpaper settable flag of which is set in the “ON” state, are the “wallpaper A”, the “wallpaper D”, and the “wallpaper E”, one wallpaper (for example, “wallpaper D”) from among the “wallpaper A”, the “wallpaper D”, and the “wallpaper E” is automatically selected as a wallpaper on the standby screen.
[0106] Thereafter, the processing progresses to Step S 106 , and the wallpaper selected in Step S 106 is set as a wallpaper on the standby screen, and in Step S 107 , the currently set wallpaper is changed to the wallpaper set as a wallpaper on the standby screen. Then, in Step S 108 , the clock circuit 47 serving as the accumulation time measurement timer is reset, and the measurement starts based on the accumulation time of the wallpaper managed by the accumulation time management table.
[0107] In the second embodiment of the invention, a wallpaper is set on the standby screen, and by using an accumulation time measurement timer, which measures the accumulation time from the wallpaper set time for the set wallpaper, it is determined whether or not the accumulation time of the set wallpaper has exceeded the predetermined time. Furthermore, the accumulation time of the wallpaper measured by the accumulation time measurement timer is managed by the accumulation time management table in association with the wallpaper. If it is determined that the accumulation time of the wallpaper has exceeded the predetermined time, one wallpaper is selected from among wallpapers, the accumulation time of which has not exceeded the accumulation time from the wallpaper set time, selected from a group of wallpapers. In this way, it is possible to set the selected wallpaper as a wallpaper on the standby screen. Therefore, it is possible to prevent the same wallpaper from being displayed on the standby screen for a long time. Furthermore, with automatic wallpaper selection, it is possible to save user's trouble, and as a result, it is possible to suitably suppress occurrence burning in the main display 17 .
[0108] The predetermined time (threshold value) regarding the accumulation time of the wallpaper used in the embodiment of the invention may be appropriately changed in accordance with the user's preference. Further, according to the contents used as the wallpaper, since screen burning may easily occur, it is preferable to set the predetermined time (threshold value) to different values.
[0109] In the second embodiment of the invention, for a wallpaper, the accumulation time of which has exceeded the predetermined time from the wallpaper set time, the wallpaper settable flag is set in the “OFF” state, and the corresponding wallpaper is automatically deleted from a group of settable wallpapers on the standby screen. At this time, in terms of operationality or convenience, as shown in a flowchart of FIG. 8 , after a wallpaper is selected, popup display is performed to display and notify the user that the wallpaper is unusable afterward. For example, as shown in FIG. 8 , in Step S 131 (corresponding to Step S 111 ), if the controller 41 selects one wallpaper from among wallpapers, the accumulation time of which has not exceeded the predetermined time from the wallpaper set time, in Step S 132 , the controller 41 controls the main display 17 to display in a popup manner that for a wallpaper, the accumulation time of which has exceeded the predetermined time from the wallpaper set time, is unusable as a wallpaper afterward. Specifically, as shown in FIG. 7C , the wallpaper settable flag registered in association with the wallpaper B is set in the “OFF” state and then deleted (excluded) from a group of settable wallpapers. Therefore, a message purporting that “the wallpaper B has an accumulation time that exceeds a settable accumulation time and is unusable as a wallpaper.” is displayed on the main display 17 in a popup manner. Steps S 121 to S 131 in FIG. 8 are basically the same as Steps S 101 to S 111 in FIG. 6 , and thus redundant descriptions thereof will be omitted.
[0110] If the accumulation time managed by the accumulation time management table is within 10 hours (several hours) before the predetermined time (for example, 300 hours), popup display may be performed to notify that the wallpaper is unusable afterward, and the user may be requested to change the wallpaper to another wallpaper.
[0111] Although in the second embodiment of the invention, a wallpaper displayed on the standby screen has been explicitly described, this is not intended to limit the invention. For example, the invention can be applied to an image other than a wallpaper. The invention can be applied to an image whose display size is smaller than a display size of the wallpaper, while the display size of the wallpaper is the same size as a size of the screen.
[0112] The invention maybe applied to, in addition to the mobile phone 1 , other information processing apparatuses, such as a Personal Digital Assistant (PDA), a personal computer, a portable game machine, a portable music player, and a portable motion image player.
[0113] A series of processing described in the second embodiment of the invention may be performed by software or may be performed by hardware.
[0114] Although in the second embodiment of the invention, an example where the steps in the flowchart are performed in time series according to the described sequence has been described, the steps may be not necessarily performed in time series. For example, the steps may be performed in parallel or individually.
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According to one aspect of the invention, there is provided an information processing apparatus including: a display configured to include a display screen and to display image information at a display position on the display screen, the display screen having a plurality of pixels arranged in a matrix, the display position represented by pixel-based coordinates; a calculation module configured to calculate coordinates of a next display position at which the image information is to be displayed next based on coordinate information of the display position and differential coordinate information, the coordinate information representing a position where the image information is to be displayed, the differential coordinate information representing a pixel-based distance with which the display position shifts,; and a display control module configured to control the display to display the image information at the next display position based on the coordinate thereof.
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This Application is the U.S. National Phase of International Application Number PCT/GB2011/052551 filed on Dec. 21, 2011, which claims priority to Great Britain Application No. 1104101.9 filed on Mar. 10, 2011.
BACKGROUND OF THE INVENTION
(1) Field of Invention
This invention relates to subsea risers used to transport well fluids from the seabed to a surface installation such as an FPSO vessel or a platform. The invention relates particularly to systems for restraining movement of such risers under the action of currents or excursion of an FPSO.
Hybrid riser systems have been known for many years. Such systems use riser pipes, possibly of lined and coated steel, that extend upwardly from the seabed to near the surface. Flexible jumper pipes extend from there to the surface to add compliancy that decouples the more rigid riser pipes from surface movement induced by waves and tides. The riser pipes experience less stress and fatigue as a result, especially at the vulnerable sag bend near their touchdown point on the seabed.
More specifically, a hybrid riser system comprises a subsea riser support extending from a seabed anchorage to an upper end held buoyantly in mid water, at a depth below the influence of likely wave action. A depth of 250 m is typical for this purpose but this may vary according to the sea conditions expected at a particular location.
The riser support may comprise a hybrid riser tower or ‘HRT’ pivotably attached to the anchorage and held in tension by buoyancy at its upper end, or a riser support buoy tethered to the anchorage under tension. A riser support buoy is sometimes referred to by the acronym ‘BSR’, derived from the Portuguese term ‘bóia de suporte de riser’. That acronym will be used to identify riser support buoys in the description that follows.
Riser pipes extend from the seabed to the upper end region of the riser support. In the case of an HRT, the riser pipes will typically extend along the HRT as an upright bundle of generally parallel pipes. In the case of a BSR, the riser pipes will typically hang freely from, and splay away from, the BSR as steel catenary risers or ‘SCRs’. SCRs are a non-limiting example: other types of pipe are possible for the riser pipes.
Jumper pipes hanging as catenaries extend from the upper end region of the riser support to an FPSO or other surface installation. The FPSO is moored at a location above the riser support and spaced or offset horizontally from the riser support.
When viewed from above so that the arcuate shape of the jumper pipes and the depth of the riser support beneath the surface is not apparent, there is a general flow direction extending from the upper end region of the riser support toward the FPSO. The flow direction will be used to explain the present invention in more detail and is illustrated in FIGS. 2 a , 3 a and 4 a of the accompanying drawings.
In the case of a BSR, when similarly viewed from above, the SCRs extend from the BSR in a direction generally opposed to the flow direction; optionally, the SCRs also diverge from each other moving away from the BSR.
Umbilicals and other pipes generally follow the paths of the riser pipes and jumper pipes to carry power, control data and other fluids.
In deep water, a surface installation such as an FPSO will usually have spread moorings. Spread moorings typically comprise four sets of mooring lines (each set being of say four to six mooring lines) with the sets radiating with angular spacing from the FPSO to anchors such as suction piles or torpedo piles embedded in the seabed. Such moorings can maintain the FPSO on location for several years at a fixed orientation or heading without ‘weathervaning’ rotation about a vertical axis. This minimal yaw movement means that there is no need for a turret structure or for swivel connections for fluids, power and control data. The connections are therefore advantageously simplified. Also, flexible riser pipes and umbilicals may simply be connected amidships along sides of the FPSO, which maximises the space available for those connections.
In a spread-moored arrangement, a riser system is typically accommodated between neighbouring sets of mooring lines of the FPSO. Space may be limited such that in extreme weather conditions, there is a potential for interference between the mooring lines of the FPSO and the riser supports and/or the riser pipes.
The potential for interference is greater still where a plurality of riser supports are combined with a single surface installation such as an FPSO, as more space is required for plural riser supports. Also, arrangements having a plurality of riser supports introduce the further risk of interference between neighbouring riser supports or between the riser pipes carried by those neighbouring riser supports.
It is desirable to stabilise riser supports against excessive movement in extreme conditions. The buoyancy that creates tension in a riser support is a stabilising factor; so too is the horizontal component of the force applied to the riser support by the jumper pipes. Also, where SCRs or other riser pipes hang from a BSR, the SCRs apply to a lesser extent a force to the BSR whose horizontal component is opposed to the horizontal component of the force applied to the BSR by the jumper pipes. This, too, helps to stabilise a BSR. However it may be desirable to apply other stabilising restoring forces to a riser support.
(2) Description of Related Art
GB 2346188, U.S. Pat. No. 6,595,725 and US 2006/0056918 disclose riser arrangements in which a plurality of riser supports are shared by a single surface installation. GB 2346188 discloses a row of HRTs whereas U.S. Pat. No. 6,595,725 and US 2006/0056918 each disclose two BSRs. All of those documents propose additional means for stabilising the riser supports but they work in very different ways—none of which are helpful for the purposes of the present invention.
GB 2346188 discloses interconnecting tethers between the riser towers near their upper ends. This interconnection is intended to limit differential movement between the neighbouring riser towers but it also allows—and indeed encourages—the whole row of riser towers to move together. So, there is nothing to prevent the row of towers colliding with any adjacent spread moorings. Also, the interconnecting tethers in GB 2346188 hang as shallow catenaries and so have negative buoyancy, which means that the riser towers will be pulled together by the tension in the tethers due to their weight. In practice, this will cause the riser towers to lean toward each other, thus increasing the risk of collision between neighbouring towers in extreme conditions. This is a particular risk with the towers at the ends of the row.
U.S. Pat. No. 6,595,725 discloses two riser supports but they are not grouped together: instead, one riser support is disposed to each side of a production facility floating above. The jumper pipes and riser pipes apply opposed stabilising forces to each riser support in directions parallel to the flow direction. Additionally, guy lines extend to the seabed from each riser support to prevent lateral movement due to water current. There is no practical risk of collision between the riser supports and there is space to avoid collision between the riser supports and spread moorings of the production facility. However, the arrangement would not be suitable for accommodating a group of two or more aligned riser supports between neighbouring sets of mooring lines of a spread-moored FPSO.
US 2006/0056918 discloses a weighted line between two riser supports but the weighted line only applies restoring forces parallel to the flow direction. As in U.S. Pat. No. 6,595,725 above, the riser supports are not grouped to one side of a surface installation floating above: instead, one riser support is disposed to each side of the surface installation. Again, therefore, there is no risk of collision between the riser supports and there would be space to avoid collision between the riser supports and spread moorings, if used.
If the riser supports of U.S. Pat. No. 6,595,725 or US 2006/0056918 were grouped to one side of the surface installation (not that there is any motivation or suggestion in those documents to adapt those proposals in that way), there would be a risk of collision between the riser supports and between the riser supports and spread moorings, if used.
It is against this background that the present invention has been devised.
BRIEF SUMMARY OF THE INVENTION
The invention resides in a seabed-to-surface riser system of the type comprising: a group of two or more subsea riser supports each extending upwardly from a seabed anchorage to a buoyant upper end region located beneath the surface and each supporting at least one riser pipe extending from the seabed to the upper end region; and at least one jumper pipe extending from the upper end region of each riser support to a surface installation at a location above the riser support and spaced horizontally from the riser support in a flow direction.
Expressed broadly, the invention contemplates that the group of riser supports is disposed to one side of the surface installation; that at least outermost riser supports of the group lie on an axis transverse to the flow direction; that a plurality of laterally-extending flexible lines are attached to each of those outermost riser supports, those lines applying mutually-opposed stabilising forces to each outermost riser support in directions transverse to the flow direction; and that at least one of the laterally-extending flexible lines is a mooring line that extends from an outermost riser support of the group to the seabed.
By virtue of the invention, movement of the group of riser supports is effectively restrained. This enables better use of space without risking interference with other subsea elements such as FPSO moorings.
Each riser support extends substantially vertically from its seabed anchorage with an angle from vertical from 0 to 15 deg and preferably from 0 to 10 degree. This deviation from vertical is due to horizontal current and forces applied on the riser support by FPSO.
In some embodiments, a riser support of the group is preferably connected to one or more neighbouring riser supports of the group by at least one line extending transversely with respect to the flow direction. This helps to control movement of riser supports with respect to each other, and enhances control of movement in the system as a whole.
To restrain the riser supports in orthogonal directions, at least two lines may splay laterally from at least one side of a riser support of the group. For example, at least two lines may splay laterally from one side of a riser support of the group and at least one line may extend laterally from an opposite side of that riser support to apply opposed stabilising forces to that riser support.
In an embodiment of the invention to be described, at least one riser support of the group is coupled by a line to the surface installation. Preferably that line extends laterally from the riser support to impart a stabilising force to the riser support transverse to the flow direction. The riser support may, for example, be braced between a mooring line and a line coupling the riser support to the surface installation, those lines applying stabilising forces to the riser support in opposite and substantially aligned directions.
More preferably, at least two riser supports of the group are coupled by respective lines to the surface installation, which lines initially converge as they extend from the riser supports to the surface installation. In a compact variant of this arrangement, the lines that couple the riser supports to the surface installation cross over between the riser supports and the surface installation and then diverge from a cross-over point to attachment points on the surface installation spaced in a direction transverse to the flow direction. In that case, one of those lines is suitably supported by a subsea buoy around the cross-over point to raise it above the other such line that it crosses.
The invention has particular advantages where the surface installation has spread moorings, as the invention enables a group of riser supports to be disposed between neighbouring sets of mooring lines of the spread moorings. At least one of the laterally-extending lines that is a mooring line is preferably supported by a subsea buoy to raise that mooring line above spread mooring elements of the surface installation. This avoids possible interference between the riser system and the spread moorings.
The riser supports may comprise HRTs or BSRs but the invention also has particular advantages when applied to BSRs. Here, a riser support comprises a subsea buoy tethered to a foundation, and the riser pipes preferably extend downwardly from the buoy and in a direction opposed to the flow direction. It is then possible for the buoy to be subject to stabilising forces in the flow direction from the jumper pipes, opposite to the flow direction from the riser pipes, and transverse to the flow direction from opposed laterally-extending lines.
Two or more laterally-extending lines may be attached to a subsea buoy at mutually-spaced locations on the buoy to resist yaw movement of the buoy. Those lines preferably extend from one side of the buoy.
Riser supports of the group are preferably substantially aligned on an axis transverse to or orthogonal to the flow direction. Where the surface installation is an FPSO, that axis is suitably substantially parallel to a central longitudinal axis of the FPSO. The laterally-extending lines may be disposed substantially in a plane containing that axis.
In the embodiments of the invention to be described, the group of riser supports comprises at least two outer riser supports moored to the seabed or to the surface installation by laterally-extending lines and at least one inner riser support between the outer riser supports. The inner riser support may be coupled to at least one of the outer riser supports.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more readily understood, reference will now be made by way of example to the accompanying drawings, in which:
FIG. 1 is a perspective view of a riser installation to which restraint systems of the invention may be applied, the installation comprising two BSRs used with a single spread-moored FPSO;
FIG. 2 a is a schematic plan view of a riser installation comprising three HRTs and having a restraint system in accordance with the invention;
FIG. 2 b is a schematic side view of the riser installation of FIG. 2 a;
FIG. 3 a is a schematic plan view of a riser installation comprising three BSRs and having an alternative restraint system in accordance with the invention;
FIG. 3 b is a schematic side view of the riser installation of FIG. 3 a;
FIG. 4 a is a schematic plan view of a riser installation comprising three BSRs and having a further alternative restraint system in accordance with the invention; and
FIG. 4 b is a schematic side view of the riser installation of FIG. 4 a.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 of the drawings does not show the restraint systems of the invention but instead explains their context. In contrast, the remaining Figures are schematic and show embodiments of the invention. Like numerals are used for like parts where appropriate.
Referring firstly then to FIG. 1 to appreciate the background of the invention, a riser installation 10 comprises two riser supports 12 each comprising a BSR 14 , a seabed foundation 16 and a tether arrangement 18 extending between the foundation 16 and the BSR 14 . Each tether arrangement 18 comprises four tethers in this example, maintained under tension by the buoyancy of the BSR 14 .
Each BSR 14 supports a group of riser pipes 20 in the form of SCRs that each extend from respective PLETs 22 across the seabed, through a sag bend 24 and from there up to the BSR 14 . The riser pipes 20 splay apart moving downwardly and away from the BSR and each group of riser pipes 20 fans out across the seabed to the PLETs 22 .
Each riser pipe 20 communicates with a respective jumper pipe 26 that hangs as a catenary between the BSR 14 and an FPSO 28 . The FPSO 28 is moored with its hull extending parallel to an axis containing both BSRs 14 , whereby the jumper pipes 26 connect amidships to one side of the FPSO 28 .
As noted previously, umbilicals and other pipes 30 generally follow the paths of the riser pipes 20 and jumper pipes 26 . These pipes 30 can be distinguished from the riser pipes 20 in FIG. 1 as they do not terminate in PLETs 22 , and as they have a smaller bend radius at the sag bend 24 . Umbilicals and other pipes 30 are omitted from the remaining Figures for clarity.
The FPSO 28 shown in FIG. 1 is spread-moored with four sets 32 of six mooring lines 34 . Two of those sets 32 of mooring lines 34 —one attached near each end of the FPSO 28 —are shown in FIG. 1 and indeed in all of the Figures except FIG. 2 a , which shows all four sets 32 around the FPSO 28 .
It will be clear from FIG. 1 that the riser installation 10 is accommodated closely between these neighbouring sets 32 of mooring lines 34 . It is desirable to space the riser pipes 20 and other pipes 30 as far apart as possible and so to maximise usage of the space between the neighbouring sets 32 of mooring lines 34 . Thus, the outermost PLETs 22 are close to the seabed anchors of the innermost mooring lines 34 .
The restraint systems of the invention allow the riser pipes 20 , PLETs 22 and so on to be arranged to best effect, with maximum possible spacing within the confines of the spread moorings without risking interference between the mooring lines 34 and the riser supports 12 or the riser pipes 20 .
Moving on now to FIGS. 2 a and 2 b , these show a first embodiment of the invention applied to a group of three HRTs 36 extending upwardly in a row from respective seabed anchorages or foundations 38 to a mid-water position. The HRTs 36 are spaced apart along a common axis that lies generally parallel to the longitudinal centreline of the FPSO 28 .
For ease of illustration, each HRT 36 is shown with just three riser pipes and jumper pipes 26 extending as a catenary to the FPSO 28 . The jumper pipes 26 of each HRT 36 may splay apart slightly, as shown, from the HRT 36 to the FPSO 28 but the jumper pipes 26 of the HRTs 36 in general may converge slightly from the HRTs 36 to the FPSO 28 as shown.
Arrow F in FIG. 2 a shows the aforementioned general flow direction extending from the HRTs 36 toward the FPSO 28 . This may be helpful for understanding and defining the invention. In this example, the general flow direction is orthogonal to the axis of the HRTs 36 and it will usually be at least transverse to, or intersect, the axis of the HRTs 36 .
In this embodiment of the invention, neighbouring HRTs 36 are optionally coupled together by laterally-extending lines 40 that hang as catenaries in a plane containing the axis of the HRTs 36 . The innermost, central HRT 36 is coupled to two such lines 40 , one to each side, extending from the central HRT 36 to respective ones of the outermost HRTs 36 .
In turn, further laterally-extending lines 42 extend outwardly and generally downwardly from the outermost HRTs 36 . The lines 42 are moored to the seabed in this embodiment. Again, the lines 42 hang in a plane containing the axis of the HRTs 36 . The lines 40 , 42 thus apply mutually-opposed stabilising or restoring forces to the HRTs 36 , in directions transverse to (in this case orthogonal to) the flow direction shown by arrow F.
Optionally as shown, each line 42 is supported at an intermediate location by a subsea buoy 44 . The buoy 44 reduces stress in the line 42 and also, elegantly, ensures ample clearance where the line 42 crosses over an adjacent set 32 of mooring lines 34 attached to the FPSO 28 . Arrows C in FIG. 2 b show this clearance schematically.
The second embodiment of the invention in FIGS. 3 a and 3 b shows how the restraint system of the invention may also be applied to a group of BSRs 14 , in this case three BSRs 14 in a row. The BSRs 14 are spaced apart along a common axis that lies generally parallel to the longitudinal centreline of the FPSO 28 . They are suspended in a mid-water position by tether arrangements 18 attached to respective seabed foundations 16 in the manner shown in FIG. 1 .
For ease of illustration, each BSR 14 is shown with just one riser pipe 20 extending from the seabed to the BSR 14 and just one jumper pipe 26 extending from the BSR 14 to the FPSO 28 . In practical applications, there will generally be several such pipes as FIG. 1 makes clear.
Other features of this second embodiment are similar to those of the first embodiment shown in FIGS. 2 a and 2 b . Arrow F in FIG. 3 a shows the aforementioned general flow direction that, in this case, extends from the BSRs 14 toward the FPSO 28 . Again, the general flow direction is orthogonal to the axis of the BSRs 14 in this example and it will usually be at least transverse to, or intersect, the axis of the BSRs 14 .
Again, optionally, neighbouring BSRs 14 are coupled together by laterally-extending lines 40 that hang as catenaries in a plane containing the axis of the BSRs 14 . The innermost, central BSR 14 is therefore coupled to two such lines 40 , one to each side, extending from the central BSR 14 to respective ones of the outermost BSRs 14 .
Again, further laterally-extending lines 42 extend outwardly and generally downwardly from the outermost BSRs 14 in a plane containing the axis of the BSRs 14 , to be moored to the seabed. And again, each line 42 is supported at an intermediate location by a subsea buoy 44 that ensures clearance where the line 42 crosses over an adjacent set 32 of mooring lines 34 attached to the FPSO 28 .
In a similar manner to the first embodiment, the lines 40 , 42 thus apply mutually-opposed stabilising or restoring forces to the BSRs 14 , in directions transverse to (in this case orthogonal to) the flow direction shown by arrow F.
FIG. 3 a shows, in dashed lines, a variant of this second embodiment in which the lines 42 ′ extending outwardly from the outermost BSRs 36 depart from the plane containing the axis of the BSRs 14 . Indeed, there may be two such lines 42 ′ on each of the outermost BSRs 14 , diverging from the plane containing the axis of the BSRs 14 . This provides opposed restoring forces acting parallel to the flow direction of arrow F, to restrain the BSRs 14 against inward or outward movement with respect to the FPSO 28 . Also, if the lines 42 ′ are attached to different points on the BSRs 14 such as different corners as shown, they will resist yaw of the BSRs 14 . Again, subsea buoys 44 ′ ensure clearance where the lines 42 ′ cross over adjacent sets 32 of mooring lines 34 attached to the FPSO 28 .
Referring finally to the third embodiment shown in FIGS. 4 a and 4 b of the drawings, here again there are three BSRs 14 in a row. Again, the BSRs 14 are spaced apart along a common axis that lies generally parallel to the longitudinal centreline of the FPSO 28 . The BSRs 14 are suspended in a mid-water position by tether arrangements 18 attached to respective seabed foundations in the manner shown in FIG. 1 .
For ease of illustration, each BSR 14 is again shown with just one riser pipe 20 extending from the seabed to the BSR 14 and just one jumper pipe 26 extending from the BSR 14 to the FPSO 28 .
Again, arrow F in FIG. 4 a shows the aforementioned general flow direction extending from the BSRs 14 toward the FPSO 28 . That flow direction is orthogonal to the axis of the BSRs 14 in this illustration and it will usually be at least transverse to, or will intersect, the axis of the BSRs 14 .
In this third embodiment, the outermost BSRs 14 are braced respectively by laterally-extending lines 46 , 46 ′ that are angled to connect to the FPSO 28 and by opposed laterally-extending lines 48 that extend outwardly and generally downwardly to be moored to the seabed. The lines 48 are substantially aligned with the associated lines 46 , 46 ′ in plan view as shown in FIG. 4 a.
To impart a restoring force component in a direction orthogonal to the flow direction of arrow F, the lines 46 , 46 ′ extend at angles that lie between the flow direction and the common axis of the BSRs 14 , approximately in the range 30° to 60° and preferably in the range 40° to 50° with respect to the flow direction as shown.
The plan view of FIG. 4 a also shows that, for compactness, the lines 46 , 46 ′ cross over to connect to attachment points 50 spaced along the FPSO 28 at ends opposed to the BSRs 14 from which the lines 46 , 46 ′ originate. As FIG. 4 b makes clear, the line 46 ′ is in a shallow catenary form and the line 46 is in a lazy-W form suspended near its mid-point by a subsea buoy 52 to provide clearance for the line 46 ′ extending beneath.
Like the first and second embodiments, the lines 46 , 46 ′, 48 thus apply mutually-opposed stabilising or restoring forces to the outermost BSRs 14 , with components in directions orthogonal to and also parallel with the flow direction shown by arrow F.
As on the lines 42 , 42 ′ of the preceding embodiments, optional subsea buoys 44 ensure clearance where the lines 48 cross over adjacent sets 32 of mooring lines 34 attached to the FPSO 28 .
In the third embodiment, neighbouring BSRs 14 are not coupled together by the laterally-extending lines 40 of the preceding embodiments. The innermost, central BSR 14 is therefore restrained only by the restoring forces applied by the riser pipes 20 and jumper pipes 26 and by the buoyancy of that BSR 14 . However such lines 40 are optional and may be added to the third embodiment if it is desired to couple the central BSR 14 to each of the outermost BSRs 14 .
The lines 42 , 42 ′ and 48 in the embodiments described above could, for example, be made of fibre rope to minimise their weight.
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A seabed-to-surface riser system is disclosed. The seabed-to-surface riser system has a group of subsea riser supports that each support riser pipes extending from the seabed to mid-water. Jumper pipes extend from there to a floating production, storage and offloading (FPSO) offset horizontally from the riser support in a flow direction. The group of riser supports is disposed to one side of the surface installation. Laterally-extending lines are attached to at least the outermost riser supports of the group. Those lines apply mutually-opposed stabilizing forces to those outermost riser supports in directions transverse to the flow direction.
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FIELD OF THE INVENTION
[0001] The present invention is directed to the formation of a solid, dispersible flame retardant and/or smoke suppressant powder, by depositing solid flame retardant particles, via electrostatic and packing interactions, onto emulsified droplets of a melted wax, melted polymer, or organic solid carrier, or onto droplets of an organic liquid carrier. The invention also is directed to the use of such particles as flame retardants in a thermoplastic or thermosetting polymer composition. Additionally, the invention is directed to the use of such particles as flame retardants in thermoplastic or thermosetting polymer compositions and as coatings, such as textile backing coatings.
BACKGROUND OF THE INVENTION
[0002] The ability of various solids to act as flame retardants is well known to those skilled in the art. Examples of such flame retardant solids include hydrated salts, organic phosphates, metal borates, polyamides, solid halogenated flame retardants with a melting point greater than 100° C., molybdenum compounds, ferrocenes, antimony compounds, zinc compounds, and bismuth compounds. Such solids impart flame retardant properties by various mechanisms, including the following:
[0003] a) Release of Water and/or Carbon Dioxide: Hydrated salts (e.g., magnesium sulfate pentahydrate, aluminum trihydrate, magnesium hydroxide, and the like) decompose at high temperatures to endothermically release water and/or carbon dioxide to quench a fire.
[0004] b) Char Formation: When exposed to fire and/or high temperatures, char formers (e.g., organic phosphates, zinc compounds, nitrogen compounds, silicon compounds, and metal borates) form char barriers which insulate the combustible material from the fire, preventing the material from reaching combustion temperature.
[0005] c) Free Radical/Oxygen Deprivation: Halogen compounds, alone or in combination with antimony, will prevent combustion. The primary mechanism is believed to be the formation of a dense gas layer which inhibits oxygen from reaching the flame, thereby quenching the fire. There is also evidence that halide compounds, alone or in combination with antimony, may scavenge free radicals in the flame, thereby stopping the combustion reaction.
[0006] All of the above listed flame retardant solids are used commercially to provide flame retardation in a variety of commercial materials, such as plastics, carpets, fabrics, paints, coatings, adhesives, and the like. Unfortunately, the use of such solids in a flame-retarding effective amount is often limited, due to the imparting of other undesirable properties to the materials by the solid flame retardant at a relatively low loading level. Such properties include a loss of flexibility, loss of impact strength, addition of unwanted coloration, and loss of light transmission.
[0007] In thermoplastic polymer compositions, a combination of antimony trioxide, such as Laurel Fire Shield H (Oxy Corp.) or Timonox Red Star (Great Lakes Sales (UK) Ltd.), and a halide (e.g., octabromodiphenyl-oxide, decabromodiphenyloxide, ethylene bis-tetrabromophthalimide, or decabromodiphenylethane) is the preferred commercial combination for imparting flame retardant properties to the polymer. Unfortunately, such antimony trioxide/halide combinations can cause the thermoplastic polymer compositions to suffer from one or more of the undesirable properties described above. In addition, if the particle size of the flame retardant solid is large relative to the particle size of the polymer composition, inadequate heterogeneous mixing of the flame retardant and the polymer and/or aggregation of flame retardant particles in the polymer may occur, causing a further reduction in the flame retardancy, flexibility, and strength of the finished polymer articles.
[0008] It is well known in the art that many of the undesirable properties described above can be substantially reduced or eliminated by ensuring that the particle size of the flame retardant solid used is below 0.1 micron. Such particle sizes can be achieved through wet media milling of the flame retardant, using water, an organic liquid, or a meltable solid dispersion. For example, U.S. Pat. No. 5,948,323 issued to McLaughlin et al., and hereby incorporated by reference, describe stable dispersions of wet media milled colloidal flame retardant solid particles, having a size of about 1 to 1,000 nanometers, with an average size from 1 - 100 nanometers, in fluids such as water, organic liquids, or meltable solids, and methods of making them. However, the high fluid content of such wet media milled dispersions (e.g, 40-95% by weight fluid vehicle and 5-60% by weight solids), can limit the use of such dispersions as flame retardants in solid thermoplastic polymer compositions, as well as other solids. The high fluid levels present can result in defects, such as the trapping of liquid or gas particles in the thermoplastic polymer composition during processing, or inadequate dispersion of the flame retardant within the thermoplastic polymer composition due to fluid which remains associated with the flame retardant particles.
[0009] While such fluid dispersions can be dried directly using various methods known to those skilled in the art, such techniques remain limited by the tendency of the flame retardant, upon drying, to associate in hard agglomerates or clumps of material. Such agglomerates are believed to be stabilized by capillary pressure between solid particles around the exterior of individual solid particles of flame retardant, even after drying. Upon addition to and processing with the thermoplastic polymer composition, these hard agglomerates cannot be re-dispersed into individual particles. Further, such agglomerates may inhibit the activity of the flame retardant in the thermoplastic polymer composition by decreasing the active flame retardant surface area available, and can interfere with physical and aesthetic properties, such as flexural and impact strength, of the final polymer composition.
[0010] Thus, there remains a need in the art for a solid, stable dispersion which imparts acceptable levels of fire retardation to a thermoplastic polymer-containing composition, while simultaneously retaining the strength properties of the thermoplastic polymer, such as impact resistance, and maintaining flexural properties.
SUMMARY OF THE INVENTION
[0011] In brief, the present invention is directed to the formation of a solid, dispersible flame retardant powder, by transferring a solid flame retardant, via electrostatic and packing interactions, from an emulsion to a wax, polymer, organic liquid or organic solid carrier. Additionally, the invention is directed to the use of such particles as flame retardants in a polymer composition.
[0012] A further aspect of the invention to provide a solid, dispersible powder, suitable for use as a flame retardant in a polymer-containing composition, which minimizes the loss of mechanical strength and flexibility of the thermoplastic polymer-containing composition, while maintaining acceptable levels of fire retardant properties.
[0013] Another aspect of the invention is to provide a solid flame retardant associated with an organic liquid carrier suitable for use as a flame retardant in a polymer-containing composition, which minimizes the formation of defects in the polymer composition while imparting acceptable levels of flame retardant properties to the polymer.
[0014] Another aspect of the invention is to provide a process for the formation of a solid, dispersible flame retardant product comprising a wax, polymer, organic liquid or organic solid central core, acting as a carrier, and containing one or more covering layers of a flame retardant, comprising: 1) addition of a wax, polymer, organic liquid or organic solid to a fluid carrier/surfactant solution with sufficient mixing, and heat if necessary, to form an emulsion; 2) deposition of a solid flame retardant powder on the surface of the wax, polymer, organic liquid or organic solid to form a particle containing small emulsified particles of wax, polymer, organic liquid or organic solid surrounded by one or more covering layers of a solid, flame retardant powder in a fluid carrier; 3) settling of the wax, polymer, organic liquid or organic solid core material covered with the solid, flame retardant powder in the fluid carrier; and 4) removal of the fluid, leaving a flame retardant consisting of a wax, polymer, organic liquid or organic solid central core acting as a carrier, and containing one or more covering layers of a flame retardant.
[0015] Thus, according to one embodiment of the present invention, a wax, polymer, organic liquid or organic solid is added to a first fluid carrier, preferably water, along with a first surfactant, and the combination of first surfactant, fluid carrier, and wax, polymer, organic liquid or organic solid is mechanically agitated to form the emulsion. Preferably, the first fluid carrier is heated. Further, if a wax, polymer, or organic solid is used, the wax, polymer, or organic solid preferably has a sufficiently low melting temperature such that, upon addition to the heated first fluid carrier, the wax or polymer melts. If the wax, polymer, or organic solid has been chosen such that it will not melt in the heated first fluid carrier, then preferably the wax, polymer, or organic solid has been previously processed to a particle size of less than one hundred microns. Such processing (e.g., emulsification of the core material and/or milling) are well known to those skilled in the art. Preferably, the wax, polymer, or organic solid has been previously processed to a particle size of less than fifty microns. In accordance with the preferred embodiment, the wax used is a hydrogenated castor oil. The dispersible powder product includes about 1% by weight to about 50% by weight core material, preferably about 2% to about 20% core material, based on the dry weight of the flame retardant particles surrounding the core material.
[0016] The particular first surfactant used to form the emulsion between the wax, polymer, organic liquid or organic solid and the first fluid carrier is not critical and can be any surfactant possessing a charge separation (e.g., a dipole moment or an ionic charge) greater than that of water (1.76 D) and capable of forming an emulsion, via agitation, between the wax, polymer, organic liquid or organic solid core material, and the first fluid carrier. In accordance with the preferred embodiment, the first surfactant used is a pyridine salt, preferably hexadecylpyridinium chloride monohydrate.
[0017] Other examples of useful pyridinium salts include: dodecylpyridinium bromide; dodecylpyridinium chloride; dodecylpyridinium iodide; butadecylpyridinium bromide; butadecylpyridinium chloride; hexadecylpyridinium bromide; hexadecylpyridinium chloride; octadecylpyridinium bromide; and octadecylpyridinium chloride. The preferred pyridinium salts are halogenated pyridinium salts, having a carbon chain length of C 12 to C 18 , and will function as emulsifiers. The micelle concentration of the compounds decreases with an increase in carbon chain length and also decreases with increasing atomic number of the halogen ion used (hence the limited use of the iodide ion salts).
[0018] The first surfactant lowers the surface tension at the interface between the wax, polymer, organic liquid or organic solid and the first fluid carrier, allowing the particle size of the wax, polymer, or organic liquid core material droplets to be minimized. In addition, the first surfactant acts as an emulsifier, reducing the coalescence of wax, polymer, organic liquid or organic solid particles in the first fluid carrier and increasing the stability of small wax, polymer, organic liquid or organic solid particles. Further, the first surfactant, via electrostatic (e.g., ion-dipole or dipole-dipole) interactions, generates an electrostatic charge at the surface of the wax, polymer, organic liquid or organic solid core material.
[0019] A flame retardant or flame retardant composition is then added to the agitating emulsion. Such flame retardant or flame retardant compositions include one or more flame retardants preferably selected from the group consisting of antimony trioxide, antimony pentoxide, decabromodiphenyloxide, hexabromo-cyclododecane, melamine phosphate, melamine pyrophosphate, ammonium polyphosphate, resorcinol diphosphate, diammonium phosphate, antimony metal, sodium antimonate, mixed metal oxides of zinc and magnesium, zinc sulfide, bismuth subcarbonate, zinc borate, barium metaborate, molybdenum oxide, ammonium octamolybdate, ferrocene, magnesium hydroxide, bis-tribromophenoxy ethane, tetrabromobisphenol A, zinc stannate, malamine cyanurate, ethylene bis-tetrabromophthalimide, aluminum trihydrate and mixtures of any two or more of the foregoing. Preferably, the flame retardant composition is antimony trioxide in water and/or an organic liquid carrier, where the antimony trioxide has been combined with a second surfactant and then milled to a particle size of less than 0.1 micron. Such milling methods (e.g., wet agitated media milling) are well known to those skilled in the art. To achieve the full advantage of the present invention, the second surfactant possesses a charge separation (e.g., a dipole or an ionic charge). Such compounds with a charge separation include anionic, cationic, or amphoteric surfactants. Specifically, such surfactants include lignosulfates, phosphate esters, sulfated alcohol ethoxylates, alkylbenzenesulfonates, sulfonate esters, naphthalene sulfonates, α-olefinsulfonates, sodium silicates, N-acrylsarcosinates, polyacrylates, polycarboxylic acid salts, polymaleic anhydride/polyethylene glycol (PMA/PEG) blends, long-chain amines, amine oxides, amine ethoxylates, quaternary ammonium salts, alkyl betaines, and imidazolines, and blends thereof. In accordance with the most preferred embodiment, the second surfactant is Borresperse Na (LignoTech USA, Inc.), a sodium lignosulfate with a measurable dipole moment. The second surfactant acts as a dispersant, dispersing the antimony trioxide evenly throughout the second fluid carrier and reducing the tendency of flame retardant particles to associate into hard agglomerates. Further, the second surfactant acts to generate a charge at the surface of the flame retardant.
[0020] The flame retardant is then deposited on the surface of the wax, polymer, organic liquid or organic solid core material through a series of electrostatic (dipole-dipole or ion-dipole) interactions. The resultant particles, or “prills”, which are composed of a central core of wax, polymer, organic liquid, or organic solid, surrounded by one or more, preferably multiple, layers of loosely packed flame retardant solid particles, rapidly settle out of solution. The fluid can then be decanted away or otherwise separated from the particles, and the particles dried using any drying method known to those skilled in the art.
[0021] The advantages of such a formation of a solid, dispersible flame-retardant powder are manifest. For example, by transferring the active flame retardant from the liquid phase to the solid phase, the flame retardant may be easily dispersed throughout the polymer-containing composition, while maintaining flexibility, mechanical strength and currently acceptable flame-testing criteria, such as the LOI (limiting oxygen index) and UL-94 (Underwriters Laboratories) standards. Dispersions of such particles are also convenient, since they allow the flame retardant to be easily transported.
[0022] Solid dispersions also minimize the level of waste flame retardant, and ease recycling of material unattached to the wax, polymer, organic liquid or organic solid core material. Typically, an excess of flame retardant will be used in the system. By maintaining the flame retardant in an emulsion, upon decantation any excess flame retardant particles can be easily recycled by separation of the second fluid carrier and surfactant from the first fluid carrier, followed by addition of a further amount of wax, polymer, organic liquid or organic solid in the first fluid carrier.
[0023] In addition, solid dispersions simultaneously inhibit flocculation of the flame retardant into larger than 2 micron particles. These flocs, which are formed from individual flame retardant particles which associate via hydrophobic interactions and capillary pressure, have a particle size larger than 2 microns, and are unattached to the wax, polymer, organic liquid or organic solid core material. Upon decantation of the fluid carrier and drying, these flocs dry as hard particles of flame retardant which can fail to redisperse upon addition to a thermoplastic polymer melt, generating flaws in the thermoplastic polymer. The 2 micron agglomerates present in the solid dispersions of the present invention, are held together by electrostatic forces weaker than those which maintain the structural integrity of a particle unattached to the wax, polymer, organic liquid or organic solid. While sufficient to maintain the structural integrity of the agglomerate under normal handling conditions, upon addition to a polymer containing composition, these agglomerates collapse, and redisperse to the individual primary particle size (e.g., less than 1 micron). Preferably, the individual primary particle size is below 0.5 micron. Most preferably, the individual primary particle size, e.g., less than about 1 micron, preferably less than about 0.5 micron, more preferably less than about 0.1 micron.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The present invention may be best understood by reference to the following detailed description of a preferred embodiment, when considered in conjunction with the following drawings. The drawings are intended to represent one possible mechanism of formation for the final prill structure, and should not be construed as a limitation on the process by which the solid, dispersible flame retardant powder is obtained. Thus,
[0025] [0025]FIG. 1 is a diagram of a micelle formed by the interaction of a wax, polymer, or organic liquid and a first surfactant;
[0026] [0026]FIG. 2 is a diagram of a micelle formed by the interaction of a powdered, solid flame retardant material and a second surfactant;
[0027] [0027]FIGS. 3A and 3B are diagrams of one mechanism for the deposition of the initial layers of flame retardant onto the wax, polymer, or organic liquid core material;
[0028] [0028]FIGS. 4A and 4B are diagrams of one mechanism for the formation of 2 micron agglomerates from individual particles of flame retardant;
[0029] [0029]FIGS. 5A and 5B are diagrams of one mechanism for the deposition of the outer layers of flame retardant on the prill structure; and
[0030] [0030]FIG. 6 is a diagram of the structure of the dispersible powder formed by the process of the invention;
[0031] [0031]FIG. 7 is a transmission electron photomicrograph detailing the outer structure of a dispersible powder formed by the process of the invention;
[0032] [0032]FIG. 8 is a transmission electron photomicrograph showing the dendritic structure of the outer layers of flame retardant in a dispersible powder formed by the process of the invention;
[0033] [0033]FIG. 9 is a transmission electron photomicrograph detailing microscopic dispersion in a acrylonitrile-butadiene-styrene (ABS) containing composition compounded with 5% by weight of a dispersible powder formed by the process of the invention;
[0034] [0034]FIG. 10 is a transmission electron photomicrograph detailing microscopic dispersion in a acrylonitrile-butadiene-styrene (ABS) containing composition compounded with 4% by weight MICROFINE® AO5 antimony trioxide (Great Lakes Chemical Corp.) commercial flame retardant (hereinafter “AO5”);
[0035] [0035]FIG. 11 is a transmission electron photomicrograph detailing microscopic dispersion in a acrylonitrile-butadiene-styrene (ABS) containing composition compounded with 4% by weight of the commercial flame retardant Timonox Red Star (Great Lakes Sales (UK) Ltd.);
[0036] [0036]FIG. 12 is a graph of peak force measurements obtained in an impact resistance test, using an ABS containing composition compounded with varying percentages by weight of a dispersible powder formed by the process of the invention;
[0037] [0037]FIG. 13 is a graph of peak energy measurements obtained in an impact resistance test, using an ABS-containing composition compounded with varying percentages by weight of a dispersible powder formed by the process of the invention;
[0038] [0038]FIG. 14 is a graph of flexural modulus measurements obtained in a three-point bend flexural test, using an ABS-containing composition compounded with varying percentages by weight of several antimony trioxide-based flame retardants;
[0039] [0039]FIG. 15 is a graph of flexural strength measurements obtained in a three-point bend flexural test, using an ABS-containing composition compounded with varying percentages by weight of several antimony trioxide-based flame retardants.
[0040] [0040]FIG. 16 is a graph of fail energy of decabromodiphenyloxide (DBDPO) on castor wax particles, in comparison to other flame retardants;
[0041] [0041]FIG. 17 is a graph of fail energy of antimony trioxide on castor wax particles (Dispersible Powder AT), made in accordance with Example 1, using hexadecylpyridinium bromide instead of hexadecyclpyridinium chloride, in comparison to prior art antimony trioxide (hereinafter “AT”) particles, showing that the products are essentially identical using either emulsifier;
[0042] [0042]FIG. 18 is a graph showing some mechanical properties of a nylon polymer containing the dispersible powdered AT on an amide wax core, compared to TxRs (Timonox Red Star) antimony trioxide (hereinafter “Red Star”); and
[0043] [0043]FIG. 19 is a graph showing some mechanical properties of polypropylene fiber containing the dispersible powdered AT on an ester wax core, alone and with a brominated graft copolymer in comparison to the copolymer with and without a typical AT.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] Referring to FIG. 1, each individual prill structure 10 contains a wax, polymer, organic liquid, or organic solid core material 12 , which upon interaction with first surfactant 14 in a fluid carrier 16 (e.g., water), forms a stable micellar structure in which the hydrophobic portion 14 a of the first surfactant 14 is either inserted into or is closely associated with the outer surface of the surface of the wax, polymer, or organic liquid core material 12 , while the charged, hydrophilic portion 14 b of the first surfactant 14 interacts with the fluid carrier 16 . This results in the wax, polymer, organic liquid or organic solid core/surfactant micelle having a net charge δ at its surface. Similarly, as shown in FIG. 2, the flame retardant particles 18 , upon interaction with the second surfactant 20 in a second fluid carrier 22 , forms a separate, stable micellar structure in which the hydrophobic portion 20 a of the second surfactant is closely associated with the surface of the flame retardant particle 18 , while the hydrophilic portion 20 b interacts with the fluid carrier 22 . The second surfactant-flame retardant micelle has a net charge δ at the micelle surface, which is opposite to the charge δ presented by the first surfactant 14 at the surface of its micelle.
[0045] The flame retardant particles 18 are believed to be deposited onto the wax, polymer, organic liquid or organic solid core material 12 in two stages. Referring to FIG. 3B, the initial layers of flame retardant are comprised of individual flame retardant particles 18 approximately 0.1 micron or smaller in diameter. As shown in FIG. 3A, these particles 18 are deposited on the surface of the wax, polymer, organic liquid or organic solid core material 12 via charged particle electrostatic attraction between micelles containing the charged wax, polymer, organic liquid or organic solid carrier core material 12 and micelles containing the individual particles of flame retardant 18 . Upon interaction, the flame retardant 18 tends to adhere to the wax, polymer, organic liquid or organic solid core material 12 due to both charged particle attraction and a preference for interaction with other particles of flame retardant 18 as opposed to first fluid carrier 16 and second fluid carrier 22 . This results in the deposition of several layers of flame retardant particles 18 on the surface of the wax, polymer, organic liquid or organic solid core material 12 , to an approximate thickness of 300-500 nm.
[0046] The outer layers of flame retardant particles 18 are believed to be a combination of individual primary particles 18 , having a particle size of approximately 1 micron or smaller in diameter, and agglomerates of flame retardant particles 26 up to 2 microns in diameter, as shown in FIG. 6. Preferably, the size of the individual primary particles 18 is below 0.5 micron, more preferably, less than 0.1 micron in diameter. Referring to FIG. 4A, these agglomerates 26 are formed by the interaction of flame retardant particles 18 , first surfactant 14 , and second surfactant 20 in fluid carriers 16 and 22 . Because the amount of second surfactant 20 is insufficient to occupy all available sites on the flame retardant particles 18 , first surfactant 14 occupies several sites on the surface of a number of flame retardant particles 18 . This results in a number of individual flame retardant particles 18 exhibiting opposing charges on opposite sides of the particle, generating a dipole moment. These bipolar flame retardant particles 24 , through electrostatic interactions with each other, form bipolar agglomerates 26 , as shown in FIG. 4B. Referring to FIG. 5A, these agglomerates 26 seed the deposition of the outer layers of flame retardant particles 18 via electrostatic interactions with flame retardant particles 18 previously deposited onto the wax, polymer, organic liquid or organic solid core material 12 . In the final layers of flame retardant particles 18 , seeding of subsequent layers of flame retardant 18 by agglomerates 26 often takes the form of long, dendritic clusters 28 , as shown in FIG. 5B. These dendritic clusters 28 are composed of agglomerates 26 and individual flame retardant particles 18 . Such clusters 28 can reach a length of several microns, e.g., 2-10 microns.
[0047] After separation from the fluid carriers 16 and 22 and drying, each individual prill structure 10 is a spherical particle approximately 1-20 microns in size. A small amount of first fluid carrier 16 and second fluid carrier 22 , typically 1-3% total by weight, remains associated with the prill 10 . Referring to FIG. 6, the theoretical structure of the resultant prill 10 is a wax, polymer, organic liquid or organic solid central core 12 surrounded by inner layers of individual flame retardant particles 18 and outer layers comprised of both individual flame retardant particles 18 and agglomerates 26 , which are comprised of flame retardant particles 18 . The flame retardant particles 18 comprising the exterior of the prill 10 is kept in close association with the wax, polymer, organic liquid or organic solid central core 12 through both electrostatic interactions between the wax, polymer, organic liquid or organic solid core material 12 and flame retardant particles 18 , and electrostatic interactions between individual flame retardant particles 18 and agglomerates 26 . Upon addition to a thermoplastic polymer composition and compounding, these electrostatic attractions are insufficient to maintain the structural integrity of the prill 10 , causing both the flame retardant particles 18 and the agglomerates 26 to re-disperse, as individual flame retardant particles 18 , to their initial primary particle size of about 1 micron or less, preferably less than 0.5 micron, more preferably less than about 0.1 micron.
[0048] It will be apparent to those skilled in the art that the wax, polymer, organic liquid or organic solid core material 12 should be chemically compatible with the polymer composition into which the flame retardant will be incorporated. Similarly, the fluid carrier 16 used for the wax, polymer, organic liquid or organic solid core material 12 should be chemically compatible with the fluid carrier 22 used for the flame retardant particles 18 (e.g., two aqueous carriers). While substantially all flame retardant particles 18 present in fluid carrier 22 can be adsorbed onto the wax, polymer, organic liquid or organic solid substrate 12 , when the weight ratio of wax, polymer, organic liquid or organic solid core material 12 to flame retardant particles 18 is low, the thickness of the flame retardant layer electrostatically adhered to the wax, polymer, organic liquid or organic solid core material 12 tends to increase. Simultaneously, the packing density of the outer layers of flame retardant particles 18 and agglomerates 26 in the prill 10 tends to decrease. With additional buildup of subsequent layers of flame retardant particles 18 , as the radius of the flame retardant layers, measured outwardly from the outer surface of the core material 12 , begins to surpass the radius of the central core 12 , these less dense layers become vulnerable to separation from the central core material 12 . For example, in the preferred embodiment, where the radius of the central core material 12 is approximately 20 microns, layers of flame retardant particles 18 become vulnerable to separation when their exceeds 20 microns, for a total particle size of 80 microns. These separated layers are subsequently dried as hard, unattached flocs of flame retardant particles 18 . Such hard flocs will not re-disperse upon addition to a polymer composition and subsequent compounding, which can lead to flaws in the polymer matrix.
EXAMPLES
[0049] The following examples are illustrative of various preferred embodiments of the above described invention. Further examples should be readily apparent to those skilled in the art.
Example 1
Antimony Trioxide (AT) on a Castor Wax Core
[0050] Hexadecylpyridinium chloride monohydrate was added to water at a temperature of greater than 87° C. at a concentration of approximately 5×10 −3 M/L. To this solution, castor wax was added, either in powdered or flake form. Mechanical agitation was started as the wax began to melt in solution, forming an emulsion. Once the wax had completely melted, antimony trioxide slurry, previously fluid-milled to a particle size less than 0.1 micron, (Azub™/AT-40 hereinafter “AT-40”), Great Lakes Chemical Corp.) was added to the agitating emulsion. The resultant prills immediately began to form and settled out of solution once mechanical agitation was stopped or slowed. The resultant liquor was removed by decantation, and the prills dried using an atomizing wheel spray dryer. The resultant prill structure, when dried, typically has a particle size of 1-20 microns, with a continuous active antimony trioxide coating layer, typically 1-10 microns in thickness.
[0051] The product manufactured is a free flowing powder. Transmission electron microscopy shows the structure of the flame retardant particles is that of a central wax core with multiple layers of antimony trioxide loosely packed around the center, as shown in FIG. 7. While in powder form, individual flame retardant particles tend to associate in dendritic clusters at the surface of the prill, as shown in FIG. 8. Adsorption isotherms have shown that substantially all of the antimony trioxide is adsorbed onto the surface of the wax substrate.
Example 2
AT on a Castor Wax Core (Example 1) in Acrylonitrile-Butadiene-Styrene (ABS)
[0052] Transmission electron microscope studies were used to study the dispersion characteristics of the powder, manufactured in accordance with Example 1, in an acrylonitrile-butadiene-styrene (ABS) polymer-containing composition (Cycolac™, General Electric Corp.). The electron micrograph showed the powder had superior dispersion characteristics compared to several standards. While the micrograph does show limited agglomeration of antimony trioxide particles (see FIG. 9), the majority of the material, upon addition to the ABS composition, redispersed back to an individual particle size of less than 0.1 micron, which is smaller than the smallest polybutadiene particles naturally present in the ABS polymer-containing composition (0.2 μm). In contrast, as shown in FIGS. 10 - 11 , both Red Star and AO5, two commercially available flame-retardant antimony trioxide formulations, had poor dispersion capabilities, with a number of antimony trioxide particles which are larger than the smallest polybutadiene particles naturally present in the ABS polymer-containing composition, generating flaws in the ABS polymer-containing composition.
Example 3
Processing of AT (Example 1) in ABS
[0053] The flame retardant dispersible powder, made in accordance with Example 1 was added to an ABS composition, and tested for its effect on processing of the resulting ABS-containing composition. Typical compounding took place on a twin-screw extruder under varying conditions, as shown in Table 1.
[0054] Typical values for the process mixing torque and die pressure exerted during processing are shown in Table 2 . Adding the solid flame-retardant dispersible powder reduced the mixing torque by approximately 12% and reduced die pressure by 0.2-0.3 MPa, similar to the reduction seen when castor wax is added to other antimony trioxide compositions. Absolute torque was comparable to that experienced at common loadings of AO5, while the die pressure exerted was 2-6% greater than that experienced using AO5. It is believed these effects are due to the lowering of the viscosity, as measured by capillary rheology, of the flame retardant-containing thermoplastic composition compared to unfilled ABS. Such a loss of viscosity may result in pseudoplastic behavior, where the rate of flow of the ABS composition, in relation to the shearing stress, increases at a higher than normal rate.
Example 4
Impact Properties of AT (Example 1)
[0055] The flame retardant dispersible powder, containing 85% by weight antimony trioxide and 15% by weight castor wax, made in accordance with Example 1, was added to an ABS composition and tested for its effect on impact properties, compared to several standards. In general, the addition of antimony trioxide-based particulate flame retardants had the effect of lowering the mean peak and main failure energies of the impact strength of the polymer composition, as defined by Charpy sample bars (see Table 3). The energies were measured on a Rosand Instrumented Falling Weight Impact Testing (IFWIT) 5 machine. The loss of the respective energies was proportional to the particle size of the additive. It can be clearly seen that the formulation containing 5% dispersible powder had a minimal effect on the impact properties of the polymer composition. Even at a flame-retardant loading of 11%, the impact loss was superior to that of much lower loadings of Red Star and approximately equal to that of AO5.
Example 5
AT (Example 1) Having Varying Ratios of AT/Core
[0056] The flame retardant dispersible powder, containing varying levels of flame retardant relative to the wax carrier core material, made in accordance with Example 1, was added to an ABS composition and tested for their effects on impact properties. In all cases, the total level of flame retardant added was kept constant at 4% antimony trioxide by weight, based on the weight of the ABS polymer. Relative to unfilled ABS, the addition of the solid flame retardant generally increased both the peak force and peak energy measurement of the composition, as shown in FIGS. 12 - 13 . It is believed, in the case where both the peak force and peak energy are lower than that of unfilled ABS, the weight ratio of antimony trioxide to castor wax is below the critical level for prill stability, causing flame retardant to separate from the wax prior to processing, generating flaws in the ABS polymer.
Example 6
80% AT/20% Castor Wax Core
[0057] A dispersible powder containing 20% by weight castor wax and 80% by weight antimony trioxide was manufactured in accordance with Example 1, added to an ABS composition, and the flexural properties of the resultant ABS-flame retardant compositions were determined using a three point bend flexural test. Both the flexural modulus and flexural strength determination conform to American Society of Testing and Materials (ASTM) D790/BS2782 Part 3 Method A where:
E b =( L 3 m )/(4 bd 3 ) and flexural strength σ b =(3 FL )/(2 bd 2 )
[0058] where L is the support span, b is the sample width, F is the maximum load, d is the sample thickness, and m is the slope of the linear portion of the curve.
[0059] The results for flexural modulus tests are given in FIG. 14, and the results for the flexural strength tests are shown in FIG. 15. In general, the addition of the solid dispersion of the present invention to the ABS-containing composition increased flexural modulus by 1% relative to unfilled ABS, and decreased flexural strength by 2%. When ABS was filled with typical loadings of both AO5 and Red Star, the flexural modulus decreased by 12% and 13%, respectively, while flexural strength was unchanged for microfine AO5 and decreased by 7% for Red Star.
Example 7
Improved Fire Retardancy of ABS
[0060] Dispersible powders containing various percentages of antimony trioxide by weight, manufactured in accordance with Example 1, were added to ABS compositions of varying thicknesses and flame retardancy tested using the LOI (ASTM D 2863) and Underwriters Laboratories UL-94 standards. The results are shown in Tables 4 and 5. Addition of both wax alone and wax with solid flame retardant to ABS had no effect on the LOI, and resulted in either burning or high levels of flaming drops. When halogen compounds were added in conjunction with the solid flame retardant, LOI increased dramatically. At 1.6 mm thickness ABS, most formulations had a limited flame retardant effect by the UL-94 standard; addition of 20% by weight tetrabromobisphenol A (BA-59P of Great Lakes Chemical Corporation), a bromine compound, had a limited effect on the UL-94 rating of the ABS/flame retardant composition, but the LOI rating was comparable to that of other flame retardant compositions. Addition of octabromodiphenyl oxide (OBDPO, DE-79 of Great Lakes Chemical Corporation) and decabromodiphenyl oxide (DE-83R of Great Lakes Chemical Corporation) appeared to have little effect on the flame retardant compositions. At 3.2 mm thickness ABS, addition of the solid flame retardant in conjunction with halogen compounds allowed the ABS composition to receive the most stringent UL-94 rating.
TABLE 1 Typical Extruder Conditions (Based On APV MP30TC Twin Screw Extruder) Extruder temperature profile (° C.) [die-feed zone] Screw Speed Die Zone 2 Zone 3 Zone 4 Zone 5 Feed (rpm) 215 210 208 190 170 185 200
[0061] [0061] TABLE 2 Influence Of Dispersible Powder And Wax On Compounding Variables Compounder Torque Die Pressure Compound Speed (rpm) (%) (MPa) ABS* 200 76-80 2.87 ABS* + 1 wt % 200 72-76 2.80 castor wax ABS* + 3 wt % 200 62-68 2.72 castor wax ABS* + dispersible 200 64-66 2.55 powder (3 wt % AT) ABS* + dispersible 200 63-66 2.65 powder (10 wt % AT) ABS* + 10 wt % 200 67-69 2.51 AO5 ABS* + 13 wt % 200 50-60 2.34 AO5 + castor wax
[0062] [0062] TABLE 3 Peak And Failure Energies Of Charpy Notched Test Bars Mean Difference Mean Difference Peak to blank Failure to blank Formulation Energy (J) (%) Energy (J) (%) ABS* blank 0.51 — 1.17 — ABS* + 4 wt % 0.22 −43% 0.80 −32% Red Star ABS* + 4 wt % 0.32 −37% 0.85 −27% Red Star + 1 wt % castor wax ABS* + 4 wt % 0.41 −19% 0.99 −15% AO5 ABS* + 4 wt % 0.43 −15% 1.05 −10% AO5 + 1 wt % castor wax ABS* + 5 wt % 0.51 0% 1.20 0.02 dispersible powder ABS* + 11 wt % 0.41 −17.9% — — dispersible powder ABS* + 10 wt % 0.37 −25.5% — — AO5 + 3 wt % castor wax
[0063] [0063] TABLE 4 UL-94 And LOI Flame Test Results Dispersible Powder Antimony Trioxide On 20% By Weight Castor Wax Total UL-94 Burn UL-94 Total Burn LOI (1.6 mm) (secs) Comments (3.2 mm) (secs) Comments ABS blank 18.3 Fail Burned to clamp Fail Burned to clamp ABS + castor wax (1%) 17.6 Fail Burned to clamp Fail Burned to clamp ABS + dispersible powder 18.2 Fail Burned to clamp Fail Burned to AT (5.2%) clamp ABS + dispersible powder 18.4 Fail Burned to clamp Fail Burned to AT (4%) clamp ABS + dispersible powder 24.2 V-2 81 Flaming drips V-0 4 AT (5%) + FF680 ™* (18%) ABS + dispersible powder 27.6 V-2 39 Flaming drips V-0 5 AT (5%) + BA-59P ™** (18%) ABS + dispersible powder 28.8 V-2 6 Flaming drips V-0 5 AT (5%) + DE-79*** (18%) ABS + dispersible powder 30.2 V-2 21 Flaming drips V-0 4 AT (5%) + F-2016 ™**** (18%) ABS + 6 phr dispersible powder 26.6 V-0 AT + 18 phr DE-79 ™*** ABS + dispersible powder 26.5 V-0 AT (5.7%) + FF-680 ™*** (18%) ABS + dispersible powder 27.5 V-2 AT (5.7%) + BA-59P ™ (20%) ABS + dispersible powder AT 29.5 V-0 (5.7%) + dispersible powder DE-83R ™ (20%) ABS + Red Star (5%) 19 Fail Burned to clamp Fail Burned to clamp ABS + Red Star (5%) + 18.2 Fail Burned to clamp Fail Burned to castor wax (1%) clamp ABS + Red Star (5%) + 25.4 V-2 11 Flaming drips V-0 10 FF-680 ™ (20%) ABS Red Star (5%) + 25.3 V-2 28 Flaming drips V-0 5 BA-59P ™ (20%) ABS + Red Star (5%) + 28.7 V-2 7 Flaming drips V-0 22 DE-79 ™ (20%) ABS + Red Star (5%) + 29 V-0 4 Drips, no ignition V-0 0 F-2016 ™ (20%) ABS + 6 phr Red Star + 26.1 Fail 20 phr DE-79 ™
[0064] [0064] TABLE 5 UL-94 And LOI Flame Testing Data Dispersible Powder AT On 13% By Weight Castor Wax UL-94 Total Burn LOI (1.6 mm) (secs) ABS blank 18.3 Fail ABS + castor wax (0.7%) 17.6 Fail Dispersible powder AT (5.2%) 18.2 Fail Dispersible powder AT (4%) 18.4 Fail Dispersible powder AT + 24.2 V-2 8 FF-680 ™ (18%) Dispersible powder AT + 27.6 V-0 5 BA-59P ™ (20%) Dispersible powder AT + 28.8 V-0 4 DE-79 ™ (18%) Dispersible powder + F-2016 ™ 30.2 V-0 5 (18%)
Example 8
Higher Percentage of Hexadecylpyridinium Chloride
[0065] Decabromodiphenyloxide (DE-83R) on a Castor Wax Core in ABS Polymer
[0066] The flame retardant dispersible powder was made in accordance with Example 1, except hat a slightly higher concentration of hexadecylpyridinium chloride was used (7.5×10 −3 M/L) and the DE-83R coating layer had a thickness of 0.2 μm instead of 0.1 μm. The size distribution of the dried prills was 10-40 μm, the DE-83R layer thickness being 5-20 μm (there is a thicker layer due to a lower packing density associated with the larger particle size used). The component manufactured was tested along with various ABS controls, a AO5 control, a 0.1 μm antimony Azub™ control with and without unmilled DEDPO, and finally a compound with milled antimony and milled DBDPO (LOI and UL-94 results previously given in Table 4). Mechanical and fire testing is summarized in Table 6, and in FIG. 16:
TABLE 6 Dispersible Dispersible Powder AT* Dispersible Powder (5%) Powder AT* AO5 AT* Dispersible Powder (5%) ABS+ Blank (4%) (5%) DE-83R (15%) DE-83R (12%) Fail Energy (J) 1.40 1.10 1.42 1.21 0.74 (s.d.) (0.10) (0.08) (0.08) (0.10) (0.18) LOI 18.3 18.9 18.4 29.5 26.8 UL-94** Fail Fail Fail V-0 V-2
[0067] The graphical representation of the fail energy (FIG. 16) illustrates the benefits to mechanical properties of the smaller particle size and subsequent phase transfer of the powdered DE-83R (original particle size of 6 μm) onto a core carrier.
Example 9
Hexadecylpyridinium Bromide
[0068] The flame retardant dispersible powder was made in the same manner described in Example 1, except that hexadecylpyridinium bromide was used as the emulsifier instead of hexadecylpyridinium chloride. This results in an identical product, in size, and the like, to the product of Example 1. There are slight differences in the melting point of the bromide version of the emulsifier, but this is irrelevant. Table 7, below, summarizes the comparison of mechanical and fire properties between the bromide and chloride version of the hexadecylpyridinium salts:
TABLE 7 Dispersible Dispersible powder AT* powder AT* (5%) (5%) ABS+ Blank AO5 Cl ion Br ion Fail Energy 1.40 1.10 1.42 1.41 (J) standard deviation (0.10) (0.08) (0.08) (0.12)
[0069] No UL-94 or LOI tests were carried out since there were no bromine compounds present in the resulting flame-retarded ABS composition. Only a comparison between Br and Cl − variations of the emulsifying agents tested for mechanical properties. The carryover of the salt to the final product is minimal and would not effect flame retardant properties (carryover probably of the level compounds is best shown graphically, to be essentially identical, as shown in FIG. 17.
Example 10
AT on an Amide Wax Core
[0070] The flame retardant dispersible powder was made in the same manner described in Example 1, except that an amide wax (melting point 160° C.) was used instead of castor wax. The wax used was Hoechst Wax C. The amide wax is a low molecular weight polymer. The wax is supplied in a fine form (5-10 μm) giving an increased surface area over less finely divided forms. The resulting dispersible powder AT flame retardant powder was manufactured having 10 wt % wax and 90 wt % AT via the following procedure:
[0071] Hexadecylpyridinium chloride was added to water at a temperature of greater than 83° C. at an approximate concentration of 7.5×10 −3 M/L. The solution was then mechanically agitated. To this agitated solution the finely divided wax powder was slowly added, forming a dispersion of the wax particles in water. The dispersion was wetted and consequently stabilized by the adhesion of the hexadecylpyridinium ion to the surface of the wax particle, as shown schematically in FIG. 2. The hydrophobic tails of the ions pack tightly around the outer surface of the wax core, leaving a hydrophilic, positively charged, dispersant layer around each core particle (the positively charged layer stops the particles from forming flocs or agglomerates in solution).
[0072] Once the amide wax material was completely dispersed, as in Example 1, the antimony trioxide slurry was followed by the layering mechanism, settling, decanting and drying, as in accordance with Example 1.
[0073] The procedure produces a very fine, dispersible powder product with a size of 10-20 μm with a calculated antimony trioxide layer thickness of 5-10 μm.
[0074] This material was compounded into a standard unfilled injection molding grade of Nylon 6,6 (DuPont Zytel 101F) and impact strength tested as a measure of physical performance and impact strength tested as a measure of physical performance. Table 8 below, and FIG. 18, summarizes the testing results.
TABLE 8 Dispersible Read Star Blank + 0.4% powder AT (4%) + Blank Wax C (4.4%)** 0.4% Wax C Fail Energy 1.52 1.60 1.44 1.09 (J) standard deviation (0.20) (0.21) (0.26) (0.34)
[0075] Again, as shown graphically in FIG. 18, there is a very large distinction between dispersible powder AT material and the standard grade of Red Star. The Red Star in the trials also had 0.4% wax added to allow for the plasticizing and lubricating effect of the wax in all samples.
[0076] The dispersible powder AT material added at 4.4 wt % (4% AT and 0.4% Wax C) has retained 94.7% of the strength of the blank compared to only 71.7% retained by the standard grade (Red Star).
Example 11
Flame Retardant Dispersible Powder in Thermoplastic Fibers
[0077] Currently, the incorporation of solid particulate flame retardants into thermoplastic fiber compounds causes severe processing problems when spinning and weaving the fibers. To produce thermoplastic fibers (usually PET, polyamide (nylon) or PP) a melt is produced (usually in a single screw extruder) and is metered (pumped) through a filter pack and then a set of spinnerettes (dies). For the production of fibers during this testing, a lab scale fiber line was used. This fiber line has a 120 hole 0.52 mm trilobal filament spinnerette. After material has been passed through the spinerettes, it is passed around a series of rollers. The first set of rollers are matched in rotational speed to the speed of extrusion of the machine, the second set reheats the filaments (to approximately 60-70° C.), and the third set rotate at an increased rpm. This increase in rpm causes the fibers to draw. Typically a draw ratio of 1:4 is used. This reduces the cross sectional size of the fiber.
[0078] If there are any large particles within the fiber, fibers have a tendency to break on drawing. Also, any particles near the surface of the fiber cause the fiber to have a relatively abrasive surface, thus wearing any thread guides used during later processes. The process and materials of the present invention should eliminate these problems.
[0079] A dispersible powder AT was produced using antimony trioxide and an ester wax (Hoechst Wax E). The Wax E has a melting point of 82° C., so the initial processing was carried out above this temperature and in accordance with Example 1. The resultant powder was similar in all characteristics to the product of Example 1. The material had 18 wt % wax and 82 wt % antimony trioxide.
[0080] This powder was processed on a twin screw extruder into an unfilled natural color polypropylene polymer (Targor Novalen 1100N). The material was compounded as a dispersible powder AT—only compound, as well as with a brominated component GPP-39 (Great Lakes Chemical Corporation), which is a melt-blendable brominated graft copolymer of polypropylene and dibromostyrene.
[0081] Following extrusion and granulation, the compounds were passed through the fiber line. The materials were tested for strength using an Instron tensile testing apparatus. The apparatus measured the applied load on fibers against the applied displacement. Two measurements were observed. The initial yield of the fiber and the maximum load of the fiber, as shown in Table 9.
TABLE 9 Dispersible Powder AT Dispersible GPP-39 (2.5%) + AO5(2%) + Powder AT Only GPP-39 GPP-39 PP+ Blank Only (2.5%) (15.4%) (15.4%) (15.4%) Maximum 69.12 66.31 49.43 44.17 25.28 Load (N) Initial 46.5 45.2 47.2 48.4 26.5 Yield (N)
[0082] The data of Table 9 are shown graphically in FIG. 19.
[0083] There is only a 4% loss in maximum load from blank to dispersible powder AT-only compound, compared to 63% loss for the AO5 compound. The initial yield of the compound increases as the GPP-39 compound is added, with the highest result of all being the Azub™+GPP-39. This increase in initial yield is probably due to a combination of the Wax E acting as a plasticizer, and the positioning of the GPP-39 in the fiber lattice allowing ore initial elongation before the polymer molecules within the fiber begin to straighten.
[0084] Some basic fire testing was carried out on plaited sections of fibers. The basic test involved igniting a suspended fiber for 2×10 seconds with a 1 inch bunsen burner flame and observing the flame behavior (this is similar to the UL-94 test). These results are summarized in Table 10:
TABLE 10 Dispersible Dispersible Powder AT GPP-39 Powder AT AO5 (2%) + Only Only (2.5%) + GPP-39 PP+ Blank (2.5%) (15.4%) GPP-39 (15.4%) (15.4%) Flammability Ignited, Ignited, Ignited, extinguished Flame Characteristics burning burning burning after both extinguished drips drips drips flame through fire applications, dripping away no dripping from the fiber
Example 12
[0085] A flame retardant dispersible powder was made in the same manner as described in Example 1, except that sodium antimonate was used as the flame retardant material and Abril Abriflow 85 powder (Industrial Waxes Limited), an amide based wax, was used as the core material, using the conditions and amounts of Example 1. This material was formulated into PET fibers (Kodapak PET 7352), successfully.
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The present invention is directed to the formation of a solid, dispersible flame retardant powder, by depositing solid flame retardant particles, via electrostatic and packing interactions, onto emulsified droplets of a melted wax, melted polymer, or organic solid carrier, or onto droplets of an organic liquid carrier. Additionally, the invention is directed to the use of such particles as flame retardants in a thermoplastic or the thermosetting polymer composition and coatings.
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CROSS-REFERENCE TO RELATED APPLICATION
The present document is a divisional of U.S. application Ser. No. 11/945,383, filed Nov. 27, 2007, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a directional rotary drilling method and apparatus; specifically, to a method and apparatus for moving a drill bit along a desired path.
2. Related Art
All methods known to applicant use some manner of mechanical contact with the well bore to achieve the desired steering of the drilling tool, or as in the case of point-the-bit methods, the steering is achieved by offsetting the angle of the drill bit axis relative to the rest of the drill tool. Fluid pressure necessary to cause fluid flow through changing flow geometries (orifices, bends, narrow passages, conduits, etc.) commonly described as pressure loss is typically considered a negative effect of changing flow conditions because it often requires alternative design requirements. That same changing fluid flow conditions is used in the described method and apparatus to create a pressure differential between the two sides of the drilling tool and thereby achieve a desired lateral force on the drilling tool useable for steering the tool in the given direction. There have been attempts to use changing directional fluid flows that are different than this invention and not intended to use the hydraulic pressure difference around the drilling tool for steering the tool in the preferred direction. See U.S. Pat. No. 4,836,301 as an example of these types of fluid directing systems, which uses changing direction of drilling fluid flow inside the drilling tool to generate a hydrodynamic force to tilt the drill bit axis in a given direction using a point-the-bit steering method and system.
SUMMARY OF THE INVENTION
Hydraulic steering of a drill bit comprises utilizing a plurality of steering pads to steer a bottom hole assembly. A portion of hydraulic fluid, e.g. drilling fluid, is directed under pressure to a pad interface region proximate each pad. The hydraulic fluid provides additional force against a surrounding wall and/or reduces or eliminates contact between the pads and the surrounding wall.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a schematic diagram of a lateral orifice arrangement located in a drill bit.
FIG. 2 is a schematic diagram of the lateral orifice arrangement located in a bottom hole assembly.
FIG. 3 is a schematic diagram of an adjusting orifice body which moves the distal tip of the orifice closer to a lateral well bore face.
FIG. 4 is a schematic diagram of a point-the-bit rotary steering system using the hydraulic force from the orifice to move fluid against a pivot arm of the bit.
FIG. 5 is a schematic diagram of an orifice arrangement in the body of a directional drilling control pad.
FIG. 6 is a graph describing the expected relation between the annular gap and the lateral hydraulic force at various flow rates.
FIG. 7 is a graph describing the expected relation between the lateral flow rate and the lateral hydraulic force at various gap distances.
DETAILED DESCRIPTION
As shown in FIG. 1 , a method for hydraulic steering of a down hole drilling tool without the mechanical contact of the tool steering section with the bore hole 100 is presented herein. Substantial lateral hydraulic force on a down hole tool can be achieved by the diversion of a portion of a drilling fluid that is forced to flow out on one side of the tool into the relatively small annular gap h between the lateral edge of the tool 10 and the bore hole 100 . As more fully shown in the schematic drawing of FIG. 1 , the pressure differential created this way around the tool/bit 50 in the tool-borehole annulus 110 can produce a large lateral force, depending on the geometry of the flow (the gap width h and length, size of the lateral fluid exit hole, etc.), pressure differential between the inside of the tool and the outside of the tool, fluid properties, and other factors. The lateral force on the tool and/or the bit 50 created this way can be sufficient to provide steering of down hole drilling systems. The hydraulic lateral force can be achieved by using a design that is similar to the current bias or steering unit design, but which has a plurality of lateral orifices 40 (one of which is shown via this cross-sectional view and another is represented via dashed lines), instead of the current pad-piston assembly. The lateral orifice 40 exit area needs to be sufficiently close to the borehole wall or face 100 to ensure a sufficiently small gap h between the lateral edge of the tool body 10 where the side orifice 40 is located and the borehole 100 in order to provide enough pressure differential around the tool in the tool-borehole annulus 110 . The lateral force can also be achieved with lateral orifices 40 placed in the hole gauge 10 next to the drill bit 50 itself, where a smaller gap h between the tool 50 and the borehole 110 is easier to maintain during drilling (the smaller the gap, the bigger the hydraulic side force).
As the entire drilling BHA is rotated during drilling, including the lateral orifices, one or more lateral orifices are open only when they are approximately opposite to the desired change in drilling direction, while all other lateral orifices are closed until they get approximately opposite to the desired change in drilling direction as the entire BHA rotates around its longitudinal axis. The corresponding opening and closing of the lateral orifices, or opening and closing of the drilling fluid paths to these orifices, can be achieved and controlled by using existing methods for opening and closing fluid paths to the steering pads of a traditional bias or steering unit and controlling the process with a traditional control unit that performs necessary measurements and provides control and steering functions. For example, a counter-rotating valve that rotates at the same rotational speed as the drilling BHA but in the opposite direction can be used to open and close the drilling fluid path to the lateral orifices, thus keeping the fluid flow through the lateral orifices geo-stationary, i.e. in the same relative direction/orientation to the earth, while the rest of the drilling BHA rotates relative to the earth. The drilling fluid flow through the lateral orifices is kept geo-stationary in the lateral direction that is opposite to the desired change in drilling direction.
The desired opening and closing of the lateral orifices or the fluid paths to these orifices also can be achieved by other means, such as a piston or valve mechanism controlled from the control unit that measures the relative BHA position and orientation in real time, or by other means.
The described methods and mechanisms can also be used to direct the drilling BHA to drill straight ahead in a straight line along its longitudinal axis. For example, the rotary valve described above can be used to direct the drilling fluid flow to one or more lateral orifices to achieve the desired lateral hydraulic force and the corresponding drill bit movement in the opposite direction. When the rotary valve is not kept geo-stationary but instead it is rotated fully or partially with the rest of the BHA, or partially counter rotated relative to the BHA, the drilling fluid is effectively directed to the lateral orifices while they are in various orientations to the earth, thus applying the lateral hydraulic force in all directions around the bore hole and thus directing the drilling BHA straight ahead along its longitudinal axis. Another way of directing the BHA to drill straight ahead is to open all the lateral orifices at the same time, or to close all lateral orifices while drilling straight and switch back to the steering mode when the BHA starts to deviate from the straight path.
In another embodiment as shown in FIG. 4 , the proposed method can be used to achieve steering of a drilling tool 51 by discharging a portion of the drilling fluid into the tool-borehole annulus on one side of the drilling tool between two integral parts of the down hole tool itself, for example, between the tool inner body 52 and an outer sleeve 53 connected together with a universal joint UJ, where the outer sleeve 53 is connected to the bit shaft 54 , and where an angular offset of the sleeve 53 and the bit axis relative to the tool inner body axis, which provides the desired steering of the bit, is achieved by a similar hydraulic force. By opening the lateral orifices only when they are opposite to the desired change in the drilling direction as the BHA rotates, and by using one of the methods described above for controlling the opening and closing of the lateral orifices, the outer sleeve 53 and the drill bit axis are kept at an angular offset relative to the rest of the BHA, which steers the tool in the direction of the angular offset that is kept geo-stationary in the desired drilling direction.
Current directional drilling systems use a down hole mud motor with a bend sub or a rotary steerable system (RSS) with a steering section to create a 2-D or a 3-D well bore trajectory. RSS systems have many advantages over mud motor systems and are used for most drilling applications today. The current RSS systems use push-the-bit or point-the-bit approaches to achieve the desired steering of the drilling tool.
Most of the today's drilling market is covered by systems using the push the bit technology, which uses mechanical pads 200 , an example of which is partially shown in FIG. 5 , that extend radially from the drilling tool and push against the borehole 100 to achieve a side force on the tool that in turn forces the bit to drill in the same direction of the side force acting on the tool. The principal problem with these pad systems is high wear that results from contacts with the borehole 100 , which results in a high manufacturing and repair cost and therefore an overall higher cost of service delivery. The novel approach proposed herein minimizes mechanical contacts with the bore hole for steering purposes.
Pressure drop test data show that a large pressure differential and thus a large lateral force could be achieved with the currently used pressure difference between the inside and the outside of the drilling tool and with a fraction of the current overall flow rate of the drilling fluid. FIGS. 6 and 7 summarize this relationship.
Steering of the drilling tool or drill bit can be achieved by applying hydraulic forces to one side of the tool, thus achieving the steering of the tool in the opposite direction. The concept of the proposed invention can be explained by using FIG. 2 . A portion of drilling fluid (mud) is diverted through a lateral orifice (Q s ) and into a narrow gap (h) between the tool steering section 11 and the borehole 100 . Only orifices 40 on one side of the tool are opened for the lateral fluid flow (Q s ) at a time to provide a pressure differential between that and the opposite side of the tool (p 1 −p 2 ), thus creating a lateral hydraulic force on the tool and the bit (F s ), which steers the tool and the bit in the opposite direction of the side flow Q s . The pressure differential is achieved principally by the pressure required to push a certain amount of drilling fluid (at fluid flow rate—Q s ) through the tight gap between the tool and the borehole (dimension h in FIG. 2 ). The pressure needed to push the fluid through the narrow tool-borehole gap h is provided by the pressure difference between the inside p o and the outside of the drilling tool p 2 .
In another embodiment, the lateral discharge of portion of the drilling fluid Q s can be forced into an even tighter annular gap h between the bit hole gauge section 10 and the bore hole 100 on an adjacent lateral side of the drill bit 50 as shown in FIG. 1 . In this manner, a higher lateral hydraulic force F s for steering the bit can be achieved with less fluid loss. Also, this system may be less complex because it would eliminate the need for an entirely separate steering section/module of the downhole tool. For example, the flow control mechanism, e.g. a rotary valve, can be part of the control unit, and the lateral orifices used for steering can be part of the drill bit assembly. Traditionally, there is a separate steering section/module, e.g. a bias unit, between the drill bit and the control unit. If the annular gap (h) between the tool 50 in FIG. 1 or 11 in FIG. 2 and the borehole 100 is too large or may change significantly during drilling, a modified orifice body, an example of which is shown in FIG. 3 , can be used to provide a self-adjusting tight annular gap (h). The fluid pressure on the inner end of the adjustable adapter p o would push the adapter 300 radially outwards, reducing the annular gap (h) in the process. When the annular gap h is small enough to produce fluid pressure on the outer end of the adapter 300 (in the gap h) which produces an inward force on the adaptor end that is equal to the outward force on the adaptor from the inner fluid pressure, the adaptor reaches an equilibrium state resulting in an annular gap (h) that can be smaller than those described in the previous examples. The size of the adjustable gap (h) mainly depends on the geometry of the adaptor, geometry of the fluid flow, and the pressure difference between the inside and the outside of the drilling tool. Thus, a desired, self-adjusting annular gap h can be achieved and maintained by carefully specifying and controlling these parameters. When the adapter 300 is not used for steering purposes, and to prevent it from protruding radially out of the BHA too much, a spring, or an elastomer or other means can be used to keep the adapter in its inner-most position inside the BHA, example of which is shown in FIG. 3 . In another embodiment, the proposed method can be used to achieve steering of a drilling tool by discharging a portion of the drilling fluid on one side of the drilling tool between two integral parts of the down hole tool itself, for example, between the tool inner body 52 and an outer sleeve 53 connected together with a universal joint (UJ), as shown in FIG. 4 , where the outer sleeve 53 is connected to the bit shaft 54 , and where an angular offset of the sleeve and the bit axis relative to the tool inner body axis, which provides the desired steering of the bit, is achieved by a similar hydraulic force. The particular design concept in FIG. 4 can be optimized to further restrict the exit of the fluid between the sleeve and the tool inner body to increase the pressure (p 1 ) between the two parts, thus increasing the differential pressure (p 1 −p 2 ) and increasing the hydraulic lateral force F s that is used for steering. The proposed method also can be used with the existing drilling tool designs to minimize the abrasion wear and tool shocks and vibrations as shown in FIG. 5 . A small amount of drilling fluid can be discharged under pressure through the pad 200 at the pad-bore hole interface 210 to produce a hydraulic force F s on the pad and reduce or eliminate the mechanical contact between the pad 200 and the bore hole 100 . Because the gap between the active pad and the bore hole is very small or basically non-existent while the pad is pushing against the bore hole, only a small amount of drilling fluid would need to be discharged to achieve a relatively large hydraulic lateral force between the pad 200 and the borehole 100 and, therefore, minimize or eliminate the mechanical contact between the pad 200 and the borehole 100 .
Estimates of the lateral hydraulic forces associated with the steering method described herein are shown in FIG. 6 and FIG. 7 . The pressure in the annular gap h between the tool and the bore hole used to calculate these lateral hydraulic forces was estimated based on measured pressure drop data when water was pumped through a down hole nozzle with an equivalent overall fluid discharge area (total area of all nozzle orifices). The pressure distribution in the annular gap was assumed to correspond to the measured pressure drop through the down hole nozzle for the same total flow area, i.e. the fluid flow in the annular gap h requires the same pressure to achieve the same flow rate as the fluid flow through the nozzle for the same flow area (total nozzle orifice area). Since the flow area in the annular gap h progressively increases with distance from the lateral orifice, the pressure in the gap was estimated at various radial distances from the lateral orifice and the lateral force was calculated as the sum of products of each discrete pressure and the corresponding tool area. Although these pressure-force estimates are based on test data from a different flow system, they provide an approximation of the pressure distribution in the annular gap h and the lateral hydraulic force F s on the drilling system under consideration.
As can be seen from FIG. 6 and FIG. 7 , lateral hydraulic forces higher than the pad forces of a comparable commercial drilling system, shown as Standard Pad system in FIG. 6 and FIG. 7 , can be achieved for many practical flow rates and annular gaps, which depend on the hole size drilled, among other factors. For the examples in FIG. 6 and FIG. 7 , practical flow rates through the lateral orifices (lateral flow rates) can be on the order of 100 gpm and the practical annular gap h can be on the order of 2 mm, but other lateral flow rates and annular gaps can be practical as well. For example, a tighter annular gap h can be made practical with the method and mechanism shown in FIG. 3 , thus increasing the lateral hydraulic force even further, and reducing the required lateral flow rate for effective steering of the drilling BHA. Additionally, to achieve a higher pressure in the annular gap h and, consequently, higher lateral force F s for hydraulic steering of the drilling tool, the geometry of the annular flow can be changed so that a higher pressure drop is achieved in the annular gap both near and away from the lateral orifice, for the same nominal annular gap h and the same lateral fluid flow rate Q s . For example, the lateral flow can be discharged in the localized annular gap at multiple points in different directions to create a higher pressure drop and a higher pressure in a larger annular gap area, producing a larger lateral force (e.g. multiple lateral flows in the same annular gap would flow against each other, thus possibly creating a higher pressure drop before the fluid exits the annular gap area). Other ways, for example without limitation include changing the flow and tool geometries, fluid properties, and pressure differentials can be substituted for a more optimized hydraulic lateral forces on the drilling tool thereby providing adequate steering with a minimum disruption to the fluid flow through the drill bit.
Numerous embodiments and alternatives thereof have been disclosed. While the above disclosure includes the best mode belief in carrying out the invention as contemplated by the named inventors, not all possible alternatives have been disclosed. For that reason, the scope and limitation of the present invention is not to be restricted to the above disclosure, but is instead to be defined and construed by the appended claims.
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A technique is used to control the direction of a drill bit or bottom hole assembly via hydraulic steering utilizing a plurality of steering pads. A portion of hydraulic fluid, e.g. drilling fluid, is directed under pressure to a pad interface region proximate each pad. The hydraulic fluid provides additional force against a surrounding wall and/or reduces or eliminates contact between the pads and the surrounding wall.
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CROSS REFERENCE TO RELATED APPLICATIONS
(Not Applicable)
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
(Not Applicable)
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to the field of speech systems and more particularly to a method and apparatus for dynamically adjusting audio input gain according to conditions sensed in an audio input signal to a speech system.
2. Description of the Related Art
Speech systems are systems which can receive an analog audio input signal representative of speech and subsequently digitize and process the audio input signal into a digitized speech signal. Speech signals, unlike general audio signals, contain both speech data and silence data. That is, in any given sample of audio data representative of speech, a portion of the signal actually represents speech while other portions of the signal represent background noise and silence. Hence, in performing digital processing on an audio signal, a speech system must be able to differentiate between speech data and background and silence data. Accordingly, speech systems can be sensitive to the quality of an audio input signal in performing this necessary differentiation.
The quality of an audio input signal can be particularly apparent in a handheld, portable speech system. Specifically, users of portable speech systems often provide speech input to the speech system in varying environmental conditions. For example, a user of a portable speech system can dictate speech in car, in an office, at home in front of the television, in a restaurant, or even outside. Consequently, many environmental factors can affect the quality of speech input. When in a car, interior cabin noise can be included in the speech signal. When in an office, a ringing telephone can be included in the speech signal. When outside, the honking of a passing car can be included in the speech signal. As a result, the portion of a speech input which is to be interpreted as speech data can vary depending on what is to be interpreted as background “silence”—car honking, television programming, telephone ringing, interior cabin noise, or true silence.
The problem of speech signal quality in identifying speech data in a speech system can be compounded by the process of speech recognition. Speech recognition is the process of converting an acoustic signal, captured by transducer, for instance a microphone or a telephone, to a set of words. The recognized words can be the final results, as for applications such as commands & control, data entry, and document preparation. They can also serve as the input to further linguistic processing in order to achieve speech understanding. Speech recognition is a difficult problem, largely because of the many sources of variability associated with the signal.
First, the acoustic realizations of phonemes, the smallest sound units of which words are composed, are highly dependent on the context in which they appear. These phonetic variables are exemplified by the acoustic differences of the phoneme /t/ in two, true, and butter in American English. Second, differences in sociolinguistic background, dialect, and vocal tract size and shape can contribute to across-speaker variables. Third, acoustic variables can result from changes in the environment as well as in the position and characteristics of the transducer. Finally, speaker variables can result from changes in the speaker's physical and emotional state, speaking rate, or voice quality.
The speech recognition accuracy of a speech-to-text conversion system depends directly upon the quality of an audio input signal containing the speech data to be converted to text. Specifically, it is desirable for the amplitude of an audio input signal to fall within an optimal range. While the specific limits of the desired range can vary from speech recognition engine to speech recognition engine, all speech recognition engines can experience imperfect speech recognition performance when the amplitude of an audio input signal falls outside of an acceptable range.
Specifically, an audio input signal having an amplitude falling below an extremely low level—an insufficient signal—can cause the degradation of speech recognition performance of a speech recognition engine. Correspondingly, an audio input signal having an amplitude exceeding an extremely high level can result in a saturated signal, a clipping condition as well as signal distortion. An insufficient or excessive audio signal can arise in response to a variety of conditions. For example, when providing speech input to a speech system, the speaker can move either the speaker's head with respect to the microphone or the microphone with respect to the speakers head. Also, the speaker inadvertently can change the volume of the speaker's voice or the input volume controlled by the audio circuitry used to receive the speech input audio signal.
When configuring a speech system, speech systems typically measure the characteristics of an audio input signal for a particular speaker using a particular microphone. Using these measured characteristics, the speech system can set system parameters to optimize the amplification and conditioning of the audio signal. Thus, in the case where different speakers provide audio input to the same speech system at different times, the speech system parameters can prove inadequate to accommodate the subsequent speaker for which the parameters had not been optimized. Likewise, in the case where different microphones are used at different times to provide speech audio input to the same speech system, the speech system parameters can prove inadequate to accommodate the second microphone for which the parameters had not been optimized. As a result, in either case, an insufficient or excessive audio signal condition can arise.
Present speech systems have yet to adequately address the problem of varying amplitudes of speech audio input signals. Specifically, what is needed is a method for monitoring the amplitude of a speech audio input signal during a speech session and adjusting the amplitude of the speech audio input signal accordingly. Hence, there exists a present need for dynamically adjusting audio input gain in a speech system.
SUMMARY OF THE INVENTION
A method for adjusting audio input signal gain in a speech system can include seven steps. First, an upper and a lower threshold can be predetermined in which the upper and lower threshold define an optimal range of audio data signal amplitude measurements. Second, a frame of unpredicted digital audio data samples can be received. In particular, the unpredicted digital audio data samples can be acquired by audio circuitry in a computer system. Significantly, the digital audio data samples received are not pre-scripted and are unknown to the computer system at the time of reception with regard to speech content.
Each sample can indicate an amplitude measurement of the audio data signal at a particular point in time. As such, third, a maximum signal amplitude can be calculated for a configurable measurement percentile of the unpredicted digital audio data samples. A measurement percentile is a selected percentage of samples in the digital audio data upon which computations are to be performed. For example, the calculation of the maximum signal amplitude for the ninety-eighth (98th) measurement percentile means the maximum signal amplitude for the first ninety-eight (98) percent of all samples in the frame.
Subsequent to the calculation of the maximum signal amplitude for the configured measurement percentile, fourth, the audio input signal gain can be incrementally adjusted downward if the maximum signal amplitude exceeds the upper threshold. Conversely, fifth, the audio input signal gain can be incrementally adjusted upward if the maximum signal amplitude falls below the lower threshold. Sixth, additional frames of unpredicted digital audio data samples can be received. Finally, seventh, each of the third through the sixth steps can be repeated with the received additional frames until the calculated maximum signal amplitude falls within the optimal range of audio signal amplitude.
In the one embodiment, in addition to the upper and lower thresholds, a full scale threshold can be predetermined above which a clipping condition is considered to have occurred. A clipping condition can be detected by first calculating a maximum signal amplitude for the digital audio data samples in the received frame. If the calculated maximum signal amplitude exceeds the full scale threshold, a downward adjustment can be calculated if necessary to bring the maximum signal amplitude within the optimal range. Subsequently, the audio input signal gain can be adjusted downward by the calculated downward adjustment. A clipping condition can also be determined by calculating a hypothetical signal peak amplitude. If the calculated hypothetical signal peak amplitude exceeds the full scale threshold, again, a downward adjustment can be calculated and performed if necessary to bring the hypothetical peak amplitude within the optimal range.
Notably, in another embodiment, a silence threshold can be calculated below which a quantity of digital audio data samples are interpreted as silence samples and above which a quantity of digital audio data samples are interpreted as speech samples. As a result of the calculation of a silence threshold, signal gain adjustments can occur only if the calculated maximum signal amplitude exceeds the silence threshold. Furthermore, in yet another embodiment, a silence timeout condition can be detected, the silence timeout condition occurring when no silence samples are received in a predetermined number of received frames. Responsive to detecting the silence timeout condition, the silence threshold can be increased by a proportional factor. Also, upon receiving an unpredicted frame of digital audio data samples having a maximum signal amplitude below the silence threshold, where as a result, the frame of digital audio data samples are interpreted as a frame of silence samples, a new silence threshold can be calculated based upon the maximum amplitude measurements of previously received silence samples. The new silence threshold can be calculated by first, storing a data set of previously received frames of silence samples, second, averaging the maximum amplitudes for each stored from in the data set, and, third, multiplying the average by a proportional factor.
Notably, two conditions can exist which have a bearing upon the calculation of a silence threshold in response to receiving silence samples in a frame. First, a clipping condition can exist in which samples exceeding the full scale threshold have been detected. Second, an initial condition can exist in which an adequate number of silence samples have yet been received in order to properly set the silence threshold. In either circumstance, a new silence threshold can be calculated based upon a maximum amplitude measurements of a second configurable measurement percentile of previously received speech samples. Specifically, the step of calculating a new silence threshold based upon maximum amplitude measurements of previously received speech samples can include storing a data set of previously received frames of speech samples and identifying a maximum amplitude for the second configurable measurement percentile of speech samples in each stored frame in the data set.
Significantly, the present invention can include histogram analysis techniques to identify whether the upper, lower and full scale thresholds have been breached. As a result, in a preferred embodiment of the present invention, an audio data histogram can be established. The audio data histogram can include a plurality of bins, each bin associated with a range of amplitude measurements and each bin having a corresponding counter. Each corresponding counter can be incremented in response to receiving a digital audio data sample having an amplitude measurement falling within an amplitude range associated with the corresponding bin. Thus, in response to receiving a digital audio data sample having an amplitude measurement falling within an amplitude range associated with a bin in the histogram, the counter associated with the bin can be incremented. Furthermore, the incrementing step can be repeated for each digital audio data sample in the frame, the repeating step populating the audio data histogram with histogram data derived from amplitude measurements of the digital audio data samples.
The audio data histogram can be used in the adjusting steps of the preferred embodiment. Specifically, the step of incrementally adjusting downward can include first specifying a measurement percentile of digital audio data samples in the histogram upon which an adjustment is determined. Second, a cumulative sum of counters in the histogram can be obtained. Specifically, the summation can begin with the zero-th bin in the histogram and can continue until reaching the i-th bin below which the cumulative sum, When compared to all samples in the histogram, corresponds to the specified measurement percentile. Third, a maximum signal amplitude corresponding to samples in the i-th bin can be calculated. The calculation can be based upon only those samples in the i-th bin which are included in the specified measurement percentile of digital audio data samples. Finally, fourth, the audio input signal gain can be incrementally adjusted downward if the calculated maximum signal amplitude corresponding to the samples in the i-th bin exceeds the upper threshold.
Similarly, the step of incrementally adjusting upward the audio input signal gain can include first specifying a measurement percentile of digital audio data samples in the histogram upon which an adjustment is determined. Second, a cumulative sum of counters in the histogram can be obtained. Specifically, the summation can begin with the zero-th bin in the histogram and can continue until reaching the i-th bin below which the cumulative sum, when compared to all samples in the histogram, corresponds to the specified measurement percentile. Third, a maximum signal amplitude corresponding to samples in the i-th bin can be calculated. The calculation can be based upon only those samples in the i-th bin which are included in the specified measurement percentile of digital audio data samples. Finally, fourth, the audio input signal gain can be incrementally adjusted upward if the calculated maximum signal amplitude corresponding to the samples in the i-th bin falls below the lower threshold.
Preferably, a data set of audio data histograms can be stored upon which histogram computations can be performed. Advantageously, by basing histogram computations on an average of histogram computations for all histograms in a data set, anomalous measurements can be diluted. In consequence, it can be determined if the data set has been populated with audio data histograms prior to the gain adjusting steps. If it is determined that the data set has not been populated, the gain adjusting steps preferably are not performed. Moreover, all audio data histograms in the data set can be discarded responsive to an audio gain adjustment.
In yet another embodiment, a silence data histogram can be incorporated. Like the audio data histogram, the silence data histogram can include a plurality of bins, each bin associated with a range of amplitude measurements and each bin having a corresponding counter. The corresponding counter can be incremented in response to receiving a silence sample having an amplitude measurement falling within an amplitude range associated with the corresponding bin. Furthermore, in response to receiving a silence sample having an amplitude measurement falling within an amplitude range associated with a bin in the histogram, the counter associated with the bin can be incremented. The incrementing step can be repeated for each silence sample in the frame, the repeating step populating the silence data histogram with histogram data derived from amplitude measurements of the silence samples.
Advantageously, the silence data histogram can be used in the step of calculating a new silence threshold. In that case, the calculating step can include storing a silence data set of silence data histograms and averaging maximum amplitudes for each histogram in the silence data set. Finally, the average can be multiplied by a proportional factor. The resulting value can be the new silence data threshold. As in the case of the data set of audio data histograms, however, it can be determined if the silence data set has been populated with silence data histograms prior to the silence threshold calculating step. If it is determined that the silence data set has not been populated, the silence threshold calculating step preferably is not performed. Moreover, all silence data histograms in the silence data set can be discarded in response to either an audio gain adjustment or the calculation of a new silence threshold.
BRIEF DESCRIPTION OF THE DRAWINGS
There are presently shown in the drawings embodiments which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
FIG. 1 is a pictorial representation of a computer system configured for use with the present invention.
FIG. 2 is a schematic diagram of a computer system architecture implemented in the computer system of FIG. 1 and configured for use with the present invention.
FIGS. 3A-3D, taken together, are a flow chart illustrating a method for adjusting audio input gain according to conditions sensed in an audio input signal to a speech recognition system.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is a method for adjusting audio input gain according to conditions sensed in an audio input signal to a speech system. The method can be incorporated in a computer program, referred to as an Audio Optimizer, which can execute in a computer system and monitor an audio input signal received in computer system audio circuitry. The Audio Optimizer can adjust the audio input gain of the audio circuitry according to various thresholds required by the speech system also executing in the computer system in order to maintain an average amplitude of the audio input signal within a specified optimal range.
FIG. 1 is a schematic diagram illustrating a computer system 1 configured for use with the present invention. The computer system 1 is preferably comprised of a computer including a central processing unit (CPU) 2 , one or more volatile and non-volatile memory devices 3 , 4 and associated circuitry. The volatile memory devices 3 , 4 , preferably are comprised of an electronic random access memory 3 and a bulk data storage medium 4 , such as flash memory or a magnetic disk drive. The computer system can include an input transducer 6 , for example a microphone, as well as an audio output device 7 , for example speakers, both which are operatively connected to the computer system 1 through suitable audio circuitry 5 also referred to as a “sound board”. Additionally, the computer system 1 can include a keyboard input device 8 , a pointing device, for instance a mouse (not shown), and at least one user interface display unit 9 such as a video data terminal (VDT), each operatively connected to the computer system 1 . Still, neither the VDT 9 , keyboard 8 , mouse, nor the speakers 7 , are necessary for operation of the invention as described herein. In fact, in the preferred embodiment, the computer system 1 is an embedded computer system suitable for use in a portable device, for example a cellular phone, a personal digital assistant or a vehicle navigation system. Such embedded systems are well-known in the art and are embodied in such embedded platforms as the Workpad® manufactured by International Business Machines Corporation. Notwithstanding, the various hardware requirements for the computer system as described herein also can generally be satisfied by any one of many commercially available high speed multimedia personal computers such as those offered and manufactured by International Business Machines Corporation.
FIG. 2 illustrates a typical architecture for a computer system configured to dynamically adjust audio input gain according to conditions sensed in an audio input signal to a speech system executing in the computer system 1 of FIG. 1 . In the preferred embodiment, the speech system can include a speech recognition capability for converting speech input into recognized text. Still, the invention is not intended to be so limited. Rather, it is intended that the present invention solve the problem of maintaining analog audio input signal quality in any speech system, regardless of whether such speech system also performs speech-to-text conversion of the audio input signal.
In the preferred embodiment, however, as shown in FIG. 2, the computer system 1 typically includes an operating system 18 and a Speech Recognition Engine 22 . In the example shown, an Audio Gain Optimizer 24 and an Audio Circuitry Device Driver 26 are also provided. In FIG. 2, the Speech Recognition Engine 22 , Audio Gain Optimizer 24 , and the Audio Circuitry Device Driver 26 are shown as separate application programs. It should be noted however that the invention is not limited in this regard, and these various application programs could be implemented as a single, more complex applications program. For example the Audio Gain Optimizer 24 could be combined with the Audio Circuitry Device Driver 26 or with any other application to be used in conjunction with the Speech Recognition Engine 22 . Notwithstanding, in the preferred embodiment, the Audio Gain Optimizer 24 exists without combination in a software layer between the operating system and the Speech Recognition Engine 22 .
In a preferred embodiment which shall be discussed herein, operating system 24 is an embedded operating system, such as QNX Neutrino® or Wind River System's VxWorks®. However, the system is not limited in this regard, and the invention can also be used with any other type of computer operating system, for example WindowsCE® or WindowsNT®. The operating system 18 can be stored in the fixed storage 4 of the computer system 1 along with the Speech Recognition Engine 22 , the Audio Gain Optimizer 24 and the Audio Circuitry Device Driver 26 . Upon bootstrap, the computer system 1 , using bootstrap techniques well-known in the art, can load the operating system 18 into random access memory 3 . Subsequently, the computer system 1 can cause the execution of the operating system 18 .
The Audio Circuitry Device Driver 26 can load and execute concurrently with the operating system as is the case with typical device drivers. The Audio Circuitry Device Driver 26 , like typical device drivers, can provide a software interface between the operating system and hardware circuitry, known in the art as a device, so that the operating system can control the device and can communicate data to and from the device. Notably, the Audio Circuitry Device Driver 26 , like typical device drivers, can expose various methods contained in the software for manipulating and communicating with the audio circuitry 5 . Notably, included among the exposed methods are methods for reading data from an incoming stream of digitized audio data, and methods for setting the audio input gain in the pre-amplifier contained in the audio circuitry 5 . Hence, a method for adjusting audio input gain according to conditions sensed in an audio input signal to the Speech Recognition Engine 22 , as embodied in the Audio Gain Optimizer 24 , can monitor an audio input signal received in the audio circuitry 5 and can manipulate the audio input gain of the audio circuitry 5 , both using the exposed methods of the Audio Circuitry Device driver 26 .
The Audio Gain Optimizer 24 can implement a method for adjusting audio input gain according to conditions sensed in an audio input signal to the Speech Recognition Engine 22 . Specifically, subsequent to loading and executing the operating system 18 and corresponding device drivers, including the Audio Circuitry Device Driver 26 , a user can load and execute the Speech Recognition Engine 22 included as part of a speech recognition system. Notably, the Audio Gain Optimizer 24 can be included as part of either the Speech Recognition Engine 22 or the Audio Circuitry Device Driver 26 . However, in the preferred embodiment, the Audio Gain Optimizer 24 stands alone. As such, the Audio Gain Optimizer 24 is further loaded and executed along with the Speech Recognition Engine 22 .
When a speaker speaks into the transducer 6 , the resulting electrical analog signal can be passed to the audio circuitry 5 in the computer system 1 . The audio circuitry 5 , as is the case with typical sound boards known in the art, can process the analog signal in a pre-amplifier stage prior to passing the processed signal to a CODEC and an A/D Converter stage for ultimate digitizing of the analog audio signal. The digital form of the audio signal preferably can be represented in pulse code modulation (PCM) format. PCM format consists of a series of binary-coded numbers, each representing the sampled value of the analog signal at a specific time point. The sampling rate for acquiring the digital data can be the industry standard 44.1 kilosamples per second, although in the preferred embodiment, the sampling rate can be 11.025 kilosamples per second.
The resulting digital audio signal can be supplied to the Audio Circuitry Device Driver 26 which can pass the digital signal to the operating system 18 . The operating system 18 , in turn, can pass the digital signal to the Audio Gain Optimizer 24 . The Audio Gain Optimizer 24 can measure the signal amplitude of the incoming digital signal and compare the measured amplitude with stored amplitude thresholds. Depending upon the threshold range within which the average amplitude falls, the Audio Gain Optimizer 24 can adjust the audio input gain of the audio circuitry using the exposed methods of the Audio Circuitry Device Driver 26 . Finally, either subsequently or concurrently, the Audio Gain Optimizer 24 can pass the digital audio signal to the Speech Recognition Engine 22 for processing. Ultimately, the Speech Recognition Engine 22 can perform speech-to-text conversion of the digital audio data and provide the text result to a speech-enabled application, for example a dictation client. Still, the invention is not so limited by the performance of speech-to-text conversion of the audio input signal. Rather, the present invention relates to the dynamic adjustment of audio signal gain responsive the measured conditions of the audio input signal.
FIGS. 3A-3D, taken together, are a flow chart illustrating a method for adjusting audio input gain according to conditions sensed in an audio input signal to a speech recognition system. The method as disclosed herein can be implemented in software and embodied in the Audio Gain Optimizer 24 . The flow chart depicts the actions performed by the Audio Gain Optimizer 24 in response to receiving digital audio signal data from the audio circuitry 5 via the Audio Circuitry Device Driver 26 . The software can be implemented by a programmer, using commercially available development tools for the operating systems described above, for example C or C++.
In order to properly monitor and analyze a digital audio signal, first it is preferable to generate a histogram of PCM values. The histogram can be used to generate diagnostic percentiles which, correspondingly, can be used to determine both the necessity and magnitude of an audio gain adjustment. More particularly, during the execution of the Audio Gain Optimizer 24 , both an audio data histogram and a silence data histogram can be constructed and maintained which tracks the frequency of amplitude measurements in particular amplitude ranges based upon a static signal gain setting. The measured audio signal data frequency (and correspondingly, the silence signal data frequency) can be used subsequently to determine both the initial setting of thresholds, more fully discussed below, and subsequent incremental changes in the signal gain. When the signal gain changes, however, the histograms become invalid and, in consequence, need be discarded.
U.S. Pat. No. 5,822,718 issued on Oct. 13, 1998 to Bakis et al. for DEVICE AND METHOD FOR PERFORMING DIAGNOSTICS ON A MICROPHONE, incorporated herein by reference, teaches a preferred method of collecting digital audio data and generating a histogram for analyzing audio characteristics of an audio signal. Initially, a frame of digital audio data can be read from the buffers of the audio circuitry 5 . A typical frame can represent a {fraction (1/10)} second of digital audio data. The amplitude of the digital audio data contained in the frame can be a two-byte value encoded in PCM format and can range from 0 to 32,767 for each sample in the frame. As disclosed in the Bakis specification, first dc bias current can be removed using the formula y i =|x i −b| where y i is the bias-corrected signal amplitude of the i-th sample and b is the dc bias defined as b = 1 N ∑ i = 1 N x i
where x i is the PCM signal value at the i-th sample and N is the total number of samples in the frame.
Each bias corrected sample y i subsequently can be assigned to “bins” in a histogram. To determine the sizes of the bins, the program 12 first, the largest and smallest sample values of y can be identified and labeled y max and y min . The difference between y max and y min can be defined as the range and can be divided into some number M of equal bins. In the preferred embodiment, M=100. Hence, the width of each bin in the preferred embodiment is w = y max - y min M + ɛ
where w is the width and ε is added to the width of the bin to ensure that the total range covered by all the bins is sufficient despite possible rounding errors. In the preferred embodiment, all computations are performed using integers. Accordingly, ε=1 is used.
For each bin, an upper and lower boundary of the bin can be calculated in order to determine a range of sample values represented therein. The lower boundary can be calculated according to the formula I j =y min +(j−1)w where I j is the lower boundary for the j-th bin. Correspondingly, the upper boundary can be calculated according to the formula u j −y min +jw where u j is the upper boundary for the j-th bin. As a result, for each dc bias-corrected sample y i calculated in the Audio Optimizer 26 , a corresponding bin number j i can be computed according to the formula j i = 1 + y i - y min w .
Notably, j i can be rounded down to the nearest integer. Thus, j i always has an integer value.
Each bin can have associated therewith a counter. The Audio Gain Optimizer 26 can process each sample in the frame and can compute a corresponding bin number. For each sample computed to correspond to the j-th bin, the associated counter can be incremented. As a result, each counter indicates the number of samples (count) having an amplitude falling within the range defined by the associated bin. The resulting collection of counts is the histogram. From the histogram, measurement percentiles can be calculated as follows: c j =c j−1+n j where n j is the value of the counter in the j-th bin and c 1 =n 1 .
Accordingly, to determine the PCM value corresponding to the p-th percentile in the histogram, the Audio Gain Optimizer 26 can calculate the number of sample values falling below that percentile using the equation L p = pc M 100
where L is the number of sample values falling below the percentile p and c M is the cumulative number of counts in the list bin. Notably, L p is the cumulative number of counts in the last bin. Hence, L p is the total number of samples represented by the histogram. L p , however, may be smaller than the total number of samples measured in the frame, N, because some samples from the signal are omitted to avoid noise transients, etc. Subsequently, the Audio Gain Optimizer 26 can identify a bin where the cumulative number of counts therebelow is exactly L p . If the Audio Gain Optimizer 26 cannot find a bin having this exact match, a bin can be selected such that the lower bound falls below L p and upper bound is above L p . In that circumstance, the PCM value can be estimated by linear interpolation.
Preferably, the Audio Gain Optimizer 24 can store several histograms in a FIFO list of histograms known as a histogram data set. In the preferred embodiment, the ten most recent histograms of audio speech data and the ten most recent histograms of silence data are stored in two separate data sets. Once the data set has been populated with histograms, a subsequently added histogram can be inserted at the head of the list and the least recently used histogram can be discarded from the tail of the list.
Significantly, the Audio Gain Optimizer 24 includes a table of configurable thresholds, each configured threshold corresponding to a specific amplitude beyond which necessity for an adjustment to the audio gain can be specified. In the preferred embodiment, the table of threshold can be as follows:
Threshold Name
Definition
Action
Full Scale
Maximum Signal Amplitude
Adjust Gain
(FST)
Downward
Upper Change
Exceeds Optimal Range
Minimal Adjust
(UCT)
Gain Downward
(if necessary)
Upper Target
Optimal Range Upper Boundary
No Action
(UTT)
Lower Target
Optimal Range Lower Boundary
No Action
(LTT)
Lower Change
Falls Short of Optimal Range
Minimal Adjust
(LCT)
Gain Upward
(if necessary)
Silence (ST)
Minimum Speech Input Level
No Action
Minimum (MT)
Minimum Signal Level
No Action
The FST corresponds to the maximum allowable signal amplitude. Any signal having an average amplitude which exceeds the corresponding FST is considered a clipping condition and will result in the gain being adjusted downward. Any signal having an average amplitude which exceeds the corresponding UCT, but falls below the corresponding FST, is considered to have exceeded the optimal range, but not to have triggered a clipping condition. As a result, only a minimal downward gain adjustment may be warranted. Any signal having an average amplitude falling between the threshold defined by the UTT and the LTT is considered to fall within an optimal range. As such, no gain adjustment is warranted. The ST is the minimum speech input level. Below the ST, the signal is considered silence and no gain adjustments are made. Additionally, the MT is the minimum signal level. The MT can accommodate sound cards that cannot inherently provide a zero-signal level. Finally, similar to the UCT, any signal having an average amplitude which falls below a corresponding LCT, but exceeding the ST is considered to have fallen below the optimal range, but not to have fallen so below as to be considered silence data. As a result, only a minimal upward gain adjustment may be warranted.
The table below illustrates preferred thresholds for use in the present invention. Notably, in the preferred embodiment, the digitized amplitude associated with a particular threshold is stored in a two byte variable. Hence, the digitized amplitude can be stored in the variable can range from 1 to 32,768. Additionally, for the purpose of simplicity, the digitized amplitude is provided relative to a peak amplitude of 100%. Notwithstanding, in the preferred embodiment, the digitized amplitude thresholds are scaled in accordance with a configurable measurement percentile, for instance 98%.
Threshold
Digitized Amplitude
DBFS
Relative to Target
FST
32K
0 dB
+6 dBr
UCT
22K
−3.3 dB
+2.8 dBr
UTT
17K
−5.5 dB
+0.5 dBr
LTT
15K
−6.6 dB
−0.6 dBr
LCT
12K
−8.5 dB
−2.5 dBr
ST
2K
−24 dB
−18 dBr
MT
1 count
−90 dB
−84 dBr
Turning now to FIG. 3A, the method begins in step 100 in which samples of digital audio data in an acquired frame of digital audio data can be used to populate a histogram which can subsequently be examined for a clipping condition. A clipping condition can occur when the maximum signal amplitude of a portion of an audio input signal exceeds a pre-determined clipping threshold also referred to as the “Full Scale Threshold” (FST). In the preferred embodiment, if three times the interpolated maximum signal amplitude of the ninety-fifth (95th) percentile exceeds the present FST threshold, a clipping condition can be identified. Alternatively, if the maximum signal amplitude of the one-hundredth (100th) percentile of the samples in the acquired frame exceeds the preset FST threshold, a clipping condition can be identified. Notably, the maximum signal amplitude of the 100th percentile can be tracked simply by storing the measured maximum signal amplitude of the digital audio data in each frame. The stored amplitude can be updated upon reading each sample in the frame of digital audio data. In consequence, the maximum amplitude can be observed at any time simply by examining the stored maximum amplitude.
When a clipping condition occurs, the Audio Gain Optimizer 24 can adjust the signal gain downward in a more dramatic fashion than when the amplitude of the digital audio signal is merely out of optimal range. In particular, in step 101 a clipping calculation can be performed in which an estimated PCM value can be computed for the clipped signal based on the PCM value for the FST. The level of downward gain adjustment can be determined in order to bring the PCM value into the optimal range and can be based upon the result of a clipping calculation.
The clipping calculation can be performed in at least two ways. First, in the case in which three times the maximum signal amplitude of the 95th measurement percentile exceeds the maximum signal amplitude of the 100th percentile, the clipping calculation can determine that the value represented by three times the maximum signal amplitude of the 95th measurement percentile represents a hypothetical signal peak which could be measured in the absence of a clipping condition. Alternatively, the maximum signal amplitude of the 100th percentile can be the hypothetical signal peak. In the preferred embodiment, the clipping calculation chosen is based on the higher of three times the maximum signal amplitude of the 95th percentile and the maximum signal amplitude in the 100th percentile. Subsequently, a downward adjustment corresponding to the hypothetical signal peak can be referenced in an overdrive table containing downward signal gain adjustments based upon pre-collected empirical signal data. In the overdrive table, each hypothetical signal peak corresponds to a pre-determined downward audio signal gain adjustment. Subsequently, in step 102 , the audio signal gain can be adjusted downwardly by the amount specified in the overdrive table. More particularly, an exposed method in the Audio Circuitry Device Driver 26 can be invoked for reducing the signal gain. After the downward adjustment, in step 103 , the ST can be reset to zero (0) counts. Additionally, the audio data histograms can be discarded.
In the preferred embodiment, in addition to the audio data histogram, the Audio Gain Optimizer 24 further can store the internal status of the Audio Gain Optimizer 24 . Specifically, the Audio Gain Optimizer 24 tracks the latest condition as a function of the threshold range in which the most recent amplitude average falls, as well as the resulting action performed, if any. For instance, if the most recent signal average exceeds the FST, the internal status will be set to a clipping condition. Furthermore, the resulting reduction in the signal gain will also be recorded in the internal status. Notably, the internal status can be exposed to a user of the Audio Gain Optimizer 24 through an application programming interface to the same. Consequently, in step 109 , upon adjusting the signal gain in response to a clipping condition, the internal status of the Audio Gain Optimizer 24 can be updated and the next frame of data can be read.
Returning to step 100 , if a clipping condition is not detected, in step 104 the maximum signal amplitude of a portion of the audio data as represented in the histogram is determined. Experimentally, it is preferred that the maximum signal amplitude of the ninety-eighth (98th) percentile of the audio data signal is measured. The selection of the 98th percentile is known as the Measurement Percentile (hereinafter “MP”). Still, the present invention is not so limited by the selection of a particular MP. Rather, any suitable MP can be selected according to system requirements and the signal characteristics of an audio data signal subject to the method of the present invention.
In step 104 , an interpolated maximum signal amplitude of the selected MP can be examined in order to detect a silence condition. In order to interpolate the maximum signal amplitude of a portion of the audio input signal, first a bin in the audio data histogram is identified in below which the designated portion of all digital audio samples resides. Subsequently, the maximum signal amplitude can be interpolated based upon the number of samples in the bin, the signal amplitude of the lower boundary of the bin and the upper boundary of the bin.
A silence condition can be detected when the maximum signal amplitude of the selected MP falls below the ST. If a silence condition is detected, in step 105 the histogram can be inserted a data set of silence data histograms. Notably, the silence data histogram can be similar to an audio data histogram in as much as the silence data histogram can indicate the frequency of measurement of audio signals interpreted as silence having a particular amplitude based upon a static signal gain setting. The silence data histogram data set can be used to subsequently set the ST.
However, the ST can not be calculated based upon the silence data histogram until enough silence data histograms been inserted into the silence data histogram data set in order to dilute the effects of anomalous signal amplitude measurements. Preferably, ten frames or one (1) second of measured audio data is adequate for populating a FIFO list of audio data histograms and ten (10) frames or one (1) second of measured silence is adequate for populating the list of silence data histograms. Hence in step 106 , if enough silence data has not been collected, the method branches to step 109 in which the internal status can be updated and the next frame can be read.
Returning to step 106 , if a satisfactory number of silence data histograms have been inserted into the silence data histogram data set, the method branches through jump circle F to step 300 in FIG. 3 B. FIG. 3B illustrates the process for adjusting the ST. In the preferred embodiment, the ST is recalculated dynamically during run-time. It is assumed that if there is no silence observed for a pre-determined period of time, preferably one (1) second, then a silence time-out has occurred in which the ST has been set too low, causing silence to be misinterpreted as speech. In such a situation, the ST is increased. Likewise, the Audio Gain Optimizer 26 can distinguish between background noise and speech data. In situations where the ST is set lower than the background noise level, the ST can be increased so that the ST is at a higher level than the background noise level.
The above-identified process is illustrated beginning in step 300 , in which it is determined if the ST has been set to zero (0) counts indicating either an initial condition or a clipping condition. If the ST has been set to zero (0) counts, in step 302 it is determined if the audio data histogram data set has been sufficiently populated to calculate a new ST. If the audio data histogram set has been sufficiently populated with audio data histograms, so that background noise can be distinguished from the audio signal, in step 307 , a new ST is calculated based on the level of background noise so that the ST is above the background noise level. In the preferred embodiment, the ST is calculated based on the average of interpolated maximum signal amplitude measurements of the twenty-fifth (25th) percentiles of each audio data histogram in the audio data histogram data set. Otherwise, no adjustment of the ST occurs. In either case, returning through jump circle G to step 108 in FIG. 3A, the silence data histograms can be discarded. Subsequently, in step 109 the internal status can be updated and the next frame can be read.
Returning now to step 300 in FIG. 3B, if the ST has not been set to zero (0) counts, indicating a run-time condition and not an initial condition or a clipping condition, in step 301 it is determined if a silence time-out condition has arisen. Specifically, in the preferred embodiment, if silence data has not been detected for a pre-determined period of time, for example 10 (10) frames, it is assumed that the ST has been set too low causing silence data to be misinterpreted as speech data. Accordingly, in step 304 , the ST is increased by a proportional factor, preferably 1.5. Notably, the ST preferably cannot be increased beyond a maximum ST, which in the preferred embodiment can be set at 6,000 counts of amplitude. Otherwise, if a silence time-out has not occurred, a new ST can be calculated based upon the silence data histogram data set.
In step 305 , the new ST can be proportionally based on the average maximum signal amplitudes for the 100th percentile. In the preferred embodiment, the ST is based on three times the average maximum signal amplitude for the 100th percentile of each silence data histogram in the silence data histogram data set. In any event, subsequent to either step 305 or step 304 , in step 306 , the silence data histograms can be discarded to accommodate the new ST. Furthermore, returning through jump circle G to step 108 in FIG. 3A, the silence data histograms can be discarded. Subsequently, in step 109 the internal status can be updated and the next frame can be read.
Returning now to FIG. 3A, if in step 104 , the measured audio data is interpreted not as silence, but as speech, continuing to FIG. 3 C through jump circle 2 , in step 200 , the audio histogram can be appropriately added to the audio data histogram in accordance with the algorithm discussed above. Subsequently, in step 201 , it is determined if the audio data histogram data set has been sufficiently populated with audio data histograms. If it is determined that not enough audio data histograms have been accumulated in the audio data histogram data set so that an effective gain adjustment cannot be calculated based thereon, in step 206 , the internal status is recorded and the next frame of audio data can be read. Otherwise, leading through jump circle D to step 401 of FIG. 3D, it is determined whether the gain direction had been previously set as a result of measured samples either exceeding the UCT or falling below the LCT.
If the gain direction had not been previously set, in step 403 , it is determined whether the maximum signal amplitude of the MP exceeds the UCT. If so, in step 404 , the gain direction parameter can be set to “Down”. Additionally, in step 411 , a global gain variable can be set to indicate a need to decrease the gain. In step 403 , if the maximum signal amplitude of the MP is not greater than the UCT, it is determined in step 405 if the maximum signal amplitude of the MP is less than or equal to the LCT. If so, in step 406 , the gain direction can be set to “Up”. Additionally, in step 412 , a global gain variable can be set to indicate a need to increase the gain. Notably, if the maximum signal amplitude of the MP is neither above the UCT nor below the LCT, the signal amplitude of the digital audio signal is assumed to be in the optimal range. Accordingly, no further actions are necessary.
Returning to step 401 , if the gain direction had been set, indicating that the maximum signal amplitude of the MP had fallen in a range equal to or greater than the UTT, or less than or equal to the LTT, in step 402 , the gain direction can be determined. If the gain direction had been set to “Up”, in step 407 , it is further determined if the maximum signal amplitude of the MP is less than or equal to the LTT. If the maximum signal amplitude of the MP is less than or equal to the LTT, in step 410 a global gain variable can be set to indicate a need to increase the gain. Otherwise, in step 413 it is determined that the maximum signal amplitude of the MP is within the optimal range. As such, the gain direction is reset.
Returning to step 402 , if the gain direction had been set to “Down”, in step 408 , it is further determined if the maximum signal amplitude of the MP is greater than or equal to the UTT. If the maximum signal amplitude of the MP is greater than or equal to the UTT, in step 409 a global gain variable can be set to indicate a need to decrease the gain. Otherwise, in step 414 it is determined that the maximum signal amplitude of the MP is within the optimal range. As such, the gain direction is reset. Regardless, in all cases as initially determined in step 401 , the method returns to step 203 in FIG. 3 C through the jump circle E.
Turning now to FIG. 3C, in step 203 , the global variable for indicating a need to adjust the gain is examined. If a gain adjustment is indicated in the global variable, in step 204 , the gain can be adjusted in the direction indicated by the gain direction by a small percentage of the available range, typically one or two percent. One skilled in the art will observe, however, that the invention is not limited in this regard. Notably, each sound card is different in that a command to increase or decrease gain can cause the same with varying results. A single bit increase in gain in one sound card can result in an increase in audio gain which can differ from the same single bit increase in gain in another sound card. Thus, the gain can be adjusted according to any suitable adjustment scheme, for example by a predetermined adjustment quantity stored in a table and mapped to observed conditions and sound card type.
Subsequent to the gain adjustment step, in step 205 , the audio data histograms in the data set can be discarded. Furthermore, regardless of whether an audio gain adjustment has occurred, in step 206 , the internal status can be updated and new frame can be read in from the audio circuitry.
The Audio Gain Optimizer 26 can effectively monitor frames of audio data containing both speech and silence data in order to determine an optimal audio gain setting for particular audio circuitry. Advantageously, the Audio Gain Optimizer perform such modifications to the audio gain dynamically according to changing audio conditions. Hence, the Audio Gain Optimizer 26 effectively addresses the problem of varying amplitudes of speech audio input signals.
While the foregoing specification illustrates and describes the preferred embodiments of this invention, it is to be understood that the invention is not limited to the precise construction herein disclosed. The invention can be embodied in other specific forms without departing from the spirit or essential attributes. Accordingly, reference should be made to the following claims, rather than to the foregoing specification, as indicating the scope of the invention.
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A method for adjusting audio input signal gain in a speech system can include seven steps. First, an upper and a lower threshold can be predetermined in which the upper and lower threshold define an optimal range of audio data signal amplitude measurements. Second, a frame of unpredicted digital audio data samples can be received. Each sample can indicate an amplitude measurement of the audio data signal at a particular point in time. Third, a maximum signal amplitude can be calculated for a configurable measurement percentile of the unpredicted digital audio data samples. Fourth, the audio input signal gain can be incrementally adjusted downward if the maximum signal amplitude exceeds the upper threshold. Conversely, fifth, the audio input signal gain can be incrementally adjusted upward if the maximum signal amplitude falls below the lower threshold. Sixth, additional frames of unpredicted digital audio data samples can be received. Finally, seventh, each of the third through the sixth steps can be repeated with the received additional frames until the calculated maximum signal amplitude falls within the optimal range of audio signal amplitude.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a recording and reproducing method and a recording and reproducing apparatus using a probe, for writing and reading information by physical interaction between the probe having a tip at its distal end and a recording medium opposed thereto.
2. Related Background Art
There is recently developed a scanning tunneling microscope (hereinafter referred to as STM) enabling to directly observe an electronic structure of surface atoms of a conductor, whereby high-resolution measurement of a real, spatial image became possible, whether for a single crystal material or for an amorphous material. [G. Binnig et al. Phys. Rev. Lett, 49, 57 (1982)]
The STM utilizes the fact that a tunnel current flows when a metal probe (tip) is brought close to a conductive material, for example up to a distance of about 1 nm, while applying a voltage between them. This current is very sensitive to a change of the distance between them. Scanning the surface with the probe so as to keep the tunnel current constant, even a variety of information concerning a total electron cloud in a real space can be read. For the measurement the resolution is about 0.1 nm in in-plane directions.
Accordingly, applying the principle of STM, high-density recording and reproduction can be readily effected in the atomic order (sub-nanometer order). For example, a recording and reproducing apparatus, as disclosed in Japanese Laid-open Patent Application No. 61-80536, is so arranged that atom particles adhered to a surface of a medium are removed with an electron beam to write data and the written data is reproduced by STM.
There are suggestions concerning a method which employs as a recording layer a material having memory effect for switching characteristics of voltage-current, for example a thin-film layer of a material selected from π-electron organic compounds and chalcogen compounds, to record and reproduce data with STM (Japanese Laid-open Patent Applications No. 63-161552 and No. 63-161553). This method permits large-capacity recording and reproduction, for example at the density of 10 12 bit/cm 2 in case of the recording bit size being 10 nm. Further, some suggestions are directed to a reduction of the size, proposing apparatus in which a plurality of probes with respective tips are formed on a semiconductor substrate and a recording medium opposed thereto is displaced to record data (Japanese Laid-open Patent Applications No. 62-281138 and No. 1-196751). For example, if the above-described material having the memory effect is combined with a multi-probe head in which 2500 probes are arranged in a matrix of 50×50 on a 1-cm 2 -square silicon chip, recording or reproduction of digital data can be made at recording capacity of 400 Mbit per probe or at total recording capacity of 1 Tbit.
In such recording and reproducing apparatus, signals are normally recorded in the form of bits on the surface of the recording medium and the recorded bits are detected in the form of a level change of the tunnel current (in case of STM) upon reproduction. For example, in case of binary signals being recorded, bits are arranged on the recording medium to effect recording with presence or absence of bit and the information is read out detecting the tunnel current change between the probe tip and the recording medium (Japanese Laid-open Patent Application No. 63-96756). Another suggestion concerns analog signal recording of the tunnel current according to an information-writing size, using a medium which selects a charge or a magnetic domain in the molecular size depending upon recording data, as a recording medium (Japanese Laid-open Patent Application No. 2-210633).
The following problems are, however, recognized in the above cases where the data is recorded with presence or absence of bit or with difference of signal level and the recorded data is reproduced by detecting the presence or absence of signal or the signal intensity difference from recorded bits.
(1) As described previously, STM or AFM (atomic force microscope) has high resolution of angstrom order in the vertical direction. Thus, if it was used to construct a recording and reproducing apparatus of nanometer order, the high resolution in the vertical direction caused a large change of detected signals even with noise components such as defects or fine vertical undulations on the recording medium. Then flatness and uniformity of atomic level was required for the recording medium to be used in recording and reproduction. It has been difficult to produce a recording medium satisfying this requirement over a wide area. Therefore, it has been desired to achieve a recording and reproducing method which could permit recording and reproduction at sufficient S/N ratio even with some disturbance of flatness of the recording medium. Such suggestions have been rare.
(2) In the case where the analog signal recording was carried out by changing a modulation amount of recorded information bits in accordance with writing information size, the shape of recorded bits relying on the recording information must be formed with good reproducibility and at accuracy of angstrom order. It has been, however, actually difficult to effect the analog recording while changing the shape of recorded bits accurately in the angstrom order on an analog basis.
(3) In the recording and reproducing method utilizing the principle of STM, servo operation is normally employed to keep signals of the tunnel current constant between the tip and the medium. In case of the binary recording, for example, original signals were not used without modulation for recording, but modulation was necessary for the recording signals not to have a dc signal component. This needed a modulation circuit of complex structure and a demodulation circuit for demodulating modulated data.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a recording and reproducing method and a recording and reproducing apparatus using a probe, which can record and reproduce data at sufficient S/N ratio even with noise components and which can readily pick up horizontal and vertical position control signals between the probe and a recording medium without employing a modulation circuit or a demodulation circuit of complex structure.
The above object can be achieved by a recording and reproducing method for writing information in the form of bits by the physical interaction between a probe and a recording medium opposed to said probe, comprising:
a recording step of recording information by shifting a forming position of a bit by a predetermined shift amount in a horizontal direction of said recording medium in accordance with information; and
a reproducing step of reproducing said information, based on the shift amount of said recorded bit in the horizontal direction of said recording medium.
Further, the above object can also be achieved by a recording and reproducing apparatus for writing information in the form of bits by the physical interaction between a probe and a recording medium opposed to said probe, comprising:
recording means for recording information by shifting a forming position of a bit by a predetermined shift amount in a horizontal direction of said recording medium in accordance with information; and
reproducing means for reproducing said information, based on the shift amount of said recorded bit in the horizontal direction of said recording medium.
The present invention is directed to recording and reproduction in writing/reading information by the physical interaction between the probe and the recording medium opposed thereto, which is not the recording and reproduction of information utilizing the presence or absence of bit or the difference of size or height of bit, but is one where information is recorded as presence or absence of positional shift in serial bits or as a "shift amount" of each bit in a horizontal direction and the thus recorded bits are detected in reproduction. Generally, the STM has the resolution of sub-nanometer order in a horizontal direction. Therefore, among the recording and reproducing methods using an array of fine bits in the bit size of about 10 nm, the method to record and reproduce positional shifts of bits in a horizontal direction as in the present invention can detect signals with high S/N ratio and is unlikely to be affected by unflatness of the recording medium. Since the bits are approximately continuously recorded regardless of the contents of data to be recorded, the method of the invention has advantages that vertical/horizontal controls of the probe are easy in reproduction and that the bit arrangement is a recording/reproducing format suitable for recording and reproducing apparatus utilizing the principle of STM or AFM.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing to show the structure of a recording and reproducing apparatus having a conductive probe and a recording/reproducing format in embodiment 1 of the present invention;
FIG. 2 is a timing chart to illustrate a recording and reproducing method in embodiment 1;
FIG. 3 is a drawing to show a signal reproducing circuit employed in FIG. 1;
FIG. 4 is a drawing to show the structure of a recording and reproducing apparatus having a conductive probe and a recording/reproducing format in embodiment 2 of the present invention;
FIG. 5A is a drawing to show a phase modulation circuit 503 to perform phase modulation with binary information in a control circuit 408 in FIG. 4;
FIG. 5B is a timing chart to illustrate a recording and reproducing method in embodiment 2;
FIG. 6 is a drawing to show the structure of a recording and reproducing apparatus having a conductive probe and a recording/reproducing format in embodiment 3 of the present invention;
FIG. 7 is a timing chart to show a layout of bits in embodiment 3; and
FIG. 8 is a timing chart to show another example of layout of bits in embodiment 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will be described with reference to the drawings.
Embodiment 1
FIG. 1 is a drawing to show the structure of a recording and reproducing apparatus having a conductive probe and a recording/reproducing format in embodiment 1 of the present invention.
In FIG. 1, reference numeral 1 denotes a conductive probe, 2 a cylindrical piezoelectric device, which is a fine movement drive mechanism for driving the probe 1, and 3 a recording medium. The cylindrical piezoelectric device 2 is driven by a coarse movement drive mechanism such as a linear motor, not shown, to obtain an access to the recording medium 3. Numeral 10 designates an xy fine movement drive circuit to output an xy drive signal 15.
A bias circuit 4 normally applies a bias voltage 16 between the probe 1 and the recording medium 3, which are brought close to each other so that a tunnel current or field-emission current is ready to flow. The tunnel current or field-emission current is converted into a voltage signal by a current-voltage conversion circuit 5 and the voltage signal is supplied to a z-servo circuit 6. The z-servo circuit 6 outputs a distance control signal 7 to keep the tunnel current or field-emission current constant, and the distance control signal 7 is applied to an electrode 19 for driving the cylindrical piezoelectric device 2 in the z-direction. The probe 1 was formed by mechanically cutting platinum and making it pin-pointed.
The recording medium 3 was made of a material having the memory effect for switching characteristics of voltage-current. For example, used as a substrate electrode is an epitaxially grown surface of gold on a flat substrate such as glass or mica. Using squarilium-bis-6-octylazulene (hereinafter referred to as SOAZ) for the recording medium 3, a built-up film of double monomolecular layers thereof is formed on the substrate electrode by the Langmuir-Blodgett technique to produce the recording medium 3.
Recording of bits is carried out as follows. The bias circuit 4 normally applies the bias voltage 16 between the probe 1 and the recording medium 3, which are brought close to each other to the extent that the physical interaction takes place therebetween, specifically to the extent that a tunnel current flows herein. The probe 1 is moved to a desired position on the recording medium 3 in this state, and the bias voltage from the bias circuit 4 is modulated to apply a voltage exceeding a threshold voltage to cause the electric memory effect between the probe 1 and the recording medium 3, thus effecting recording. In fact, a bias voltage of about 0.1 V was applied through the bias circuit 4 between the probe 1 and the recording medium 3 and they were brought close to each other so that a constant tunnel current (1 pA) flowed. Keeping this state, the probe 1 was moved to a desired position on the recording medium 3. Then the control circuit 8 modulated the bias circuit 4 with bias modulation signal 11 to apply a pulse voltage of 6 V between the probe 1 and the recording medium 3. Then a bit was formed in the diameter of 10 nm so that a current of 10 to 100 pA could flow, and that state was kept after the application of pulse voltage. Then the bit in the low-resistance state was associated with "1" or "0", and bits were recorded as discriminating them from recording regions in a high-resistance state. In recording, the control circuit 8 generates a scanning signal 9 to drive the cylindrical piezoelectric device 2 through the xy fine movement drive circuit 10. As the probe 1 was two-dimensionally scanning the recording medium 3 in the xy raster scanning method, bits of "0" and "1" were recorded in the main scan (x) direction. After that, the recording medium 3 was scanned with the probe 1 to detect a shift amount of each bit from a reference bit position and the recorded information was reproduced as data of "0" and "1".
Specific recording and reproducing method and recording/reproducing format are next described referring to FIG. 1 and FIG. 2. FIG. 2 is a timing chart to illustrate a recording and reproducing method in embodiment 1. In recording, clock bits 200 necessary for recording and reproduction are recorded in the recording medium together with data bits 201 as a signal corresponding to a data input 17. A recording region of the recording medium 3 is divided into a head region where a clock signal is recorded and a data region where recording data is written. The clock bits 200 to be used in reproducing the recording data are recorded in the head region, from which the clock signal is taken out in reproduction. The recording data is recorded as binary data in the data region, in which bits corresponding to data of "0" and "1" are aligned as shown in FIG. 2. Namely, bits corresponding to information "0" are recorded at positions synchronized with the clock signal. On the other hand, bits corresponding to information "1" are recorded at positions phase-shifted in the main scan (x) direction from positions synchronized with the clock signal (FIG. 2).
Next described is the bit position shift recording in recording. Clock bits 200 and bits of information "0" were so recorded that, according to the timing from the control circuit 8, the bias modulation signal was generated when the probe passed a bit recording position, so as to apply the voltage to the recording medium. Since the bit diameter was about 10 nm, the clock bits and information "0" bits were formed at equal intervals of about 20 nm. For recording signals "1", the control circuit 8 generates an x-modulation signal 12 for modulating the cylindrical piezoelectric device 2 in the x-direction at the same time with the bias modulation signal 11. This shifts the position of the probe tip in the main scan (x) direction. When the bias circuit 4 generates the recording voltage in this state, a bit is recorded as phase-shifted in the main scan direction (x-direction) from the position synchronized with the clock signal. The cylindrical piezoelectric device 2 employed in the present embodiment is a PZT cylindrical piezoelectric device of 7 mm in outer diameter, 5 mm in inner diameter, and 15 mm in height. This piezoelectric device has divided drive electrodes, so that it can be three-dimensionally driven. Displacement characteristics of the PZT cylindrical piezoelectric device were measured using an electrostatic capacity displacement meter. Displacement sensitivity was 10 nm/V in the x- and y-directions. Thus, the control circuit 8 generated the modulation signal of 1 V as the xy modulation signal 12, so that in recording a recording signal "1" a bit was formed while shifting the probe by 10 nm in the main scan direction.
The shift amount of bit position was determined as follows. Bits are aligned at equal intervals as check bits on the recording medium 3. The bits are recorded at somewhat shifted positions depending upon the shape of the probe tip. The bit array is scanned after recorded, to check horizontal variations of bit-recorded positions. The shift amount is so determined that a recorded bit is shifted by an amount greater than the amounts of variations of bit positions in recording. The present embodiment is so arranged that the probe position is to be shifted by 10 nm in the main scan direction in recording a recording signal "1", because the positional variations of recording bits were not more than about 1 nm.
For reproducing the thus recorded bits, the current signal 13 was compared in phase with the reference of reproduction reference clock 202 stabilized based on the clock bit output from the head record region. Namely, the recording signal is "0", when the phase of clock output is the same as that of the current signal (i.e., when a phase difference is "0" between them). On the other hand, the recorded signal is "1", when the phase of clock output is shifted relative to that of the signal. A data output 18 was obtained while reproducing the data by phase comparison between the clock output and the current signal as described.
FIG. 3 is a drawing to show a signal reproducing circuit used in FIG. 1. The reproducing circuit is arranged as a part of the control circuit 8. In FIG. 3, the current signal 13 was put into a phase-locked loop (PLL 306) to reproduce the signal. In detail, the PLL 306 is composed of a phase comparator 302, a loop filter 303, an amplifier 304, and a VCO (voltage controlled oscillator) 305. In reproduction, the phase information of the current signal becomes significant. Thus, the current signal output 13 is amplified by the amplifier 300 and the amplified signal is subjected to amplitude limitation in limiter 301 to obtain a signal with constant amplitude. An output from the limiter 301 is put into the PLL 306. The PLL 306 performs phase comparison between the output from the limiter 301 and an output from VCO 305. The PLL 306 changes a control voltage from VCO 305 so that the two inputs have a minimum phase difference when a frequency of one becomes coincident with that of the other. Then VCO control voltage 307 for follow-up becomes a reproduction signal. Namely, the control voltage for follow-up is detected as a change of voltage value to produce a phase shift 90° because of the difference between the bits "0" and "1". It is binarized to obtain reproduction data 18 (FIG. 2).
In reproduction the control circuit 8 also performs a control of y-directional position in such a manner that while the probe is slowly modulated in the sub-scan direction (y-direction), a current detected from the recording bits on this occasion is shifted to synchronous detection. This position control signal is a tracking signal 14. In the present embodiment the recording bits are recorded as position-modulated only in the main scan direction, whereby bits appear approximately continuously. It was confirmed that, regardless of the contents of recorded data, the tracking signal 14 was continuously taken out and the position of probe 1 could be controlled easily.
There are cases where the clock bit output from the head record region cannot be obtained in a stable manner. It can be considered that it is, for example, because the probe tip was deformed so as to increase variations of bit-recorded positions whereby the array of clock bits zigzagged in recording. This would lower the S/N in recording and reproduction. In that case, the tip of probe should be cleaned to achieve reproducibility of bit-recorded positions, and then the recording and reproduction should be performed.
The recording method according to the present invention is by no means limited to the two-dimensional xy raster scan of the probe 1 on the recording medium 3 as shown in the present embodiment. For example, the probe may be moved in a circumferential or spiral pattern to record and reproduce bits as shifted in the circumferential track direction.
Although the present embodiment showed the recording and reproducing apparatus utilizing the STM, the concept of the present invention is by no means limited to it. The present invention can be applied to other recording and reproducing apparatus utilizing the AFM, which can record concave or convex portion or change of electron state of a recording medium surface with the probe in the nanometer order.
Embodiment 2
FIG. 4 is a drawing to show the structure of a recording and reproducing apparatus having a conductive probe and a recording/reproducing format in embodiment 2 of the present invention. The total structure well resembles that of embodiment 1 in FIG. 1. In FIG. 4, reference numeral 401 denotes a conductive probe, 402 a cylindrical piezoelectric device, which is a fine movement drive mechanism for driving the probe 401, and 403 a recording medium. The cylindrical piezoelectric device 402 is driven by a coarse movement drive mechanism such as a linear motor, not shown, to obtain an access to the recording medium 403. Numeral 408 designates a control circuit for outputting a scanning signal 409 and a tracking signal 414, and 421 an xy fine movement drive circuit for outputting an xy drive signal 415.
A bias circuit 404 normally applies a bias voltage 416 between the probe 401 and the recording medium 403 while the probe 401 and the recording medium 403 are brought close to each other to the extent that a tunnel current or field-emission current flows. The tunnel current or field-emission current is converted into a voltage signal by a current-voltage conversion circuit 405 and the voltage signal is supplied to a z-servo circuit 406. The z-servo circuit 406 outputs a distance control signal 407 so as to keep the tunnel current or field-emission current constant. The distance control signal 407 is applied to an electrode 419 for driving the cylindrical piezoelectric device 402 in the z-direction. The probe 401 was produced by mechanically cutting platinum and making it pin-pointed.
For the recording medium 403, a material employed was one having the memory effect for the switching characteristics of voltage-current, similarly as in embodiment 1.
Embodiment 1 was so arranged that in recording binary bits the recording was carried out as shifting the probe in the main scan (x) direction with the xy drive signal from the xy fine movement drive circuit 10, while the present embodiment is so arranged that recording is made as shifting the bit position in the main scan direction by controlling application timing of recording voltage from the bias circuit 404. A specific recording method of the present embodiment will be described referring to FIGS. 5A and 5B. FIG. 5A is a drawing to show a phase modulation circuit 503 for performing phase modulation with binary information in the control circuit 408 of FIG. 4, and FIG. 5B a timing chart to illustrate the recording and reproducing method in embodiment 2. Two phase-shifted carrier waves (carrier wave 420 in FIG. 4) are prepared and binary data "0" and "1" is converted into phase information of the respective carrier waves. In FIGS. 5A and 5B, the two carrier waves 501, 502 may be expressed as follows.
y=A·sinωt: carrier wave 501
y=A·sin(ωt-π/2): carrier wave 502
The carrier waves 501, 502 prepared are shifted 90° in phase to each other. The frequency of carrier waves 501, 502 is determined by a maximum space frequency at which bits can be recorded on the recording medium, and the scanning speed of the probe tip. For example, if the size of bits is 10 nm, the recording pitch is 20 nm, and the scanning speed of the probe is 200 μm/sec, then the frequency of carrier waves 501, 502 is set as 10 kHz. The selection circuit 503 changes over to select the carrier wave 501 or the carrier wave 502 with "0" or "1", respectively, of data input 417 as the binary recording data. The timing control of the bias circuit 404 is carried out based on a phase modulation signal 504 output from the selecting circuit 503. Namely, the phase modulation signal 504 is put, for example, into a binarizing circuit 505 to produce a bias modulation signal 411, which is a timing signal to generate a recording voltage. Recording was effected by modulating the bias voltage 416 with the bias modulation signal 411.
The reproducing circuit is the same as that in FIG. 3. Namely, a PLL is constructed of a phase comparator, a loop filter, an amplifier, and a VCO (voltage controlled oscillator). Phase information of reproduction signal becomes significant. Thus, an output of current signal 413 is amplified and the amplified signal is amplitude-limited in a limiter so as to have a constant amplitude. An output from the limiter is put into the PLL. The PLL performs phase comparison between the limiter output and an output from VCO and changes the output from VCO so as to make a phase difference between them minimum when the frequency of one is coincident with that of the other. In this case, a demodulated signal is a control voltage for phase follow-up. The VCO control voltage for follow-up appears as a change of a voltage amount to cause a phase shift of 90° with a bit difference between "0" and "1". Then, the binary data is reproduced by binarizing the control voltage signal to obtain a data output 418.
Although the present embodiment was so arranged that the binary data was modulated with two carrier waves different in phase to record bits, the binary data may be modulated with two different frequencies to record bits.
Embodiment 3
FIG. 6 iS a drawing to show the structure of a recording and reproducing apparatus having a conductive probe and a recording/reproducing format in embodiment 3 of the present invention. The entire structure well resembles that of embodiment 1 in FIG. 1. In FIG. 6, reference numeral 601 denotes a conductive probe, 602 a cylindrical piezoelectric device, which is a fine movement drive mechanism for driving the probe 601, and 603 a recording medium. The cylindrical piezoelectric device 602 is driven by a coarse movement drive mechanism such as a linear motor, not shown, to obtain an access to the recording medium 603. Numeral 621 is an xy fine movement drive circuit for outputting an xy drive signal 615.
A bias circuit 604 normally applies a bias voltage 616 between the probe 601 and the recording medium 603 while the probe 601 and the recording medium 603 are brought close to each other to the extent that a tunnel current or field-emission current flows. The tunnel current or field-emission current is converted into a voltage signal by a current-voltage conversion circuit 605 and the voltage signal is supplied to a z-servo circuit 606. The z-servo circuit 606 outputs a distance control signal 607 so as to keep the tunnel current or field-emission current constant. The distance control signal 607 is applied to an electrode 619 for driving the cylindrical piezoelectric device 602 in the z-direction. The probe 601 was produced by mechanically cutting platinum and making it pin-pointed. The bias voltage 616 is modulated with a bias modulation signal 611.
For the recording medium 603, a material employed was one having the memory effect for the switching characteristics of voltage-current, similarly as in embodiment 1.
Embodiment 1 was so arranged that in recording, bits were recorded as shifting the probe in the main scan (x) direction with the xy drive signal from the xy fine movement drive circuit 10, while the present embodiment is so arranged that analog recording of data input 617 is carried out as shifting the probe in a direction (y-direction) perpendicular to the main scan and that an amount of the shift is detected as an analog value to perform analog reproduction as data output 618.
Next described is the bit-position-shifting recording in which positions of bits are shifted in recording. FIG. 7 is a timing chart to show a layout of bits in embodiment 3. Bits include clock bits 701 continuously aligned and information bits 702, each having an amount of positional shift in the sub-scan (y) direction from the clock bits 701, as analog recording information.
The control circuit 608 modulates the bias circuit 604 to record the clock bits 701 at equal intervals while moving the probe in the main scan (x) direction. After completion of recording of the clock bits, the control circuit records bits while shifting the probe in the y-direction in accordance with an amount of analog signal to be recorded.
In fact, because the bit size was about 10 nm, the clock bits 701 were formed at equal intervals of about 20 nm. On the other hand, for recording the information bits the control circuit generated the y-modulation signal 612 for modulating the xy fine movement drive unit, whereby bits were recorded as the probe tip was shifted in the sub-scan (y) direction.
The cylindrical piezoelectric device employed in the present invention is also a PZT cylindrical piezoelectric device, which is the same as that in embodiment 1. Since this piezoelectric device had the displacement sensitivity of 10 nm/V in the x and y directions, the modulation circuit generated a voltage of at most 2 V depending upon an analog amplitude amount of recording signal, so that the positional shift of at most 20 nm appeared in the sub-scan (y) direction. Recording was carried out by performing the main scan while forming bits shifted in the sub-scan direction from the positions of the clock bits, as described.
Next described is a method for reproducing the thus recorded bits. In reproduction, the control circuit produces a scanning signal 609 to perform the main scan (x-directional scan) while oscillating (wobbling) the probe within the width of about 30 nm in the sub-scan (y) direction, thus reproducing information.
On this occasion, a reproduction clock is produced based on the signal from the clock bits. A position control (tracking) signal 614 in the y-direction is generated by phase comparison between the reproduction clock and the wobbling signal, so as to perform a horizontal position control thereby. In a tracking state the probe 601 performs the main scan (in the x-direction) along the clock bit array. In this state the current signal 613 is subjected to phase detection with the reproduction clock signal, and a wave detector provides, as a phase difference signal, a signal according to a positional shift amount of each recording bit from the clock bit. This is reproduced as an analog data output 618.
The bit layout in the bit-position-shift recording is not limited to that shown in FIG. 7, but may be one as shown in FIG. 8. In the layout of FIG. 8, two paired bits are recorded in the sub-scan (y) direction while moving the probe in the main scan (x) direction. In this case, the recording is done while a distance between two bits in each bit pair is changed in an analog manner. For example, if the bit diameter is 10 nm, bits are to be recorded at the pitch of 20 nm in the main scan direction. As an example, bits were recorded as changing the bit distance within at most 20 nm according to values of analog data. In reproduction, the main scan was carried out while wobbling the probe in the width of 40 nm in the sub-scan direction to detect signals from the recorded bits. Since the bits were formed at the pitch of 20 nm in the main scan direction, the thus detected signals were demodulated using the clock determined by the pitch and the probe scanning speed so as to reproduce the data.
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A recording and reproducing method writes information in the form of bits by the physical interaction between a probe and a recording medium opposed to the probe. The method includes a recording step of recording information by shifting a forming position of each bit by a predetermined shift amount in a horizontal direction of the recording medium in accordance with information, and a reproducing step of reproducing the information, based on the shift amount of each recorded bit in the horizontal direction of the recording medium. A recording and reproducing apparatus is so constructed as to perform the steps.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a drying section for drying a moving web in a web-handling apparatus, the drying section formed preferably as a part of a paper-making machine.
2. Description of the Prior Art
A drying section is described in German Patent DE 3,623,971 as having a number of drying cylinders disposed to form a two-felt drying group comprising an upper and a lower row of cylinders. In each row of cylinders, at least two adjacent cylinders form a sub-group. A deflection suction roll, which guides a felt, wire or like component (hereinafter referred to generally as a "felt"), together with a web to be dried, from the first to the second cylinder of the sub-group, is provided between the two cylinders. After passing through a sub-group (for example in the lower row of cylinders), the web runs over a so-called "web path" to a sub-group of the upper row of cylinders. These two sub-groups overlap one another so that the second cylinder of the lower sub-group lies beneath the first cylinder of the upper sub-group. After passing through the upper sub-group, the web again transfers downwardly to a further sub-group of the lower group of cylinders. It is also known from the above-noted German Patent to provide guide rolls for guiding the respective felts to one of the sub-groups and from there to the following sub-group (in the same row of cylinders). These guide rolls are disposed along the "web path" so that the web to be dried is guided a short distance by the felt, then runs freely for a short distance and then is conveyed for a short distance by the felt of the other row of cylinders to the following cylinder. The arrangement is also such that in the region of one deflection suction roll of one row of cylinders, there is located a predetermined section of the felt path of the other row of cylinders which is free from the web and touches two felt rolls. An air-blast box is also provided for blowing dry air onto the web to be dried at a point where the web runs together with the respective felt over the deflection suction roll. The air-blast box is disposed between the deflection suction roll and the above-mentioned predetermined section of the felt path.
On the one hand, the drying efficiency of the known drying section can be increased with the assistance of the air-blast boxes mentioned above. On the other hand, a problem occurs in the so-called pockets, which are very narrow, if the web to be dried tears. If the web to be dried tears, pieces of the torn-off web (the so-called "broke") remain hanging on the air-blast boxes. It is then normally necessary to stop the drying section to remove the broke. A further complication is that the air-blast boxes cannot be swivelled away (or can only be swivelled a short distance) from the deflection suction rollers because of the restricted spatial conditions.
An advantage of the drying section arrangement discussed above lies in that the number of the so-called "web paths" (between the upper and the lower row of cylinders) is roughly one half less than in the two-felt drying group normally used in a papermaking machines, in which, after each single cylinder, the web transfers from one row of cylinders to the next. The problem of web tears occurs therefore substantially less frequently than in conventional drying sections, but is in no way completely solved.
SUMMARY OF THE INVENTION
An object of the invention is to improve the drying section described in German Patent 3,623,971 so that the removal of broke is facilitated, and can take place without interrupting the operation of the drying section.
According to the invention, in such a known drying section, the space defined between the deflection suction roller and the predetermined section of the felt path is completely free from components. Thus, the air-blast boxes previously provided between each deflection suction roll and the adjacent section of the felt path are completely omitted. Therefore, in the pockets, there is no longer anything present to which broke could become attached. As a result, with the arrangement according to the invention, there is a tendency for broke to be transported further by the rotating cylinders and moving felts towards the end of the respective drying group, where it is discharged downwardly. This tendency is enhanced by the fact that the felt rolls are disposed in close proximity to or at a slight distance from the "web path". As known from the above-mentioned German Patent, this slight distance may even be equal to zero. In this case, the web can move freely for a short distance on the "web path", i.e. unsupported by one of the felts. Another possibility lies in that the two felts (i.e. the upper felt and the lower felt) overlap one another along the web path. In this case, the web moves "without free web draw" from the upper to the lower row of cylinders or vice versa.
A two-felt drying group having similar components is known from European Patent 0368937. However, there the felt is only guided over a single roll from one sub-group to the next, inside each row of cylinders. Therefore, the "web path" is free over its entire length from a lower to an upper cylinder or vice versa, i.e. completely unsupported by one of the felts. In fact, an attempt has been made to compensate for this disadvantage by an extremely small height spacing between the two rows of cylinders and thus, by very short "web paths". However, this results in very restricted space conditions.
Furthermore, when threading the so-called "strip", or tail, the known arrangement causes difficulties. A "strip" is a narrow edge strip of the paper web which is initially passed through the drying section when starting the paper making machine. After this strip has successfully passed through the drying section in a stable manner, the paper web is gradually introduced to its full width in a known manner. The threading of the strip should occur completely without the assistance of a rope guide which is normally provided for this purpose, thereby reducing the possibility of breakdown and accidents. Thanks to the at least partial guidance of the web by the felts on the so-called "web paths" (from the upper to the lower row of cylinders or vice versa) an automatic, i.e. rope-free, introduction of the strip, can be easily achieved, if necessary with the assistance of pneumatic strip guiding devices.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Further inventive features will become apparent from the following description of one embodiment of a drying section in accordance with the invention, and modifications thereof, in which:
FIG. 1 is a schematic side view of one embodiment of the present invention including a drying section with several two-felt drying groups;
FIG. 2 is a schematic partial side view of a modification of an initial region of the drying section of FIG. 1;
FIG. 3 is a schematic partial side view of a modification of an initial region of the drying section of FIG. 1;
FIG. 4 is a schematic partial side view of a modification of a rear region of the drying section of FIG. 1; and
FIG. 5 is a schematic partial side view of a modification of a rear region of the drying section of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The drying section represented in FIG. 1 has three two-felt drying groups 11-13 disposed one after the other. Each of these drying groups includes an upper and a lower row of cylinders having an upper felt OF and a lower felt UF. In the upper row of cylinders of the first two-felt drying group 11, three cylinder pairs 14, hereinafter referred to as a "sub-group", are disposed behind one another. On the other hand, the lower row of cylinders of the first drying group 11 includes only two sub-groups 15 each having two cylinders. Deflection suction rolls 14' and 15', respectively, which come into direct contact with the respective felts (while the cylinders themselves come into direct contact with the paper web 9 to be dried) are provided between the two cylinders of each sub-group 14, 15. Respective pairs of felt rolls 24 are disposed between adjacent upper sub-groups 14 in order to guide the upper felt from one sub-group to the next. Two felt rolls 25 are also provided between the two lower sub-groups 15. Further felt rolls (without reference numbers) guide the felts in a known manner from the end of each row of cylinders back to its beginning.
The paper web 9 runs initially through the first upper sub-group 14 and then transfers to the first cylinder of the first lower sub-group 15. The paper web runs from the second cylinder of the first lower sub-group 15 back in the upward direction to the first cylinder of the second upper sub-group 14, etc.
In the exemplified embodiment shown in FIG. 1, the first cylinder of the first lower sub-group 15 lies exactly beneath the second cylinder of the first upper sub-group 14. In precisely the same manner, the first cylinder of the second upper sub-group 14 lies exactly above the second cylinder of the first lower sub-group 15, etc. However, the cylinders do not always have to lie exactly vertically above one another. The only important thing is that the upper and lower sub-groups overlap one another. It is also advantageous for the felt rolls (e.g. 24 and 25) to be disposed so that the felts OF and/or UF are conveyed a short distance with the paper web 9 on the "web path".
An air-blast box 21 can be provided between two felt rolls 24 lying between two adjacent sub-groups 14. This box 21 is therefore situated, in contrast with the known arrangement, inside the loop of the respective felt OF. The air-blast box 21 blows dry and preferably heated air into the interior of the pocket T to remove moisture from the pocket in a known manner. A doctor 22 is located beneath the second cylinder of the last upper sub-group 14 and beneath it a relatively wide gap is located between the two lower felts UF of the first and second drying groups 11, 12. Should the web tear, the broke runs substantially as in normal operation through the drying group and is downwardly discharged through the above-mentioned relatively wide gap.
The second drying group 12 is constructed in substantially exactly the same way as the first. There are again three upper sub-groups 16 each having two cylinders. The lower row of cylinders also includes three sub-groups 17 each having two cylinders. Thus, the first lower cylinder of the second drying group 12 lies beneath the last upper cylinder of the first drying group 11, so that here the paper web can transfer from the first to the second drying group. In exactly the same manner, the paper web--after passing through the entire second drying group 12--transfers from the second cylinder of the last upper sub-group 16 to the first cylinder of the first lower sub-group 19 of the third drying group 13. This has three lower sub-groups 19 each having two cylinders, while the upper row of cylinders has two sub-groups 18 and a single last cylinder 20, from which the dried paper web 9 runs off. It is obvious that the number of cylinders per drying group and/or the number of drying groups can be varied at random, depending on the requirements of the type of paper and/or the operating speed. Deflection suction rolls 16'-19', felt rolls 26-29 and air-blast boxes 21 are also provided in drying groups 12 and 13. A tail cutter provided in the end region of the last drying group 13 is designated by SS.
FIG. 2 shows that a drying group can also be composed of sub-groups each having three cylinders. This is represented with the example of a first drying group 31, in which case the paper web 9 again initially passes through an upper sub-group 34, then transfers to a lower sub-group 35 and from there to a second upper sub-group 36. The sub-groups 34, 35, 36 mutually overlap. In the overlapping zones, a lower cylinder now however lies opposite a gap between two upper cylinders and vice versa. The following drying group 32 then has sub-groups 37, 38 each having two cylinders as in FIG. 1, which then lie vertically above one another in pairs. The first cylinder of the first lower sub-group 37 of the second drying group 32 also lies directly beneath the last cylinder of the second upper sub-group 36 of the first drying group 31.
The drying section shown in FIG. 3 differs from that in FIG. 1 firstly by the fact the lower row of cylinders of the first drying group 41 only has a single sub-group 45 with two cylinders. This sub-group lies beneath the fourth and fifth cylinders of the upper row of cylinders, which in turn has a total of six cylinders. Consequently, the first upper sub-group 44 has a total of four cylinders, the second sub-group 46 on the other hand has only two cylinders as before. This arrangement is advantageous if, with a paper web which is difficult to treat, there is the danger that tears to the web have to be expected relatively frequently right in the initial region of the drying section.
In both FIGS. 2 and 3, the deflection suction rolls 34', 36' and 44', 46', respectively, of the first drying group each have an inner suction box which limits (defines) a determined suction zone. Such suction rolls are preferably disposed non-symmetrically between two adjacent cylinders. The distance to the preceding cylinder is substantially less than to the following cylinder. This facilitates the safe detachment of the still damp web from the preceding cylinder. Another possibility is represented in the second drying group 32 and 42, respectively in FIGS. 2 and 3. In the second drying group 32 and 42, deflection suction rolls 37' and 47', 48' respectively, are provided. These deflection suction rolls 37' and 47', 48' respectively, do not have an internal suction box and the rotatable roll body of each of the deflection suction rolls does not have any suction connection either. The shell of these deflection suction rolls has circumferential grooves or is preferably perforated, as in the case of normal suction rolls. An external suction box S is provided at the sector of the roll periphery not covered by the felt. At the preceding cylinder, suction box S has a deflection bar for the air boundary layer advanced by the felt.
FIGS. 4 and 5 show that a two-felt drying group according to the invention may be the last drying group 69 and 79, respectively, of a mixed drying section. This means that the first drying groups are constructed as single-felt drying groups. Each of these single-felt drying groups has a single endless felt, which runs together with the web to be dried alternately over cylinders and deflection suction rolls.
Several variants are possible. All single-felt drying groups can be felted at the top. Another possibility is shown in FIGS. 4 and 5, in which at least one of the single-felt drying groups 67, 68 and 77, 78 respectively, is felted at the bottom. In FIG. 4, this is the second to last single-felt drying group 67, while in FIG. 5, on the other hand, it is the last single-felt drying group 78, which is disposed immediately in front of the two-felt drying group 79. Accordingly, in FIG. 4, the paper web 9 runs from the last cylinder of the last single-felt drying group 68 initially to a single lower cylinder 61 of the two-felt drying group 69 and from this, the web 9 runs successively through sub-groups 62-65 (each having two cylinders with a deflection suction roll 62'-65' therebetween). At the end, a single upper cylinder 66 is provided. However, in FIG. 5, the web 9 runs upwardly from the last cylinder, felted at the bottom, of the last single-felt drying group 78 to a first cylinder of an upper sub-group 72 and after this, as in FIG. 4, via further sub-groups 73-75 each having two cylinders and finally over a single cylinder 76.
With reference to FIG. 2, it is now explained how the automatic, ropeless strip insertion into the two-felt drying group according to the invention can be performed. A machine-width doctor 50 (i.e. a doctor extending transversely across the entire machine width) is provided at one of the upper cylinders. The doctor 50 detaches the tip of the incoming strip from the cylinder and conveys it by means of an air-blast nozzle (symbolically represented by an arrow) to the following deflection suction roll 36'. In a known manner, this may have an edge suction zone for the strip, which has stronger suction during the strip insertion operation. In addition to a machine-width doctor 53, other cylinders have relatively short edge doctors 51 equipped with air blowing devices which extends just over the region of the strip, e.g. as described in German Patent DE 8914679. Further cylinders only have short edge doctors 51, i.e. without air blowing devices, as shown. In addition, a so-called pneumatic guide plate 52 can be provided, in particular on an upwardly leading "web path", e g. as described in German Patent DE9109313. A perforated belt conveyor, which is connected to a low pressure source, as described in U.S. Pat. No. 4,022,366, may be provided for the strip insertion instead of, or in addition to, air blowing devices.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
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A drying section for use in a papermaking machine has a two-felt drying group with an upper row of cylinders and an upper felt and with a lower row of cylinders and a lower felt. In each row of cylinders, two adjacent cylinders form a sub-group having a deflection suction roll disposed therebetween. A web to be dried passes alternately through the upper and lower sub-groups. Opposite each deflection suction roll of one row of cylinders lies a section of the felt path of the other row of cylinders, the space located therebetween being free from components to facilitate removal of paper broke.
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INTRODUCTION
This invention relates to a circuit configuration for an anti-lock-controlled brake system, which circuit configuration serves for processing sensor signals that have been obtained by means of wheel sensors and that represent the rotational behavior of the vehicle wheels and for generating braking pressure control signals by means of which solenoid valves inserted into the brake lines can be changed over, and which circuit configuration is provided with two or more microcontrollers that are interconnected by data exchange lines and can be fed with the sensor signals after the same have been handled in a trigger circuit, with the microcontrollers independently of one another processing the sensor signals, generating the braking pressure control signals, checking the exchanged signals for consistency and feeding a monitoring signal to a safety circuit which interrupts the power supply to the solenoid valves in case of malfunctions.
BACKGROUND OF THE INVENTION
Such a circuit configuration has come to knowledge from German Published Patent Application (DE-OS) No. 3234637. The handled signals of all wheel sensors are fed concurrently to two electronic circuits and are there processed by means of identical logic or rather in accordance with identical programs for the purpose of identifying malfunctions of the electronic circuitry. The signals available at different points in the course of the program are exchanged and checked for consistency. Any deviations are an indication of malfunctions wherefore in such a case either of the two electronic circuits signalizes this malfunction to one or several safety circuits. This causes a cut-off of the power supply to the solenoid valves serving for anti-lock control. As, in their rest positions, the solenoid valves do not influence the pressure medium supply to the brake and, hence, the brake application, nor permit any pressure removal via the outlet valves it is ensured that the vehicle will continue to be able to be braked, although without anti-lock control, in case of a trouble in the electronic system.
BRIEF DESCRIPTION OF THE INVENTION
However, in such a circuitry it is conceivable, although unlikely, that there are cases where anti-lock control will remain switched on despite a malfunction. Therefore, it is an object of the present invention to enhance the degree of safety even more, with which anti-lock control will be switched off in case of a trouble in the electronic or electric system, and thus to increase the safety of maintaining the braking operation, although without control. This object ought to be achieved without any additional expense or with very little additional expense at the maximum.
It has been found out that this object can be solved in a circuit configuration of the type referred to at the beginning in that, in case of consistency of the exchanged signals and in case of proper operation of the circuitry, the monitoring signal of each microcontroller is a predetermined alternating signal, i.e., an alternating signal with predetermined frequency and with predetermined variation; and in that the safety circuit compares the monitoring signal, or rather the alternating signal, with a time standard derived from one or several clock generators which are independent of the operating cycle of the microcontrollers.
According to this invention, the enhanced safety will thus be achieved in that an alternating is selected as monitoring signal by means of which each microcontroller signalized the proper condition to the safety circuit; and in that this alternating signal is compared with a time standard. The alternating signal, for instance, is a pulse sequence of predetermined duration and frequency. Moreover, a time standard, or rather a time window, is used for the monitoring signal of each microcontroller. Said time standard, or rather time window, is gained independently of the operating cycle of the microcontrollers by means of additional clock generators. These clock generators may be of simple construction as they only have to check relatively roughly whether the monitoring signal falls into the predetermined time window. Such clock generators, for instance, permit integration at low expense into the trigger circuit provided for the wheel sensor signals.
Should there be a failure of the clock generators defining the time windows this would also lead to a cut-off of anti-lock control. Thus the monitoring assemblies are also included in the monitoring operation.
According to one advantageous embodiment of this invention, the monitoring signal of each microcontroller is compared with the time window derived from a specific clock generator. As compared with the use of a common clock generator this will once more enhance the safety degree of error detection.
It will be an advantage if, upon error detection, the safety circuit interrupts the power supply path of a relay via the operating contact of which power supply to the solenoid valves takes place. A very expedient embodiment of such a circuit configuration for actuating the power supply relay is described in the German Patent Application No. P 39 24 988.3. If such a circuit configuration is used it will be ensured that power supply will be interrupted even in case of troubles of various types within the relay actuation system.
A further very advantageous embodiment of this invention consists in that, upon error detection, the safety circuit actuates semiconductor stages such as transistor stages via an additional signal output which block the actuation of the solenoid valves, e.g., by interrupting power supply to the driver stages, or rather amplifier stages, connected upstream of the solenoid valves. In this way, any further anti-lock control will be prevented even if the detected trouble admittedly will cause the safety circuit to respond, with the supply voltage, however, not being switched off because of a bridged switching contact, for instance.
According to a further embodiment of this invention, the microcontrollers will not only signalize defective operation if the mutually exchanged signals are not consistent but also if there appear signals or signal combinations which will not be possible in case of proper operation of the anti-lock control system. Monitoring thus also takes place in accordance with so-called plausibility criteria.
According to another favorable example of an embodiment of this invention, the output signal of a monitoring circuit is feedable to the microcontrollers, the error detection state of said output signal--e.g., a permanent signal instead of an alternating signal--being signalizable as malfunction to the safety circuit by means of the microcontrollers and of the monitoring signals. The output signal, for instance, may be an output signal of a parity chain monitoring the operation of the solenoid valves. A very advanced monitoring circuit of this type is described in German Patent Application No. P39 25 418.8.
Further characteristics, advantages and applications of this invention will become evident from the following description of one example of an embodiment, reference being made to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1, is a block diagram showing the essential components of a circuit configuration in accordance with this invention; and
FIG. 2, shows details of one component of the circuit configuration as per FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In accordance with FIG. 1, the essential components of a circuit configuration for an anti-lock-controlled brake system are two microcontrollers 1,2 (MC1 and MC2) which, via signal lines 3, 4, are fed with the information on the rotational behavior of the individual vehicle wheels and which generate braking pressure control signals after these signals have been logically linked and handled.
The wheel information are obtained in the known manner by means of wheel sensors 5 whose signals are processed in a trigger circuit 6 and, subsequently, are passed on to the microcontrollers 1, 2. In the illustrated example of an embodiment, via lines 3 and 4, respectively, each microcontroller is fed the information of two wheel sensors out of the four wheel sensors; however, via the data exchange lines 7, the wheel information are also exchanged so that, independently of each other, in both microcontrollers it will be possible to derive braking pressure control signals from the input information, with the same program being used.
The output signals of the microcontrollers 1, 2 serve as braking pressure control signals. After amplification in valve drivers VT1, VT2 . . . VTn, said output signals will be fed to power transistors LT1, LT2, . . . LTn which directly actuate solenoid valves. The excitation coils of the solenoid valves are referred to by L1, L2 . . . Ln. The (non-illustrated) solenoid valves serve for braking pressure modulation within the scope of anti-lock control. In the rest position said solenoid valves do not have any influence on the braking operations.
The braking pressure control signals are likewise generated independently of one another in both microcontrollers 1, 2, and are compared via data exchange lines 7. In the illustrated example of an embodiment, the connections to the individual solenoid valves are distributed to the two microcontrollers 1, 2 because of the limited number of the available outputs, or rather connection pins.
Monitoring lines WD1, WD2 lead from the microcontrollers 1, 2 to a safety circuit 8. Via outputs of said safety circuit 8, two power transistors LT3, LT4 are actuated that are connected in series and via which a power supply relay, or rather a main relay 9, is energized which, via an operating contact 10, maintains the power supply to the solenoid valve and their actuation circuits (VT1 . . . VTn). A circuit 11 serves for the voltage supply UB of the safety circuit 8 and for triggering a reset pulse.
A further output of the safety circuit 8 leads to two cascade-connected transistors 12, 13. In case of proper operation, transistor 13 is conductive and supplies the valve drivers VT1, VT2 . . . VTn as well as the power transistors LT1, LT2 . . . LTn with energy. Power supply to the valve drivers and power transistors will be blocked via transistor 13 if transistor 12 is actuated by safety circuit 8.
A monitoring circuit 14 to be explained in more detail in the following with reference to FIG. 2 supplies a signal to the two microcontrollers 1, 2 via a line 15. In a certain way, said signal will be dependent on the correction signals of the microcontrollers 1, 2, or rather on the actuation of the solenoid valves L1 . . . Ln, as long as the monitored elements and windings L1, L2 . . . Ln are in good order. If a trouble comes up the signal at output A will deviate from the "expected" signal.
A clock generator TG1 is provided for the generation of an operating cycle for the microcontrollers 1, 2, its clock frequency being determined by a quartz. The operating cycle of the microcontrollers 1, 2 also determines the frequency and the shape of the monitoring signals WD1, WD2 that signalize intact condition and proper operation to the safety circuit. In one example of an embodiment of this invention, the monitoring signals WD1, WD have the shape of short pulses of a duration of 200/us which are repeated every 7 ms.
Two further clock generators TG2, TG3 which are independent of clock generator TG1 are provided for the generation of time windows or time standards by means of which the monitoring signals are comparable. In the present example, said clock generators TG2, TG3 are integrated into the trigger circuit 6.
Monitoring of the circuit configuration as per FIG. 1 will be performed as follows:
The two microcontrollers 1, 2 contain circuits that permanently perform a consistency check of the signals exchanged via the data exchange lines 7. Moreover, in a manner known per se, it is established within the circuits 1, 2 whether predetermined plausibility criteria are complied with, or rather whether the signals formed within the scope of signal processing will be possible in case of intact circuitry and proper operation. Finally, it is also checked whether an alternating signal is actually available at output A of the monitoring circuit 14, or rather at the corresponding inputs which are given access to by line 15. If all these conditions are complied with independently of one another in either of the microcontrollers 1, 2 this will be signalized to the safety circuit 8 by means of the monitoring signals WD1, WD2 which, in this case, represent an alternating signal of a certain shape and frequency such as a pulse sequence of a certain frequency.
The two monitoring signals WD1, WD2 are compared independently of each other with corresponding time standards derived from the clock generators TG2, TG3. As long as there is no deviation indicating a trouble or a malfunction the power transistor LT3, LT4 connected to the corresponding outputs of the safety circuit 8 can be activated, the relay 9 remaining switched on. The voltage UB is applied to the illustrated circuit and to the solenoid valves. There is no signal at the third output of the safety circuit 8, which leads to transistor 12, so that also the valve drivers and the power transistors are connected to the battery voltage UB via transistor 13.
If now there occurs a malfunction detected by the monitoring circuit 14 and/or by the microcontroller 1 and/or 2 this will lead to a corresponding change in the monitoring signal WD1 and/or WD2. The safety circuit 8 will react by ending actuation of transistors LT3, LT4, thereby causing relay 9 to drop out and interrupting the power supply to the entire circuitry. Additionally, the power supply to valve drivers VT1 . . . VTn and to power transistors LT1 . . . Ltn will be blocked in the described way via the third output of the safety circuit 8. This, however, will only be of importance if cut-off via relay 9 does not work or is delayed.
A corresponding reaction of safety circuit 8 will also come about if one or both monitoring signals WD1, WD2 are no longer consistent with the time standards derived from the clock generators TG2, TG3 or if either clock generator TG2, TG3 becomes defective, with the monitoring signals WD1, WD2 being intact. Consequently, the monitoring elements themselves are monitored .
FIG. 2, referring to an example of an embodiment with four solenoid valves whose excitation windings are referred to by L1-L4, serves to explain the connection and mode of operation of the monitoring circuit 14 of FIG. 1. This circuit is described in detail in Patent Application No. P 39 25 418.8 mentioned at the beginning.
The signal at output A, or rather on line 15, is dependent on the signal variation, or rather on the signal distribution, at all the outputs of the microcontrollers 1, 2 that are connected via the monitoring circuit 14. For instance, a change in the signal level at any one of the outputs of the microcontrollers 1, 2 with the levels at the remaining outputs staying the same, automatically will cause a change in level on line 15. In the microcontrollers 1, 2 it will always be checked whether the signal at the output of monitoring circuit 14 will be in conformity with the signal distribution at the outputs of the microcontrollers 1, 2.
The transistors T1-T4 of the monitoring circuit 14, together with the remaining components combined in circuit block 16, form an OR-link whose output signal is formed by means of transistors T5, T6 and is available at an output A1. Connected at the base of transistor T5 are a current source Q1 towards the ground and an ohmic resistor R1 towards the supply voltage UB. The emitter of transistor T5 is connected with the battery UB via a low-impedance resistor R2. The current source Q1, the base resistor R1 and the emitter resistor R2 are dimensioned such as to ensure that, as long as the transistors T1-T4 are non-conductive, the two transistors T5 and T6 will carry a current so that there will prevail the signal state L (low) at output A1.
There will be a change in the level at output A1 if at least one valve is excited, or rather if one of transistors LT1 . . . LTn is actuated (in FIG.2 only LT1 and the appertaining driver stage VT1 are sketched out).
As long as the power transistors are not actuated the transistors T1-T4 will be non-conductive as each transistor base, which in each case is connected to the battery voltage UB via one of the low-impedance windings L1-L4, is on the potential of the voltage source UB. The current flowing via R2 and the transistors T5, T6 will cause a drop in voltage in the blocking direction of the base-emitter diode of transistors T1-T4.
The base connections of transistors T1-T4 are connected to one output A2 by means of non-equivalent elements XOR1, XOR2, XOR3 (exclusive OR). Each of said non-equivalent elements has two inputs and one output and they are combined into a so-called parity chain in that in each case a control connection of a valve excitation winding is linked with the output a signal of a non-equivalent element. In the illustrated manner, it is possible to connect any number of solenoid valves, or rather of valve excitation windings, to one output A.
The OR-link 16 also reacts to leakage currents via the windings L1-L4. As the drop in voltage on the low-impedance resistor R2 is small, a relatively small leakage current flowing via any one of the windings will already cause the corresponding transistor T1-T4 to become current-carrying, thereby the drop in voltage on R2 being increased that much as to cause T5 and, hence, also T6 to become non-conductive. This again is detectable by means of a signal change at output A1 of the OR-link and, thus, at output A of the monitoring circuit, also.
Consequently, a certain signal variation at the output of the monitoring circuit 14 will correspond to the signal variation at the power transistors LT1, LT2 through LTn, or rather at the outputs of the microcontrollers 1, 2 (FIG. 1). The defect of any power transistor LT1 . . . LTn, an excessive saturation voltage, a short circuit or the like are consequently detectable by means of the monitoring circuit 14.
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This is a circuit configuration provided for an anti-lock-controlled brake system and serving for processing sensor signals obtained by wheel sensors (5) and for generating braking pressure control signals. This circuit configuration contains two microcontrollers (1, 2) interconnected by data exchange lines (7). The handled signals are concurrently processed by the microcontrollers independently of one another and the exchanged signals are checked for consistency. A deviation of the exchanged signals which is due to malfunctions is signalized to a safety circuit (8) which, thereupon, interrupts the power supply to the solenoid valves (Ll . . . Ln). The monitoring signal (WD1, WD2) fed to the safety circuit (8) is a predetermined alternating signal in case of consistency of the exchanged signals and in case of proper operation of the circuit configuration. The safety circuit (8) compares the alternating signal with a time standard derived from a clock generator (TG2, TG3) which is independent of the operating cycle (TG1) of the microcontrollers (1,2). A change in the alternating signal, as well as a failure in the time standard, causes a cut-off of power supply and, hence, of anti-lock control.
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FIELD OF THE INVENTION
The present invention relates generally to a remote network management system for remotely controlling network and computer equipment from one or more local user workstations through a remote control device. Specifically, a keyboard, video monitor, and cursor control device attached to a user workstation are utilized to remotely control domain servers, file/print servers, headless servers, network appliances, serial IT equipment, switches, routers, firewalls, security interfaces, application servers, load balancers, and environmental controls as their associated power supplies are connected to a remote control device.
BACKGROUND OF THE INVENTION
In many situations, it is desirable to manage networking equipment, servers, and computers located at a location remote from the system administrator. If the distance is great enough, the Internet is commonly utilized to control computers from a remote location. For example, a software program such as pcAnywhere may be utilized to access a remote computer over the Internet or a LAN utilizing the keyboard, video monitor, and cursor control device attached to a local user workstation. Remote computer access programs, such as pcAnywhere, typically require that host software is installed on the remote computer and client software is installed on the user workstation. To access a remote computer, a user of the user workstation selects the desired remote computer from a list and enters the appropriate username and password. Once access has been granted to the remote computer, the user utilizes the keyboard, video monitor, and cursor control device attached to the local user workstation to access and operate the remote computer.
Hardware solutions also exist for operating a remote computer from a user workstation over the Internet or via a modem. In contrast to software solutions, hardware solutions do not typically require host and/or client software. Instead, hardware solutions typically utilize a keyboard, video monitor, and mouse (“KVM”) switch which is accessible over the Internet or LAN via a common protocol, such as TCP/IP. The hardware solutions may also utilize a modem to connect to the Internet. Generally, a user or system administrator accesses the remote computers attached to the KVM switch utilizing an Internet web-browser or client software associated with the KVM switch. Once the remote computer has been selected, the remote computer's video signal is routed to the user workstation's video monitor and a user may then utilize a keyboard and/or mouse to control the remote computer. The KVM switch may additionally include a connection to the power source of the remote computer for a hard reboot in case of system failure.
The aforementioned hardware and software solutions generally utilize compression algorithms to reduce the necessary bandwidth required to transmit the video signals. For example, the remote network management system of the present invention uses the compression algorithm disclosed in application Ser. No. 10/233,299, which is incorporated herein by reference, to reduce and compress the digital data that must be transmitted to the remote computers and/or video display devices. Generally, video signals generated by a personal computer have both spatial and interframe redundancies. For example, in a near idle personal computer, the only change between successive frames of video might be the blinking of a cursor. Even as a user types a document, a majority of the screen does not change over a period of time. Hence, the compression algorithm used by the present invention takes advantage of these redundancies, both between successive frames of video and within each individual frame, to reduce the amount of digital video signal data that is transmitted to the remote computers and/or video display devices. Reducing the amount of digital data transmitted over the communication medium decreases communication time and decreases the required bandwidth.
Most forms of video compression known in the art require complicated calculations. For example, Moving Pictures Experts Group (“MPEG”) video compression algorithms use the discrete cosine transform as part of its algorithm. Also, the MPEG standard relies on the recognition of “motion” between frames, which requires calculation of motion vectors that describe how portions of the video image have changed over a period of time. Since these algorithms are calculation intensive, they either require expensive hardware or extended transmission times that allow sufficient time for slower hardware to complete the calculations.
In addition to complexity, many existing video compression techniques are lossy (i.e., they do not transmit all of the video signal information in order to reduce the required bandwidth). Typically, such lossy techniques either reduce the detail of a video image or reduce the number of colors utilized. Although reducing the number of colors could be part of an adequate compression solution for some computer management systems applications, in many other applications, such a result defeats the intended purposes of the computer management system.
The following references, which are discussed below, were found to relate to the field of computer management systems: Perholtz et al. U.S. Pat. No. 5,732,212 (“Perholtz”), Beasley U.S. Pat. No. 6,112,264 (“Beasley”), Pinkston, II et al. U.S. Pat. No. 6,378,009 (“Pinkston”), Thornton et al. U.S. Pat. No. 6,385,666 (“Thornton”), and Wilder et al. U.S. Pat. No. 6,557,170 (“Wilder”).
Perholtz discloses a method and apparatus for coupling a local user workstation, including a keyboard, mouse, and/or video monitor, to a remote computer. Perholtz discloses a system wherein the remote computer is selected from a menu displayed on a standard size personal computer video monitor. Upon selection of a remote computer by the system user, the remote computer's video signals are transmitted to the local user workstation's video monitor. The system user may also control the remote computer utilizing the local user workstation's keyboard and monitor. The Perholtz system is also capable of bi-directionally transmitting mouse and keyboard signals between the local user workstation and the remote computer. The remote computer and the local user workstation may be connected either via the Public Switched Telephone System (“PSTN”) and modems or via direct cabling.
Similar to Perholtz, Beasley discloses a specific implementation of a computerized switching system for coupling a local keyboard, mouse and/or video monitor to one of a plurality of remote computers. In particular, a first signal conditioning unit includes an on-screen programming circuit that displays a list of connected remote computers on the local video monitor. To activate the menu, a user depresses, for example, the “print screen” key on the local keyboard. The user selects the desired computer from the list using the local keyboard and/or mouse.
According to Beasley, the on-screen programming circuit requires at least two sets of tri-state buffers, a single on-screen processor, an internal synchronization generator, a synchronization switch, a synchronization polarizer, and overlay control logic. The first set of tri-state buffers couples the red, green, and blue components of the video signals received from the remote computer to the video monitor. That is, when the first set of tri-state buffers are energized, the red, green, and blue video signals are passed from the remote computer to the local video monitor through the tri-state buffers. When the first set of tri-state buffers are not active, the video signals from the remote computer are blocked. Similarly, the second set of tri-state buffers couples the outputs of the single on-screen processor to the video monitor. When the second set of tri-state buffers is energized, the video output of the on-screen programming circuit is displayed on the local video monitor. When the second set of tri-state buffers is not active, the video output from the on-screen programming circuit is blocked. Alternatively, if both sets of tri-state buffers are energized, the remote computer video signals are combined with the video signals generated by the on-screen processor prior to display on the local video monitor.
The on-screen programming circuit disclosed in Beasley also produces its own horizontal and vertical synchronization signals. To dictate which characters are displayed on the video monitor, the CPU sends instructional data to the on-screen processor. This causes the on-screen processor to retrieve characters from an internal video RAM for display on the local video monitor.
The overlaid video image produced by the on-screen processor, namely a Motorola MC141543 on-screen processor, is limited to the size and quantity of colors and characters that are available with the single on-screen processor. In other words, the Beasley system is designed to produce an overlaid video that is sized for a standard size computer monitor (i.e., not a wall-size or multiple monitor type video display) and is limited to the quantity of colors and characters provided by the single on-screen processor.
During operation of the Beasley system, a remote computer is chosen from the overlaid video display. Thereafter, the first signal conditioning unit receives keyboard and mouse signals from the local keyboard and mouse and generates a data packet for transmission to a central cross point switch. The cross point switch routes the data packet to the second signal conditioning unit, which is coupled to the selected remote computer. The second signal conditioning unit then routes the keyboard and mouse command signals to the keyboard and mouse connectors of the remote computer. Similarly, video signals produced by the remote computer are routed from the remote computer through the second signal conditioning unit, the cross point switch, and the first signal conditioning unit to the local video monitor. The horizontal and vertical synchronization video signals received from the remote computer are encoded on one of the red, green or blue video signals. This encoding reduces the quantity of cables required to transmit the video signals from the remote computer to the local video monitor.
Pinkston discloses a keyboard, video, mouse (“KVM”) switching system capable of coupling to a standard network (e.g., a Local Area Network) operating with a standard network protocol (e.g., Ethernet, TCP/IP, etc.). The system of Pinkston couples a central switch to a plurality of computers and at least one user station having a keyboard, video monitor, and mouse. The central switch includes a network interface card (“NIC”) for connecting the central switch to a network, which may include a number of additional computers or remote terminals. Utilizing the Pinkston system, a user located at a remote terminal attached to the network may control any of the computers coupled to the central switch.
Thornton discloses a computer system having remotely located I/O devices. The system of Thornton includes a computer, a first interface device, and a remotely located second interface device. The first interface device is coupled to the computer and the second interface device is coupled to a video monitor and as many as three I/O devices (e.g., keyboard, mouse, printer, joystick, trackball, etc.) such that a human interface is created. The first and second interface devices are coupled to each other via a four wire cable. The first interface device receives video signals from the connected computer and encodes the horizontal and vertical synchronization signals of the received video signals onto at least one of the red, green, and blue components of the video signal. The first interface device also encodes the I/O signals received from the connected computer into a data packet for transmission over the fourth wire in the four wire cable. Thereafter, the encoded, red, green, and blue components of the video signals and the data packet are transmitted to the second interface device located at the human interface. The second interface device decodes the encoded red, green, and blue components of the video signal, separates the encoded horizontal and vertical synchronization signals, and decodes the I/O signal data packet. The video signal and the synchronization signals are then output to the video monitor attached to the second interface and the decoded I/O signals are routed to the proper I/O device, also attached to the second interface. The second interface device may optionally include circuitry to encode I/O signals received from the I/O devices attached to the second interface for transmission to the first interface device.
Wilder discloses a keyboard, video, mouse, and power switching (“KVMP”) apparatus for connecting a plurality of computers to one or more user stations having an attached keyboard, video monitor, and mouse. On screen display (“OSD”) circuitry embedded within the KVMP switching apparatus allows a user located at a user station to select and operate any one of the computers utilizing the keyboard, video monitor, and mouse attached to the user station. Secondary switching circuitry located within the KVMP switching apparatus allows a user located at a user station to additionally control the electrical power supply supplying each computer.
In view of the foregoing, a need clearly exists for a self-contained remote network management system capable of operating and controlling networking equipment, servers, and computers connected to a remote control switching unit. Furthermore, such a system should allow a user to control the power supply attached to the remote networking equipment, servers, and computers. The system should aid in managing remote network environments, thereby reducing the need to have an on-site system administrator.
SUMMARY OF THE INVENTION
The present invention provides a self-contained remote network management system for administrating a remote computer networking environment from one or more local user workstations with attached peripheral devices (i.e., keyboard, video monitor, cursor control device, etc.). The remote network management system of the present invention allows a user located at a user workstation to access, operate, and control networking equipment, servers, and computers located at a remote location. The remote network management system also allows a user to control the power supply to each piece of remote equipment. The networking equipment (e.g., hubs, switches, routers, etc.) is typically controlled via a serial interface. In contrast, servers and computers are controlled and operated utilizing a keyboard, video monitor, and mouse.
The remote networking equipment, servers, and computers are all connected to a central remote management unit (“RMU”), and in turn, the RMU is connected to the Internet or a LAN via an Ethernet or modem connection. The RMU has serial ports for connection to the networking equipment as well as keyboard, video, and cursor control device ports for connection to the servers and computers. The RMU additionally contains a port for connection to a power supply capable of controlling the power to the networking equipment, servers, and computers. Standard cabling is utilized to connect the networking equipment, servers, and computers to the appropriate ports on the RMU.
The RMU also provides compatibility between various operating systems and/or communication protocols, including but not limited to, those manufactured by Microsoft Corporation (“Microsoft”) (Windows), Apple Computer, Inc. (“Apple”) (Macintosh), Sun Microsystems, Inc. (“Sun”) (Solaris), Digital Equipment Corporation (“DEC”), Compaq Computer Corporation (“Compaq”) (Alpha), International Business Machines (“IBM”) (RS/6000), Hewlett-Packard Company (“HP”) (HP9000) and SGI (formerly “Silicon Graphics, Inc.”) (IRIX).
To utilize the remote network management system of the present invention, a user first initiates a management session by utilizing client software located on a user workstation to connect to the RMU. Alternatively, the user may utilize an Internet browser to connect to the RMU. The user is then prompted by the RMU to provide a user name and a password. The RMU is capable of storing multiple profiles and different levels of access for each profile. Once a user has been authenticated, the user is provided an option menu on the user workstation's monitor produced by option menu circuitry located in the RMU. The option menu consists of a menu listing all the networking equipment, servers, and computers at the remote location. The option menu additionally contains a menu allowing a user to control the power to each piece of remote equipment. The user selects the desired networking equipment, server, or computer by utilizing the keyboard and/or cursor control device attached to the user workstation. Once a user makes a selection, the user is provided access to the remote equipment as if the user is physically located at the remote site.
The RMU and the user workstation communicate via TCP/IP. Before transmission via TCP/IP, the unidirectional video signals (i.e., from the RMU to the user workstation) are digitized by a frame grabber. This circuit captures video output from the initiating computer at a speed of at least 20 frames/second and converts the captured analog video signals to a digital representation of pixels. Each pixel is digitally represented with 5 bits for red, 5 bits for green, and 5 bits for blue. The digital representation is then stored in a raw frame buffer. The compression algorithm then processes the digital data contained in the raw frame buffer. The compression algorithm is actually a combination of four sub-algorithms (i.e., the Noise Reduction and Difference Test (“NRDT”), Smoothing, Caching, and Bit Splicing/Compression sub-algorithms) as described in greater detail below.
After the video signals have arrived at the user workstation, decompression occurs. The user workstation operates as a decompression device by executing a decompression algorithm. Along with any transmitted video or data signals, the RMU transmits messages to the decompression devices regarding the portions of the video that yielded “cache” hits (i.e., portions of unchanged video). In response, the decompression device constructs the video frame based upon the transmitted video signals and the blocks of pixels contained in its local cache. Also, the decompression device updates its local cache with the new blocks of pixels received from the RMU. In this manner, the decompression device caches remain synchronized with the compression device cache. Both the compression device and the decompression device update their respective cache by replacing older video data with newer video data.
Furthermore, the video signals transmitted by the RMU have been compressed using a lossless compression algorithm. Therefore, the decompression device (e.g., software on the user workstation) must reverse this lossless compression. This is done by identifying the changed portions of the video image, based upon flags transmitted by the RMU. From this flag information, the decompression device is able to reconstruct full frames of video.
In addition, the decompression device converts the video frame to its original color scheme by reversing a color code table (“CCT”) conversion. The decompression device, like the RMU, locally stores a copy of the same CCT used to compress the video data. The CCT is then used to convert the video data received from the RMU to a standard RGB format that may be displayed on the monitor attached to the user workstation.
The decompression algorithm can be implemented in the remote network management system of the present invention in a variety of embodiments. For example, in one embodiment, it can be implemented as a software application that is executed by the user workstation. In an alternate embodiment, the decompression algorithm can be implemented to execute within a web browser such as Internet Explorer or Netscape® Navigator®. Such an embodiment eliminates the need for installation of application specific software on the user workstation. Also, this embodiment allows the RMU to easily transmit the video signals to any user workstation with Internet capabilities, regardless of the distance at which the computer is located from the initiating computer. This feature reduces the cabling cost associated with the remote network management system of the present invention.
Since the present invention can be used to display video signals at locations that may be at a great distance from the RMU, it is important to ensure that the video signal transmission is secure. If the transmission is not secure, hackers, competitors, or other unauthorized users could potentially view confidential information contained within the video signals. Therefore, the remote network management system of the present invention is designed to easily integrate with digital encryption techniques known in the art. In one embodiment of the present invention, a 128-bit encryption technique is used both to verify the identity of the RMU and to encrypt and decrypt the transmitted video and data signals. In this embodiment, a 128-bit public key RSA encryption technique is used to verify the remote participant, and a 128-bit RC4 private key encryption is used to encrypt and decrypt the transmitted signals. Of course, other encryption techniques or security measures may be used.
Finally, since the remote network management system of the present invention allows for platform independent communications, the compression algorithm utilized does not employ operating system specific hooks, nor does it use platform specific GDI calls.
In the preferred embodiment, the compression algorithm described herein and in co-pending application Ser. No. 10/233,299 is used to transmit the video signals. However, the video transmission system is not limited to such an embodiment. Rather, this system may be employed with any compression algorithm without departing from the spirit of the invention.
Therefore, it is an object of the present invention to provide an improved, remote network management system that enables a user to control a remote networking environment from one or more local user workstations. Such a remote networking environment may include domain servers, file/print servers, headless servers, network appliances, serial IT equipment, switches, routers, firewalls, security interfaces, application servers, load balancers, and environmental controls.
Further, it is an object of the present invention to provide a remote network management system that allows one or more local user workstations to access and operate remote networking equipment, servers, and computers connected to a remote management unit.
It is another object of the present invention to provide a single, platform-independent remote network management system offering centralized, integrated, and secure control.
It is an additional object of the present invention to provide a network-independent remote network management system containing a modem for emergency access.
It is a further object of the present invention to provide a remote network management system capable of BIOS-level control of KVM equipment and console-level control of serial devices.
Additionally, it is an object of the present invention to provide a remote network management system which provides a single consolidated view of all servers and other connected devices from one screen via a web browser.
It is another object of the present invention to provide a remote network management system which contains a single sign-on and interface.
Additionally, it is an object of the present invention to provide a remote network management system which is upgradeable.
It is a further object of the present invention to provide a remote network management system which provides high performance over low bandwidth connections including modem, wireless, cable, DSL, and fractional T1.
It is another object of the present invention to provide a remote network management system which utilizes a video compression algorithm and frame-grabber technology to ensure the fastest possible transmission of high quality video.
Furthermore, it is an object of the present invention to provide a remote network management system including built-in serial port buffering to provide views of recent console history.
It is still a further object of the present invention to provide a remote network management system that is easy to install and operate.
In addition, it is an object of the present invention to provide a remote network management system that is compact and provides readily accessible communications ports.
Further, it is an object of present invention to provide a remote network management system, which allows error-free communications between peripheral devices of a local user workstation and networking equipment, servers, and computers located at domain servers, file/print servers, headless servers, network appliances, serial IT equipment, switches, routers, firewalls, security interfaces, application servers, load balancers, and environmental controls.
It is also an object of the present invention to provide a remote network management system capable of controlling the power supply to remotely located networking equipment, servers, and computers.
Other objects, features, and characteristics of the present invention, as well as the methods of operation and functions of the related elements of the structure, and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following detailed description with reference to the accompanying drawings, all of which form a part of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
A further understanding of the present invention can be obtained by reference to a preferred embodiment set forth in the illustrations of the accompanying drawings. Although the illustrated embodiment is merely exemplary of systems for carrying out the present invention, both the organization and method of operation of the invention, in general, together with further objectives and advantages thereof, may be more easily understood by reference to the drawings and the following description. The drawings are not intended to limit the scope of this invention, which is set forth with particularity in the claims as appended or as subsequently amended, but merely to clarify and exemplify the invention.
For a more complete understanding of the present invention, reference is now made to the following drawings in which:
FIG. 1 is a schematic representation of a remote network management system according to the preferred embodiment of the invention illustrating the connection of a user workstation that includes a keyboard, video monitor, and cursor control device to networking equipment, servers, and computers through a remote management unit (“RMU”).
FIG. 2 is a screen-shot of an example option menu utilized to control the networking equipment, servers and computers.
FIG. 3A is a block diagram of the preferred embodiment of the RMU shown in FIG. 1 according to the preferred embodiment of the present invention illustrating the internal structure of the RMU and connectors for serial devices, keyboards, video monitors, cursor control devices, and a power supply.
FIG. 3B is a detailed block diagram of the serial card shown in FIG. 3A .
FIG. 3C is a detailed block diagram of the KVM port header shown in FIG. 3A .
FIG. 3D is a detailed block diagram of the video processor shown in FIG. 3A .
FIG. 4 depicts a flowchart of the compression algorithm utilized by the preferred embodiment of the RMU in accordance with the present invention.
FIG. 5A depicts a flowchart detailing the Noise Reduction and Difference Test and smoothing sub-algorithms of the compression algorithm utilized by the preferred embodiment of the present invention.
FIG. 5B depicts a flowchart that details the caching and bit splicing/compression sub-algorithms of the compression algorithm utilized by the preferred embodiment of the present invention.
FIG. 6 depicts a flowchart that details the nearest match function and its integration with the CCT of the compression algorithm utilized by the preferred embodiment of the present invention.
FIG. 7 depicts a flowchart that details the Noise Reduction and Difference Test sub-algorithm of the compression algorithm utilized by the preferred embodiment of the present invention.
FIG. 8 depicts an example application of the Noise Reduction and Difference Test sub-algorithm to a sample block of pixels as performed by the compression algorithm utilized by the preferred embodiment of the present invention.
FIG. 9 depicts a detailed flowchart of the operation of the decompression algorithm used by the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As required, a detailed illustrative embodiment of the present invention is disclosed herein. However, techniques, systems and operating structures in accordance with the present invention may be embodied in a wide variety of forms and modes, some of which may be quite different from those in the disclosed embodiment. Consequently, the specific structural and functional details disclosed herein are merely representative, yet in that regard, they are deemed to afford the best embodiment for purposes of disclosure and to provide a basis for the claims herein which define the scope of the present invention. The following presents a detailed description of the preferred embodiment (as well as some alternative embodiments) of the present invention.
Referring first to FIG. 1 , depicted is the architecture of the preferred embodiment of a remote network management system in accordance with the present invention. Specifically, a remote network management system is shown comprising user workstation 101 including keyboard 103 , video monitor 105 , and cursor control device 107 , remote management unit (“RMU”) 109 , Internet/LAN/WAN 108 , public switched telephone network (“PSTN”) 106 , serial devices 111 a and 111 b , servers 113 a and 113 b , remote computers 115 a and 115 b , and power supply 117 . Preferably, user workstation 101 and RMU 109 are connected to Internet/LAN/WAN 108 via communication lines 119 and 121 , respectively. Although CAT 5 cabling is the preferred cabling for communication lines 119 and 121 , other cabling may be used, such as coaxial, fiber optic or multiple CAT 5 cables. CAT 5 cabling is preferred because it reduces cabling cost while maintaining the strength of signals that are transmitted over an extended distance. Alternatively, wireless networking equipment may also be utilized to connect RMU 109 to Internet/LAN/WAN 108 and serial devices 111 a and 111 b , servers 113 a and 113 b , computers 115 a and 115 b , and power supply 117 . Similarly, wireless networking equipment may also be utilized to connect user workstation 101 to Internet/LAN/WAN 108 .
In an alternate embodiment, user workstation 101 may utilize PSTN 106 to connect to RMU 109 . If PSTN 109 is utilized to connect to RMU 109 , communication lines 120 and 122 would preferably be CAT 3 cables. As an example, this means of communication may be utilized in emergency situations, such as if Internet/LAN/WAN 108 is not functioning properly.
Communication lines 119 and 121 are connected to user workstation 101 and RMU 109 by plugging each end into a RJ-45 socket located on the respective pieces of equipment to be coupled by the CAT 5 cable. Although RJ-45 sockets and plugs are preferred, other types of connector may be used, including but not limited to RJ-11, RG-58, RG-59, British Naval Connector (“BNC”), and ST connectors.
The remote management system includes local user workstation 101 , preferably comprising dedicated peripheral devices such as keyboard 103 , video monitor 105 and/or cursor control device 107 . Other peripheral devices may also be located at workstation 101 , such as a printer, scanner, video camera, biometric scanning device, microphone, etc. Each peripheral device is directly or indirectly connected to user workstation 101 , which is attached to Internet/LAN/WAN 108 via communication line 119 . Of course, wireless peripheral devices may also be used with this system. In a preferred mode of operation, all electronic signals (i.e., keyboard signals and cursor control device signals) received at user workstation 101 from attached peripheral devices are transmitted to Internet/LAN/WAN 108 via communication line 119 . Thereafter, the signals are transmitted to RMU 109 via communication line 121 . RMU transmits the received signals to the respective remote equipment, which, in this figure, includes serial devices 111 a and 111 b , servers 113 a and 113 b , computers 115 a and 115 b , and power supply 117 .
RMU 109 may be compatible with all commonly used, present day computer operating systems and protocols, including, but not limited to, those manufactured by Microsoft (Windows), Apple (Macintosh), Sun (Solaris), DEC, Compaq (Alpha), IBM (RS/6000), HP (HP9000) and SGI (IRIX). Additionally, local devices may communicate with remote computers via a variety of protocols including Universal Serial Bus (“USB”), American Standard Code for Information Interchange (“ASCII”) and Recommend Standard-232 (“RS-232”).
Serial devices 113 a and 113 b are connected to RMU 109 via communication lines 112 a and 112 b , respectively. Preferably, communication lines 112 a and 112 b are CAT 5 cables terminated with RJ-45 connectors. However, a special adapter may be required to properly connect communication lines 112 a and 112 b to serial devices 111 a and 111 b since not all serial devices are outfitted with RJ-45 ports. For example, if serial device 111 a only contained a serial port, the adapter would interface the RJ-45 connector of communication line 112 a to the serial port located on serial device 111 a.
Similarly, power supply 117 is connected to RMU 109 via communication line 118 . Preferably, communication line 118 is a CAT 5 cable terminated with an RJ-45 connector on each end.
Servers 113 a and 113 b and computers 115 a and 115 b are connected to RMU 109 via communication lines 114 a , 114 b , 116 a , and 116 b , respectively. Preferably, communication lines 114 a , 114 b , 116 a , and 116 b are three-to-one coaxial cables which allow the keyboard, video, and cursor control device ports of servers 113 a and 113 b and computers 115 a and 115 b to be connected to a single port on RMU 109 as shown.
To connect to the remote networking environment for administration and access, a user initiates a remote management session at user workstation 101 . The user first accesses client software located using workstation 101 , which prompts the user for a user name and password. However, the system may utilize any combination of identification data to identify and/or authenticate a particular user. Utilizing the attached keyboard 103 , cursor control device 107 or other peripheral device, the user enters the user name and password. Once the user name and password have been entered, user workstation 101 connects to Internet/LAN/WAN 108 via communication line 119 . User workstation 101 may connect to Internet/LAN/WAN 108 in a variety of ways. For example, user workstation 101 may be connected to Internet/LAN/WAN 108 through an Ethernet connection. In this example, communication line 119 would be a CAT 5 cable. The connection to Internet/LAN/WAN 108 may also be accomplished through a wireless connection which precludes the need for communication line 119 . For example, RMU 109 may utilize standard Wireless Fidelity (“Wi-Fi”) networking equipment to communicate with Internet/LAN/WAN 108 .
Alternatively, user workstation 101 may connect to RMU 109 via PSTN 106 by utilizing a modem connection. In this alternative example, communication lines 120 and 122 would be CAT 3 cables.
The username and password are then routed through Internet/LAN/WAN 108 to RMU 109 via communication line 121 . RMU 109 receives the username and password and authenticates the user located at user workstation 101 . Once the user has been authenticated by RMU 109 , an option menu circuit located in RMU 109 provides an option menu to user 101 via monitor 105 listing all the devices accessible through RMU 109 . The user makes selections from this option menu utilizing keyboard 103 , cursor control device 105 , or some other peripheral device attached to user workstation 101 .
As shown in FIG. 2 , option menu 201 consists of device list 203 , first desktop window 205 , power control window 207 , second desktop window 209 , and serial device window 211 . Device list 203 lists all active and inactive devices connected to RMU 109 . A user utilizes this menu to select the desired device for control. In this example, first desktop window 205 displays the desktop of one of the remote computers. By selecting first desktop window 205 , a user may utilize keyboard 103 , cursor control device 107 , or some other peripheral device to control the displayed remote computer. In a similar manner, a user may utilize power control window 207 to access and operate power supply 117 . Power control window 207 displays a list of all devices connected to power supply 117 as well as the status of each attached device such as average power utilized, RMS current, RMS voltage, internal temperature, etc. Power control window 207 is primarily utilized to cycle the power to the devices attached to power supply 117 . However, since power supply 117 is programmable, power control window 207 may be utilized to perform any functions possible with power supply 117 .
Second desktop window 209 is utilized to access and operate a second remote computer or server. Serial device window 211 is utilized to operate and access any remote serial device attached to remote management unit 109 . Serial device window 211 displays the current output produced by the serial device as well as the previous output produced by the serial device. The previous output of the serial device is stored in a buffer located in RMU 109 .
Preferably, option menu 201 consists of a menu in which the attached devices are arranged by their connection to RMU 109 . For example, serial devices 111 a and 111 b preferably would be listed in a menu different from servers 113 a and 113 b and computers 115 a and 115 b . The option menu also consists of a sub-menu for controlling power supply 117 .
RMU 109 may additionally contain an attached keyboard 123 , cursor control device 125 , and video monitor 127 which allow a user local to RMU 109 to control the attached serial devices 111 a and 111 b , servers 113 a and 113 b , and computers 115 a and 115 b , power supply 117 , etc. Keyboard 123 , cursor control device 125 , and video monitor 127 may also be utilized to configure RMU 109 locally. Keyboard 123 , cursor control device 125 , and video monitor 127 are connected to RMU 109 via interface cable 129 . Alternatively, keyboard 123 , cursor control device 125 , and video monitor 127 may be connected to RMU 109 via standard keyboard, cursor control device, and video monitor connectors.
Referring next to FIG. 3A , depicted is the preferred embodiment of RMU 109 according to the present invention. Keyboard and mouse signals arrive at RJ-45 port 201 from Internet/LAN/WAN 108 via communication line 121 . RMU 109 consists of RJ-45 port 201 , RJ-11 port 202 , Ethernet connector 205 , modem module 204 , communications port connector 206 , CPU 207 , communications port connector 208 , PCI riser card 209 , serial card 211 , video processor 212 , serial ports 213 , frame grabber 215 , KVM port header 217 , KVM ports 219 , power supply 221 , power port 223 , reset circuitry 225 , local KVM port 227 , and option menu circuit 229 . As shown, the keyboard and/or cursor control device signals initially arrive at RJ-45 port 201 if RMU 109 is connected to Internet/LAN/WAN 108 via an Ethernet connection. The signals are then transmitted to Ethernet connector 205 which depacketizes the signals. Alternatively, the signals may arrive from PSTN 106 at RJ-11 port 202 if the keyboard and/or cursor control device signals were transmitted via a modem. In this case, the signals are transmitted to modem module 204 , which demodulates the received signals, and subsequently to communications port connector 206 which depacketizes the signals.
From Ethernet connector 205 or communications port connector 206 , the keyboard and/or cursor control device signals are then transmitted to CPU 207 via video processor 212 . CPU 207 utilizes routing information contained within the keyboard and/or cursor control device signals to determine the proper destination for the keyboard and cursor control device signals. If the keyboard and cursor control device signals specify a command to power supply 117 , CPU 207 interprets the received command (e.g., utilizing a look-up table) and sends the proper command to power supply 117 via communications port connector 208 and power port 210 . Preferably, power port 210 is an RJ-45 connector to allow the RMU to interface with a power strip and control it as if it were a serial device.
If CPU 207 determines that the keyboard and cursor control device signals contain a serial device routing instruction, the keyboard and cursor control device signals are transmitted to serial card 211 through PCI riser card 209 . As shown in FIG. 3B , serial port 211 consists of UART/switch 301 , serial transceivers 303 , and programmable memory 305 . Serial card 211 is capable of bidirectional signal transmission. When keyboard and/or cursor control device signals are being transmitted from PCI riser card 209 to serial port 213 , the signals are initially transmitted to UART/switch 301 which, utilizing data and logic stored in memory 305 , determines the proper serial transceiver 303 to which the keyboard and/or cursor control device signals are to be sent. In the preferred embodiment of serial card 211 , UART/switch 301 is an EXAR XR17c158. Subsequently, the analog signals are transmitted to the appropriate serial transceiver 303 which converts the signals from a parallel format to a serial format. Serial transceiver 303 is preferably a HIN23E serial transceiver from Intersil. The keyboard and/or cursor control device signals are then transmitted to serial port 213 .
In contrast, when commands from serial device 111 a or 111 b are transmitted to CPU 207 via serial port 213 , serial card 211 , and PCI riser card 209 , the commands are initially transmitted to serial transceiver 303 which converts the serial commands to a parallel format. Subsequently, the commands are transmitted to UART/switch 301 which re-transmits the commands to CPU 207 via PCI riser card 209 . CPU 207 interprets the received commands and emulates a virtual terminal for display on video monitor 105 . The present invention may incorporate any number of serial ports 213 . In the example shown in FIG. 3A , two serial devices, 111 a and 111 b , are connected to serial ports 213 a and 213 b , respectively.
If CPU 207 determines that the keyboard and/or cursor control device signals are meant for servers 113 a and 113 b or computers 115 a and 115 b , CPU 207 transmits the keyboard and cursor control device signals through PCI riser card 209 and frame grabber 215 to KVM port header 217 which transmits the signals to the appropriate KVM port 219 . As shown in FIG. 3C , KVM port header 217 consists of switch 350 , video switch 352 , and UARTs 354 . When keyboard and/or cursor control device signals are transmitted from KVM port 219 to KVM port header 217 , the signals are initially received at UART 354 . UART 354 converts the received serial keyboard and/or cursor control device signals to a parallel format. The converted keyboard and/or cursor control device signals are then transmitted to switch 350 which retransmits the signals to frame grabber 215 .
In a similar manner, bi-directional keyboard and/or cursor control device signals are also transmitted from frame grabber 215 to KVM port 219 . Keyboard and/or cursor control device signals received from frame grabber 215 are transmitted to switch 350 located in KVM port header 217 . Utilizing control signals contained within the keyboard and/or cursor control device signals, switch 350 transmits the received keyboard and/or cursor control device signals to the appropriate UART 354 . UART 354 then converts the keyboard and/or cursor control device signals from a parallel format to a serial format for transmission to KVM port 219 .
KVM port header 217 also transmits uni-directional video signals received at KVM port 219 to frame grabber 215 . The analog video signals received from KVM port 219 initially are transmitted to video switch 352 . Video switch 352 then retransmits the video signals to frame grabber 215 which converts the received analog video signals to a digital format.
Turning to FIG. 3D , after the video signals have been digitized by frame grabber 215 , the digitized video signals are transmitted to video processor 212 via CPU 207 . Video processor 212 consists of video-in port 370 , R-out 376 a , G-out 376 b , B-out 376 c , pixel pusher 378 , frame buffers 380 , compression device 382 , flash memory 384 , RAM 386 , microprocessor 388 , and switch 390 . Shown at the top of FIG. 3D , video-in port 370 receives the digitized video signals from CPU 207 . The outputs of video-in port 370 are shown as R-out 376 a , G-out 376 b , and B-out 376 c , which represent the red component, green component, and blue component of the digitized video signal, respectively. Video-in port 370 outputs these digitized video signal components in the form of pixels, which are transmitted to and stored in pixel pusher 378 . Pixel pusher 378 , flash memory 384 , and Random Access Memory (“RAM”) 386 communicate with microprocessor 388 via communication bus 387 . Pixel pusher 378 also communicates with frame buffers 380 (e.g., raw frame buffer, compare frame buffer, etc.) and compression device 382 via communication buses 379 and 381 , respectively. The compression algorithm is executed by microprocessor 388 . Generally, the compression operates as follows:
Noise Reduction and Difference Test:
As discussed above, digitization of the analog video signals is necessary to allow these signals to be transmitted via a digital communication medium (e.g., a network, LAN, WAN, Internet, etc.). However, a detrimental side effect of the digitization process is the introduction of quantization errors and noise into the video signals. Therefore, the Noise Reduction and Difference Test sub-algorithm (“NRDT sub-algorithm”) is designed to reduce the noise introduced during the digitization of the video signals. In addition, the NRDT sub-algorithm simultaneously determines the differences between the recently captured frame of video (i.e., the “current frame”) and the previously captured frame of video (i.e., the “compare frame”).
First, the NRDT sub-algorithm divides the current frame, which is contained in the raw frame buffer, into 64×32 blocks of pixels. Alternatively, other sizes of blocks may be used (e.g., 8×8 pixels, 16×16 pixels, 32×32 pixels, etc.) based upon criteria such as the size of the entire video frame, the bandwidth of the communication medium, desired compression yield, etc.
After the current frame is divided into blocks, a two-level threshold model is applied to the block of pixels to determine whether it has changed with respect to the compare frame. These two thresholds are the “pixel threshold” and the “block threshold.”
First, a given pixel is examined and the value of each of the three colors (i.e., red, green, and blue) of the pixel is calculated with the value of its corresponding pixel in the compare frame. From this calculation, a distance value is computed. If the distance value is greater than the pixel threshold (i.e., the first threshold of the two-level threshold), this distance value is added to a distance sum. This process is performed for each pixel in the block.
Next, after the distance value of all of the pixels in the block have been calculated and processed in the aforementioned manner, the resulting value of the distance sum is compared to the block threshold (i.e., the second threshold of the two-level threshold). If the distance sum exceeds the block threshold, then this block of pixels is considered changed in comparison to the corresponding block of pixels in the compare frame. If a change is determined, the compare frame, which is stored in the compare frame buffer, will be updated with the new block of pixels. Furthermore, the new block of pixels will be further processed and transmitted in a compressed format to the user workstation.
In contrast, if the distance sum is not greater than the block threshold, the block of pixels is determined to be unchanged. Consequently, the compare frame buffer is not updated, and this block of pixels is not transmitted to the user workstation. Eliminating the transmission of unchanged blocks of pixels reduces the overall quantity of data to be transmitted, thereby increasing transmission time and decreasing the required bandwidth.
The NRDT sub-algorithm is ideal for locating both a large change in a small quantity of pixels and a small change in a large quantity of pixels. Consequently, the NRDT sub-algorithm is more efficient and more accurate than known percentage threshold algorithms that simply count the number of changed pixels in a block of pixels. With such an algorithm, if a few pixels within the block of pixels have changed drastically (e.g., from black to white), the algorithm would consider the block of pixels to be unchanged since the total number of changed pixels would not exceed the percentage threshold value. This result will often lead to display errors in the transmission of computer video.
Consider, for example, a user that is editing a document. If the user were to change a single letter, such as changing an “E” to an “F”, only a few pixels of the video image would change. However, based upon this change, the resulting document is dramatically different than the original document. A percentage threshold algorithm would not register this change and, therefore, would lead to a display error. A percentage threshold algorithm, by only looking at the number of pixels within a block that have changed, generally fails to recognize a video image change in which a few pixels have changed substantially. However, the NRDT sub-algorithm used by the present invention, by virtue of its two-level threshold, will recognize that such a block of pixels has significantly changed between successive frames of video.
Smoothing:
When the NRDT sub-algorithm determines that a block of pixels has changed, the digital data that represents this block is further processed by a smoothing sub-algorithm. This sub-algorithm reduces the noise introduced during the analog-to-digital conversion.
First, each digital pixel representation is converted to a representation that uses a lower quantity of bits for each pixel. It is known in the art to compress color video by using a fewer number of bits to represent each color of each pixel. For example, a common video standard uses 8 bits to represent each of the red, green, and blue components of a video signal. Because 24 total bits are used to represent a pixel, this representation is commonly referred to as “24 bit RGB representation”. If only the four most significant bits of the red, green, and blue components of the pixel are used to represent its color in lieu of all eight bits, the size of the data used to represent the block of pixels, and thus a frame of video, is reduced by fifty percent.
This method of compression is simple and generally degrades the quality of the video. In contradistinction, the smoothing sub-algorithm of the present invention incorporates a more intelligent method of compression. This method uses a Color Code Table (“CCT”) to map specific RGB representations to more compact RGB representations. Both the compression and decompression algorithms of the present invention use the same CCT. However, different color code tables may be chosen depending on the available bandwidth, the capabilities of the local display device, etc.
For each block of pixels, a histogram of pixel values is created and sorted by frequency such that the smoothing sub-algorithm may determine how often each pixel value occurs. Pixel values that occur less frequently are compared to pixel values that occur more frequently. To determine how similar pixel values are, a distance value is calculated based upon the color values of the red, green, and blue (“RGB”) components of each pixel. During the histogram analysis, a map of RGB values to color codes (i.e., a CCT) is created. If a less frequently occurring pixel value needs to be adjusted to a similar, more frequently occurring pixel value, the CCT is used to map the less frequently occurring pixel value to the color code of the more frequently occurring pixel value. Thus, the noise is efficiently removed from each block and the number of bits used to represent each pixel is reduced.
For illustrative purposes, suppose that an 8×8 pixel block is being processed. Further suppose that of the 64 pixels in the current block, 59 are blue, 4 are red, and 1 is light blue. Further assume that a low frequency threshold of 5 and a high frequency threshold of 25 are used. In other words, if a pixel value occurs less than 5 times within a block, it is considered to have a low frequency. Similarly, if a pixel value occurs more than 25 times within a block, it is considered to have a high frequency. In the preferred embodiment of the present invention, the smoothing sub-algorithm ignores pixel values occurring between these two thresholds. Therefore, in the present example, the smoothing sub-algorithm determines that the red and light blue pixels occur with low frequency, and the blue pixels occur with high frequency.
In the next step, the values of the 4 red pixels and the 1 light blue pixel are compared with the value of the 59 blue pixels. In this step, a pre-determined distance threshold is used. If the distance between the less frequent pixel value and the more frequent pixel value is within this distance threshold, then the less frequent pixel value is converted to the more frequent pixel value. Therefore, in our present example, it is likely that the light blue pixel is close enough in value to the blue pixel that its distance is less than the distance threshold. Consequently, the light blue pixel is mapped to the blue pixel. In contrast, it is likely that the distance between the red and blue pixels exceeds the distance threshold and, therefore, the red pixel is not mapped to the blue pixel. With the smoothing sub-algorithm of the present invention, although the red pixels occur rarely, the distance between the red pixel value and the blue pixel value is large enough that the red pixels are not converted to blue pixels. In this manner, the smoothing sub-algorithm of the present invention increases the redundancy in compared images by eliminating changes caused by superfluous noise introduced during the analog-to-digital conversion while retaining real changes in the video image.
Caching:
After the smoothing sub-algorithm has been applied to the digital video image data, an optional caching sub-algorithm may be applied to further minimize the bandwidth required for transmitting the video images. The caching sub-algorithm uses a cache of previously transmitted blocks of pixels. Similar to the NRDT sub-algorithm, the caching sub-algorithm is performed on a block of pixels within the video frame. Again, any block size may be used (e.g., 8×8, 16×16, 32×32 or 64×32).
First, the caching sub-algorithm performs a cache check, which compares the current block of pixels with blocks of pixels stored in the cache. The size of the cache may be arbitrarily large. Large caches generally yield a higher percentage of “cache hits.” However, memory and hardware requirements increase when the size of the cache is increased. Furthermore, the number of comparisons, and thus the processing power requirements, also increases when the size of the cache increases.
A “cache hit” occurs when a matching block of pixels is located within the cache. A “cache miss” occurs if a matching block of pixels is not found in the cache. When a cache hit occurs, the new block of pixels does not have to be retransmitted. Instead, a message and a cache entry identification (“ID”) are sent to the remote participant equipment. Generally, this message and cache entry ID will consume less bandwidth than that required to transmit an entire block of pixels.
If a “cache miss” occurs, the new block of pixels is compressed and transmitted to the user workstation. Also, both the RMU and user workstation update their respective cache by storing the new block of pixels in the cache. Since the cache is of limited size, older data is overwritten. One skilled in the art is aware that various algorithms can be used to decide which older data should be overwritten. For example, a simple algorithm can be employed to overwrite the oldest block of pixels within the cache, wherein the oldest block is defined as the least recently transmitted block.
In order to search for a cache hit, the new block of pixels must be compared with all corresponding blocks of pixels located within the cache. There are several ways in which this may be performed. In one embodiment, a cyclic redundancy check (“CRC”) is computed for the new block of pixels and all corresponding blocks of pixels. The CRC is similar to a hash code for the block. A hash code is a smaller, yet unique, representation of a larger data source. Thus, if the CRCs are unique, the cache check process can compare CRCs for a match instead of comparing the whole block of pixels. If the CRC of the current block of pixels matches the CRC of any of the blocks of pixels in the cache, a “cache hit” has been found. Because the CRC is a smaller representation of the block, less processing power is needed to compare CRCs. Furthermore, it is possible to construct a cache in which only the CRCs of blocks of pixels are stored at the remote participant locations. Thus, comparing the CRCs in lieu of comparing a full block of pixels saves processor time and thus improves performance.
Bit Splicing/Compression:
Once the NRDT, smoothing, and optional caching sub-algorithms are performed, each block of pixels that must be transmitted is compressed. In the preferred embodiment of the present invention, each block is compressed using the Joint Bi-level Image Group (“JBIG”) lossless compression algorithm.
The JBIG compression algorithm was designed for black and white images, such as those transmitted by facsimile machines. However, the compression algorithm utilized by the present invention can compress and transmit color video images. Therefore, when utilizing the JBIG compression algorithm, the color video image must be bit-sliced, and the resulting bit-planes must be compressed separately.
A bit plane of a color video image is created by extracting a single bit from each pixel color value in the color video image. For example, if 8 bits are used to represent the color of the pixel, then the color video image is divided into 8 bit planes. The compression algorithm, in conjunction with the CCT discussed above, transmits the bit plane containing the most significant bits first, the bit plane containing the second most significant bits second, etc. The CCT is designed such that the most significant bits of each pixel color are stored first and the lesser significant bits are stored last. Consequently, the bit planes transmitted first will always contain the most significant data, and the bit planes transmitted last will always contain the least significant data. Thus, the remote video monitor will receive video from the RMU progressively, receiving and displaying the most significant bits of the image before receiving the remaining bits. Such a method is less sensitive to changes in bandwidth and will allow a user to see the frame of video as it is transmitted, rather than waiting for all details of the frame to be sent.
After compression of the video signals is complete, the resulting video signals are transmitted to either Ethernet connector 205 or communications port connector 206 via switch 390 .
Referring back to FIG. 3A , RMU 109 also contains a power supply 221 which provides power to RMU 109 . Preferably, power supply 221 is a redundant power supply which contains backup circuitry in case the main circuitry fails. Power supply 221 receives power through power port 223 from an external power supply. The power to RMU is controlled by reset circuitry 225 which is interfaced directly to CPU 207 . Reset circuitry 225 is utilized to turn the power on/off and reset RMU 109 .
RMU 109 also contains local KVM port 227 interfaced to CPU 207 . Local KVM port 227 allows for connection of local keyboard 123 , video monitor 127 , and cursor control device 125 to RMU 227 via cable 129 ( FIG. 1 ). Local keyboard 123 , video monitor 127 , and cursor control device 125 may be utilized for onsite control of the attached serial devices 111 a and 111 b , servers 113 a and 113 b , computers 115 a and 115 b , and power supply 117 .
Option menu circuit 229 , under control of CPU 207 , provides the option menu to a user of the present invention. As previously discussed, the option menu contains menus for selecting a serial device, a remote server or computer, or options to control the power to all devices connected to power supply 117 .
To utilize the system of the present invention, a user first initiates a remote management session at user workstation 101 and enters the required username and password. However, any unique combination of authentication information may be utilized. User workstation 101 packetizes the entered information and routes it to Internet/LAN/WAN 108 via communication line 119 and then to RMU 109 via communication line 121 . The entered data is received at CPU 207 via RJ-45 connector 201 (or alternatively RJ-11 connector 202 ). Ethernet connector 205 removes the network protocol and transmits the received keyboard and/or cursor control device signals to CPU 207 . CPU 207 utilizes a lookup table containing all user profiles stored in the system to authenticate the user. Different user profiles may be given different levels of access to the system. For example, certain users may only be able to access and operate computers 115 a and 115 b and be restricted from operating servers 113 a and 113 b , serial devices 111 a and 111 b , and power supply 117 .
Once a user has been authenticated, option menu circuit 229 produces an option menu containing all the devices attached to RMU 109 . In this case, the attached devices include serial devices 111 a and 111 b , servers 113 a and 113 b , computers 115 a and 115 b , and power supply 117 . However, it would be apparent to one skilled in the art that RMU 109 may accommodate any number of serial devices, servers, computers, and associated power supplies. The option menu produced by option menu circuit 229 is compressed by video processor 212 and packetized by Ethernet connector 205 and then transmitted to user workstation 101 through RJ-45 connector 201 , communication line 121 , Internet/LAN/WAN 108 , and communication line 119 , in that order. The option menu is depacketized and decompressed at user workstation 101 for display on video monitor 105 . The user then utilizes keyboard 103 and cursor control device 107 to select the desired device from the option menu. The user-entered keyboard and cursor control device signals are then encoded by user workstation 101 , transmitted to RMU 109 via Internet/LAN/WAN 108 , and subsequently decoded by CPU 207 located in RMU 109 . CPU 207 interprets the received keyboard and cursor control device signals and interfaces the user with the selected device as previously described.
If the user selects to be interfaced with servers 113 a or 113 b or computers 115 a and 115 b , the video signal of the selected device is displayed on video monitor 105 . The video signal initially arrives from the selected device at KVM port 219 and is routed to KVM port header 217 . The video signal is then routed to frame grabber 215 which converts the analog video signal to a digital signal. The resulting digitized video signal is then routed to CPU 207 through PCI riser card 209 . CPU 207 then determines the correct location to transmit the video signal (i.e., to local KVM port 227 or video processor 212 ). If the video signal is routed to local KVM port 227 , the video signal is displayed on local video monitor 127 . Alternatively, if the video signal is routed to video processor 212 , it is compressed by video processor 212 and packetized by either Ethernet connector 205 or communications port connector 206 for transmission via communication line 121 through either RJ-45 port 201 or RJ-11 port 202 . Ethernet connector 205 or communications port connector 206 also appends any other signals (i.e., keyboard signals, cursor control device signals, etc.) onto the compressed video signal for transmission to user workstation 101 .
To switch to another connected device, the user presses a “hotkey” such as “printscreen” or “F1” on keyboard 103 attached to user workstation 101 ( FIG. 1 ). This causes option menu 229 to open an option menu allowing the user to select a new serial device, server, computer, or modify the power supply to one of the connected devices.
Referring now to FIG. 4 , depicted is a flowchart illustrating the operation of the compression algorithm utilized by video processor 212 in the preferred embodiment of the present invention. The compression algorithm is executed internal to RMU 109 by video processor 212 ( FIG. 3 ). The digitized video signal is initially stored in a raw frame buffer (step 402 ), which is one of the frame buffers 380 ( FIG. 3D ). At this point, the compression algorithm is performed to process the captured video data contained in the raw frame buffer and prepare it for transmission to user workstation 101 .
The first step of the compression algorithm is the NRDT (step 403 ). The NRDT sub-algorithm is also executed internal to RMU 109 by video processor 212 ( FIG. 3 ). The NRDT sub-algorithm determines which blocks of pixels, if any, have changed between the current frame and the compare frame, also discussed above.
In the preferred embodiment, the video frame is first divided into 64×32 pixel blocks. Subsequently, the NRDT sub-algorithm is applied to each block of pixels independently. Alternative embodiments of the present invention may utilize smaller or larger blocks depending on criteria such as desired video resolution, available bandwidth, etc.
Next, the NRDT sub-algorithm employs a two-threshold model to determine whether differences exist between a block of pixels in the current frame and the corresponding block of pixels in the compare frame. These two thresholds are the pixel threshold and the block threshold.
First, each pixel of the pixel block is examined to determine if that pixel has changed relative to the corresponding pixel of the corresponding block in the compare frame. The distance value of each of the three colors (i.e., red, green, and blue) of each pixel in relation to the corresponding compare pixel is calculated, as described in greater detail below with respect to FIG. 7 . If the distance value is larger than the pixel threshold (i.e., the first threshold of the two-threshold model), this distance value is added to a distance sum value.
Then, after all pixels within the pixel block have been examined, if the resulting distance sum value is greater than the block threshold (i.e., the second threshold of the two-threshold model), the block is determined to have changed. Every block of pixels in the video frame undergoes the same process. Therefore, after this process has been applied to an entire video frame, the process will have identified all pixel blocks that the process has determined have changed since the previous video frame. At this point, the compare frame is updated with the changed pixel blocks. However, the pixel blocks of the compare frame that correspond to unchanged pixel blocks of the current frame will remain unchanged. In this manner, the two-threshold model used by the NRDT sub-algorithm eliminates pixel value changes that are introduced by noise created during the analog to digital conversion and also captures the real changes in the video frame.
After the video data is processed by the NRDT sub-algorithm, it is next processed by the smoothing sub-algorithm (step 419 ). The smoothing sub-algorithm is designed to create a smooth, higher-quality video image by reducing the roughness of the video image caused by noise introduced during the analog to digital conversion.
The smoothing sub-algorithm first converts the pixel representation that resulted from the NRDT sub-algorithm into a pixel representation that uses a lesser quantity of bits to represent each pixel. This is performed using a CCT that is specially organized to minimize the size of the pixel representation. The smoothing sub-algorithm uses the CCT to choose color codes with the least number of 1-bits for the most commonly used colors. For example, white and black are assumed to be very common colors. Thus, white is always assigned 0 and black is always assigned 1. That is, white will be represented by a bit value of 0 on all planes. Black, the next most common color, will show up as a bit value of 1 on all but one plane. This reduces the quantity of data to be compressed by the compression algorithm. Then, for each pixel in the block, a color code is assigned. Simultaneously, a histogram of color codes is created to store the number of occurrences of each of the unique colors in the block of pixels. This histogram of color codes is then sorted to produce a list of color codes from the least number of occurrences to the dominant number of occurrences.
Once the sorted list of color codes is created, the next step is to merge colors. Working from the beginning of the sorted list, the smoothing sub-algorithm compares the least frequently occurring colors to the more frequently occurring colors. If the less frequently occurring color is very similar to a more frequently occurring color, then the pixels having the less frequently occurring color will be changed to the more frequently occurring color. Determination of whether two colors are similar is performed by calculating the distance between the three-dimensional points of the RGB space. The formula is:
D =√{square root over (( R 1 −R 2 ) 2 +( G 1 −G 2 ) 2 +( B 1 −B 2 ) 2 )}{square root over (( R 1 −R 2 ) 2 +( G 1 −G 2 ) 2 +( B 1 −B 2 ) 2 )}{square root over (( R 1 −R 2 ) 2 +( G 1 −G 2 ) 2 +( B 1 −B 2 ) 2 )}
where D is the distance, R 1 is the red value of the low frequency pixel, R 2 is the red value of the high frequency pixel, G 1 is the green value of the low frequency pixel, G 2 is the green value of the high frequency pixel, B 1 is the blue value of the low frequency pixel, and B 2 is the blue value of the high frequency pixel. If the distance is within a distance threshold, the two colors are determined to be similar. In the preferred embodiment of the present invention, system performance is increased by squaring the distance threshold and comparing this value with the sum of the squares of the RGB differences. This step eliminates taking the square root of the sum, which requires a greater amount of processing time.
Each block of pixels is filtered for noise and translated from a RGB representation to a color code representation. The noise that is introduced by LCD controller 215 ( FIG. 3 ) during conversion of the analog signals to digital signals distorts the values of some pixels. Thus, the smoothing sub-algorithm corrects distorted pixels. The smoothing sub-algorithm minimizes noise by reducing the number of different colors present in each video image block. Further, such smoothing creates an image with greater redundancy, thus yielding higher compression ratios.
After smoothing, caching is performed (step 421 ). Caching is a sub-algorithm of the overall compression algorithm executed by video processor 212 of RMU 109 ( FIG. 3 ). Caching requires RMU 109 ( FIG. 3 ) to retain a cache of recently transmitted images. Such a cache can be implemented and stored in RAM 386 ( FIG. 3D ). The caching sub-algorithm compares the most recent block of pixels with the corresponding block of pixels in the video images stored in the cache (step 405 ). If the most recently transmitted block of pixels is the same as one of the corresponding blocks of pixels stored in the cache, the caching sub-algorithm does not retransmit this portion of the video image. Instead, a “cache hit” message is sent to user workstation 101 , which indicates that the most recently transmitted block is already stored in the cache (step 407 ). The “cache hit” message contains information regarding which cache contains the corresponding block of pixels, thereby allowing user workstation 101 to retrieve the block of pixels from its cache and use it do create the video image to be displayed on its attached video display device.
The next step in the process, step 409 , determines if the NRDT determined that the block of pixels has changed since the corresponding block of pixels in the compare frame. This step can also be implemented before or in parallel with step 405 . Also, steps 421 , 405 , and 407 may be eliminated entirely.
The main purpose of step 409 is to determine whether the block has changed since the last frame. If the block has not changed, there is no need to send an updated block to user workstation 101 . Otherwise, if the block of pixels has changed, it is prepared for compression (step 411 ). In the preferred embodiment, step 409 uses a different technique than step 405 . With two ways of checking for redundancy, higher compression will result. Both steps 409 and 411 are executed by a caching sub-algorithm executed by microprocessor 388 of video processor 212 ( FIG. 3D ).
For any areas of the image that have changed, the cache is updated, and the data is compressed before being sent to the server stack. In the preferred embodiment, the image is compressed using the IBM JBIG compression algorithm. JBIG is designed to compress black and white images. However, the present invention is designed to transmit color video images. Therefore, bit planes of the image are extracted (step 411 ), and each bit plane is compressed separately (step 413 ). Finally, the compressed image is transmitted to server stack 417 (step 415 ), which transmits the data to switch 390 ( FIG. 3D ).
FIG. 5A and FIG. 5B provide detailed flowcharts of a preferred embodiment of the compression process. The digital representation of the captured video image is transferred and stored in either frame buffer 0 503 or frame buffer 1 505 . A frame buffer is an area of memory that is capable of storing one frame of video. The use of two frame buffers allows faster capture of image data. The captured frames of video are stored in frame buffer 0 503 and frame buffer 1 505 in an alternating manner. This allows the next frame of video to be captured while compression is being performed on the previous frame of video. In video processor 212 , frame buffer 0 503 and frame buffer 1 505 comprise a portion of frame buffers 380 ( FIG. 3D ).
An NRDT test is performed on each block of pixels stored in frame buffer 0 503 and frame buffer 1 505 (step 519 ), which compares each block of the captured video image to the corresponding block of the previously captured video image. Step 519 compares blocks of pixels from the video image stored in the current raw frame buffer (i.e., frame buffer 0 503 or frame buffer 1 505 ) with the corresponding block of pixels stored in compare frame buffer 521 . This step is discussed in greater detail below with respect to FIGS. 6A and 6B .
If step 519 determines that the current block of pixels has changed, then nearest color match function processes the video images contained in frame buffer 0 503 and frame buffer 1 505 (step 509 ) in conjunction with the information contained in the client color code table (“CCT from client”) 511 , which is stored in flash memory 239 ( FIG. 3 ). The nearest color match function can be executed as software by microprocessor 388 . A detailed explanation of the nearest color match function is provided below with respect to FIG. 6 .
The CCT obtained from CCT 513 by the nearest color match function is used for color code translation (step 515 ), which translates the digital RGB representation of each pixel of the changed block of pixels to reduce the amount of digital data required to represent the video data. Color code translation (step 515 ) receives blocks of pixels that the NRDT sub-algorithm (step 519 ) has determined have changed relative to the previous captured video image. Color code translation then translates this digital data into a more compact form and stores the result in coded frame buffer 517 . Coded frame buffer 517 can be implemented as a portion of RAM 386 ( FIG. 3D ).
Alternatively, steps 509 and 515 may be performed in parallel with step 519 . Performing these steps in parallel reduces the processing time required for each block of pixels that has changed. In this scenario, steps 509 and 515 are performed in anticipation of the block of pixels having changed. If this is the case, the processing for steps 509 and 515 may be completed at the same time as the processing for step 519 is completed. Therefore, the algorithm may move directly to step 523 from step 509 without having to wait for the processing of steps 509 and 515 . Otherwise, if step 519 determines that the block of pixels has not changed, and therefore the results of steps 509 and 515 are not required, these results may simply be discarded.
Upon completion of step 515 , caching begins by performing a cyclical redundancy check (CRC)(step 523 ). Cyclic redundancy check (CRC) is a method known in the art for producing a checksum or hash code of a particular block of data. The CRCs may be computed for two blocks of data and then compared. If the CRCs match, the blocks are the same. Thus, CRCs are commonly used to check for errors. In the present invention, the CRC is used to compare a block of pixels with blocks of pixels stored in a cache. Thus, in step 523 , the CRC is computed for each block of pixels that was determined to have changed by the NRDT sub-algorithm. The array of CRCs is stored in CRC array 525 .
Turning next to FIG. 5B , depicted is an overview of the caching and bit splicing/compression sub-algorithms. This portion of the algorithm begins waiting for information from coded frame buffer 517 and CRC array 525 (step 527 ). Next, a decision is made as to whether a new video mode has been declared (step 529 ). A new video mode can be declared if, for example, user workstation 101 has different bandwidth or color requirements. If a new video mode has been declared, all data is invalidated (step 531 ) and the sub-algorithm returns to step 527 to wait for new information from coded frame buffer 517 and CRC array 525 . Downscaler circuit 362 and/or upscaler circuit 364 , located in LCD controller 215 , may be utilized to adjust the outputted digitized video to be compatible with the new video mode. Steps 527 , 529 , and 531 are all steps of the overall compression algorithm that is executed by microprocessor 388 ( FIG. 3D ).
If in step 529 it is deemed that a new video mode has not been declared, then the comparison of the current block of pixel's CRC with the cached CRCs is performed (step 533 ). This block compares the CRC data of the current video frame contained in CRC array 525 with the cache of previous CRCs contained in block info array 535 . Block info array 535 stores the cache of pixel blocks and the CRCs of the pixel blocks and can be implemented as a device in RAM 386 ( FIG. 3D ). Step 533 is also a part of the overall compression algorithm executed by microprocessor 388 ( FIG. 3D ).
Next, if the current block of pixels is located within the pixel block cache contained in block info array 535 (step 537 ), a cache hit message is sent to user workstation 101 and the block of pixels is marked as complete, or processed (step 539 ). Since user workstation 101 contains the same pixel block cache as RMU 109 ( FIG. 3D ), the cache hit message simply directs user workstation 101 to use a specific block of pixels contained in its cache to create the portion of the video image that corresponds to the processed block of pixels.
Next, a check is performed for unprocessed blocks of pixels (step 539 ). All blocks of pixels that need to be processed, or updated, are combined to create a compute next update rectangle. If there is nothing to update (i.e., if the video has not changed between frames), then the algorithm returns to step 527 (step 543 ). Thus, the current frame will not be sent to the remote participation equipment. By eliminating the retransmission of a current frame of video, the sub-algorithm reduces the bandwidth required for transmitting the video.
If, however, there are areas of the image that need to be updated, the update rectangle is first compressed. The update rectangle must first be bit sliced (step 545 ). A bit plane of the update rectangle is constructed by taking the same bit from each pixel of the update rectangle. Thus, if the update rectangle includes 8-bit pixels, it can be deconstructed into 8 bit planes. The resulting bit planes are stored in bit plane buffer 547 . Again, steps 541 , 543 , and 545 are all part of the bit splicing/compression sub-algorithm executed by microprocessor 388 of RMU 109 ( FIG. 3 ).
Each bit plane is compressed separately by the compression sub-algorithm (step 549 ). In this case, compression is performed on each bit plane and the resulting data is sent to server stack 417 (step 551 ). In the preferred embodiment, compression is performed by video compression device 382 ( FIG. 3 ) (step 549 ). Thereafter, the compressed bit planes are sent to switch 390 ( FIG. 3D ).
Since the preferred embodiment captures frames 20 times per second, it is necessary to wait 300 ms between video frame captures. Thus, the algorithm waits until 300 ms have passed since the previous frame capture before returning the sub-algorithm to step 527 (step 553 ).
Referring now to FIG. 6 , illustrated is the nearest color match function (step 509 of FIG. 5A ) that selectively maps less frequently occurring colors to more frequently occurring colors using a CCT. Nearest color match function 509 processes each block of pixels of the video image stored in frame buffer 0 503 or frame buffer 1 505 successively. As shown in FIG. 6 , a block of pixels is extracted from the video image stored in frame buffer 0 503 or frame buffer 1 505 (step 600 ). In the preferred embodiment, the extracted block has a size of 64 by 32 pixels, however, any block size may be utilized.
The nearest color match function eliminates noise introduced by the A/D conversion by converting less frequently occurring pixel values to similar, more frequently occurring pixel values. The function utilizes histogram analysis and difference calculations. First, nearest color match function 509 generates a histogram of pixel values (step 601 ). The histogram measures the frequency of each pixel value in the block of pixels extracted during step 600 . The histogram is sorted, such that a list of frequently occurring colors (popular color list 603 ) and a list of least frequently occurring colors (rare color list 605 ) are generated. The threshold for each list is adjustable.
Then, nearest color match function 509 analyzes each low frequently occurring pixel to determine if the pixel should be mapped to a value that occurs often. First, a pixel value is chosen from rare color list 605 (step 607 ). Then, a pixel value is chosen from popular color list 603 (step 609 ). These distance between these two values is then computed (step 611 ). In this process, distance is a metric computed by comparing the separate red, green and blue values of the two pixels. The distance value D may be computed in a variety of ways. One such example is:
D =( R 1 −R 2 ) 2 +( G 1 −G 2 ) 2 +( B 1 −B 2 ) 2
In this formula, R1 is the red value of the low frequency pixel, R2 is the red value of the high frequency pixel, G1 is the green value of the low frequency pixel, G2 is the green value of the high frequency pixel, B1 is the blue value of the low frequency pixel, and B2 is the blue value of the high frequency pixel.
This formula yields a distance value, D, which indicates the magnitude of the similarity or difference of the colors of two pixels, such as a less frequently occurring pixel versus a more frequently occurring pixel. The goal of the sub-algorithm is to find a more frequently occurring pixel having a color that yields the lowest distance value when compared to the color of a less frequently occurring pixel. Therefore, a comparison is performed for each computed distance value (step 613 ). Every time a distance value is computed that is less than all previous distance values, the distance value is written to the closest distance variable (step 615 ).
Once it is determined that all more frequently occurring pixels have been compared to less frequently occurring pixels (step 617 ), a computation is performed to determine if the lowest occurring D is within a predefined threshold (step 619 ). If this D is within the predefined threshold, CCT 513 is updated by mapping the low frequently occurring pixel to the color code value of the high frequently occurring pixel that yielded this D value (step 621 ). This process is repeated for all low frequency pixels and CCT 513 is updated accordingly.
Turning to FIG. 7 , RGB NRDT step 519 ( FIG. 5A ) is illustrated in further detail. This process operates on every block of pixels. Current pixel block 700 represents a block of pixels of the video image contained in the current frame buffer (i.e., frame buffer 0 503 or frame buffer 1 505 ( FIG. 5A )). Previous pixel block 701 contains the corresponding block of pixels of the video image contained in compare frame buffer 521 ( FIG. 5A ). Step 519 begins by extracting corresponding pixel values for one pixel from the current pixel block 700 and previous pixel block 701 (step 703 ). Then, the pixel color values are used to calculate a distance value, which indicates the magnitude of the similarity or difference between the colors of the two pixels (step 705 ). In the preferred embodiment of the present invention, the distance value is computed using the following formula:
D =( R 1 −R 2 ) 2 +( G 1 −G 2 ) 2 +( B 1 −B 2 ) 2
As before, R1, G1, and B1 are the red, green and blue values respectively of the frame buffer pixel. Similarly, R2, G2, and B2 are the red, green and blue values respectively for the compare frame buffer pixel.
Next, the computed distance value D is compared with a pixel threshold (step 707 ). If D is greater than the pixel threshold, it is added to an accumulating distance sum (step 709 ). If the value of D is less than the pixel threshold, the difference is considered to be insignificant (i.e., noise) and it is not added to the distance sum.
This process of computing distance values and summing distance values that are greater than a predefined pixel threshold continues until it is determined that the last pixel of the block of pixels has been processed (step 711 ). Once the last pixel is reached, the distance sum is compared with a second threshold, the block threshold (step 713 ). If the distance sum is greater than the block threshold, the current block of pixels designated as changed as compared to the corresponding block of pixels from the previously captured frame. Otherwise, if the distance sum is less than the block threshold, the block of pixels is designated as unchanged.
If the block of pixels is designated as changed, step 715 is executed. Step 715 sets a flag that indicates that the particular block of pixels has changed. Furthermore, the new block of pixels is written to compare frame buffer 521 ( FIG. 5A ) to replace the corresponding previous block of pixels.
Otherwise, if the distance sum does not exceed the block threshold, the block is designated unchanged and, a flag is set to indicate that this block of pixels does not need to be re-transmitted to the remote participation equipment (step 721 ). Rather, the remote participation equipment will recreate the portion of the video image represented by the block of pixels using the same block of pixels displayed for the previous frame of video. At this point the system computers CRCs for changed blocks of pixels (step 523 of FIG. 5A ) as discussed in greater detail above with respect to FIG. 5A .
FIG. 8 further illustrates the two level thresholding used by the NRDT sub-algorithm shown in FIG. 7 . For illustrative purposes only, 4×4 blocks of pixels are shown. Each pixel is given red, green, and blue color values that range from 0 to 255, as is commonly performed in the art. A pixel having red, green, and blue values of 0 represents a black pixel, whereas a pixel having red, green, and blue values of 255 represents a white pixel. Previous pixel block 751 is a block of pixels grabbed from compare frame buffer 521 ( FIG. 5A ). Previous pixel 1 752 is the pixel in the upper, left corner of previous pixel block 751 . Since every pixel of previous pixel block 751 has a value of 0, previous pixel block 751 represents a 4×4 pixel area that is completely black.
Current pixel block 753 represents the same spatial area of the video frame as previous pixel block 751 , but it is one frame later. Here current pixel 1 754 is the same pixel 1 as previous pixel 1 752 , but is one frame later. For simplicity, suppose a small white object, such as a white cursor, enters the area of the video image represented by previous pixel block 751 . This change occurs in current pixel 1 754 of current pixel block 753 . In current pixel block 753 , the majority of the pixels remained black, but current pixel 1 754 is now white, as represented by the RGB color values of 255, 255, and 255.
Further suppose that noise has been introduced by the A/D conversion, such that previous pixel 755 has changed from black, as represented by its RGB values of 0, 0, and 0, to gray. The new gray color is represented by the RGB values of 2, 2, and 2 assigned to current pixel 756 .
Further suppose that the pixel threshold is 100, and the block threshold is 200. The NRDT sub-algorithm calculates the distance value between each pixel of current pixel block 753 and previous pixel block 751 . The formula used in the preferred embodiment of the present invention, as discussed above with respect to FIG. 7 , is:
D =( R 1 −R 2 ) 2 +( G 1 −G 2 ) 2 +( B 1 −B 2 ) 2
Therefore, the distance value between current pixel 1 754 and previous pixel 1 752 is:
D =(255−0) 2 +(255−0) 2 +(255−0) 2
or 195,075. This distance value is added to the distance sum because 195,075 exceeds the pixel threshold of 100. However, the distance value between the black previous pixel 755 and the gray current pixel 756 is not added to the distance sum because the distance between the pixels, as calculated using the above distance formula, equals 12, which does not exceed the pixel threshold of 100. Similarly, the distance value is computed for all of the remaining pixels in the two pixel blocks. Each of these distance values equals zero, therefore, since these distance values are less than the pixel threshold, they are not added to the distance sum.
Consequently, after the distance values for all pixels have been processed, the distance sum equals 195,075. Since this value is greater than the block threshold of 200, the block is designated. This example illustrates the advantages of the two-level thresholding feature of the NRDT sub-algorithm. That is, the noise that occurred in current pixel 756 of current pixel block 753 was ignored, whereas the real change in video that occurred in current pixel 1 754 of current pixel block 753 was recognized.
Turning finally to FIG. 9 , shown is a flowchart of the decompression algorithm executed by user workstation 101 ( FIG. 1 ). The decompression algorithm begins by waiting for a message (step 801 ). This message is transmitted from server stack 417 of RMU 109 to user workstation 101 . Thereafter, user workstation 101 receives the information and writes the data to client stack 803 . Client stack 803 may be a register or some other device capable of permanently or temporarily storing digital data. In one embodiment of the present invention, messages are transmitted using the TCP/IP communication protocol. In this scenario, client stack 803 is the local TCP/IP stack. Other embodiments may use a protocol other than TCP/IP. However, irrespective of the communication protocol, the present invention uses client stack 803 to store received messages for processing.
Once a message is received in client stack 803 , it is processed to determine whether the message is a new video mode message (step 805 ). A new video mode message may be sent for a variety of reasons including a bandwidth change, a change in screen resolution or color depth, a new client, etc. This list is not intended to limit the reasons for sending a new video mode message, but instead to give examples of when it may occur. If the message is a new video mode message, application layer 823 is notified of the new video mode (step 807 ). According to the preferred embodiment, application layer 823 is software executed by user workstation 101 that interfaces with the input and output devices of user workstation 101 (i.e., keyboard 103 , video monitor 105 , and cursor control device 107 ). Any video updates must therefore be sent to application layer 823 . Also, the old buffers are freed, including all memory devoted to storing previously transmitted frames, and new buffers are allocated (step 809 ). The decompression algorithm then returns to step 801 .
If the new message is not a video mode message, the message is further processed to determine if it is a cache hit message (step 811 ). If yes, the cache hit message is deciphered to determine which block of pixels, of the blocks of pixels stored in the three cache frame buffers 815 , should be used to reconstruct the respective portion of the video image. Although three cache frame buffers 815 are used in the preferred embodiment of the present invention, any quantity of cache frame buffers may be used without departing from the spirit of the invention. Cache frame buffers 815 store the same blocks of pixels that are stored in the cache frame buffers located internal to RMU 109 ( FIG. 3 ). Thus, the cache hit message does not include video data, but rather simply directs the remote participation equipment as to which block of pixels contained in the cache frame buffer 815 should be sent to merge frame buffer 817 . The block of pixels contained within the specified cache is then copied from cache frame buffer 815 to merge buffer 817 (step 813 ). Finally, application layer 823 is notified that an area of the video image has been updated (step 825 ). Merge buffer 817 contains the current representation of the entire frame of video in color code pixels. Application layer 823 copies the pixel data from merge buffer 817 and formats the data to match the pixel format of the connected video monitor 105 (step 819 ). Thereafter, the formatted pixel data is written to update frame buffer 821 , which then transmits the data to video monitor 105 . Alternatively, in lieu of a video monitor, the formatted pixel data may be written to a video card, memory, and/or any other hardware or software commonly used with video display devices.
Further, if the new message is not a new video mode or cache hit message, it is tested to determine if it is a message containing compressed video data (step 827 ). If the message does not contain compressed video data, the decompression algorithm returns to step 801 and waits for a new message to be transmitted from server stack 417 . Otherwise, if the message does contain compressed video data, the data is decompressed and transferred to bit plane frame buffer 833 (step 829 ). As described above, the preferred embodiment incorporates the JBIG lossless compression technique. Therefore, decompression of the video data must be performed for each individual bit plane. After each bit plane is decompressed, it is merged with previously decompressed bit planes, which are stored in bit plane frame buffer 833 (step 829 ). When a sufficient number of bit planes have been merged, the merged data contained in bit plane frame buffer 833 is transferred to merge frame buffer 817 (step 831 ). Alternatively, individual bit planes may be decompressed and stored directly in merge frame buffer 817 , thereby eliminating step 831 . When all of the data required to display a full frame of video is transferred to merge frame buffer 817 , application layer 823 copies the data in merge frame buffer 817 to update frame buffer 821 (step 819 ). Thereafter, the data is transferred to video monitor 105 .
In an alternate embodiment, the video displayed on video monitor 105 can be updated after each bit plane is received. In other words, a user does not have to wait until the whole updated frame of video is received to update portions of the displayed video. This alternative method is desirable when the bandwidth available for video transmission varies. Also, this progressive method of updating the video display is one of the advantages of using the JBIG compression algorithm.
Next, the decompression algorithm determines whether all of the color code data from one field of the current video frame has been received (step 835 ). If a full field has not been received, the decompression algorithm returns to step 801 and waits for the remainder of the message, which is transmitted from server stack 417 to client stack 803 in the form of a new message. Otherwise, if a full field has been received, the decompression method notifies application layer 823 (step 837 ). Similar to that described above with respect to processing cache hit messages, this notification directs application layer 823 to read the data in merge frame buffer 817 and convert it to the current screen pixel format (step 819 ). Thereafter, the formatted data is written to update frame buffer 821 , which transmits the data to video monitor 105 .
After a full field has been received and application layer 823 has been notified, a second determination is made to determine if the full field is the last field included in the message. If it is, the newly decompressed block of pixels is written to one of the cache frame buffers 815 (step 841 ). Otherwise, the decompression algorithm returns to step 801 and continues to wait for a new message. Preferably, the new block of pixels written to cache frame buffer 815 overwrites the oldest block of pixels contained therein. Step 841 ensures that the cache is up-to-date and synchronized with the cache of RMU 109 . After the completion of the cache update, the decompression algorithm returns to step 801 .
While the present invention has been described with reference to the preferred embodiments and several alternative embodiments, which embodiments have been set forth in considerable detail for the purposes of making a complete disclosure of the invention, such embodiments are merely exemplary and are not intended to be limiting or represent an exhaustive enumeration of all aspects of the invention. The scope of the invention, therefore, shall be defined solely by the following claims. Further, it will be apparent to those of skill in the art that numerous changes may be made in such details without departing from the spirit and the principles of the invention. It should be appreciated that the present invention is capable of being embodied in other forms without departing from its essential characteristics.
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Disclosed is a remote network management system for coupling a series of remote domain servers, file/print servers, headless servers, network appliances, serial IT equipment, switches, routers, firewalls, security interfaces, application servers, load balancers, and environmental controls to one or more user workstations allowing for selective access of the remote devices. The remote devices are all connected to a remote management unit which interfaces each user workstation to the remote devices. The power supply of each remote device is similarly connected to the remote management unit through a controllable power supply. An option menu containing a list of all of the remote devices allows a user to select and operate any of the remote devices from the workstation. The option menu is also utilized to selectively control the power to the remote devices, servers, and computers.
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BACKGROUND OF THE INVENTION
This invention relates to improved devices for locking cords against longitudinal movement relative to the device.
My prior U.S. Pat. No. 3,845,575 shows a device for retaining a cord or string against longitudinal movement relative to the device, and in which the ends of the cord or cords are held in a looped contion giving a bow-like appearance. Such devices are useful for example in holding and controlling the ends of a shoe string, or other similar cord or string. In the arrangement of my mentioned patent, the extremities of the shoe string are retained by extension through an opening in a shiftable slide of the locking device, which slide is movable relative to a body of the device and within an inner passage therein to lock and release the cord. Other proposals for retaining the ends of a cord or cords are shown in U.S. Pat. Nos. 3,138,839 and 2,318,411.
SUMMARY OF THE INVENTION
The major purpose of the present invention is to provide an improved cord locking device of the above discussed general type, in which the cord ends are retained in looped or bowed condition, and in which the overall cord and locking combination can be assembled with maximum ease and simplicity, and will present an optimum appearance when in use. Desirably, the assembled lock and cord have a very small overall thickness, in order to avoid excessive protrusion of the device from the surface of the shoe or the like.
Structurally, a device embodying the invention includes a body containing a central passage through which two cords extend (which "two cords" may in fact be opposite ends of a single cord) and a locking element or slide mounted movably within the central passage to releasably lock the cords against longitudinal movement, with the body containing two additional passages which are located at opposite sides of the main central passage and are adapted to receive and hold the cords near their extremities in a manner retaining the cords in the desired looped configuration. The two side passages at opposite side of the main central passage preferably extend in essentially the same direction as the central passage itself, and may be open at both ends so that the tips of the two cords can be threaded into the passages in either of two opposite directions to attain two different bow appearances. A pair of spaced walls of the body may serve dual purposes, as the outer walls of the central cord passage of the device, and inner walls of the two opposite side passages respectively. In this event, the two mentioned walls may have inner converging surfaces facing inwardly toward and defining opposite sides of the central passage, and have outer non-converging surfaces forming the inner sides of the two side passages. Additional walls extending between the front and rear sides of the body at locations spaced laterally outwardly beyond the two first mentioned walls may define the outer sides of the two side passages.
BRIEF DESCRIPTION OF THE DRAWING
The above and other features and objects of the invention will be better understood from the following detailed description of the typical embodiments illustrated in the accompanying drawings in which:
FIG. 1 is a fragmentary front view of a cord locking assembly constructed in accordance with the invention, and shown as utilized for retaining a shoe string against loosening movement;
FIG. 2, is an enlarged side view taken on line 2--2 of FIG. 1;
FIG. 3 is a section taken on line 3--3 of FIG. 2;
FIG. 4 is a rear view of the device taken on line 4--4 of FIG. 2;
FIG. 5 is a transverse section taken on line 5--5 of FIG. 3;
FIG. 6 shows the device of FIGS. 1 to 5 with the ends of the cord or shoestring inserted in their retaining openings in reverse direction;
FIGS. 7 and 8 are views similar to FIG. 2, but showing the device with two variational types of locking slides; and
FIG. 9 is a sectional view taken on line 9--9 of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference first to FIG. 1, I have represented fragmentarily at 10 shoe which is closed by a conventional shoe string 11 threaded through two parallel rows of eyelets 12. The opposite ends of string 11 are releasably retained in tightened condition by a cord locking device 13 which is constructed in accordance with the invention and holds the string in a manner forming two similar loops 14 and 15 giving the appearance of a bow knot. It will of course be understood that the two cord ends which are secured together by the device 13 may in some instances be portions of two entirely separate cords, rather than opposite ends of a single string or cord as shown. In the claims appended to this specification, the two cord ends are for simplicity referred to as two cords.
The locking device 13 includes a body 16 and a relatively movable locking slide 17, both of which may be molded from an appropriate resinous plastic material or materials selected and dimensioned to give body 16 the characteristics of an essentially rigid element in use, and to give slide 17 a capacity for resilient defomability as will be discussed hereinafter.
Body 16 has a front wall 21 which is essentially flat or planar and disposed transversely of an axis 19, with the peripheral edge 22 of wall 21 being circular about axis 19 as seen in FIG. 1. A rear wall 18 of body 16 is planar and disposed transversely of axis 19 and is parallel to front wall 21 and of the same circular outline configuration except insofar as the peripheral edge 20 of wall 21 may be interrupted by two circularly spaced notches or cutaways 123 and 124 at the locations illustrated in FIG. 4.
Between the planar rear surface 24 of wall 21 and the parallel planar front surface 23 of wall 18, body 16 forms a main central passage 25 through which the two cord portions 26 and 27 extend. The passage 25 may be considered as extending essentially along an axis 28, which is also the direction of sliding movement of locking unit 17. Passage 25 is defined by surfaces 23 and 24, and by two laterally spaced walls 29 and 30 extending between those surfaces 23 and 24 and interconnecting front wall 21 and rear wall 18. At their inner sides, walls 29 and 30 have opposed planar surfaces 31 and 32 which converge as they advance upwardly as viewed in FIG. 3, to form opposite sides of the tapering passage or throat 25 within slide 17 and the cords are received.
At opposite sides of main passage 25, body 16 forms two smaller side passages 33 and 34 within which end portions of the cord or cords are received. As seen in FIG. 5, these passages may be of approximately circular cross section, typically slightly enlarged in the direction represented by the arrow 35 of FIG. 5, with the cross sectional size of these passages 33 and 34 preferably being just slightly smaller in at least one transverse direction than the normal diameter of the shoe string, so that when the shoe string is threaded through each of these passages it is closely confined therein and slightly deformed from its normal cross sectional configuration in a manner effectively retaining the engaged portion of the string frictionally against longitudinal movement and therefore in essentially fixed position relative to the body unless forceably moved relative thereto. The passages 33 and 34 are defined at their inner sides by approximately cylindrically curved surfaces 36 and 37 formed on the outer sides of walls 29 and 30, which thus function as partitions between the various passages. The outer sides of passages 33 and 34 are defined by inner approximately cylindrically curved surfaces 38 and 39 formed on short walls 40 and 41 extending between and connecting front and rear walls 21 and 18 of the body at their opposite side edges. As will be apparent from FIGS. 3 and 5, the side passages 33 and 34 desirably extend in approximately the same direction as main central passage 25, and for best results have their longitudinal axes 42 and 43 disposed exactly parallel to axis 28 of the central passage. It is also noted that the length m of outer walls 40 and 41 in the direction of the axes 28, 42 and 43 is preferably substantially less than the length n of walls 29 and 30 in the same direction.
At the upper ends of walls 29 and 30 as viewed in FIG. 3, these walls have end surfaces 44 which are disposed transversely of axis 28 and merge with surfaces 31 and 32 at rounded corners 45, so that the cords can be turned laterally adjacent these surfaces 44 as shown in FIG. 3. The previously mentioned notches 123 and 124 in rear wall 18 are located just upwardly beyond the location of surfaces 44 as viewed in FIG. 3, so that after the cords have been turned laterally adjacent surfaces 44 they can be pulled rearwardly into notches 123 and 124 if desired to avoid interference with the tips 45 at the ends of the shoestring and the portions of the string adjacent those tips, and to facilitate extension of the cords rearwardly into two of the grommets 12.
The slide 17 which is illustrated in FIGS. 1 to 6 has been disclosed in great detail in my U.S. Pat. No. 3,965,544, and takes the form of an essentially U-shaped part having two arms 46 and 47 joined integrally together by a return bend portion 48 of the slide, and having teeth 49 at their outer sides positioned to press the two cords or cord portions laterally against converging side wall surfaces 31 and 32 of passage 25 to lock the cords against upward movement in FIG. 3. The resilience of parts 17 normally urges arms 46 and 47 relatively apart and toward their locking positions, and the arms can be retracted inwardly away from surfaces 31 and 32 and to positions such as those represented in broken lines at 117 in FIG. 3 by manual engagement of two handle portions 50 formed at the extremities of the arms 46 and 47. When thus squeezed together, the arms 46 and 47 can be pulled downwardly in FIG. 3 to a position in which the cords can be pulled freely in either direction within passage 25. The movement of slide 17 along axis 28 is limited by engagement of lugs 51 formed on arms 17 with the opposite ends of an elongated slot 52 in rear wall 18 into which lugs 51 project.
In applying the locking device 13 to the shoe of FIG. 1, the two ends of cord 11 after passing through the upper grommets 12 of the shoe are passed downwardly through central passage 25 of body 16, are then allowed to extend downwardly beyond passage 25 at 53 and 54, and ultimately curve back upwardly at 55 and 56 toward passages 33 and 34. The tips 45 of the cord or string are threaded upwardly through passages 33 and 34 and to the FIG. 3 positions in which the tips may be located just upwardly beyond body 16, with the portions of the cords which are received within passages 33 and 34 being frictionally retained at set locations therein. The slide 17 is apropriately located within passage 25, between the two cords or cord portions as seen in FIG. 3, and will act to lock the cords against upward movement within passage 25 while permitting free downward movement of the cords therein. The portions 53 and 54 of the cords may thus be pulled downwardly until the shoe has been properly tightened on the foot of the wearer, and slide 17 will automatically retain the cord in this tight position with the loops 14 and 15 giving to the string the appearance of a bow knot. When it is desired to loosen the string, the wearer merely squeezes the two handle portions 50 of slide 17 together and moves the slide downwardly to enable the two portions of the cord to move upwardly within passage 25 as far as may be desired.
Instead of threading the cord tips 45 upwardly within the opposite side passages 33 and 34 of the device, the tips may be threaded downwardly through those passages as seen in FIG. 6, to give the bow loops a somewhat different appearance, but with the locking characteristic remaining the same.
In the variational type of locking device illustrated at 10a in FIG. 7, the body 16a may be identical with the previously described body 16 of the first form of the invention, but with a different type of slide 17a being provided. In particular, this slide 17a is not of the U-shaped double arm type shown in FIG. 3, but rather is a solid element having two sets of teeth 49a formed at opposite sides thereof in fixed relative positions, with a lug 51a at the rear side of slide 17a projecting into a slot 52a corresponding to slot 52 of FIG. 3, to retain the slide in its assembled position within the body while allowing upward and downward relative movement of the slide to lock and release the cords. As in the first form of the invention, the body 16a of FIG. 7 contains a central main passage 25a and two side passages 33a and 34a on opposite sides of passage 25a and the contained slide. The cords or string ends are passed through and locked in main passage 25a in the same manner discussed in connection with the first form of the invention, and are then looped to form an essentially bow shaped pattern and doubled back into side passages 33a and 34a as in FIG. 3 or FIG. 6.
In FIG. 8, the body 16b is typically illustrated without the notches 123 and 124 of FIGS. 3 and 4, but may otherwise be the same as body 16 of the first form of the invention. It will of course be understood that the notches 123 and 124 may either be provided or not in any of the forms of the invention, as may be desired for a particular use. The slide 17b of FIG. 8 is located entirely within the body except for extension of an actuating or shifting button 51b through slot 52b in the rear wall of the body. This button 51 is thus accessible for manual actuation by the thumb of a user, to move the slide upwardly and downwardly in FIG. 8 for locking or releasing the cords. Two sets of teeth 49b formed on opposite sides of slide 17b engage the two cords or cord portions to press them against the walls of tapering throat 25b. It also may be noted that button 51b may be of square or rectangular cross section (see FIG. 8) and of a width corresponding to the width of elongated slot 52b, in a manner retaining the button and the rest of part 17b against turning movement about an axis such as that represented at 57 in FIG. 9.
While certain specific embodiments of the present invention have been disclosed as typical, the invention is of course not limited to these particular forms, but rather is applicable broadly to all such variations as fall within the scope of the appended claims.
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A cord locking device including a body containing a central passage through which cords extend, and within which the cords can be releasably retained against longitudinal movement by a shiftable locking slide in the passage, with the ends of the cords in locked condition forming loops having a bow-like configuration and extending outwardly away from the body and then back to the body, and with the body containing two side passages located at opposite sides respectively of the main central passage and adapted to receive and hold the second ends of the loops to maintain the looped configuration.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a door handle notably for a motor vehicle, and more particularly a door handle incorporating at least one presence sensor to detect the presence of a user at the handle.
The invention also relates to a hands-free access system for a motor vehicle including such a handle.
2. Description of the Related Art
In the early days of the automobile, the door handle served only to transmit mechanical movements via tie-rods to a door-catch to open the door. Today the door handle has undergone great changes.
In particular, in so-called “hands-free” systems enabling locking and unlocking of a motor vehicle without a mechanical key or remote control, the handle has become a special interface between the user, wearing an identifier in the form of a badge, for example, and the vehicle's onboard system.
A handle as used in a “hands-free” system is shown in FIG. 1 .
Generally, such a handle 1 comprises two parts, a grasping part 2 that is mobile relative to the door 4 of the vehicle and a fixed part 3 that is essentially decorative or houses, for example, a backup lock. Both the mobile part 2 and the fixed part 3 are made of plastic material.
As seen in FIG. 1 , the mobile part has an internal cavity 6 serving as a housing for a support module 7 . To enable the module to be fitted in the handle the internal cavity 6 (hereinafter referred to as the “housing”) is open on one side in a zone located opposite the fixed part 3 . The housing 6 is closed by a plugging part 6 bis.
The support module 7 includes presence sensors and notably an approach sensor 9 and a tactile sensor 8 .
The approach sensor 9 is used to initiate the communication between the identifier and the vehicle's onboard system when the user approaches the vehicle, whereas the tactile sensor 8 is used to detect a voluntary action by the user to lock the vehicle.
As shown in FIG. 1 , the approach detection zone 12 associated with the approach sensor 9 is situated between the door 4 and the grasping part 2 of the handle.
The approach sensor 9 is for example a capacitive sensor that operates by measuring the variation of the electromagnetic field surrounding it. It has at least one detection electrode 10 whose shape enables an extended and well-defined detection zone between the door 4 and the grasping part of the handle 2 .
The tactile sensor 8 is also a capacitive sensor, for example. It has a detection electrode 10 which enables detection over a precisely defined zone 11 located at the outer surface of the handle. This tactile detection 11 zone has high sensitivity to a touching action.
Such an arrangement of the various parts in the handle has the disadvantage of offering very limited freedom for positioning the various sensors on the support module owing to the small size of the housing 6 , imposed by mechanical constraints. The result is that the location of the various detection zones is practically imposed by the geometry of the handle and its housing.
Consequently, these various detection zones may find themselves located in relatively inaccessible places or may present major usability problems. Furthermore, such an arrangement does not enable the use of standard handles usable by both left-handed and right-handed users, since this implies being able to choose the position of the various detection zones such that they are quite distinct and easily accessible to the user.
Moreover, it has been observed, later, that when such handles are painted, metal-plated or even solid metal, the operation of the presence sensors is highly perturbed.
In effect, a conductive coating, which can be a chemical deposit such as chrome-plating, paint, a primer for decorative coatings or even the material constituting the handle, causes modification of the capacitive couplings between the detection electrodes of the various sensors and the surface of the handle.
This perturbation mainly associated with the electrical conductivity of the coating results in a change of the shape of the presence detection zones covered by the various presence sensors and consequently lowers sensitivity of the sensor.
In the case of the approach sensor, spreading of the detection zone is observed, accompanied by a substantial reduction in the detection distance from the handle. Remote detection (i.e. at a distance of a few centimeters) of an approaching user is no longer possible: the user must be within one centimeter—or even in contact with the handle—for the detection to be made. The reason is that the conductive coating constitutes a screen for the electric field lines of the approach sensor, which greatly reduces the ability to detect presence by measuring electrical capacitance.
In the case of the tactile sensor, spreading of the tactile detection zone over a large part of the handle surface is usually observed, with a consequent large drop in sensitivity of the sensor and total loss of the tactile detection function.
To illustrate this problem better, FIG. 2 shows schematically the sensitivity S of a tactile sensor 8 relative to the width of the electrode 10 , in one dimension only.
The solid curve A shows the sensitivity curve of the tactile sensor for a handle made of electrically insulating material. This curve A has a flat section P whose width E corresponds substantially to the width of the electrode 10 . It is seen that the sensitivity drops off strongly on each side.
The dashed curve B shows the sensitivity of the tactile sensor for a handle with a conductive surface coating. This sensitivity curve is broader and its maximum height is much less than curve A, which implies malfunctions of the sensor 8 ; moreover, this curve has no characteristic plateau, which signifies that the detection zone is spread and not very well defined, which is a serious handicap in terms of usability.
As stated previously, the presence of this conductive coating perturbs the tactile sensor due to the spreading of the tactile detection zone over a larger surface of the handle, resulting in serious loss of sensitivity of the sensor. The tactile detection is therefore strongly perturbed.
The lack of flexibility in the positioning of the detection zones of the approach and tactile sensors plus, in the case of painted or metal-plated handles, the modification of these zones and the resulting weak detection are particularly problematic.
SUMMARY OF THE INVENTION
The invention aims to overcome these disadvantages and propose a solution for creating a new presence detection zone that is easily accessible, ergonomic and compatible with a conductive handle or a handle with a conductive surface coating, such that approach or tactile detection is assured.
The solution proposed consists in adding conducting means between the detection electrode of the presence sensor and the location at the handle surface where this new detection zone is to be created. In the case of a perturbing conductive coating, these conducting means are preferentially more conductive than this coating.
In the case of an approach sensor, the detection distance is increased to create a new detection zone that is better controlled, by directing the electric field lines generated by the sensor inside the handle to slots at the surface of the handle.
In the case of a tactile sensor, the initial detection zone of the tactile sensor is then shifted by capacitive coupling and electrical conduction phenomena to the place where this new detection zone is to be created.
In this manner, it is possible to create a new approach or tactile presence detection zones at the outer surface of the handle arid to ensure normal operation of the whole “hands-free” system even when the surface of the handle is conductive. These new presence detection zones can be located close to the conductive coating but must be isolated from it by insulating means.
To this end, the object of the invention is a door handle, in particular for a motor vehicle, comprising at least one presence sensor having at least one electrode for detecting the presence of a user at said handle, wherein it comprises conducting means having at least one proximal end directly or indirectly connected by capacitive coupling to said detection electrode and at least one distal end emerging in electrical insulation on the outer surface of the handle so as to create at least one new zone for detecting the presence of a user.
The door handle according to the invention can also include one or more of the following characteristics:
the door handle has a grasping part with an inner housing, formed by an elongated cavity in this grasping part, that houses said presence sensor, said presence sensor has at least two electrodes and, for each electrode, said conducting means have an associated proximal end that positions near this electrode, said proximal end of said conducting means is formed by a metal blade positioned near said electrode and of which at least one part is approximately parallel to it, said conducting means are formed by a single metal blade, said presence sensor is carried by a support module that is inserted in said housing, said metal blade takes the form of a spring positioning and/or holding said support module in said housing, said metal blade is fixed on said support module or on said presence sensor, said handle also has at least one opening emerging on the outer surface of the handle and said distal end of said conducting means is flush with this outer surface, said conducting means have a number of distal ends flush with the outer surface of the handle at the positions of the associated openings, said openings are aligned parallel to a longitudinal axis of the grasping part of the handle, said conducting means are held in said opening by fastening means also serving as electrical insulator, said fastening means are formed by a glue or clipping means in plastic material, said conducting means are overmoulded with an insulating material, said insulating material forms the plugging means for said openings, said conducting means have an intermediate part constituted by plugging means ( 18 ) of said housing ( 6 ) of said presence sensor, said metal blade is fixed to and/or formed from the material of said plugging means, said distal end of the conducting means include a movable part, said movable part is a lock cache, notably of a backup lock, said distal end forms a conductive part of a handle part ( 3 ) fixed relative to the door, and said presence sensor is housed in a mobile grasping part of the handle, the handle is made from a plastic material, the outer surface of the handle is covered with a conductive coating, said conducting means having a number of distal ends flush with the outer surface of the handle at the positions of the associated openings, said conductive coating is a metalized paint or a direct metalization, the handle is made from metal and also includes electrical insulation means forming a sheath for said conducting means, said presence sensor is an approach sensor to detect the approach of a user near the handle, said presence sensor is a tactile sensor to detect a user touching the handle, the new detection zone of said tactile sensor is delimited by the shape of said distal end of said conducting means, said presence sensor is a sensor of capacitive type.
Another object of the invention is a hands-free access system for a motor vehicle including such a door handle.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood on reading the detailed description below of embodiments, which are non-limitative and taken only as examples, with reference to the attached drawings of which:
FIG. 1 is a sectional view of a handle of the prior art showing the location at the surface of the handle of the detection zones of the various presence sensors;
FIG. 2 is a schematic presentation of the detection profile of a handle tactile sensor in different conditions of use;
FIG. 3 is a partial sectional view of the handle in which the proximal end of the conducting means takes the form of a metal blade;
FIG. 4 is a partial sectional view of the handle including conducting means in the form of a single metal blade;
FIG. 5 is a partial sectional view of the handle in which the metal blade of the conducting means takes the form of a spring;
FIG. 6 is a partial sectional view of the handle in which the conducting means are fixed in an opening of the handle;
FIGS. 7 a and 7 b are two sectional views of a same handle including conducting means in the form of plugging means;
FIG. 8 is a partial sectional view of the handle in which the metal blade is fixed on the plugging means;
FIG. 9 is a partial sectional view of the handle in which the distal end of the conducting means form a conductive part of a fixed part of the handle;
FIG. 10 is a sectional view, along the Y axis of FIG. 1 , of the grasping part of the handle at the position of the approach sensor in which the conducting means have a number of distal ends;
FIG. 11 is a partial view of the grasping part of the handle with a number of openings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 3 is a partial sectional view of a first embodiment of a handle according to the invention. In this figure the items identical to those of FIG. 1 carry the same reference numbers.
The handle 1 has at the outer surface of its grasping part 2 a conductive surface 5 formed by a coating, such as paint, or a conductive film made for example by metalization. The grasping part 2 is hollowed to form the housing 6 to accommodate a support module 7 . The support module 7 is formed from a plastic half-box containing an electronic card 14 carrying various electronic components 15 including a tactile sensor 8 . The various components of the support module 7 are generally protected by a resin 16 which is poured into the half-box to encapsulate them.
The housing 6 is closed by plugging means 18 made from an insulating, sealing, weather-resistant material to isolate the support module and its electronic components from external conditions. These plugging means 18 can notably take the form of a plug or a capsule.
The tactile sensor 8 mounted in the support module 7 has a detection electrode 10 to detect a user touching action.
This handle differs from the prior art handle in FIG. 1 in that it includes conducting means used to displace the active zone of the capacitive sensor. More precisely, the first end of the conducting means takes the form of a metal blade 17 carried by the plugging means 18 . The proximal end of this metal blade 17 is positioned alongside the detection electrode 10 substantially parallel to it when the plugging means are in place at the end of the housing 6 .
This metal blade 17 is then connected electrically, via a capacitive coupling or electrical conduction phenomenon, to the detection electrode 10 of the tactile sensor.
Generally, this electrical connection between a detection electrode 10 of the capacitive-type presence sensor and the conducting means take different forms; this contact can be provided by:
capacitive coupling of the sensor's detection electrode and the conducting means. The conducting means must be located near the detection electrode in order for this coupling to operate, but direct contact is not necessary. This coupling can be made for example through the protective resin encapsulating the electronic module, direct electrical connection by soldering, gluing, etc. between the sensor's detection electrode and the conducting means.
In the present case, the electrical connection is made by capacitive coupling of the metal blade 17 and the detection electrode 10 of the tactile sensor 8 , since these two parts are not in direct contact.
This metal blade 17 of which one first end is connected electrically with the detection electrode 10 has an approximately rectangular shape such that its second end emerges at the surface of the handle.
In this manner, by a capacitive coupling and electrical conduction phenomenon between the detection electrode 10 of the tactile sensor and the metal blade 17 the detection zone of the tactile sensor is displaced to a new tactile detection zone located at the outer surface of the handle. This new detection zone, represented by dashed lines in FIG. 3 , is isolated electrically from the conductive coating 5 of the grasping part 2 . This electrical isolation is achieved by using an insulating material 13 notably on the inner walls of the housing 6 and on the lateral edges of the grasping part 2 opposite the non-conductive part 3 of the handle.
In a variant of this embodiment (not shown), the metal blade 17 can comprise two metal blades in electrical contact and carried by the plugging means 18 .
FIG. 4 shows a second embodiment in which the conducting means, in the form of a single metal blade 17 , are fixed to the support module 7 . The proximal end of the metal blade 17 is fixed to the support module 7 by gluing or embedding in the protective resin 16 deposited on the support module 7 .
Advantageously, this metal blade 17 takes the form of a spring blade and has a second end which positions at the outer surface of the handle, by compression of the blade, when the non-conductive plugging means 18 are fitted in the end of the housing 6 .
As also shown in FIG. 5 , the metal blade 17 forming the conducting means and presented in the form of a spring also assists in positioning the support module 7 in the housing during fitting of the plugging means 18 and immobilizes the module 7 in the housing to prevent it moving later.
FIG. 6 shows a third embodiment of the conducting means in which they take the form of a metal insert 20 .
In the grasping part 2 of the handle there is an opening 21 joining the inner housing and the outer surface of the handle.
This opening 21 , which has a shoulder 24 , is plugged by a metal insert of reciprocal shape. The metal insert has a first end 22 positioned close to the detection electrode 10 of the tactile sensor 8 and a second end 23 which is flush with the outer surface of the handle. This metal insert 20 provides the electrical connection between the sensor's detection electrode 10 and the outer surface of the handle.
This conductive insert can be made and fitted in the opening of the handle in various ways:
directly during molding of the handle, by inserting a metal part during fabrication, by drilling the handle then fitting the metal insert.
The metal insert 20 is fixed in the opening by gluing, for example, or using fastening means such as clips. The metal insert can also be force-fitted in the opening 21 or fixed during the overmolding of the handle.
Electrical isolation of the metal insert 20 from the opening is ensured by insulating means 13 which could, for example, be incorporated in the means used to fasten the insert in the opening. Notably, the fastening glue could be electrically insulating.
The distal end 23 of the metal insert has a substantially flat surface of variable shape. This surface can notably be circular, oval or rectangular or can for example take the form of a logo representing the vehicle brand name or model.
The surface of the distal end 23 of the conductive insert 20 has a concave indent 25 approximately at its centre to identify the insert as the tactile detection zone and to ensure a more ergonomic touching action.
The electrical connection between the detection electrode 10 and the proximal end 22 of the metal insert 20 is made by capacitive coupling of these two parts. It is also possible to provide a metal blade between the detection electrode and the proximal end of the insert to make a direct conductive electrical connection.
FIGS. 7 a , 7 b show two different sections revealing detail of an additional embodiment of the conducting means.
In this embodiment, the plugging means 18 of the housing 6 in the grasping part 2 is made from electrically conductive material.
The plugging means 18 take the form, for example, of a substantially circular or square plug or capsule. A tongue is cut from the surface of these plugging means; it is held at the centre of and projects from one side of the plugging means. This tongue is bent along an axis substantially perpendicular to the longitudinal axis of the grasping part 2 of the handle towards the interior of the housing 6 . It forms a metal blade 19 which, after fitting the plugging means 18 in the opening of housing 6 , provides the coupling with the detection electrode 10 of the sensor 8 .
As seen in FIG. 7 b , the metal blade 19 is formed directly from the plugging means 18 by cutting a tongue then bending it along an axis substantially perpendicular to the longitudinal axis of the grasping part 2 of the handle. The opening 26 that appears when bending the tongue is then plugged by a sealing part to protect the electronic module from weather. In this embodiment, the plugging means 18 have an end at the surface of the handle to create a new detection zone.
The metal blade 19 is part of and is cut directly from the plugging means 18 . These plugging means 18 therefore enable, with a single part, to make an electrical connection by capacitive coupling of the detection electrode 10 of the tactile sensor and the surface of the handle. As shown schematically in FIG. 7 a , the new tactile detection zone is isolated from the conductive surface 5 of the grasping part by insulating means 13 and is located at the surface of the handle at the position where the plugging means 18 emerge. The insulating means 13 are formed from insulating material positioned on the inner walls and external edges of the housing 6 .
The plugging means 18 therefore constitute an intermediate part of the conducting means.
FIG. 8 shows a fifth embodiment of the conducting means.
In this embodiment, the support module 7 has, at its end where the housing 6 is open, conductive plugging means 18 on which are fixed a metal blade 17 . The metal blade 17 forms the proximal end of the conducting means and the plugging means 18 form the distal end of the conducting means, the whole assembly being directly attached to the support module 7 . Consequently, the conducting means are an integral part of the support module 7 .
FIG. 9 shows another embodiment of the conducting means.
In this embodiment, the part 3 of the handle fixed relative to the vehicle door is partially conductive or has a conductive coating 5 ″ on part of its surface. This conductive surface 5 ″ represents the new tactile detection zone. The detection electrode 10 of the tactile sensor 8 is displaced by capacitive coupling and electrical conduction to the position of the conductive part 5 ″ of the fixed part 3 via a metal blade 17 and conductive plugging means 18 . The plugging means 18 are positioned opposite the fixed part 3 and are in contact with it when the handle is in rest position. In this manner, a new tactile detection zone is created on the conductive surface of the fixed part. This arrangement takes account of the fact that detection of a touching action is required only for a locking command, the handle then being in rest position.
This electrical conduction from the detection electrode 10 of the tactile sensor to the new tactile detection zone is isolated from the conductive surface 5 ′ of the grasping part 2 of the handle by inserting insulating material 13 on the inner walls and the edges of the lateral opening of the housing 6 .
In this embodiment, part 3 of the handle is fixed relative to the door, but this fixed part could be fitted with a movable conductive part, in which case this movable conductive part serves as a new tactile detection zone and can notably take the form of a lock cache.
FIG. 10 shows another embodiment of invention in which the presence sensor is an approach sensor 9 .
The grasping part 2 has a housing 6 containing a support module 7 that includes an approach sensor 9 with two electrodes 10 .
The housing 6 also contains a part 27 made from insulating material overmolding conducting means in the form of a metal blade 17 . This metal blade has two proximal ends 22 positioned close to the two electrodes 10 . The blade 17 also has a distal end 23 positioned in an opening 21 penetrating the outer surface of the handle. In this manner the distal end 23 of the conducting means is flush with the outer surface of the handle.
Generalizing this arrangement, the sensor can have any number of electrodes 10 and the conducting means is formed with the same number of metal blades each including a proximal end positioned close to an electrode and a distal end emerging at the outer surface of the handle via openings.
When necessary, or in order to substantially improve the size and sensitivity of the approach detection zone, several devices like the one in FIG. 10 can be incorporated in a single handle.
This idea is schematized in FIG. 11 which represents the section of the grasping part 2 of the handle facing the door 4 .
This section has a number of openings 21 aligned parallel to a longitudinal X axis of the grasping part 2 of the handle. For each opening 21 there is a distal end 23 flush with the outer surface of the handle. For each of these distal ends 23 there are conducting means 17 associated each with at least one detection electrode 10 .
All the embodiments of conducting means used to create a new presence detection zone of a user at the handle have been described for the case of a so-called “refrigerator-type” handle, but they are quite transposable to the case of the so-called “pallet-type” handle.
The shapes of the metal blades and plugging means are in no way limitative, since other shapes or embodiments of these blades and plugging means can easily be envisaged.
The metal blade 17 has been shown in the form of a single blade, but it would be possible to make it in the form of two blades, a first blade fixed to the electronic module, for example, and a second blade attached for example to the plugging means of which one end is at the surface of the handle to establish electrical continuity with the sensor's detection electrode. As in the embodiments described above, this new detection zone is isolated from the initial tactile detection zone and possibly from the conductive surface of the grasping part of the handle.
Similarly, it is quite possible to ensure electrical continuity between a detection electrode of the presence sensor—whether it be an approach sensor or a tactile sensor—and the surface of the handle using other means or by a combination of the means described.
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The disclosure relates to a door handle, in particular for a motor vehicle, comprising at least one presence sensor having at least one electrode for detecting the presence of a user at said handle, wherein it comprises conducting means having at least one proximal end directly or indirectly connected by capacitive coupling to said detection electrode and at least one distal end emerging in electrical insulation on the outer surface of the handle so as to create at least one new zone for detecting the presence of a user. The invention also relates to a hands-free access system for a motor vehicle comprising such a door handle.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to exercise device for small animals, more particularly this invention relates to a highly effective and space efficient device for allowing small confined animals to obtain the exercise they need for their optimum health, while not requiring the confined environment of such small animals beyond the physical dimensions of those which are traditionally and typically well accepted.
[0003] 2. Previous Art
[0004] Past rodent or small animal exercise devices have proven at least somewhat successful. The animal can get some exercise and increase its health and life span. Consequently, the animal's owner benefits from a healthy animal with greater life span and lower maintenance costs.
[0005] The exercise devices are used extensively by healthy animals. For example, the animals have been observed to spend two or more hours of actual running time on the wheel per day providing that the exercising does not callus or otherwise abraid their feet or damage them in other ways. On the other hand, when exercise damages or hurts the animal in some way, there is considerably less exercise by the animal. Since the exercise is strictly voluntary, an exercise device must be comfortable for the animal to use to obtain the desired benefits.
[0006] It will also be appreciated by those familiar with rodents that these animals are nocturnal and typically exercise at night when their owners aren't present. That means if the animals damages itself, it must wait sometimes many hours before any assistance will be available. In many cases this can result in permanent injury and in some cases, it can be fatal to the animal.
[0007] Such past devices have included what is typically known as a “hamster wheel” depicted in prior art FIGS. 1 and 2 and set forth as numeral 20 . The hamster wheel 20 rotates while connected to a frame 22 . The frame and wheel are situated in the animal's environment, typically a cage. Thus, the physical dimensions of the exercise device must be small enough to fit within the cage while large enough to accommodate the exercise for which they were intended.
[0008] The wheel 20 has what is known as an open structure wherein the wheel is in the form of a screen as shown clearly in FIGS. 1 and 2. Typically, the animal's appendage, e.g. a foot, can get caught in the screen. If the wheel 20 is spinning rapidly during exercise catastrophic injury can result. Such injury can include a broken foot or leg damaged so severely that amputation (either Veterinarian assisted or self imposed) would be required to save the animal's life. Amputation can costs hundreds or even thousands of dollars. Needless to say not every pet owner has such readily available cash. In such cases, despite the love and caring that owners may well feel for their animals, the animal's death is a likely result.
[0009] Exercise also benefits the animals because it presents a challenge and a learning experience. Early on, an animals may be frightened by the device and gradually when it sees other similar animals using the device, it may start to learn how to use it. After using it for some time, the animal may well become quite skilled at using the device and have a positive outlook toward itself and other inhabitants of its environment and toward its owner(s).
[0010] Another constraint of the exercise device is that it be small enough to fit in the door opening of the animal's confined environment or cage. Typically, the exercise device must fit through the animal's cage door. Very few cages have a removable sides or a top or a bottom. Most such cages have only a hinged door and the exercise device must be sufficiently small to fit through such a door. The larger wheels tend to function better and are preferable to the animals because they allow better exercise.
[0011] Cages tend to be from 12 inches in height by 16 inches in width and length to 18 inches in height by 24 inches in width and length. The physical dimensions of the wheel 20 must be such to allow it to fit within the cage. The wheel 20 tends to be 12 to 14 inches in diameter and typically provides a running surface having a width of approximately 4 to 5 inches. It is preferable to have a such a wheel 20 to provide an adequate surface for the animal to exercise on without arching its back or interfering with its normal running or trotting movement. Clearly, using the past construction of the wheel 20 , at least one dimension of the cage would need to the diameter of the wheel in order to fit the wheel within the cage. This is true since typically none of the top, sides or bottom are removable. It is not impossible to force fit smaller cages with a larger wheel using the present configuration of the wheel 20 .
[0012] As will be appreciated from FIGS. 1 and 2, the wheel 20 , in effect, includes a ceiling which limits the size of an animal on the wheel, in addition to the other deficiencies previously discussed. Additionally, in order to perform exercise in the opposite direction, the animal typically disembarks from the wheel 20 and turns around
[0013] What is needed is a small animal exercise device which will allow the animal to exercise in safety and comfort. Also, the device should fit easily into even small cages, if possible, without disassembly. The exercise device should provide an effective radius of exercise great enough to accommodate the animal's exercise needs.
SUMMARY AND OBJECTS OF THE INVENTION
[0014] It is an object of the present invention to provide a small animal exercise device, which enables a rodent to obtain exercise safely.
[0015] It is an object of the present invention to provide a small animal exercise device which allows a rodent or similar small animal to exercise without the risk of sustaining injury to its limbs during the exercise.
[0016] It is an additional object of the present invention to provide a small animal exercise device, which can be easily fit into even a small cage while providing the animal with a device large enough for its exercise needs.
[0017] It is an additional object to provide such a small animal exercise device, which is suitable for a variety of small animals including most small rodents.
[0018] It is an additional object to provide such a small animal exercise device, which provides the small animal with an exercise and a learning experience.
[0019] In accordance with the aforementioned objects and those that will be mentioned and will become apparent below, a small animal exercise device according to the present invention comprises:
[0020] a dish having a surface suitable for rodent exercise, the dish having an outer periphery and a raceway suitable for rodent exercise adjacent the outer periphery, the raceway suitable for animal exercise and defining a solid surface;
[0021] a stand for connection with the dish, the stand having a proximal and a distal end, the proximal end serving as a base and the distal end for connection with the dish, such that the dish is rotates freely under rodent exercise; and
[0022] a connecting assembly for rotatably connecting the dish to the stand,
[0023] whereby, rodent exercise occurs on the solid surface of the raceway.
[0024] In an exemplary embodiment of an exercise device according to the present invention, the base rests upon a horizontal surface and the dish is elevated above the surface to allow the dish to rotate freely under small animal exercise. Additionally, the dish makes an angle with the horizontal surface of approximately 60° (β).
[0025] In another exemplary embodiment, the angle the dish makes with the horizontal surface upon which the stand rests is adjustable.
[0026] In another exemplary embodiment of a rodent exercise device according to the present invention, the dish is shaped such that it forms an angular shape (a) between 80° and 150° and in a preferred embodiment the angular shape is approximately 120°.
[0027] Another exemplary embodiment of a rodent exercise device according to the present invention includes an inner section defining a frusto-conical shape. The stand is connected to the dish at the inner section.
[0028] Also in accordance with the above objects and with those that will be mentioned and will become apparent below, a rodent exercise device in accordance with the present invention comprises:
[0029] a dish having a surface suitable for small animal exercise, the dish having an outer periphery and a raceway suitable for small animal exercise adjacent the outer periphery, the raceway suitable for small animal exercise and defining a solid surface and the dish inner zone suitable for animal exercise defining a frusto-conical shape, the inner zone having an opening;
[0030] a stand for connection with the dish, the stand having a proximal and a distal end, the proximal end serving as a base and the distal end for connection with the dish, such that the dish is rotates freely under small animal exercise; and
[0031] a connecting assembly for rotatably connecting the dish to the stand at the inner zone and each of the connecting assembly and the inner zone having an opening for accommodating the stand,
[0032] whereby, small animal exercise occurs on the solid surface of the raceway.
[0033] In other exemplary embodiments of a rodent exercise device according to the present invention, the dish is perforated.
[0034] An advantage of the-present invention is that an exercise device is provided for small animals which enables them to exercise to obtain health benefits with significant risks of serious injury.
[0035] Another advantage of the present invention is to provide an exercise device for small animals which fits within a small confined area and provides a more than adequate surface for exercise.
[0036] Another advantage of the present invention is to provide an exercise device which is usable for a broad range of small animals since the exercise device in accordance with this invention does not have a ceiling limitation.
[0037] Another advantage of the present invention is to provide an exercise device which allows an animal to turn around on the exercise device without dismounting.
BRIEF DESCRIPTION OF THE DRAWING
[0038] For a further understanding of the objects and advantages of the present invention, reference should be given to the following detailed description, taken in conjunction with the accompanying drawings, in which like parts are given like reference numerals and wherein:
[0039] [0039]FIGS. 1 and 2 are exemplary embodiments of prior rodent exercise devices.
[0040] [0040]FIG. 3 is a perspective view of an exemplary embodiment of a small animal exercise device in accordance with this invention.
[0041] [0041]FIGS. 4 and 5 are exploded perspective views of an exemplary embodiment of the small animal exercise device in accordance with this invention.
[0042] [0042]FIG. 6 perspective view of the small animal exercise device in accordance with this invention illustrating in the effective overall radius of the device.
[0043] [0043]FIGS. 7 and 8 are partial perspective views of small animal exercise device in accordance with this invention.
[0044] [0044]FIGS. 9 and 10 illustrate the dish being position at different relative angles to the horizontal.
[0045] [0045]FIG. 10 illustrates an exemplary embodiment of the rodent exercise device according to the present invention in use.
DETAILED DESCRIPTION OF THE INVENTION
[0046] For the animal to perform its exercise in its enclosure, it must do so in place, as with using the device of the instant invention, the animal is untethered and moves in place along an endless incline plane. Prior art wheels, such as wheel 20 illustrated in FIGS. 1 and 2, also provided such a plane. The wheel 20 rotates around a center axis and is supported by a stand resting on the floor of the cage or animal enclosure or sometimes attached to the sides of the cage or animal enclosure.
[0047] The wheel 20 is attached to its center axis by spokes or a sidewall. The inclined surface is thus provided in front of the animal on an endless basis during exercise. Assuming, as is typical, that the wheel 20 is evenly balanced or at least generally circular, the lowest energy or start position for exercise is when the center of mass of the animal is directly below the center axis of the wheel 20 . When the animal moves forward along the endless incline, gravitational force expressed as a moment of force causes the wheel to rotates in an opposite direction. The same is true for each successive step. Thus, the animal, as noted above, remains stationary while obtaining the desired exercise.
[0048] The invention will now be described with reference to the drawing and most particularly to FIG. 3, which illustrates a perspective view of an exemplary embodiment of a rodent exercise device according to the present invention generally denoted by the numeral 50 . The rodent exercise device 50 includes a dish 52 , a stand 54 and a connecting assembly 56 .
[0049] The dish 52 provides a solid surface for the rodent to run or exercise upon. The dish 52 has an outer periphery 58 defining a raceway 60 . As will be described more fully hereinafter the rodent runs on the raceway 60 and the effective exercise is much greater than the actual diameter of the dish.
[0050] With respect to FIGS. 4 and 5, there is illustrated the stand 54 having a proximal end 62 and a distal end 64 . The proximal end 64 serves as a base 66 and the distal end 64 defines a bearing axle 68 for facilitating rotatable connection with the dish 60 .
[0051] The connecting assembly 56 includes a bearing assembly, generally denoted by the numeral 70 . The bearing assembly 70 includes a limiter 72 , a first and a second bearing 74 and 76 , respectively, a center disk 78 and a locking nut 80 . The limiter 72 includes a locking screw (not shown) for correctly positioning the dish on the bearing shaft 68 . The locking screw may be adjusted for re-positioning the limiter 72 and therefore the dish 52 on the bearing shaft 68 .
[0052] The first bearing 74 defines a flanged bearing with its flanged end in abutting contact with the limiter 72 and being threaded on the bearing shaft 68 after the limiter 72 has been properly positioned to the desired location. The dish 52 has an center opening 82 through which the bearing shaft 68 is threaded. The center disk 78 also includes a center opening 84 aligned with the center opening 82 of the dish 52 . The second bearing 76 also defines a flanged bearing and is threaded on the bearing shaft 68 in opposed relation to the first bearing 74 . The bearing shaft 68 in a preferred embodiment has a threaded distal end. The locking nut 80 is threaded over the threaded distal end with the flanged portion of the second bearing 76 in abutting relation to the locking nut 80 .
[0053] As will be appreciated, the exercise device in accordance with this rotate on and is supported by the two bearings 74 and 76 . It has been observed that two bearings work better than one. Additionally, the wider the separation between the bearings 74 and 76 , the more stable the device will be and the less wear producing torque will be exerted on the bearings.
[0054] The stand proximal end 62 defines a base 84 upon which the device 50 rests as clearly illustrated in FIGS. 3 - 5 . The base 84 rests upon a horizontal surface and elevates the dish 52 so that it can rotate freely during animal exercise. The base 84 is angled sized and shaped to provide elevation and stability during animal exercise.
[0055] The dish 52 has a generally parabolic shape expanding outwardly and includes two basic portions, a outer zone 86 and an inner zone 88 as clearly shown in FIGS. 9 and 10 as well as the other Figs. in the drawing. The shape is defined by a curvature of between 100° and 140°. In other words, taking the lines 90 formed by the cut-away portions of the dish in FIGS. 9 and 10 and extending them until the meet will cause an angle α of between 80° and 150°. However, it is also believed that the preferred angle α is approximately between 120° for the reasons given herein.
[0056] The dish having an angle of curvature of 120° is preferred because it will accomplish the objects of the invention and tend to maximize the efficiency of space and animal exercise. Additionally, such an angle of curvature and those within the range from approximately 80° to 150° will accommodate an animal larger than will that of the prior art device 20 having comparable radius because there is no height restriction since there is no effective ceiling in the exercise device in accordance with the invention and because there are no side walls and the like to restrict the animal's movement. Additionally, the dish 52 provides a running path that allows the animal exercising to reverse direction without dismounting from the device.
[0057] To change directions in the prior art wheel 20 , the exercising animal had to dismount, reverse direction-and remount. In many cases using the prior art wheel 20 , the exercise surface width is inadequate, for example, if the animal's owner is unable to get a larger wheel into the cage, the animal fur is likely to rub its fur against the spokes or side-wall causing damage. The value of many of these animals is dependent on the color and quality of the fur.
[0058] The dish 52 provides a non-vertical sidewall with no spokes or obtrusive vertical sidewalls to cause damage to the animal or its fur. Since the axis of the dish is at 60° degrees from horizontal, the center portion of the disk slopes away from the exercise surface at 150°, providing ample room for the animal to exercise freely and to reverse direction without dismounting.
[0059] The 120° degree dish 52 provides a suitable inclined surface in front of the animal on which to perform work and ample space in every direction for the animal to be comfortable. As the dish or cone apex angle decreases from 120° to 80° or 90°, for example, the slope increases and the room around the animal decreases. An 80° or 90° dish 52 still allows an animal larger than a prior art device of like radius, however not as large as an animal as the 120° dish would accommodate.
[0060] As the angle increases past 120°, the slope of the surface in front of the animal effectively decreases and thus the ability to perform work in place also decreases.
[0061] Additionally, the 120° dish with a 14 inch diameter will fit through a cage door measuring 10″×10″ or 9″×12″ or larger because the angle allows for greater manipulation of the device into the animal enclosure.
[0062] The 120° dish is a more flexible configuration than, for example, a 14 inch dish with an angle of 90°. The 90° dish will fit through a 10×10 door opening. However, the same dish will have difficulty fitting through a 9×12 opening.
[0063] Devices with an angle of greater than 120° and up to 150° will function reasonably well although the inclined plane in front of the animal decreases as the angle increases. Devices with an angle greater than 120° will fit through the same sized door openings as the 120° dish. Since the device must be mounted so the exercise path is horizontal, the 140° to 150° dish will take up considerably more cage floor space than the 120° dish.
[0064] The 14 inch dish is adequate for animals up to approximately 2 ½ pounds. The exercise device in accordance with the invention may be scaled up or down, while still creating the same benefits over comparably sized prior art devices.
[0065] [0065]FIGS. 9 and 10 also illustrate the curvature of the distal end 64 with respect to horizontal. As shown in FIGS. 9 and 10, the angle β can vary. It has been found that angle β is preferably around 60°.
[0066] The inner zone 88 of the dish 52 defines a frusto-conical shape also clearly shown in the cut away figures of FIGS. 9 and 10. A perspective view of the inner zone 88 is shown with respect to FIGS. 7 and 8. A slight modification to the center portion of the 120° dish permits an increase in the distance between the bearings 74 and 76 , over what would be available if the device were a 120° dish only. This modification does not unfavorably impact on fabrication cost, still yields an adequate width of exercise surface and allows the dish to fit into standard cages more often.
[0067] The dish 52 is made using a metal spinning process. It will be appreciated that a metal stamping or similar process may well be used within the spirit and scope of this invention to make the dish 52 . A circular disk of metal is rotated at a high speed and formed to the desired pattern. Typically, the exemplary materials for the dish 52 are aluminum and galvanized steel. It will be appreciated by those familiar with such exercise devices that almost any having malleable characteristics may be used. It will also be appreciated that materials such as wood or plastic should be avoided since rodents and similar small animals will find them appetizing and eat them.
[0068] Typically the opening 82 is a ⅞″ hole punched in the center for receiving the second flanged bearing 76 .
[0069] The center disk 78 is similarly made using a metal spinning process and likewise is made from similar materials. In an exemplary embodiment, the center disk 78 is permanently attached to the dish 52 by three or four rivets.
[0070] Effective Radius of Dish:
[0071] Upon observation, the rodent will run only on the outer surface of the dish 52 , adjacent the periphery of the dish 52 . This running space is defined as the raceway. It will be appreciated that the raceway defines a solid surface to facilitate safe exercise and a proper gripping surface for the rodent.
[0072] With respect to FIG. 6, there is shown the effective distance of the running surface or raceway. In other words, the effective radius of the dish 52 for facilitating the exercise of the animal. For example, in an exemplary embodiment, the dish 52 has a radius of 7 ″. However, because the rodent only runs in a vertical plane, a larger radius is really what controls the dimension.
[0073] To determine the actual effective radius of exercise an expandable hoop 100 shown in FIG. 6 is employed. First the hoop 100 is expanded until it has a diameter of 24 inches (radius equals 12 inches). The hoop is held in the vertical plane and placed so that it contacts the surface of the dish approximately {fraction (11/2)}″ in from the dish 52 edge, the periphery where the animal runs. This demonstrated the effective distance or diameter of the dish 52 . An actual 7″ diameter results in an effective 12″ striding or exercising diameter for the animal.
[0074] In Use:
[0075] The rodent or small animals stride on the dish 52 is not what the animal would normally use in the wild. In the wild, the rodent would push off the terrain and its head and body would typically bounce up and down. As can be appreciated, the rodent dodges from side to side in the wild to avoid being a predator's meal. Since no such hazards exist in a the confined environment, the idea is to give the rodent or other small animal a smooth running surface to afford the rodent the ability to safely get effective and health promoting exercise.
[0076] It is known by those familiar with rodents that typically, rodents exercise in bursts. When the rodent runs or jumps it activates most of their body muscle mass. This is the same type of exercise desired to be achieved by the device 50 .
[0077] The rodent must learn to properly use the device 50 . Since this is not within its normal exercise, there is a learning curve which upon testing was quite easily done by most rodents. The rodent jumps onto the dish 52 and may well jump off the first several times. Once the rodent finds a comfort level on the dish 52 , it will attempt to rotate the dish 52 . Again, it may take several attempts before the rodent learns how to spin the dish effectively and comfortably.
[0078] The rodent makes adjustments in its stride to compensate for running on the dish 52 . Additionally, since the dish 52 can be adjusted the rodent must also make compensations for the various sized different arcs, depending upon the angle (β angle) that the dish 52 makes with the horizontal. In an exemplary embodiment, the β angle can be adjusted within the scope of this disclosure.
[0079] It should be noted that if the device is significantly smaller than the animal's stride, the animal will need to make significant adjustments to keep from either jumping or crashing into the dish 52 . Typically, the animal will curtail its normal tendency to spring forward at the end of its stride.
[0080] If the device's effective radius is significantly greater than the animal's stride, the animal will have a tendency to bounce up in the middle of the stride and the animal would lose contact with the device and hence control. While this type of stride works well in the wild, it does not allow the animal to maintain control and sound footing on the dish 52 . To maintain control and sound footing, the animal adjusts its stride. The animal decreases the pushing force in the mid-portion of the stride. The cadence of the animal's stride decreases, less and a smoother force throughout the stride is used.
[0081] In another exemplary embodiment, the raceway 60 has concentric grooves and another embodiment has textured ridges. While it is believed most beneficial to provide a smooth surface for animals and especially rodents having pads, some animals may well prefer a textured surface to run upon and the invention in accordance with this disclosure embraces such embodiments. The smooth surface is illustrated with respect to FIG. 3, while the concentric grooves embodiment is illustrated with respect to FIG. 7 and the textured surface is illustrated with respect to FIG. 8.
[0082] Another advantage of the device 50 in accordance with this invention is that even young rodents, such as chinchillas a week and half old may use the device 50 safely. In fact, prior art exercising devices, illustrated in FIGS. 1 and 2 are removed from the cages of such young rodents to prevent serious or even fatal injury. While such young rodents have larger feet than babies, they still have a serious risk of having their feet caught in the wire mesh of the prior art exercising devices. With the solid surface of the dish 52 , the young rodent or similar animal can run safely.
[0083] While the foregoing describes several embodiments of a rodent and small animal exercise device in accordance with the present invention, it is to be understood that the above description is illustrative only and not limiting of the disclosed invention. It will be appreciated that it would be possible for one skilled in the art to modify a number of aspects of the small animal exercise device within the spirit and scope of the invention. Additionally, the dimensions set forth in the foregoing description are illustrative and may be modified within the spirit and scope of the invention. In particular, for example, the dimensions of the animal enclosure as well as the exercise device itself may be altered as needed to accommodate anticipated loads. Accordingly, the present invention is to be limited only by the claims as set forth below.
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Disclosed is a small animal exercise device, suitable for allowing a small rodent or other small and trainable animal to be domesticated, and confined in a relatively small space while enjoying the benefits of exercise that accrue to mammals of all kinds. The exercise device includes a dish, a stand and a connecting assembly. The dish provides an effectively large and safe exercise surface, while physically fitting into the confined environment or small enclosure for small animals such as rodents and the like. The dish has an outer periphery and a raceway having a solid surface adjacent the periphery. The dish is rotatably connected to a stand, which elevates the dish above the horizontal surface upon which the stand rests, to allow the dish to rotate freely during rodent or other small animal exercise. The connecting assembly, includes among other things, a bearing assembly which fixedly, but rotatably connects the dish to the stand, more particularly, the distal end of the stand defines a bearing shaft. The bearing assembly allows rotation of the dish while being attached to the shaft and includes a limiting member for properly positioning the dish on the shaft which allows free rotation of the dish.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to sheet handling systems. It has particular applicability to sheet handling systems for use in fused image printers and copiers.
2. Description of Related Developments
In a transfer electrostatographic process such as conventional transfer xerography, in which an image pattern of dry particulate unfused toner material is transferred to a final image support surface, e.g., a copy sheet from an initial image bearing surface, e.g., a charged photoreceptor surface developed with toner, the transferred toner is typically only loosely applied to the final image support surface after transfer, and is easily disturbed by the process of stripping the final image support surface away from the initial support surface and by the process of transporting the final image support surface to the toner fusing station. The final image support surface preferably passes through a fusing station as soon as possible after transfer to fuse the toner image permanently onto the final image support surface, thereby preventing smearing or disturbance of the toner image by mechanical agitation or electrical fields. For this reason, and also for the reasons of simplifying and shortening the paper path of the copier, it is desirable to maintain the fusing station as close as possible to the transfer station. A particularly desirable fusing station is a roll-type fuser, wherein the copy sheet is passed through a pressure nip between two rollers, at least one of which is heated and at least one of which is resilient.
However, when such a fuser roll nip for the final image support surface is located close enough to the transfer station so that a lead portion of the final image support surface can be in the fuser roll nip simultaneously with the rear or trailing portion of the same final image support surface still being in contact with the photoreceptor, smears or skips in the unfused toner image, which is being transferred to the trailing portion of the final image support surface, can occur. This condition is caused by relative movement or slippage between the initial support surface and the final image support surface in those areas where they are still in contact, i.e., those areas of the final image support surface which has not yet been stripped away from the initial support surface. A source of such slippage is a speed mismatch between the nip speed of the fuser rolls (the speed at which the fuser is pulling the lead edge of the paper through the fuser) relative to the surface speed of the initial support surface. If the fuser nip roll is slower, the final image support can slip backwards relative to the initial image support surface. If the fuser roll is faster, the final image support material can be pulled forward relative to the image on the initial support surface. In either case, this can cause the aforementioned smears or skips in the toner image to be transferred to the trailing area of the final image support or to cause image elongation.
An exactly equal velocity drive connection between the initial support surface and the fuser rolls is difficult to maintain. Also, there is a further complication that the actual sheet driving velocity of the fuser nip roll can change with changes in an effective diameter of the driving roll in the nip. This can occur from replacement of the rollers or changes in the resilient deformation of the rollers due to changes in applied nip pressure, material aging, temperature effects, etc. Thus, equal speed is difficult to maintain between a fuser nip roll and the photoreceptor surface in commercial printing apparatus and can require increased maintenance and the need for speed adjustment mechanisms.
In order to overcome these problems, three basic design approaches have been taken. The first is to allow enough paper path distance between transfer and fusing to accommodate most paper sizes with minimum disturbance to unfused toner particles. This solution has the effect of increasing the length of the paper path, thereby requiring the copier to occupy a large floor area. This is disadvantageous, especially to customers having limited space availability or having high floor space costs.
A second approach is to use complex paper paths with special transports. This solution is undesirable because it adds cost to the equipment and introduces potential sources of maintenance requirements and unreliablity.
A third approach is to use buckle chambers between the transfer station and the fuser so that speed mismatches between the transfer station and the fuser rolls can be accommodated by the portion of the image support surface that is in the buckle. U.S. Pat. No. 4,017,065 shows one such buckle arrangement. In the designs disclosed in this patent, the image surface is formed in a buckle by being drawn, by vacuum, against a guide surface. The fuser roll nip is intentionally driven at a different speed than the transfer speed to form a buckle. The buckle is controlled by cyclic reductions in the vacuum applied to the guide surface. Another approach is shown in U.S. Pat. No. 4,941,021, wherein a buckle is formed by controlling the speed of the fuser rolls so that the image support surface travels more slowly through the fuser rolls than through the transfer zone. This system requires sensing of the buckle to maintain the size of the buckle within predetermined limits. Such sensing systems add manufacturing cost and require maintenance, as dust and dirt within the equipment can interfere with sensing, particularly when optical detectors are used.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a sheet transport system with matched speeds between adjacent workstations.
It is a further object of the invention to provide a sheet transfer system wherein the path length is minimized.
It is an additional object of the invention to provide a sheet handling system having a reduced cost and increased reliability.
It is a further object of the invention to improve the image quality in fused toner printing systems.
These and other objects of the inventions are achieved by the use of a sheet handling system with a transport section offset from a linear path between adjacent workstations. Image support sheets are drawn against a sheet transport surface by vacuum. A pressure sensor is arranged to sense the vacuum within a plenum associated with the transport surface to detect separation of the sheet from the transport surface resulting from tension in the sheet. The separation is indicative of the speed differential between downstream and upstream workstations. The signal from the pressure sensor is used to reduce or eliminate this speed differential.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 schematically illustrates a printing system embodying the invention;
FIG. 2 illustrates separation of the copy sheet from the sheet receiving surface of the sheet transport;
FIG. 3 illustrates an embodiment employing a top transport arrangement;
FIG. 4A illustrates another embodiment of the invention utilizing a deflector and showing the position of a sheet just as the lead edge reaches the fuser station; and
FIG. 4B illustrates the embodiment in FIG. 4A just after the leading edge of the copy sheet has been engaged in the nip of the fuser rolls.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 schematically illustrates a portion of printing equipment, such as a xerographic copier. In this arrangement, fused toner images are formed on a image support, such as a copy sheet C. In this process, an unfused toner image is first formed on the upper surface of the sheet C at the transfer station 10. As is conventional, a photoreceptor in the form of a drum 10a or a belt, is arranged to transfer unfused toner particles from the imaged photoreceptor to the upper surface of copy sheet C by electrostatic attraction created by, for example, a corotron 10b. The particular manner in which the toner image is formed on the photoreceptor and transferred to the copy sheet C is not a part of this invention and further description is not necessary, other than to indicate that such systems are widely known.
The copy sheet C is driven in the direction of arrow 11 by the moving surface of the photoreceptor drum 10a or by a supporting belt 11, that is driven by a motor driven roll 11a or other suitable drive system (not shown) at a preset speed.
The copy sheet C travels in the direction of arrow F to transport station 12 downstream from the transfer station 10. The transport station 12 has a sheet receiving surface, such a foraminous belt 14 trained over rollers 16, at least one of which is driven by a motor or driving system (not shown). The belt 14 is driven at a speed substantially equal to the speed of copy sheet C in transfer station 10. At least a portion of the belt 14 is offset from or spaced from a line P, that is linear path between the transfer station 10 and the nip of the fuser rolls 28, 30. A plenum 18 communicates with the upper surface of the belt 14 so that the copy sheet C is drawn against the belt 14. A fluid conduit 20 extends from the plenum 18 to a pressure sensor 22, such as a pressure switch or pressure transducer so that the vacuum within the plenum 18 can be sensed. Alternatively, the pressure switch or transducer can be located in plenum 18. The vacuum in the plenum 18 changes as a result of the amount of the surface area of copy sheet C adhered to the foraminous belt 14 by the vacuum. For example, if the copy sheet C covers the portion of the belt 14 overlying plenum 18, thereby sealing the openings in the belt 14, the vacuum is high. However, if the copy sheet C is drawn away from or separated from the belt 14, as will be explained later, the vacuum within plenum 18 is reduced.
The electrical signal from the transducer 22 is supplied to a microprocessor 24 that can comprise the main controller for the printer/copier or a dedicated microprocessor. The microprocessor 24 includes processing routines for controlling the speed of a stepper or servo motor 26 for driving one of the fuser rolls 28. The control function can be implemented by, for example, a look-up table, with empirically determined values, for decreasing the motor 26 speed in proportion to the amount of the vacuum drop sensed by sensor 22. Such control routines are within the programming skills of machine designers and no further detailed explanation is necessary.
The amount of surface area of the copy sheet C from the surface of the belt 14 is a function of the difference in speed imparted to the copy sheet C at the transfer station 10 and by the fuser rolls 28, 30. Prior to the arrival of the leading edge of each successive copy sheet C, the drive speed of the motor 26 is initialized at a value such that the fuser rolls 28, 30 impart a higher speed to the copy sheet C than that imparted at the transfer station 10 and by belt 14. The higher initial speed can be set as a result of the detection of the absence of a copy sheet in the fuser nip by a suitably positioned sensor 36. As a result of the higher initial speed, when the lead edge of the copy sheet C is first engaged in the nip of the rolls, the sheet is tensioned and separates from the belt 14 over a length L, as shown in FIG. 2. The exposure of belt 14 to ambient conditions results in a decrease in the vacuum level within plenum 18. A signal representative of the pressure differential sensed by the transducer 22 is supplied to the microprocessor to decrease the speed of motor 26 slightly, which results in a lessening of the tension imparted to the copy sheet C and a decrease in the length of exposed belt L. Ideally, the control speed of motor 26 is controlled so that substantially all of the upper surface of belt 14 is engaged by the copy sheet S, as shown in FIG. 1. The speed is constantly adjusted until the trailing edge of the copy sheet C clears the transfer zone. In this manner, the speed imparted to the copy sheet C by the fuser rolls 28, 30 is brought to a level to closely match the speed imparted to the copy sheet at the transfer station 10, thereby avoiding disturbance of toner transfer at the transfer station 10.
In a second embodiment, the transducer 22 can comprise a pressure switch having an on-off state in a range designed to maintain the copy sheet C against belt 14, as shown in FIG. 1. In this embodiment, the switch 22 is connected to motor 26 through a lead 34 to turn the motor 26 on and off. When the vacuum in plenum 18 increases to the "on" set point of the switch, the motor 26 is activated to drive fuser rolls 28, 30 and the copy sheet C is drawn away from belt 14. Conversely, when a high vacuum exists in plenum 8, indicating the length L is reduced, the switch 22 deactivates motor 26, allowing the copy sheet to be separated from a portion of the belt 14. The speed profile of the motor 26, which ramps up and ramps down as the motor is cycled on and off by pressure switch 22, imparts an average drive speed to rolls 28, 30, thereby maintaining the desired amount of buckle in the copy sheet C. This control arrangement has the advantage of eliminating the servo algorithms implemented by microprocessor control, as used in the previously described embodiment.
In another embodiment, illustrated in FIG. 3, the transport system 12 is located in an upper position immediately adjacent a transfer or photoreceptor drum 38 which conveys the copy sheet C. The copy sheet C may be adhered to the surface of the drum by known techniques, for example electrostatic tacking. Elements common with FIG. 1 are like numbered. The copy sheet C is separated from drum 38 by known means, for example, a separator 40, and is drawn against the foraminous belt 14. The copy sheet adheres to the belt 14 and is carried toward the exit end of the transport station 12. A deflector 42 is positioned downstream of the end of belt 14. The deflector 42 deflects the leading edge of copy sheet C away from the straight path P 1 toward the nip of fuser rolls 28, 30. As shown, the nip of rollers 28, 30 is offset downwardly from the path P 1 .
This embodiment operates in substantially the same manner as the FIG. 1 embodiment. That is, the speed of the rollers 28, 30 is in initialized to impart a higher speed to the copy sheet C than the drum 38 and transport 12, thereby initially causing the copy sheet C to be tensioned and separated from the belt 14. The vacuum in plenum is sensed to control the speed of roller 28 so that, in a steady state condition, the copy sheet C follows a path substantially as shown in FIG. 3.
FIGS. 4A and 4B show another embodiment of the invention wherein the foraminous 14 of the transport 12 is arranged substantially parallel and coincident with the path P, which extends between the nip of the roller 28 to 30 and a downstream transfer station (not shown). Elements common with the FIG. 1 embodiment are like numbered. In this arrangement, a deflector 42' is arranged at the downstream end of the belt 14 to deflect the leading edge of the copy sheet C away from the path P by a slight distance D. As the leading edge of the copy sheet C advances toward the fuser rollers 28, 30, it is located distance D above the path P but is then urged downwardly by the roller 28 into the nip formed by rollers 28, 30. As in the previous embodiments, the rollers 28, 30 are initialized at a speed that imparts tension on a copy sheet C. As a result, as the leading edge of the copy sheet C is engaged in the nip of rollers 28, 30 the sheet is tensioned over the deflector 42' and a portion of the copy sheet C is lifted from the belt over a length L as shown in FIG. 4B. As the sheet C separates from the belt 14, the vacuum in plenum 18 is reduced and can be sensed to control the speed of rolls 28, 30 as in previous embodiments.
Although, in the foregoing description, the speed of fuser rolls 28, 30 is controlled, similar results can be achieved by controlling the copy drive speed at transfer station 10 (via belt 11 or drum 38) and transport station 12 (via belt 14) relative to the speed of the fuser rolls 28, 30.
As can be seen from the foregoing, a reliable and cost effective system is provided for controlling transport of that copy sheet. The system can be easily integrated into existing system architectures.
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A sheet transport system incorporating a control for matching drive speeds imparted to a sheet extending between adjacent workstations is disclosed. The copy sheet is engaged by a receiving surface disposed between the workstations and is adhered to the receiving surface by vacuum. The copy sheet follows a path offset from a linear path extending between the workstations. Fuser rolls are driven at a slightly higher speed to tension the copy sheet and lift it from the transport surface. The lifting is detected by a sensor for sensing the vacuum in a plenum communicated with the receiving surface. The drive speed of the fuser rolls is controlled in accordance with the signal from the sensor.
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This application is a continuation-in-part of and claims the benefit of priority from PCT application PCT/EP2011/070366 filed Nov. 17, 2011 and German Patent Application DE 10 2010 052 010.1 filed Nov. 19, 2010, the disclosure of each is hereby incorporated by reference in its entirety.
BACKGROUND
The invention concerns a device for dry-forming a fibrous web.
For the production of nonwovens it is known that the fibers are deposited by means of an air flow onto a deposit belt to form a fibrous layer. This method, typically referred to in the field as an airlaid method is based on the fibers or fiber mixtures being deposited such that they are uniformly distributed by means of a forming head onto the upper surface of a deposit belt. The zone covered by the forming head on the deposit belt is normally referred to as the forming zone, in which the fibers are joined on the deposit belt.
A device of this type is known, for example, from EP 0 006 696 A1.
With the known devices, a plurality of fibers or fiber mixtures is supplied by means of an air flow to a forming head. Means are provided within the forming head for mixing and distributing the fibers. A forming outlet is formed on the bottom surface of the forming head, which is typically disposed at a short spacing above the deposit belt. As a result, an empty space is formed between the forming head and the deposit belt, which serves for the supplying of a fiber flow exiting the forming outlet. The depositing of the fibers onto the deposit belt is supported by a suction device, which receives and discharges the air from the fiber flow. The fibrous layer formed on the upper surface of the deposit belt is continuously transported out of the forming zone via the deposit belt, such that a fibrous layer is obtained, which is subsequently supplied to a further processing, such as a solidification process, for example.
The depositing of the fibers is substantially determined by the air flow generated in the forming zone. With the known device, the forming head is on the entry end of the deposit belt, and sealing means in the form of sealing rollers are disposed at the output end of the deposit belt, respectively, in order to shield the empty space formed between the forming outlet and the deposit belt from the surrounding environment. The sealing rollers work together with housing components disposed on the longitudinal surfaces of the deposit belt in order, thereby, to prevent the entry of secondary air flows from the surrounding environment. In practice, however, it has been the case that depending on the type of fiber, and the size of the fiber, irregularities arise in the depositing of the fibers, which are referred to as so-called cloud formations. In this respect, it is believed that the suction flows generated by the suction device may lead to irregularities in the fiber deposit.
In order to eliminate irregularities of this type in the depositing of the fibers, it is known, for example, from WO 2006/131122 A1, to influence the suction flow of the suction device in sub-sections of the forming zone. With the known device, a baffle is associated with an entry end of the forming zone of the suction device, which influences the suction flow beneath the deposit belt. As a result, air turbulence at the entry end of the forming zone, in particular, which occurs as a result of secondary air from the surrounding environment being suctioned into this area, is prevented. As a result, however, varying suction flows occur in the forming zone, which lead to differing deposit behaviors of the fibers within the forming zone.
SUMMARY
It is thus an objective of the invention to create a generic device for the dry-forming of a fibrous web, with which a high degree of uniformity in the fiber distribution within the fibrous layer can be obtained.
This objective is attained in accordance with the invention by disposing a sealing means at the entry end in relation to the deposit belt to form an entry opening having an adjustable inflow cross-section in relation to the surrounding environment.
Advantageous further developments of the invention are described in the following description.
The invention is based on the fact that with the depositing of the fibers onto the deposit belt moving transversally in relation to the forming outlet, a reorientation of the fibers must occur, from a vertical movement to a horizontal movement defined by the deposit belt. Thus, it has been determined that by means of a controlled supplying of a secondary air flow to the entry end, the reorientation, and thereby the depositing, of the fibers can be influenced in a positive manner thereby, such that an evening out of the depositing of the fibers occurs. In this respect, the entry opening having an adjustable inflow cross-section offers the advantage of enabling a supplying of a secondary air flow from the surrounding environment adjusted to the type of fiber and the size of the fibers into the forming zone. By means of the secondary air flow entering at the entry end, the fibers are advantageously accelerated in the direction of movement of the deposit belt, which is beneficial for the reorientation. In addition, it is obtained thereby that the fibers protruding from the forming outlet in the region of the entry end, in relation to the fibers protruding in the region of the output end within the empty space, pass through open areas of different lengths. As a result, the fibers in the entry region receive, in particular, a longer time period within the open area for the reorientation to the direction of movement of the deposit belt. These effects have a particularly positive influence on the uniform depositing, and thereby on a fibrous web generated in a uniform manner.
In order to enable an individual adjustment to the secondary air flow, the device according to the invention includes sealing means at the entry end formed by a moveable sealing plate at the entry end, which determines the inflow cross-section of the feed opening with its respective adjustment in relation to the deposit belt. In this manner it is possible to adjust the inflow cross-section of the feed opening in a continuous manner.
For this, it is proposed that the sealing plate be retained at a pivotal axis, which extends transversally, spaced from the deposit belt. As a result, it is possible to adjust the feed opening ranging from a closed state to a state in which it is open to the maximum possible extent.
In order to obtain the least possible secondary air flow entering from the surrounding environment and according to an advantageous further development of the invention, the sealing means at the output end is formed of a sealing roller, which can be driven at a circumferential speed. As a result, the sealing roller can be supported with a minimal contact to the surface of the deposited fibrous web. For this, the circumferential speed of the sealing roller is preferably equal to a belt speed of the deposit belt. As a result, it is possible to prevent undesired relative speed differences between the sealing roller and the fibrous web.
In order to ensure that the sealing roller in relation to the deposit belt includes an optimal setting for the respective fibrous web, the sealing roller is designed such that it can be adjusted in terms of height in relation to the deposit belt. As a result it is possible to obtain an optimal sealing of the forming zone at the outlet end of the deposit belt for any thickness of the fibrous web.
In order for the height of the gap adjusted between the sealing roller and the deposit belt to remain constant during operation, it is furthermore proposed that a cleaning agent be associated with the sealing roller, by means of which the outer surface of the sealing roller can be cleaned. As a result, adhesion of individual fiber particles on the circumference of the sealing roller can be prevented. Cleaning agents of this type can be obtained, for example, directly, by means of contact with a scraper, or without contact, by means of a vacuum.
The longitudinal surfaces of the forming zone are advantageously shielded from the surrounding environment by means of sealing walls, wherein the sealing walls at the entry end include a wall end extending beyond the forming zone. As a result, the edge turbulence effect generated by the entry of the secondary air flow can be kept out of the forming zone. Alternatively, the wall ends of the sealing wall may be designed such that they can be extended at the longitudinal surfaces, such that, depending on the size of the inflow cross-section of the feed opening, sealing walls adjusted to different lengths can be obtained.
In order to be able to obtain different adjustments to the width of the forming zone, it is furthermore proposed that the sealing walls are designed such that they can be adjusted in order to adjust for a deposit width transversal to the deposit belt.
A further particularly advantageous development of the invention provides that the suction device includes numerous air guidance means, by means of which a suction profile oriented to the plane of the wall can be adjusted. As a result, additional deposit effects and uniformity in the depositing of the fibers to the fibrous web can be generated.
Likewise, in particular, the suctioned in secondary airflow can be modified thereby.
In order to be able to deposit the greatest variety of types and sizes of fibers to the fibrous web, it is furthermore proposed that the forming head is designed such that it can be adjusted in terms of height in relation to the deposit belt.
The device according to the invention is thus suited for the depositing of any type of fibers and fiber mixtures. As such, it is possible to deposit synthetic or natural fibers, or mixtures of synthetic and natural fibers onto fibrous layers. As a result of the high degree of uniformity in the fibrous layer that is generated, it is also possible to advantageously integrate preferably very fine particles into the mixture, in the form of a powder, for example.
BRIEF DESCRIPTION OF THE DRAWINGS
The device according to the invention shall be explained in greater detail in the following, by means of a few embodiment examples in reference to the attached figures.
FIG. 1 shows schematically, a cross-section view of a first embodiment example of the device according to the invention.
FIG. 2 shows schematically, a top view of the embodiment example from FIG. 1 , without the forming head.
FIG. 3 shows schematically, a top view of another embodiment example of the device according to the invention, without the forming head.
DESCRIPTION
A first embodiment of the device according to the invention is shown schematically in FIGS. 1 and 2 . In FIG. 1 , the embodiment is schematically depicted in a cross-section view, and in FIG. 2 a top view is shown, without a forming head. To the extent that no express reference is made to one of the figures, the following description applies to both figures.
The device of the first embodiment includes a mixing chamber 1 , which is connected via a fiber feed 2 to a fiber supply, which is not shown here. The fiber feed 2 can contain one or more connections for supplying one or more fibers or fiber mixtures to the mixing chamber 1 by means of an air flow. The mixing chamber 1 is connected at a bottom surface to a forming head 3 . The forming head 3 includes numerous means, not shown here in greater detail, for distributing the fibers or fiber mixtures, and evenly discharging said fibers, as a fiber flow, at the forming outlet 4 formed on the bottom surface. The forming outlet 4 preferably includes a sieve plate 5 or a taut screening web. Accordingly, the distribution occurs within the forming head 3 , preferably via numerous powered blades, such as is known, for example, from WO 2004/106604.
The forming head 3 is disposed above a deposit belt 8 such that the forming outlet 4 extends above and parallel to the deposit belt 8 . The substantially horizontal deposit belt 8 is designed such that it is gas permeable, and is continuously guided via a plurality of guide rollers 9 in a material supply device, indicated by a double arrow. To this extent, the deposit belt 8 runs continuously through a forming zone 6 from an entry end 10 to an outlet end 11 . Thus, the fibers are deposited to form a fibrous layer 23 in the forming zone 6 on the surface of the deposit belt 8 .
The forming outlet 4 of the forming head 3 is designed to be rectangular in this case, such that the forming zone 6 above the deposit belt 8 is also rectangular. An empty space 7 of the forming zone 6 , formed between the forming outlet 4 and the deposit belt 8 , is shielded from the surrounding environment by means of a plurality of sealing means 12 . 1 - 12 . 4 . The sealing means 12 . 1 disposed at the entry end 10 form an open feed opening 14 opposite the deposit belt 8 , so that the empty space 7 of the forming zone 6 is directly connected to the surrounding environment. The feed opening 14 forms an open inflow cross-section to enable an inflow of a secondary air flow from the surrounding environment. In order to adjust to a specific inflow cross-section, the sealing means 12 . 1 in this embodiment includes a movable sealing plate 18 . Consequently, a specific inflow cross-section of the feed opening 14 is set by respectively adjusting the sealing plate 18 in relation to the deposit belt 8 . For this purpose, the sealing plate 18 may be mounted on a pivotal axis 19 , which extends transversally to the deposit belt 8 . The sealing plate 18 can be adjusted in an analog manner over the pivotal axis 19 between a closed setting and a maximum open setting. The maximum opening of the sealing plate 18 is illustrated in FIG. 1 with a broken line.
The empty space 7 in the forming zone 6 is shielded at the outlet end 11 against the surrounding environment by means of a sealing means 12 . 2 . The sealing means 12 . 2 is designed as a powered sealing roller 13 . The sealing roller 13 is mounted in a roller rack 24 such that it can be adjusted in terms of height. Thus, it is possible to adjust the height of the sealing roller in relation to the deposit belt 8 in an analog manner, in order to obtain a shielding adjusted to the thickness of the fibrous layer. The sealing roller 13 is powered by means of a roller motor 25 , which is coupled to a control device 26 . A sensor 27 is associated with the control device 26 , which detects the respective belt speed of the deposit belt 8 . To this extent, it is possible to operate the sealing roller 13 at a circumferential speed that is the same as the belt speed of the deposit belt 8 . As a result, it is possible to guide the surface of the sealing roller 13 and the surface of the fibrous layer 23 at the same speed, without any relative motion with respect to one another.
In order to maintain a set clearance between the deposit belt 8 and the sealing roller 13 , a cleaning agent 28 is associated with the sealing roller 13 . The cleaning agent 28 in this embodiment is designed as a suction device for continuously suctioning off fiber particles adhering to the surface of the sealing roller 13 .
The empty space 7 of the forming zone 6 is shielded at both longitudinal surfaces from the surrounding environment by means of the sealing means 12 . 3 and 12 . 4 , formed between two parallel sealing walls 15 . 1 and 15 . 2 . The sealing walls 15 . 1 and 15 . 2 extend thereby between an upper surface of the deposit belt 8 and a lower surface of the forming head 3 . The sealing walls 15 . 1 and 15 . 2 each form a clearance 30 in relation to the sealing roller 13 . The opposing wall ends 29 . 1 and 29 . 2 are designed to be longer, and extend beyond the forming zone 6 . Thus, it is possible to advantageously displace the occurrence of edge turbulences, which arise with the entry of a secondary air flow from the surrounding environment, preferably to an uncritical region lying outside of the forming zone 6 . For the purpose of adjusting a deposit width of the forming zone 6 , the sealing walls 15 . 1 and 15 . 2 are designed such that they can be adjusted transversally to the deposit belt 8 . For this, an exchange of the sealing means 12 . 1 occurs, in order to form a feed opening adjusted to the respective deposit width.
A suction device 16 is disposed beneath the deposit belt 8 , connected to a vacuum source, not shown here, by means of a suction channel 17 . The suction device 16 forms a vacuum chamber 31 beneath the deposit belt 8 , in which a plurality of air guidance means 21 are associated with the bottom surface of the deposit belt 8 . In this embodiment, the air guidance means 21 are formed by adjustable damper flaps, which can be adjusted independently of one another, such that a suction profile can be adjusted over the length of the forming zone 6 . Thus, it is possible, particularly by means of the air guidance means 21 associated with the entry end 10 , to influence the secondary air flow entering through the feed opening 14 .
In the embodiment of the device according to the invention depicted in FIGS. 1 and 2 , a mixture of synthetic fibers, for example, is fed to the mixing chamber together with a powder via an air flow. Static or dynamic means can be formed within the mixing chamber 1 , which execute a pre-mixing of the fibers. Subsequently, the mixture of fibers and powder is fed via the air flow into the forming head 3 . A distribution of the fiber-powder mixture occurs within the forming head 3 via the distribution means, which is subsequently fed to the empty space 7 as a fiber flow via the forming outlet 4 . A continuously acting suction flow is generated via the suction device 16 within the forming zone 6 , which, on one hand, receives fibers entering the empty space 7 , and on the other hand, causes a secondary air flow entering at the feed end 10 from the surrounding environment, which flows through the feed opening 14 . With the guidance of the fibers within the empty space 7 , the fibers of the fiber flow are accelerated in the running direction of the deposit belt 8 in the region of the entry end 10 , with the effect that the fibers pass through a longer open path before being deposited on the deposit belt 8 , and already are pre-oriented in a manner favorable to the reorientation from the vertical movement to a horizontal movement. In contrast, the fibers are not substantially accelerated at the opposite outlet end 11 , such that they pass through a shorter open path in relation to the fibers at the feed end 10 . Thus, it is possible for the fibers to be deposited in the direction of the material flow with a slight pre-orientation by means of the effect of a secondary air flow at the feed end. This has been shown to be particularly advantageous in the formation, specifically, of a uniform fibrous layer 23 .
At the outlet end 11 opposite of the forming head 3 , suctioning in of a secondary air is prevented by means of the sealing roller 13 . In this respect, only the effect of the secondary air allowed to enter via the feed opening 14 remains in the forming zone 6 , which can be implemented in a targeted manner in order to improve the depositing of the fibers.
The device according to the invention is particularly suited for obtaining a high degree of uniformity in the generation of fibrous layers, formed by a plurality of individual, finite fiber sections. For this, synthetic or natural fibers, or a mixture of synthetic and natural fibers can be deposited.
Depending on the size and type of the fibers, the spacing between the forming outlet 4 and the deposit belt 8 can be advantageously altered by designing the forming head 3 such that it can be adjusted in terms of its height. For the height adjustment, two actuators 20 . 1 and 20 . 2 , for example, may be used, each of which engage with a supporting arm 22 . 1 and 22 . 2 , which are connected in a permanent manner to the forming head 3 . In FIG. 1 , the actuators 20 . 1 and 20 . 2 as well as the support arms 22 . 1 and 22 . 2 are depicted by means of a broken line. It is thus possible to expand the sealing of the forming zone 6 in the case of greater spacings between the forming outlet 4 and the deposit belt 8 in an advantageous manner by means of additional sealing walls on all sides of the forming zone 6 .
In order to optimize the forming zone, in particular with the entry of the secondary air flow at the entry end, another embodiment example of the device according to the invention is shown in FIG. 3 , in a top view of the forming zone 6 . This embodiment is substantially identical to the embodiment example according to FIG. 1 and FIG. 2 , such that in the following only the differences shall be explained, and otherwise, reference is made to the aforementioned description. As such, this embodiment is identical in the cross-section view to the embodiment example according to FIG. 1 .
With the embodiment depicted in FIG. 3 the sealing means 12 . 3 and 12 . 4 on the longitudinal surfaces of the forming zone 6 are likewise formed by sealing walls 15 . 1 and 15 . 2 . The sealing walls 15 . 1 and 15 . 2 each include adjustable wall ends 29 . 1 and 29 . 2 opposite the entry end 10 . The wall ends 29 . 1 and 29 . 2 can be adjusted in an analog manner in relation to the respective adjusted feed opening 14 , such that air turbulences of the secondary air flow can be advantageously prevented upon entry into the forming zone 6 .
The sealing means for shielding the forming zone and for forming a feed opening depicted in the embodiment examples according to FIGS. 1-3 are exemplary. Fundamentally, the sealing rollers at the outlet end, for example, could be formed by means of a plate with an elastic sealing lip. Likewise, the feed opening at the entry end could simply be formed by means of damper flaps or blade shaped sealing means. Advantageously, the device according to the invention provides a defined or adjustable secondary air flow generated at the entry end.
Reference Symbol List
1
mixing chamber
2
fiber feed
3
forming head
4
forming outlet
5
sieve plate
6
forming zone
7
empty space
8
deposit belt
9
guide rollers
10
entry end
11
outlet end
12.1, 12.2, 12.3, 12.4
sealing means
13
sealing roller
14
feed opening
15.1, 15.2
sealing wall
16
suction device
17
suction channel
18
sealing plate
19
pivotal axis
20.1, 20.2
actuator
21
air guidance means
22.1, 22.2
support arm
23
fibrous layer
24
roller rack
25
roller motor
26
control device
27
sensor
28
cleaning agent
29.1, 29.2
wall ends
30
clearance
31
vacuum chamber
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A device for dry-forming a fibrous web, in which a plurality of fibers or fiber mixtures is supplied to a forming head by means of an air flow, is described. The forming head includes a forming outlet arranged above a gas-permeable deposit belt. The fibers deposited on the deposit belt within a forming zone are continuously conveyed out of the forming zone by the deposit belt. A clearance of the forming zone formed between the forming head and the deposit belt is shielded with respect to the surroundings by several sealing means. To obtain as uniform a composition of the fiber layer as possible when depositing the fibers, the sealing means arranged on a feed side forms an inlet opening having an adjustable inflow cross-section through which a defined secondary air flow flows from the surroundings into the clearance.
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REFERENCE TO RELATED APPLICATION
[0001] The benefit is hereby claimed of U.S. Provisional Patent Application No. 60/420,897, entitled Low-Temperature Flux for Soldering Nickel-Titanium Alloys and Other Metals With Surface Refractory Oxides, invented by Leonard Nanis, and filed on Oct. 24, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to techniques for manufacturing components comprising shape memory alloys and other metals, and more particularly to soldering techniques and flux materials used in soldering.
[0004] 2. Description of Related Art
[0005] In recent years, nickel-titanium shape memory alloys have found an increasing number of applications in medical devices where their unique properties permit the design of miniature structures for special purposes within arteries and elsewhere within the body. As described in U.S. Pat. No. 6,371,970, tiny nickel-titanium wire hoop forms may be tightly folded and then opened within an artery in order to act as the framework for a tiny net designed to capture plaque fragments dislodged from the artery wall into the blood stream during angioplasty procedures and thus prevent potential embolism.
[0006] In another type of application, described in U.S. Pat. No. 6,090,105, curved nickel-titanium memory alloy wires can be retracted within a straight trochar and, when in the body, extended to regain their pre-set curved form to act as electrodes for applying localized microwave energy to ablate tumors.
[0007] The novel flux of the present invention will add flexibility of design by permitting the joining of nickel-titanium alloys to other metal structural components of medical devices such as stainless steel.
[0008] The oxidation resistance of refractory metals may be attributed to the presence of naturally formed protective surface oxides (or oxygen containing compounds) which, when dense and adherent, shield the underlying metal from further oxidation. This quality is desirable in alloys designated for high temperature use. However, without mechanical removal or chemical dissolution by an applied liquid phase flux, the oxide skin also prevents the wetting of the refractory metal by low melting solder.
[0009] Acid-containing fluxes are frequently used to remove the oxide layer on various metals to promote wetting by low temperature (below 300° C.) solders such as conventional lead-tin mixtures, tin with 0 to 6% silver, and 80% gold-20% tin alloy.
[0010] For higher temperature joining of metals by brazing, surfaces are first cleaned of oxide by applying and heating a flux typically containing borate and fluoride salts. In brazing, the liquid flux permits molten filler metals such as copper-silver alloys to wet and flow on the surfaces of the parts being joined. In general, a problem arises when the temperature needed for proper fluxing is greater than a limiting temperature associated with preserving the mechanical properties of the metals involved.
[0011] The natural oxide formed on nickel-titanium alloys having unique shape memory or superelastic behavior (Nitinol, Elastinite) is not easily wetted by low temperature solders such as 80% gold-20% tin or 96% tin-4% silver. Accordingly, soldering to shape-memory alloys such as Nitinol presents special requirements. The melting temperature of the solder and the temperature for good fluxing action must be less than any annealing temperature previously applied to establish a desired shape for a device designed to utilize the unique memory properties of the nickel-titanium alloy. Certain acidic aqueous fluxes containing phosphoric acid satisfy the low temperature requirement but are known to cause embrittlement of the nickel-titanium alloy, presumably due to hydrogen produced by a cathodic reaction on the metal surface. Hydrogen embrittlement caused by heated phosphoric acid flux has been described by Pelton et al. (pages 395-400, Proceedings of the Second International Conference on Shape Memory and Superelastic Technologies, March 1997; published by SMST, Santa Clara Calif., ISBN 0-9660508-1-9).
[0012] In the present invention, the molten hydroxide eutectic is non-aqueous, so that free hydrogen ions are not available to act as a source for hydrogen embrittlement through electrochemical reaction.
[0013] Other fluxes clean Nitinol but require temperatures that can produce a loss or diminution of the desirable mechanical properties of the shape memory alloy. T. Hall, in U.S. Pat. No. 5,242,759 and U.S. Pat. No. 5,354,623, teaches a flux for soldering nickel-titanium alloys which is an aqueous paste mixture of organic amines, hydrofluoric or hydrochloric acid and various chloride salts wherein the mixture only becomes active at temperatures greater than 246° C. (475° F.).
[0014] Nanis et al. (U.S. Pat. No. 5,695,111) find that the cleaning of oxide from the surface of nickel-titanium alloy can be accomplished at temperatures as low as 170° C., the melting temperature of a sodium hydroxide-potassium hydroxide eutectic mixture. Nanis et al. teach a two-layer method in which a layer of liquid hydroxide flux is maintained over a layer of liquid 80% gold-20% tin solder alloy, which melts at 185° C. A part is first immersed in the flux layer for a specified time for oxide removal and is then more deeply immersed so as to make contact with the underlying layer of liquid gold-tin alloy solder. The gold-tin solder wets and coats the freshly cleaned nickel-titanium. After the part is withdrawn from the two-layer array, the solidified gold-tin solder layer provides an intermediary surface which is then wettable by other solder compositions, such as 95% tin-5% silver, for assembly of the nickel-titanium part in a device.
[0015] Another method for promoting adhesion of tin-silver solder is to electroplate the nickel-titanium surface with a metal known to be wettable by liquid solder. It is desirable that such plated metals have either no oxide layer of their own, or can be cleaned with conventional flux during soldering. Electroplated gold, nickel and other plated metals serve the purpose. However, as experienced in most plating systems, oxide removal and preliminary cleaning of the object to be plated is accomplished by a series of immersions in various etchants such as mixtures containing hydrofluoric and other acids. Hydrogen embrittlement is possible from such etch treatments.
[0016] Good plating practice requires that the part be transferred quickly into the plating tank after cleaning and rinsing steps in order to prevent re-oxidation. Thus, the burden falls on the plater to obtain good adhesion of the plated layer to the nickel-titanium substrate. The extra step of plating a solder-wettable layer adds to the expense and complexity of manufacture, particularly for small medical device parts which require special fixturing to assure good current distribution and electrical contact during plating.
[0017] Problems with the plating of nickel on nickel-titanium alloys have also been noted by P. Hall (“Methods of Promoting Solder Wetting on Nitinol”, page 126, Proceedings of the Second International Conference on Shape Memory and Superelastic Technologies, March 1997; published by SMST, Santa Clara Calif. ISBN 0-9660508-1-9).
SUMMARY OF THE INVENTION
[0018] Oxides which form naturally on certain useful metals can be removed by a liquid flux to promote wetting of the underlying metal when molten solder is applied. The flux of this invention serves a threefold purpose: First, the metal oxide is dissolved by the molten hydroxide salt mixture at relatively low temperatures such as 230° C. Immersion of the refractory metal or alloy part in the molten salt may be brief, on the order of a minute or even less, for dissolution of the oxide skin on, for example, a Nitinol wire shape.
[0019] Second, upon withdrawing the metal part from the molten hydroxide salt, a layer of adhering salt rapidly freezes which then retards the oxygen of the atmosphere from re-oxidizing the clean metal surface.
[0020] Third, the adhering salt provides a source of flux to keep the metal surface clean during a subsequent soldering operation so that added solder may wet the metal surface and flow readily.
[0021] The melting temperature of the flux is below the range of temperatures which may adversely affect the mechanical properties of Nitinol. A previously thermally configured Nitinol part may thus be cleaned of oxide in the present flux, then protected from re-oxidation by adhering flux and then soldered in its final assembly position. Any surplus adhering remelted hydroxide flux may be easily washed off in water.
[0022] Alternately, the present two-step flux-tin method may be used to pre-coat or “tin” a part with solder. After washing off any residual adhering hydroxide flux, the pre-tinned part may then be attached to other metallic components by conventional soldering means. In the present invention, a thin film of liquid hydroxide flux adheres when the cleaned part is lifted from the molten hydroxide flux. The flux film rapidly solidifies and then serves both to retard re-oxidation of the metal and also to provide a flux source for subsequent solder application. A first flux immersion may be used to clean the Nitinol surface in preparation for adding a coating of tin metal by the method of electrolytic displacement in which the said cleaned Nitinol is immersed in a second molten hydroxide which also contains tin ions contributed from dissolved tin-bearing compounds such as tin oxide.
[0023] The two-layer method of Nanis et al. (U.S. Pat. No. 5,695,111) necessarily requires that flux cleaning and gold-tin solder coating be accomplished in a single container of test tube shape, positioned vertically as in an electrically heated tube furnace. Such an arrangement is not necessary in the present invention.
[0024] Whereas U.S. Pat. No. 5,695,111 mentions a process in which a Nitinol part is immersed in a multilayered bath, in a procedure involving immersing for a certain time in an upper hydroxide melt layer and then lowering directly into an underlying molten gold-tin layer (see column 9, lines 8-25), the present invention decouples cleaning from solder coating or from subsequent steps such as tinning by electrolytic displacement. Cleaning of the Nitinol surface in hydroxide flux is physically separated from contact of the cleaned surface with solder. The solder may be held in a separate container or may be applied as in conventional soldering with a soldering iron. Likewise, the molten salt for electrolytic displacement tinning may be held in a separate container. Time of immersion in flux and the flux temperature may be optimized independently of parameters in the solder application step or other subsequent steps such as electrolytic displacement tinning.
[0025] The present invention offers several practical and cost-saving advantages over the single container, single temperature, two-layer method of Nanis et al. (U.S. Pat. No. 5,695,111). The separate containers for flux and solder may be of different materials, each selected for maximum corrosion resistance. For the flux, nickel or stainless steel are known to withstand attack from molten hydroxides, which can corrode glass and ceramic materials such as porcelain. A pool of molten solder may be held in a corrosion-resistant ceramic crucible shape. As mentioned, the solder can be applied from a solid wire with a conventional heat source such as a soldering iron or flame, either for part assembly or for pre-coating (“tinning”). A tall form crucible of material capable of resisting attack by both flux and solder is thus not necessary, as required for the two-layer method of Nanis et al. (U.S. Pat. No. 5,695,111). Further, a simple electrical hot plate may be used in combination with standard low-form cup-shaped crucibles for improved accessibility.
[0026] A most important cost advantage of the present invention is that, in many instances, tin-silver solder may be added directly to a Nitinol part, thus avoiding pre-coating with a layer of 80% gold-20% tin or by electroplated nickel. Nitinol parts pre-coated with an intermediary layer of 80% gold-20% tin according to U.S. Pat. No. 5,695,111 are so treated to facilitate subsequent soldering with tin-silver alloys. However, the present invention provides cleaning of Nitinol which permits direct addition of silver-tin alloy to the Nitinol surface. It will be recognized that savings accrue if there is no need for a volume of expensive 80% gold-20% tin alloy maintained as the lower molten pool in the two-layer, single temperature method of U.S. Pat. No. 5,695,111.
[0027] Another advantage of the present invention in separating flux cleaning from solder coating is that the metal container can accommodate the stresses caused by the considerable volume expansion during re-melting of the hydroxide salt. At its melting temperature of 170° C., the solid-to-liquid transition of the NaOH—KOH eutectic is accompanied by a volume expansion of about 15 percent, typical of many ionic molten salts. Ceramic containers may crack if melting is constrained by surrounding solid salt. Cracking may be avoided by careful “top-down” reheating of a previously solidified melt. A ceramic or non-reactive crucible is preferable for holding molten hydroxides containing dissolved compounds added to provide ions for electrolytic displacement tinning.
[0028] It will also be recognized by those skilled in the art of soldering that the hydroxide melts of the present invention may provide a convenient source for adding fresh flux to the tip of a heated soldering iron. For this purpose, the pre-mixed salt may be molten or may also be used in solidified form. In addition, an amount of solid hydroxide flux may be pre-positioned locally on a structure which, when heated, cleans the metal and assists wetting by liquid solder.
[0029] Other aspects and advantages of the present invention can be seen on review of the drawings, the detailed description and the claims, which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 illustrates a first step in a process according to the present invention in which a component having a refractory oxide is prepared to be dipped in a molten salt.
[0031] FIG. 2 illustrates a second step in a process according to the present invention in which the component is immersed in the molten salt.
[0032] FIG. 3 illustrates a third step in a process according to the present invention in which the component is removed from the molten salt, with a frozen adhering layer of the salt on a surface.
[0033] FIG. 4 illustrates schematically the joining of the component to another member by soldering, during which the adhering layer of salt acts as a flux.
DETAILED DESCRIPTION
[0034] A detailed description of embodiments of the present invention is provided with reference to FIGS. 1-4 .
[0035] Preparation or “pre-tinning” of Nitinol surfaces to facilitate soldering is accomplished in the present invention by dissolving surface oxides in low melting flux comprised of a eutectic mixture of hydroxide salts. The eutectic mixture of 59 weight percent potassium hydroxide (KOH) and 41 weight percent sodium hydroxide (NaOH) is effective. The KOH—NaOH eutectic mixture has a melting point less than either of its constituent hydroxides. The KOH—NaOH eutectic mixture melts at 170° C. compared with 318° C. for pure NaOH and 360° C. for pure KOH.
[0036] Another effective eutectic hydroxide mixture is comprised of 84 weight percent potassium hydroxide (KOH) and 16 weight percent lithium hydroxide (LiOH). The eutectic KOH—LiOH mixture has a melting temperature of 226° C., whereas pure LiOH melts at 471° C. and pure KOH at 360° C.
[0037] The eutectic mixtures may be prepared in several ways. For example, solid sodium hydroxide may be melted first, followed by addition of a known amount of potassium hydroxide. Alternately, dry pellets of each pure hydroxide may be mixed together mechanically and slowly heated to above the eutectic temperature. Liquification initiates at points of contact between hydroxide constituents as solid state diffusion creates a zone of eutectic composition. Porcelain, nickel or stainless steel crucibles may be used to contain the liquid flux. The crucible may be conveniently heated on a conventional laboratory electrical hot-plate.
[0038] Oxide cleaning action in the molten sodium-potassium hydroxide flux begins at temperatures greater than the 170° C. eutectic. A preferred method is to immerse Nitinol for one minute or less in a molten KOH—NaOH eutectic mixture maintained in the range of 230° C. to 280° C. At 280 C., there is no degradation of the mechanical properties of the nickel-titanium alloy.
[0039] FIG. 1 represents a Nitinol nickel-titanium metal wire ( 11 ) with its initial natural oxide layer ( 12 ), poised above the molten hydroxide eutectic flux ( 13 ). Although said oxide layers are generally thin, measuring on the order of 10 to 1000 Angstroms, the thickness of the initial oxide layer shown in FIG. 1 is not drawn to scale, being exaggerated for the sake of clarity.
[0040] FIG. 2 depicts Nitinol wire ( 11 ) after an end section ( 14 ) has been immersed in molten hydroxide eutectic flux ( 13 ) for a few minutes. The submerged Nitinol metal section ( 14 ) now has a clean surface since oxide layer ( 12 ) has dissolved into the molten hydroxide eutectic flux ( 13 ).
[0041] Upon removal of nickel-titanium alloy wire ( 11 ) with cleaned section ( 14 ) from the molten hydroxide eutectic flux ( 13 ), the adhering hydroxide layer ( 15 ) freezes rapidly, as indicated in FIG. 3 . The frozen adhering hydroxide eutectic layer ( 15 ) acts to limit access of atmospheric oxygen to the cleaned region ( 14 ) and thus helps to retard re-oxidation. Said cleaned region ( 14 ) is wettable by liquid solder which may be applied for pre-tinning the surface ( 14 ) in preparation for subsequent soldering operations. When wire ( 11 ) with its cleaned section ( 14 ) is reheated, the adhering solidified hydroxide flux layer ( 15 ) remelts and serves to keep wire section ( 14 ) free of oxide, thus permitting added solder to wet the metal surface either for pre-tinning or for final assembly soldering. Solidified layer ( 15 ) also protects the Nitinol surface in transit to a subsequent step such as a second melt containing tin ions for the purpose of electrolytic displacement tinning. Adhering layer ( 15 ) remelts readily into the second melt of similar composition.
[0042] Immersion times ranging from a few seconds to about three minutes are effective in removing sufficient oxide from the nickel-titanium alloy to permit full or at least partial coverage by tin-based solder when the chilled eutectic KOH—NaOH layer ( 15 ) is reheated to serve as a solder flux. The shape and volume of the molten salt containing crucible and the positioning of the part may be selected so that wires and small shapes may be cleaned and tinned completely or only in a specified region. Parts may be stored in a dessicator to prevent moisture pick-up by the solid salt while awaiting conventional soldering operations. FIG. 4 illustrates a final step in manufacturing a device using the soldering technique just described, in which a member ( 16 ) is joined to component ( 14 ), by application of solder ( 17 ), where the frozen adhering flux is reheated and acts as a flux during application of the solder ( 17 ).
[0043] The 170° C. melt temperature of the KOH—NaOH eutectic mixture is well below the 232° C. melting temperature of pure tin and the 221° C. melt temperature of a typical tin-silver solder with up to 5 weight percent silver. When used as a frozen layer and flux source during soldering, the remelted salt continues to clean the surface by dissolving any oxide that may tend to reform. When soldering is complete, any cooled hydroxide salt may be removed by washing the joined part in warm water. The rinse water will become alkaline but may be readily neutralized with a mineral acid such as hydrochloric acid. The neutralized rinse water is then a harmless salt solution, non-toxic and non-corrosive and may thus be safely disposed of in a sanitary waste line.
Figure of Merit for Measuring Solder Coverage on Nitinol
[0044] For quantifying the degree of solder wetting and coating on Nitinol for our examples, I use a figure-of-merit obtained from the energy dispersive X-ray spectrum of our treated surfaces. Coverage of solder on Nitinol may be represented as the ratio of energy dispersive X-ray (EDX) spectrum peak height for tin in the solder to the sum of said peak height for tin plus the peak height for titanium in Nitinol. Background energy in the EDX scan of intensity versus X-ray energy should be subtracted from the peak heights, designated as Sn and Ti, for the ratio
Sn/(Sn+Ti).
[0045] Scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX) is a well-known method for element analysis of regions on or close to a surface. Our SEM is a Hitachi Corp. S-2400 outfitted with an EDAX Corp. DX4 energy dispersive X-ray detection system.
[0046] In EDX mode, the electron beam of the SEM hits the sample and produces X-rays which have energies characteristic of the elements present in the sample. X-rays are produced within a small volume of the sample so that the detected emerging X-ray energies represent an average composition of the surface and of material close to the surface. Typically, an SEM electron beam energy of 10 kilovolts will activate X-rays from material to a depth of about 1500 to 3000 Angstrom.
[0047] Although the entire integrated EDX spectrum plot of intensity of emitted X-rays versus X-ray energy may be analyzed for a quantitative assay of elements in the sample depth, the peak heights (conveniently measured with a millimeter scale) offer a less rigorous but conveniently measured indicator of the amount of each element present in the activated sample volume.
[0048] For Nitinol covered by tin-silver solder, the heights of X-ray intensity peaks (above the spectrum background) for the main emitted energies for tin (L-alpha at 3.41 keV) and for titanium (K-alpha at 4.51 keV) are suitably used. The Sn/(Sn+Ti) ratio ranges from 0 to 1.
[0049] The depth and shape of the X-ray-producing volume of material energized by the incoming SEM electron beam depends on a complex interplay of several factors such as initial beam energy, X-ray absorption cross section of target components and scattering of electrons within the volume. A detailed discussion of electron beam-specimen interactions that affect sampling depth may be found in Chapter 3 of “Scanning Electron Microscopy and X-Ray Microanalysis”, Goldstein, Newbury, Echlin, Joy, Fiori and Lifshin, Plenum Press, 1981, ISBN 0-306-40768-X.
[0050] From a simplified viewpoint sufficient to define a figure of merit for the results of my invention, it is helpful to consider that if Nitinol is completely covered by a sufficiently thick layer of solder, i.e. approximately 10,000 Angstrom deep, the energy of the incoming electron beam of the SEM and of emerging X-rays produced within the solder sampling depth will be attenuated so that no underlying Nitinol will be activated to contribute X-ray energies characteristic of titanium or of nickel. The EDX spectrum will consist only of lines for tin (and silver). For a thick layer of solder and the absence of a titanium contribution to the EDX spectrum, the Sn/(Sn+Ti) ratio will be equal to unity.
[0051] When solder uniformly coats the underlying Nitinol, the Sn/(Sn+Ti) ratio is a relative measure of solder thickness. For a uniform but very thin layer of solder, the Sn/(Sn+Ti) ratio will trend to zero since there will be a greater contribution to the X-rays activated from the comparatively large amount of titanium in the underlying Nitinol. The Sn/(Sn+Ti) ratio is not a direct measure of solder thickness but does provide a means to gauge the uniformity of coverage by obtaining the EDX spectrum from adjacent regions on the surface. Partial coverage of a poorly wetted surface can readily be detected in the SEM image. Also, the Sn/(Sn+Ti) figure of merit will be zero for unwetted areas and unity for attached but unspread, relatively thick patches of solder.
EXAMPLE 1
[0052] In my invention, as an example of decoupling the oxide cleaning step from the solder coating step, Nitinol pre-cleaned by immersion in hydroxide flux at one specified temperature may be later brought into contact with a liquid solder pool at a different temperature. The adhering layer of flux which cools on the Nitinol part as it is withdrawn from the cleaning flux then remelts as it contacts liquid solder held in a separate container.
[0053] Table 1 lists representative results of such two-step treatments with Nitinol and a cleaning flux of eutectic mixture of 41 weight percent sodium hydroxide and 59 weight percent potassium hydroxide, 170° C. melting temperature. The liquid solder pool in the second container was nominally 3.5 weight percent silver, 96.5 weight percent tin (“Stay-Brite”, J.W. Harris Co., Inc., Mason, Ohio). Pure tin was also used, as noted in Table 1. Nitinol was in the form of wire ranging from 0.005 to 0.015 inch diameter, of nominal composition 55 weight percent nickel, 45 weight percent titanium, supplied by Small Parts, Inc., Miami Lakes, Fla. For convenience, porcelain crucibles were used to contain both cleaning flux and also the solder pool. Dross was mechanically scraped from the solder pool surface before immersing flux-cleaned Nitinol. Temperatures were measured with a chromel-alumel thermocouple. The only pre-treatment of parts was degreasing with isopropyl alcohol.
TABLE 1 Flux Cleaning and Solder Coating Nitinol, KOH-NaOH eutectic flux, 96.5 Sn-3.5 Ag solder Flux-Cleaning Solder-Dip time, Storage time, EDX temp., C. sec. Time min. temp., C. sec Sn/(Sn + Ti) — — — 292 30 0.0, 0.98 (not wet) 245 3 — 262 30 0.05, 0.06 (not wet) 236 30 — 260 30 0.12, 0.08, 0.09, 0.10 226 30 — 292 30 0.65 229 60 — 292 30 0.72 234 60 10 290 30 0.68, 0.42 236 60 30 292 30 0.47, 0.88, 0.98 240 60 — 280 60 0.84, 0.80, 0.78 (tin) 240 180 — 287 90 0.77 (tin) 263 180 — 287 90 0.76, 0.78, 0.74 253 300 — 277 30 0.34, 0.32, 0.39, 0.45
[0054] Most of the Nitinol parts were immersed in the solder pool immediately after flux cleaning. As indicated in Table 1, a few parts were stored for several minutes in air at room temperature. Good coverage by solder was obtained for flux cleaning times of at least 30 seconds. The individual values of Sn/(Sn+Ti) ratio figure of merit in Table 1 are from separate EDX spectra obtained from nearby locations on the solder-coated Nitinol surface. The Nitinol part that received no flux cleaning had Sn/(Sn+Ti) ratios of 0.0 and 0.98 after immersion in the solder pool for 30 seconds at 292° C. The ratio 0.98 is from an isolated patch of solder that adhered to the Nitinol but whose boundaries did not exhibit the small contact angle characteristic of good wetting. From the data for 30 second flux immersion, a solder temperature of 292° C. gave a thicker solder coating compared with solder at 260° C. Good coatings were also obtained for flux-dipped parts stored for up to 30 minutes in air. It will be recognized by those skilled in the art of soldering that other combinations of times and temperatures for both flux immersion and solder immersion may be varied in order to optimize the solder coating for a particular application. The results shown in Table 1 indicate that tin-silver solder may be directly applied to Nitinol without the need of an intermediary layer such as electroplated nickel or gold-tin alloy added by the two-layer method described by Nanis et al. U.S. Pat. No. 5,695,111.
EXAMPLE 2
[0055] Flux cleaning of Nitinol followed by contact with a solder pool was also performed with a low melting KOH—LiOH eutectic mixture comprised of 16 weight percent lithium hydroxide and 84 weight percent potassium hydroxide, with a melt temperature of 226° C. Representative results are shown in Table 2. The procedure was the same as for Example 1.
TABLE 2 Flux Cleaning and Solder Coating Nitinol, LiOH-KOH eutectic, 96.5Sn-3.5Ag solder Flux-Cleaning Solder-Dip time, Storage time, EDX temp., C. sec. Time min. temp., C. sec Sn/(Sn + Ti) 246 6 — 287 30 0.47, 0.70, 1.0, 0.76 235 30 — 287 30 0.57, 0.54 235 60 — 287 30 0.63, 0.57 248 60 10 285 30 0.33, 0.46, 0.53, 1.0
[0056] The LiOH—KOH flux cleans effectively even close to the eutectic melting temperature of 226° C. and in general, offers a slight improvement over the NaOH—KOH melt. It will be obvious to those skilled in the art of fluxes and molten salts that ternary mixtures comprised of NaOH—KOH—LiOH may be formulated which provide improved rapid cleaning of Nitinol at temperatures below those reported in Examples 1 and 2. Further, the pure hydroxide salts may also be used for flux cleaning, provided their higher melting temperatures do not degrade the mechanical properties of Nitinol or other metals being so cleaned.
[0057] The results shown in Table 2 also indicate that the fluxes of my invention permit tin-silver solder to be directly applied to Nitinol without the use of an intermediary layer.
EXAMPLE 3
[0058] The hydroxide flux of my invention may also be used for conventional soldering in which a part is heated, fluxed and then solder applied to form a bond between metal parts. Example 3 concerns pre-coated NaOH—KOH eutectic as a flux for conventional soldering with an applied heat source such as a soldering iron.
[0059] A solid flux coating was obtained on Nitinol wires by briefly immersing the Nitinol piece in the molten hydroxide eutectic described in Example 1. Adhering flux solidified upon removal from the melt and was remelted when solder was added to the flux-coated piece. A silver-tin alloy solder, 97.5 weight percent tin, 2.5 weight percent silver, was fed to the heated work piece in the form of solid wire.
[0060] Heat was provided by a programmable electric solder iron (Weller Model WSD80), set to a predetermined temperature of 428° C. (803′ F.). The Nitinol wires, coated with solidified flux, were manually held in contact with the tip of the solder iron as solder in wire form was fed onto the heated tip and on to the Nitinol. Coverage of solder on said coated Nitinol was evaluated by examining SEM images and by determining the EDX spectrum for use with the peak height ratio Sn/(Sn+Ti), as described in Examples 1 and 2. Results shown in Table 3 indicate good coverage is obtained with Nitinol pre-coated with NaOH—KOH eutectic when used with a conventional soldering iron as the heat source. Immersion of the Nitinol in molten NaOH—KOH flux cleans the surface. The adhering frozen flux protects the clean surface from oxidation and, as it remelts in the soldering procedure, continues to keep the surface clean while solder wets and spreads on the Nitinol.
TABLE 3 Soldering on Flux Cleaned and Coated Nitinol NaOH-KOH flux, 97.5Sn—2.5Ag solder Electric soldering iron, 428 C. Nitinol Flux Immersion wire diameter inch Temp., C. Time, min. EDX Sn/(Sn + Ti) 0.005 260 1.0 0.43, 0.51, 0.30, 0.81 0.013 250 1.0 0.18, 0.49 0.013 250 4.0 0.58, 0.31, 0.70
EXAMPLE 4
[0061] The flux of my invention is not limited to Nitinol but cleans other metals in preparation for soldering and tinning. Stainless steel is of interest because it is frequently used in various forms for medical devices.
[0062] Representative times and temperatures for flux and solder immersion of type 316L stainless tubing are shown in Table 4. In the figure-of-merit EDX intensity ratio for solder coverage on 316L stainless steel, the chromium K-alpha line at 5.42 keV is conveniently located in the X-ray spectrum for comparison with the main tin line (L-alpha) at 3.41 keV. Type 316L stainless steel was annealed coronary tubing, 0.062 inch OD, 0.051 inch ID, Superior Tube Corp. Tubing was cleaned before use by wiping with isopropyl alcohol. Eutectic hydroxide flux mixtures were as described in Examples 1 and 2.
[0063] There was very little wetting by solder for 316 L tubing that was not flux cleaned. Solder coverage was in a few isolated patches occupying only 5 percent of the surface. The first entry in Table 4 thus serves as a reference surface. All other time-temperature-hydroxide combinations produced excellent coverage. In general, flux cleaning is rapid, requiring only a few seconds in the temperature range 240° to 250° C.
TABLE 4 Flux Cleaning and Solder Coating 316L Stainless Steel, Hydroxide eutectic fluxes, 96.5Sn-3.5Ag solder Flux-Cleaning Solder-Dip Temp., Ttime,. Temp., Ttime, Type C. sec C. sec EDX Sn/(Sn + Cr) NaOH-KOH — — 290 30 0.0, 1.0(poor wetting) ″ 240 3 240 30 1.0 ″ 238 6 268 30 1.0 ″ 245 30 268 30 1.0 ″ 248 6 285 30 0.85, 0.99 ″ 248 30 268 30 1.0, 0.92, 0.96 KOH-LiOH 248 6 285 30 0.85, 0.98 ″ 248 30 285 30 0.92, 0.96, 1.0
EXAMPLE 5
[0064] The hydroxide flux of my invention may be used for pre-cleaning Nitinol in preparation for an electrolytic displacement reaction to deposit tin metal on the Nitinol surface. The displacement reaction takes place in a second molten salt serving as a solvent electrolyte for dissolved tin ions. The displacement reaction causes a layer of tin metal to plate automatically onto the flux-cleaned Nitinol surface. Accordingly, immersion in a pool of molten tin metal is not necessary, as for Examples 1 and 2 cited above.
[0065] We have discovered that a layer of tin metal will deposit on Nitinol when the flux-cleaned Nitinol is then immersed in a second crucible containing a molten salt of similar hydroxide chemistry to which has been added tin oxide. The benefit of protection against re-oxidation of the surface is provided by the adhering frozen hydroxide as shown in FIG. 3 .
[0066] Solid tin oxide dissolves in the hydroxide molten salt and thereby provides tin in an ionic form which may then enter electrochemical reaction to deposit a layer of tin on the Nitinol. By the principles of electrochemical systems, the tin ions may be considered as participating in a so-called displacement reaction in which the tin ions are reduced to metallic tin on the surface of the Nitinol. In such displacement reactions, an electropositive metal will deposit, “displacing” an electronegative metal which then dissolves into the electrolyte; in this case, the molten hydroxide salt. The electrons which discharge and neutralize the tin ions are provided in a balanced manner from the electronegative metal as it becomes a positively charged species dissolved in the molten ionic hydroxide salt.
[0067] The exact reaction mechanism and reaction kinetics underlying the finding of our invention are not presently known. Equally, an equilibrium electromotive force scale is not known for ions dissolved in molten hydroxide salts in order to designate which metal-ion combinations are most electropositive. The order of metal-ion pairs is not necessarily the same as in the well-known electromotive force series for aqueous electrolytes. However, our invention usefully demonstrates that tin-containing ions accept electrons and are automatically reduced to tin metal on the Nitinol surface. Tin is thus the electropositive metal of the displacement reaction in the molten hydroxide solvent. Titanium in the Nitinol alloy may be the electronegative metal but this is not presently certain. Tin exists in the tetravalent state (4+) in tin oxide, with formula SnO2, and also in a divalent state (2+) in another oxide with formula SnO. Both oxides dissolve to some extent in molten hydroxide flux and each oxide is effective in supplying tin ions for a displacement type of reaction to form a tin metal layer on Nitinol.
[0068] The initial immersion in hydroxide flux, as shown in FIG. 2 , is considered to dissolve the naturally occurring oxide skin from Nitinol, thus cleaning the surface which is then better prepared to participate in the displacement reaction when immersed in the second hydroxide containing dissolved tin oxide. Some degree of metallic tin deposition can also be obtained by immersing Nitinol in only a single melt, namely the hydroxide melt with dissolved tin oxide since, in principle, the naturally occurring oxides on Nitinol dissolve in the melt acting as flux while the displacement reaction proceeds on the freshly cleaned Nitinol with the same melt also functioning as a solvent electrolyte.
[0069] As shown in Table 5, improved tin coating is obtained with pre-cleaning. Whereas the Sn/(Sn+Ti) figure of merit is an average 0.1 without pre-cleaning, improvement is obtained with a pre-cleaning flux immersion, with better results as the pre-cleaning immersion temperature is increased from 224 C. to about 270 C.
TABLE 5 Flux Cleaning and Electrolytic Displacement Tinning of Nitinol NaOH-KOH eutectic cleaning flux; NaOH-KOH-tin oxide displacement melt (10 percent by weight tin oxide added to eutectic NaOH-KOH) Flux-cleaning Displacement time, time Tin Oxide EDX temp., C. sec temp., C. sec valence Sn/(Sn + Ti) — — 261 60 4+ 0.07, 0.22, 0.13, 0.11, 0.03 224 60 236 60 4+ 0.09 224 180 236 60 4+ 0.21, 0.10, 0.24 258 30 267 180 4+ 0.23, 0.50, 0.48, 0.28 268 30 267 180 4+ 0.51 268 60 267 180 4+ 0.48, 0.14, 0.36 270 120 257 120 4+ 0.53 270 120 273 120 4+ 0.51, 0.53, 0.32, 0.34 268 180 264 180 4+ 0.31, 0.26, 0.25 224 60 239 60 2+ 0.19, 0.18, 0.13, 0.19 224 180 239 180 2+ 0.24
[0070] As noted in the caption for Table 5, melts containing either tetravalent or divalent tin oxide are prepared by adding 10 weight percent of oxide to a NaOH—KOH eutectic mixture. The actual amount which goes into solution at each temperature is not presently known. As in Tables 1-4, multiple values of the Sn/(Sn+Ti) figure of merit indicate EDX data obtained at several locations on a surface.
[0071] The method of Example 5 of pre-cleaning followed by displacement tinning provides sufficient tin on the Nitinol surface to promote wetting in a subsequent soldering step. Those familiar with electrochemical practice will recognize that the molten hydroxide electrolyte containing dissolved tin ions can serve as a conventional plating solution. Rather than relying only the displacement reaction to deposit tin metal, tin plating may be assisted by an applied voltage from a direct current power supply in a circuit in which the Nitinol is made cathodic and an anodic counter electrode is provided.
[0072] In general, according to the electrochemistry of displacement reactions, molten hydroxide salts and mixtures thereof can serve as the solvent for tin ions and also for the ions of other metals. The source of the metal ions may be dissolved oxides, as in the example of tin, or may be other types of salt compounds such as halides, providing there is solubility of said compounds in the molten hydroxide. Tin ions will also deposit as metallic tin on other relatively electronegative metals by displacement reaction. In addition, alloying elements may be co-deposited with tin, depending on their relative electronegativity and concentration of dissolved ions.
[0073] While my invention has been described in examples with specific embodiments, those skilled in the art will recognize that variations can be made with regard to details without departing from the spirit and scope of the invention. For example, low-melting eutectic hydroxide fluxes may be used to clean the oxide layer from other metals of interest for tinning or soldering. In addition, the hydroxide flux may also be applied in solid or paste form suitable for remelting. Also, it will be recognized that a partially coated surface may be improved by re-immersion of the part in molten flux, thus permitting additional cleaning of oxide and better wetting of the recleaned surface by remelted solder. Accordingly, all such variations come within the present invention.
[0074] While the present invention is disclosed by reference to the preferred embodiments and examples detailed above, it is to be understood that these examples are intended in an illustrative rather than in a limiting sense. It is contemplated that modifications and combinations will readily occur to those skilled in the art, which modifications and combinations will be within the spirit of the invention and the scope of the following claims.
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A low-temperature flux is described which dissolves the refractory oxide layer from a shape memory alloy containing both nickel and titanium, such as Nitinol, and from other metals like stainless steel. The flux is particularly useful for preparing shape memory alloy members for soldering and permits joining of such members to other members, comprising, for example, stainless steel, used in structures like medical devices. The flux is a non-aqueous molten salt formulated on eutectic mixtures of KOH (potassium hydroxide), NaOH (sodium hydroxide) and LiOH (lithium hydroxide), with melting temperatures in a range from about 170° C. to about 226° C.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to tents, and more particularly describes a portable, lightweight tent, which has, for transportation, a lightweight and compact rectangular container, which, when opened, forms an integral support-portion and covering-portion of the erected enclosure.
2. Description of the Prior Art
A lightweight and portable personal enclosure has been a useful and desirable item for the soldier, hiker, cyclist and motorist. Because of the inherent vulnerability of the fabrics often used in such enclosures, it has also been an object of the invention to integrate an enclosure such as that previously described, with a sturdy and protective container.
A knapsack tent is described and illustrated in U.S. Pat. No. 39,150 to L. Joubert. A tent in which the rectangular hinged container serves as the floor is described in U.S. Pat. No. 143,037 to J. B. Smith. However, in that case, a relatively large container, 40 inches wide and 51/2 feet long is required and, because its designation as a "floor" dictates the maximum size of the enclosure, it restricts the portability of the combination.
More recently, a sunshade awning with the awning material also comprising the outside of the container is found in U.S. Pat. No. 2,853,086 to A. J. Biagosch, but the soft material provides only limited protection.
All of the foregoing inventions have limitations either in their enormous size, or the lack of a durable and protective container which can also serve as a useful portion of the completed enclosure.
Consequently, a need exists for improvements in such portable enclosures which will result in improved protection for the fabric of the enclosure, the absence of limitation in the size of the completed tent, and the utilization of the container as an effective structural portion of the completed enclosure.
SUMMARY OF THE INVENTION
The present invention provides a portable personal enclosure to satisfy the aforementioned needs. The invention embodies a lightweight plastic container, such as fiberglass reinforced plastic or ABS plastic as a portion of the top of the enclosure.
The present invention relates to a unified personal enclosure having lightweight Dacron or nylon side panels, a collapsable or segmented single center support, corner stakes, and a hinged rectangular container which, when opened, forms the top portion of the completed enclosure, as well as providing structual support to the upper portion of each of the side panels of the completed tent. In addition, the enclosure is equipped with an openable flap for entry and exit, and the container is of sufficient size to hold all tent fabric, the segmented or telescoping center pole, as well as the ground stakes, and still presents an extremely lightweight and portable package when in its collapsed and hinged configuration.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows four separate views of the container, FIGS. 1A, 1B and 1C show the front elevation, top and side views of the container respectively, while FIG. 1D shows the container in perspective, unfolded in preparation for mounting the tent fabric.
FIG. 2 is a prospective view of the completed enclosure, as well as a side view of the segmented or telescoping center pole, with two detail drawings of the junction of the segmented or telescoping sections.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, and more particularly to FIG. 1, there is a container (1) of relatively compact size (typically, twelve to eighteen inches in length, four to six inches in width, and three to five inches in depth), which consists of two identical half sections, each comprising a five-sided box, which sections are placed together in such a fashion so that the open portion of each box is mated precisely, and one side of the mated pair is secured together with a hinging device (4). The side of the paired boxes which is disposed directly opposite the aforedescribed hinge is equipped with a latching mechanism (3). Multiple "U" shaped clips (2) are provided for holding container (1) in its open positiion.
In the preferred embodiment of the container, the tent fabric (6), the tent center pole segments or telescoping center pole (5), and the tent stakes (11), are collapsed and placed in the container (1), which is closed with latch (3).
For erection of the completed structure, the latch (3) is freed, and the container is opened fully, to permit removal of the contents. The faces of the container are fully opened as in FIG. 1D, so that the faces of the container to which the hinge flaps are attached become directly in contact. Clips (2) are inserted over the mated sides of the container to secure the container in open position, creating a more or less rigid container open on one side, and approximately square in shape.
The tent walls (6) are then attached to the (inside/outside) walls of the now unfolded container, and the fabric is secured at corner points (10) with stakes (11). A collapsable or segmented center pole (9) is then extended. The upper segment of said center support is equipped with means to permit it to be secured to the center of the unfolded container. The center pole may be either segmented, with multiple pieces (5), equipped with pin and socket juncture (14) or may be a single telescoping pole equipped with telescoping junctions (15). The extended or assembled center pole is then pushed into position inside the enclosure, resulting in a more or less pyramid-shaped personal enclosure, equipped with an entry opening (13) and closure (16).
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An integral tent and container for portable applications, where the container, when opened, forms an integral support portion and covering portion of the erected enclosure.
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BACKGROUND OF THE INVENTION
a) Field of the Invention
The present invention relates to a method of manufacturing a semiconductor device, and more particularly to a technique allowing a semiconductor integrated circuit to reliably operate at a low voltage.
b) Description of the Related Art
In connecting a region in a semiconductor substrate to a wiring formed on the substrate, a highly doped region is generally formed in the surface of the substrate, and thereafter a wiring is connected to the surface of the highly doped region. As the material of wiring, metal, silicide, doped silicon, and other materials are used.
If a wiring is made of polycrystalline silicon or amorphous silicon, a simplified connection structure may be adopted. Specifically, a silicon electrode is first formed on the surface of a semiconductor substrate, and thereafter ions are implanted in the silicon electrode and semiconductor substrate adjacent thereto. The doped silicon electrode and doped region of the substrate contact slightly at the interface therebetween. Heat treatment at the later process diffuses impurities in the doped silicon electrode and substrate region toward the non-doped region under the silicon electrode, and electrical interconnect therebetween is established.
The above processes are advantageous in that they can be performed at the same time when a gate of a MOS transistor is formed and then ions are implanted to the source and drain regions.
Recent semiconductor integrated circuits with very fine patterns have a demand for a low voltage operation of the circuits. As the operating voltage lowers, a voltage difference between high and low levels (logic swing) becomes small and the circuit operation becomes likely to become unstable.
A circuit may become unstable at a low voltage such as 3 V or 3.3 V even if it operates stably at an operating voltage of 5 V.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a semiconductor device manufacturing technique capable of providing a stable operation of a semiconductor integrated circuit even at a low voltage.
According to one aspect of the present invention, there is provided a semiconductor device including: a semiconductor substrate having a surface region of a first conductivity type; a conductive film directly formed on part of a surface of the surface region, the conductive film containing impurities of a second conductivity type opposite to the first conductivity type; an oozed diffusion or out-diffusion region of the second conductivity type formed by outward diffusion of the impurities in the conductive film, the oozed diffusion region being formed at an area contiguous to the conductive film in the surface region; a low resistivity region of the second conductivity type extending from an area adjacent to the conductive film in the surface region and overlapping the conductive film; and a double-diffused drain (DDD) structure transistor comprising a first gate electrode formed on a gate insulating film over a channel region defined by an area in the surface region, first source and drain regions of the second conductivity type formed on both sides of the first gate electrode, and second source and drain regions of the second conductivity type surrounding, and being formed deeper than, the first source and drain regions and overlapping the first gate electrode, wherein a length of a portion of the low resistivity region overlapping the conductive film is substantially the same as a length of a portion of the second source and drain regions overlapping the first gate electrode.
According to another aspect of the present invention, there is provided an SRAM semiconductor device including a parallel circuit of two serial circuits each having a driver transistor and a load, a wiring for connecting an interconnection point between the driver transistor and the load of each serial circuit to a gate electrode of the driver transistor of the other serial circuit, and a transfer transistor connected to each interconnection point, wherein the two driver transistors and two transfer transistors are each formed by a MISFET having a channel region formed in an active region of a first conductivity type in a surface of a semiconductor substrate, source and drain regions formed on both sides of the channel region, and an insulated gate electrode formed over the channel region, the SRAM semiconductor device including: a pair of wirings containing impurities of a second conductivity type opposite to the first conductivity type, each of the wirings being directly formed on part of a surface of the active region where the two driver transistors are formed; and a double-diffused drain (DDD) structure MISFET having a channel region defined in an active region of the first conductivity type in the surface of the semiconductor substrate, source and drain regions of a DDD structure formed on both sides of the channel region and having shallow source and drain regions and deep source and drain regions enveloping said shallow source and drain regions, and an insulated gate electrode formed over the channel region, and wherein regions where one of the source and drain regions of the two driver transistors, which is connected to the wiring, is formed to overlap the wiring from an end thereof, and a length of a portion of the source and drain regions overlapping the wiring is substantially the same as a length of a portion of the deep source and drain regions of the DDD structure overlapping the insulated gate electrode from an end thereof.
A low resistivity region doped with impurities and connected to a wiring directly formed on the surface of a semiconductor substrate adjacent to the low resistivity region, is formed by the same process of forming deep source and drain regions of a DDD structure. Impurities having a relatively large diffusion coefficient may be doped in the deep source and drain regions of the DDD structure. Therefore, impurities in the low resistivity region diffuse deeply and at the same time creep under and overlap the wiring. As a result, the connection area of the wiring and low resistivity region becomes large and the contact resistance can be lowered.
If the connection structure of the wiring and low resistance region is applied to the connection structure of a wiring and source and drain regions of a driver transistor of an SRAM semiconductor device, one of the source and drain regions of the driver transistor can be connected to a constant potential with a low contact resistance. It is therefore possible to provide an SRAM capable of reliably operating even at a low supply voltage.
If a DDD type MISFET is formed on the same chip, the semiconductor device capable of reliably operating at a low voltage can be formed by changing mask patterns without increasing the number of manufacturing processes.
As described above, a low resistivity region doped with impurities and a wiring directly formed on the surface of the semiconductor substrate adjacent to the low resistivity region can be electrically connected with a low contact resistance. Accordingly, it becomes possible to provide a semiconductor device capable of reliably operating even at a low voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A to 1D are cross sectional views of substrates illustrating the structures of connection between a wiring and a low resistivity region.
FIG. 2 is a layout of a monitor circuit manufactured for evaluating embodiments of the invention.
FIGS. 3A and 3B are a circuit diagram of an SRAM cell to which the connection structure of an embodiment of the invention is applied, and a plan view of the SRAM cell on a semiconductor substrate.
FIGS. 4A to 4E are cross sectional views of a substrate taken along one-dot chain line IV--IV of FIG. 3B, explaining the processes of a method of manufacturing an SRAM cell by applying the connection structure of an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The inventor has estimated the reason for an unstable operation of an integrated circuit at a low voltage to be ascribed to a large contact resistance between a wiring and a low resistivity region. The wiring is made of polycrystalline silicon or other materials and formed by the same process as that of forming a gate electrode of a MISFET, and the low resistivity region is formed thereafter by ion implantation.
Referring to FIGS. 1A to 1D, conventional connection structures between a wiring and a low resistivity region will first be described, and then connection structures between a wiring and a low resistivity region according to embodiments of the invention will be described.
FIG. 1A is a cross sectional view of a substrate showing the conventional connection structure between a wiring and a low resistivity region. A wiring 2 of polycrystalline silicon is formed on the surface of a semiconductor substrate 1. The wiring 2 is formed by the same process as that of forming a gate electrode of a MISFET on another region of the substrate 1. An outwardly diffused or oozed diffusion region 4 is formed just under the wiring 2 by outward diffusion of impurities from the wiring 2 to the substrate 1 by heat treatment performed after the wiring 2 was formed.
Low resistivity regions 3 are formed on both the sides of the wiring 2 by ion implantation. The low resistivity region 3 may be formed at the same time when the source and drain regions of MISFET are formed together with the doping of a polycrystalline silicon gate. Since ion implantation is performed after the wiring 2 was formed, no low resistivity region is formed just under the wiring 2. However, in addition to a small lateral diffusion at the time of ion implantation, later heat treatment causes impurities to diffuse in the lateral direction. This lateral diffusion region overlaps the oozed diffusion region 4.
The wiring 2 and the low resistivity regions 3 are electrically connected together by an overlap region 5 of the low resistivity region 3 and oozed diffusion region 4. If thermal hysteresis is different, diffusion of the oozed diffusion region 4 and low resistivity region 3 becomes different. If the area of the overlap region 5 becomes small because of variation of diffusion, the contact resistance becomes high.
The source and drain regions of a transistor, particularly in recent semiconductor devices with very fine patterns, are made shallow in order to alleviate the short channel effect. There is therefore a tendency that the resistance of the overlap region 5 is becoming smaller and smaller.
FIG. 1B shows the conventional connection structure between a wiring and a low resistivity region wherein a MISFET of a lightly doped drain (LDD) structure is formed in another region of the semiconductor substrate.
A wiring and low resistivity regions on both the sides of the wiring are formed by the same processes as those of forming a gate electrode and source and drain regions of MISFET of the LDD structure. Side wall regions 6 are therefore formed on the side walls of the wiring layer 2. A low concentration region 3a having an impurity concentration lower than the low resistivity region 3 is therefore formed just under the side wall 6.
The contact resistance becomes high because the low concentration region 3a is serially inserted between the wiring 2 and low resistivity region 3. As described above, if an LDD structure is formed in the same substrate, the contact resistance becomes higher than the case explained with FIG. 1A. As semiconductor devices are made finer and finer, an LDD structure is often used so as not to deteriorate the device performance by hot electrons. An increase of the contact resistance between the wiring 2 and low resistivity region 3 may become a significant issue.
Next, with reference to FIGS. 1C and 1D, the fundamental structure according to embodiments of the invention will be described.
FIG. 1C shows a fundamental structure wherein a usual MISFET is formed in the same substrate. A deeper low resistivity region 7 is formed under a low resistivity region 3, the former region 7 enveloping or surrounding the latter region 3. Other structures are similar to those in FIG. 1A.
FIG. 1D shows another fundamental structure wherein a MISFET of an LDD structure is formed in the same substrate. Similar to FIG. 1C, a deeper low resistivity region 7 is formed under a low resistivity region 3, the former region 7 enclosing or surrounding the latter region 3. Other structures are similar to those in FIG. 1B.
The deeper low resistivity regions 7 shown in FIGS. 1C and 1D may be formed by doping impurities having a larger diffusion coefficient than that for the low resistivity regions 3, by doping impurities at different dose, or by subjecting them to thermal hysteresis more often than the low resistivity regions 3. The deeper low resistivity regions 7 can be formed by the same process as that of forming deep source and drain regions of a MISFET of double-diffused drain (DDD) structure if such MISFET is formed in the same substrate. Regions formed by the same process have equal depths and lateral diffusion lengths within a process tolerance. In this specification, this equality is called "substantially the same".
As described above, by forming the deeper low resistivity region 7 in the region adjacent to the wiring 2, an overlap region 5 between an outwardly diffused or oozed diffusion region 4 and a low resistivity region formed adjacent thereto can be made large. The contact resistance is considered to be increased correspondingly.
A monitor circuit was manufactured and resistance values were measured in order to evaluate the effects of reducing a contact resistance of the connection structure shown in FIG. 1D.
FIG. 2 is a plan view showing the layout of the monitor circuit for evaluating the effects of reducing a contact resistance. Wirings 2 and low resistivity regions 3 and 3a are alternately and serially connected as shown in FIG. 2. A deeper low resistivity region 7 such as shown in FIG. 1D is being formed at the connection region between the wiring 2 and low resistivity region 3 and 3a. Side wall oxide are not shown in the figure.
The wiring 2 is of a two-layer structure made of polycrystalline silicon layer having a thickness of 0.1 μm and tungsten silicide layer having a thickness of 0.1 μm. A length L 1 from one center of the connection region of the wiring 2 to the adjacent center is 3.4 μm and a width W 1 of the wiring 2 is 0.75 μm. A length L 2 from one center of the connection region under the wiring 2 to the center of the adjacent wiring 2 is 3.3 μm and a width W 2 of the low resistivity regions 3 and 3a parallel to the wiring 2 is 1.0 μm.
Next, with reference to FIG. 1D, the conditions of forming each low resistivity region will be described. The oozed diffusion region 4 was formed by implanting phosphorus (P) ions into the wiring 2 at an acceleration energy of 40 keV and at a dose of 6×10 15 cm -2 and thereafter by performing heat treatment twice at 900° C. for 10 minutes.
The low resistivity region 7 was formed by implanting phosphorus (P) at an acceleration energy of 40 keV and at a dose of 3×10 15 cm -2 , and the low resistivity region 3a was formed by implanting phosphorus (P) at an acceleration energy of 40 keV and at a dose of 4×10 13 cm -2 . The low resistivity region 3a was formed by implanting arsenic (As) at an acceleration energy of 50 keV and at a dose of 4×10 15 cm -2 . Each region was activated by performing heat treatment twice at 900° C. for 10 minutes. As indicated by broken lines 7a shown in FIG. 1D, the low resistivity region 7 was formed by implanting ions only in the regions having a width of 0.2 μm from both the ends of the wiring 2.
The side walls 6 were formed by depositing an oxide film having a thickness of 0.2 μm by chemical vapor deposition (CVD) and anisotropically etching it.
The monitor circuit shown in FIG. 2 having 50 connections regions, including 26 wirings 2 and 25 low resistive regions 7, was manufactured, and the resistance value across both the ends of the monitor circuit was measured. The resistance value of the monitor circuit was 15 kΩ. The resistance of one wiring 2 was about 70 Ω and the resistance of one low resistivity region was about 230 Ω. It is therefore understood that the resistance at one connection region between the wiring 2 and low resistivity region is about 150 Ω.
A similar monitor circuit having the connection structure of FIG. 1B was manufacture. The resistance at one connection region was about 250 Ω. It was found therefore that the resistance at the connection region could be lowered by about 40% by forming the deep low resistance region such as shown in FIG. 1C or 1D.
An embodiment which applies the fundamental structure shown in FIG. 1C to an SRAM cell will be described.
FIG. 3A is an equivalent circuit of an SRAM cell, and FIG. 3B is a plan view showing a layout of the circuit of FIG. 3A formed on a substrate.
As shown in FIG. 3A, a load resistor L1 is serially connected to the drain terminal D1 of a driver transistor Tr1 to constitute a serial circuit. A terminal of this serial circuit on the load resistor L1 side is connected to a power source voltage V DD , and the source terminal S1 of the driver transistor Tr1 is connected to ground potential GND. Similarly, a serial circuit of a load resistor L2 and a driver transistor Tr2 is formed and connected across the power source voltage V DD and ground potential GND.
An interconnection point X1 between the drain terminal D1 of the driver transistor Tr1 and the load resistor L1 is connected to the gate electrode G2 of the other driver transistor Tr2. An interconnection point X2 between the drain terminal D2 of the driver transistor Tr2 and the load resistor L2 is connected to the gate electrode G1 of the other driver transistor Tr1.
The interconnection point X1 is also connected via a transfer transistor Tr3 to a bit line Bl1. Similarly, the interconnection point X2 is also connected via a transfer transistor Tr4 to a bit line BL2. Both the gate electrodes G3 and G4 of the transfer transistors Tr3 and Tr4 are connected to a word line WL. The terminals of the transfer transistors Tr3 and Tr4 connected to the interconnection points X1 and X2 are called source terminals S3 and S4, and the terminals thereof connected to the bit lines BL1 and BL2 are called drain terminals D3 and D4 in the specification.
As shown in FIG. 3B, active regions A1 and A2 are defined by a field oxide film formed on the surface of a silicon substrate. The driver transistors Tr1 and Tr2 and transfer transistor Tr4 are formed in the active region A1, and the transfer transistor Tr3 is formed in the active region A2. The gate, source, and drain of each transistor is represented by suing the same reference symbols (character and number) as those of a corresponding terminal shown in FIG. 3A.
The gate electrode G1 of the driver transistor Tr1 is connected at a connection region C1 to the source region S4 of the transfer transistor Tr4 and to the drain region D2 of the driver transistor Tr2. The connection region is a region where the surface of the silicon substrate is exposed by removing the gate oxide film formed on the surface of the active region.
The gate electrode G2 of the driver transistor Tr2 is connected at a connection region C2 to the source region S3 of the transfer transistor Tr3, and at a connection region C3 to the drain region D1 of the driver transistor Tr1. The source regions S1 and S2 of the driver transistors Tr1 and Tr2 are connected at a connection region C4 to a ground line GND.
Although not shown in FIG. 3B, the load resistors L1 and L2 are formed over an interlayer insulating film along the gate electrodes G1 and G2. One ends of the load resistors L1 and L2 are connected to the gate electrodes G1 and G2 near the connection regions C1 and C2. The other ends of the load resistors L1 and l2 are connected to a power source line formed in the same layer as the resistors L1 and L2 along the GND line.
Bit lines are formed in the lateral direction of FIG. 3B over an interlayer insulating film covering the load resistors L1 and L2 and power source line, along the gate electrodes G1 and G2. The bit lines are connected to the drain regions D3 and D4 of the transfer transistors Tr3 and Tr4 via contact holes.
The fundamental structure shown in FIG. 1C is utilized at the connection regions C1 to C4 of FIG. 3B.
Next, with reference to FIGS. 4A to 4E, a method of manufacturing an SRAM cell such as shown in FIG. 3B will be described. FIGS. 4A to 4E are cross sectional views taken along one-dot chain line IV--IV of FIG. 3B. A cross sectional view explaining the process of forming a MOSFET Tr5 of a DDD structure in another region of the same substrate is shown, by reference, at the right side of each cross sectional view.
FIG. 4A is a cross sectional view of a substrate after a process of forming openings of connection regions. A p-type well 10 is first formed on an n-type silicon substrate. Although only a p-type well is formed, other wells may also be formed. Isolating oxide regions 11 are formed to a film thickness of about 400 to 500 nm at predetermined areas by local oxidation.
An SiN film used as a mask for local oxidation is removed, and the surface of the exposed p-type well 10 is thermally oxidated to form a gate oxide film 12 to a thickness of about 20 nm. The gate oxide film 12 at the regions corresponding to connection regions C1 and C4 is removed by utilizing photolithography. In the above manner, the connection regions C1 and C4 are defined.
FIG. 4B is a cross sectional view of the substrate after a process of implanting ions for deep source and drain regions of a transistor having a DDD structure. A polycrystalline silicon layer is deposited to a thickness of about 300 nm over the whole surface of the substrate by CVD. Next, phosphorus ions are implanted in the polycrystalline silicon layer at an acceleration energy of 30 to 70 keV and at a dose of 1×10 15 to 10×10 15 cm -2 .
The polycrystalline silicon layer is patterned to form the gate electrode G1 of the driver transistor Tr1, the gate electrode G4 of the transfer transistor Tr4, and the ground line GND at the connection region C4. At this time, the gate electrode G5 of MOSFET having a DDD structure is formed.
Instead of the polycrystalline silicon layer, a two-layer structure of a polycrystalline silicon layer and a tungsten silicide layer may be used. For example, a polycrystalline silicon layer is deposited to a thickness of 100 nm, and a tungsten silicide layer is deposited thereon to a thickness of 100 nm.
Other layers may also be used for the conductive layer G, which include a single layer structure of an amorphous silicon layer, a two-layer structure of a polycrystalline silicon layer and a silicide layer, a three-layer structure of an amorphous silicon layer, a polycrystalline silicon layer, and a silicide layer, a three-layer structure of a polycrystalline silicon layer, a silicide layer, and an amorphous silicon layer, and a four-layer structure of an amorphous silicon layer, a polycrystalline silicon layer, a silicide layer, and another amorphous silicon layer.
The region of MOSFET with the DDD structure and the connection regions C1 and C4 are exposed, and other regions are covered with a resist pattern 13. Next, by using the resist pattern 13 as a mask, impurity ions are implanted for forming the source and drain regions of MOSFET Tr5 with the DDD structure. In this ion implantation, impurity ions having a larger diffusion coefficient among the two kinds of impurities for the source and drain regions are used. For example, phosphorus ions are implanted at an acceleration energy of 30 to 70 keV and a dose of 1×10 15 to 5×10 15 cm -2 . With this impurity ion implantation, the deep source and drain regions S5a and D5a of MOSFET Tr5 with the DDD structure are formed. At this time, the low resistance regions 14 and 15 are formed at the connection regions C1 and C4.
FIG. 4C is a cross sectional view of the substrate after a process of forming shallow source and drain regions of MOSFET with the DDD structure and the source and drain regions of each transistor of the SRAM cell and forming an interlayer insulating film. The resist pattern shown in FIG. 4B is removed. By using the gate electrode of each transistor and the isolating oxide regions as a mask, impurity ions are implanted for forming the shallow source and drain regions of MOSFET with the DDD structure. In this ion implantation, impurity ions having a smaller diffusion coefficient among the two kinds of impurities for the source and drain regions are used. For example, arsenic ions are implanted at an acceleration energy of 30 to 70 keV and a dose of 1×10 15 to 10×10 15 cm -2 .
With this impurity ion implantation, the shallow source and drain regions S5b and D5b of MOSFET Tr4 with the DDD structure are formed. At this time, the source and drain regions S4 and D4 of the transfer transistor Tr4 and the shallow low resistivity region 15a over the low resistivity region 15 at the connection region C4 are formed. Part of the source region S4 is formed over the low resistivity region 14.
The source and drain regions are formed by the above processes through ion implantation. At this stage, impurities are not still activated, but they are activated by later annealing.
Next, an interlayer insulating film 16 of SiO 2 is deposited by CVD on the whole surface of the substrate to a thickness of about 100 nm. A contact via hole is formed by utilizing photolithography to expose the surface of the gate electrode G1 at a predetermined area.
FIG. 4D is a cross sectional view of the substrate after a process of forming load resistors and a power source line. A polycrystalline silicon layer 19 is formed by CVD over the whole surface of the substrate to a thickness of 100 nm. Impurities are doped into the polycrystalline silicon layer 19 at the region where the resistance is to be lowered. In this embodiment, by using a resist pattern as a mask, arsenic ions are implanted into the region along the ground line GND, for example, at an acceleration energy of 30 to 70 keV and a dose of 1×10 15 to 10×10 15 cm -2 . The lowered resistance region is used as the power source line.
After arsenic ions are implanted, annealing is performed at 900° C. for 10 minutes. This annealing activates the impurity ions implanted by the previous processes. At the region of MOSFET Tr5 with the DDD structure, phosphorus ions having a relatively large diffusion coefficient implanted at the process explained with FIG. 4B are deeply diffused and at the same time activated to thereby form the deep source and drain regions S5a and D5a. In addition, arsenic ions having a relatively small diffusion coefficient implanted at the process explained with FIG. 4C are slightly diffused and at the same time activated to thereby form the shallow source and drain regions S5b and D5b. The source and drain regions S4 and D4 of the transistor Tr4 are also activated.
With this annealing, phosphorus ions in the gate electrode G1 are diffused into the polycrystalline silicon layer 19 near at the connection region C1. Therefore, the gate electrode G1 and polycrystalline silicon layer 19 are electrically connected together by a low resistance region at the connection boarder therebetween.
Also at the connection regions C1 and C4, phosphorus ions implanted at the process explained with FIG. 4B are deeply diffused and activated so that the low resistivity regions 14 and 15 are formed. The low resistivity region 14 partially overlaps the source region S4 and is electrically connected thereto. At the connection region C4, impurities in the low resistivity region 15 are activated. The shallow low resistivity region 15a is connected, as shown in FIG. 3B, to the source region S1 of the driver transistor Tr1. Therefore, the low resistivity region 15 is electrically connected via the shallow low resistivity region 15a to the source region S1.
At the same time, at the connection regions C1 and C4, phosphorus ions in the gate electrode G1 and ground line GND in contact with the p-type well 10 are diffused into the p-type well 10 to thereby form the oozed diffusion regions 17 and 18.
Next, the polycrystalline silicon layer 19 is patterned to form the power source line and load resistors L1 and L2 (FIG. 3A). The power source line is formed along the ground line GND when viewed in the layout of FIG. 3B. One ends of the load resistors L1 and L2 are connected to the gate electrodes G1 and G2 near the connection regions C1 and C2 when viewed in the layout of FIG. 3B, and the other ends are connected to the power source line formed along the ground line GND.
FIG. 4E is a cross sectional view of the substrate after a process of forming bit lines. After the power source line and load resistors are formed by patterning the polycrystalline silicon layer 19, an interlayer insulating film 20 is formed by depositing by CVD an SiO 2 film to a thickness of about 100 nm and a phosphorus silicate glass (PSG) film to a thickness of about 500 nm. Reflow is performed thereafter at 900° C. for about 10 minutes to planarize the surface of the interlayer insulating film 20. With this heating, the low resistivity regions 14 and 15 and other regions activated by annealing at the process explained with FIG. 4D are further deeply diffused. Therefore, the contact resistance at the connection regions between the ground line GND and low resistivity region 15 and between the gate electrode G1 and low resistivity region 14 is further lowered.
Next, a contact hole is formed to partially expose the surface of the drain region D4 of the transfer transistor Tr4. An aluminum layer 21 is deposited to a thickness of about 1 μm by physical vapor deposition (PVD), and patterned to form the bit lines.
With the above processes, the SRAM cell shown in FIG. 3A can be formed.
At the same time when the deep source and drain regions S5a and D5a of the transistor Tr5 with the DDD structure are formed, the low resistivity regions 14 and 15 are formed at the connection regions. Therefore, the overlap regions between the low resistivity regions 14 and 15 and the oozed diffusion regions 17 and 18 just under the wiring and the gate electrode are made large. At the connection region C4 formed by the above processes, the length of the deep low resistivity region 15 creeping under and overlapping the GND line is considered to be about 0.3 to 0.4 μm, and the length of the shallow low resistivity region 15a creeping under the GND line is considered to be about 0.1 μm.
Since the overlap regions between the low resistivity regions 14 and 15 and the oozed diffusion regions 17 and 18 can be made larger, the contact resistance between the wiring formed at the same time when the gate electrodes are formed and the low resistivity region formed adjacent to the wiring can be lowered.
In a usual SRAM, transistors with the DDD structure are used for circuits which require a large source/drain breakdown voltage, such as an input protection circuit for preventing electrostatic breakdown and a redundancy circuit with fuses. Such circuits can be manufactures by the SRAM cell manufacturing method explained with FIGS. 4A to 4E without increasing manufacturing steps.
In the above embodiment, after ions are implanted for forming the deep source and drain regions of the DDD structure at the process explained with FIG. 4B, the resist pattern 13 is removed, and immediately thereafter ion implantation is performed for the shallow source and drain regions. Annealing may be performed between the processes of forming the deep and shallow source and drain regions. The deep low resistivity regions 14 and 15 are shown in FIG. 4D can be diffused deeper by this annealing. Therefore, the overlap regions between the oozed diffusion regions 17 and 18 and the low resistivity regions 14 and 15 can be made larger and the contact resistance can be further lowered.
If annealing is performed between the processes of implanting impurity ions for the double source and drain regions of the DDD structure, the same species of impurity ions may be used.
The DDD structure may also be formed by vapor phase diffusion or by deposition of diffusion species and drive-in, instead of ion implantation. Also in this case, either two kinds of impurities having different diffusion coefficients may be diffused at the same time, or the same kind of impurities may be diffused twice.
In the method described with FIGS. 4A to 4E, a MOSFET with a single drain structure is used as the transistor of an SRAM cell. A lightly doped drain (LDD) structure may be used. In forming an LDD structure, after the process illustrated in FIG. 4B, the resist pattern 13 is removed and LDD regions are formed before ion implantation is performed for the shallow source and drain regions S5b and D5b.
By using the gate electrode of each transistor as a mask, phosphorus ions are implanted at an acceleration energy of 40 keV and at a dose of 4×10 13 cm -2 . Next, an SiO 2 film is deposited to a thickness of about 200 nm by CVD, and anisotropically etched by reactive ion etching or other methods to form side wall oxide regions on the side walls of the gate electrodes. Thereafter, the processes same as the process illustrated in FIG. 4C and the following process are performed.
The LDD structure can prevent a device performance from being deteriorated by the hot electron effect accompanied by fine pattern devices.
In the methods explained with FIGS. 4A to 4E, impurities implanted in the deep source and drain regions of the DDD structure are also implanted to all the connection regions. Impurities may be implanted only into limited connection regions. For example, impurities may be implanted only into the connection region C4 at which the ground line GND is connected.
For example, the low resistivity region 14 shown in FIG. 4E is formed also at the partial area of the source region S4. It is conceivable that the shape of the source region may change and the transistor characteristics may be adversely affected.
The connection regions C1, C2, and C3 shown in FIG. 3B overlap the isolating oxide regions. Therefor, impurity ions for forming the low resistance region are also implanted into the area near the boarder between the active region A1 and the isolating oxide region. Impurities implanted into the area near the boarder creep under the isolating oxide region at the later annealing. Therefore, the isolation function may be damaged. To solve these possible problems, deep ion implantation can be arranged not to be performed at the connection regions C1, C2, and C3.
As above, although the embodiment of the invention lowers the contact resistance between a wiring and a low resistivity region, the adverse effect may occur depending on a connection region where ions are implanted. Whether or not the embodiment of the invention is applied, is preferably determined from a trade-off between the lowered resistance and the adverse effect at each connection region.
The present invention has been described in connection with the preferred embodiments. The invention is not limited only to the above embodiments. It is apparent to those skilled in the art that various modification, improvements, combinations and the like can be made without departing from the scope of the appended claims.
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A semiconductor device capable of stably operating even at a low voltage, includes: a semiconductor substrate having a surface region of a first conductivity type; a conductive film directly formed on a surface of the surface region at an area thereof, the conductive film containing impurities of a second conductivity type opposite to the first conductivity type; an oozed diffusion region of the second conductivity type formed by diffusion of the impurities in the conductive film into the substrate, the oozed diffusion region being formed at an area contiguous to the conductive film in the surface region; a low resistivity region of the second conductivity type extending from an area adjacent to the conductive film in the surface region and overlapping the conductive film; and a DDD structure transistor formed on another region of the surface region, wherein a length of a portion of the low resistivity region overlapping the conductive film is substantially the same as a length of a portion of the deep source and drain regions of the DDD structure overlapping the gate electrode.
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This application is a Rule 53(b) continuation of U.S. patent application Ser. No. 08/821,505, to Khosravi-Sichani et al., filed on Mar. 21, 1997 and now U.S. Pat. No. 5,983,217.
BACKGROUND OF THE INVENTION
This invention relates to replicated database network architecture. More particularly, the invention relates to providing even loadsharing of queries among the replicated databases in the network.
In the early 1980's, centralized databases called network control points (NCP) were introduced into signaling networks by AT&T to support the credit card calling service and 800 service. The network architecture with these network control points allowed intelligent network services for providing call handling information in response to network queries.
The network control points for the 800 service, for example, are deployed throughout the United States to support the Data Base 800 Service mandated by the Federal Communication Commission. In the network architecture for such 800 service, 800number calls are routed from a local router or end office to a network switch which launches network queries to the Network Control Point. The network control point translates the 800 number to a routing number and returns the routing number to the network switch. The network switch subsequently routes the call to an appropriate network carrier based on this routing number.
The network control points are designed to accommodate growth and additional services. For example, the network control points are designed as high-capacity systems handling more than one million queries per hour. Also, alternate billing services (ABS) such as a collect calling service and a bill-to-third number calling service have been implemented using the network control point architecture. The network control points comprise replicated databases containing the same records for reliability reasons against natural disasters such as fire and flood.
With an increasing number of communication services introduced into the network and increasingly sophisticated services, developing a scheme to insure that queries are handled evenly among available network control points is an important task. For example, where the control points comprising a set of replicated databases in the telecommunication network receive a large volume of queries that can be handled at any of the replicated databases, it is essential to direct incoming queries only to available databases.
It is therefore an object of this invention to provide reliable methods and networks that can handle a large volume of queries to the distributed applications.
It is a more particular object of this invention to provide methods and networks that can evenly loadshare queries amongst available databases containing the same software and data.
SUMMARY OF THE INVENTION
These and other objects of the invention are accomplished in accordance with the principles of the invention by providing an even loadsharing of queries in a network architecture with replicated databases with ability to respond to its network conditions. The network includes a round-robin routing table having correlated index numbers, point codes and addresses of the replicated databases. The network architecture responds to incoming queries with searching of the round-robin routing table by incrementing to a successor index number. For example, a switch in a communication network may respond to incoming queries with searching of the round-robin routing table. Alternatively, a transfer node in a telecommunication network designed for routing messages between switches and databases may respond to incoming queries with searching of the round-robin routing table. The searching of the round-robin routing table provides an available address of the database where the query is directed.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified block diagram of illustrative network which can be operated in accordance with this invention.
FIG. 2 is an illustrative embodiment of input and output of a round-robin routing engine of this invention.
FIG. 3 is an illustrative round-robin routing table which can be utilized in accordance with this invention.
FIGS. 4a-b (collectively referred to as FIG. 4) is a flow chart of steps for carrying out an illustrative embodiment of this invention.
FIG. 5 is a flow chart of steps for carrying out another illustrative embodiment of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the illustrative embodiment shown in FIG. 1 a representative communication network architecture for querying replicated commercial databases is shown. As used in this application, a Segmentation Directory ("SD") refers to an exemplary network control point or replicated database added to a conventional telecommunication network. The SDs generally contain the same software and customer data and are used to locate service processors or network application processors which perform intelligent network services based on dialed numbers. A Signal Transfer Point ("STP") refers to a high-capacity packet switch for routing signaling messages between switches and databases such as SDs. Lucent 4ESS® ("4ESS") is a representative switch in a telecommunication network.
The illustrative Communication Network 100 of the present invention includes a set of SDs, STPs and 4ESS which are interconnected via Signaling System 7 ("SS7") links that normally function at 56 kb/s in North America and at 64 kb/s in Europe. It is not a requirement that the SDs are all interconnected to the STPs, but is shown here for simplicity. For example, SD 1 102 could be connected only to STP 1 108 while SD 2 104 is connected only to STP 2 110. Since each of SDs perform the same application and contain an identical copy of customer data, 4ESS switch 112 can send a query to any of SDs which can correctly process the query and respond to the query.
The preferred embodiment of the present invention provides 4ESS switch 112 to implement a round-robin algorithm to evenly loadshare incoming queries among the replicated SD 1 102, SD 2 104 and SD 3 106. Thus, 4ESS switch 112 would send the query for the first call received to SD 1 102. The next call would result in a query to SD 2 104, and the following call would result in a query to SD 3 106. 4ESS switch 112 in performing the round-robin algorithm accounts various factors such as the SD's SS7 route accessibility, SD's SS7 route congestion status and SD application availability as described in greater detail hereinbelow.
Alternative embodiment of the present invention allows the round-robin algorithm to be executed at the mated pair of STP 1 108 and STP 2 110 in order to alleviate the processing burden on 4ESS switch 112. The implemented algorithm for STP 1 108 and STP 2 110 is almost identical to the algorithm implemented in the 4ESS switch (112 described above. The distinction is described in reference to FIGS. 4 and 5.
FIG. 2 shows illustrative Input 200 and Output 204 of 4ESS switch 112, (FIG. 1) where Round-robin algorithm 202 of the present invention is implemented. As shown, the left column lists the headers of Input 200 entered into 4ESS switch 112 (FIG. 1) and the right column lists the headers of Output 204 generated from 4ESS switch 112 (FIG. 1). These headers are all part of the same message that has to be routed. The content of Input 200 and Output 204 may be categorized into at least the following types of headers: Message Transfer Part ("MTP") Header 206 and 210, Signaling Connection Control Part ("SCCP") Header 208 and 212, and Translation Capabilities Application Part ("TCAP") Header 214 and 216.
MTP Header 206 and 210 each may include, but not limited to, the following parameters: Destination Point Code ("DPC"), Originating Point Code ("OPC") and Signaling Link Selection ("SLS"). DPC is the address to which a message is to be sent. OPC indicates the source of the message so that the response to the query can be returned to the signaling point that originated the message. SLS is used to load-share signaling messages across a link set in the SS7 network. SCCP Header 208 and 212 each may include the following parameters: Message Type, Class of Service and Called Party Addresses. In a typical SS7 routing, there is a function called a Global Title translation which is used for a higher level routing of, for example, 800 queries. The Global Title translation is also used for a call that requires the round-robin routing of the present invention for even load-sharing. TCAP Header 214 and 216 each may include Application Query Information, that is a part of protocol for calling application. It conveys most of the application specific information from switch to database so that the database can respond to a query.
For example, an incoming call requiring a query to a database, needs to know the address to which to send the query. For a call that requires round-robin routing of the query, the DPC of such a call is set to 4ESS switch 112 (FIG. 1) itself. If the switch has the round-robin routing table, the 4ESS switch 112 (FIG. 1), then, looks at the Routing Indicator in the Called Party Address. The Routing Indicator may be set to point code routing or global title routing. If the call is related to a global title routing, then, 4ESS switch 112 (FIG. 1) looks into the Translation Type and Global Title Address of the Called Party Address. If the Translation Type and Global Title Address indicate round-robin routing, then 4ESS switch 112 (FIG. 1) determines that the round-robin routing algorithm 202 should be used and proceeds with Input 200 to do a lookup on the round-robin routing table which is discussed in reference to FIG. 3. The lookup provides Output 204 that includes the DPC pointing to a particular database. The database is denoted SD n that can be any of SD 1 102, SD 2 104 or SD 3 106 (FIG. 1). The query is, thereafter, sent to the selected SD n by 4ESS switch 112 (FIG. 1). The database, SD n , in return processes the query and sends the response to the query back to 4ESS switch 112 (FIG. 1).
FIG. 3 illustrates exemplary Round-robin routing table 300 that includes columns of Index numbers 302, Point Codes 304 and Subsystem Numbers 306. The index numbers range from 0 to n-1 and account for n replicated databases SD n in Network 100 (FIG. 1) available to an incoming query at 4ESS switch 112 (FIG. 1). The point codes provide key pieces of information directing to a corresponding database. Also, the subsystem numbers are provided since in each database, there may be multiple subsystems with different applications including, for example 800 service, private network service, etc.
FIG. 4 is a flow chart having an illustrative sequence of steps in accordance with the preferred embodiment when the round-robin routing algorithm is implemented at 4ESS switch 112 (FIG. 1).
In step 400, 4ESS switch 112 (FIG. 1) receives an SS7 message for routing. This SS7 message is Input (FIG. 2) having MTP 206 (FIG. 2) and SCCP 208 (FIG. 2) information. From such information, 4ESS switch 112 (FIG. 1), in step 402, determines if the SS7 message requires a Global Title Translation, for example, required for the 800 service to translate an 800 number to an SS7 network address of the database that would perform the application to translate the 800 number to a conventional routing number. In order to determine the requirement of the Global Title translation, 4ESS switch 112 (FIG. 1) checks the routing indicator of SCCP Header 208 (FIG. 2). If the routing indicator is set to 1, the SS7 message does not require routing on the Global Title. If the SS7 message does not require the Global Title routing, then 4ESS switch 112 (FIG. 1) in step 404 performs point code routing that does not involve the round-robin algorithm.
On the other hand, if the routing indicator is set to 0, it requires routing on the Global Title. If the SS7 message requires the global title routing, then 4ESS switch 112 (FIG. 1) in step 406 determines if the Global Title translation requires the use of the round-robin routing algorithm by checking the Translation Type and Global Title Address in SCCP Header 208. If the Translation Type is set to other Global Title Translation such as a 800 service or private network service, 4ESS switch performs the specified routing in step 408. If the Translation Type and Global Title Address is set to round-robin routing, 4ESS switch 112 searches Round-robin table 300 (FIG. 3) as discussed in reference to FIG. 3. Thus, generally both the Translation Type and Global Title Address are used to determine round-robin routing.
The 4ESS switch 112 (FIG. 1) in step 410 utilizes modulus n counter such that n starts at zero and is incremented by one through to n-1, at which pointer n returns to zero on the next count. Each Index, n, points to data in the table containing the Point Code or MTP Destination Point Code ("DPC") and Subsystem Number or SCCP Subsystem Number ("SSN") addresses for the specific replicated database as shown in table 300 (FIG. 3).
More specifically, PC O represents a pointer to the last Point Code 304 (FIG. 3) and Subsystem Number 306 (FIG. 3) to which a query was sent for a call. This pointer PC O , is used in case a re-query is required for this same call. A re-query would be required if no response was received for the initial query. PC O is used to ensure a re-query is not sent to the same database. PC I represents the current position of the pointer to index, n. PC L represents the pointer used for the previous query that required round-robin routing. The pointer PC.sub. is incremented by one in step 410 so it would be set to the next count of PC L .
In step 412, 4ESS switch 112 (FIG. 1) determines if this query is a repeat of the first query, for a specific call at the 4ESS. For example, if no response was received for the initial query of a call, a re-query will occur. If 4ESS switch 112 (FIG. 1) determines that the present query is a re-query, then 4ESS switch 112 (RIG. 1) checks in step 414 if PC I =PC 0 , i.e. if Point Code Index points to the original Point Code that was queried when the call first came into 4ESS switch 112 (FIG. 1). If it is determined that PC I =PC 0 , then 4ESS switch 112 in step 416 increments Index by one so that the query is directed to the next database.
In step 418, 4ESS switch 112 (FIG. 1) determines if PC I =PC L +1, i.e. if the pointer points to the database which was successfully queried by the previous query sent from switch. This checks whether the pointer ends up back where it started its query routing inquiry in table 300 (FIG. 3).
If the pointer points to where 4ESS switch 112 (FIG. 1) started its query sequence in table 300 (FIG. 3), then 4ESS switch 112 (FIG. 1) provides an error message in step 420. This error message is called an SCCP error. Otherwise, 4ESS switch 112 (FIG. 1) returns to step 412. If 4ESS switch 112 (FIG. 1) determines that the present query is not a re-query in step 412 4ESS switch 112 in step 422 determines whether a function called skip control is activated. The skip control is a manual control that is used by a network manager to cause queries not to be sent to a particular address because of, for example, a maintenance problem detected in the database located at that particular address. If 4ESS switch 112 (FIG. 1) determines that the skip control is active, 4ESS switch 112 (FIG. 1) proceeds to step 416 to try the database at the next address by incrementing the counter. In step 418, 4ESS switch 112 (FIG. 1) determines whether the Point Code Index points to the original pointer value when the algorithm was entered. If it points to the same database again, 4ESS switch 112 (FIG. 1) prompts an error message in step 420. If the pointer does not point to the same database, 4ESS switch 112 (FIG. 1) loops back to step 412.
Otherwise, 4ESS switch 112 (FIG. 1) determines in step 424 if the SS7 route from 4ESS switch 112 (FIG. 1) to SD n (FIG. 1) is MTP route inaccessible. MTP route inaccessibility is represented in the algorithm as Transfer Prohibited ("TFP"). For example, STP 108 and STP 110 (FIG. 1) may send TFP message to 4ESS switch 112 (FIG. 1) so as to indicate inaccessibility to a particular database. If TFP message is received on all routes to the database, i.e. MTP route is inaccessible, 4ESS switch 112 (FIG. 1) proceeds to step 416 to increment the counter.
Otherwise, 4ESS switch (FIG. 1) in step 426 determines if the destination is Subsystem Prohibited ("SSP"), i.e. an SSP message has been received. SSP message indicates that there is a problem with a particular Subsystem Number, such as one SD among all SDs. If SSP message is received, 4ESS switch 112 (FIG. 1) proceeds to step 416 and increments the counter.
Otherwise, 4ESS switch 112 (FIG. 1) in step 428 determines if it is MTP route congested, referred to here as "TFC". If it is MTP route congested, 4ESS switch 112 (FIG. 1) determines in step 430 if a network control is in place to allow the 4ESS switch 112 to continue to search the round-robin table for available addresses, known as an "expansive control." If the expansive control is not active, no further search of the round-robin routing table is made in order to protect the network and an SCCP error message is sent to the originator of the query in step 432. Further, the query message is discarded and a relevant measurement is pegged.
If there is no MTP route congestion in step 428, 4ESS switch 112 (FIG. 1) in step 434 determines if a network application overload ("NM") control is in effect. If an NM control is in effect, 4ESS switch 112 (FIG. 1) determines in step 436 if an NM expansive control is in place for the NM control. If the expansive control is not in place then per step 438 the 4ESS switch 112 (FIG. 1) is notified of the action, a measurement is pegged and the query is discarded. If the expansive control is in effect, then 4ESS switch 112 continues the search on round-robin routing table in step 416.
If no NM control is in effect in step 434, 4ESS switch 112 (FIG. 1) in step 440 (FIG. 4b) uses the available address at the Pointer to populate the Message Transfer Part ("MTP") Destination Point Code ("DPC") and Signaling Connection Control Part ("SCCP") Called Party Address ("CdPA") Subsystem Number ("SSN"). In step 442, 4ESS switch 112 (FIG. 1) routes the message on the route determined by the MTP routing tables and the signaling link derived from the MTP SLS tables. In step 444, the index where the address found to route this query is set to PC L . PC L is used for the next query that arrives at the 4ESS switch 112 (FIG. 1) that requires round-robin routing.
In step 446, PC O is set to the index at the Pointer, PC I so that the address at which PC I is presently set is not used in case a re-query is required. In step 448, the PC O is reported to the originating process that created the query. This report is stored with the call register for the call in case of a re-query.
The process ends in step 450.
The order of the steps in FIG. 4 is not critical. For example step 426 can occur earlier in the process (e.g., between steps 422 and 424).
FIG. 5 shows adaptation of the method of FIG. 4 to an alternative embodiment utilizing an STP processor instead of 4ESS switch processor. Thus, the mated pair of STPs 108 and 110 (FIG. 1) process the round-robin routing algorithm 202 to evenly distribute queries among SD 1 102, SD 2 104 and SD 3 106 (FIG. 1). Many of the steps in FIG. 5 are the same or similar to steps in FIG. 4, except the 4ESS switch 112 (FIG. 1) specific steps 412, 414, 434, 436, 438, 446 and 448 (which are enclosed in dotted rectangulars in FIG. 4). The correspondence of steps is indicated by use of the same last two reference number digits for the same or similar steps in FIGS. 4 and 5. Thus, the discussion of steps in FIG. 5 can be somewhat abbreviated because more extensive discussion has already been provided for corresponding steps in FIG. 4.
In step 500 (similar to step 400 in FIG. 4), STP 108 or 110 receives an SS7 message via 4ESS switch 112 (FIG. 1). STP 1 108 or STP 2 110 (FIG. 1) in step 512 determines if the SS7 message requires a global title translation. More specifically, STP 108 or 110 (FIG. 1) look up the routing indication in SCCP header 208 (FIG. 2) of the SS7 message to determine the need for global title routing. If the routing indicator indicates that it does not require a global title routing, STP 1 108 or STP 2 110 (FIG. 1) in step 504 performs point code routing in the SS7 network.
If the routing indicator indicates the global title routing, STP 1 108 or STP 2 110 (FIG. 1) in step 506 determines if the round-robin routing is specified. STP 1 108 or STP 2 110 (FIG. 1) looks up the translation type and global title address in the SCCP header. If the translation type and global title address is set to any global title address translation types other than that requiring round-robin routing, then STP 1 108 or STP 2 110 in step 508 performs the specified global title translation.
If the translation type and global title address indicates round-robin routing is required, then STP 1 108 or STP 2 110 (FIG. 1) in step 510 increments the index number of the last successful query in the round-robin routing table 300 by one.
In step 522, STP 1 108 or STP 2 110 (FIG. 1) determines if the skip control function is in effect. If STP 108 or 110 determines that the skip control is turned on, STP 1 108 or STP 2 110 (FIG. 1) in step 516 increments the index number in Round-robin routing table 300 (FIG. 3) by one again so that the point code would point to the next available database.
In step 518, STP 1 108 or STP 2 110 (FIG. 1) confirms that the point code does not point to the same database that has been pointed after step 510 and already checked. If it is the same database that has been already checked, STP 1 108 or STP 2 110 (FIG. 1) in step 520 prompts an error message. Otherwise, STP 1 108 or STP 2 110 (FIG. 1) returns to step 522.
Remaining steps 524, 526, 528, 530, 532, 540, 542, 544 and 550 are respectively similar to corresponding steps in FIG. 4 and therefore do not need to be described again.
It will be understood that the foregoing is only illustrative of the principles of the invention and that various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. For example, to reiterate, some specific examples of possible uses of the invention include controlling access to computer systems, transaction processing systems, voice mail or voice response systems, and secured facilities such as buildings, prisons, military installations, and other high security locations. The invention may be employed only for certain users such as administrators or other super users.
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The apparatus and method of the present invention provides even loadsharing of round-robin querying of replicated databases in a network architecture which responds to network conditions. The network architecture utilizes a round-robin routing table that includes correlated index numbers, point codes and addresses of the replicated databases. The network architecture responds to incoming queries with searching of the round-robin routing table by incrementing to a successor index number and an associated point code. The network architecture may further determine whether the database at the address pointed by the point code is accessible. If not, the network architecture increments to another successor index number to locate an accessible database. When an accessible database is found, the point code is set to the address of the accessible database and the query is forwarded to that address.
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CROSS REFERENCE TO RELATED APPLICATION
The current application claims priority to and the benefit of U.S. Provisional Patent Application Ser. No. 61/602,019 filed Feb. 22, 2012, entitled “BRIDGE STYLE FRACTIONATION PLUG”. This reference is incorporated in its entirety.
FIELD
The present embodiments generally relate to a bridge plug for use in isolating fractionation zones in a wellbore.
BACKGROUND
A need exists for a fractionation plug which can avoid being preset in the wellbore while simultaneously separating the wellbore into separate zones.
A further need exists for a fractionation plug that can quickly and securely engage with the crown of another fractionation plug, which can prevent fractionation plugs from spinning during drill-out.
The present embodiments meet these needs.
BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description can be better understood in conjunction with the accompanying drawings as follows:
FIG. 1A depicts a mandrel according to one or more embodiments.
FIG. 1B depicts another mandrel according to one or more embodiments.
FIG. 1C depicts an additional mandrel according to one or more embodiments.
FIG. 2 is a perspective view of a fractionation plug according to one or more embodiments.
FIG. 3 is a cut view of the fractionation plug of FIG. 2 along line X-X.
FIG. 4A depicts a schematic of a first setting mechanism according to one or more embodiments.
FIG. 4B depicts a schematic of a second setting mechanism.
FIG. 4C depicts a schematic of a third setting mechanism.
FIG. 5 depicts a schematic of two fractionation plugs disposed within a wellbore.
FIG. 6 depicts a cross sectional view of a load ring disposed about a mandrel wherein one or more set screws are disposed through the load ring.
FIG. 7 depicts a tapered nose cone having a beveled distal end.
The present embodiments are detailed below with reference to the listed figures.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Before explaining the present apparatus in detail, it is to be understood that the apparatus is not limited to the particular embodiments and that it can be practiced or carried out in various ways.
The present embodiments generally relate to a bridge style fractionation plug.
The bridge style fractionation plug can be used in a wellbore and can include a mandrel.
An embodiment of the bridge type fractionation plug allows a work over team to pressure up on wellbore casing before perforating a fractionation zone to ensure that the plug is holding; enabling successful separation of two fractionation zones.
The bridge type fractionation plug does not allow fractionation fluids, sand, or chemicals to penetrate a zone below the bridge plug; preventing loss of fractionation fluids, thereby insuring maximum fractionation in the correct fractionation zone.
These plugs can be used for cement jobs in the wellbore due to the solid construction of the bridge plug.
The mandrel can include a crown engagement and a setting mechanism receiving end.
The crown engagement can have a diameter larger than the setting mechanism receiving end.
A mandrel shoulder can be formed between the crown engagement and the setting mechanism receiving end. A load ring can rest on the mandrel shoulder.
A first slip can be adjacent to the load ring. A first slip backup can be adjacent to the first slip. A first lubricating spacer can be adjacent to the first slip backup and a first secondary seal.
A primary seal can be adjacent to the first secondary seal. A second secondary seal can be adjacent to the primary seal.
A second lubricating spacer can be adjacent to the second secondary seal, which can include a second slip backup adjacent to the second lubricating spacer. The second slip can be adjacent to the second slip backup.
A removable nose cone can be disposed over the mandrel and can be adjacent to the second slip backup.
The removable nose cone can include a double bevel or tapered engagement. The tapered engagement can be composed of a first sloped face, a second sloped face, and a tapered face.
A central annulus can be formed in the center of the sloped faces of the tapered engagement. The tapered engagement can be integrated with a nose cone body which can form a pump down ring groove.
An embodiment can include a plurality of pressure relief grooves which can extend longitudinally. The pressure relief grooves can be disposed on an outer surface of the tapered engagement.
A facial seal can be formed in the setting mechanism receiving end of the mandrel where a bridge plug setting mechanism can be threaded into the setting mechanism receiving end between the facial seal and the removable nose cone.
The bridge plug setting mechanism can include a setting mechanism body which can engage the facial seal. The bridge plug setting mechanism can also include a setting mechanism load shoulder.
An extension can extend from the setting mechanism load shoulder into the removable nose cone. For example, in one or more embodiments the extension can be about 0.47 inches long from the setting mechanism load shoulder to the face of the extension.
Engaging threads can extend over an outer surface of the setting mechanism body. The engaging threads can extend at least a portion of the setting mechanism body.
The engaging threads can screw into the internal threads of the bridge plug setting mechanism receiving end.
The setting mechanism body can include a first bridge plug setting mechanism chamber with a first diameter and a second bridge plug chamber with a second diameter. The engaging threads can extend into a portion or the entire first bridge plug setting mechanism chamber.
The second diameter can be larger than the first diameter, which can create a bridge plug shoulder. For example, in one or more embodiments the first diameter can be 0.95 inches and the second diameter can be 1.145 inches.
Shear threads can be formed inside the second bridge plug chamber. Shear threads can allow for threadable connection between the setting mechanism and a setting tool, such as a wireline setting tool.
The bridge style fractionation plug can include a crown engagement that can be detachable from the mandrel. The crown engagement can have a plurality of grooves in the top portion, such as from about four grooves to about six grooves. The grooves can provide a secure engagement with the nose cone of an adjacent plug.
The bridge style fractionation plug can include a setting mechanism with left handed threads. The left handed threading can be used to prevent loosening of the bridge plug, such as when the setting tool is inserted and tightened into the second bridge plug setting mechanism chamber.
The bridge style fractionation plug can include a mandrel. A mandrel can be composed of a metal, a non-metallic composite, or combinations thereof, such as a mandrel made from a glass and resin composite.
The bridge style fractionation plug can include slips made from a metal, non-metallic, composite, or combinations thereof.
Turning now to the Figures, FIG. 1A depicts a mandrel according to one or more embodiments.
The mandrel 12 a can be used to form a portion of the bridge fractionation plug.
The mandrel 12 a can have a first end 102 and a second end 150 . The mandrel 12 a can have an overall length from 1 foot to 4 feet. The outer diameter of the mandrel 12 a can be from 2 inches to 10 inches.
The mandrel 12 a can have a crown engagement 20 formed in the first end 102 .
The first end 120 can have a first diameter that is larger than a second diameter of the second end 150 . For example, in one or more embodiments, the first diameter can be 0.75 inches and the second diameter can be 2.25 inches.
A mandrel shoulder 142 can be formed between the first end 102 and the second end 150 . The mandrel shoulder 142 can be of varying angles, such as from about 10 degrees to about 25 degrees.
The second end 150 can have a first setting mechanism receiving portion 152 a , which can have a facial seal 156 a and first internal threads 154 a . The facial seal can be made from an elastomer, urethane, TEFLON™ brand polytetrafluoroethylene, or similar durable materials. The facial seal 156 a can be one or more O-rings, E-rings, C-rings, gaskets, end face mechanical seal, or combinations thereof. The first setting mechanism receiving portion 156 a can be used when the operating pressure is less than 8,000 psi.
An anti-rotation ring groove 140 can be formed into the first end 102 . The anti-rotation ring groove 140 can secure an anti-rotation ring, not shown in this Figure, about the mandrel 12 a . The anti-rotation groove prevents the fractionation plug from becoming loose and falling off of a plug setting tool. The anti-rotation groove creates a tight fit between the anti-rotation seal and the fractionation plug setting sleeve. The anti-rotation ring can be made from elastomeric, TEFLON™ brand polytetrafluoroethylene, urethane, or a similar sealing material that is durable and able to handle high temperatures.
FIG. 1B depicts another embodiment of a mandrel 12 b . The mandrel 12 b can be substantially similar to the mandrel 12 a . The mandrel 12 b , however, can have a second setting mechanism receiving portion 152 b formed adjacent to the first end 102 . The second setting mechanism receiving portion 152 b can have one or more seals 159 . The second setting mechanism receiving portion 152 b can have one or more second internal threads 154 b . The second setting mechanism receiving portion 152 b can be used at any pressure.
FIG. 1C depicts another embodiment of a mandrel 12 c . The mandrel 12 c can be substantially similar to the mandrel 12 a , but can include the first setting mechanism receiving portion 152 a and the second setting mechanism receiving portion 152 b . The first setting mechanism receiving portion 152 a can have first internal threads 154 a . The second setting mechanism receiving portion can have second internal threads 154 b.
FIG. 2 is an isometric view of an illustrative fractionation plug according to one or more embodiments.
The fractionation plug can include a mandrel 12 , which can be any mandrel described herein. One or more slips, such as a first slip 310 and a second slip 312 can be disposed on the mandrel 12 .
The slips 310 and 312 can be made from metallic or non-metallic material. The slips 310 and 312 can have segments that bite into the inner diameter of a casing of a wellbore. The first slip 310 can be adjacent a load ring 380 , and the second slip 312 can be adjacent a removable nose cone 348 . The first slip 310 and the second slip 312 can be bidirectional slips, unidirectional slips, or any other slip configured that are used in downhole operations.
The mandrel 12 can also have one or more slip backups disposed thereon. A first slip backup 320 can be adjacent to the first slip 310 . At least a portion of the first slip backup 320 can be tapered to at least partially nest within a portion of the inner diameter of the first slip 310 . A second slip backup 322 can be adjacent the second slip 312 . At least a portion of the second slip backup 322 can be tapered to at least partially nest within a portion of the inner diameter of the second slip 312 . The slip backups can force the adjacent slip to expand into the inner diameter of the casing of the wellbore.
The slip backups can expand the first secondary seal 339 , the second secondary seal 341 , and the large primary seal 340 . These seals can be made of any sealing material. Illustrative sealing material can include rubber, elastomeric material, composite material, or the like. These seals can be configured to withstand high temperatures, such as from 180 degrees Fahrenheit to 450 degrees Fahrenheit.
A first lubrication spacer 342 and a second lubrication spacer 344 can be disposed on the mandrel 12 . The lubrication spacers can be made of a material that can allow free movement of the adjacent components such as TEFLON™ brand polytetrafluoroethylene, plastic, polyurethane. The first and second lubrication spacers are each tapered on one side and fit into the slip backups. The first and second lubrication spacers can range in length from 1 inch to 3 inches.
The first lubrication spacer 342 can be disposed adjacent the first slip back up 320 . The first lubrication spacer 342 can be disposed between the first slip back up 320 and the first secondary seal 339 .
The second lubrication spacer 344 can be disposed about the mandrel 12 adjacent the second slip backup 322 . The second lubrication spacer 344 can be disposed between the second secondary seal 341 and the second slip backup 322 .
The mandrel 12 can also have a removable nose cone 348 disposed thereon. The removable nose cone 348 can have one or more pressure relief grooves 359 formed therein. The removable nose cone 348 can be of various lengths and have faces of various angles. The removable nose cone can be 6 inches long and can have a first sloped face of 45 degrees and a second sloped face of 45 degrees tapering to a point together. The removable nose cone 348 can have a central annulus 352 . The diameter of the central annulus can range from ⅝ of an inch to 3 inches. The removable nose cone 348 can be disposed about or connected with the mandrel 12 opposite the crown engagement 20 . A pump down ring 360 can be disposed about the removable nose cone 348 .
The load ring 380 can be disposed about the mandrel 12 adjacent or proximate to the crown engagement 20 . The load ring 380 can reinforce a portion of the mandrel 12 to enable the mandrel 12 to withstand high pressures. The load ring 380 can be made from a composite material containing glass and epoxy resin or polyamide cured material that is able to be machined, milled, cut, or combinations thereof. The load ring can be from 1 inch to 3 inches in length and 2 inches to 8 inches in diameter.
FIG. 3 is a cut view of the fractionation plug of FIG. 2 along line X-X.
The fractionation plug 300 can have the mandrel 12 . The mandrel 12 can have a first setting mechanism receiving portion 152 a.
A setting mechanism 390 can be inserted in the first setting mechanism receiving portion 152 a . The setting mechanism can have a solid portion. The setting mechanism can threadably connect to the first setting mechanism receiving portion 152 a . The setting mechanism 390 can be any setting mechanism, such as those described herein.
The removable nose cone 348 can be supported by the mandrel, the setting mechanism 390 , or any combination thereof.
An anti-rotation ring 370 can be secured in the anti-rotation ring groove 140 .
The load ring 380 can rest on a mandrel a load ring seat 382 adjacent the load shoulder.
Also shown are pump down ring 360 , the pump down ring groove 359 , the first slip 310 , the second slip 312 , the first slip backup 320 , the second slip backup 322 , a large primary seal 340 , the first lubrication spacer 342 , the second lubrication spacer 344 , and the central annulus 352 .
The crown engagement 20 is also viewable in this Figure. The crown can be integral with the mandrel 12 as a one piece structure. In an embodiment, such as the 4½ inch in diameter mandrel, the crown can have 6 grooves formed by 6 points that extend away from the mandrel 12 , creating an engagement that securely holds another nose cone to the plug for a linear connection of two plugs in series.
FIG. 4A depicts a schematic of a first setting mechanism 400 according to one or more embodiments.
The first setting mechanism can have an extension 302 . The first setting mechanism can have a solid end 305 . The solid end 305 can be used to isolate zones in a wellbore.
The first setting mechanism 400 can have a load shoulder 301 . The load shoulder 301 and the extension 302 can support the removable nose cone.
The first setting mechanism 400 can have a one or more engaging threads 393 formed on an outer diameter thereof.
A first bridge plug setting mechanism chamber 309 can be formed in the bridge plug 400 . The first bridge plug setting mechanism chamber 309 can have a first diameter. A second bridge plug setting mechanism chamber 311 can also be formed in the bridge plug. The second bridge plug setting mechanism chamber can have a second diameter.
The first diameter can be less than the second diameter creating a stop shoulder 307 to allow the seating of a setting tool. The second bridge plug setting mechanism chamber can have shear threads 313 to engage with the setting tool.
FIG. 4B depicts a schematic of a second setting mechanism 600 .
The second setting mechanism 600 can include the extension 302 . The extension 302 can have one or more seal grooves 605 . The seal grooves 605 can support one or more seals 610 .
The second setting mechanism 600 can have the first bridge plug setting mechanism chamber 309 and the second bridge plug setting mechanism chamber 311 formed therein. The second setting mechanism 600 can have one or more shear threads 313 formed on an inner diameter of the second chamber 311 .
The second setting mechanism 600 can include a load shoulder 301 . The second setting mechanism 600 can also have one or more engaging threads 393 formed on an outer diameter thereof.
The second setting mechanism 600 can also include a tightening groove 324 . The second setting mechanism 600 can be engaged with the second setting mechanism receiving portion.
The second setting mechanism 600 can include the shoulder 307 that acts like a setting tool stop on the bridge.
FIG. 4C depicts a schematic of a third setting mechanism 700 .
The third setting mechanism 700 can have the extension 302 . The extension 302 can have one or more seal grooves 605 . The seal grooves 605 can support one or more seals 610 .
The third setting mechanism 700 can include a load shoulder 301 . The third setting mechanism 700 can also have one or more engaging threads 393 formed on an outer diameter thereof. The third setting mechanism 700 can also include a tightening groove 324 .
The third setting mechanism 700 can include a threaded chamber 710 that can have one or more shear threads 313 formed on an inner diameter thereof. The third setting mechanism 700 can include an additional chamber 705 .
FIG. 5 is a schematic of two fractionation plugs disposed within a wellbore 501 .
As depicted, the wellbore 501 can have a perforated casing 500 and two hydrocarbon bearing zones 530 and 532 .
The embodiments of the fractionation plug described herein can be used within casing or within production tubing. For example, in one or more embodiments, the fractionation plug can be used within the wellbore casing.
In operation, coil tubing, wire lines, or other devices, which are not shown, can be used to place the fractionation plugs 510 and 520 into the wellbore 501 . The fractionation plugs 510 and 520 can isolate the hydrocarbon bearing zones 530 and 532 from one another.
Once the plug is at a designated location, the setting tool can pull the mandrel, holding the outer components on the mandrel, which can compress the outer components, the slips, and the slip backups for engagement with the casing of the wellbore.
Once the plug is set in place, completion or workover operations can be performed.
FIG. 6 depicts a cross sectional view of a load ring disposed about a mandrel wherein one or more set screws are disposed through the load ring. The load ring 380 can be disposed about the mandrel 12 . One or more shear pins 700 a and 700 b can be disposed through the load ring 380 and engage the mandrel 12 . For example, the shear screws can extend ⅛ th of an inch into the mandrel 12 . The shear pins 700 a and 700 b can prevent premature movement of the load ring 380 .
FIG. 7 depicts a tapered nose cone having a beveled distal end. The removable nose cone 348 can have two slanted faces, one slanted face 709 is shown, and a pair of bevels 710 and 712 on a distal end thereof. The bevels 710 and 712 can be twenty degree bevels. The bevels help to reduce the risk of the removable nose cone 348 catching on a portion of a wellbore, reducing the likelihood of a premature set.
While these embodiments have been described with emphasis on the embodiments, it should be understood that within the scope of the appended claims, the embodiments might be practiced other than as described herein.
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A bridge style fractionation plug for use in a wellbore to separate a lower fractionation zone from an upper fractionation zone with no communication between the zones.
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CLAIM OF PRIORITY
[0001] This Application is a continuation under 35 U.S.C. §120 of earlier filed U.S. Non-Provisional Application Ser. No. 13/225,259, filed Sep. 9, 2011, by Susanna Lee, which claimed priority under 35 U.S.C. §119(e) from earlier filed U.S. Provisional Application Ser. No. 61/381,382, filed Sep. 9, 2010, by Susanna Lee, both of which are incorporated herein by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The current disclosure relates to faucet attachments generally and specifically to faucet attachments used to enable people to effectively gain access to water that would otherwise be beyond their arm reach.
[0004] 2. Background
[0005] When children are young it is common for parents to assist their children in reaching water faucets. Like adults, children need to wash their hands, gain access to drinking water, or access tap water for countless other reasons. Unlike adults, children have a shorter arm reach which can interfere with the usage of faucets that are generally designed for adult use.
[0006] Some methods to solve this problem that have been used include direct parental assistance and the use of foot stools. There are distinct disadvantages to these methods. Adults sometimes are unable or unavailable to assist children, and foot stools require large amounts of floor space.
[0007] The problem is not limited to young children. People with disabilities, the elderly, people with dwarfism, people with arthritis or back pain, or other adults may find it difficult to reach the normal water-flow of a faucet. Users may also desire to alter the water-flow from a faucet to more easily water plants, fill a pet's water dish, or for many other reasons.
[0008] The solution to this problem is a device that can attach to a faucet and physically bring the water-flow from a faucet closer to the user rather than the user having to come closer to the water-flow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 depicts an embodiment of a faucet attachment device.
[0010] FIG. 2 depicts an exploded view a faucet attachment device, showing the underside of a trough member and a cross section of an attachment member.
[0011] FIG. 3 depicts an embodiment of a faucet attachment device without a faucet.
[0012] FIG. 4 depicts the back side of an embodiment of an attachment member.
[0013] FIG. 5 depicts an embodiment of a trough member where one portion of the trough member is made from more flexible material than the rest of the trough member.
[0014] FIG. 6 depicts an alternate embodiment of a faucet attachment device.
[0015] FIG. 7 depicts an embodiment of an extendable trough member
[0016] FIG. 8 depicts an embodiment of a trough member with protrusions.
[0017] FIG. 9 depicts an embodiment of an attachment member.
[0018] FIG. 10 depicts a top-down view of an embodiment of an attachment member.
[0019] FIG. 11 depicts an embodiment of a faucet attachment device that is secured to a faucet.
[0020] FIG. 12 depicts an alternate embodiment of a faucet attachment device that is secured to a faucet in an alternate way.
[0021] FIG. 13 depicts an embodiment of a faucet attachment device with decorative features.
[0022] FIG. 14 depicts an embodiment of a faucet attachment device with a removable faceplate.
[0023] FIG. 15 depicts an embodiment of a faucet attachment device with a temperature sensor, a temperature display, and a power source.
[0024] FIG. 16 depicts a circuit with a temperature sensor, a temperature display, and a power source.
DETAILED DESCRIPTION
[0025] FIG. 1 depicts an embodiment of a faucet attachment device 100 . The faucet attachment device 100 can comprise a trough member 102 coupled with an attachment member 104 . The trough member 102 can comprise a channel 110 and channel walls 116 118 running along the longitudinal edges of the channel 110 . The channel 110 can be partially open. The channel 110 can comprise an entrance 112 at one end, and an exit 114 at the opposing end. The entrance 112 can be narrowly formed or broadly formed depending on the desired application. The exit 114 can also be narrowly formed or broadly formed depending on the desired application. Some embodiments can comprise a tapered channel 110 . The tapering of the channel 110 can occur in either direction from the entrance 112 to the exit 114 . By way of a non-limiting example, in some embodiments the channel 110 can be tapered from a broadly formed entrance 112 toward a narrowly formed exit 114 . The channel 110 and the trough 102 can be any desired length.
[0026] In some embodiments, the channel walls 116 118 can be extensions of the channel 110 along the edges of the channel 100 , and can have a variety of shapes and sizes. In the embodiment shown in FIG. 1 , the channel walls 116 118 can be curved extensions of the channel 110 , such that a transverse cross section of the channel 110 and the channel walls 116 118 can be substantially a “U” shape. In alternate embodiments, the channel walls 116 118 can be separate components that can be coupled with the channel with glue, adhesives, tape, cement, screws, bolts, rivets, anchors, clips, brads, staples, or any other known or desired affixing mechanism. The channel walls can be straight, curved, wavy, thick, thin, flat, short, tall, or have any other desired characteristic. In some embodiments, the trough member 102 can be made of polypropylene, polyethylene, polyurethane, thermoplastic rubber, bamboo, recycled plastic, metal, or any other material or combination of materials that provides the desired strength, flexibility, durability, weight, water resistance, or other desired physical characteristic.
[0027] The attachment member 104 can comprise an attachment opening 106 . The attachment opening 106 can be configured to engage a faucet 108 . In some embodiments, the attachment opening 106 can be substantially the size of a transverse cross-section of a faucet arm. In alternate embodiments, the attachment opening 106 can be circular, semi-circular, square, oval, wider horizontally than vertically, or have any other size or shape. In some embodiments, the attachment member 104 can be made of polypropylene, polyethylene, polyurethane, thermoplastic rubber, bamboo, recycled plastic, metal, or any other material or combination of materials that provides the desired strength, flexibility, durability, weight, water resistance, or other desired physical characteristic. In some embodiments the attachment member 104 can be primarily comprised of one material. In alternate embodiments, the attachment member 104 can be comprised of a different, more flexible, material in the area surrounding the attachment opening 106 . In some embodiments, the entire attachment member 104 can be made of a flexible material, such that a user can apply pressure to the sides of the attachment member 104 and can thereby widen the attachment opening 106 such that a faucet 108 can pass through the attachment opening 106 .
[0028] FIG. 2 depicts the underside of the trough member 102 and a cross section of the attachment member 104 . In some embodiments, the attachment member 104 can comprise a slit 120 . The slit 120 can be formed in the shape of a transverse cross section of the trough member 102 , such that the entrance 112 of the trough member 102 can slide into the slit 120 in the attachment member 104 . The trough member 102 can comprise bumps or ridges 122 extending from the top or bottom sides of the entrance 112 . The slit 120 can comprise depressions 124 along the inside of the slit 120 . In operation, the entrance 112 of the trough member 102 can be inserted into the slit 120 . The depressions 124 inside the slit 120 can engage the bumps or ridges 122 of the trough member 102 . The interaction of the bumps or ridges 122 and the depressions 124 can create friction between the trough member 102 and the attachment member 104 and can keep the two members coupled. Alternatively, in some embodiments, the attachment member 104 can be permanently coupled with the trough member 102 via glue, adhesives, tape, cement, screws, bolts, rivets, anchors, clips, brads, staples, or any other known or desired affixing mechanism. In some embodiments, the attachment member 104 can be removably coupled with the trough member 102 by snaps, loops, hooks, clips, interlocking parts, pins, bands, screws, brads, buttons, or any other known or desired affixing mechanism. In still other embodiments, the attachment member 104 can be part of the same unitary body as the trough member 102 , such that they are not separate components.
[0029] In operation, the embodiment of the faucet attachment device 100 depicted in FIG. 1 can engage a faucet 108 by passing the faucet 108 through the attachment opening 106 of the attachment member 104 , such that the faucet 108 can be frictionally coupled with the attachment member 104 . The attachment member 104 can be adjusted to engage the faucet 108 in such a position that the trough member 102 can be positioned below the faucet 108 . When the faucet 108 is operated, water flowing from the faucet 108 can strike the trough member 102 at the entrance 112 . The water can be diverted from its natural course to instead flow along the channel 110 . The channel walls 116 118 can prevent the water from spilling over the edges of the channel 110 . The water can leave the channel 110 at the exit 114 and flow along a course more easily accessible to a user.
[0030] FIG. 3 depicts the embodiment shown in FIG. 1 without a faucet. In the embodiment shown in FIG. 3 , the attachment member 104 can comprise an extension piece 126 that extends into the attachment opening 106 . The extension piece 126 can have a variety of sizes and shapes, and can extend into the attachment opening 126 from any desired direction or angle. The extension piece 126 can be used to provide additional support to the attachment member 104 , to provide a tighter fit when the attachment opening 106 engages a faucet, to prevent water from spilling backwards along the channel 110 or behind the device, or for any other known or desired reason.
[0031] FIG. 4 depicts the back side of an embodiment of the attachment member 104 . In some embodiments, the attachment member 104 can comprise at least one structural support 128 coupled with the attachment member 104 . The at least one structural support 128 can be housed within the attachment member 104 , or coupled with any portion of the exterior of the attachment member 104 . The at least one structural support 128 can be an extension, ridge, bar, pole, bump, or any other known support component. In some embodiments, the at least one structural support 128 can be made of the same material that the attachment member 104 comprises. In alternate embodiments, the at least one structural support 128 can be made of a harder or more rigid version of the same material that the attachment member 104 comprises. In still other embodiments, the at least one structural support 128 can be made of a different material or combination of materials than the attachment member 104 comprises, such as polypropylene, polyethylene, polyurethane, thermoplastic rubber, bamboo, recycled plastic, metal, or any other material or combination of materials that provides the desired strength, flexibility, durability, weight, water resistance, or other desired physical characteristic. In some embodiments, the at least one structural support 128 can be an extension of the attachment member 104 such that the structural support 128 and the attachment member 104 are one unitary body. By way of a non-limiting example, the at least one structural support 128 can be molded into the back side of the attachment member 104 . In alternate embodiments, the at least one structural support 128 can be a separate component coupled with the attachment member 104 through adhesives, screws, snaps, interlocking parts, fitting the edges of the structural support 128 into holes or grooves within the attachment member 104 , or any other known or desired affixing mechanism. In some embodiments, at least one structural support 128 can be coupled at an angle with at least one other structural support 128 , at any point along any of the structural supports 128 . By way of a non-limiting example, in the embodiment shown in FIG. 4 , one structural support 128 is coupled with the attachment member 104 in a horizontal position below the attachment opening 106 and the extension piece 126 , and two other structural supports 128 extend vertically downward from the horizontal support 128 to the bottom of the attachment member 104 .
[0032] FIG. 5 depicts an embodiment of a trough member 502 in which one portion of the trough member 502 can be made from more flexible material than the rest of the trough member 502 . The trough member 502 can be substantially similar to the trough member 102 shown in FIG. 1 , and can comprise a channel 510 , an entrance 512 , an exit 514 , and channel walls 516 518 . The trough member 502 can have a variety of shapes and sizes. The trough member 502 can be made of polypropylene, polyethylene, polyurethane, thermoplastic rubber, bamboo, recycled plastic, metal, or any other material or combination of materials that provides the desired strength, flexibility, durability, weight, water resistance, or other desired physical characteristic. In some embodiments, the trough member 502 can be made of different materials with different flexibilities, such that some parts of the trough member 502 can have different flexibilities than other parts of the trough member 502 . By way of a non-limiting example, in the embodiments shown in FIG. 5 , the exit 514 can be made of a more flexible material than the rest of the trough member 502 , such that the exit 514 can droop when liquid flows over it. In some embodiments, the channel 510 can be substantially linear from the entrance 512 to the exit 514 . In alternate embodiments, the channel can droop, rise, swing left, swing right, have waves, have curves, have ridges, or have any other functional form known, convenient, or desired.
[0033] FIG. 6 depicts an alternate embodiment of a faucet attachment device 600 . The faucet attachment device 600 can comprise a trough member 602 coupled with an attachment member 604 . The attachment member can comprise an attachment opening 606 . The attachment member 604 can be one unitary component, or it can be coupled with a removable piece 630 . In some embodiments, the removable piece 630 can be removably coupled with the attachment member 604 via snaps, loops, hooks, clips, interlocking parts, pins, bands, screws, brads, buttons, or any other known or desired attachment mechanism. In alternate embodiments, the removable piece 630 can be coupled with the attachment member 604 by a hinge 632 located at a connection point 634 or any other desired location. In some embodiments, the removable piece 630 can extend across a gap within the attachment member 604 such that the removable piece 630 can form a part of the edge of an attachment opening 606 when the removable piece 630 is coupled with the attachment member 604 .
[0034] In operation, the removable piece 630 can be removed from the attachment member 604 . In alternate embodiments, the removable piece can be rotated away from the attachment member 604 via a hinge 632 at connection point 532 . The attachment member 604 can be positioned underneath a faucet arm, such that the trough member 602 is below the faucet. The removable piece 630 can be placed on top of the faucet arm and coupled with the attachment member 604 at connection point 634 via snaps, loops, hooks, clips, interlocking parts, pins, bands, screws, brads, buttons, or any other known or desired attachment mechanism.
[0035] FIG. 7 depicts an embodiment of a trough member 702 that can be comprised of at least two trough pieces 736 . In some embodiments, the at least two trough pieces 736 can interact with one another to extend the trough member 702 to a desired length. In alternate embodiments, the at least two trough pieces 736 can interact with one another to retract the trough member 702 to a desired length. In some embodiments, the at least two trough pieces 736 can interact with each other to extend or retract the trough member 702 to a preset intermediate length between a fully extended position and a fully retracted position, or to any desired intermediate length between a fully extended position and a fully refracted position. The at least two trough pieces 736 can comprise grooves 738 and groove inserts 740 . The groove inserts 740 of one trough piece 736 can slide inside the grooves 738 of an adjacent trough piece 736 . In some embodiments, the trough pieces 736 can comprise hollow cavities 742 , such that one trough piece 736 can slide along the grooves 738 and retract into, or extend from, the hollow cavity 742 of an adjacent trough piece 736 . In alternate embodiments, the at least two trough pieces 736 can interact by having trough pieces of different sizes engaged inside one another in a telescoping configuration, by interlocked sliding arms, or by any other known or desired extension or retraction method.
[0036] FIG. 8 depicts an embodiment of a trough member 802 . The trough member 802 can be substantially similar to the trough member 102 shown in FIG. 1 , and can comprise a channel 810 , an entrance 812 , an exit 814 , and channel walls 816 818 . The trough member 802 can also comprise one or more protrusions 844 . In the embodiment shown in FIG. 8 , one or more protrusions 844 can be located on the outwardly facing sides of the channel walls 816 818 . In alternate embodiments, one or more protrusions 844 may be located on the inwardly facing sides of the channel walls 816 818 , at the tops of the channel walls 816 818 , near the entrance 812 , or at any other location desired on the trough member 802 . The protrusions 844 can take a variety of forms, and can have a variety of shapes and sizes. In some embodiments, the protrusions 844 can be a button, resemble body parts such as ears, or take any other size or shape. The protrusions 844 can be made of polypropylene, polyethylene, polyurethane, thermoplastic rubber, bamboo, recycled plastic, metal, or any other material or combination of materials that provides the desired strength, flexibility, durability, weight, water resistance, or other desired physical characteristic. In some embodiments, the protrusions 844 can be more or less flexible than the rest of the overall structure.
[0037] FIG. 9 depicts an embodiment of an attachment member 904 . The attachment member 904 can comprise at least one end portion 946 , at least one open area 948 , and at least one faucet interaction region 950 . The open areas 948 can be apertures located within the end portions 946 . In some embodiments, one end portion 946 can be connected to another end portion 946 by at least one faucet interaction region 950 . In some embodiments, the end portions 946 can be removable from the faucet interaction regions 950 . The at least one faucet interaction region 950 can be one or more straps, bands, or any other mechanism capable of interacting with a faucet. The end portions 946 and the faucet interaction regions 950 can be made of polypropylene, polyethylene, polyurethane, thermoplastic rubber, bamboo, recycled plastic, metal, or any other material or combination of materials that provides the desired strength, flexibility, durability, weight, water resistance, or other desired physical characteristic. The end portions 946 can be made of a different material than the faucet interaction regions 950 . In some embodiments, the at least one faucet interaction region 950 can be made of a more flexible or stretchable material than the material used for the end portions 946 .
[0038] In the embodiment shown in FIG. 9 , two end portions 946 are connected by two faucet interaction regions 950 . The open areas 948 can be configured to engage protrusions similar to the protrusions 844 shown in FIG. 8 , thereby coupling the attachment member 904 to a trough member similar to the trough member 802 shown in FIG. 8 . The open areas 948 can have a variety of sizes and shapes. In some embodiments, the open areas 948 can be circular, rectangular, triangular, semi-circular, or have any other known or desired shape. In some embodiments, an open area 948 can be substantially the same size as a cross section of a protrusion 844 such that the open area 948 can engage the protrusion 844 snugly. In alternate embodiments, an open area 948 can be larger than the cross section of a protrusion 844 , such that the open area 948 can be easily engaged around or removed from the protrusion 844 . In some embodiments that have a plurality of open areas 948 , the open areas 948 can be the same size and shape, or have different sizes or shapes as desired.
[0039] FIG. 10 depicts a top-down view of an embodiment of an attachment member 1004 . The attachment member 1004 can comprise two end portions 1046 , an open area 1048 located within each end portion 1046 , and at least one faucet interaction region 1050 . The faucet interaction regions 1050 can be one or more straps, bands, or any other mechanism capable of interacting with a faucet. In the embodiment shown in FIG. 10 , there can be more than one faucet interaction region 1050 located behind each other so that only one is visible from the top-down viewpoint shown. The end portions 1046 can be coupled with the at least one faucet interaction region 1050 at one or more joints 1052 located at each end of each faucet attachment region 1050 . The joints 1052 can comprise a hinge, a ball and socket configuration, rotatably interlocking pieces, or any other mechanism that allows the end portions 1046 to rotate independently of the at least one faucet interaction region 1050 while remaining connected, such that the attachment member 1004 can have a tri-axial configuration. In operation, each end portion 1046 can be rotated to an angle suitable for the open area 1048 on the end portion 1046 to engage a protrusion such as protrusion 844 shown in FIG. 8 . The at least one faucet interaction region 1050 can be rotated to an angle suitable for it to secure around a faucet. All three components can be oriented at different angles as needed. In some embodiments, the joint 1052 can lock the three components into position after they are rotated to the desired angles. The joint 1052 can lock the components into position by having a hinge with a pin, a clip, interlocking pieces that snap into place at certain angles, or any other known or desired mechanism for locking a joint.
[0040] FIG. 11 depicts an embodiment of a faucet attachment device 1100 that is secured to a faucet 1108 . The faucet attachment device 1100 can comprise a trough member 1102 with at least one protrusion 1144 , and an attachment member 1104 with at least one faucet interaction region 1150 . In some embodiments, the faucet attachment device 1100 can be secured to the faucet 1108 by wrapping the at least one faucet interaction region 1150 above the faucet 1108 and connecting the attachment member 1104 to the at least one protrusion 1144 such that the trough member 1102 hangs below the faucet 1108 .
[0041] FIG. 12 depicts an alternate embodiment of a faucet attachment device 1200 that is secured to a faucet 1208 in a different way. The faucet attachment device 1200 can comprise a trough member 1202 with at least one protrusion 1244 , and an attachment member 1204 with at least two faucet interaction regions 1250 . In some embodiments, the faucet attachment device 1200 can be secured to the faucet 1208 by wrapping one of the faucet interaction regions 1250 above the faucet 1208 , wrapping another one of the faucet interaction regions 1250 below the faucet 1208 , and connecting the attachment member 1204 to the at least one protrusion 1244 such that the trough member 1202 hangs below the faucet 1208 . In alternate embodiments, the at least one faucet interaction regions 1140 can be looped around the faucet 1208 , spun to create a helix form that the faucet 1208 can pass through, or manipulated in any other fashion desirable to secure the overall faucet attachment device 1200 to a faucet 1208 .
[0042] FIG. 13 depicts an embodiment of a faucet attachment device 1300 having decorative features. The faucet attachment device 1300 can comprise a trough member 1302 , an attachment member 1304 , and an attachment opening 1306 . In some embodiments, the decorative features can be permanently formed parts of the faucet attachment device 1300 . In alternate embodiments, the decorative features can be removed from the faucet attachment device 1300 and interchanged with other decorative features as desired. In the embodiment shown in FIG. 13 , the decorative features include eyes 1354 and feathers 1356 located on the attachment member 1304 . In some embodiments, the attachment opening 1306 can be formed into the shape of a mouth, nose, or any other desirable feature. Some embodiments can include decorative features intended to make the faucet attachment device resemble an animal, such as a duck, cow, chicken, pig, or any other animal. Other embodiments can include decorative features intended make the faucet attachment device resemble cartoon characters, vehicles, plants, or any other desired design. In some embodiments, decorative features can include any other body part or facial characteristic, such as ears, noses, hair or any other desired characteristic. Decorative features are not limited to representations of facial features or body parts, and can include various color schemes, patterns, or any other desired design.
[0043] FIG. 14 depicts an embodiment of a faucet attachment device 1400 that can comprise a removable faceplate 1458 . The faucet attachment device 1400 can be substantially the same as the faucet attachment device 1300 shown in FIG. 13 , and can comprise a trough member 1402 , an attachment member 1404 , and an attachment opening 1406 . The removable faceplate 1458 can be decorated with a design. Various embodiments of the removable faceplates 1458 can feature pictures of faces, pictures of scenery, graphic designs, artwork, or any other desirable design. In some embodiments, the removable faceplate 1458 can be coupled with the faucet attachment device 1400 by fitting connection components 1460 into corresponding holes 1462 in the attachment member 1404 . In alternate embodiments, the removable faceplate 1458 can be coupled with the faucet attachment device 1400 by using snaps or hooks, sliding it into grooves within the trough member 1402 , by placing it into a windowed pocket coupled to the faucet attachment device 1400 , by attaching it to areas similar to the protrusions 724 shown in FIG. 8 , or by any other known or desired attachment mechanism. The removable faceplate 1458 can comprise a faceplate opening 1464 that can correspond with the attachment opening 1406 . In operation, a faucet arm can pass through both the attachment opening 1406 and the faceplate opening 1464 . In some embodiments, the structure of the removable faceplate 1458 can provide support to the attachment member 1404 when the faucet attachment device 1400 is connected to a faucet.
[0044] FIG. 15 depicts an embodiment of a faucet attachment device 1500 that can comprise a temperature sensor 1566 and a temperature display 1568 . The faucet attachment device 1500 can be substantially the same as the faucet attachment device 100 shown in FIG. 1 , and can comprise a trough member 1502 , an attachment member 1504 , and an attachment opening 1506 . The faucet attachment device 1500 can also comprise a power source 1570 configured to supply power to the temperature sensor 1566 and the temperature display 1568 in circuit. The power source 1570 can provide power to the temperature sensor 1566 and the temperature display 1568 . The power source 1570 can be a battery, a generator, a hydroelectric generator, a plug attached to an electrical outlet, or any other known or desired mechanism for providing power to a circuit. In some embodiments, the power source can comprise a switch to turn the power source on or off.
[0045] The temperature sensor 1566 can be located on or within the trough member 1502 , or anywhere else on the faucet attachment device 1500 . The temperature sensor 1566 can be a thermistor, thermocouple, resistive thermal device, or any other known or desired temperature sensor. The temperature display 1568 can be in the form of an LCD screen, LED lights, or any other known or desired display. In operation, the temperature sensor 1566 can measure the temperature of the water flowing down the channel of the trough member 1502 , and the water's temperature can be displayed to the user on the temperature display 1568 . In various embodiments the temperature can be displayed in terms of Fahrenheit or Celsius degrees, icons or colors indicating that the water is generally hot or cold, or any other known or desired method of indicating a temperature. The temperature display 1568 can be located anywhere on the faucet attachment device 1500 . In some embodiments, the temperature display 1568 can be integrated with decorative features that can be present on the device. For example, the eyes 1354 shown in FIG. 13 can include LED lights that glow red when the water is hot and green when the water is cold, thereby indicating when the water flowing from the device is safe for a user to touch. In alternate embodiments, the faucet attachment device 1500 may not have a temperature display 1568 that operates visually, but can indicate the water temperature to the user by broadcasting audio signals through a speaker, or through any other known or desired mechanism for indicating information. In still other embodiments, the temperature sensor 1566 can comprise a heat-sensitive material that changes color or appearance when exposed to heat, such that the temperature sensor 1566 can indicate a temperature to a user directly without a separate temperature display or a power source. The heat-sensitive material can be a thermochromatic or thermochromic coating, such as an ink, a paint, or a dye, applied to all or a portion of the trough member 1502 , a thermal paper, a thermochromic polymer, or any other known material that changes appearance when exposed to heat.
[0046] FIG. 16 depicts a circuit 1672 comprising the power source 1570 coupled with the temperature sensor 1566 and the temperature display 1568 shown in FIG. 15 . The circuit 1672 can transmit power between the components. In some embodiments, the circuit 1672 can transmit signals between the components. In some embodiments, the signals can include data transmissions, such as data transmissions regarding the temperature measured by the temperature sensor, the power level within the circuit, whether to display temperature in Fahrenheit or Celsius degrees, or any other type of data desired.
[0047] In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.
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A device and method for delivering water to a person who is unable to reach household or other types of water dispensing faucets. In some embodiments, the device comprises a trough for delivering the liquid and an attachment member for attaching the trough to a faucet.
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THE FIELD OF THE INVENTION
This invention is in the field of pipe plugging and more particularly in the field of the plugging of oil well casings which have been broken off above or below ground.
BACKGROUND
The prior art has used many methods of stopping the wild gushing of oil or gas from well casings. The way used in Kuwait after the war with Iraq is to pump large volumes of mud or cement down the well casing to make it quit flowing.
This method then requires expensive removal of the mud or concrete, such as by drilling.
Not only is this expensive, but is consumes much time. Hundreds of oil well casings have been broken off in Kuwait, many of them below ground where the top of the casing is covered by a pool of oil and cannot be seen.
The plugging system hereof provides the concept of an inflatable plug on a tube, the tube being inserted in the well and then the plug is expanded with a fluid such as water or a gas to stop the flow. The prior art has many concepts involving the use of inflatable plugs. But in all cases there are major differences in principle and structure from the system hereof.
Oil pressure is very great and the concept of a restrainer of stiff material is provided to hold the flexible plug in place against great pressure.
Remote control of release of pressure into the tube and from the tube are concepts provided herein.
For plugging oil wells on massive scale, it is important that an expensive crane not be tied up in working at a single well location except for a very short time. For that reason a two-clamp tube holder concept is provided herein, holding the inserted tube to the oil well casing so that the crane is freed to be moved to a different well until needed for the tube and plug removal.
When an oil well casing has been broken off deep in the ground, such as by a vandalism explosion, the system hereof is excellent. The plugging can be done by passing the plug tube down through the oil puddle above the casing, though the casing cannot be seen as this makes great difficulty. However to assist emplacement of the plug-tube into an underground well casing, a first step can be to lower a special funnel toward the casing. This can be done by attaching the funnel around the plug-tube. The wide downward end of the funnel is easier to guide onto the casing than the narrower plug-tube. As the funnel has a long support frame extending upward, the funnel frame can be put around the plug tube and then both are lowered together until the funnel engages the casing. The funnel then guides the plug into the casing.
The special funnel is then removed horizontally from the plug-tube by first opening hinging sections of the funnel and its frame. The funnel is then lifted out of the way.
After the flow has been stopped with the system hereof by the use of a gate stop valve, then a globe valve, not shown, can be put above, and attached to, the gate stop valve.
A globe valve is better for day-to-day flow regulation than a stop valve.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of an oil well casing with the pipe plugging system hereof inserted therein. Certain forward parts of the system and of the casing are broken away. The plug is shown in storage position.
FIG. 2 is a detail of the lower parts of FIG. 1 with portions broken away. The plug is shown in inflated, plugging position.
FIG. 3 is a view of a hinge connection with part of a hand and a connected path of the upper restrainer portion, as seen from the central axis of the plug tube.
FIG. 4 is a view in section of the parts of FIG. 3 as seen on a plane at a right angle to a pivot pin and through a center between the ends of the pivot pin.
FIG. 5 shows the well casing of FIG. 1 partly broken away to show the plug. Also at the top of the casing a value and anchor flange are shown in dotted lines on the plug-tube from which they are lowered to the full line positions shown. A holding system shown holds the tube in fixed position with respect to the well casing.
FIG. 6, shows a detail of a tube pressure holding and remotely controllable pressure release system with parts broken away.
FIG. 7 is a detail of a modified plug-lower-portion in a well casing, with forward halves of each broken away.
FIG. 8 is an exploded view of a remotely-controllable plug-tube-pressure-release-valve ball depressing system, shown in full lines in valve non-operating positions and in dotted lines in valve releasing position. This system replaces the air-pressure container and spear for pressure release mode. Near the top of FIG. 8, in dotted lines, is the same solenoid-plunger unit of FIG. 6, which is used to puncture an air pressure container by pressing it against a spear, but in FIG. 8, is used to depress a valve opener. FIG. 8 shows at its top, the plug of FIG. 6 in dotted lines. At the bottom of FIG. 8 is the same housing as seen in FIG. 6 but shown in dotted lines with the ball-pressing system hereof in a pressure release position.
FIG. 9 is a diagrammatic side elevation of a plug-tube-guide shown with a forward side removed and shown as attached to a plug-tube and in guiding position on an oil well pipe.
FIG. 10 is a detail showing an upper guide-spacer on a plug-tube-section, in perspective, with ends of legs broken away.
FIG. 11 is a perspective view of the guide in open disconnected position ready for removal from or attachment to a pipe.
FIG. 12 is a perspective view of a tube section with the lower guide-supporting-plug-tube spacer thereon. A slower tube positioner is shown with a shearable liner between the collar and the tube which engages a flange on the tube. A portion of a flange liner is broken away to show that the shearable liner extends completely under the flange and clear to the tube.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The pipe plugging system, or plugger 10 of this invention is shown in FIG. 1 and is for plugging a pipe 12 having an outer upper end 14 which is open and accessible.
The pipe 12 can be the casing 12 of an oil well from which upper parts have been previously removed by intention or by vandalism as in war. A broken rough surface is shown at the end 14 in FIG. 1. In FIG. 2 the end has been cut in a horizontal plane.
The outer upper end 14 of the pipe 12 is open and is accessible either above ground or by digging down to it.
A plug-carrying-tube 30 of this invention has an inner lower end 32 considerably into the pipe 12. The inner lower end of the tube 30, in fact the whole tube 30 most likely, is straight, whereby the tube 30 can be said to have a usually vertical central axis 36 inside the pipe 12.
In FIG. 2 an inflatable flexible plug 40 has an inner end 32 and an outer end 44, when the plug 40 is inflated.
The plug 40 has its outer upper end 44 open and its inner lower end 32 closed. The upper outer end 44 of the plug 40 has a hollow neck 50, FIG. 1.
The plug neck 50 is disposed around the inner lower end of the tube 30 whereby the plug neck 50 can receive plug inflation fluid, such as an expandable gas, from the tube 30.
In FIGS. 1 and 2, the plug neck 50 is received around the inner lower end of the tube 30 and is clamped thereagainst by a suitable attaching clamp 60, which extends around the outer upper end of a restrainer 80, whereby the clamp 60 holds both restrainer 80 and tube 30 onto the pipe 12.
The restrainer 80 has an upper outer collar portion 82 which is actually in horizontally spaced sections 81 whereby the sections 81 can move so that they can be effectively clamped against the tube 30.
An inflation assembly 70, seen only in FIG. 1, delivers gas or other fluid under pressure into the plug 40 to inflate an inner lower portion of the plug whereby the pipe or well casing 12 becomes plugged by expansion of the inner lower end portion of the plug out against the inner side wall of the pipe 12.
The restrainer 80 has a lower end section which surrounds a portion of the plug 40 during pipe-plugging-plug-inflated times.
The restrainer 80 has an inner lower end 83 farthest from the outer upper end 31 of the tube 30.
The inner lower end 83 of the restrainer 80 is movable with respect to the central axis 36 of the tube 30, and capable of assuming a contracted position, as in FIG. 1, during plug-deflated times, with all parts of an innermost portion 88, FIG. 1, of the restrainer 80 closer to the axis 36 of the tube 30 and is also capable of assuming an expanded restraining position with all parts of the inner end 32 of the restrainer 80 farther from the central axis 36 of the tube 30.
In FIG. 1 the central portion 91 of the plug 40 is shown in its upper-outer storage position extending upwardly into the lower end of the tube 30. To prevent the central plug portion 91 from being pressed upwardly to excess by oil pressure force, a perforated holder 92 is fixed to the tube 30 and extends horizontally across the tube 30 interior to limit upward stretching of the plug central portion.
The perforated holder 92 has vertical holes 93 therethrough permitting inflation air to pass through.
The restrainer 80 surrounds an outer portion of the plug 40 whereby a portion of the plug can move, during plug inflation through the restrainer 80.
The plug 80 has a peripheral portion 84, FIG. 2, spaced from the axis 36 during plug-inflated times. When the lower end of the restrainer 80 is in restraining position and the plug 40 is in an inflated state, the restrainer 40 is capable of blocking the plug 40 so that the majority of the periphery portion of the plug substantially cannot pass into unwanted positions on the outer side of the restrainer 40 above the lower end of the restrainer when the pipe to be plugged is of such a size as to provide a close fit with respect to the lower end of the restrainer 40.
The restrainer lower portion 88, FIG. 1, has many hands 102, each pivoted about a horizontal wrist-axis 104 tangential to the tube axis 36 and at one of many pivot pins 106 each holding one of many hands 102.
The hands 102 each have vertically spaced fingers 108, FIG. 2, which extend out horizontally to two opposite sides of a slender palm 110.
Each palm 110 is held by a pivot pin 106 to one of many legs 114 extending downwardly and inwardly from an upper restrainer portion 120, FIG. 2.
The fingers 108 of each hand 102 lap with respect to fingers 108 of adjacent hands 102. Each hand 102 moves independently.
Inflation of the plug 40 pushs the hands 102 out to engage the inner wall 122, FIG. 2, of the pipe 12 where they are stopped in positions causing the lower portion 88 of the restrainer 80 to have a frustro-conical shape, FIG. 2, holding peripheral parts of the plug 40 from passing upwardly around the outer edges of the restrainer.
In FIG. 1, the pressure assembly 70 is shown to have a gas-under-high-pressure container 130 in, and slidable vertically along the tube 12.
When a solenoid plunger assembly 134, diagrammatically shown in FIG. 1, is energized by a remote power supply, now shown, it presses the container 130 downward against an upwardly facing spear 138 mounted on a platform 140 fixed to the inner wall of the tube 30 and disposed inside the tube 30.
The platform 140 has vertical holes letting gas downward therethrough for plug inflation when the container 130 is punctuated by being pressed on the spear 138 by a plunger 146.
In FIG. 5, a gas pressure delivery unit is shown at 150 and delivers gas to the upper end of the tube 30 serving the same purpose as the tube 30 of FIG. 1. The unit 150 delivers gas to a vertical tube 30 which extends downwardly through a gate valve 170 having a control handle 171.
The tube 30 also extends through an attachment flange 162 and from there extends through an upper end of a pipe 12 which can be a vertical oil well casing. At the lower end of the tube 30 is a plugging system 180 which can be of the type shown in FIGS. 1 and 2, although it is only grammatically shown in FIG. 5.
Around the upper end of pipe 12 is a lower clamp 184 which has connectors 190 extending therefrom, and being at their upper ends connected to an upper clamp 194 which latter is tightly fastened about the tube 30.
The tube 30 is passed downward into the pipe 12. Then the clamp 184 is clamped onto an upper part of the pipe 12 at a place spaced from the top thereof.
Then the flange is welded onto the top of the pipe 12. So that a circular sealing weld is made around the pipe at 190.
The gate valve is attached to the flange 162 by bolts 192 each of which extend through one of many vertical holes in the lower end of the gate valve which are in registry each with another vertical hole through the flange 162.
Installation can be done in more than one way. In one way of installation, the tube 30 is lowered into the pipe 12 when the flange 162 and gate valve 170 are already slidably disposed on the tube 30 but are supported on the tube by removable means, not shown, temporarily, during the lowering of the tube 30 into the pipe.
After the tube 30 is in the pipe 12, then the device not shown, for holding flange 162, in place on the tube 30, is removed allowing the flange 162 to slide down into position, resting on top of the pipe 12.
Next, welding is done around the pipe at 190' to attach the flange 162 to the pipe.
After that, the valve 170 is released so that it can be allowed to slide down to engage the flange 162. Then bolts 192 are installed through holes in the valve 172 and flange 162 to fix the gate valve 172 to the top of the flange 162. Lastly, the clamps 184 and 194 can be installed together with the connection rods or connectors 190.
In FIG. 6 a detail of the gas supply assembly 150 is shown. Its housing 201 has a vertical opening 202 therethrough. At the upper end of the opening 202 is a plug 204 with external threads 206 threadedly securing the plug 204 to other threads 208 on the upper end of the inner wall of the opening 202.
At the lower end of the opening 202 are threads 218 which receive the threads 222 of a threaded upper end of the tube 30. Inside the opening 202 is a container 230 for gas under pressure. At the underside of the container 230 is a spear 232 on a platform 236 which is suitably fixed to the inner wall 212 of the opening.
The platform 236 has openings 242 therethrough extending vertically for letting gas from the container 230 pass downwardly into a check valve opening 248 which opening extends vertically through the check valve housing 250 suitably secured to the tip of the tube 30, and plugging the top of the tube 30, and fixed therein by suitable means, not shown.
In the check valve housing 250 is a check valve seat 262 receiving a check valve ball 264 urged upwardly into a closed position in the seat 262 by an urging spring 266. The seat 262 gas an opening 280 extending upwardly and it is adapted to receive pressure through a gas opening 242 through the platform 236, whereby, when the check valve ball 264 is in a downward open position, gas can pass from the container 230 through the gas openings 242 and past the check valve ball 264 into the tube 30.
In FIG. 6, rupturing of the gas container 230 happens when it is pushed downwardly by a plunger 284 of a solenoid and plunger assembly 290.
In FIG. 6, a second ball check valve for pressure release is shown at 300 and when depressed by means, not shown, can release pressure from the tube 30 until the gas is out of it for deflating the plugging system 180 of FIG. 5.
The tube pressure release valve 300 extends out through a side of the upper part of the tube 30 beneath the housing 201.
In FIG. 7, a special plug 310 is shown having a concave inner and lower wall 312 having a downwardly opening cavity 316 so that oil pressure catching in the cavity 316 will tend to cause the lower end of the plug to be drawn upwardly at its center. This causes the plug 310 to tend to spread out less horizontally to prevent the tendency of parts of the plug to travel upwardly around outer edges of a restrainer not shown in FIG. 7, such as the restrainer of FIG. 1. Although the restrainer is not shown in FIG. 7, it could be above the parts shown in FIG. 7.
In FIG. 7, steel reinforcing such as used in automobile tires can extend throughout the plug as seen at 320 when the plug is seen in cross-section.
As the plug 310 is otherwise made of resilient material, such as rubber, therefore, it is flexible, and can move from an upper outer storage position as in FIG. 1 to the pipe plugging position of FIG. 2.
To further tend to prevent the plug 310 from passing upwardly around the lower end of the tube 30, certain reinforcing ribs 330 and 332 can be used. The ribs 330 and 332 are actually thicker parts of the wall of the plug 310 made by horizontal circular hollow centers surrounding protrusions 330 extending inwardly from the wall of the plug 310 into its hollow interior 340.
Fluid under pressure for plug expansion can be gas but it could also be any other fluid, such as a liquid and water would do the job.
In FIG. 8, apparatus is shown for releasing gas pressure through the check valve 264 of FIG. 6. Such gas release is in the safest direction, which is vertical, straight upward.
To prepare for pressure-releasing, the plug 204 is removed from the tube 30.
Next, the solenoid-plunger assembly 290 is removed, then the container 230 of FIG. 6 and the platform 236, of FIG. 6, are both slid up and out of the tube 30. This is possible because the check valve ball 264 is holding back the great pressure.
Next, in FIG. 8, a valve-opener assembly 400 having a carrier or jacket 402 is slid down the tube 30 into the dotted line position in FIG. 8, resting on the check valve housing 250.
Next, the solenoid-plunger assembly 290 is then replaced into the tube 30 and the plug 204 is threaded back into place.
The valve-opener assembly 400, FIG. 8 has a jacket 402 having a larger upper opening 408 and a smaller lower opening 410.
The smaller opening 410 has a cylindrical wall 412 snugly slidably receiving and guiding a valve opening pressor 414 small enough to engage, and press into open position, the check valve ball 264 at times when the pressor 414 is in a down position as in dotted lines at the bottoms of the full-line, FIG. 8 upper, representation of the valve opener assembly 400.
The pressor 414 is connected to a vertically sliding pressor extension 416 of larger diameter than the pressor 414 and slidable in a bearing 420 attached to, and in, the lower end of the jacket 406.
At the top end of the pressor extension 416 is a push-head 424 which is of much larger diameter than the extension 416.
The push-head 424 is snuggly slidable vertically in a chamber 430 having a cylindrical wall 428, and is restrained by a circular ledge 430 to keep it in the jacket 406.
The solenoid-plunger assembly 290 of FIG. 8 is the same unit as shown in full lines in FIG. 6 and, when energized, is capable of pressing, with the plunger 284, the push-head 424 to cause the pressor 414 to open the valve.
The pressor extension 416 has a portion of lesser diameter called the valve opening pressor 414 snuggly fitting the smaller opening 410 whereby a spring 417 in a spring chamber 418 will exert a force against a lower wall 419 of the jacket 402 and against the pressor extension 416 for urging the pressor extension 416 and the push-head 424 upwardly to maintain the parts in the full line position of FIG. 8 for allowing the valve ball 264 of FIG. 8 to be in a closed position but when pressure from the solenoid plunger 248 presses the push-head 424 downwardly then the pressor 14 will be in the downward position shown in dotted lines in FIG. 8, wherein it holds the valve ball 264 in a valve open position.
The push-head 424 is snuggly slidable vertically in a chamber 430 having a cylindrical wall 428, and is restrained by a circular ledge 430 to keep it in the jacket 406.
When the valve-ball 264 is in open, downward, position
Gas pushing up past the valve ball 264 in FIG. 8, will flow past small spacer protrusions 440 and out through threaded ports 446 of FIGS. 6 and 8, at times when port-bolts 450 are removed as in FIG. 8.
When deflation of the plug 40 is complete, oil in the well-pipe 12 will rush up the well pipe 12, but this is temporary and harmless and will continue as the tube 30 is removed by a crane, not shown, or is pushed out by oil pressure out of the top of the gate valve 170 of FIG. 5.
Next, the gate valve 170 is closed and the work is then completed as flow is under complete control.
All this is possible because the flange 162 is welded to the circumference of the oil-well-pipe 30 holding the gate valve onto the oil well pipe, all while the plug 40 has oil-flow safely stopped.
In FIG. 8, an oil well casing 12 is shown with its upper end 502 far below ground level 504 where it is impossible to see the end 502 through the oil 506 in a cavity 508.
To help guide the tube 30 so that its plug 40 enters the oil-hidden top of the casing 12, a conical guide 510 is provided having a guide surface 512 inwardly inclining toward the tube axis 36, as the upper end of the surface 512 is approached.
The lower end of the guide surface 512 is of a substantially larger size than the well casing 12, to be easy for the guide surface 512 to be placed over the well casing 12 by means not shown.
The tube 30 is held centrally in the guide 510.
This partly done by an upper tube-positioner or spacer 520 having a central upper collar 524 having right and left half-sections 528 forming, when closed, FIG. 10, a vertical opening 534 which closely fits the tube 30.
A guide-frame 526, FIGS. 9 and 11, extends upwardly along the tube 30 from the conical guide 510 and has right and left frame sections 532 which, as seen in FIG. 11 are secured by a hinge 534.
The hinge 534 is at the rearward sides of the frame sections 532 for a pivoting about a vertical hinge-axis 538. The collar half sections 532 are held together at their forward ends by a releasable fastener 540 using a vertical pin 542 fitting in holes 544 of clasp lugs 546. The removal of the pin 542 from the lugs 546 permits opening of the guide 510 so that it can be removed from the tube 30.
The upper collar right half is secured to the guide-frame right section by a pair of braces.
The positioning of the tube 30 is further helped by a lower tube positioner 550.
The lower tube-positioner 550 has a central lower collar 554 best seen in FIG. 12 having right and left half sections 558, forming, when in collar closed position, FIG. 12, a vertical opening 560 which closely fits the tube 30. The collar 554 is formed at two parts, a strong outer portion and shearable liner assembly 568 having right and left half-sections 572.
In FIG. 12, a guide holding flange 580 extends around the tube 30 and is welded hereto at 582 to resist upward movement of the guide under the pressure of upwardly gushing oil.
The flange 580 gauges an upper side of the shearable liner assembly 568 and prevents upper movement of the guide if the liner 568 is not sheared.
The liner assembly 568 can be formed of a shearable babbitt metal or of thermal plastic, whatever has a sufficient strength to resist the pressure of gushing oil onto the guide sufficient to hold the guide in place on the tube 30.
As the guide is lowered with the tube 30 inside, the guide surface 512 will be easily centerable onto the top of the well casing 12.
Thereafter a downward motion of the tube 30 such as caused by mechanical means not shown will force the flange 580 against the shearable liner 568 causing it to shear. This shearing will allow then the tube 30 and its restrainer 80 to move on down into the casing 12, even though the guide 510 will not go down further.
In fact the guide 510 being freed from the flange 580 will move upward under the pressure of the gusher until such time as its upper collar 520 strikes a stop 590 fixed to the tube 30 as in FIG. 6 although perhaps easier seen in FIG. 9 where a similar stop 590 is fixed to the tube 30 by welding as at 592.
The conical guide 510 is seen in FIGS. 9 and 10 to have large openings 595 in it. These are permitted to allow oil to past therethrough to reduce the effective force of a gusher against the guide 510.
The collars 524 and 554 are connected by braces 594 and 596 respectively extending out to the inner side of the frame sections 532, to which latter of the braces are attached whereby each collar 524 and 554 is disposed centrally about the axis 36 as is also the guide surface 512, of the tube 30 and the restrainer 80.
In operation, first the oil can be bailed from the cavity 508 in order to be able to remove dirt away from the top of the oil casing 12; and next the tube 30 is lowered until the guide surface 512 has been received on the top of the pipe or oil casing 12. Next the tube 30 is pressed downward with sufficient force that its flange 512 shears the liner 572 causing parts to fall away.
The tube 30 is then pushed downwardly shearing the liner assembly 568, and then is pushed further downwardly until the restrainer 80 of FIG. 9 is in a desired position for the inflation of the plug.
At the time of the lowering or pressing down of the tube 30, the valve 170 of FIG. 5 and the flange 162 thereof are slidably disposed on the tube 30 of FIG. 5.
Next as seen in FIG. 6 an inflation system is put in operation, as it is disposed at the upper end of the tube 160 of FIG. 6 when the tube is pressed down towards the oil casing in the first place.
By operating the solenoid 290 of FIG. 6 by remote control, its plunger 284 presses downwardly on the pressurized gas container 230 causing it to be punctured against the spear 232 for releasing gas under pressure therefrom so that it passes through the passages 242 depressing the valve ball 264 and inflating the plug 40 or the modified plug 310 on FIG. 7, so that it moves from the storage position of FIG. 1 outwardly of the tube to plug the pipe or well casing 12.
With the well casing 12 securely plugged, the clamps 184 and 194 with connecting rods 190 can be put in the positions of FIG. 5.
Next, the flange 162 in FIG. 5 can be lowered to be around the upper side of the tube 30 where it is secured to the tube by means of welding at 190 prime. The clamps 184, 194, and the rods 190 can then be removed.
Next the tube 12 is removed upwardly through the valve 170 and taken away. During this a momentary escape of oil will occur.
The valve 170 is then shut and piping not shown can be connected for normal oil well operation.
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A pipe plugging system useful for plugging oil well pipes for stopping oil flow from an oil well pipe. An inflatable plug is insertable on a tube through the top of the pipe and is inflated by a fluid under pressure released into he plug to expand the plug against the pipe wall. A blocker at the lower end of a carrier conduit expands out to block upward expansion of the flexible plug to force the plug to press against the inside the oil pipe on all sides. A gauge valve is installed on the pipe, to control oil flow, while the well pipe is held shut by the plug. A check valve, installed in the top of the tube, holds pressure in the tube, but is openable by pressure from a remotely controlled valve opening assembly to deflate the plug for tube removal, leaving the pipe closable by the check valve to control flow through the pipe into useful places. A guide removably placed around the tube guides the tube into an oil well casing deep in a pool of oil.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This present application is a national stage filing under 35 U.S.C § 371 of PCT application number PCT/KR2016/001281 filed on Feb. 5, 2016 which is based upon and claims the benefit of priority to Korean Patent Application No. 10-2015-0020324 filed on Feb. 10, 2015 in the Korean Intellectual Property Office. The disclosures of the above-listed applications are hereby incorporated by reference herein in their entirety.
FIELD OF DISCLOSURE
[0002] The present invention relates to a machine tool which includes a ram spindle and a tool holder having improved structures, respectively.
BACKGROUND OF THE DISCLOSURE
[0003] Machine tools refer to machines used for the purpose of machining metallic or non-metallic workpieces (hereinafter referred to as the “base materials”) into desired shapes and dimensions by means of appropriate tools by using various types of cutting or non-cutting methods.
[0004] Furthermore, machine tools may be basically classified into turning centers configured to machine base materials by rotating the base materials and moving tools and machining centers configured to machine base materials by rotating tools and moving the base materials.
[0005] FIG. 1 is a view showing a machine tool in which a conventional ram spindle is disposed, and FIG. 2 is a perspective view showing the conventional ram spindle and a conventional tool holder which are coupled to each other.
[0006] Referring to FIG. 1 , in a conventional machine tool 10 , a turntable 2 is disposed, an auto tool changer (ATC) accommodated in an ATC accommodation part 6 and a column 8 are disposed on a base 1 , a cross rail 9 is disposed on the column 8 , and a ram carriage 5 is disposed on a side of the cross rail 9 .
[0007] A base material (not shown) to be machined is fastened to and rotated on the turntable 2 , and the ram carriage 5 is movable in a direction parallel to a ground surface by means of the cross rail 9 .
[0008] In this case, the ram carriage 5 is movable along a vertical transfer part 7 in a direction perpendicular to a ground surface. A ram spindle 4 is disposed at the distal end of the ram carriage 5 , and a head block 3 is disposed at the free end of the ram spindle 4 .
[0009] In other words, the ram spindle 4 disposed on the ram carriage 5 is moved along the cross rail 9 in the x-axis direction and along the vertical transfer part 7 in the z-axis direction, and is thus disposed at a location where a tool can machine the rotating base material through turning.
[0010] In this case, a tool holder 20 having a mounting depression 21 into which an insert (a tool) for machining a rotating base material is disposed may be mounted on the head block 3 . The tool holder 20 is mounted in or detached and replaced from the ATC inside the ATC accommodation part 6 depending on the machining path and shape of a base material.
[0011] However, the method of replacing the tool holder 20 of the conventional machine tool 10 requires a long replacement time, and increases the number of required tool holders 20 , thereby increasing the costs of the machine tool 10 .
[0012] Furthermore, the individual tool holders 20 have minute differences, and thus a problem with the reliability of the degree of precision may occur due to the differences in machining distance attributable to inserts mounted into the tool holders 20 .
SUMMARY
[0013] The present invention has been conceived to overcome the above-described problems, and an object of the present invention is to provide a machine tool which includes a plurality of inserts, thereby reducing tool holder replacement time, performing rapid and precise machining, and increasing productivity and cost competitiveness.
[0014] In order to accomplish the above object, the present invention provides a machine tool having a ram spindle and a tool holder, the machine tool including: a tool holder configured to include at least two inserts; and a ram spindle configured to fasten the tool holder in the state of clamping the tool holder and to rotate the tool holder in order to change the locations of the inserts.
[0015] The ram spindle may include: a housing configured to have an open surface in the lower side surface thereof; a center part rotatably accommodated inside the housing; a first outer part disposed outside the center part, and configured to be co-rotated with the center part; a second outer part disposed between the housing and the first outer part, and fastened to the housing; and an actuator unit accommodated inside the housing, and configured to be selectively movable upward and downward through the open surfaces of the center part and the first outer part.
[0016] The tool holder may include: a coupling part configured such that one end thereof is mounted on the ram spindle; and a mounting part configured such that at least two inserts are coupled to the free end thereof, and disposed on the other end of the coupling part.
[0017] Outer ribs protruding at equal intervals may be formed on the outer circumferential surface of the first outer part, a cavity may be formed in the other end of the coupling part, and inner ribs protruding to come into contact with an inner diameter of the first outer part or to be spaced apart at predetermined intervals may be formed on the inner circumferential surface of the cavity at equal intervals.
[0018] The outer diameter of one end of the coupling part defined by the cavity may be formed to be equal to that of the second outer part, and the inner diameter of the one end of the coupling part may be formed to be equal to or larger than that of the second outer part.
[0019] One or more protrusions may be formed on the first outer part; and depressions configured to be seated over the protrusions may be formed in the coupling part so as to correspond in number to the protrusions.
[0020] The protrusions may be formed adjacent to the outer ribs; and the depressions may be formed adjacent to the inner ribs.
[0021] A first protrusion and depression part and a second protrusion and depression part configured to be engaged with each other may be formed on the opposite surfaces of the second outer part and the coupling part, respectively, and may be engaged with each other when the center part and the first outer part are raised by the actuator unit.
[0022] At least two protruding keys may be disposed on the outer circumferential surface of the center part; and key coupling depressions configured to be engaged with the keys may be formed on the first outer part.
[0023] A guide protrusion formed to protrude may be disposed at the center of the cavity; and a guide depression corresponding to the guide protrusion may be formed in the center part.
[0024] The actuator unit may be disposed inside the center part or first outer part.
[0025] The actuator unit may include: a clamping passage configured to raise the center part; an unclamping passage spaced apart from the clamping passage, and configured to lower the center part; and a spring configured to provide restoring force in the direction in which the center part is raised.
[0026] The machine tool may further include an auto tool changer (ATC) configured to store the tool holder unclamped from the ram spindle.
[0027] The present invention can provide the machine tool which includes the ram spindle and the tool holder having the improved structures, respectively, so that the plurality of inserts is provided in the single tool holder and the locations of the inserts can be rapidly changed by changing whether to fasten the tool holder through the vertical movement of part of the ram spindle, thereby improving productivity and precision and also reducing the costs of products.
DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a view showing a machine tool in which a conventional ram spindle is disposed;
[0029] FIG. 2 is a perspective view showing the conventional ram spindle and a conventional tool holder which are coupled to each other;
[0030] FIG. 3 is a partial perspective view of a ram spindle according to an embodiment of the present invention;
[0031] FIG. 4 is a perspective view of a tool holder according to an embodiment of the present invention; and
[0032] FIG. 5A and FIG. 5B show side sectional views schematically illustrating states in which an actuator unit according to an embodiment of the present invention moves a center part and a first outer part in upward and downward directions.
DETAILED DESCRIPTION
[0033] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0034] Unless specifically defined, all terms used herein have the general meanings that would be understood by those skilled in the art. If the meaning of a term used herein conflicts with the general meaning of the corresponding term, the definition made herein is used.
[0035] However, the invention to be described below is intended merely to illustrate an embodiment of the present invention, and is not intended to limit the range of rights of the present invention. Throughout the specification, the same reference numerals designate the same components.
[0036] FIG. 3 is a partial perspective view of a ram spindle according to an embodiment of the present invention, FIG. 4 is a perspective view of a tool holder according to an embodiment of the present invention, and FIG. 5A and FIG. 5B show side sectional views schematically illustrating states in which an actuator unit according to an embodiment of the present invention moves a center part and a first outer part in upward and downward directions.
[0037] Referring to FIGS. 3 to 5A and 5B , a machine tool according to an embodiment of the present invention provides a ram spindle 100 and a tool holder 200 having improved structures, respectively.
[0038] The machine tool according to the present embodiment implements a tool holder configured to include at least two inserts and a ram spindle configured to fasten the tool holder in the state of clamping the tool holder and to rotate the tool holder in order to change the locations of the inserts, thereby rapidly, accurately and stably machining a base material.
[0039] More specifically, the ram spindle 100 may include a housing 110 , a center part 120 , a first outer part 130 , a second outer part 140 , and an actuator unit 150 .
[0040] The housing 110 may have an open surface in the lower side surface thereof, and may form the appearance of the ram spindle 100 . In this case, the lower side surface is named based on the states shown in the drawings, and may be any one side surface of the housing 110 , such as the upper side surface, left side surface, or right side surface thereof, or the like, depending on a viewing direction.
[0041] The center part 120 is accommodated inside the housing 110 , and is rotatably disposed. The center part 120 may be connected to an externally disposed motor via pulleys, or may be rotated by a directly connected motor disposed inside the housing 110 .
[0042] Furthermore, at least two protruding keys 121 may be disposed on the outer circumferential surface of the center part 120 . These keys 121 may be integrated with the center part 120 , or may be coupled to the center part 120 by means of a well-known method, such as bolt coupling.
[0043] Furthermore, a guide depression 122 corresponding to a guide protrusion 215 to be described later may be formed in the center part 120 . The tool holder 200 may be stably mounted on the ram spindle 100 by the guide depression 122 and the guide protrusion 215 .
[0044] The first outer part 130 is disposed outside the center part 120 , and is co-rotated with the center part 120 . Outer ribs 131 protruding at equal intervals may be formed on the outer circumferential surface of the first outer part 130 . Although four outer ribs 131 may be formed along the end of the first outer part 130 at equal intervals, as shown in FIG. 3 , the configuration of the outer ribs 131 is not limited thereto.
[0045] In this case, the first outer part 130 and the center part 120 are components separate from each other, and thus key coupling depressions 132 coupled with the keys 121 may be formed in the first outer part 130 so as to receive rotation force when the center part 120 is rotated.
[0046] Furthermore, one or more protrusions 133 formed adjacent to the outer rib 131 may be formed on the first outer part 130 . In other words, the protrusions 133 may be formed on the respective four outer ribs 131 , or a protrusion 133 may be formed on at least any one of the four outer ribs. Depressions 213 to be described later may be inserted over the protrusions 133 , and guide the tool holder 200 to an accurate fastening location with respect to the ram spindle 100 .
[0047] The second outer part 140 may be disposed between the housing 110 and the first outer part 130 , and may be fastened to the housing 110 . In other words, the second outer part 140 supports the center part 120 and the first outer part 130 , surrounding the outer circumferential surface of the center part 120 , inside the housing 110 , and is also fastened to the housing 110 . Accordingly, the second outer part 140 is not rotated even when the center part 120 and the first outer part 130 are rotated.
[0048] Accordingly, a bearing (not shown) may be disposed between the first outer part 130 and the second outer part 140 , and may promote the smooth rotation of the first outer part 130 inside the fastened second outer part 140 .
[0049] Furthermore, a first protrusion and depression part 141 may be formed on the surface of the second outer part 140 , opposite to a coupling part 210 to be described later, so as to be engaged with a second protrusion and depression part 214 formed on the coupling part 210 .
[0050] In other words, when the center part 120 and the first outer part 130 are raised by the actuator unit 150 , the tool holder 200 is firmly fastened to the ram spindle 100 through the engagement between the first protrusion and depression part 141 and the second protrusion and depression part 214 , thereby enabling a rotating base material to be precisely machined.
[0051] The actuator unit 150 may be accommodated inside the housing 110 , may selectively move upward and downward through the open surfaces of the center part 120 and the first outer part 130 , and may be implemented as a pneumatic or hydraulic cylinder.
[0052] Referring to FIG. 5A and FIG. 5B , the actuator unit 150 includes a clamping passage 151 and an unclamping passage 152 , and may further include a spring 153 configured to provide restoring force.
[0053] More specifically, the actuator unit 150 may be disposed inside the center part 120 or first outer part 130 . As shown in FIG. 5A , a hydraulic or pneumatic medium enters into the clamping passage 151 , and raises the lower end of the center part 120 . This raising force may also raise the first outer part 130 coupled through the engagement between the keys 121 and the key depressions.
[0054] In contrast, as shown in FIG. 5B , a hydraulic or pneumatic medium enters into the unclamping passage 152 , and lowers the lower end of the center part 120 . This lowering force may also lower the first outer part 130 coupled through the engagement between the keys 121 and the key depressions.
[0055] Furthermore, since the tool holder 200 needs to be firmly clamped to the ram spindle 100 in order to machine a base material, the spring 153 is preferably disposed to provide restoring force during a shift from an unclamping state to a clamping state.
[0056] Meanwhile, the tool holder 200 may be divided into the coupling part 210 and a mounting part 220 , and the coupling part 210 and the mounting part 220 may be integrated with each other or disposed in a coupled form by using a bolting method.
[0057] The ram spindle 100 is mounted at one end of the coupling part 210 , and the mounting part 220 to be described later is disposed at the other end thereof.
[0058] More specifically, a cavity 211 may be formed at one end, i.e., upper side surface, of the coupling part 210 , and inner ribs 212 protruding to come into contact with the inner diameter of the first outer part 130 or to be spaced apart at predetermined intervals may be formed on the inner circumferential surface of the cavity 211 at equal intervals.
[0059] In this case, the thickness of the upper end defined by the cavity 211 of the coupling part 210 , i.e., the length defined by the inner and outer circumferential surfaces of one end of the coupling part 210 , may be formed to be equal to or smaller than that of the second outer part 140 .
[0060] However, when the coupling between the outer ribs 131 and the inner ribs 212 is taken into account, it is preferred that the outer diameter of the one end of the coupling part 210 is formed to be equal to that of the second outer part 140 and the inner diameter of the one end of the coupling part 210 is formed to be larger than that of the second outer part 140 .
[0061] Furthermore, depressions 213 formed adjacent to the inner ribs 212 and configured to be seated over the protrusions 133 may be formed in the coupling part 210 so as to correspond in number to the protrusions 133 .
[0062] In other words, the inner ribs 212 are made to be disposed at locations where the outer ribs 131 are not formed. When the tool holder 200 is raised and rotated in a clockwise or counterclockwise direction, the depressions 213 and the protrusions 133 are engaged with each other, and thus the accurate disposition location of the tool holder 200 can be determined.
[0063] Furthermore, as described above, the second protrusion and depression part 214 is formed on the upper side surface of the coupling part 210 . When the center part 120 and the first outer part 130 are raised by the actuator unit 150 , the first protrusion and depression part 141 and the second protrusion and depression part 214 are engaged with each other, which enables the tool holder 200 to be firmly mounted on the ram spindle 100 .
[0064] Furthermore, a guide protrusion 215 formed to protrude is formed at the center of the cavity 211 , and is engaged with the guide depression 122 of the center part 120 . Stable coupling is achieved by the guide depression 122 and the guide protrusion 215 .
[0065] At least two inserts 230 may be coupled to the other side, i.e., free end, of the mounting part 220 other than one side of the mounting part 220 coupled to the coupling part 210 . Although a total of four heterogeneous inserts 230 are disposed along an overall region including the opposite side not shown in the drawing, the configuration of the inserts 230 is not limited thereto.
[0066] The tool holder 200 according to the present embodiment may be unclamped from the ram spindle 100 , and may be stored in an auto tool changer (ATC) accommodated inside the ATC accommodation part 6 (see FIG. 1 ).
[0067] In summary, the present invention may be operated as follows. Once a base material is rotated by the turntable 2 (see FIG. 1 ), an unclamping state in which the tool holder 200 is mounted on but not firmly fastened to the ram spindle 100 , as shown in FIG. 5B , is entered in order to bring a programmed insert 230 into contact with the base material.
[0068] Thereafter, the center part 120 is rotated to dispose the insert 230 suitable for an operation in the direction of the base material, and also the first outer part 130 is co-rotated by the center part 120 . The tool holder 200 may be also co-rotated by the rotation of the first outer part 130 .
[0069] When the desired insert 230 is disposed in the direction of the base material, a clamping state is entered, as in the state of FIG. 5A , and thus the first protrusion and depression part 141 and the second protrusion and depression part 214 are firmly engaged with each other, with the result that the tool holder according to the present embodiment is fastened to the ram spindle, thereby enabling a precise turning operation to be performed.
[0070] From the foregoing description, it will be apparent to those skilled in the art that various alterations and modifications may be made without departing from the technical spirit of the present invention. The technical scope of the present invention is not limited to the details described in conjunction with the embodiments, but should be defined by the claims and the ranges equivalent to the claims.
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The present invention relates to a machine tool including a ram spindle and a tool holder, and provides a machine tool comprising: a tool holder including at least two inserts; and a ram spindle capable of fixing the tool holder in a clamped state or rotating the tool holder in order to change the position of the insert, such that the position of the insert can be quickly changed, thereby enabling an improvement in productivity and precision and a reduction in product costs.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to the field of musical instrument improvements and accessories and specifically to flutes.
[0003] 2. Description of the Related Art
[0004] The scale system of the modern Boehm flute has been designed with a focus on accuracy of pitch production as defined through 1) the placement of the tone holes; 2) the size of the tone holes; and 3) the interior diameter and length of tubing upon which the tone holes are placed. These factors are combined in a mathematical schema to arrive at the best compromise of pitch and intonation for each flute.
[0005] The harmonic content of the individual notes may vary widely depending on the variations in schema and the manipulation of different factors in the schema. It is widely accepted that an increase to the overall length of the tubing (or scale length) has the effect of increasing the complexity of the harmonic content of all notes played on the flute while enhancing its resonance and projective capability.
[0006] Scale length is defined as the length of the sounding wave from the cork plate of the headjoint to the cutoff end of the footjoint on any flute. This increase in scale length may be accomplished with the addition of a short length of tubing applied to the bottom end of the footjoint of any existing flute.
[0007] However, when applied to an existing instrument, the scale length addition also has the adverse effect of creating irresolvable intonation problems in the bottom three notes of the scale and an overall degradation of the relationship between the scale tones throughout the sounding range of the flute. This occurs because the mathematical relationship (schema) between the bore (inner dimension), the length of the tube (scale length) and the placement (and size) of the tone holes becomes invalidated by changing one factor without adjusting the others to compensate for that change.
[0008] The subject invention focuses upon increasing the harmonic content of the instrument throughout its full range and increasing the projective capacity of the flute by increasing the length of any existing flute without any of the adverse effects discussed above.
[0009] The subject invention accomplishes this task by adding a carefully defined and proportioned length of tubing to the bottom of the flute tube (footjoint). This length of tubing is designed with a venting system specifically placed to eliminate the adverse effects normally encountered by increasing the length of an existing scale.
BRIEF SUMMARY OF THE INVENTION
[0010] The subject invention encompasses an attachment for a flute comprising an attachable length of tubing; wherein said length of tubing further comprises a first end to be inserted into the footjoint of said flute, wherein the diameter of said first end of said length of tubing is reduced by 0.025 inches from the diameter of said flute footjoint to which said first end of said length of tubing is to be inserted; further wherein said length of tubing further comprises a protruding end not to be inserted in said flute footjoint; wherein said protruding end comprises a major bore diameter that is equal to or slightly exceeds the diameter of said flute; further wherein said protruding end comprises a first and second vent; and wherein said protruding end comprises a length which contains a final air pressure node produced by playing said flute.
[0011] These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. The invention is not limited to the embodiments described herein; thus, reference should be made to the accompanying drawings and descriptive matter in which the preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0012] FIG. 1 illustrates a representation of a cross-sectional view of flute tubing with an opening on both ends; and further illustrates a representation of the variation in air pressure within flute tubing and a representation of the displacement of the air molecules within flute tubing;
[0013] FIG. 2 illustrates the various wavelengths within flute tubing;
[0014] FIG. 3 illustrates an end view of the Foster extension;
[0015] FIG. 4 illustrates a top view of the Foster extension; and,
[0016] FIG. 5 illustrates a side view of the Foster extension.
DETAILED DESCRIPTION OF THE INVENTION
[0017] In order to play the flute, a player blows a rapid jet of air across the embouchure hole. The player accelerates this jet of air by continuously providing power to this jet of air. The power provided by the player to the jet of air is analogous to direct current (DC) electrical power.
[0018] However, the sound produced by the flute from this continuous jet of air requires an oscillating motion of air flow analogous to alternating current (AC) electrical power. In the flute, the jet of air, in cooperation with the resonances in the air within the flute, produces an oscillating component of the air flow. Once the air within the flute is vibrating, some of the energy is radiated as sound out of the end and any open holes of the flute. A much greater amount of energy is lost as a sort of friction with the internal wall of the flute. In a sustained note, this energy is replaced by energy input by the player. The column of air in the flute vibrates much more easily at some frequencies than at others (i.e. it resonates at certain frequencies). These resonances largely determine the playing frequency and thus the pitch, and the player in effect chooses the desired set of resonances by choosing a suitable combination of keys.
[0019] The jet of air from the player's lips travels across the embouchure-hole opening and strikes against the sharp further edge of the embouchure hole. If such a jet of air is disturbed, then a wave-like displacement travels along it and deflects it so that it may flow either into or out of the embouchure hole. The speed of this wave-like displacement on the jet of air is about half the speed of the jet of air (which is typically in the range 20 to 60 meters per second, depending on the air pressure in the player's mouth). The origin of the disturbance of the jet of air is the sound vibration in the flute tube, which causes air to flow into and out of the embouchure hole. If the jet of air speed is carefully matched to the frequency of the note being played, then the jet of air will flow into and out of the embouchure hole at its further edge in just the right phase to reinforce the sound and cause the flute to produce a sustained note.
[0020] A flute is open at both ends. As noted above, although player's lower lip covers part of the embouchure hole, she or he leaves a large part of the hole opening to the atmosphere. In addition, the flute contains an opening at the far end, away from the player. Since a flute is open to the air at both ends, the total pressure at these ends must be atmospheric pressure. In other words, the acoustic pressure, (the variation in pressure within the flute due to sound waves) must be zero. The flute contains specific points called pressure nodes which effectively lie past the end of the flute tubing by a small distance (about 0.6 times the radius). This distance is called the end correction. Inside the flute tubing, the air pressure does not need to be atmospheric. Indeed, in the first resonance the maximum variation in pressure (the pressure anti-node) occurs at the middle.
[0021] The longest standing wave, or fundamental wave, that can satisfy the condition of zero pressure at either end of the flute is twice as long as the flute tubing. The frequency f equals the wave speed v divided by the wavelength λ, so this longest wave corresponds to the lowest note on the flute: C4 on a C foot instrument
[0022] Using the simple calculations shown on FIG. 2 to calculate the frequency played by a flute is only approximately correct. The ‘effective length’ is the value of length that, when substituted into these approximate equations, gives the correct (i.e. measured) frequency. The difference between the ‘effective length’ and the real length of the flute is called the end correction.
[0023] What causes the end correction was first analyzed by John Strutt (a.k.a. Lord Rayleigh). When the air in a flute tubing vibrates in a resonance, it does so along the axis, with maximum vibration at an open end. Just outside the open end is some air that must be pushed forward and backwards by the vibration of air inside the flute tubing. That air has mass and inertia, and its that inertia that lowers the pitch of the flute. Outside the flute tubing, the sound wave radiates in nearly all directions, so the further you go from the open end, the less the effect and only air very near to the open ends of the flute tubing is involved. This air outside the open ends of the flute tubing make the flute tubing effectively longer than it really is. For a simple open pipe, the extra length is about 0.6 times its radius.
[0024] End corrections are more complicated in real instruments. The end correction at the foot of a flute for the lowest note of the instrument is indeed about 0.6 times its radius. For the flute, the tubing is open at both ends, but a player can vary the embouchure hole opening by rolling it towards themselves (which makes a longer end effect—the note goes flat) or away (conversely). There is also the small volume of air between the embouchure hole and the cork. Finally, if we consider a woodwind instrument with several open tone holes, it is not just the air outside the first tone hole that must be vibrated, but air inside the bore, too. So the end correction is longer here.
[0025] What is missing from the design of the flute is a mechanism that captures and focuses this aspect of wave formation. The tradition of flute making has involved an empirical derivation of tubing length and tone hole placement which has been passed through the generations of craftsmen. The focus of this empirical work has always been to define a length of tubing that would most accurately produce a given pitch.
[0026] This invention of the subject application goes a step beyond these computations to create an in-depth, comprehensive method of strengthening the projective and resonant capabilities of the instrument without tampering with the pitch.
[0027] As shown in FIG. 1 , straight lines represent a cross-sectional view of flute tubing 1 with openings 2 and 3 on either end of the flute. A player blows a jet of air across the embouchure hole into this flute tubing 1 . The lines 4 represent the variation in air pressure within the flute tubing 1 along the same length of flute tubing 1 . Pressure anti-node 6 of lines 4 indicates the maximum variation in pressure in this resonance. Pressure node 7 indicates the minimum variation in pressure in this resonance. The lines 5 represent the variation in the displacement of the air molecules within the flute tubing 1 along the same length of flute tubing 1 . The lines 5 has displacement anti-node 8 at the ends since air molecules are free to move in and out at the open ends of the flute tubing 1 .
[0028] As noted above, flute tubing 1 is open at both ends, openings 2 and 3 . Although a player's lower lip covers part of the embouchure hole, she or he leaves a large part of the hole open to the atmosphere. Since a flute is open to the air at both ends, the total pressure at these ends must be atmospheric pressure or the acoustic pressure, (the variation in pressure within the flute due to sound waves) must be zero.
[0029] FIG. 2 illustrates the longest standing wave, or fundamental wave 9 , that can satisfy the condition of zero pressure at either end of the flute tubing 1 . FIG. 1 illustrates one half of the fundamental wave 9 with lines 4 . Thus, FIG. 2 shows that this fundamental wave 9 has a wavelength that is twice as long as flute tubing 1 . The frequency f equals the wave speed v divided by the wavelength λ, so this longest wave corresponds to the lowest note on the flute: C4 on a C foot instrument
[0030] The equations for determining frequency are:
[0000] λ=2 L
[0000] f=v/λ=v/ 2 L=f 0
[0000] Wherein λ=wavelength; f=frequency; v=wave speed; L=length of flute tubing; and f 0 =fundamental frequency.
[0031] FIG. 2 illustrates the wavelength λ for the fundamental frequency 9 ; the wavelength λ for the second harmonic 10 ; the wavelength λ for the third harmonic 11 ; the wavelength λ for the fourth harmonic 12 ; the wavelength λ for the fifth harmonic 13 ; and the wavelength λ for the sixth harmonic 14 .
[0032] The above calculations are only approximately correct in calculating the frequency played by a flute. The ‘effective length’ is the value of length that, when substituted into these approximate equations, gives the correct (i.e. measured) frequency. The difference between the ‘effective length’ and the real length of the flute is called the end correction.
[0033] For example, if a pipe that is 170 millimeters long and sealed at one end is played until the pipe resonates or produces its own strong vibration. To calculate the frequency of this vibration, (supposing that temperature and humidity are such that the speed of sound is 340 meters/second) the lowest resonance should have a wavelength about 4 times longer than the closed pipe since the pipe is closed at one end like a clarinet. If the pipe had been open at both ends, like a flute, that the lowest resonance should have a wavelength that is twice the length of the open pipe. Now 4 multiplied by 170 millimeters is a wavelength of 680 millimeters or 0.68 meters. Thus, according to this sample calculation, the frequency of this lowest resonance, which is speed of sound divided by wavelength, should be approximately 340 meters/second divided by 0.68 meters=500 Hertz. Similarly, if this pipe had been open at both ends the wavelength would be 2 multiplied by 170 millimeters to equal 0.34 meters with a calculated frequency of 1000 Hz.
[0034] However, the measured frequency is slightly lower than what is calculated, and the larger the diameter of the pipe, the larger the depression of the pitch. The pipe produces a wavelength as though it were a little longer than it really is. Now the effective length is the length that would give me exactly the measured frequency. Thus, as we said above, the effective length minus the real length is called the end correction. For the open pipe, there will be two end corrections, one for each open end. The end correction at the foot of a flute for the lowest note of the instrument is indeed about 0.6 times its radius.
[0035] This invention compensates for the absence of balance in tone production by creating a chamber for the bottom end of the wave from which closely resembles the top end. The result is a more balanced wave from which captures energy which would normally be lost through atmospheric dissipation (as it extends beyond the end of the normal flute tube). This invention provides the player with a device with which to manipulate the timbre and dynamic range of the modern flute in an entirely heretofore unseen degree.
[0036] FIG. 3 illustrates an end view of the Foster Extension. The larger diameter tubing and the smaller (tenon) tubing which is inserted in the flute footjoint are shown. FIG. 3 also illustrates the unique vent hole configuration 17 which has a surface concentric to the radius of the major outer diameter of the 0.81 inch diameter tubing surface 23 . Further the 0.5 inch end of said length of tubing comprises an internal diameter 24 of 0.72 inches and an external diameter 25 of 0.74 inches. The said first end of said length of tubing comprises a length of 0.5 inches. The non-inserted protruding 2 inch second end of said length of tubing comprises an internal diameter 26 of 0.747 inches and an external diameter 27 of 0.775 inches. The non-inserted protruding second end of said length of tubing may comprise a length of 2 inches and the first vent hole and said second vent hole 28 comprise an internal diameter of 0.69 inches.
[0037] FIG. 4 illustrates the top view of the Foster Extension. The vent hole 17 shown represents one of two which are constructed directly opposite each other on the outside circumference of the tubing 18 . This design requires two different diameters of tubing contiguous to a single length. The smaller diameter length 19 is intended to be inserted into the footjoint end of the flute and is required only as a mechanism to keep the attachment in place. There are two vent openings 17 which are tangent to the end of the tubing and are intended to allow the end of the existing flute tube to define the length of the wave form without dampening or flattening the pitch. The remaining tubing 20 serves to capture the node of the wave which would normally fall outside the end of the flute tubing (end correction).
[0038] FIG. 5 illustrates the side view of the Foster Extension. The two vent holes 17 shown on the top 21 and the bottom 22 of the Foster extension are constructed directly opposite each other on the outside circumference of the tubing 18 . This design requires two different diameters of tubing contiguous to a single length. The smaller diameter length 19 is intended to be inserted into the footjoint end of the flute and is required only as a mechanism to keep the attachment in place. There are two vent openings 17 which are tangent to the end of the tubing and are intended to allow the end of the existing flute tube to define the length of the wave form without dampening or flattening the pitch. The remaining tubing 20 serves to capture the node of the wave which would normally fall outside the end of the flute tubing (end correction). Further, the diameter measurement 23 between the two vent openings 17 will be 0.81 inch.
[0039] In one embodiment of the subject invention, the foster extension is manufactured from a piece of metal tubing having the overall length of 3 inches and an inside diameter of 0.747 inches. This piece of metal tubing is mounted upon a reducing mandrel. Approximately 0.75 inches of the length of this metal tubing is spun down in a lathe fixture until it has been reduced to by approximately 0.25 inches in length. This forms the tenon, or connecting piece, which will be inserted into the bottom of the footjoint section of the flute.
[0040] Two toneholes are located on opposite sides of the remaining part of the tubing with the outside surface of their radius flush with the point at which the reduced section of the tubing begins. This functions as a venting schema which allows the air column to effectively “see” the original cutoff point as the end of the tube (in terms of pitch).
[0041] The extension of the subject invention may be constructed from any material capable of retaining the required dimensions without distortion, including, but not limited to: precious metal of any alloy, wood, ceramic, glass and crystal. The extension of the instant invention is intended for use on flutes constructed of any material, including, but not limited to: precious metal of any alloy, wood, ceramic, glass and crystal.
[0042] The subject invention is designed and constructed to be a portable and removable attachment to be used with any existing flute which will improve both the harmonic content (timbrel complexity) and the projective capability of any scale design.
[0043] The instant invention may be applied to any pitched flute of any dimensions and encompasses the full range of flute sizes and any variation in pitch or scale design including, but not restricted to: C flute, G (alto) flute and C Bass flute. It is also designed to work on piccolos of any pitch or construction.
[0044] The instant invention further illustrates a method of strengthening the projective and resonant capabilities of an instrument, without altering the pitch. This method comprises reducing the diameter of a first end of a length of tubing by 0.025 inches from the diameter of a flute footjoint to which said first end of said length of tubing is to be inserted, inserting said first end of said length of tubing length into said flute footjoint, attaching said length of tubing to said flute footjoint, supplying said length of tubing with a non-inserted protruding second end wherein said non-inserted protruding second end comprises a major bore diameter that is equal to or slightly exceeds the diameter of said flute, supplying said non-inserted protruding second end with a first and second vent, and supplying said non-inserted protruding second end with a length which contains a final air pressure node.
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A flute attachment which improves and enhances the harmonic capability of a flute by lengthening the resonant chamber of the standing wave. The instant invention ‘fine tunes’ the harmonic range of the flute by taking into account the end point of the fundamental length of the sounding oscillations of an air column without negating the frequency which has been predetermined by the original terminus of the physical scale length of the flute. The sound wave length within a flute terminates slightly beyond the physical length of the flute tube and this difference in length is known as the ‘end correction’. The instant invention captures the node which extends beyond the flute tubing and balances and reinforces the propagation of upper partials throughout the sounding range of the instrument.
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RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application Ser. No. 60/569,952, filed May 11, 2004 (pending) and U.S. Provisional Application Ser. No. 60/571,553, filed May 13, 2004, (pending), the disclosures of which are hereby incorporated by reference herein in their entireties.
BACKGROUND OF THE INVENTION
[0002] The invention relates to the treatment of autoimmune disorders.
[0003] Gastrointestinal microflora play a number of vital roles in maintaining gastrointestinal tract function and overall physiological health. Perturbations in gastrointestinal function are associated with the onset and progression of immune system disorders, including autoimmune disorders. Autoimmune disorders develop when the immune system mounts an immune response against normal body tissues. Normally, the immune system is capable of differentiating “self” from “non-self” tissue. Autoimmune disorders occur when the normal control process is disrupted. They may also occur if normal body tissue is altered so that it is no longer recognized as “self.” Microorganisms, such as pathogenic bacteria, fungi, and viruses, and other causes (drugs, alcohol, smoking, stress) trigger some of these changes, particularly in people with a genetic predisposition to an autoimmune disorder. Autoimmune disorders result in destruction of one or more types of body tissues, abnormal growth of an organ, or changes in organ function. The disorder may affect only one organ or tissue type or may affect multiple organs and tissues. Organs and tissues commonly affected by autoimmune disorders include blood components such as red blood cells, blood vessels, connective tissues, endocrine glands such as the thyroid or pancreas, muscles, joints, and skin.
[0004] Psoriasis is a chronic, genetically-influenced autoimmune disorder, most common in people in their 20s, 30s, and 40s. Psoriasis is rare under age 3. In the United States, two or three out of every 100 people suffer from psoriasis. Current topical psoriasis treatments use emollients, keratolytic agents, coal tar, anthralin, corticosteroids, and calpotriene. These approaches have variable efficacy, fail to prevent frequent relapses, and are often associated with adverse side effects. Current systemic treatments are usually reserved for patients with physically, socially, or economically disabling psoriasis that has not responded to topical treatment, and often include phototherapy and/or antifungal drugs, the latter of which can only be used for short periods of time due to toxicity and adverse side effects. Accordingly, there is a need for an effective systemic psoriasis treatment that avoids the disadvantages associated with current topical and systemic treatments.
SUMMARY OF THE INVENTION
[0005] The invention provides a method of reducing a symptom of psoriasis by identifying a patient suffering from or at risk of developing psoriasis and administering to the patient a composition that includes Bacillus coagulans bacteria. The composition is ingested by a human subject that has one or more symptoms of a dermatological disorder such as psoriasis. Bacterial species include Bacillus coagulans , e.g., Bacillus coagulans hammer, preferably Bacillus coagulans hammer strain Accession No. ATCC 31284, or one or more strains derived from Bacillus coagulans hammer strain Accession No. ATCC 31284 (e.g., ATCC Numbers: GBI-20, ATCC Designation Number PTA-6085; GBI-30, ATCC Designation Number PTA-6086; and GBI-40, ATCC Designation Number PTA-6087; see U.S. Pat. No. 6,849,256 to Farmer). Symptoms of psoriasis include scaling, blistering, skin lesions, itchiness, and pain (e.g., joint pain). In embodiments of the invention, the composition also includes a non-microbially derived antifungal agent (e.g., a member of the azole or pyrrole class of antifungal compounds such as clotrimazole, fluconazole, itraconazole, ketoconazole, miconazole, nystatin, terbinafine, terconazole, or tioconazole), an immunosuppressive agent (e.g., methotrexate, tacrolimus, cyclosporine, hydroxyurea, mycophenolate mofetil, sulfasalazine, or 6-thioguanine), a retinoid, or an antibiotic agent (e.g., gentamicin, vancomycin, oxacillin, tetracycline, nitroflurantoin, chloramphenicol, clindamycin, trimethoprim sulfamethoxasole, cefaclor, cefadroxil, cefixime, cefprozil, ceftriaxone, cefuroxime, cephalexin, loracarbef, ampicillin, amoxicillin clavulanate, bacampicillin, cloxicillin, penicillin VK, ciprofloxacin, grepafloxacin, levofloxacin, lomefloxacin, norfloxacin, ofloxacin, sparfloxacin, trovafloxacin, azithromycin, or rythromycin). Administration to the patient includes delivery of the composition(s) via the gastrointestinal tract. The gastrointestinal tract is the system of organs in a mammal including the mouth (buccal cavity), pharynx, esophagus and cardia, stomach(s), and intestines. The bacteria are administered at a dose that reduces a level of TNF-α in the patient.
[0006] Following oral administration, colonization of the gastrointestinal tract with Bacillus coagulans bacteria occurs between 24-48 hours. Continued colonization is improved by the repeated administration of Bacillus coagulans , such as daily administration. For example, a Bacillus coagulans bacteria-containing composition is administered (e.g., taken orally) about once every day for about 2, 3, 4, 5, 6, 7, 10, 15, 20, 25, 30, 45, 60, 75, 90, 100, 125 or more days. In embodiments of the invention the Bacillus coagulans bacteria are provided at a concentration of from about 1×10 8 to about 1×10 10 viable bacteria, e.g., at a concentration of from about 1×10 9 to about 2×10 9 viable bacteria. The Bacillus coagulans bacteria are provided in the form of spores and/or vegetative cells.
[0007] The invention also provides a method for the treatment of psoriasis by administering a first dose of a composition containing Bacillus coagulans bacteria at a first point in time, and administering a second dose of the composition at a second, subsequent point in time. The bacteria are, for example, Bacillus coagulans hammer or bacteria derived from Bacillus coagulans hammer strain Accession No. ATCC 31284. The treatment includes treating a symptom of psoriasis (e.g., scaling, blistering, skin lesions, itchiness, and joint pain). Bacillus coagulans bacteria are provided at a concentration of from about 1×10 8 to about 1×10 10 viable bacteria, e.g., at a concentration of from about 1×10 9 to about 2×10 9 viable bacteria. The Bacillus coagulans bacteria are provided in the form of spores or vegetative cells. The composition includes a non-microbially derived antifungal agent, such as an azole, an organic five-membered ring compound containing one or more atoms in the ring. Exemplary azoles include clotrimazole, fluconazole, itraconazole, ketoconazole, miconazole, nystatin, terbinafine, terconazole, or tioconazole. The invention optionally includes administration of an immunosuppressive agent, such as methotrexate, cyclosporine, hydroxyurea, mycophenolate mofetil, sulfasalazine, or 6-thioguanine, or an antibiotic agent, such as gentamicin, vancomycin, oxacillin, tetracycline, nitroflurantoin, chloramphenicol, clindamycin, trimethoprim sulfamethoxasole, cefaclor, cefadroxil, cefixime, cefprozil, ceftriaxone, cefuroxime, cephalexin, loracarbef, ampicillin, amoxicillin clavulanate, bacampicillin, cloxicillin, penicillin VK, ciprofloxacin, grepafloxacin, levofloxacin, lomefloxacin, norfloxacin, ofloxacin, sparfloxacin, trovafloxacin, azithromycin, and rythromycin. The bacteria, antifungal compound(s), and immunosuppressive compound(s) are administered concurrently or sequentially.
[0008] The invention also provides a method of reducing a symptom of an autoimmune disorder by identifying a patient suffering from or at risk of developing an autoimmune disorder, and administering to the patient a composition including Bacillus coagulans bacteria. The autoimmune disorder is psoriasis, Crohn's Disease, colitis, lupus, arthritis, or any other disorder that is characterized by a pathological increase in activation of immune cells (e.g., T cells) associated with a pathogenic agent (such as a bacteria, fungus or virus).
[0009] The invention further provides a method for decreasing a symptom of an autoimmune disorder in a mammal affected thereby, by administering to a mammal a composition that includes Bacillus coagulans bacteria. A symptom (e.g., scaling, blistering, skin lesions, itchiness, and/or pain) of the autoimmune disorder is decreased following the administration, compared to the severity of the symptom prior to the administration.
[0010] The invention also provides a method for decreasing serum TNF-α or other cytokine levels in a mammal that has been diagnosed with an elevated level of TNF-α, or one or more other cytokines. Normal human serum levels of TNFα range from undetectable to about 40 pg/ml of serum, with average values in the range of 3-10 pg/ml. TNF-α is preferably detected by, e.g., ELISA or other quantitative detection means. (Human TNF-α ELISA kit, Abazyme, Needham, Mass., or Millenia Diagnostic Product, Los Angeles, Calif.).
[0011] Serum cytokine levels (such as TNF-α levels) are decreased following the administration of Bacillus coagulans , when compared to serum cytokine (such as TNF-α) levels in the mammal prior to the administration. Elevated human serum levels (e.g., greater than about 40, 50, 60, 75, 85, 100, 125, 150, 200, 250, 300, or more pg/ml) prior to administration are associated with autoimmune disorders, and are reduced following a course of administration of Bacillus coagulans . A reduction in TNF-α levels confers a clinical benefit to the treated subject, e.g., a reduction in a symptom of an autoimmune disorder. The decrease is any measurable decrease, such as a decrease greater than about 1%, 5%, 10%, 15%, 25%, 50%, 60%, 75%, 85%, 90%, 95%, 99%, 99.9%, 99.99% or greater. The Bacillus coagulans bacteria are provided at a concentration of from about 1×10 8 to about 1×10 10 viable bacteria, such as 5×10 8 , 8×10 8 , 1×10 9 , or 5×10 9 viable bacteria.
[0012] The invention further provides a composition that includes a Bacillus coagulans bacterium, and an immunosuppressive agent. The composition is in the form of a capsule, tablet, powder, or liquid. The Bacillus coagulans bacteria can be Bacillus coagulans hammer or derived from Bacillus coagulans hammer, e.g., Bacillus coagulans hammer strain Accession No. ATCC 31284.
[0013] The invention also provides a system containing medical food for the management of psoriasis or other disorder that includes Bacillus coagulans bacteria, where the medical food is formulated to provide at least about 1×10 6 viable Bacillus coagulans bacteria in the gastrointestinal tract of a mammal per day, based on a serving size of about 1 gram to about 2 grams of the medical food taken up to about twice a day, and instructions for use thereof. In embodiments of the invention, the medical food optionally includes a non-microbially derived anti-fungal agent, an immunosuppressive agent, or a non-microbially derived anti-fungal agent and an immunosuppressive agent.
[0014] Other features and advantages of the invention will be apparent from the following detailed description and from the claims.
DETAILED DESCRIPTION
[0015] The mammalian gastrointestinal tract is a complex ecosystem host to a diverse and highly evolved microbial community composed of hundreds of different microbial species. A perturbation of the interactions that occur between this complex microbial community and the mammal can lead to diseases such as illnesses associated with deficient or compromised microflora (e.g., gastrointestinal tract infections, inflammatory bowel diseases (such as Crohn's disease and ulcerative colitis), irritable bowel syndrome, antibiotic-induced diarrhea, constipation, food allergies, cardiovascular disease, psoriasis, and certain cancers. “Functional food,” e.g., those that contain beneficial bacteria such as Bacillus coagulans are useful as therapies to prevent autoimmune diseases and other diseases characterized by an increase in TNF-α compared to normal, control levels.
[0016] Lactic acid bacteria (LAB) display numerous health benefits beyond providing general digestive value. They cooperatively maintain a physiological balance between the gastrointestinal tract and immune system. When this balance is disrupted, disease and inflammation often result. Deleterious bacteria are competitively inhibited by the mucosal adherence or transient colonization of beneficial microflora such as Bacillus coagulans . A healthy gastrointestinal tract with adequate mucus production and appropriate bacterial colonization prevents or inhibits the growth of pathogenic or opportunistic microorganisms, modulates disease processes, and prevents widespread inflammatory disorders.
[0017] Bacillus coagulans is an L+ lactic acid-producing bacterium that has been shown to be highly effective in the colonization of the various mucosal surfaces of the gastrointestinal tract. Unlike strictly vegetative species of lactic acid bacteria (e.g., Lactobacillus, Bifidobacterium , and other bacteria) that are used in therapeutic applications, Bacillus coagulans survives intact after exposure to extremely low pH of stomach and bile acids. This is accomplished due to the extremophile nature of the vegetative form of this organism (thermo-tolerant, acidophilic, baro-tolerant, and halo-tolerant), and that it forms endospores. In addition, Bacillus coagulans is highly competitive, which is an important feature for the high-density colonization that is required to promote physiological changes in the small and large bowel. Further, Bacillus coagulans has been shown in Minimum Inhibitory Concentration (MIC) dilution (in vitro) studies to inhibit many enteric bacterial pathogens ( Escherichia, Proteus, Clostridium, Campylobacter, Shigella, Salmonella, Enterococcus, Staphylococcus, Streptococcus , and others), which require a higher than neutral pH in order to proliferate. MIC studies have also been performed that indicate high inhibitory activity on various mycotic pathogens challenged with Bacillus coagulans.
[0018] The methods and compositions of the present invention are useful in the treatment of autoimmune diseases. Autoimmune diseases can affect almost any organ or tissue of the body, and are thus amenable to classification by the affected tissue(s). It is recognized that an autoimmune disease or disorder can impact one or more tissues. Autoimmune disorders that affect the blood or vasculature including autoimmune hemolytic anemia, pernicious anemia, polyarteritis nodosa, systemic lupus erythematosus, and Wegener's granulomatosis. Autoimmune disorders of the gastrointestinal system include autoimmune hepatitis, Behçet's disease, Crohn's disease, primary biliary cirrhosis, scleroderma, ulcerative colitis, and Irritable Bowel Syndrome (IBS). Autoimmune disorders that affect the ocular system include Sjögren's syndrome, type 1 diabetes mellitus, and uveitis. Autoimmune disorders that affect the endocrine system include Graves' disease, and thyroiditis. Autoimmune disorders that affect the cardiovascular system include myocarditis, rheumatic fever, scleroderma, and systemic lupus erythematosus. Autoimmune disorders that affect connective tissue include ankylosing spondylitis, rheumatoid and reactive arthritis, and systemic lupus erythematosus. An autoimmune disorder that affects the kidneys is glomerulonephritis. An autoimmune disorder that affects the lungs is glomerulonephritis is sarcoidosis. Autoimmune disorders that affect the musculoskeletal system include dermatomyositis, myasthenia gravis, polymyositis, and fibromialgia. Autoimmune disorders that affect the neurological system include Guillain-Barré syndrome, and multiple sclerosis. Autoimmune disorders that affect the skin include alopecia areata, pemphigus (also termed pemphigoids), psoriasis, and vitiligo.
[0019] Symptoms of autoimmune disease include fatigue, dizziness, malaise, fever, and decreased platelet and/or eosinophil counts. Further, certain autoimmune diseases are characterized by destruction of a type of tissue (e.g., destruction of islet cells of the pancreas in diabetes) or the increase in organ size (e.g., thyroid enlargement in Graves Disease). For treatment or prevention of such diseases or conditions and reduction of symptoms associated with these conditions, compositions that contain Bacillus coagulans bacteria are administered according to the methods described herein.
[0020] TNF-α is a naturally occurring cytokine, which is produced by activated immune cells. However, excessive activation of immune effector cells and overproduction of TNF-α can cause severe inflammation and tissue damage. TNF-α plays a major role in a number of disease states, e.g., psoriasis, Crohn's disease, rheumatoid arthritis, ulcerative colitis, and ankylosing spondylitis. Reducing the level of TNF-α in patients suffering from or at risk of developing autoimmune disease or inflammatory disease states alleviates symptoms of the disease and prevents or slows disease progression.
[0021] Reducing TNF-α by administering Bacillus coagulans confers a clinical benefit (e.g., reduced inflammation) with little or none of the side effects associated with other, non-microbial TNF-α inhibitors (e.g., infliximab, etanercept, and adalimumab). Administration of Bacillus coagulans confers a clinical benefit to subjects identified as suffering from or at risk of developing the following exemplary autoimmune disorders.
Psoriasis
[0022] Psoriasis is a skin disease that is characterized in part by abnormal proliferation and differentiation of keratinocytes, T-cell and endothelial cell activation, local vascular changes, and neutrophil accumulation as well as other immunological processes, e.g., altered levels of cytokines. Results of cyclosporine and fluconazole treatments also demonstrate that bacterial and mycotic agents play a significant role in psoriasis.
[0023] Psoriasis generally results from a genetic defect in combination with external triggers that affect the features of the disease. The cellular immune system plays a dominant role in exacerbation of psoriasis. Microorganisms such as β-hemolytic streptococci, Staphylococcus aureus and Candida albicans are external triggers that release factors which serve as superantigens, and stimulate the T cells to initiate psoriasis, which often resulting in a “pathogenic circle” of repeated incidences of the disease. The source of the microorganisms may be in the skin itself or in distal locations, such as Streptococcus in the throat or Candida albicans in the gut. From these locations, the microorganisms cause the release of superantigens that travel through the host's vascular system to reach the skin and initiate the psoriatic process.
[0024] There are many different forms of psoriasis, including plaque psoriasis (vulgaris psoriasis), guttate psoriasis, pustular psoriasis, erythrodermic psoriasis, nail psoriasis, scalp psoriasis, inverse psoriasis, and psoriatic arthritis. Symptoms of psoriasis vary among the forms of psoriasis, and between affected individuals. As used herein, a “symptom” of psoriasis includes any observable, measurable or detectable sign or indication of any form of psoriasis or a psoriasis-related condition. A patient suffering from psoriasis has one or more symptoms of psoriasis. Psoriasis symptoms include scaling, blistering, skin lesions, itchiness, and joint pain. Other symptoms of psoriasis are known to those of ordinary skill in the art. Psoriasis is diagnosed by the observation or detection of one or more symptoms of psoriasis. Generally, a patient suffering from or at risk of developing psoriasis has one or more symptoms of psoriasis, or a family member having psoriasis or a symptom of psoriasis.
[0025] Indications of treatment of psoriasis include any detectable change (e.g., a decrease or disappearance) in a symptom of psoriasis, as measured by size, severity, duration, or the presence or absence of relapses of affected skin. A preferred method of determining the efficacy of a treatment is the measurement of the change in the total psoriatic lesion area following Bacillus coagulans treatment, as compared to the in total psoriatic lesion area prior to treatment. Also, a measurable decrease in the amount of serum TNF-α in a patient undergoing psoriasis treatment indicates the efficacy of the treatment. Further, the efficacy of treatment can be determined by the decrease in pathogenic microorganisms present in the gastrointestinal tract of the patient undergoing treatment, such as by measuring the presence of these microorganisms in stool measurement in stool or other biological materials.
Inflammatory Bowel Disease
[0026] Human inflammatory bowel disease (IBD) is a group of intestinal inflammatory diseases that can be subdivided in ulcerative colitis (UC) and Crohn's disease (CD) based on typical clinical manifestations. The symptoms of both are extremely unpleasant and impact all aspects of quality of life. They include diarrhea, abdominal pain, rectal bleeding, fever, nausea, weight loss, lethargy and loss of appetite. If left untreated, malnutrition, dehydration and anemia follow, which, in extreme cases, lead to death. Although UC and CD show a considerable degree of similarity in etiology and epidemiology, they are entirely different in pathology. UC is restricted to the colon. CD, however, has been observed throughout the entire intestinal tract, from the mouth to the rectum. Inflammation is restricted to the mucosa in UC, whereas in CD the inflammation can be transmural, i.e., penetrating the bowel wall. This often leads to the development of perianal fistulae. An imbalance in T-helper (Th) subsets of T cells, so called Th1 and Th2, differentiates CD from UC on an immunological basis. In UC, an over-expression of Th2 type cytokines (IL-4, IL-5) has been demonstrated, whereas in CD, Th1 type cytokines (IL-12, IFN-γ) predominate.
[0027] CD and UC involve an interaction between genetic and environmental factors, such as bacterial agents. Abnormal immune responses, driven by the intestinal microflora, occur in IBD. Most experimental models for IBD cannot be established in germ-free animals. In one art-recognized experimental model, IL-10−/− mice show that the appearance of mucosal adherent colonic bacteria is causative of the development and maintenance of the inflammation.
[0028] Breach of tolerance towards normal intestinal microflora may thus be the driving force behind IBD. The absence of tolerance to the indigenous microflora also appears in trinitrobenzene sulphonic acid (TNBS)-induced colitis. The administration of IL-10, a central mediator in down-regulation of immune reactions, restores healthy status by reestablishing tolerance. This treatment does not, however, affect immune reactivity towards heterologous bacterial antigen. Staphylococcal enterotoxin B can abrogate self-tolerance at the intestinal epithelium. IL-10 can counteract this by preventing the activation of T cells that contribute to epithelial cell damage. T-cell clones stimulated by indigenous aerobic flora and bifidobacteria were also identified in patients with IBD.
[0029] Higher bacterial load has been reported in the mucus of IBD patients. Although a number of reports measure no significant differences in the flora composition of UC patients when compared with controls, two recent studies indicate significant decrease of lactobacilli in UC. There are conflicting reports on the composition of the microflora in CD although it is difficult to compare disease stages when assessed in different centers. Bifidobacterium species are found to be decreased in CD. A significant increase in Escherichia coli and Bacteroides fragilis was detected in the ileum and of E. coli and lactobacilli in the colon, although lactobacilli, together with bifidobacterial scores, have also been found significantly reduced in CD patients.
[0030] The development of IBD is in some cases linked to viral or bacterial infection ( Mycobacteria, Shigella, Salmonella, Yersinia, Clostridium difficile, Bacteroides vulgatus ) but to date no etiological agent has been identified for IBD. Recently, however, a DNA sequence has been identified in lamina propria mononuclear cells of which the presence and serum reactivity towards the according peptide highly correlates with CD. This presently unknown sequence is not of human origin and shows homology with bacterial tetR/acrR transcription regulators.
Systemic Lupus Erythematosus (SLE)
[0031] An inflammation of the connective tissues, SLE impacts one or more organs or tissues in a subject. It is up to nine times more common in women than men. Further, SLE impacts black women three times as often as Caucasian women. The condition is aggravated by sunlight. Symptoms include fever, weight loss, hair loss, mouth and nose sores, malaise, fatigue, seizures and symptoms of mental illness. Identification of a patient suffering SLE from is accomplished by identifying one or more of these symptoms in the patient. Ninety percent of patients experience joint inflammation similar to rheumatoid arthritis. Fifty percent develop a classic “butterfly” rash on the nose and cheeks. Raynaud's phenomenon (extreme sensitivity to cold in the hands and feet) appears in about 20 percent of people with SLE. Current treatments are limited to the use of anti-inflammatory drugs to control arthritis symptoms, and topical steroidal creams to treat skin lesions, while oral steroids, such as prednisone, are used for the systemic symptoms. One or more symptoms of SLE are reduced following treatment with Bacillus coagulans bacteria.
Rheumatoid Arthritis
[0032] Rheumatoid arthritis is a systemic disorder in which immune cells attack and inflame the membrane around joints. It also can affect the heart, lungs, and eyes. Of the estimated 2.1 million Americans with rheumatoid arthritis, approximately 1.5 million (71 percent) are women. Symptoms of the disease include inflamed and/or deformed joints, loss of strength, swelling, and pain. Identification of a patient suffering from rheumatoid arthritis is accomplished by identifying one or more of these symptoms in the patient. Current treatment modalities include rest and anti-inflammatory drugs. One or more symptoms of rheumatoid arthritis are reduced following treatment with Bacillus coagulans bacteria.
Scleroderma (Systemic Sclerosis)
[0033] Scleroderma involves the hyperactivity of certain immune cells, which produce fibrous, scar-like tissue in the skin, internal organs, and small blood vessels. It affects women three times more often than men overall, but increases to a rate 15 times greater for women during childbearing years, and appears to be more common among black women than Caucasian women. Symptoms of scleroderma include the appearance of Raynaud's phenomenon, as well as swelling and puffiness of the fingers or hands. Often, skin thickening follows, and other symptoms include skin ulcers on the fingers, joint stiffness in the hands, pain, sore throat, and diarrhea. Identification of a patient suffering from scleroderma is accomplished by identifying one or more of these symptoms in the patient. Current treatments of scleroderma include D-penicillamine, which has been shown to decrease skin thickening. This disorder also impacts other organs such as the kidneys, esophagus, intestines, and blood vessels and thus requires multi-system treatments. One or more symptoms of scleroderma are reduced following treatment with Bacillus coagulans bacteria.
Sjogren's Syndrome
[0034] Sjögren's syndrome (also called Sjögren's disease) is a chronic, slowly progressing inability to secrete saliva or tears. It can occur alone or with rheumatoid arthritis, scleroderma, or systemic lupus erythematosus. Nine out of 10 cases occur in women, most often at or around mid-life. Symptoms of this disorder include dryness of the eyes and mouth, swollen neck glands, difficulty swallowing or talking, unusual tastes or smells, thirst, tongue ulcers, or severe dental caries. Identification of a patient suffering from Sjögren's syndrome is accomplished by identifying one or more of these symptoms in the patient. Current treatments include interventions to keep the mouth and eyes moist (including drinking a lot of fluids and using eye drops, as well as good oral hygiene and eye care). One or more symptoms of Sjögren's syndrome are reduced following treatment with Bacillus coagulans bacteria.
Multiple Sclerosis (MS)
[0035] Multiple sclerosis is a disease of the central nervous system that usually first appears between the ages of 20 and 40; it affects women twice as often as men. MS is the leading cause of disability among young adults. MS is recognized to be an unpredictable disease of the central nervous system, and can range from relatively benign to somewhat disabling to devastating, as communication between the brain and other parts of the body is disrupted. Symptoms of MS include fatigue, problems walking, bowel and/or bladder disturbances, visual problems, changes in cognitive function, including problems with memory, attention, and problem-solving, abnormal sensations such as numbness or “pins and needles,” changes in sexual function, pain, depression and/or mood swings, tremor, speech and swallowing problems, and impaired hearing. Identification of a patient suffering from multiple sclerosis is accomplished by identifying one or more of these symptoms in the patient. The vast majority of patients are mildly affected, but in the worst cases MS can render a person unable to write, speak, or walk. One or more symptoms of MS are reduced following treatment with Bacillus coagulans bacteria.
Myasthenia Gravis
[0036] Myasthenia gravis is a chronic autoimmune disorder characterized by gradual muscle weakness, often appearing first in the subject's face and often characterized by drooping eyelids, as well as double vision, difficulty breathing, talking, chewing, and swallowing. Identification of a patient suffering from myasthenia gravis is accomplished by identifying one or more of these symptoms in the patient. The drug edrophonium is currently used as a treatment, along with daily rest periods, which can improve muscle strength. One or more symptoms of myasthenia gravis are reduced following treatment with Bacillus coagulans bacteria.
Guillain-Barre Syndrome
[0037] Guillain-Barré syndrome is a disorder in which the body's immune system attacks part of the peripheral nervous system. The first symptoms of this disorder include varying degrees of weakness or tingling sensations in the legs. Identification of a patient suffering from Guillain-Barré syndrome is accomplished by identifying one or more of these symptoms in the patient. In many instances, the weakness and abnormal sensations spread to the arms and upper body. These symptoms can increase in intensity until the muscles cannot be used at all and the patient is almost totally paralyzed. In these cases, the disorder is life threatening and is considered a medical emergency. The patient is often put on a respirator to assist with breathing. Most patients, however, recover from even the most severe cases of Guillain-Barré syndrome, although some continue to have some degree of weakness. Guillain-Barré syndrome is rare. Usually Guillain-Barré occurs a few days or weeks after the patient has had symptoms of a respiratory or gastrointestinal viral infection. Occasionally, surgery or vaccinations will trigger the syndrome. The disorder can develop over the course of hours or days, or it may take up to 3 to 4 weeks. Because the signals traveling along the nerve are slower, a nerve conduction velocity (NCV) test is used to aid diagnosis. Increased protein in the cerebrospinal fluid is also used to diagnose Guillain-Barré syndrome. One or more symptoms of Guillain-Barré syndrome are reduced following treatment with Bacillus coagulans bacteria.
Hashimoto's Thryroiditis
[0038] Hashimoto's thyroiditis is a type of autoimmune disease in which the immune system destroys the thyroid, the gland that helps set the rate of metabolism. It attacks women 50 times more often than men. Symptoms of this disorder include low levels of thyroid hormone, resulting in mental and physical slowing, greater sensitivity to cold, weight gain, coarsening of the skin, and goiter (a swelling of the neck due to an enlarged thyroid gland). Identification of a patient suffering from Hashimoto's thyroiditis is accomplished by identifying one or more of these symptoms in the patient. Currently, thyroid hormone replacement therapy is used to treat this disorder. One or more symptoms of Hashimoto's thyroiditis are reduced following treatment with Bacillus coagulans bacteria.
Graves' Disease
[0039] Graves' disease is one of the most common autoimmune diseases, and impacts women about seven times as often as men. Subjects with Graves' disease produce an excessive amount of thyroid hormone. Symptoms of Graves' disease include weight loss due to increased energy expenditure, increased appetite, heart rate, and blood pressure, tremors, nervousness and sweating, as well as frequent bowel movements. Identification of a patient suffering from Graves' disease is accomplished by identifying one or more of these symptoms in the patient. Treatment options include anti-thyroid drug therapy or removal of the thyroid gland, e.g., surgically or by radioiodine treatment. One or more symptoms of Graves' disease are reduced following treatment with Bacillus coagulans bacteria.
Insulin-Dependent (Type 1) Diabetes
[0040] Type 1 diabetes is caused by too little insulin production in the pancreas, and usually occurs in children and young adults, but it can occur at any age. Symptoms include increased thirst, increased urination, weight loss, fatigue, nausea, vomiting, and frequent infections. Identification of a patient suffering from diabetes is accomplished by identifying one or more of these symptoms in the patient. Insulin treatment is the current treatment modality. One or more symptoms of diabetes are reduced following treatment with Bacillus coagulans bacteria.
Inflammatory Bowel Disease
[0041] Crohn's disease (also called ileitis or enteritis) causes inflammation in the small intestine. Crohn's disease usually occurs in the lower part of the small intestine, called the ileum, but it can affect any part of the digestive tract, from the mouth to the anus. The inflammation extends deep into the lining of the affected organ. The inflammation can cause pain and can make the intestines empty frequently, resulting in diarrhea. Identification of a patient suffering from Crohn's disease is accomplished by identifying one or more of these symptoms in the patient. Crohn's disease is one form of inflammatory bowel disease. Crohn's disease can be difficult to diagnose because its symptoms are similar to other intestinal disorders such as irritable bowel syndrome and to another type of IBD called ulcerative colitis. Ulcerative colitis causes inflammation and ulcers in the top layer of the lining of the large intestine. Crohn's disease affects men and women equally and seems to run in some families. About 20 percent of people with Crohn's disease have a blood relative with some form of IBD, most often a brother or sister and sometimes a parent or child. One or more symptoms of Crohn's disease are reduced following treatment with Bacillus coagulans bacteria.
Ulcerative Colitis
[0042] Ulcerative colitis is a disease that causes inflammation and sores, called ulcers, in the lining of the large intestine. The inflammation usually occurs in the rectum and lower part of the colon, but it may affect the entire colon. Ulcerative colitis rarely affects the small intestine except for the end section, called the terminal ileum. Ulcerative colitis may also be called colitis or proctitis. Symptoms of UC include fatigue, weight loss, loss of appetite, rectal bleeding and loss of body fluids and nutrients. Identification of a patient suffering from UC is accomplished by identifying one or more of these symptoms in the patient. The inflammation makes the colon empty frequently, causing diarrhea. Ulcers form in places where the inflammation has killed the cells lining the colon; the ulcers bleed and produce pus. Crohn's disease differs from ulcerative colitis because it causes inflammation deeper within the intestinal wall. Also, Crohn's disease usually occurs in the small intestine, although it can also occur in the mouth, esophagus, stomach, duodenum, large intestine, appendix, and anus. Ulcerative colitis may occur in people of any age, but most often it starts between ages 15 and 30, or less frequently between ages 50 and 70. Children and adolescents sometimes develop the disease. Ulcerative colitis affects men and women equally and appears to run in some families. One or more symptoms of UC are reduced following treatment with Bacillus coagulans bacteria.
Celiac Disease
[0043] Celiac disease is a digestive disease that damages the small intestine and interferes with absorption of nutrients from food. Subjects with celiac disease cannot tolerate a protein called gluten, which is found in wheat, rye, and barley. When people with celiac disease eat foods containing gluten, their immune system responds by damaging the small intestine. Specifically, the intestinal villi are lost, resulting in malnutrition. Symptoms of Celiac disease include diarrhea, abdominal pain and bloating, gas, irritability, depression, weight loss, delayed growth, failure to thrive in infants, anemia, and fatigue. Identification of a patient suffering from Celiac disease is accomplished by identifying one or more of these symptoms in the patient. Celiac disease is also known as celiac sprue, nontropical sprue, and gluten-sensitive enteropathy. Celiac disease may be induced following surgery, pregnancy, childbirth, viral infection, or severe emotional stress. One or more symptoms of Celiac disease are reduced following treatment with Bacillus coagulans bacteria.
Vasculitis Syndromes
[0044] This is a broad and heterogeneous group of diseases characterized by symptoms including inflammation and damage to the blood vessels, thought to be brought on by an autoimmune response. Identification of a patient suffering from vasculitis is accomplished by identifying one or more of these symptoms in the patient. Any type, size, and location of blood vessel may be involved. Vasculitis may occur alone or in combination with other diseases, and may be confined to one organ or involve several organ systems. One or more symptoms of vasculitis are reduced following treatment with Bacillus coagulans bacteria.
Hematologic Autoimmune Diseases
[0045] Blood also can be affected by an autoimmune disorder. In autoimmune hemolytic anemia, red blood cells are prematurely destroyed by antibodies. Other autoimmune diseases of the blood include autoimmune thrombocytopenic purpura and autoimmune neutropenia. One or more symptoms of these blood disorders are reduced following treatment with Bacillus coagulans bacteria.
[0046] The present inventors recognize that certain autoimmune disorders affect primarily women, as noted for several autoimmune disorders described above. The present invention discloses the prevention or treatment of an autoimmune disorder in a female subject. In embodiments of the invention, the autoimmune disorder to be treated or prevented in a female patient is Hashimoto's disease (also known as hypothyroiditis), systemic lupus erythematosus, Sjogren's syndrome, antiphospholipid syndrome, primary biliary cirrhosis, mixed connective tissue disease, chronic active hepatitis, Graves' disease (also termed hyperthyroiditis), rheumatoid arthritis, scleroderma, myasthenia gravis, multiple sclerosis, or chronic idiopathic thrombocytopenic purpura.
[0000] Bacillus coagulans Therapy Reduces Gastrointestinal Infection by Autoimmune Disease-Associated Pathogenic Microorganisms
[0047] Many species of bacterial, mycotic and yeast pathogens possess the ability to cause a variety of disorders, including autoimmune disorders. Bacillus coagulans , a probiotic microorganism is useful in the prophylactic or therapeutic treatment of autoimmune conditions such as psoriasis, which are associated with infection by these aforementioned pathogens. Generally, Bacillus coagulans bacteria (i) possess the ability to produce and excrete enzymes useful in digestion (e.g., lactase, various proteases, lipases and amylases); (ii) demonstrate beneficial function within the gastrointestinal tract; (iii) serve to down-regulate the cytokine response as a result of bacterial/fungal/or mycotic interaction with the various mucosal cells; and (vi) are non-pathogenic. Bacillus coagulans bacteria are able to inhibit pathogenic yeast and other fungi, including Candida albicans, Candida tropicalis and Trichophyton mentagrophytes, Trichophyton interdigitale, Trichophyton rubrum , and Trichophyton yaoundei. Bacillus coagulans bacteria are also able to inhibit pathogenic bacteria, including Staphylococcus species, Streptococcuspyogenes species, Pseudomonas species, Escherichia coli, Clostridium species, Gardnereia vaginailis, Proponbacterium acnes, Aeromonas species, Aspergillus species; Proteus species; and Klebsiella species.
[0048] Strains of Bacillus coagulans bacteria are available from the American Type Culture Collection (ATCC), including the following accession numbers: Bacillus coagulans Hammer NRS 727 (ATCC No. 11014); Bacillus coagulans Hammer strain C (ATCC No. 11369); Bacillus coagulans Hammer (ATCC No. 31284); Bacillus coagulans Hammer NCA 4259 (ATCC No. 15949); and strains deposited under ATCC Accession Numbers 8038, 35670, 23498, 51232, 12245, 10545 and 7050. Purified Bacillus coagulans bacteria are also available from the Deutsche Sarumlung von Mikroorganismen and Zellkuturen GmbH (Braunschweig, Germany) using the following accession numbers: Bacillus coagulans Hammer 1915 (DSM No. 2356); Bacillus coagulans Hammer 1915 (DSM No. 2383, corresponds to ATCC No. 11014); Bacillus coagulans Hammer (DSM No. 2384, corresponds to ATCC No. 11369); and Bacillus coagulans Hammer (DSM No. 2385, corresponds to ATCC No. 15949). Bacillus coagulans bacteria can also be obtained from commercial suppliers such as K.K. Fermentation (Kyoto, Japan) and Nebraska Cultures (Walnut Creek, Calif.).
[0049] The Bacillus coagulans bacterial strain used to reduce infection by microbial pathogens is Bacillus coagulans hammer, or a strain derived therefrom. For example, the Bacillus coagulans bacterial strain is ATCC 31284, or a strain derived therefrom. These strains include, e.g., ATCC Numbers GBI-20, ATCC Designation Number PTA-6085; GBI-30, ATCC Designation Number PTA-6086; and GBI-40, ATCC Designation Number PTA-6087; see U.S. Pat. No. 6,849,256 to Farmer, the contents of which are incorporated by reference in their entirety.
[0050] A composition comprising Bacillus coagulans bacteria in a pharmaceutically acceptable carrier suitable for oral administration to the gastrointestinal tract of a mammal (e.g., a human) animal is disclosed. Bacillus coagulans bacteria are provided in amounts sufficient to colonize the gastrointestinal tract of a mammal. The invention provides Bacillus coagulans bacteria at a concentration of from about 1×10 4 to about 1×10 12 viable bacteria, specifically about 1×10 6 to about 1×10 11 , more specifically about 1×10 8 to about 1×10 10 , and most specifically about 8×10 8 . Bacillus coagulans bacteria are provided as vegetative cells, spores, or a combination thereof.
[0051] Vegetative cells are formulated in a composition that protects the cells from being killed by the acid environment of the stomach. Cells formulated in this manner successfully traverse the stomach to colonize the small and/or large intestine. Accordingly, the invention includes a composition containing a Bacillus coagulans bacterium in a pharmaceutically acceptable acid-resistant (“enteric”) carrier. By acid-resistant is meant that the carrier or coating does not dissolve in an acidic environment. An acidic environment is characterized by a pH of less than 7. The acid-resistant carrier is resistant to acids at pH less than about 4.0. Preferably, the carrier does not dissolve in pH 2-3. Most preferably, it does not dissolve in pH of less than 2. To protect vegetative bacterial cells from stomach acids, the cells are coated or encapsulated with the acid-resistant carrier. The composition optionally includes other components such as glucose and phosphoric acid or other nutrient compounds to increase bacterial growth after removal of the carrier or coating. The invention also includes Bacillus coagulans bacteria in the form of spores, which are selected for the capability of germinating in the presence of bile acids such as cholic, deoxycholic and tauro-deoxycholic acids. Enterically coated and bile acid-resistant Bacillus coagulans bacteria are described in U.S. Ser. No. 10/287,904, filed Nov. 5, 2002, the contents of which are incorporated by reference in their entirety.
[0052] The compositions contain Bacillus coagulans bacteria and one or more biologically active compounds; such as a natural or synthetic compound that decreases or relieves a symptom of psoriasis. Exemplary compounds include immunosuppressants including methotrexate, cyclosporine, hydroxyurea, mycophenolate mofetil, sulfasalazine, 6-thioguanine, and other compounds such as retinoids.
EXAMPLE 1
Preparation of Bacillus coagulans Bacteria
[0053] I. Preparation of Vegetative Bacillus coagulans
[0054] Bacillus coagulans is aerobic and facultative, and is typically cultured at pH 5.7 to 6.8, in a nutrient broth containing up to 2% (by wt) NaCl, although neither NaCl, nor KCl are required for growth. A pH of about 4.0 to about 7.5 is optimum for initiation of sporulation (i.e., the formation of spores). The bacteria are optimally grown at 20° C. to 45° C., and the spores can withstand pasteurization. Additionally, the bacteria exhibit facultative and heterotrophic growth by utilizing a nitrate or sulfate source. Bacillus coagulans strains and their growth requirements have been described previously (see e.g., Baker, D. et al, 1960. Can. J. Microbiol. 6: 557-563; Nakamura, H. et al, 1988. Int. J. Syst. Bacteriol. 38: 63-73. In addition, various strains of Bacillus coagulans can also be isolated from natural sources (e.g., heat-treated soil samples) using well-known procedures (see e.g., Bergey's Manual of Systemic Bacteriology , Vol. 2, p. 1117, Sneath, P. H. A. et al., eds. Williams & Wilkins, Baltimore, Md., 1986).
[0055] Bacillus coagulans bacteria are cultured in a variety of media, although it has been demonstrated that certain growth conditions are more efficacious at producing a culture that yields a high level of sporulation. For example, sporulation enhanced by supplementing the culture medium with 10 mg/l of MgSO 4 sulfate, yielding a ratio of spores to vegetative cells of approximately 80:20. In addition, certain culture conditions produce a bacterial spore that contains a spectrum of metabolic enzymes particularly suited for the present invention (i.e., production of lactic acid and enzymes for the enhanced probiotic activity and biodegradation). Although the spores produced by these aforementioned culture conditions are preferred, various other compatible culture conditions that produce viable Bacillus coagulans spores are utilized in the practice of the present invention.
[0056] Suitable media for the culture of Bacillus coagulans include: TSB (Tryptic Soy Broth), GYE (Glucose Yeast Extract Broth), and NB (nutrient broth), which are all well known within the field and available from a variety of sources. Media supplements which contain enzymatic digests of poultry and/or fish tissue, and containing food yeast are particularly preferred. A preferred supplement produces a media containing at least 60% protein, and about 20% complex carbohydrates and 6% lipids. Media can be obtained from a variety of commercial sources, notably DIFCO (Newark, N.J.); BBL (Cockeyesville, Md.); and Troy Biologicals (Troy, Md.)
[0000] II. Preparation of Bacillus coagulans Spores
[0057] A culture of dried Bacillus coagulans Hammer bacteria (ATCC No. 31284) spores was prepared as follows. Approximately 1×10 7 spores were inoculated into one liter of culture medium containing: 30 g (wt./vol.) Tryptic Soy Broth; 10 g of an enzymatic-digest of poultry and fish tissue; and 10 g MnSO 4 . The culture was maintained for 72 hours under a high oxygen environment at 37° C. so as to produce a culture having approximately 6×10 9 cells/gram of culture. The culture was then centrifuged to remove the liquid culture medium and the resulting bacterial paste was re-suspended in 100 ml of sterile water and 20% malto-dextrin and lyophilized. The lyophilized bacteria were ground to a fine powder by use of standard good manufacturing practice (GMP) methodologies.
EXAMPLE 2
Formulations and Administration
[0058] Vegetative bacterial cells and spores are administered at a dose of 10,000-10 11 cells per administration. A typical therapeutic composition of the present invention contains in a one-gram dosage formulation, from approximately 1×10 3 to 1×10 12 , and preferably approximately 2×10 5 to 2×10 10 , colony-forming units (CFU) of viable Bacillus bacteria (i.e., vegetative bacteria) or bacterial spores. Typically, Bacillus coagulans bacteria remain in and colonize the colon for a period of 3-5 days post-administration.
[0000]
Formulation #1
Bacillus coagulans
8.0 × 10 8 (53 mg)
Saccharomyces
boulardii
1.5 × 10 8 (7.5 mg)
Copper Sulfate
5
mcg
Vitamin C
50
mg
Selenium
2.5
mcg
Micro-Crystalline Cellulose
132
mg
Total
250
mg
Formulation #2
Bacillus coagulans
8.0 × 10 8 (53 mg)
Saccharomyces
boulardii
1.5 × 10 8 (7.5 mg)
L-Lysine
75
mg
Maltodextrin
35
mg
Blue lake #1 Dye
1
mg
Aspartame
2
mg
Compressible Sugars
173
mg
Total
350
mg
Formulation #3
Bacillus coagulans
1.5 × 10 9 (100 mg)
Maltodextrin
35
mg
Microcrystalline Cellulose
140
mg
Total
350
mg
Formulation #4
Bacillus coagulans
1.5 × 10 9 (100 mg)
Sarccharomyces boulardii
2.5 × 10 8 (12.5 mg)
L-Lysine
75
mg
Microcrystalline Cellulose
163
mg
Total
350
mg
Formulation #5
Bacillus coagulans
1.5 × 10 9 (100 mg)
L-Lysine
75
mg
Fluconazole 2%
150
mg
Filler
25
mg
Total
350
mg
[0059] The invention provides for the addition of other useful ingredients. Many individuals that suffer from immune disorders of this nature also have been shown to have vitamin and mineral deficiencies. Hence, addition of vitamin and mineral supplements is useful for the dietary management of these disorders.
EXAMPLE 3
Use of Bacillus coagulans Bacteria in the Treatment and Clinical Remission of Chronic Psoriasis
[0060] Probiotic bacteria reduce the numbers of pathogens in the gut of humans and animals. In addition, Bacillus coagulans bacteria downregulate the body's cytokine response to toxins and pathogenic organisms.
[0061] A number of deleterious microorganisms promote over-stimulation of immune system. In the case of psoriasis, this leads to the production of cytokines (TNF-α) that cause the formation of dermal plates. Candida albicans is the underlying infection in these circumstances. It is common for physicians today to prescribe systemic antifungal compounds to reduce psoriatic lesions. Unfortunately, the antifungal most often used in these circumstances is Fluconazole, which can only be used for 30 days (as per FDA guidelines). With these issues in mind, studies were carried out to determine whether Bacillus coagulans lactic acid bacteria could be employed to reduce the number of Candida species in the stool while down regulating the production of TNF-α as a result of the Candida infection.
[0062] Twelve human patients with chronic psoriasis were studied at a General practice clinic in Cleveland, Ohio over a three-month period. Patients were provided with capsules containing Bacillus coagulans bacteria (7.5×10 8 colony forming units (CFU)) and microcrystalline cellulose as a carrier, and instructed to take two capsules per day. There were no restrictions on the time of day of consumption or if the two capsules were taken at the same or different times during the day. The treatment lasted three months; patients were observed at the beginning and end of the treatment.
[0063] Results after a two-month period indicated that Bacillus coagulans therapy was nearly 100% effective in reducing the surface area of psoriatic plates in patients suffering from Psoriasis vulgaris. The physician that conducted the study did not that a few younger patients (16-25 years of age) that had plates over >60% of their respective bodies did show results much quicker than the patients that were older (50 years of age or older), and had been affected by the disease for a much longer period (>20 years). Five patients that showed excellent results after therapy discontinued use of the formulation (for various reasons) and their psoriatic plates returned very quickly. After re-initiating therapy, the plates started to recede again. This indicates that the underlying Candida infection may not be totally eliminated and that a longer period of therapy may be required to maintain the results. Moreover, some individuals are more susceptible to mycotic infection and as a result, these individuals need to manage this state with continued use of the formulation. The usage parameters may be different for dietary management after initial results but, to guarantee that the initial results are maintained, the a minimum of one capsule a day ongoing may be sufficient.
EXAMPLE 4
Use of Bacillus coagulans Bacteria to Reduce Serum TNF-α Levels
[0064] Colonization of the mammalian gastrointestinal tract by pathogenic microorganisms leads to the aberrant production of cytokines (e.g., TNF-α), which cause symptoms of psoriasis, such as dermal plates. Oral administration of Bacillus coagulans bacteria is examined for the ability to decrease cytokine production in human subjects suffering from or at risk of developing psoriasis.
Materials and Methods
[0065] Subjects are identified by the presence or past incidence of one or more symptoms of psoriasis, or by a family history of the disease (one or more parents, grandparents or siblings having one or more symptoms of psoriasis). Non-affected individuals are used as controls. Serum cytokine levels are determined prior to Bacillus coagulans bacteria treatment, at regular intervals throughout the duration of the treatment, and upon completion of the treatment. Measured cytokines include TNF-α and interleukin-6 (IL-6). Measurement of serum cytokine levels is performed by methods known in the art, such as ELISA. Bacillus coagulans bacteria are administered to affected and non-affected subjects such that at least about 1×10 6 viable Bacillus coagulans bacteria are delivered in the gastrointestinal tract of each subject per day. Treatments last at least about 10 days, e.g., about 10, 15, 20, 30, 45, 60, 75, 90 or 120 days.
Results
[0066] Human patients suffering from or at risk of developing psoriasis have higher levels of TNF-α than non-affected controls. Treatment with Bacillus coagulans bacteria results in a decrease in serum TNF-α 0 levels in affected subjects.
EXAMPLE 5
Medical Foods Containing Bacillus coagulans Bacteria
[0067] A “medical food” means a food which is formulated to be consumed or administered enterically under the supervision of a physician and which is intended for the specific dietary management of a disease or condition for which distinctive nutritional requirements, based on recognized scientific principles, are established by medical evaluation. (See, 21 USC 360ee(b)(3)). For subjects suffering from or at risk of developing an autoimmune disease, the compositions containing Bacillus coagulans bacteria are nutritionally complete formulas of medical foods. Alternatively, the compositions containing Bacillus coagulans bacteria are nutritionally incomplete formulas of medical foods.
[0068] Medical foods containing Bacillus coagulans bacteria are specially formulated and processed for subjects suffering from or at risk of developing an autoimmune disease, such as a subject who requires the medical as a major treatment modality. Typically, the medical foods containing Bacillus coagulans bacteria medical foods are formulated as an enteral nutrition product, i.e., it is provided through the gastrointestinal tract, taken by mouth, or provided through a tube or catheter that delivers nutrients beyond the oral cavity or directly to the stomach. The medical food is formulated to provide at least about 1×10 6 viable Bacillus coagulans bacteria in the gastrointestinal tract of a mammalian subject per day, based on a serving size of about 1 gram to about 2 grams of the medical food taken up to about twice a day. The medical food also optionally includes a non-microbially derived anti-fungal agent, an immunosuppressive agent, or a non-microbially derived anti-fungal agent and an immunosuppressive agent.
[0069] Subjects for whom medical foods containing Bacillus coagulans bacteria are appropriate are identified by the presence or past incidence of one or more symptoms of an autoimmune disease such as psoriasis, or by a family history of the disease (one or more parents, grandparents or siblings having one or more symptoms of an autoimmune disease).
EXAMPLE 6
Use of Bacillus coagulans Bacteria in the Treatment of Other Autoimmune Disorders
[0070] Twelve human patients with Crohn's disease were studied at a general practice clinic in Cleveland, Ohio over a one-month period. Patients were provided with capsules containing Bacillus coagulans bacteria (1.5×10 9 colony forming units (CFU)) and microcrystalline cellulose as a carrier, and instructed to take one capsule per day. There were no restrictions on the time of day of consumption. The treatment lasted one month; patients were observed at the beginning and end of the treatment.
[0071] Results after one month indicated that all 11 out of 12 patients responded well to the formulation. One patient dropped out without explanation. The incidence of diarrhea was reduced by over 75% and abdominal pain and spasms were reduced significantly. Crohn's disease is diagnosed symptomatically; thus, a significant reduction in the number and severity of symptoms experienced each day is a notable improvement in individuals that suffer from this disease.
[0072] Other embodiments are within the following claims.
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The present invention describes the use of lactic acid bacteria, particularly lactic acid producing members of the genus Bacillus , in treating digestive-related immune disorders by downregulating of cytokines and by inhibiting pathogenic or deleterious microorganisms in the gastrointestinal tract. Specific formulations of Bacillus coagulans for various immune disorders are elaborated.
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[0001] This application hereby claims priority under 35 U.S.C. §119 to U.S. Provisional Patent Application No. 61/310,701, filed on Mar. 4, 2010 entitled SNOW DOLLY, by inventor Richard Yancheski, which is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] The present invention relates generally to the fields of snow removal and garden tools.
[0003] Snow shovels and snow blowers are the standard equipment used to remove snow both residentially and commercially. Use of a snow shovel entails significant physical exertion, both aerobic exercise and weight-lifting. Weight lifting can raise blood pressure and rapidly increase the load on the heart. In cold weather, arteries and blood vessels constrict, reducing blood supply when the load on the heart is high. Hormones released during cold weather and exercise can cause arterial plaques to rupture, causing blood clots and heart attacks. Each year, several hundred people experience a heart attack while shoveling snow. Deaths from heart disease increase 22% in the week following a snowstorm.
[0004] Muscle and spinal injuries are extremely common. More than 70,000 people ended up with a shoveling-related injury bad enough to trigger a doctor's visit in 2008. A quarter of those people visited an emergency room, and about 900 were admitted to a hospital. Lower back and shoulder strains, herniated disks, and fractures from falls are the most common snow shoveling injuries.
[0005] Needless to say, many elderly or disabled people are unable to use snow shovels because the physical effort required is simply too great. Demographics are shifting towards a more elderly population, particularly in developed countries. Clearing snow using known methods is a serious challenge for these populations.
[0006] Snow blowers are an alternative to snow shovels. However, snow blowers are quite expensive, ranging from a few hundred dollars for personal/residential models to a thousand dollars and up for commercial snow blowers. They typically utilize gas powered engines, which emit high levels of pollutants and potentially dangerous fumes. They require oil and regular maintenance because of the large number of moving parts. Used oil must be disposed of properly to avoid environmental contamination. The moving parts can strike a body part, causing injury, or another obstacle, causing damage to the machine. Repair and maintenance increase costs to the user. Especially for larger models, the high weight of these machines makes use very difficult for the disabled or elderly, and on steps or other areas where the machines are cumbersome to maneuver.
[0007] Needs exist for improved tools for removing snow.
SUMMARY
[0008] It is to be understood that both the following summary and the detailed description are exemplary and explanatory, and are intended to provide further explanation of the invention as claimed. Neither the summary nor the description that follows is intended to define or limit the scope of the invention to the particular features mentioned in the summary or in the description.
[0009] In certain embodiments, the disclosed embodiments may include one or more of the features described herein.
[0010] A new snow removal device and all-purpose shovel plow has a body, a shovel connected to the body and positioned at a lower end of the body, a snow catcher connected to the body, and one or more motive elements selected from the group consisting of wheels, rollers, treads, and slides. The snow catcher is positioned behind the shovel such that when the shovel is tilted back, loose material transfers from the shovel to the snow catcher.
[0011] The shovel is positioned such that when the body is tilted back, the shovel also tilts back, allowing loose material to spill from the shovel into the snow catcher. A handle is positioned at a top end of the body. The body acts as a lever arm on the shovel, allowing a heavy load to be tilted back in the shovel when the handle is tilted back with little force from the user.
[0012] A foot pedal connected to the body facilitates pushing the shovel into loose material. In one embodiment, the motive elements comprise of wheels. The angle between the body and shovel is 120 degrees. The body is partially or completely collapsible. The snow catcher is equipped with an outer lip that retains loose material within the snow catcher. The shovel has sidewalls for retaining loose material within the shovel before the loose material is transferred to the snow catcher. One or more of the motive elements serves as a pivot point when the snow removal device is placed on the ground in operating position.
[0013] In a new snow removal device method, a shovel is positioned at a shovel position at a lower end of a body, and is connected to the body. A snow catcher is positioned behind the shovel position, and is connected to the body. One or more motive elements selected from the group consisting of wheels, rollers, treads, and slides are connected to the body. The snow catcher is positioned such that when the shovel is tilted back, loose material in the shovel transfers from the shovel to the snow catcher.
[0014] These and other objectives and features of the invention are apparent in the disclosure, which includes the above and ongoing written specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate exemplary embodiments and, together with the description, further serve to enable a person skilled in the pertinent art to make and use these embodiments and others that will be apparent to those skilled in the art.
[0016] FIG. 1A is a front view diagram of an embodiment of a shovel and snow catcher.
[0017] FIG. 1B is a perspective view diagram of an embodiment of a snow removal device.
[0018] FIG. 2 is a top view diagram of an embodiment of a snow removal device.
[0019] FIG. 3 is a front elevated view of an embodiment of a snow removal device.
[0020] FIG. 4 is a front elevated view of a snow removal device with the shovel portion flipped upwards.
[0021] FIG. 5 is a side elevated view of an embodiment of a snow removal device.
[0022] FIG. 6 is a perspective detail of a foot pedal for an embodiment of a snow removal device.
[0023] FIG. 7 is a side elevated view of an embodiment of a snow removal device.
DETAILED DESCRIPTION
[0024] A snow removal device will now be disclosed in terms of various exemplary embodiments. This specification discloses one or more embodiments that incorporate features of the invention. The embodiment(s) described, and references in the specification to “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment(s) described may include a particular feature, structure, or characteristic. Such phrases are not necessarily referring to the same embodiment. When a particular feature, structure, or characteristic is described in connection with an embodiment, persons skilled in the art may affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
[0025] In the several figures, like reference numerals may be used for like elements having like functions even in different drawings. The figures are not to scale. The embodiments described, and their detailed construction and elements, are merely provided to assist in a comprehensive understanding of the invention. Thus, it is apparent that the present invention can be carried out in a variety of ways, and does not require any of the specific features described herein. Also, well-known functions or constructions are not described in detail since they would obscure the invention with unnecessary detail.
[0026] A new green technology snow removal device requires no lifting, minimal exercise, and very minimal back or muscle movements to operate. It is similar in overall appearance to a standard dolly (e.g., furniture/box transportation), but attached to the front of the snow removal device is an exceptionally well-developed shovel. The shovel is positioned at a greater than 90 degree angle to the body of the snow removal device. In one embodiment, this angle is about 120 degrees. This makes it easier to push the device forward while maintaining contact between the base and the ground for snow removal applications because the angle between the shovel and the body of the snow removal device creates the effect of a lever. In one embodiment, there is a hinge between the shovel and the body of the snow removal device, allowing a user to set the desired angle. A larger angle makes pushing easier, but may require bending over for taller individuals. A locking device similar to those used on lawn mower wheels for height settings is used to maintain the desired angle.
[0027] The shovel is wide and flat to the ground like a blade and tapers off into snow catcher, in one embodiment a circular disc with a rim. The shovel and snow catcher are attached to the body of a snow removal device. The shovel and snow catcher are attached to the body by soldering or welding. In one embodiment, the snow removal device is made of a durable, lightweight material such as aluminum. The snow removal device has large wheels, allowing the person using the snow removal device to easily push the shovel into the snow. Any combination of wheels, rollers, treads, slides, or similar means for movement could be used. Once the snow removal device is into the snow the user pushes down onto the body of the snow removal device to let the snow be lifted and it automatically drops into the snow catcher. Because of the large lever arm of the snow removal device and the high handle, this action requires little effort or bending, even for deep snow. Standard dollies are used to easily transport heavy furniture, such as refrigerators, making snow transport trivial for a snow removal device utilizing a similar structure.
[0028] The next step for the user is to wheel the snow removal device away to where the user would like to move the snow. With a simple twist of the snow removal device, the snow falls right out where the user wants it. The snow catcher works like a wheel barrel in that it easily allows the user to remove the snow with minimal exercise of the back, arms, neck, etc.
[0029] The new snow removal device replaces the need for snow blowers and cuts down on the pollution caused by small engines. The deeper the snow, the better it works. The cost of the new snow removal device is under 100 dollars, thus saving consumers thousands on unneeded, bulky snow blowers.
[0030] In one embodiment, the snow removal device can be folded for easy storage and even fit into the trunk of a car. The body of the snow removal device and handle of the snow removal device fold down. This can be accomplished in a manner similar to a typical lawnmower, with a hinge or pivot point on the body of the snow removal device that can be locked in place with a knob that turns to loosen or tighten the connection. In an alternative embodiment, the body of the snow removal device collapses in a telescoping fashion, similar to that of luggage handles. However, the body of the snow removal device must remain sturdy enough to bear the weight of the loose material being carried. In one embodiment there is a foot pedal on the back of the snow removal device to make it easy for the user to push the snow removal device into the snow.
[0031] The snow removal device is ideal for any business or government sidewalk clearing as well as car clearing. The device provides the elderly, disabled, and people with back problems the opportunity to clear their vehicles in case there is an emergency, such as needing to pick up their medications, going to the hospital, or getting stuck in the snow on while driving. Almost anyone can use this device at a time of need. Because it has no motor, users do not have to go to the gas station and get gas for the snow removal device. Users can use it immediately during a storm and clear their driveways without over exerting themselves. This snow removal device revolutionizes the way snow is shoveled and will reduce the number of emergency room visits from people injuring their backs and necks lifting and twisting while removing snow.
[0032] Additionally, this snow removal device is useful to the number of people who simply hate shoveling snow. The device is essential for workers who shovel snow as part of their job to prevent back injuries at work. The device is useful for government, private organizations, public sidewalk clearing, schools, and any place that needs its snow removed.
[0033] The snow removal device is a convenient and versatile tool. It has many uses other than snow removal, for example it can be used as a garden tool. The snow removal device can be used as a wheel barrel and gravel and mulch spreader. Using the same principles as for snow removal, the snow removal device can be used to easily scoop up large quantities of any relatively loose material, transport it to a desired location, and deposit it without excessive exertion or wear and tear on the back or other muscles.
[0034] The snow removal device serves as a better wheel barrel than a conventional wheel barrel, particularly in embodiments where it uses two tires and is therefore designed better for use in the yard. The weight is more easily distributed so that it is easier to push or pull around rough terrain. The snow removal device is excellent for cleaning up yard leaves. The user can fill snow catcher with leaves, wheel the snow removal device to a compost pile or other location, and, with a twist of the wrist, dump the leaves. While pulling weeds, a user can lay the snow removal device down, sit on the body, drape a bag over the snow catcher and deposit the weeds into the bag, tie the bag, and haul it to the trash collection area. It is not necessary to pick up the bag of weeds.
[0035] Furthermore, the snow removal device works well as a mulch or gravel spreader. A bag of mulch or gravel may be placed in the snow catcher, and wheeled to where the gravel or mulch is to be placed. The user can then cut the bottom of the bag, tilt the snow removal device in an upward position, and allow the gravel or mulch to go down through the shovel for spreading.
[0036] In an exemplary embodiment, the shovel on the front of the snow removal device is 16″ wide at its forward edge and flat to the ground like a blade. The bottom cross section of the shovel is roughly trapezoidal in shape, with 16″ sides tapering back towards the snow catcher. The shovel is like a flat blade on the first inch of the forward edge, and then side walls appear on the shovel, rising from about a quarter of an inch high towards the front to two inches high at the back, matching the depth of the snow catcher. The sides on the shovel act like a guide or slide to keep the snow directed into the snow catcher. In other embodiments, the sides of the shovel are an even 1″ high or 2″ high. The snow catcher is a 24″ circular disc with a 2″ high lip, providing a 2″ deep snow catching area. The snow removal device body is about 46″ long for high leverage and ease of standing use. The wheels are 10-12″ in diameter so that the snow removal device can easily be pushed into the snow. The snow removal device body is at a 120 degree angle with the shovel. In an alternative embodiment, the shovel is 20″ wide at its forward edge.
[0037] A simple embodiment of a snow removal device can be constructed by attaching a shovel, for example formed by sheet metal, to the base of a standard device and fixing a trashcan lid or similar to the back of the snow removal device behind the shovel by welding or a simple attachment mechanism, such as bungee cords.
[0038] FIG. 1A is a front view diagram of a shovel 3 and snow catcher 5 . Snow catcher 5 is connected to shovel 3 and has a lip 15 for retaining snow. Shovel 3 has sides 13 for retaining snow.
[0039] FIG. 1B is a perspective view diagram of a snow removal device. The snow catcher 5 and shovel 3 are attached to a body 7 . Further attached to body 7 is a handle 9 . The wheels 11 are attached to the snow catcher 5 and body 7 . The body 7 is at about a 120 degree angle 17 with the ground and shovel 3 . Also attached to the body 7 is a foot pedal 1 .
[0040] FIG. 2 is a top view diagram of a snow removal device.
[0041] FIG. 3 is a front elevated view of an embodiment of a snow removal device. Dolly body 301 has hook 319 for carrying pails or other items and stand 317 for resting on a horizontal surface in an elevated position and is connected to shovel portion 305 . Shovel portion 305 has raised sides 307 to keep snow or other loose material in the shovel portion 305 and is attached to lifting bar 313 with stabilizing bar 309 and fasteners 311 . Wheels 315 transport the device.
[0042] FIG. 4 is a front elevated view of a snow removal device with the shovel portion 405 flipped upwards. In this view, the attachment of the shovel portion 405 to the dolly foot 421 can be seen. Pivot bar 425 connects to the dolly foot 421 at edges 423 . The pivot bar 425 is mounted through cradles 426 of the shovel portion 405 , allowing the shovel portion to rotate about the pivot bar 425 while being secured to the dolly foot 421 .
[0043] FIG. 5 is a side elevated view of an embodiment of a snow removal device. Here, the rear foot pedal 527 can be seen, and in this figure is being actuated by a user's foot 529 , flipping the shovel portion 505 towards the snow catcher 503 . In this figures, the pedal is partially depressed, and therefore the shovel portion 505 partially raised. Fully depressing the pedal 527 flips the shovel portion 505 vertical, flipping any load carried in the shovel portion 505 into the catcher 503 .
[0044] FIG. 6 is a perspective detail of a foot pedal for an embodiment of a snow removal device. The pedal portion 631 of foot pedal 627 , which was obscured by the user's foot in FIG. 5 , is shown. The foot pedal connects to the lifting bar 513 , which is connected to the shovel portion, through gap 630 in the catcher plate/snow catcher 603 , using a simple cam device to flip the shovel portion upward and into the catcher plate 603 when the pedal 631 is depressed.
[0045] FIG. 7 is a side elevated view of an embodiment of a snow removal device. Here, stationary foot pedal 733 is shown, which is a good place for a user to push its foot against to dig the shovel portion into snow or other material.
[0046] The invention is not limited to the particular embodiments described above in detail. Those skilled in the art will recognize that other arrangements could be devised, for example, various shapes and sizes of shovel, snow catcher, wheels, and dolly/body. While the invention has been described with reference to specific illustrative embodiments, modifications and variations of the invention may be constructed without departing from the scope of the invention.
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A snow removal device has a body, a shovel connected to the body and positioned at a lower end of the body, a snow catcher connected to the body, and one or more motive elements. The snow catcher is positioned behind the shovel such that when the shovel is tilted back, loose material in the shovel falls into the snow catcher. When the body is tilted back, the shovel also tilts back. The body acts as a lever arm on the shovel, allowing heavy loads to be tilted back with minimal force. A foot pedal facilitates pushing the shovel into loose material. The angle between the body and shovel is 120 degrees. The body is collapsible. The snow catcher has an outer lip and the shovel has sidewalls for retaining loose material. One or more of the motive elements serves as a pivot point for the snow removal device.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority to co-pending U.S. provisional application 60/009,568 filed Dec. 27, 1995.
FIELD OF THE INVENTION
This invention relates to photodector arrays for sensing radiant energy and more particularly to electrical circuitry in a photodetector array to read out photodetectors with fewer devices and with reduced noise.
BACKGROUND OF THE INVENTION
With the advent of multimedia communications, there arises the need for low-cost solid state imagers to complement each communication device and computer. The image input device is central to any teleconferencing and multimedia application. An important advantage of Complementary Metal Oxide Semiconductor (CMOS) imagers is that signal processing circuits can be readily integrated on the same chip as the imager, thus enabling the design of smart single-chip cameral systems. CMOS imagers are inherently cheaper than conventional Charge Coupled Devices (CCD's) because CMOS imagers can be manufactured in conventional CMOS fabrication lines without any process modification.
Moreover, the design of CMOS imagers are easier to design and build than CCD's which require an intimate knowledge of the device physics, the fabrication technology and the readout circuitry.
One embodiment of an active-pixel CMOS imager is described in a publication by S. K. Mendis et al., "A 128×128 CMOS Active Pixel Image Sensor for Highly Integrated Imaging Systems," Int'l Electron Devices Meeting, p. 583, 1993. Mendis et al. shows a single stage CCD imager incorporating an MOS photogate as the light sensitive element. The photo-charge collected below the photogate is transferred through a dc-biased transfer gate to a floating diffusion diode which is periodically reset to a power supply potential. The voltage on the floating diode is detected by a source follower circuit with a row-select switch. The reset noise is removed by subtracting the signal level from the reset level obtained from the same pixel time, thus the kT/C noise of the reset switch is removed. The reset level and the signal level are stored on two separate capacitors via two separate switches and two identical readout circuits. Further differential amplification at the multiplexed column output is required to complete the removal of reset noise.
In a publication by M. H. White et al., "Characterization of Surface Channel CCD Image Arrays at low Light Levels," IEEE Journal of Solid State Circuits, Vol. SC-9, P. 1, 1974, reduction of reset noise was described by a correlated double sampling technique where the signal level was subtracted from the reset level obtained from the same pixel time.
The use of separate switches and capacitors as shown in Mendis et al. to store the reset level and to sample the signal level introduces error. In addition, a large physical layout is required to implement two parallel signal paths, one for reset and one for the signal.
SUMMARY OF THE INVENTION
In accordance with the present invention, an apparatus for sensing radiant energy is described comprising an array of photodetectors for generating charge in response to radiant energy and for transferring the charge to a respective semiconductor region on a semiconductor substrate, each photodetector having the semiconductor region coupled to the gate of a first field effect transistor, the drain of the first field effect transistor coupled to a first power supply lead, the source of the first field effect transistor coupled to the drain of a second field effect transistor, the gate of the second field effect transistor coupled to a first control signal for selecting the respective photodetector, the sources of a plurality of the second field effect transistors coupled together and to one side of a resistive load to provide an output, the other side of the resistive load coupled to a power supply lead.
The invention further provides an amplifier comprising a first capacitor and an inverter coupled in series and a second capacitor coupled in parallel to the inverter. The inverter may be a CMOS inverter. The gain of the amplifier may be adjusted by adjusting the values of the first and second capacitor.
The invention further provides a readout circuit for xy-addressable active-pixel CMOS imagers. The readout circuit employs the same capacitor to clamp the reset level and to sample the signal level for the correlated double sampling operation.
The invention further provides a simple gain stage comprising a CMOS inverter, an input capacitor, and a feedback capacitor. The gain stage is suitable for each column of a photodetector array and also provides a dynamic gain compression function which is programmable.
The invention further provides a CMOS or MOS image input device for computer peripherals for multimedia applications, communications and solid-state imaging.
DESCRIPTION OF THE DRAWING
These and other features, objects, and advantages of the present invention will become apparent upon consideration of the following detailed description of the invention when read in conjunction with the drawing in which:
FIG. 1 is one embodiment of the invention.
FIGS. 2A-2G show typical timing waveforms for operation of the embodiment of FIG. 1; and
FIG. 3 is a graph of the output versus input transfer function of the gain stage shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a photodetector array 10 is shown for detecting radiant energy shown by arrows 6-9. Photodetectors 11-14 are arranged in 2 rows and 2 columns to form a 2×2 array 10 which may be expanded to for example 1024×1024 by inserting additional rows and columns.
Photodetector 11 is shown in part in FIG. 1 as a cross-section view of a semiconductor substrate 16 having a layer 17 of p type material with a layer 18 thereover of p- type material. Substrate 16 may be for example Si, SiGe, Ge, and GaAs.
A dielectric layer 20 such as silicon dioxide may be formed on the upper surface of layer 18. A photogate 22 thin enough or of a material to pass radiant energy may be formed on dielectric layer 20. An n+ type region 24 adjacent one side of photogate 22 may be formed in the upper surface of layer 18. A transfer gate 26 may be formed on dielectric layer 20 adjacent said n+ type region 24. An n+ type region 28 adjacent one side of transfer gate 26 may be formed on dielectric layer 20. A reset gate 30 may be formed on dielectric layer 20 adjacent said n+ type region 28. An n+ type region 32 may be formed in the upper surface of layer 18 adjacent reset gate 30. n+ type region 32 may be coupled to Voltage Source VDD.
Two n type transistors 34 and 36 which may be formed in an isolated p well are coupled in series, source to drain, with the drain of transistor 34 coupled over lead 35 to Voltage Source VDD and the source of transistor 36 coupled to lead 37 which is connected in common with the source of other transistors of other photodetectors in a column.
n+ region 28 is coupled over lead 39 to the gate electrode of transistor 34. n+ region 28 may be a floating diode which holds the charge transferred via transfer gate 26 from beneath photogate 22.
Each photodetector 12-14 may be the same as photodetector 11 with corresponding reference numbers increased by 20 reference numbers with respect to the photodetector before it.
Signal PG is coupled over lead 101 to photogates 22, 42, 62 and 82. Voltage V1 is coupled over lead 102 to transfer gates 26, 46, 66, and 86. Voltage V1 may be a dc voltage intermediate of VDD and Vss. Signal RESET1 may be coupled over lead 103 to reset gates 30 and 70, corresponding to row 1 of photodetector array 10. Signal RESET2 may be coupled over lead 104 to reset gates 50 and 90 corresponding to row 2 of photodetector array 10.
Photogates 22, 42, 62 and 82 and the region below in layer 18 sense the image. N+ regions 24 and 28 and gate 26 forms a field effect transistor which is dc-biased to transfer charge to n+ region 28. N+ region 28 is a floating diffusion diode on which photocharge is dumped after collection by the photogate 22. N+ region 28, gate 30 and n+ region 32 forms a reset switch or field effect transistor to set n+ region 28 to a known potential (VDD-VTH) at each time a row is selected for read out. Row decoder 108 generates signals during each frame to select the pixel rows, one at a time.
Address signals A1 and A2 are coupled over leads 106 and 107 respectively to Row Decoder 108. Timing select signal TS is coupled over lead 109 to Row Decoder 108 to provide an output signal on one of leads 110 and 111 dependent upon the address signals A1 and A2. Signal Select1 on lead 110 is coupled to the gates of transistors 36 and 76. Signal Select2 on lead 111 is coupled to the gates of transistors 56 and 96.
Photodetectors 11 and 12 of column 1 of photodetector array 10 are coupled to lead 37. The photodetector selected by Row Decoder 108 will provide electrical current depending upon the voltage of the gate of transistor 34 or 54. Transistor 114 has its drain coupled to lead 37, its gate coupled over lead 115 to Voltage V2 and its source coupled to Vss. If photodetector 11 is selected, transistors 34, 36 and 114 form a source follower circuit with the output being on lead 37. The source follower circuit converts the charge signal at the floating n+ region 28 into a voltage signal on lead 37. Lead 37 is coupled to the input of amplifier 116 via one side of capacitor 117. The other side of capacitor 117 is coupled over lead 118 to an input of amplifier 119 which may be for example a CMOS inverter, to one side of capacitor 120 and to the drains of transistors 122 and 123. The output of amplifier 119 is coupled over lead 125 to the other side of capacitor 120, the sources of transistors 122 and 123 and to the drains of transistors 126 and 127. Capacitor 117 serves to store the reset level from the selected photodetector and ac couple the photocharge signal to amplifier 119. Amplifier 116 has an ac coupled feedback capacitor 120. The gain of amplifier 116 is the ratio of capacitance of capacitor 117 to capacitor 120. Amplifier 116 is dc-restored at each row time by balancing switches such as transistors 122 and 123.
Phodetectors 13 and 14 of column 2 are coupled to lead 77. The photodetector selected by Row Decoder 108 will provide electrical current depending upon the voltage of the gate of transistor 74 or 94. Transistor 134 has its drain coupled to lead 77, its gate coupled over lead 135 to Voltage V2 and its source coupled to Vss. If photodetector 13 is selected, transistors 74, 76 and 134 form a source follower circuit with the output being on lead 77. Lead 77 is coupled to the input of amplifier 136 via one side of capacitor 137. The other side of capacitor 137 is coupled over lead 138 to an input of amplifier 139 which may be for example a CMOS inverter, to one side of capacitor 140 and to the drains of transistors 142 and 143. The output of amplifier 139 is coupled over lead 145 to the other side of capacitor 140, the sources of transistors 142 and 143 and to the drains of transistors 146 and 147.
Signal BAL is coupled over lead 148 to transistors 122 and 142. Signal BAL bar is coupled over lead 149 to transistors 123 and 143. Signal BAL and BAL bar function to reset amplifiers 116 and 136.
Address signals A3 and A4 are coupled over leads 151 and 152 respectively to column decoder 153. Column decoder 153 functions to select column 1 by way of control signals on leads 155 and 156 or on leads 157 and 158. Signals COLUMN1, COLUMN1 BAR, COLUMN2, AND COLUMN2 BAR are on leads 153-156, respectively. A timing signal TSC is coupled over lead 159 to column decoder 153.
The sources of transistors 126, 127, 146 and 147 are coupled to lead 160 to provide an output terminal from which the output of columns 1 and 2 are multiplexed as a function of column decoder 153.
In operation of photodetector 11, photogate 22 is biased at a high voltage (VDD) during signal integration to create a potential well for the collection of photocharge. The top of this potential well is gated by the transfer gate 26, which is biased at an intermediate voltage below VDD. Photons or radiant energy 6 entering the semiconductor layer 18 under the photogate area converted into electron-hole pairs. Holes are swept to the substrate and electrons are collected in the potential well under photogate 22. At the end of a frame time, the integrated signal charges are ready to be read out, one row at a time.
In operation of photodetector array 10, a row of pixels are selected to be read out by the address signals at Row Decoder 108. The signal levels before readout of a row of pixels begins is shown at time T1 in FIGS. 2A-2G. In FIGS. 2A-2G the abscissa represents time and the ordinate represents a logic level, a 1 or 0.
Referring to FIG. 2A, Signal SELECT1 on lead 110 goes to a logic 1 at time T2 as shown by waveform 164. Signal SELECT1 turns transistors 36 and 76 on. At time T3 as shown by waveform 165, signal RESET1 goes to a logic 1 causing n+ region 28 to be set to a potential of VDD-VTH, where VTH is the threshold voltage of the reset transistor. This reset potential is reflected by the source follower circuit as VPIXEL at capacitor 117 for column 1 and capacitor 137 for column 2. At time T4, as shown by waveform 166 in FIG. 2C, amplifiers 116 and 136 are dc-restored by signal BAL which goes to a logic 1 causing transistors 122 and 148 to be turned on. Complementary signal BAL BAR causes transistors 123 and 143 to be turned on. The voltages on leads 118 and 125 or on 138 and 145 or equalized. At time T5 as shown by waveform 166, signal BAL goes back to a logic 0. The value of signal VPIXEL on leads 37 and 77 which represents the respective reset potential, is stored across the input capacitors 117 and 137, respectively. This reset potential is subsequently subtracted from the signal level, completing the correlated double sampling operation for reset noise removal. Reset noise arises from the kT/C charging noise when the floating n+ region 28 is reset. When transistors 122, 123, 142 and 143 are turned on at time T4, amplifiers 119 and 139 are forced to be biased at the high-low transition point where the gain of amplifiers 119 and 139 which may be inverters is high. At time T6, signal RESET1 goes to a logic 0, thus isolating n+ regions 28 and 68 from n+ regions 32 and 72 respectively which are coupled to Voltage Supply VDD.
At time T7, signal PG is lowered to transfer the integrated photosignal charge (electrons) under transfer gate 26 to n+ region 28. Signal PG is shown as waveform 167 in FIG. 2D. The potential of n+ region 28 will be lowered in proportion to the amount'of signal charge transferred from below photogate 22. The corresponding VPIXEL voltage appears on lead 37 at the input of amplifier 116. The signal VPIXEL on lead 37 is ac-coupled through input capacitor 117 to amplifier 119, thereby subtracting the reset level from the output of amplifier 116 on lead 125. At time T8, signal PG goes back to 0 and charge will again be collected below photogate 22 due to the absorption of radiant energy 6.
At time T9, signal COLUMN1 from column decoder 153 goes to a logic 1 and COLUMN1 BAR goes to a logic 0 causing transistors 126 and 127 to conduct and thereby transfer the output or voltage at the output of amplifier 116 on lead 125 to the common multiplexed output on lead 160. At time T10, signal COLUMN1 goes to a logic 0 and COLUMN1 BAR goes to a logic 1 turning off transistors 126 and 127. COLUMN1 is shown as waveform 168 in FIG. 2E. At time T11, signal COLUMN2 goes to a logic 1 and COLUMN2 BAR goes to a logic 0. Transistors 146 and 147 are turned on to pass the output of amplifier 136 to the multiplexed output on lead 160. If there were n columns, then the output of the amplifier at each column is multiplexed to a single output node by signals COLUMNn to switches which are closed one column at a time. After all outputs are read out at T14 from the multiplexed columns, the outputs of row decoder 108 are a logic 0 till the next frame time, and the next row of pixels, row 2, are selected for output by row decoder 108 by way of signal SELECT2.
Column amplifiers 116 and 136 shown in FIG. 1 may have an input-output transfer function optimized for the application. For example, the input-output transfer function may be sigmoidal with the highest gain designed to be where the input signal is lowest. FIG. 3 is a graph of the output versus input transfer function of amplifier 116. In FIG. 3, the ordinate represents output voltage and the abscissa represents 2 volts minus the X input voltage. X input signal is the light signal. When there is no light, X input equals 0, curve 174 is at 2 volts. The sigmoidal transfer function is shown by curve 174. As shown by curve 174, the gain is smaller when the input signal is larger, thus performing an important dynamic range compression function.
For example, when there is light or an X input, Curve 174 is at 2V-X input. The light signal, X input, is subtracted from 2 volts. Therefore, the gain (slope of the transfer function) is largest at 2 volts-X input equals 2 volts and smallest near 2 volts-X input equals 0 volts.
The gain of amplifier 116 is programmable by changing the ratio of capacitor 120, acting as a feedback capacitor, and the input capacitor 117 such as by a variable capacitor bank where capacitors can be switched in and out. In FIG. 1, the value of capacitor 120 is equal to the value of capacitor 117.
While there has been described and illustrated a photodetector array having circuitry in the array to read out photodetectors with fewer devices and with reduced noise, it will be apparent to those skilled in the art that modifications and variations are possible without deviating from the broad scope of the invention which shall be limited solely by the scope of the claims appended hereto.
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A photodetector array for sensing radiant energy is described incorporating photodetectors, a respective semiconductor region for holding charge and two transistors coupled in series at each pixel, and a column load transistor. An amplifier at the load transistor may provide gain while providing dynamic range compression and a reduction in signal noise due to resetting of the voltage at the semiconductor regions. The invention overcomes the problem of CMOS manufacturing of photodetector arrays and for a simplified circuit per pixel to enable denser arrays and reduced noise.
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RELATED APPLICATIONS
[0001] This application claims priority from copending provisional application Ser. No. 60/208,471, filed Jun. 2, 2000.
GOVERNMENT RIGHTS STATEMENT
[0002] This invention was funded in part by the United States Department of Agriculture under the USDA National Research Initiative Competitive Grants Program (92-37204-8244), USDA Federal Assistance Program Agreement No. 58-3148-5-023 and the National Science Foundation (MCB-9604589). The United States government may have certain rights in the invention.
BACKGROUND OF THE INVENTION
[0003] 1. Technical Field
[0004] This invention relates to determining the genotype of chickens.
[0005] 2. Description of the Background Art
[0006] The poultry breeding business is of major economic importance in the United States and in most parts of the world. Epidemics of viral infectious disease, for example Marek's disease, in flocks raised for meat or eggs can have a devastating effect to this industry, even in modern facilities. Consequently, development of methods to produce breeding stocks of chickens, whether raised for meat or eggs, which are resistant to disease, is commercially very important.
[0007] In chickens, as opposed to most mammals, the particular Mhc haplotypes have readily demonstrated differential influences in the immune response to certain diseases, such as the tumors caused by the highly infectious herpes virus responsible for Marek's disease. Chickens with different Mhc genotypes respond differently to the infectious pathogen of Marek's disease, with potentially deadly consequences to animals possessing a relatively unresponsive Mhc genotype (i.e., two non-protective haplotypes). Determining the Mhc genotype of chickens has therefore become important to the poultry industry, so that disease-resistant strains of chickens can be bred.
[0008] In domesticated fowl, the known Mhc genes are organized into two separate linkage groups, B and Rfp-Y. FIG. 1 provides a schematic map showing the known chicken Mhc genes. The B system comprises polymorphic classical Mhc class I heavy chain, class II beta chain, B-G genes and other genes. The B system has been known as a highly polymorphic blood group system since the early 1940's. Rfp-Y was discovered more recently by DNA hybridizations (Briles et al., Immunogenetics 37:408-414 (1993)) and consists of at least two class I heavy chain genes, three class II beta chain genes, a c-type lectin gene and two additional genes of unknown nature. Miller et al., Proc. Natl. Acad. Sci. USA, 91:4397-4401 (1994); Miller et al., Proc. Natl. Acad. Sci. USA 93:3958-3962 (1996).
[0009] As with the B region, the Rfp-Y gene region is small. At least one Rfp-Y haplotype contains only a single functionally active class I locus. This suggests that disease associations with particular Rfp-Y haplotypes have a similar basis in a small number of loci. In addition, interactions may occur between alleles of the B and Rfp-Y loci. Particular combinations of haplotypes in the two systems therefore may provide optimal disease resistance for a particular disease.
[0010] It has already been observed that when the B system provides intermediate disease resistance to Marek's disease, the influence of Rfp-Y genotype can be significant. Wakenell et al., Immunogenetics 44:242-245 (1996). This influence may be a direct one wherein the Rfp-Y genes compensate in antigen presentation, however additional interactions could occur between loci in B and Rfp-Y. For example, studies of Mhc Class I loci in mice have shown that antigen presenting molecules have a critical role in controlling the activity of natural killer (NK) cells. Signal peptides cleaved from nascent classical class I polypeptides are presented by at least one non-classical class I molecule and recognized by receptors on NK cells, resulting in modulation of NK cell activity. Natural killer cells are critical in eliminating infected cells in which class I molecule expression has been down-regulated by the infecting pathogen. Having the capacity to detect B and Rfp-Y haplotypes in commercially bred poultry provides a means by which immune responses can be optimized.
[0011] In the chicken, the role of particular Mhc haplotypes in disease resistance has been extensively investigated. The influence of the genotype of the Mhc B system and resistance to certain diseases in chickens, for example, Marek's disease, has been documented by several authors. See Hanson et al., Poult. Sci. 46:1268 (1967); Briles et al., Science 195:193-195 (1977); Briles et al., Science 219:977-979 (1983); Longenecker et al., Immunogenetics 3:401-407 (1976); Dietert et al., Crit. Rev. Poult. Biol. 3:111-129 (1991); Kaufman et al., Immunol. Rev. 167:101-117 (1999). Genotyping of the B complex of chickens, however, has focused mostly on particular lines of White Leghorn birds, a breed raised primarily for egg production. Alloantisera used to determine B haplotypes in particular lines of egg-producing chickens do not work well for B haplotyping in other lines of chickens. This is especially true for those lines used in the production of chickens raised for meat which are genetically somewhat distant from layer lines.
[0012] Though the immune response in chickens to Marek's disease and other viral pathogens is strongly influenced by B complex genotype, other alleles at other loci, including the Rfp-Y gene cluster, perhaps the NK region and other more poorly characterized regions as well, influence Marek's disease resistance. See Brown et al., Avian Dis. 28:884-899 (1984); Vallejo et al., Anim. Genet. 28:331-337 (1997); Bumstead, Avian Pathol. 27:s78-s81 (1998); Kaufman et al., Avian Pathol. 28:s82-s87 (1998); Bumstead, Rev. Sci. Tech. 17:249-255 (1998); Yonash et al., Anim. Genet. 30:126-135 (1999). Rfp-Y haplotypes differentially influence disease resistance and immunity in chickens. For example, Pharr et al. showed, in chickens of Cornell line N, that with birds homozygous for B system haplotype, skin graft rejection was greater and occurred more quickly when donor and recipient were mismatched for Rfp-Y than when they were Rfp-Y compatible. Pharr et al., Immunogenetics 45:52-158 (1996). Additionally, there is varied evidence for the ability for Rfp-Y differences to stimulate lymphocyte proliferation in vitro (Pharr et al., Immunogenetics 45:52-58 (1996); Juul-Madsen et al., Immunogenetics 45:345 (1997)), indicating that alloresponses to Rfp-Y may be induced.
[0013] The products of Rfp-Y genes have a structure similar but not identical to classical class I molecules. The sequence variability inherent in the Rfp-Y class I molecules themselves is sufficient to inherently elicit this type of allogeneic response, but alternatively these molecules could present some form of polymorphic antigens that serve as a minor histocompatibility antigen and produce the described histocompatibility effect. The Rfp-Y loci may be important in providing molecules that supplement the apparently less than comprehensive antigen presentation provided by the B system loci. Mhc-like genes located outside classical Mhc gene regions are implicated in a number of immune response functions in mammalian species, including selection of T-cell population during development. Adachi et al., Proc. Natl. Acad. Sci. (USA) 92:1200-1204 (1995).
[0014] The previous work of Wakenell et al. indicates that Rfp-Y haplotypes influence resistance to the commercially important Marek's disease in the chicken. Studies of Rfp-Y influence on Marek's disease virus challenge have produced results indicating that Rfp-Y haplotype affects susceptibility to infection in different B complex backgrounds. Wakenell et al., Immunogenetics 44:242-245 (1996). In this study, data comparing incidence of Marek's disease tumors in chickens carrying three different Y system genes showed that the Rfp-Y system exerts an effect on Marek's disease resistance and that the influence of Rfp-Y haplotypes in some combinations may be quantitatively similar to that of the B-F region. See Wakenell et al., page 244. Some conflicting data that has been reported might be due to the particular B and Y complex interactions either accentuating or masking the Rfp-Y effects. See Vallejo et al., Anim. Genet. 28:331-337 (1997).
[0015] Genes within B and Rfp-Y both have a demonstrated influence in resistance and susceptibility to a number of diseases, including virally-induced tumors, bacterial infections and infections with protozoan parasites. See, for example, Briles et al., Science 195:193-195 (1977); Briles et al., Immunogenetics 20:217-226 (1984); Longenecker et al., Immunogenetics 3:401-407 (1976); Kaufman et al., Hereditas 127:67-73 (1997); Wakenell et al., Immunogenetics 44:242-245 (1996); Vallejo et al., Anim. Genet. 28:331-337 (1997); Lamont, Rev. Sci. Tech. 17:128-142 (1998); Caron et al., Poult. Sci. 76:677-682 (1997); Thacker et al., J. Virol. 69:6439-6444 (1995); Uni et al., Br. Poult. Sci. 36:555-561 (1995); Bacon et al., J. Hered. 86:269-273 (1995); Hlozanek et al., Virology 203:29-35 (1994); Schat et al., Poult. Sci. 73:502-508 (1994); Nakai et al. Avian Dis. 37:1113-1116 (1993); Lamont et al., Immunogenetics 25:284-289 (1987); Cotter et al., Poult. Sci. 77:1846-1851 (1998).
[0016] There are additional studies reported in the literature describing the influence of Mhc haplotype in many poultry diseases, for example the regression of Rous sarcoma virus induced tumors, Marek's disease, infectious laryngotracheitis and coccidiosis. See Yoo et al., Br. Poult. Sci. 33:613-620 (1992); Poulsen et al., Poult. Sci. 73 (Suppl. 1):108 Abstr. (1994); Poulson et al., Poult. Sci. 77:17-21 (1998); Clare et al., Immunogenetics 22:593-599 (1985). Since the association of Mhc haplotype with disease resistance in chickens has been demonstrated, the haplotyping methods described below may be used to select for chickens genetically resistant to a variety of diseases.
[0017] One of the most important diseases of poultry, in commercial terms, Marek's disease, is caused by a highly contagious herpes virus that induces T-cell lymphomas in chickens. The virus exists in poultry-breeding countries throughout the world and is responsible for tremendous losses to the industry. Because of the strong Mhc B influence on survival of infection with Marek's disease virus, many modern commercial chicken breeders select for or are at least aware of the Mhc B types in their commercial lines. Breeders generally have not been able to test for Rfp-Y genotypes, however.
[0018] Vaccination is very effective in reducing losses from Marek's disease, but vaccine breaks do occur and there is evidence that new, more virulent forms of Marek's disease virus appear periodically in vaccinated flocks. Importantly, Mhc haplotypes also influence the efficacy of vaccination in commercial flocks, see Bacon et al., Poult. Sci. 73:481-487 (1994); Bacon et al., J. Hered. 86:269-273 (1995); Bacon et al., Avian Dis. 38:65-71 (1994). Genetic resistance is an important adjunct to vaccination in the prevention of Marek's disease in chickens. Therefore the strategies of selection for beneficial Mhc haplotypes and vaccination may be used together to optimize flock performance. Mhc haplotyping according to this invention may also be used to test for newly-recognized resistant haplotypes so they may be introduced into flocks.
[0019] Another disease of consequence in commercially raised chickens is coccidiosis. Coccidiosis is a protozoal disease of poultry and other birds that results in diarrhea, enteritis and weight loss. Coccidiosis occurs everywhere that poultry are raised in large numbers. There are seven valid species of chicken coccidia ( Eimeria acervulina, E. brunetti, E. maxima, E. mitis, E. necatrix, E. praecox and E. tenella ) that vary in their pathogenicity. Infections with the causative organisms occur most often in young, rapidly growing birds. Administration of anticoccidial drugs in recent years have reduced some losses, however drug resistant forms of coccidia appear to be developing since losses now are increasing despite the extensive use of drugs.
[0020] This phenomenon has led to interest in developing alternative means of infection control of this disease based in immunity. Mhc haplotype has been shown to influence resistance, susceptibility and immunity to Eimeria. See for example, Caron et al., Poult. Sci. 76:677-682 (1997), Brake et al., Infect. Immun. 65:1204-1210 (1997); Nakai et al., Avian Dis. 37:1113-1116 (1993). Mhc haplotype differences are correlated with differences in caecal lesion scores and weight gain during infection. Also, just as with Marek's disease, Mhc haplotype influences the effectiveness of immunizations. Methods of chicken haplotying therefore can be used advantageously to select birds resistant to coccidiosis or with improved immune response to Eimeria ssp. upon vaccination.
[0021] Another acute viral disease of commercial importance is laryngotracheitis. This disease currently is managed by strict separation of susceptible flocks and by vaccination. Particular Mhc B haplotypes have been found to differ significantly in their influence in laryngotracheitis. As with Marek's disease, laryngotracheitis is caused by a herpes virus and immune responsiveness apparently is a component of susceptibility to this disease as well. Again, as with Marek's disease, Mhc haplotype influences the efficacy of vaccination against laryngotracheitis (birds of some haplotypes require higher dosage of vaccine to achieve protection). Poulsen et al., Poult. Sci. 73 (Suppl. 1):108 Abstr. (1994); Poulson et al., Poult. Sci. 77:17-21 (1998).
[0022] Genes located within chicken Mhc regions have significant effects on the immune response to pathogens that can be detected experimentally. For example, the capacity of chickens to regress tumors caused by avian leukosis virus is associated with the capacity of T cells to respond to the presentation of Mhc restricted antigen. Thacker et al. J. Virol. 69:6439-6444 (1995). A number of the standard and recombinant B haplotypes have been categorized as either progressor or regressor haplotypes. Brown et al. Immunogenetics 19:141-147 (1984); Collins et al. Poult. Sci. 64:2017-2019 (1985); Taylor et al. Anim. Genet. 19:277-284 (1988); Lukacs et al. Poult. Sci. 68:233-237 (1989); Aeed et al. Anim. Genet. 24:177-181 (1993); White et al. Poult. Sci. 73:836-842 (1994). In the Rous sarcoma virus experimental system, immunity is v-src-specific. Gelman et al., Cancer Res. 53:915-920 (1993); Plachy et al., Immunogenetics 40:257-265 (1994). There is evidence that B haplotype is also associated with shedding of avian leukosis group-specific antigen and hence may influence susceptibility to post-hatching infection from other infected birds. Yoo et al., Br. Poult. Sci 33:613-620 (1992).
[0023] Further associations between Mhc haplotype and resistance to two bacterial pathogens—fowl cholera and salmonella are reported. Lamont et al., Immunogenetics 25:284-289 (1987); Cotter et al., Poult. Sci. 77:1846-1851 (1998). These reports demonstrate the importance of Mhc haplotype to immunity in chickens against several commercially important diseases and to the important experimental model, Rous sarcoma virus, and suggest that genetic selection for particular Mhc haplotypes is valuable to breeders for the production of both individuals and flocks that are resistant to numerous diseases.
[0024] Selection for B haplotypes providing resistance to Marek's disease is performed by a number of companies breeding chickens for the production of eggs. Generally, selection is done on the basis of the results of hemagglutination assays using alloantisera that have been developed for particular breeding lines within the company's flocks. These serological typing methods can be applied to birds within a population once appropriate serological reagents have been developed, however alloantisera made in one population are usually not useful to type other populations. See Li et al., Immunogenetics 49:215-224 (1999). Because most of the alloantisera currently available were prepared for chickens bred for eggs (primarily the White Leghorn breed), there are few reagents available for haplotyping other breeds of chickens.
[0025] Development of appropriate alloantisera is a lengthy procedure, generally requiring several years. In addition, the genetic background of the birds, including at least some information with respect to other blood group systems, should be known before the alloantisera are produced. This requirement poses a major disadvantage. In the past, the genetics of birds used as donors and recipients in the immunizations to produce alloantisera have been surmised by initial approximations of the genetic differences using alloantisera from other flocks. The alloantisera specific for a particular flock must be made by reciprocal immunizations between sire and dam in fully pedigreed stock, and then tested by hemagglutination assay among the fully pedigreed progeny of the birds that served as donors and recipients in the immunizations. Cross-reactivity among B haplotypes is commonly encountered, necessitating appropriate adsorptions of the sera to enhance their specificity for the individual Mhc B haplotypes. Because any alloantiserum potentially contains antibodies to a number of polymorphic cell surface markers, considerable care must be taken in typing poorly characterized flocks. Accurate results require considerable attention to detail.
[0026] The existing serological reagents from egg-producing chickens are not useful in other chicken breeds. Mhc marker assisted selection for Marek's disease resistant broiler chickens is not performed routinely, in part because of the lengthy effort needed to develop typing methods based on alloantisera and in part because of the breeding methods used to maintain broiler breeder stock. Therefore, a simple method for Mhc haplotyping for these birds is not currently generally available. No serological reagents exist for the Rfp-Y system in any breed of chicken. The B system and the Rfp-Y system of chickens of all breeds, even those not belonging to the White Leghorn breed, can be studied advantageously using the inventive methods and probes, allowing Mhc marker assisted selection to be applied in selecting for additional disease resistance in breeding stock.
[0027] DNA-based typing methods, although currently more expensive on a per test basis, have obvious advantages in that nucleotide probes can be used to determine Mhc haplotypes in flocks without the enormous investment of time and labor required to make alloantisera. One such method relies on the patterns of B-G gene restriction fragments revealed in genomic DNA digested with a restriction enzyme and analyzed by Southern hybridization with nucleic acid probes for the B-G genes. See Miller, U.S. Pat. No. 5,451,670. An advantage of this type of approach is that prior knowledge of gene sequences is not necessary. Another method relies on gene restriction fragment patterns revealed in genomic DNA digested with several restriction enzymes and analyzed by Southern hybridization with non-system-specific nucleic acid probes for the B-F and B-L genes. See Lamont, S. J. et al., Poult. Sci., 69:1195 (1990). Yet another similar method is based on hybridization of oligonucleotide probes specific for known sequences in the various alleles of the B system class I gene. See Heath et al., Poult. Sci. 73(Suppl 1):5 (1994).
[0028] Various applications of Southern hybridization with B system probes have been reported in the literature. See Chausse et al., Immunogenetics 29:127-130 (1989); Goto et al., Immunogenetics 27:102-109 (1988); Miller et al., Immunogenetics 28:Z374-379 (1988); Briles et al., Immunogenetics 37:408-414 (1993); Pharr et al., J. Hered. 6:504-512 (1997). The B-G gene probes which are useful in ascertaining B haplotypes because of their close linkage to B class I and class II loci are often sufficient in known stocks of birds for the assignment of B haplotype. The B-F and B-L probes are useful in revealing polymorphic restriction fragment patterns, but they show cross hybridization (recognition) with genes both in B and Rfp-Y gene clusters since each of the B-F and B-L probes were developed without knowledge of sequence differences in the B and Rfp-Y genes.
[0029] Because the class I and class II genes in Mhc B and Rfp-Y are fairly closely related, probes for the B system crosshybridize to varying degrees with Rfp-Y genes. It therefore is difficult to use these methods to type birds for polymorphisms in either system in the presence of polymorphisms that are contributed by the other system. For this reason, the probes initially used to identify the Rfp-Y cluster were B system probes able to hybridize to genes in both the Rfp-Y and B gene clusters. Because of the crossreactivity, these types of tests often cannot provide useful Rfp-Y data unless analysis is performed on fully pedigreed families of birds and B-G typing is also performed. Otherwise it is not possible to distinguish which restriction fragments result from each system. Indeed, the presence of Rfp-Y was only found because fully pedigreed animals happened to be the subject of a study with another objective.
[0030] DNA-based Mhc typing based on specific sequences may be used, however one must have some sequence data for genes within each haplotype in the population to be tested. This requirement is a major stumbling block to development of an easy, comprehensive haplotyping method for B and Rfp-Y system genes. It is difficult, at least initially, to obtain complete haplotype information about a particular bird using these methods without making sequence determinations for each allele at each locus chosen to represent the entire haplotype.
[0031] The use of a technique known as polymerase chain reaction, single-stranded conformational polymorphism (“PCR-SSCP”) has been proposed to study the expression of genes in non-erythroid tissues. Miller, M. M. and Goto, R. M., Avian Immunology in Progress , Tours (France), Aug. 31-Sep. 2, 1993, Ed. INRA, Paris 1993 (Les Colloques, No. 62); Zoorob et al., PCT/FR98/02501. In this method, short segments of genes of interest are amplified using the PCR. The PCR products are then heat denatured and applied to a non-denaturing polyacrylamide gel. The single-stranded fragments of the heat-denatured DNA fragments assume secondary conformations determined by their sequences and migrate differently in the polyacrylamide gel during electrophoresis, producing a pattern (or fingerprint) representative of the sequences within the genome in the region of amplification. For this method, oligonucleotide primer sets that hybridize to conserved sequence sites surrounding the polymorphic regions must be developed for the different alleles to be typed. Therefore, a certain amount of knowledge regarding the structure of the genes to be studied is required. PCT application PCT/FR98/02501 discloses methods of detecting Mhc genes in birds such as chickens which are related to resistance to virally-induced tumors, for selection of animals having a desired genotype. Specific nucleic acid probes are disclosed which are able to discriminate between genes of the B and Rfp-Y systems.
[0032] Currently, there are no commercially available tests to determine the haplotype in the Rfp-Y system. There are no alloantisera. Consequently, a test which would allow breeders, researchers, and others to rapidly determine the haplotype of birds using relatively straightforward techniques is needed. An ideal test would be quick, simple to perform, and avoid the need for specialized equipment beyond that commonly found in a molecular biology laboratory. The test would not require alloantisera which might not be available for use in all birds or detailed knowledge of the genetics of the birds to be tested. Such a test which could determine the haplotype in the Rfp-Y system as well as the B system using a single set of reagents for each system would be highly desirable, and could be used to aid in breeding birds with increased resistance to disease.
SUMMARY OF THE INVENTION
[0033] Accordingly, the present invention provides the probes of SEQ ID NO: 1 and 2, and probes which contain at least about 17 consecutive nucleotides of these sequences and are about 17 to about 1,000 nucleotides in length. Preferred probes are about 100 to about 1,000 nucleotides in length. Most preferred probes are those of SEQ ID NOS: 1 and 2. Probes which are fragments of SEQ ID NOS: 1 and 2 are contemplated by the invention, from about 17 nucleotides to one nucleotide less than the entire sequence. Probes which are at least about 70% homologous, or preferably at least about 90% homologous to SEQ ID NOS: 1 and 2 are also provided. Because of the nature of DNA hybridization, higher degrees of homology are required for shorter probes; e.g., only a perfect match or a single nucleotide mismatch is preferred for probes of minimum (about 17 nucleotides) length.
[0034] The invention provides methods for breeding chickens to produce disease-resistant offspring by selecting a disease-resistant chicken for mating using these probes. The method involves providing a genomic DNA sample from at least one chicken, digesting the sample with one or more restriction endonucleases to obtain restriction fragments and resolving the restriction fragments, preferably by electrophoresis. The resolved fragments are then optimally transferred to one or more hybridization membranes and optionally immobilized there. The resolved fragments are then incubated with a labeled probe as described above such that the probe hybridizes. Unhybridized probe is removed and an image of the labeled hybridized probe is created, to form a restriction fragment pattern. From this restriction fragment pattern, the Mhc genotype of the chicken providing the DNA sample is determined. If desired, the probe can be stripped and a second probe used in the same manner to create a second restriction fragment pattern.
[0035] In a preferred embodiment, the resolved restriction fragments from the genomic DNA sample of a single bird are probed twice, once with a probe specific for the Rfp—Y system and one specific for the B system of the chicken Mhc. Most preferably, the probes of SEQ ID NOS: 1 and 2 are used sequentially or on parallel samples of genomic DNA from the same chicken. Once the Mhc genotype of a chicken has been determined, the genotype is correlated with disease-resistance and a chicken having an Mhc genotype which correlates with disease-resistance is selected for mating. The selected chicken is mated with a second chicken of opposite gender. Preferably, the second chicken has also been selected for a Mhc genotype correlating with disease resistance according to the invention. The invention also provides methods for selecting chickens which are disease-resistant as described above, and methods for determining the Mhc genotype of chickens as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] [0036]FIG. 1 provides a schematic map of chicken Mhc genes.
[0037] [0037]FIG. 2 provides an alignment of the Y-FVw*7 (SEQ ID NO: 5) and B-FIV*12 (SEQ ID NO: 6) gene sequences. The “-” indicates sequence identity. The “/” indicates a gap inserted to optimize sequence alignments.
[0038] [0038]FIG. 3 depicts the alignment of the deduced amino acid sequences of Y-FVW*7 (SEQ ID NO: 3) and B-FIV*12 (SEQ ID NO: 4) to illustrate regions of greatest sequence difference between the B and Rfp-Y class I loci. The “-” indicates sequence identity. The “/” indicates a gap inserted to optimize sequence alignments.
[0039] [0039]FIG. 4 provides the sequence of the 178/179f probe for B class I genes (SEQ ID NO: 2).
[0040] [0040]FIG. 5 provides the sequence of the 163/164f probe for Rfp-Y class I genes (SEQ ID NO: 1).
[0041] [0041]FIG. 6 shows three Southern hybridizations using the same filter containing BglI-digested DNA from two fully pedigreed families sharing the same sire hybridized successfully with (A) a prior art B system class II probe (B-LβII); (B) the Rfp-Y class I specific probe 163/164f and (C) the B system class I specific probe 178/179f.
[0042] [0042]FIG. 7 is a Southern hybridization showing sequence variability in the Rfp-Y class I genes in nine different Rfp-Y haplotypes revealed by the 163/164f probe.
[0043] [0043]FIG. 8 shows two Southern hybridizations of the same filter containing Bgl-I digested DNA from genetically related birds hybridized (A) with the 163/164f probe and (B) with prior art probe B-LβII.
DETAILED DESCRIPTION OF THE INVENTION
[0044] The two B class I loci, represented by B-FI*12 and B-FIV*12, are highly similar to each other (94% identity in nucleotide sequence). The two Rfp-Y class I genes, represented by Y-FVw*7 and YFVIw*7, also are nearly identical (94%) with the exception of a large hexanucleotide repeat sequence (48 copies of the hexanucleotide GGGCTG (SEQ ID NO: 11) in the exon 1 sequence of Y-FVIw*7. Because the two loci in each system are very similar to each other, aside from this repeat, the Y-FVw*7 and B-FIV*12 were chosen as representative for the loci in each system and used in sequence analysis.
[0045] Because of the time-consuming process required to determine the Rfp-Y genotype of a bird using the cross-hybridizing B probes, and the increasing use of haplotyping by Southern hybridization both for experimental and commercial purposes, the sequences of the Rfp-Y and B class I loci (represented here by Y-FVw*7 and B-FIV*12; see FIG. 2) were aligned and examined for regions where the loci were most divergent, with the goal of developing system-specific probes. The alignments compared in Table 1 demonstrate that the genes generally share greater similarity at their 5′-ends and mid-sections, especially in exon sequences, and diverge more at the 3′-end.
TABLE 1 Sequence Similarity Comparisons Between Different Segments of the Y-FVw*7 and B-FIV*12 Genes Gene DNA Amino acid region/domain Similarity Similarity Y-FVw*7 vs. Length (bp) Index 1 Index 2 B-FIV*12 Y-FVw*7 B-FIV*12 (S.I.) (S.I.) 5′UT 124 162 56 — Ex1/sp 63 66 72 56 IN1 126 117 66 — Ex2/α1 261 264 66 49 IN2 245 226 44 (58) 3 — Ex3/α2 276 273 59 64 IN3 95 103 68 — Ex4/α3 273 273 86 77 IN4 80 71 65 — Ex5/TM 102 108 59 51 IN5 114 110 57 — Ex6/cy1 33 33 49 54 IN6 157 159 38 — Ex7/cy2 33 33 NS 46 IN7 185 154 58 — Ex8/cy3 18 18 NS (67) 4 67 3′UT (to 127 155 51 — poly A signal) 163/164f vs. 626 675 41 — 178/179f
[0046] Because the 3′-ends of the B and Rfp-Y loci were found to differ most extensively by both empirical and sequence comparisons, the two system-specific probes, 163/164f for Rfp-Y class I genes and 178/179f for B class I genes, were made corresponding to the respective 3′ regions of the Rfp-Y and B-E loci. These two probes have a similarity index of 41 (see Table 1) and show distinct regions of unique sequence in a Martinez/Needleman-Wunsch DNA alignment.
[0047] [0047]FIG. 3 depicts the deduced amino acid sequences of Y-FVw*7 (SEQ ID NO: 3) and B-FIV*12 (SEQ ID NO: 4), aligned to illustrate regions of greatest sequence difference between the B and Rfp-Y class I loci. It is evident in FIG. 3 that the YFVw*7 and BFIV*12 genes share a great deal of identity in deduced amino acid sequence, however there are two regions where the amino acid sequences differ significantly. The α1 domain sequences diverge and are inherently polymorphic within both B and Rfp-Y loci. The latter half of the transmembrane domain and the three small cytoplasmic domains display significant divergence as do the intervening introns (see FIG. 2 and Table 1). The sequences of Y-FVw*7 and B-FIV*12 were obtained from the sequence of cosmid clone c17 and from Genbank M31012, respectively. Because the divergence is greatest in the 3′ region of the genes (the latter half of the exon corresponding to the transmembrane domain and the exons of the cytoplasmic domains, intervening introns and 3′-untranslated regions) this region was chosen for the design of probes specific for the class I loci in each system.
[0048] Based on alignments revealing these areas of divergence, primer sets were designed to specifically amplify those regions in the Mhc B (primer 178(OLBF4TM); GGTGTTGGATTCATCATCTAC; SEQ ID NO: 7 and primer 179(RVBF43U); GCATAACAGTCAGCATAGGAA; SEQ ID NO: 8) and Rfp-Y (primer 163(OLYFVTM); CGCAGCCCAACCTGATTCCCA; SEQ ID NO: 9 and primer 164(RVYFV3U); TGTCAGCCCGAGGAGATGCAG; SEQ ID NO: 10) class I genes. Using the PCR, the 178/179 and 163/164 primer sets hybridize specifically to the genes in each gene cluster and amplify from the genomic DNA regions of the genes which are maximally different between the B region and the Rfp-Y region.
[0049] Thus, a probe was designed and cloned for each system which would be able to hybridize specifically to genes and gene fragments of each system without cross-hybridizing with the genes of the other system. The amplified and cloned regions encompass three exons corresponding to the cytoplasmic tail, surrounding introns and portions of the 3′-untranslated region. Clones from these regions form the probes for each system, termed the 178/179f (B system) probe (SEQ ID NO: 2) and the 163/164f (Rfp-Y system) probe (SEQ ID NO: 1). See FIGS. 4 and 5. The substrate DNA for production of the 163/164f probe was genomic DNA from a bird homozygous for the Y-F*w3 haplotype. While primer set 163/164 was used to produce the 163/164f probe, the 163/164f probe is shorter than the full expected sequence. For reasons that are not known, the fragment cloned from the 163/164 primer set PCR amplification was truncated at the 5′ end. It is 120 nucleotides shorter than expected based on the primer 163 priming site. To have essentially the mirror image probe, the 178 priming site in the B-FIV sequence was located at a position nearly equivalent to the 5′ start of 163/164f clone.
[0050] When tested in Southern hybridizations using DNA from fully pedigreed families for which the Mhc B and Rfp-Y types had been previously determined, the 178/179f probe was found to be specific for B class I genes and the 163/164f probe was found to be specific for Rfp-Y class I genes, confirming the specificity of each probe. Southern blot analysis to show the specificity of the probes was performed as follows. Samples containing 10 ug of genomic DNA were digested with a restriction enzyme. PstI, BglI, TaqI, PvuII, EcoRI and BamHI were used. The digest was subjected to electrophoresis in 0.8% agarose gels, and transferred to a non-charged hybridization membrane. The resolved fragments were stabilized in the membrane by UV-crosslinking and hybridized to each of the 178/179f and 163/164f probes. The probes (25-50 ng) were labeled by random priming with α 32 P-dCTP.
[0051] Hybridizations were carried out overnight in a rotating hybridization tube at 65° C. with 1-2×10 6 cpm/ml 32 P-labeled probes in the presence of 5× SSPE (0.75 M NaCl, 0.05 M NaH 2 PO 4 , 5 mM EDTA), 5× Denhardt's solution (1 g/l Ficoll 400, 1 g/l polyvinylpyrrolidone, 1 g/l bovine serum albumin (Pentax Fraction V)), 100 pg/ml denatured salmon sperm DNA and 1% SDS. At this temperature and concentration of SSPE, hybridization is stringent so that the labeled probes will hybridize essentially only to identical or nearly identical sequences. Following the overnight hybridization, the membranes were washed at 65° C. at a lower salt concentration (75 mM NaCl, 7.5 mM sodium citrate with 1% SDS) to remove non-specifically adhering probe.
[0052] Results demonstrated that each probe showed no cross reactivity to the other gene system. This is illustrated in FIG. 6, wherein PstI-digested DNA samples from the fully pedigreed A186 and B186 families were probed with 163/164f (FIG. 6B) and 178/179f (FIG. 6C). The patterns of the same DNA samples when hybridized with a prior art probe, full-length B class I probe (BF10) recognizing class Iα genes in both Rfp-Y and B is provided for comparison in FIG. 6A. The observed polymorphic restriction fragments reflect the genotypes in Rfp-Y and B respectively as previously determined. Miller et al., Proc. Natl. Acad. Sci. USA 91:4397-4401 (1994). There are no bands shared in common between the two patterns that represent Rfp-Y and B as revealed by the inventive probes.
[0053] The 163/164f probe for Rfp-Y genes was further tested for the ability to resolve polymorphic restriction fragment patterns in Southern hybridizations with additional Rfp-Y haplotypes to explore the potential range of utility of this probe. Genetic material from nine chickens, each possessing a different previously determined haplotype, was examined by Southern hybridization using the 163/164f probe. The probe was able to clearly resolve nine unique Rfp-Y class I TaqI restriction fragment patterns for the nine birds. (See FIG. 7.)
[0054] Interestingly, the number of TaqI and BglI restriction fragments is different among the haplotypes. For example, in FIG. 7 only two restriction fragments were revealed in haplotypes Yw*l and Yw*7, but over ten fragments were found in haplotypes Yw*4 and Yw*6. Similar differences were found in the number of BglI restriction fragments (FIG. 8A). Similar procedures using the 178/179f probe for Mhc B class I genes confirmed this probe's ability to distinguish genetic variability in the B region (data not shown). Polymorphism in the B region, however, exists in other locations besides those recognized by the 178/179f probe (see, for example, FIG. 6A compared to FIG. 6C). Therefore, this probe reveals only a portion of the B class I genetic variability in an outbred population of birds. For example, one might find that several different B types defined by other methods would share the same restriction fragment pattern as revealed by the 178/179f probe with the most commonly used restriction enzymes.
[0055] Haplotyping may be performed with either of the probes of SEQ ID NO: 1 or SEQ ID NO: 2 individually or with both probes. Probe fragments and homologous probes also may be used as discussed above. Probes based on SEQ ID NOS: 1 and 2 but having non-hybridizing tails also are useful. Additional probes may also be used alongside the inventive probes if desired. Those of skill in the art will appreciate many variations of methods which are suitable. Chickens of any breed or type may be haplotyped or selected for breeding using the inventive probes. For example, the described methods may be applied to egg-laying stock, meat-type birds and dual purpose breeds, derivatives from these or any breed.
[0056] An advantage of these methods is that they can be applied to any chicken regardless of the breed, without knowledge of the exact nucleotide sequences in the polymorphic regions of the DNA being tested. The methods and probes can be used in the analysis of flocks for which no Mhc haplotype information exists and in many cases distinguish more different genotypes than existing prior art probes. In addition, the methods are easy to use and require only standard equipment for molecular biology. The methods can also be used initially to define the B and Rfp-Y genetics of a bird population to assist in the preparation of alloantisera for haplotyping.
[0057] Chickens are haplotyped using the inventive method according to the following general scheme. DNA is purified from a tissue sample from each individual bird to be tested. Genomic DNA samples for testing may be purified according to any convenient method which is known in the art and may be purified from any suitable tissue. Blood samples are conveniently used, however any tissue, such as wattle or comb tissue is suitable as well.
[0058] The DNA is cut into restriction fragments with one or more restriction endonuclease. BglI, PvuII, PstI, BamHI, EcoRI and TaqI are often used, however any restriction endonuclease or combination of restriction endonucleases which is suitable may be used. Haplotyping may be performed sequentially or in parallel with different endonucleases or combinations of endonucleases. Generally, enzymes that are intermediate in the frequency of cutting are suitable alternatives. Those of skill in the art are well aware of the variety of restriction enzymes available and their properties and thus are able to select any suitable enzyme. The restriction fragments are then resolved. Agarose gel (0.8-1.0%) electrophoresis is conveniently used. The electrophoresis may be accomplished on a slab gel, a tube gel or capillary electrophoresis may be performed. Generally, any method of separation is compatible with the use of these probes so long as the technique used is sufficient to resolve the restriction fragments and allows for hybridization of the probes.
[0059] The resolved fragments then most typically are transferred to and immobilized on a hybridization membrane. If it is desired to haplotype a sample with more than one probe, the restriction fragments may be transferred from the gel to multiple hybridization membranes, or alternatively, the DNA sample may be resolved in two lanes of the same or separate gels and then transferred to hybridization membrane(s). Filters may also be hybridized with one probe, the probe stripped, and a second hybridization carried out with an additional probe. A variety of techniques are well known by those of skill in the art and are contemplated for use with this invention.
[0060] After transfer, the restriction fragments may be stabilized in the hybridization filter if desired using any suitable technique. Exposure to UV light may be used, however any convenient method is contemplated for use with these methods. Alternative approaches also can be applied to reveal the resolved restriction fragments. For example, hybridizing the resolved DNA fragments with labeled probe may be done in the agarose gel, without transfer to a membrane. For this technique, fragments of the described probes are preferred, including synthetic oligonucleotides probes as small as 17 nucleotides.
[0061] The hybridization membranes containing the immobilized DNA fragments are then incubated with a labeled probe, according to known methods. A 32 P label is most conveniently used, however other labels, both radioactive and non-radioactive, are available. Probes may be labeled with non-radioactive fluorescent tags (for example with ECF random prime labeling using products such as those available from Amersham Pharmacia Biotech) and detected in an imaging device such as Storm® fluorescence scanning system (Molecular Dynamics). Alternatively, probes can be labeled with chemiluminescent tags and visualized on film (for example, digoxigenin (DIG)-II-dUTP can be used and detected with an anti-DIG-alkaline phosphatase conjugate (Fab fragments) in highly specific immunoassays and visualized on film using the chemiluminescence substrates CSPD® or CDP-Star™ (Roche Molecular Biochemicals).
[0062] Incubation is performed under conditions which promote hybridization. Skilled artisans are well acquainted with such techniques and routinely adjust the incubation conditions for hybridization of probes so that optimal binding is achieved. Generally, stringent conditions provide good results. For 32 P labeled probes, these hybridizations are generally carried out in buffer containing 5× SSPE and 5× Denhardt's solution with 1% SDS and 100 μg/ml denatured salmon sperm DNA at 65° C. for 16 hours. The excess probe is removed by suitable washes (such as, for 32 P-labeled probes, 0.5× SSC containing 1% SDS for one hour at 65° C., followed by a brief (1-2 minute) room temperature wash in 0.5× SSC to remove excess SDS), and an image of the bound labeled probe is created. Images from 32 P-labeling may be collected on film or in a phosphor imaging device such as PhosphorImager™ (Molecular Dynamics/Amersham Pharmacia).
[0063] Alternatively, suitably specific conditions could be provided by hybridizing at 42° C. in the presence of 50% formamide (a compound that minimizes mismatched hybridization). Skilled works are familiar with adjusting conditions for hybridization and washing to achieve optimal results and such is considered routine.
[0064] Probes of the invention include the probe of SEQ ID NO: 1, SEQ ID NO: 2, probes with substantial homology (at least about 70%, or preferably at least about 90%) to SEQ ID NOS: 1 and 2 or fragments of such sequences. Probes having a longer sequence but including the above sequences may also be used, including sequences comprising adjacent regions of the gene of origin or its alleles. Generally, useful probes are limited by the similarity that exists between the class I genes in the B and Rfp-Y systems. Therefore, for example, it would be difficult to extend the length of the probes to include the entire transmembrane domain encoding exon and most of the more 5′- sequences since these regions generally show a high overall similarity index between the genes in the B and Rfp-Y systems. See Table 1.
[0065] Use of longer probes that encompass regions which are highly similar in the B and Rfp-Y genes would reveal mixtures of polymorphic and non-polymorphic fragments presenting allelic variabilities in both systems (as illustrated in FIG. 6A), making it more difficult to assign genotypes in either system with certainty. Extending the length of the probes to include more 3′- regions of the genomes is expected to be acceptable provided that the sequences in the more 3′- regions are sufficiently different between B and Rfp-Y loci and that the region contains polymorphic sequences within each system. Probes having non-hybridizing tails may be used, if desired, with the inventive methods. Fragments of the sequences SEQ ID NOS: 1 and 2 represented by oligonucleotides of as few as about 17 nucleotides to DNA fragments up to one nucleotide fewer than the entire sequence are contemplated for use with the invention and such fragments may be modified with non-hybridizing tails. Preferred probes are about 17 to about 1,000 base pairs, but most preferred probes are about 100 base pairs to about 1,000 base pairs in length and include at least 17 consecutive base pairs of the sequence of SEQ ID NOS: 1 or 2.
[0066] Probes which are substantially homologous to the sequences of SEQ ID NOS: 1 and 2 also are useful in haplotyping chickens according to the invention. Probes (and probe fragments) having insertions, deletions or substitutions may be useful so long as the probe used in able to hybridize with the genomic DNA restriction fragments of the appropriate system. Generally, useful probes have greater than about 70% homology and preferred probes have greater than about 90% homology to SEQ ID NO: 1 or SEQ ID NO: 2 or fragments thereof. Naturally, as skilled artisans are aware, hybridization conditions may be adapted to compensate for differences in the sequence of the probes and the existence of different degrees of possible mismatches.
[0067] The genotype of the individual chicken is determined from the restriction pattern revealed by the labeled probe. What constitutes a pattern corresponding to a particular class I gene haplotype is ascertained in different ways depending on what is known about the genetics of the population being tested. If fully pedigreed families are tested, the transfer of restriction fragment patterns from sire and dam to progeny can be followed. Which individual restriction fragment patterns are inherited together in a single pattern representing the linked genes of each allele in a haplotype, can be deduced or assigned with a high degree of certainty if inheritance is followed over three generations.
[0068] The pattern of two alleles in the diploid individual constitutes the individual's genotype. Within a family, there is a maximum of four alleles or haplotypes to follow. These patterns can be followed and assigned without much effort by those of skill in the art. In subsequent samples from birds with the same genetic make-up, the restriction patterns associated with the different haplotypes present in each DNA sample then are easily recognized by the skilled worker. It is possible to discover pedigree errors in some samples. For example, there may be samples among progeny which have restriction fragments not present in either the sire or dam. These are most likely due to pedigree errors, mislabeled samples or, rarely, chance recombination.
[0069] In some instances, it is not possible to examine all of the alleles of interest in fully pedigreed families to assign the restriction fragment pattern passed from one generation to the next. Most commercial chickens are produced by the crossing of closed lines of limited genetic variability. In this case, exact correspondence is not known between sires and dams and their progeny. There are, however, a finite member of haplotypes segregating within a line, and the number tends to be fewer, particularly when the lines are somewhat inbred. In such a case, the patterns associated with each haplotype can be deduced as a matter of routine from the patterns presented by the population.
[0070] Because one has no means of ascertaining how many alleles may be present in a larger or outbred population, assigning haplotypes to various restriction patterns within such a population is more time consuming. Therefore, it is preferable to select individuals from the population for pedigree mating and analysis. When this is not possible, the DNA samples may be analyzed several times using different restriction enzymes to develop confidence that all alleles have been revealed. Once the individual restriction fragments are sorted into patterns that are inherited as a group, the pattern assignment can be tested in the next generations. If necessary, a breeder or other worker could do limited pedigreed hatching to verify the inheritance patterns deduced from population studies.
[0071] It was necessary to redefine a Y haplotype termed Y 1 based on an earlier restriction fragment with one probe into two different haplotypes Y 1.1 and Y1.2 when two different patterns were found among the Y 1 samples using the 163/164f probe of the invention. An example of this is provided in FIG. 7. Compare FIG. 7A, in which the restriction fragments were probed with the 163/164f probe of the invention, to FIG. 7B, in which a prior art crosshybridizing B system probe was used. The 163/164f probe revealed additional genotypic differences and allowed four Rfp-Y haplotypes to be distinguished. In FIG. 7A, the 163/164f probe detected at least one unique restriction fragment for each haplotype, allowing them to be distinguished. Note that band sharing is more frequent with the prior art B-LβII probe (FIG. 7B) and Y 1.1 and y 1.2 were not separated.
[0072] Because there are no standardized types in the Rfp-Y region, haplotyping in this region should be performed separately for each population. Therefore, each population of chickens will probably need to be analyzed using the strategies outlined above until more information about the different Y region haplotypes is obtained from different groups of chickens and more patterns have been assigned to haplotypes. The genotyping methods described herein may be used in connection with any species of domesticated fowl that possesses an Rfp-Y or B system. The methods herein disclosed are preferably used in genotyping programs for chickens, ring-necked pheasants or turkeys or any bird having an Rfp-Y system.
[0073] The 163/164 Y-specific probe can distinguish more polymorphic restriction fragments than prior art methods. Additionally, the 163/164f probe has the advantage of being specific for the Y system, avoiding the possibility of confusing crosshybridization with B system genes. The differences in Y haplotype distinguished with the 163/164f probe can predict differences in disease-resistance and mortality in a well recognized chicken disease model. This information, in addition to the demonstrated link between Rfp-Y haplotype and survivability of birds exposed to the commercially important Marek's disease and to other diseases of poultry, including avian Rous sarcoma virus, clearly demonstrates the usefulness of the 163/164f haplotyping probe in selection of breeding stocks for resistance to a variety of poultry diseases.
[0074] To utilize Rfp-Y haplotyping in a commercial breeding program, a database correlating Rfp-Y or B haplotypes to the desired disease resistance is created using studies correlating a bird's resistance to a disease with the haplotype revealed by the inventive probes. Breeders can then use this database in conjunction with information about Mhc haplotype in the available breeding lines to select parents for breeding. A database is created by challenging birds of known Mhc genotype with the disease of interest and correlating incidence, susceptibility or severity of disease with the Mhc genotype. The term “disease-resistance” or “disease-resistant” refers to birds which have a lower susceptibility to infection by the disease in question upon challenge, or which have a lower severity of the disease.
[0075] The following non-limiting examples are illustrative of the present invention. It is contemplated that modifications will readily occur to those skilled in the art within the spirit of the invention and the scope of the appended claims.
EXAMPLES
Example 1
Detection of Genetic Polymorphism in the Rfp-Y Region of Chickens of Known Haplotype
[0076] Genomic DNA from several chickens of known Rfp-Y and B genotype was purified according to methods known in the art. To isolate the genomic DNA, small blood samples (about 100 μl packed cells) were digested in Proteinase K/SDS overnight at 55° C., extracted three times with phenol/dichloromethane then extracted twice more with dichloromethane and dialyzed extensively against 10 mM Tris HCl, pH 8, with 1 mM EDTA (TE). These DNA samples previously had been tested with a prior art B (B-LβII) system probe which crossreacts with Y system genes. A 10 μg sample of purified chicken DNA was digested with a restriction endonuclease (TaqI) using the buffer and conditions suggested by the manufacturer. The digested DNA was then concentrated by ethanol precipitation and resuspended in TE. The DNA digest was applied to a 0.8% agarose gel (20×21 cm) and separated at 60V in 89 mM Tris-HCl, 89 mM boric acid, pH 8.0, containing 2.5 mM EDTA (TBE). The gel was then stained with ethidium bromide and photographed under UV light. The gel was then treated for 10 minutes in 0.25 N HCl and the DNA transferred in 0.4 N NaOH to a hybridization membrane (Gene Screen™; NEN Life Science Products, Boston). After washing with distilled water and citrate buffer (0.3 M NaCl, 0.03 M sodium citrate, pH 7.0), the DNA was crosslinked to the membrane by short (2 minute) exposure to UV light in a UV-light DNA crosslinker (Stratalinker™; Stratagene, La Jolla, Calif.).
[0077] Labeled ( 32 P) 163/164f probe (SEQ ID No: 1) was hybridized to the DNA on the membrane filters under stringent conditions (65° C. overnight in 5× SSPE, 5× Denhardt's solution, 1% SDS with 100 μg/ml denatured salmon sperm DNA. The 32 P-labeled probe was present at 1-2×10 6 cpm/ml. The hybridization was performed in Robbins™ hybridization tubes, containing 3 or 10 ml of the above hybridization solution in a hybridization incubator (Robbins Model 310, Sunnyvale, Calif.). The membranes then were treated with a stringent temperature wash at 65° C. in 75 mM NaCl, 7.5 mM sodium citrate, pH 7. Images of the hybridized membranes were then developed, revealing different multiple bands of genomic chicken DNA for each individual chicken tested. The genetic fingerprint of each individual chicken shown identifies the haplotype of that individual in the Rfp-Y region. See FIG. 7.
Example 2
[0078] Determination of the B Region Genotype of the Progeny of Chickens of Known Haplotype
[0079] The method of Example 1 was repeated on two serologically typed families having the same sire but two different dams, substituting the 178/179f probe for the 163/164f probe. See FIG. 6C. In this example, however, PstI was the restriction enzyme, and the buffer and conditions suggested by the manufacturer were used for digestion. The samples analyzed here were assigned to B haplotypes based on the names from existing serological reagents. In FIG. 6C, there is a clear correspondence between the BR9 haplotype and one restriction fragment and the B11 haplotype and a doublet of restriction fragments, one larger and one smaller than the band corresponding to BR9. It is therefore possible to easily determine which B types were inherited by each of the progeny. The genotype is indicated along the top of FIG. 6C.
Example 3
[0080] Determination of the Rfp-Y Haplotype of Individual Chickens
[0081] The methods of Example 1 were repeated using BglI-digested DNA samples from a cohort of chickens derived from a previously typed parental generation, for which there is some pedigree data. The exact sire and dam for each individual was not known, however. See FIG. 8. The leftmost four lanes indicate the deduced patterns for the indicated homozygotic conditions. These four patterns are seen to be combined variously in patterns interpreted as those of heterozygous individuals. The Y genotypes deduced from the multiple patterns present are listed across the top right portion of FIG. 8A. Because there are only four patterns segregating in this population, the various heterozygote combinations were easily determined. The rare pattern, Y 3 /Y 6 +, was detected in this population (see fourth lane). Only three Rfp-Y haplotypes could be deduced when restriction fragment patterns in the same samples were probed with a prior art B-Lβ11 probe that hybridizes to both B and Rfp-Y restriction fragments. Compare FIG. 8A to FIG. 8B.
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Disease resistance in domesticated fowl, and in particular, chickens, has been associated with certain alleles of the Rfp-Y and B systems of major histocompatibility genes in the birds. This invention provides a method of genotyping chickens which is useful for different breeds of chickens raised for meat and eggs. Methods for selecting disease-resistant chickens and for breeding disease-resistant chickens are also provided. The invention provides oligonucleotide probes for use in the methods. The haplotyping method can be used to select for breeding chickens having a reduced incidence and/or severity of disease, for example, Marek's disease and greater vigor and fecundity.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application is a continuation of U.S. patent application Ser. No. 13/096,901 titled “Self Contained Fire Extinguisher System Including A Linear Temperature Sensor” filed on Apr. 28, 2011, now allowed, the entire content of which is herein expressly incorporated by reference.
FIELD OF THE INVENTION
The present disclosure generally relates to self contained fire extinguisher systems. More particularly, the present disclosure relates to self contained fire extinguisher systems that do not need external power in order to sense or initiate a release of a fire suppression medium.
Examples of applications for embodiments according to the present disclosure include kitchens, terrestrial vehicles, marine vessels and aircraft. These applications may be civilian, commercial or military.
DESCRIPTION OF CONVENTIONAL TECHNOLOGY
Certain conventional fire extinguishing systems typically include a manually operated, pressurized source of a fire suppression medium. Other conventional fire extinguishing systems may include a sensor that requires external power to send an initiation signal to a source of a fire suppression medium, e.g., a pressurized cylinder, which is remotely located from the sensor. These sensors may detect heat and/or smoke by electrical means. If the electrical power is interrupted or disengaged by collateral damage or due to the fire, these conventional fire extinguishing systems may be rendered inoperative.
Military vehicles are examples of applications that are sensitive to loss-of-power to an onboard fire extinguishing system because the crew is frequently in close confinement with limited egress opportunity and no access to back-up fire suppression mediums. Moreover, a fire aboard a military vehicle may be caused by a landmine, projectile or other violent event that may result in immediate, collateral damage to the power network for the vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a cross-section view of an embodiment of a linear temperature sensor cord according to the present invention.
FIG. 1B illustrates a method for manufacturing the linear temperature sensor cord shown in FIG. 1A .
FIGS. 1C-1E are perspective and cross-section views of variations of the linear temperature sensor cord shown in FIG. 1A .
FIGS. 2A and 2B are perspective views of embodiments of protection for the linear temperature sensor cord shown in FIG. 1A .
FIGS. 3A-3C are perspective views of attaching devices for the linear temperature sensor cord shown in FIG. 1A .
FIG. 4A is a cross-section view of an end for the linear temperature sensor cord shown in FIG. 1A .
FIG. 4B illustrates a method of assembling the end shown in FIG. 4A .
FIG. 4C is a cross-section view of a network juncture for coupling the ends of two of the temperature sensor cords shown in FIG. 4A .
FIG. 4D is a cross-section view of a network manifold for coupling the ends of four of the temperature sensor cords shown in FIG. 4A .
FIGS. 5A and 5B are cross-section views of boost initiators coupled to ends of the linear temperature sensor cord shown in FIG. 1A .
FIGS. 5C-5E are perspective views of initiators, actuators and valves including one of the boost initiators shown in FIGS. 5A or 5B .
FIGS. 6A-6C are schematic views showing embodiments including multiple linear temperature sensor cords coupled to multiple fire suppression medium sources.
FIG. 7A is a schematic view showing an embodiment including multiple linear temperature sensor cords coupled to multiple fire suppression medium sources and manual initiators.
FIGS. 7B and 7C are perspective views of manual initiators shown in FIG. 7A .
DETAILED DESCRIPTION
The following describes embodiments of self contained fire extinguisher systems and methods of making and using self contained fire extinguisher systems in accordance with the present disclosure. Embodiments in accordance with the present disclosure are set forth in the following text to provide a thorough understanding and enabling description of a number of particular embodiments. Numerous specific details of various embodiments are described below with reference to self contained fire extinguisher systems on military vehicles, but embodiments can be used with other military, commercial or civilian vehicles, including terrestrial vehicles, marine vessels and aircraft. Embodiments of self contained fire extinguisher systems according to the present disclosure may also be used in static structures, e.g., kitchens. In some instances, well-known structures or operations are not shown, or are not described in detail to avoid obscuring aspects of the inventive subject matter associated with the accompanying disclosure. A person skilled in the art will understand, however, that the invention may have additional embodiments, or that the invention may be practiced without one or more of the specific details of the embodiments as shown and described.
FIG. 1A shows an embodiment of a linear temperature sensor cord 100 according to the present invention. The cord preferably includes a core 101 and a casing 102 . The core 101 is preferably a pyrotechnic blend of fuel and oxidizer powders with additives that result in a low auto-ignition temperature, for example, in a range of approximately 225 degrees Fahrenheit to approximately 800 degrees Fahrenheit. Generally, the range of auto-ignition temperatures is approximately 275 degrees Fahrenheit to approximately 680 degrees Fahrenheit, and preferably approximately 340 degrees Fahrenheit to approximately 400 degrees Fahrenheit. Test results have demonstrated that, in a typical diesel fuel fire and with the cord 100 spaced nominally 18 inches from the fuel, combustion of the cord 100 initiates in less than approximately 60 seconds. In addition to auto-igniting, the core 101 burns rapidly to provide a short response time, e.g., combustion propagates rapidly along the length of the cord 100 . Other embodiments according to the present disclosure may have cores 101 without additives.
Embodiments of the cord 100 according to the present disclosure may have other constructions. For example, the casing 102 may include the fuel or the oxidizer and the core 101 may include the oxidizer or the fuel, respectively. Such a cord 100 may accordingly be consumed during combustion propagation. Other embodiments may include a pyrotechnic fluid core 101 , e.g., a liquid or gas, that may be disposed inside or applied, e.g., sprayed, dipped, etc., onto a casing 102 . Other embodiments according to the present disclosure may have other cores, e.g., a wick treated with a pyrotechnic fluid.
FIG. 1B illustrates a method for manufacturing the linear temperature sensor cord 100 . The casing 102 preferably includes a metal tube into which the pyrotechnic blend for the core 101 is loaded. The metal tubes may then pass thru dies, rollers, or other swaging devices to elongate the tube and reduce the diameter of the cord 100 . The tube material and properties may be selected for optimum thermal conductivity and tensile strength. Preferably, the diameter of the pyrotechnic core is selected for ensuring that combustion of the pyrotechnic core 101 propagates around bends formed in the cord 100 . The wall thickness may be predetermined according to the swaging procedure. The walls of the casing 102 are preferably concentric with the longitudinal axis of the cord 100 and preferably have a consistent wall thickness. Preferably, the linear temperature sensor cord 100 can be easily bent by hand or by conventional tube bending tools and techniques to conform to a selected contour or path without crimping the cord 100 .
FIGS. 1C-1E show arrangements of the linear temperature sensor cord 100 including features for adjusting sensitivity of the cord 100 to ambient temperature. FIG. 1C shows the cord 100 including a flattened portion 110 , FIG. 1D shows the cord 100 including a portion 120 having a cross-shaped cross-section, and FIG. 1E shows the cord 100 including a coiled portion 130 . The flattened portion 110 , the cross-shaped portion 120 , the coiled portion 130 , and other arrangements may provide the cord 100 with increased temperature sensitivity by increasing the surface area and/or thinning the wall of the casing 102 .
Other embodiments according to the present disclosure may have casings 102 that include materials other than metal, e.g., natural fibers, polymers or other materials through which an elevated ambient temperature may be conveyed to auto-ignite the pyrotechnic core 101 . The casing 102 may also include a hybrid composition, e.g., metal fibers woven into a tubular cotton sleeve. Other manufacturing methods, e.g., extruding or weaving, may also be used for manufacturing the cord 100 .
FIGS. 2A and 2B show two embodiments according to the present disclosure for partially enclosing and protecting the linear temperature sensor cord 100 . In particular, it may be desirable to at least partially enclose the cord 100 to protect it from impact, abrasion or other damage in exposed areas and/or to shield the cord 100 in areas that do not require temperature sensing. The cord 100 can be inserted in a solid or perforated metal tube 202 or a non-metallic sheath 203 for protection. These protective coverings or shields may be implemented at intervals along the longitudinal axis of the cord 100 , thus leaving uncovered or exposed portions along the longitudinal axis of the cord 100 . Portions of the cord 100 that are covered with the sheath 203 may have reduced temperature sensitivity relative to the uncovered portions. It would therefore be preferable for sheaths 203 to be located along non-sensing lengths of the cord 100 for providing, for example, added impact or abrasion protection. The uncovered portions are preferably positioned in locations where it is desirable for the cord 100 to sense elevated ambient temperatures due to a fire. The tube 202 may provide impact protection substantially without adversely affecting the sensitivity of the cord 100 . For example, the thermal conductivity and/or perforations of the tube 202 may minimize any impediment that the tube 202 may cause to the cord 100 for sensing elevated temperatures due to a fire. Accordingly, the tube 202 and/or the sheath 203 may ruggedize or provide additional protection to portions of the cord 100 without compromising the sensitivity of other portions of the cord 100 .
FIGS. 3A-3C show attaching devices for supporting the linear temperature sensor cord 100 . FIG. 3A shows a resilient metal clip support device 301 , FIG. 3B shows an elastically deformable elastomer support device 302 , and FIG. 3C shows a preformed or plastically deformable wire form support device 303 . The support devices 301 / 302 / 303 may support the cord relative to structures (not shown) in the temperature sensing areas. Variants of these support devices may also be used to support covered portions of the cord 100 , e.g., portions of the cord 100 covered by the tube 202 or the sheath 203 .
FIG. 4A shows a cup 401 enclosing an end of the linear temperature sensor cord 100 , and FIG. 4B illustrates a method of assembling the cup 401 onto the cord 100 . Preferably, the cup 401 includes a thin-walled metallic cup that is partially filled with additional pyrotechnic material 402 . The cup 401 preferably slides onto and seals the end of the cord 100 . The additional pyrotechnic material 402 may provide a booster to propagate the initiation signal across junctions or manifolds for networking plural cords 100 .
The material for the cup 401 may the same or different from that of the casing 102 , and the additional pyrotechnic material 402 may be the same or different from that of the core 101 . Friction, adhesive, mechanical devices, or other coupling techniques may be used to temporarily or substantially permanently secure the cup 401 to the casing 102 .
FIG. 4C shows a network juncture 403 a for coupling together ends of two temperature sensor cords 100 . FIG. 4D is a cross-section view of a network manifold 403 b for coupling together ends of four temperature sensor cords 100 . Embodiments according to the present disclosure may include network couplings for three, five or more cords 100 , and may include any geometry that is suitable for propagating combustion across two or more ends.
FIGS. 5A and 5B show two embodiments of a boost initiator 500 that may be coupled at an output end of the linear sensor temperature cord 100 . The boost initiator boosts the combustion output of the cord 100 to (1) ignite a propellant fire suppression medium; (2) provide pressure to open a valve; or (3) provide pressure to puncture a sealing disc. FIG. 5A shows a pyrotechnic charge 501 that is initiated by the cord 100 . The size and material for the pyrotechnic charge 501 may be tailored to produce a selected quantity of pressure and/or heat, which may directly ignite a propellant type fire suppression medium, operate a valve, or rupture a sealing disc. The material for the pyrotechnic charge 501 may be the same or different from that of the core 101 and/or the additional pyrotechnic material 402 .
Referring to the embodiment of the boost initiator 500 shown in FIG. 5B , an integral metallic bulkhead 502 may be placed between two thermally sensitive charges, e.g., a donor charge 503 and a receptor charge 504 . The temperature of each charge is sufficient to transfer ignition across the bulkhead 502 without compromising the structural integrity of the bulkhead 502 . The size and material for the receptor charge 504 may be tailored to produce a selected quantity of pressure and/or heat 505 , which may directly ignite a propellant type fire suppression medium or operate a valve or rupture a sealing disc while maintaining a pressure seal across the bulkhead 502 . The material(s) for the donor and receptor charges 503 / 504 may be the same or different from that of the core 101 and/or the additional pyrotechnic material 402 .
Embodiments according to the present disclosure may include several options for a fire suppression medium and its source. Fire suppression mediums may include, e.g., dry chemicals, liquids or inert gases. The sources for dry chemical and liquid fire suppression mediums are typically pressure vessels. Discharging these fire suppression mediums from pressure vessels typically includes opening a valve or rupturing a sealing disc. Inert gas fire suppression mediums are typically combustion products of a propellant that is not stored under pressure. Pressure from an inert gas fire suppression medium may be generated when the propellant is ignited and the resulting combustion produces a pressurized inert gas as the output.
FIGS. 5C-5E show embodiments of initiators, actuators and valves including one of the boost initiators 500 . FIG. 5C shows an inert gas generator propellant 510 that is initiated by the pyrotechnic charge 501 . Accordingly, an inert gas fire suppression medium is discharged via an outlet 512 , e.g., a nozzle, in response to the propellant 510 being ignited or initiated by the pyrotechnic charge 501 , which is preferably initiated by the linear sensor temperature cord 100 in response to sensing an elevated temperature that causes auto-ignition of the core 101 .
FIG. 5D shows an actuator for discharging a pressurized fire suppression medium 520 , e.g., a liquid or dry chemical fire suppression medium. The fire suppression medium 520 is discharged in response to the output of a boost initiator 500 displacing a piston 522 , which causes a sealing disc 524 to rupture thus allowing the pressurized fire suppression medium 520 to discharge through an outlet 526 . The boost initiator 500 is initiated by the linear sensor temperature cord 100 in response to sensing an elevated temperature that causes auto-ignition of the core 101 .
FIG. 5E shows a valve for discharging a pressurized fire suppression medium 530 . The fire suppression medium 530 is discharged in response to the output of a boost initiator 500 displacing a piston 532 relative to a valve body 534 . Preferably, this causes a shear nipple 536 to be lopped off thus allowing the pressurized fire suppression medium 530 to be discharged through an outlet 538 . The boost initiator 500 is initiated by the linear sensor temperature cord 100 in response to sensing an elevated temperature that causes auto-ignition of the core 101 .
Embodiments according to the present disclosure may include other configurations and combinations of fire suppression medium sources, discharge controllers and boost initiators. For example, certain embodiments according to the present disclosure may eliminate the boost initiator if the output pressure and/or heat from the linear sensor temperature cord is sufficient to actuate the discharge controller. In lieu of an electrically operated system, auto-ignition of the core of the linear sensor temperature cord in response to sensing an elevated temperature causes the fire suppression medium to be discharged. Also, a network of the linear sensor temperature cords can be provided with different end configurations depending on the type of fire suppression medium and its source.
FIGS. 6A-6C schematically show examples of systems that include one or more of the linear temperature sensor cords 100 to initiate a propellant, puncture a disk, or activate a valve on one or more sources of the fire suppression mediums 510 / 520 / 530 . Preferably, the linear temperature sensor cord(s) connect to one or more inert gas generators. The cord(s) 100 can interface with a boost initiator 500 or directly with an igniter of the inert gas generator for initiating the propellant 510 . A solid inert gas generator propellant 510 may be preferable because it does not need to be stored in a pressurized cylinder and there is no residual material to remove or clean up after an inert gas discharge.
FIG. 6A shows six sources of one or more of the fire suppression mediums 510 / 520 / 530 . A plurality of the linear temperature sensor cords 100 (eight are shown in FIG. 6A ) are coupled to sources or one another by network manifolds 403 b (three are shown in FIG. 6A ). In one embodiment according to the present disclosure, four of the six sources may be disposed in corresponding wheel wells of a vehicle and the two additional sources may be disposed proximate to the vehicle's running gear, e.g., in the engine compartment, battery compartment, etc. Core combustion is initiated when the ambient temperature exceeds the auto-ignition temperature of at least one of the cords. The networked cords and sources are accordingly initiated and the fire suppression medium(s) are discharged.
FIG. 6B shows one embodiment according to the present disclosure for providing a fire suppression system in a crew compartment of a vehicle. At least one linear temperature sensor cord 100 (seven are shown in FIG. 6B ) is coupled to at least one source (six are shown in FIG. 6B ) of a fire suppression medium 510 / 520 / 530 . The sources are preferably disposed inside a generally enclosed crew compartment and linked by networked cords for initiating the sources if the internal temperature exceeds the auto-ignition temperature. Additional networked cords (two are shown in FIG. 6B ) may be used to also initiate the sources if a temperature external to the crew compartment exceeds the auto-ignition temperature.
Certain embodiments according to the present disclosure may include implementing both the fire suppression system for the physical components ( FIG. 6A ) and the fire suppression system for the crew compartment ( FIG. 6B ) onboard a single vehicle as independent systems. Moreover, independent systems for additional compartments, e.g., cargo holds, fuel tanks, ammunition lockers, etc., may also be included on a single vehicle. An integrated fire suppression system for a single vehicle may include a network of linear temperature sensor cords that couple together all of the sources onboard the vehicle.
FIG. 6C shows an embodiment according to the present disclosure including a single length of the linear temperature sensor cord 100 and a single source of a fire suppression medium 510 / 520 / 530 . The single length may include a plurality of individual cords coupled in series by junctions (not shown). The linear temperature sensor cord may extend to several locations in a single compartment and/or may include portions extending into different spaces of a vehicle. Thermal insulators 600 disposed around portions of the cord 100 may provide impact protection and/or reduce sensitivity to elevated temperatures that are routinely anticipated, e.g., proximate an engine exhaust, and therefore do not represent a fire. Preferably, the single source may be dedicated to providing a fire suppression system at a particular location, e.g., a vehicle's driver seat, in response to threats of fire from multiple locations/spaces around the vehicle. One or more of these individual fire suppression systems may be used on a single vehicle, with or without a networked fire suppression system also being onboard the vehicle.
FIG. 7A schematically shows an embodiment according to the present disclosure of a fire suppression system 700 for a vehicle including a manual initiator 701 that can activate initiation the system 700 at any time or temperature. The system 700 preferably includes a plurality of networked linear temperature sensor cords 100 (only one is indicated in FIG. 7A ), a plurality of sources of a fire suppression medium 510 / 520 / 530 (six sources including gas generator propellants 510 a - 510 f are shown in FIG. 7A ), and a plurality of manual initiators 701 (four manual initiators 701 a - 701 d are shown in FIG. 7A ).
The sources of the fire suppression medium 510 are preferably distributed for discharging in the engine compartment 510 a / 510 b and each of the wheel wells 510 c - 510 f. Alternate or additional sources may also be positioned in other locations on the vehicle.
The manual initiator 701 a is preferably located in the crew compartment of the vehicle, e.g., within reach of the driver. Alternate or additional manual initiators may be positioned around the exterior of the vehicle. For example, the manual initiator 701 b may be positioned on the vehicle exterior, e.g., proximate an entrance to the crew compartment at the back of the vehicle, and/or manual initiators 701 c / 701 d may be positioned on the either of the vehicle's exterior sides.
FIGS. 7B and 7C are perspective views of examples of the manual initiators 701 shown in FIG. 7A . FIG. 7B shows an embodiment according to the present disclosure that includes a pull handle 702 for initiating the cord 100 coupled to the manual initiator 701 and FIG. 7C shows an embodiment according to the present disclosure that includes a rotary handle 703 for initiating the cord 100 coupled to the manual initiator 701 . In the event of a fire that does not reach the auto-ignition temperature, the manual initiators 701 can be manually activated. The manual initiators 701 are preferably positioned in non-hazardous areas and coupled to the sources of fire suppression medium 510 / 520 / 530 with the linear temperature sensor cords 100 . An example of a manual initiator is Part Number 813633-3 manufactured by Pacific Scientific Energetic Materials Co. (Hollister, Calif.).
A method for suppressing a fire will now be described. Embodiments according to the present disclosure preferably include a linear temperature sensor cord 100 that, when exposed to a fire having a temperature that exceeds the auto-ignition temperature of the cord 100 , initiates combustion of the cord's core 101 . This core combustion propagates along the cord 100 to a source of a fire suppression medium 510 / 520 / 530 that is preferably positioned in a location to discharge the fire suppression medium 510 / 520 / 530 to suppress the fire. Core combustion may propagate in a network of the cords 100 to initiate or actuate one or more suppression medium sources. Likewise, individual suppression medium sources may be activated or initiated in response to core combustion from one or more of the cords 100 . Core combustion may provide adequate pressure and/or heat to activate or initiate the fire suppression medium source, or a boost initiator 500 may couple the cord 100 to the source for increasing the pressure and/or heat from the cord 100 , and thereby provide sufficient pressure and/or heat to activate or initiate the source. The fire suppression medium sources preferably include a propellant 510 that is initiated to produce a fire suppression medium, a pressurized fire suppression medium 520 that is released by rupturing a sealing disk, or a pressurized fire suppression medium 530 that is released by opening a valve. Embodiments according to the present disclosure discharging the fire suppression medium 510 / 520 / 530 without an electrical signal. Accordingly, a fire or damage that disrupts electric power or circuits will not in turn adversely affect the fire suppression performance of embodiments according to the present disclosure.
A method of providing a fire suppression system onboard a vehicle will now be described. Embodiments according to the present disclosure preferably include a linear temperature sensor cord 100 that is routed into or through compartments or other locations on the vehicle such as engine compartments, crew compartments, wheel wells, fuel tanks, cargo holds, etc. The cord 100 may include an end positioned in a compartment or may include a loop or segment disposed in a compartment. Ends of the cord 100 are preferably enclosed by a cup 401 , coupled to a boost initiator 500 at a source of a fire suppression medium 510 / 520 / 530 , coupled directly to the source of the fire suppression medium 510 / 520 / 530 , coupled to one or more manual initiators 701 , or networked with one or more other cords 100 via a juncture 403 a or a manifold 403 b . Portions of the cord(s) 100 may be shielded from impact or abrasion with or without an appreciable effect on the temperature sensitivity of the cord 100 . For example, one or more portions of a cord 100 may be cinctured by a tube 202 or a sheath 203 with minimal impact on the ability of the cord 100 , and/or an insulator 600 may make one or more portions of the cord 100 less sensitive to the ambient temperature. Cords 100 may be bent or otherwise formed into shapes that follow a selected route and may be supported with respect to vehicle along that route by resilient clips, wires, etc. The route that the cord(s) follow may also extend on external surfaces of the vehicle.
Embodiments according to the present disclosure may also be applicable to other environments such as kitchens, warehouses, or any structure in which it is preferable to provide fire suppression capabilities during electrical power outages. Embodiments according to the present disclosure may also be applicable anywhere electricity for a fire suppression system is not available.
Embodiments according to the present disclosure may provide an elongated fire sensor rather than a conventional sensor that is located at a specific position and coupled by wires to a discharge controller. In contrast to these conventional sensors, the entire length of the linear temperature sensor cord 100 may provide fire sensing capabilities in addition to transmitting a signal to discharge a fire suppression medium.
Embodiments according to the present disclosure may also be used to break an electrical circuit. For example, a fire in a particular space may be sensed by an embodiment of the cord according to the present disclosure. The cord may be disposed throughout the space rather than using a conventional sensor(s) disposed at discrete locations. In response to auto-igniting the cord, an embodiment of the boost initiator according to the present disclosure may cut electrical power to the space.
From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications can be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited by the specific embodiments.
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A self contained fire extinguisher system that does not need external power in order to sense or initiate a release of a fire suppression medium, includes components configured to utilize a linear sensor network that can be connected to at least one and/or different sources of fire suppression mediums. A linear temperature sensing cord can be routed over a large area not practical with individual sensors. The cord can also actuate several and different sources of fire suppression mediums to maximize the suppression of a fire.
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BACKGROUND OF THE INVENTION
This invention relates to an improvement in the process for isolating chloroprene polymers from their alkaline latices. Chloroprene polymers within the scope of this invention include, in addition to homopolymers of chloroprene, also copolymers of chloroprene with up to equal weight of copolymerizable organic monomers.
Polymerization of chloroprene with or without additional monomers usually is carried out in a soap-stabilized, alkaline, aqueous emulsion. Soaps normally used in such polymerizations are the sodium or potassium salts of rosin or modified rosin. The preferred process for isolating the polymer from the latex involves continuous formation of a polymer film by coagulation on a freeze drum, followed by washing of the film and drying, as described by M. A. Youker in Chemical Engineering Progress, Vol. 43, No. 8, pp. 391-398 (1947). The process is also described in U.S. Pat. Nos. 2,187,146; 3,310,544; and 3,311,601. For most efficient coagulation at the freeze drum, the latex is made slightly acidic prior to the freeze-drum step. To prevent premature coagulation of the latex during the acidification, small amounts of acid-stable surfactants should be present in the latex. These either are present in the emulsion during the polymerization or are added afterwards to the latex.
The acidification is carried out with weak acids such as acetic acid. Strong mineral acids are avoided because even at high dilution they tend to coagulate the latex. Premature coagulation of the latex causes the formation of large irregular masses of polymer which eventually make further operation of the process difficult or impossible. The pH of the latex at the beginning of the freeze-drum isolation step is about 5.0-6.5.
Acidification of the alkaline latex with acetic acid gives sodium acetate, which is occluded in part in the coagulated polymer film. A certain amount of this sodium acetate is desirable because it improves the storage and aging stability of the polymer. However, too much sodium acetate is undesirable because it reduces the curability of th polymer. The amount of sodium acetate remaining in the polymer is ordinarily referred to in the industry as the polymer's alkaline reserve. This is determined by titrating a tetrahydrofuran solution of the polymer with aqueous hydrochloric acid to a neutral red end point (pH 6.2-6.4) using methylene blue as indicator. The measured value is usually between 0.6 and 2.2 milliequivalents of HCl per 100 g. of polymer.
Because of the criticality of the alkaline reserve, the chloroprene polymer film which leaves the freeze drum is subjected to a washing step. The efficiency of this step is dependent on the film thickness and tends to decrease as the film thickness increases. This problem becomes even more complicated when low alkaline reserve is desired. It can be readily seen that the entire process for the isolation of the chloroprene polymer from its latex can be limited by the ability of the washing system to remove sodium acetate from the polymer film to the desired level in the given time. If this step is slow, the plant output will be limited; but if the efficiency of the washing step could be improved or another method of obtaining the desired alkaline reserve were found, the production rate could be increased.
SUMMARY OF THE INVENTION
According to this invention, it has now been discovered that a proper alkaline reserve can be obtained if the pH of the latex is brought to a pH of about 5.0-6.5 by adding to the latex a combination of a suitable strong acid and a suitable weak acid prior to freeze-drum polymer isolation. Suitable strong acids are oxalic acid and sulfonic acids of the formula RSO 3 H where R is (a) a C 4 -C 11 alkyl, or (b) an aryl, alkaryl, or aralkyl group in which the sum of the number of any alkyl carbons plus one-half the number of aryl carbons totals 3-11. Suitable weak acids are C 1 -C 6 carboxylic acids having a first ionization constant whose negative logarithm, pKa, at 25°C., is within the range of about 3.5-5.0. The proportion of the strong acid in the acid mixture is 10-80 mole percent, preferably 15-60 mole percent.
DETAILED DESCRIPTION OF THE INVENTION
The chloroprene polymers which can be isolated from their latices according to the process of this invention may be copolymers of chloroprene with olefinic or vinyl comonomers. Suitable comonomers include, for example, styrene, the vinyltoluenes and vinylnaphthalenes, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2,3-dichloro-1,3-butadiene, methyl vinyl ether, vinyl acetate, methyl vinyl ketone, acrylic and methacrylic acids, ethyl acrylate, methylmethacrylate, methacrylamide, and acrylonitrile.
Representative suitable sulfonic acids include butanesulfonic acid, hexanesulfonic acid, decanesulfonic acid, benzenesulfonic acid, naphthalenesulfonic acid, toluenesulfonic acid, xylenesulfonic acid, cumenesulfonic acid, butylnaphthalenesulfonic acid, diisopropylnaphthalenesulfonic acid, and benzylsulfonic acid. Toluenesulfonic and xylenesulfonic acids are preferred.
If sulfonic acids are used in which the number of carbon atoms is less than the minimum number specified above, premature coagulation of the latex occurs in the acidification step. Above the upper limit of the indicated range of the number of carbon atoms, the chloroprene polymer latex does not coagulate efficiently at the freeze drum.
When oxalic acid is used as the strong acid, it is recommended that demineralized water be used in the process because of the risk of formation of insoluble salts, such as calcium or magnesium oxalates, which reduce the operable life of the cloth surface of squeeze rolls in one of the subsequent steps.
Suitable weak acids include, for example, acetic acid, propionic acid, formic acid, benzoic acid, and lactic acid. Acetic acid is preferred.
The ratio of strong acid to weak acid is critical. If not enough of the strong acid is used, an insufficient improvement over past methods is obtained. If too much strong acid is used, the isolated polymer does not have sufficient alkaline reserve for good storage stability.
If the strong acid were used alone, for example, the resulting polymer would have little or no alkaline reserve. Such a product tends to scorch (vulcanize prematurely) and has very limited storage stability. The weak acid in the mixture provides alkaline reserve of the product, this alkaline reserve being proportional to the amount of weak acid in the acidifying mixture. By selecting the proper molar ratio of strong or weak acid, one can maintain the alkaline reserve of the polymer product at the desired level, for example, 0.6-2.2 milliequivalents of HCl per 100 g. of polymer. In this manner, the polymer washing step may be omitted or at least considerably simplified.
Since all industrial processes comprise a polymer washing step, and all plants have the necessary equipment, it is expected that the washing step will not be eliminated. However, because of the flexibility which this invention provides of actually tailoring the alkaline reserve according to specific needs by the proper choice and proportions of strong and weak acids in the acidification step, the washing conditions can be maintained constant. In present industrial processes, it is necessary to wash thinner films or to wash at a slower rate if lower alkaline reserve is required, and some low alkaline reserve levels cannot even be reached. The present process does not suffer from these limitations.
The mixture of the weak acid and the strong acid is preferably prepared in advance before it is added to the latex. To avoid local coagulation, it is preferred to use aqueous solutions of the acids, the final mixture being about 2-5N. More dilute solutions can be used but would cause undesirable latex dilution. More concentrated solutions should be used cautiously to avoid partial coagulation of the latex. It also is practical to have present in the acid solution about 1-4%, based on the weight of the solution, of an acid-stable surfactant. Typical acid-stable surfactants include sodium or potassium salts of a formaldehyd-naphthalenesulfonic acid condensate or of dodecylbenzenesulfonic acid. The acid-stable surfactant may also be added in its free acid, rather than salt, form. The presence of surfactants further reduces the risk of local coagulation.
This invention is now illustrated by the following examples of certain representative embodiments thereof, wherein all parts, proportions, and percentages are by weight, unless otherwise indicated. In all examples, the latex was acidified to a pH 5.5.
PREPARATION OF NOEPRENE LATEXES
Latex A is prepared as follows:
A polymer dispersion is made by emulsifying 100 parts by weight of chloroprene, containing in solution 0.6 part of sulfur and 4.0 parts of wood rosin, in a water solution containing 122.5 parts of water, 0.75 part of sodium hydroxide and 0.5 part of the sodium salts of the condensation product of naphthalenesulfonic acids with formaldehyde, serving as the acid-stable dispersing agent. The sodium hydroxide in one phase reacts with the rosin in the other, forming sodium salts of the rosin which act as the main emulsifying agent. The emulsified chloroprene is then polymerized at 40°C. by adding as catalyst, a solution of 0.50 part of potassium persulfate and 0.025 part of the sodium salt of anthraquinone beta-sulfonic acid in 9.47 parts of water. Part of this is added at the start and part during the course of the polymerization, to maintain a fairly uniform rate of polymerization. The course of the polymerization is followed by determining the specific gravity of the dispersion. When this reaches 1.072 at 40°C., corresponding to 90% conversion to polymer, the reaction is "short stopped" by adding 0.45 part of tetraethyl thiuram disulfide dissolved in 2.95 parts of toluene dispersed in 2.22 parts of water by means of 0.30 part of the sodium salts of long chain sodium alkyl sulfates and 0.06 part of the sodium salts of the condensation product of naphthalenesulfonic acids with formaldehyde.
To this polymer dispersion is added 0.19 part of the sodium dibutyl dithiocarbamate in 0.61 part of water. After cooling to 25°C. and aging for 4 hours at that temperature, the dispersion is stripped with steam at reduced pressure in a turbannular flow tube, as described in U.S. Pat. No. 2,467,679, to remove unpolymerized chloroprene and other volatile components.
Latex B is prepared in a manner similar to that of Latex A by polymerizing chloroprene containing 0.15 weight percent of dissolved dodecyl mercaptan at 10°-20°C. in an aqueous emulsion stabilized by the sodium soap derived from 3.5 parts of disproportionated wood rosin per 100 parts of chloroprene.
EXAMPLE 1
(Control, outside the scope of this invention)
An aqueous solution containing 30% of acetic acid and 2% of the sodium salts of the condensation products of naphthalenesulfonic acid and formaldehyde is slowly added to 1450 g. of Latex A. The acid solution is added at a rate of approximately 50 g./min., while the latex is rapidly stirred, until the pH of the latex declines to 5.5.
The acidified latex is then coagulated by freezing in thin layers as described in Example 4 of U.S. Pat. No. 2,187,146, using a freeze drum measuring 13 inches in diameter, and the resulting sheets of polymer and washed with water and dried. The dried polymer has an alkaline reserve of 1.32 meq. of HCl per 100 g. of polymer.
EXAMPLE 2
Acidification of Latex A is carried out with an aqueous solution formed by mixing together 52.5 g. of glacial acetic acid, 23.6 g. of oxalic acid dihydrate, 305 ml. of water, and 7.6 g. of the sodium salts of the condensation products of naphthalenesulfonic acid and formaldehyde. The thickness of the polymer sheets and the conditions of washing are identical to those of Example 1. The dried polymer has an alkaline reserve of 1.11 meq. of HCl per 100 g. of polymer.
EXAMPLE 3
Latex A is acidified with an aqueous solution formed by mixing together 36.5 g. glacial acetic acid, 32.9 g. oxalic acid dihydrate, 425 ml. water, and 10.0 g. of the sodium salts of the condensation products of naphthalenesulfonic acid and formaldehyde. The product, which is washed and dried as in Example 2, has an alkaline reserve of 0.7 meq. of HCl per 100 g. of polymer.
Comparison of Examples 2 and 3 with Example 1 shows that by varying the ratio of oxalic acid to acetic acid in the acidifying solution the alkaline reserve of the product can be varied without altering the conditions of the polymer washing step. This result, furthermore, is achieved without formation of coagulum during addition of the acid solution to the latex.
EXAMPLE 4
(control, outside the scope of this invention)
Example 1 is repeated using Latex B in place of Latex A. The alkaline reserve of the dried polymer is 2.01 meq. of HCl per 100 g. of polymer.
EXAMPLE 5
Latex B is acidified with a solution formed by dissolving in 375 g. of water 56 g. glacial acetic acid, 50 g. of a mixture of acids consisting of 60 parts of toluenesulfonic acid, and 40 parts of xylenesulfonic acid, and 12.5 g. dodecylbenzenesulfonic acid. No coagulum forms on addition of the acid solution to the latex. The thickness of the coagulated polymer sheet and conditions of washing the sheet are identical to Example 4. Alkaline reserve of the dried polymer is 1.55 meq. of HCl per 100 g. of polymer.
EXAMPLE 6
Latex B is acidified with a solution formed by mixing together 74.8 g. glacial acetic acid, 229 g. of the mixture of toluenesulfonic acid and xylenesulfonic acid described in Example 5, 25 g. dodecylbenzenesulfonic acid, and 612 g. water. During addition of the acid solution to the latex, a small quantity of coagulum forms which amounts to 0.006% of the latex. The polymer is washed and dried as in Example 5. Its alkaline reserve is 0.82 meq. of HCl per 100 g. of polymer.
Comparison of Examples 5 and 6 with Example 4 again demonstrates the control of alkaline reserve without changing the conditions of the washing step.
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Acidification of an alkaline chloroprene polymer latex to a pH of about 5.0-6.5 with a mixture of oxalic acid or a defined sulfonic acid and a weak carboxylic acid prior to polymer isolation by coagulation on a freeze drum eliminates or simplifies the polymer washing step after freeze drum isolation. The proportions of strong and weak acids can be so chosen that the isolated polymer will have the desired alkaline reserve even when the washing step is omitted. The plant production rate can thus be increased. Alternatively, for a given set of washing conditions and film thickness, any alkaline reserve within the desired range can be obtained.
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BACKGROUND OF INVENTION
This invention relates generally to fusion of polyolefin pipes and more particularly concerns the machines used to perform the pipe fusion process.
Fusion of small diameter pipe may usually be accomplished by hand-held, stand-mounted or cart-carried fusion devices. Little, if any, heavy equipment is necessary in the performance of the fusion process. Sticks of small diameter pipe are typically manually loaded through the top or end of the device for fusion. The fusion device can often be manually disconnected and removed from the pipeline or, at worst, the pipeline is manually released and pulled from the device manually or using a relatively small motorized vehicle.
Fusion of large diameter pipe typically requires fusion machines mounted on wheeled carts or motorized vehicles and the pipe sticks and pipelines are loaded and unloaded using various types of heavy equipment. A first pipe stick is loaded onto the top of lower fixed half jaws and upper half jaws pivoted on the lower half jaws, usually manually, to clamp the first pipe stick to the fixed jaws. A second pipe stick is loaded onto the top of lower sliding half jaws and upper half jaws are pivoted on the lower jaws, usually manually, to clamp the second pipe stick to the sliding jaws. Once the fusion process is completed and the fixed and sliding jaws are opened, the fused pipeline is pulled to position the free end of second stick in the fixed jaws and a third stick is loaded onto the sliding jaws for fusion into the pipeline. The equipment for loading the pipe sticks onto the sliding jaws and pulling the pipeline from the fixed jaws is likely very heavy and expensive and requires additional operators.
It is, therefore, an object of this invention to provide a pipe fusion machine which reduces the need for use of additional heavy pipe-handling equipment in performance of the pipe fusion process. And it is an object of this invention to provide a pipe fusion machine which simplifies the pipe-handling steps of the pipe fusion process.
SUMMARY OF INVENTION
In accordance with the invention, a machine for fusing polyolefin pipes has an upper half jaw, lower left and right complemental jaws, left and right pivots and at least one, and preferably left and right, actuators. The upper half jaw has an inside radius that is substantially equal to the selected outside radius of the pipes being fused. The lower left and right complemental jaws each have an inside radius that is substantially equal to the inside radius of the upper half jaw. The left and right pivots connect the lower left and right complemental jaws to their respective left and right portions of the half jaw. The left and right actuators are connected between the lower left and right complemental jaws and their respective left and right portions of the half jaw. Operation of the actuators in one direction causes the lower left and right complemental jaws to rotate to an opened condition in which the upper half jaw can be lowered onto and lifted from the pipes to be fused. Operation of the actuators in its other direction causes the lower left and right complemental jaws to rotate to a closed condition in which the pipes to be fused are gripped so substantially around their circumferences as to resist their deformation from round during manipulation by the machine and resist axial slippage during fusion.
The machine may also include at least one replacement set of lower left and right complemental jaws. Each of the replacement sets is interchangeable with the lower left and right complemental jaws and with each other. Each replacement set has a different inside radius and their inside radii are each different than the inside radius of the upper half jaw. For each replacement set of complemental jaws, at least one insert is provided that can be mounted on the inside radius of the upper half jaw. The inside radius of the insert or inserts associated with a set of complemental jaws is substantially equal to the inside radius of that set of complemental jaws. Thus, each replacement set of complemental jaws and its corresponding half jaw inserts enables use of the same machine to handle pipes and/or pipelines of a different outside radius.
The free ends of the lower left and right complemental jaws and their replacement sets, if any, are tapered toward their respective inside radii to facilitate their closure beneath the pipe or pipeline lying on the ground during pick-up.
Each actuator preferably includes a piston cylinder and a linkage that are serially connected between the lower left and right complemental jaws and the left and right portions of the half jaw, respectively. Each linkage preferably includes a toggle and a link. The toggle is pivoted at a first axis on the upper half jaw. It is also pivotally connected at a second axis to a piston of its respective cylinder and at a third axis to one end of a link. The other end of the link is pivotally connected at a fourth axis to a complemental jaw hub which is pivoted on the lower portion of the upper half jaw. The complemental jaw is attached to and moves in unison with the complemental jaw hub. The axes are parallel and the linkage provides such a mechanical advantage between its respective cylinder and complemental jaw as to assure that sufficient resistance to deviation of the pipeline or pipe stick from round during manipulation by the machine is maintained as long as the grip is closed on the pipeline or pipe stick and to resist axial slippage.
The machine preferably includes a gantry, a pair of spaced apart tracks and telescoping legs mounted at the front and rear of each track and supporting the gantry above the tracks. A carriage mounted on the gantry has spaced parallel guide rods. One upper half jaw is mounted for reciprocal sliding on the guide rods toward and away from another upper half jaw which is fixed on the guide rods. Another set of lower left and right complemental jaws, each having an inner radius substantially equal to the inner radius of said upper half jaw, is connected by another set of left and right pivots to their corresponding other left and right portions of the other half jaw. Another actuator, and preferably another set of left and right actuators, are each connected between their corresponding other lower left and right complemental jaws and left and right portions of the other half jaw, respectively. One direction of operation of the other left and right actuators causes the other lower left and right complemental jaws to simultaneously rotate to an opened condition in which the other upper half jaw can be lowered onto and lifted from the pipes to be fused. The other direction of operation of the other left and right actuators causes the other lower left and right complemental jaws to rotate to a closed condition in which the pipes to be fused are gripped so substantially around their circumferences as to resist deformation thereof from round during manipulation by the machine.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:
FIG. 1 is a front elevation view of a fusion machine according to the invention;
FIG. 2 is a perspective view of the machine of FIG. 1 ;
FIG. 3 is a top plan view of the carriage of the machine of FIG. 1 ;
FIG. 4 is a perspective view of the machine of FIG. 1 gripping a pipe stick/pipeline;
FIG. 5A is a front elevation view of a fully opened jaw of the machine of FIG. 1 positioned over a pipe/pipeline;
FIG. 5B is a front elevation view of the jaw of FIG. 5A lowered and partially closed at ground level on the pipe/pipeline;
FIG. 5C is a front elevation view of the jaw of FIG. 5A fully closed on the pipe/pipeline;
FIG. 6A is a perspective assembly view of a complemental jaw and a complemental jaw adapter hub of the machine of FIG. 1 ;
FIG. 6B is a perspective view of the complemental jaw and complemental jaw adapter hub of FIG. 6A assembled;
FIG. 7A is a front elevation view of a fully opened jaw of the machine of FIG. 1 modified by replacement complemental jaws and half jaw inserts and positioned over a pipe/pipeline;
FIG. 7B is a front elevation view of the jaw of FIG. 7A lowered and partially closed at ground level on the pipe/pipeline;
FIG. 7C is a front elevation view of the jaw of FIG. 7A fully closed on the pipe/pipeline;
FIG. 8A is a front elevation assembly view of the jaw of FIG. 7A ;
FIG. 8B is an enlarged front elevation view of the area BB of FIG. 8E ;
FIG. 8C is an enlarged front elevation view of the area CC of FIG. 8E ;
FIG. 8D is an enlarged perspective assembly view of the upper half jaw and inserts of FIG. 8A ;
FIG. 8E is a front elevation view of the jaw of FIG. 8A assembled;
FIG. 9A is a front elevation view illustrating the operation of the cylinders/pistons and linkages of the jaw of FIG. 7A to open the jaw;
FIG. 9B is a front elevation view illustrating the operation of the cylinders/pistons and linkages of the jaw of FIG. 7A to close the jaw;
FIG. 9C is a front elevation view illustrating the operation of the cylinders/pistons and linkages of the jaw of FIG. 7A to tightly grip the pipe/pipeline; and
FIG. 10 is a schematic diagram of the hydraulic system of the machine of FIG. 1 .
While the invention will be described in connection with a preferred embodiment thereof, it will be understood that it is not intended to limit the invention to that embodiment or to the details of the construction or arrangement of parts illustrated in the accompanying drawings.
DETAILED DESCRIPTION
The Machine
Looking first at FIGS. 1 and 2 , a track-driven pipe fusion machine 10 is configured to be top-loaded onto a pipe stick S and onto a pipeline L to which the stick is to be fused.
The machine 10 has a gantry 20 which is transported on a pair of parallel tracks 21 to travel along the pipeline path terrain. Telescoping cylinder legs 23 , 25 , 27 and 29 connected to the gantry 20 at each of its corners are operable to vary the gantry's elevation and level in relation to the terrain. A carriage assembly 30 including jaws 60 for grabbing the pipeline L and pipe stick S during the fusion process is suspended from and changes elevation and level with the gantry 20 .
The machine 10 performs the fusion process while stopped in a position in which the tracks 21 straddle and the gantry 20 spans across the pipeline L and the pipe stick S. The jaws 60 are used to pick up, manipulate and release the pipeline L and a pipe stick S during the fusion process.
The jaws 60 are opened and closed in response to actuators 110 which assure that sufficient resistance to deviation of the pipeline L and/or pipe stick S from round during manipulation by the machine 10 is maintained as long as the grip is closed on the pipeline L and/or pipe stick S and prevent axial slippage.
The machine 10 also includes an operator's platform 11 and control center 13 , a facer assembly 15 and a heater assembly 17 for performance of the fusion process steps.
The Carriage Assembly
Turning to FIGS. 3 and 4 , at least one fixed jaw 31 is mounted on the rear end of the carriage assembly 30 for handling the pipeline L. Two sliding jaws 32 and 33 are mounted on the carriage assembly 30 for handling the pipe stick S. A fourth jaw 34 can be selectively connected for operation either as a second fixed or as a third sliding jaw. The carriage assembly 30 as shown in an exemplary 2×2 configuration in which the first 31 and fourth 34 jaws are fixed and the second 32 and third 33 jaws are sliding in unison. As best seen in FIG. 4 , in this configuration the fixed jaws 31 and 34 will usually be used to grip the pipeline L and the sliding jaws 32 and 33 will usually be used to grip the pipe stick S. In a 3×1 configuration (not shown), the first jaw 31 is fixed and the second, third and fourth jaws 32 , 33 and 34 are sliding in unison. In the 3×1 configuration the single fixed jaw 31 will usually be used to grip the pipeline L and the three sliding jaws 32 , 33 and 34 will usually be used to grip the pipe stick S. This is especially useful if the pipe stick S is to be connected to a T-junction in a pipeline, in which case the length of the T may be too short for a multiple jaw grip. The principles herein disclosed are applicable to both the 2×2 and the 3×1 configurations of the carriage assembly 30 .
In the 2×2 configuration shown, the carriage 30 has a guide rod support plate 35 at its forward end and the outboard fixed jaw 31 at its aft end. Guide rods 37 extend in parallel and are fixed between the plate 35 and the outboard fixed jaw 31 . The support plate 35 has a central aperture 39 for connection to a mounting link 41 on the forward end of the gantry 20 . The fixed jaw 31 has lugs 43 symmetrically positioned and engagable on the aft end of the gantry 20 . The sliding jaws 32 and 33 are mounted on the forward portion of the guide rods 37 and are fixed against the opposite ends of the carriage cylinders 45 so that the sliding jaws 32 and 33 and the cylinders 45 move in unison on the guide rods 37 . The fourth jaw 34 is mounted between the outboard fixed jaw 31 and the inboard sliding jaw 32 but is fixed in relation to the outboard fixed jaw 31 by jaw conversion links 47 . The piston rods 49 of the carriage cylinders 45 extend through the inboard sliding jaw 32 and are fixed by rod extensions 51 to the first jaw 31 . Thus, when the pistons 49 are retracted in the cylinders 45 , the sliding jaws 32 and 33 move toward the fixed jaws 31 and 34 and, when the piston rods 49 are extended from the cylinders 45 , the sliding jaws 32 and 33 move away from the fixed jaws 31 and 34 .
In the 3×1 configuration, the jaw conversion links 47 connect the fourth jaw 34 to the inboard sliding jaw 32 and the rod extensions 51 extend through the fourth jaw 34 and are fixed to the fixed jaw 31 .
The Jaws
Turning to FIGS. 5A , 5 B and 5 C, each carriage assembly jaw 60 , whether fixed or sliding, includes an upper half jaw 61 , lower left 63 and right 65 complemental jaws and left 67 and right 69 pivots. In this disclosure, the upper half jaw 61 is so-called because, as shown, it substantially affords 180° of the grip. The lower jaws 63 and 65 as shown are quarter or 90° grips, but need not necessarily be quarter or 90° jaws. They are referred to as complemental because, as shown, they substantially afford the remaining 180° to complete the circular grip. In the quarter jaw embodiment shown, the complemental jaws are symmetric with respect to the center plane 73 , but in non-quarter jaw embodiments the complemental jaws will not by symmetric. The upper half jaw 61 has a generally trapezoidal outer perimeter 71 and is symmetric in relation to a vertical plane 73 through the center longitudinal axis 75 of the pipeline L and pipe stick S to be grasped. As best seen in FIG. 5C , it has an inside radius 77 that is substantially equal to the selected outside radius of the pipeline L and pipe stick S being fused.
For the purposes of this description, assume that the pipeline L or pipe stick S of FIGS. 5A , 5 B and 5 C have a two meter outside diameter and the upper half jaw 61 , therefore, has a one meter inside radius. As best seen in FIG. 5C , the complemental jaws 61 and 63 each have an inside radius 79 that is substantially equal to the inside radius of the upper half jaw 61 , in this example also one meter.
As best seen in FIG. 5B , the outer perimeters of the complemental jaws 63 and 65 are tapered toward their free ends to facilitate their insertion between the lower half of the pipe stick S or pipeline L and the ground G to pick up the pipe stick S or pipeline L. As shown, the tapers increase incrementally toward the tips of the complemental jaws 63 and 65 so as to converge toward their respective inside radii 79 .
Continuing to look at FIGS. 5A , 5 B and 5 C, the complemental jaws 63 and 65 have adapter hubs 81 at their upper ends. As best seen in FIGS. 6A and 6B , the left hub 81 has a hook 83 on its inside portion and a clevis 85 on its outside portion with lands 87 on the bottom of the clevis 85 . The left complemental jaw 63 has a retaining pin 89 on its upper inside portion and a stop plate 91 on its upper outside portion. The left complemental jaw 63 is attached to the left hub 81 by seating the retaining pin 89 in the hook 83 and securing the stop plate 91 in abutment with the lands 87 on the clevis 85 using screws 93 extending through the stop plate 91 and into the clevis 85 . The left hub 81 is pivoted for rotation on the lower portion of the left upper half jaw 61 about a shaft 95 on the left upper half jaw 61 and the left complemental jaw 63 pivots in unison with the left hub 81 to which it is attached. The right hub 81 and complemental jaw pivot 69 configuration mirrors the left hub 81 and complemental jaw pivot 69 configuration of FIGS. 6A and 6B .
As seen in FIGS. 7A , 7 B and 7 C, the machine may also include at least one replacement set 160 of lower left 163 and right 165 complemental jaws. Each replacement set 160 of complemental jaws 163 and 165 has a different inside radius 179 than the two meter diameter set 60 discussed above and the other replacement sets 160 . Assume that the pipeline L or pipe stick S of FIGS. 7A , 7 B and 7 C have a 54″ outside diameter and the upper half jaw 61 , therefore, has a 27″ inside radius 77 . As best seen in FIG. 7C , the lower left and right complemental jaws 163 and 165 each have an inside radius 179 that is substantially equal to the inside radius of the upper half jaw inserts 180 , in this example also 27″. For this replacement set 160 of complemental jaws 163 and 165 , at least one, and as shown two, inserts 180 are provided that are mountable on the inside radius 77 of the upper half jaw 61 . The lower complemental jaw FIGS. 6A and 6B for replacements 160 are installed as explained above in relation to the complemental jaws 63 and 65 of the two meter outside diameter pipeline L and pipe sticks S.
Installation of the inserts 180 for the upper half jaw 61 is illustrated in FIGS. 8A , 8 B, 8 C, 8 D and 8 E in relation to the 27″ outside radius pipeline L and pipe sticks S. As seen in FIG. 8A , two inserts 180 are used to change the inside radius 77 of the upper half jaw 61 . Looking at FIG. 8B , an L-shaped retainer 181 extends outward from the insert 180 for engagement against a bar 183 on the half jaw 61 . Turning to FIG. 8C , once the insert retainer 181 is engaged against the half jaw bar 183 , a latch 185 on the insert 180 slides into and out of engagement with a catch 187 on the half jaw 61 to secure or release the insert 180 to or from the half jaw 61 , respectively. As seen in FIG. 8E , the inside radius 189 of the inserts 180 associated with a set of complemental jaws 160 is substantially equal to the inside radius 79 of that set of complemental jaws 160 . Thus, each set of corresponding complemental jaws 160 and half jaw inserts 180 enables use of the same machine 10 to handle pipe sticks S and pipelines L of a different outside radius.
In this exemplary application, the pipeline L or pipe sticks S of FIGS. 7A , 7 B and 7 C have 54″ outside diameters. The upper half jaw 61 and its associated replacement lower complemental jaws 163 and 165 will, therefore, have one or more, and as shown, two inserts 180 defining a 27″ inside radius.
As seen in FIGS. 7A , 7 B and 7 C, the free ends of the replacement sets 160 of lower left and right complemental jaws 163 and 165 are, similar to the two meter diameter complemental jaws 63 and 65 , tapered toward their respective inside radii 179 to facilitate their closure beneath the pipe sticks S or pipeline L during pick-up.
The two meter (78.7″) and 54″ pipe diameters have been chosen for FIGS. 5A-C and 7 A-C, respectively, because it is presently anticipated that the same fusion machine 10 will be useful for fusing pipes of any diameter within that range. However, fusion machines applying the principles herein taught can be made in many different sizes to accommodate different ranges of pipe diameters.
The Actuators
Turning to FIGS. 9A , 9 B and 9 C, the left and right actuators 110 are connected between the replacement lower left and right complemental jaws 163 and 165 and their respective left and right portions of the half jaw 61 . As shown, the left and right actuators 110 are mirrored in relation to the plane 73 . Each actuator 110 includes a cylinder 111 and piston 113 and a linkage 120 serially connected between their respective lower replacement left and right complemental jaws 163 and 165 and left and right portions of the half jaw 61 . Each linkage 120 preferably includes a toggle 121 and a link 123 . The toggle 121 is pivoted at a first axis 125 on the upper half jaw 61 . It is also pivotally connected at a second axis 127 to the piston 113 of its respective cylinder 111 and at a third axis 129 to one end of the link 123 . The link 123 is also pivotally connected at a fourth axis 131 at its other end to the complemental jaw adapter hub 81 which is pivotally mounted at a fifth axis 133 on the lower portion of the upper half jaw 61 . The replacement complemental jaw 163 or 165 is secured to and moves in unison with its respective complemental jaw hub 81 as explained in relation to FIGS. 6A and 6B and the complemental jaws 63 and 65 . The axes 125 , 127 , 129 , 131 and 133 are parallel.
When an actuator piston 113 is retracted into its cylinder 111 , its toggle 121 is pivoted on the first axis 125 toward the cylinder 111 . The toggle 121 pulls the link 123 in tension, causing its complemental jaw hub 81 to rotate about its pivot axis 97 . The replacement complemental jaw 163 or 165 moves in unison with its hub 81 , opening the complemental jaw 163 or 165 . When an actuator piston 113 is extended from its cylinder 111 , its toggle 121 is pivoted on the first axis 125 away from the cylinder 111 . The toggle 125 pushes the link 123 in compression, causing its complemental jaw hub 81 to rotate about its pivot axis 133 . The complemental jaw 163 or 165 moves in unison with its hub 81 , closing the complemental jaw 163 or 165 . The linkage 120 provides such a mechanical advantage between its respective cylinder 111 and complemental jaw 163 or 165 as to assure that sufficient resistance to deviation of the pipeline L and/or pipe stick S from round during manipulation by the machine 10 is maintained as long as the grip is closed on the pipeline L and/or pipe stick S and that it resists axial slippage.
Hydraulic System
Turning to FIG. 10 , the machine hydraulic system 140 includes an engine 141 , preferably an industrial liquid cooled diesel engine, closed loop track drive pumps 143 , an auxiliary open loop pump 145 and a hydraulic fluid reservoir 147 . The system 140 powers right and left track motors 149 to drive and steer the machine 10 from one fusion location to another and into operating positions in which the machine 10 can pick up, manipulate and/or fuse pipeline L and pipe sticks S. The elevation and level of the gantry 20 is varied by simultaneous operation of the two front gantry telescoping cylinders 23 and 25 and independent operation of the two rear gantry telescoping cylinders 27 and 29 to raise and lower the corners of the gantry 20 as necessary. The spacing of the fixed and sliding jaws 60 is controlled by operation of the carriage cylinders 45 to reciprocate the sliding jaws on the guide rods 37 . The fusion machine jaws 60 are opened and closed by operation of their respective actuator cylinders 31 a and 31 b , 34 a and 34 b , 32 a and 32 b and 33 a and 33 c . As seen in FIGS. 9A , 9 B and 9 C, operation of the actuator cylinders 111 in one direction causes the lower left and right complemental jaws 63 and 65 or replacements 163 and 165 to rotate to an opened condition in which the upper half jaw 61 can be lowered onto and lifted from the pipe sticks S and/or pipeline L to be fused. Operation of the cylinders 111 in the opposite direction causes the lower left and right complemental jaws 63 and 65 or replacements 163 and 165 to rotate to a closed condition in which the pipe sticks S and/or pipeline L to be fused are gripped so substantially around their circumferences as to resist their deviation from round during manipulation by the machine 10 and to prevent slippage. The machine may also include a number of stripper cylinders 151 for use in removal of the heater during separation of the jaws after heating.
Operation
Assume for the exemplary application herein described that several sticks S of pipe to be fused into a pipeline L are in end-to-end alignment with the pipeline L, that the jaws 60 of the fusion machine 10 have been equipped with complemental jaws 63 and 65 or replacements 163 and 165 and half jaw inserts 180 corresponding to the pipe outer diameter and that the fourth jaw 34 , if any, has been secured for operation in the 2×2 configuration. Assume further that it is desirable that the pipeline L be manipulated by the fixed jaws 31 and 34 and the pipe stick S be manipulated by the sliding jaws 32 and 33 .
In performing the fusion process, the operator opens the complemental jaws 63 and 65 or replacements 163 and 165 to a fully opened configuration and adjusts the gantry 20 to a level suitable for the pipe stick S to be received in the carriage assembly 30 . The operator then drives the machine 10 into a position in which the tracks 21 straddle, the gantry 20 spans across and the carriage assembly 30 is aligned with the pipe stick S to be fused with the sliding jaws 32 and 33 proximate the end of the pipe stick S to be fused.
In this position, the operator lowers the gantry 20 and begins closing the sliding complemental jaws 63 and 65 or 163 and 165 as the tips drop below the midpoint of the pipe stick circumference. Lowering of the gantry 20 can, but need not necessarily, continue until the tips of the complemental jaw 63 and 65 or 163 and 165 contact the ground G. Closing of the complemental jaws 63 and 65 or 163 and 165 continues until they are in the fully closed condition. At this point, the complemental jaws 63 and 65 or 163 and 165 and half jaw 61 , or half jaw inserts 180 , if necessary, tightly grip the pipe stick S.
Once the pipe stick S is gripped, the gantry 20 can be raised, if necessary, to lift the gripped end of the pipe stick S above ground G. The operator can then drive the machine 10 and further change the elevation of the gantry 20 to a condition in which the gripped end of the pipe stick S is proximate, higher than and in longitudinal alignment with the end of the pipeline L to which the pipe stick S will be fused and the fixed jaws 31 and 34 are aligned above the end of the pipeline L to which the pipe stick S will be fused.
In this position, the operator again lowers the gantry 20 and begins closing the fixed complemental jaws 63 and 65 or 163 and 165 as the tips of the fixed complemental jaws 63 and 65 or 163 and 165 drop below the midpoint of the pipeline circumference. Lowering of the gantry 20 can, but need not necessarily, continue until the tips of the complemental jaw 63 and 65 or 163 and 165 contact the ground G. Closing of the complemental jaws 63 and 65 or 163 and 165 continues until they are in the fully closed condition. At this point, the complemental jaws 63 and 65 or 163 and 165 and half jaw 61 , or half jaw inserts 180 , if necessary, tightly grip the pipeline L.
Once the pipeline L is gripped, the gantry 20 can be raised to lift the gripped ends of the pipe stick S and pipeline L above ground G to fusion level. With the center axes 75 of the pipeline L and pipe stick S longitudinally aligned at fusion level, the operator adjusts the spacing between the fixed 32 and 33 and sliding jaws 32 and 33 , if necessary, inserts the facer assembly 15 into a suitable facing position between the fixed 31 and 34 and sliding jaws 32 and 33 and closes the spacing to bring the pipeline L and pipe stick S into abutment with opposite sides of the facer.
After facing, the operator spreads the spacing between the fixed 31 and 34 and sliding jaws 32 and 33 , removes the facer assembly 15 from the space, prepares a heater assembly 17 for insertion between the ends of the pipeline L and pipe stick S to be fused, adjusts the spacing if necessary to receive the heater assembly 17 , inserts the heater assembly 17 into a suitable heating position between the fixed 31 and 34 and sliding 32 and 33 jaws and closes the spacing to bring the pipeline L and pipe stick S into abutment with opposite sides of the heater.
After heating, the operator spreads the spacing between the fixed 31 and 34 and sliding 32 and 33 jaws, removes the heater assembly 17 and closes the spacing to bring the molten ends of the pipeline L and pipe stick S together. This condition is maintained under force until the joint has cooled sufficiently.
Once the joint has cooled, the operator lowers the gantry 20 and opens all of the jaws 60 simultaneously to release the fused pipeline L to the ground G. This completes this exemplary fusion process for one pipe stick S. The operator can then raise the gantry 20 sufficiently to allow the machine 10 to be driven forward from the fused pipe stick S to another pipe stick S for repetition of the process.
In some applications, rather than the exemplary process as above described, it may be desirable to use the fusion machine 10 to bring the pipe sticks S into their end-to-end alignment with the pipeline L at the beginning of the process, and/or to secure the fourth jaw 34 to the sliding jaw 32 rather than to the fixed jaw 31 and/or to apply the fixed jaws 31 and 34 to the pipe stick S and sliding jaws 32 and 33 to the pipeline L.
The fusion process can be performed using known facer and heater assemblies 15 and 17 and methods for control of the relative axial movement of the sliding jaw or jaws with respect to the fixed jaws, examples of which are disclosed in U.S. Pat. No. 5,814,182, U.S. Pat. No. 6,021,832, U.S. Pat. No. 6,212,747 and U.S. Pat. No. 6,212,748.
Thus, it is apparent that there has been provided, in accordance with the invention, a straddle-mounted pipe fusion machine that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art and in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit of the appended claims.
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A fusion machine which can be top-loaded on very large polyolefin pipes and pipelines has jaws which consist of an upper half jaw and lower left and right complemental jaws which pivot on the half jaw. Left and right actuators connected between the complemental jaws and the half jaw operate in one direction to cause the complemental jaws to rotate to an opened condition in which the upper half jaw can be lowered onto and lifted from the pipes to be fused and in the other direction to cause the complemental jaws to rotate to a closed condition in which the pipes to be fused are gripped so substantially around their circumferences as to resist their deformation from round during manipulation by the machine. The top-loading machine minimizes the need for heavy equipment to load and unload pipe to and from the fusion machine.
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SUMMARY OF THE INVENTION
The present invention relates generally to a two position, straight line motion actuator and more particularly to a fast acting actuator which utilizes pneumatic energy against a piston to perform fast transit times between the two positions. The invention utilizes a pair of control valves to gate high pressure air to the piston and latching magnets to hold the valves in their closed positions until a timed short term electrical energy pulse excites a coil around a magnet to partially neutralize the magnet's holding force and release the associated valve to move in response to high pressure air from a pressure source to an open position. Stored pneumatic gases accelerate the piston rapidly from one position to the other position. During movement of the piston from one position to the other, intermediate pressure air fills a chamber applying an opposing force on the piston to slow the piston. As the piston slows, pressure builds and when the pressure reaches the source pressure, a relief valve arrangement releases part of this trapped air back to the source.
This actuator finds particular utility in opening and closing the gas exchange, i.e., intake or exhaust, valves of an otherwise conventional internal combustion engine. Due to its fast acting trait, the valves may be moved between full open and full closed positions almost immediately rather than gradually as is characteristic of cam actuated valves.
The actuator mechanism may find numerous other applications such as in compressor valving and valving in other hydraulic or pneumatic devices, or as a fast acting control valve for fluidic actuators or mechanical actuators where fast controlled action is required such as moving items in a production line environment.
Internal combustion engine valves are almost universally of a poppet type which are spring loaded toward a valve-closed position and opened against that spring bias by a cam on a rotating cam shaft with the cam shaft being synchronized with the engine crankshaft to achieve opening and closing at fixed preferred times in the engine cycle. This fixed timing is a compromise between the timing best suited for high engine speed and the timing best suited to lower speeds or engine idling speed.
The prior art has recognized numerous advantages which might be achieved by replacing such cam actuated valve arrangements with other types of valve opening mechanism which could be controlled in their opening and closing as a function of engine speed as well as engine crankshaft angular position or other engine parameters.
In copending application Ser. No. 021,195 entitled ELECTROMAGNETIC VALVE ACTUATOR, filed Mar. 3, 1987 in the name of William E. Richeson and assigned to the assignee of the present application, there is disclosed a valve actuator which has permanent magnet latching at the open and closed positions. Electromagnetic repulsion may be employed to cause the valve to move from one position to the other. Several damping and energy recovery schemes are also included.
In copending application Ser. No. 07/153,257, entitled PNEUMATIC ELECTRONIC VALVE ACTUATOR, filed Feb. 8, 1988 in the names of William E. Richeson and Frederick L. Erickson and assigned to the assignee of the present application there is disclosed a somewhat similar valve actuating device which employs a release type mechanism rather than a repulsion scheme as in the previously identified copending application. The disclosed device in this application is a truly pneumatically powered valve with high pressure air supply and control valving to use the air for both damping and as the primary motive force. This copending application also discloses different operating modes including delayed intake valve closure and a six stroke cycle mode of operation.
In copending application Ser. No. 07/153,155 filed Feb. 8, 1988 in the names of William E. Richeson and Frederick L. Erickson, assigned to the assignee of the present application and entitled PNEUMATICALLY POWERED VALVE AOTUATOR there is disclosed a valve actuating device generally similar in overall operation to the present invention. One feature of this application is that control valves and latching plates have been separated from the primary working piston to provide both lower latching forces and reduced mass resulting in faster operating speeds. This high speed of operation results in a somewhat energy inefficient device.
The present application and copending application Ser. No. 07/209,272 filed in the names of William E. Richeson and Frederick L. Erickson, assigned to the assignee of the present invention and filed on even date herewith address, among other things, improvements in operating efficiency over the above noted devices.
Other related applications all assigned to the assignee of the present invention and filed in the name of William E. Richeson on Feb. 8, 1988 are Ser. No. 07/153,262 entitled POTENTIAL-MAGNETIC ENERGY DRIVEN VALVE MECHANISM where energy is stored from one valve motion to power the next, and Ser. No. 07/158,154 entitled REPULSION ACTUATED POTENTIAL ENERGY DRIVEN VALVE MECHANISM wherein a spring (or pneumatic equivalent) functions both as a damping device and as an energy storage device ready to supply part of the accelerating force to aid the next transition from one position to the other. The entire disclosures of all five of these copending applications are specifically incorporated herein by reference.
In the present invention, like Ser. No. 153,155, the power or working piston which moves the engine valve between open and closed positions is separated from the latching components and certain control valving structures so that the mass to be moved is materially reduced allowing very rapid operation. Latching and release forces are also reduced. Those valving components which have been separated from the main piston need not travel the full length of the piston stroke, leading to some improvement in efficiency.
Among the several objects of the present invention may be noted the provision of a bistable fluid powered actuating device characterized by fast transition times and improved efficiency; the provision of a pneumatically driven actuating device which is tolerant of variations in air pressure and other operating parameters; the provision of an electronically controlled pneumatically powered valve actuating device having improved damping features; the provision of a valve actuating device where a modest sacrifice in operating speed yields a significant increase in efficiency; and the provision of improvements in a pneumatically powered valve actuator where the control valves within the actuator cooperate with, but operate separately from the main working piston. These as well as other objects and advantageous features of the present invention will be in part apparent and in part pointed out hereinafter.
In general, a bistable electronically controlled fluid powered transducer has an armature including an air powered piston which is reciprocable along an axis between first and second positions along with a control valve reciprocable along the same axis between open and closed positions. A magnetic latching arrangement functions to hold the control valve in the closed position while an electromagnetic arrangement may be energized to temporarily neutralize the effect of the permanent magnet latching arrangement to release the control valve to move from the closed position to the open position. Energization of the electromagnetic arrangement causes movement of the valve in one direction along the axis first forming a sealed chamber including a portion of the armature and thereafter allowing fluid from a high pressure source to enter the closed chamber and drive the armature in the opposite direction from the first position to the second position along the axis. The distance between the first and second positions of the armature is typically greater than the distance between the open and closed positions of the valve.
Also in general and in one form of the invention, a pneumatically powered valve actuator includes a valve actuator housing with a piston reciprocable inside the housing along an axis. The piston has a pair of oppositely facing primary working surfaces. A pair of air control valves are reciprocable along the same axis relative to both the housing and the piston between open and closed positions. A coil is electrically energized to selectively opening one of the air control valves to supply pressurized air to one of the primary working surfaces causing the piston to move. Each of the air control valves includes an air pressure responsive surface which urges the control valve, when closed, against a spring bias toward its open position and there may be an air vent located about midway between the extreme positions of piston reciprocation for dumping expanded air from the one primary working surface and removing the accelerating force from the piston. The air vent also functions to introduce air at an intermediate pressure to be captured and compressed by the opposite primary working surface of the piston to slow piston motion as it nears one of the extreme positions. A one-way pressure relief valving arrangement such as a reed valve or check valve vents the captured air back to a high pressure air source. The air vent supplies intermediate pressure air to one primary working surface of the piston to temporarily hold the piston in one of its extreme positions pending the next opening of an air control valve. The air control valve is uniquely effective to vent air from the piston for a short time interval and at essentially source pressure back to the source and to finally dump air at a pressure not greater than source pressure after damping near the end of a piston stroke.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a view in cross-section showing the pneumatically powered actuator of the present invention with the power piston latched in its leftmost position as it would normally be when the corresponding engine valve is closed;
FIGS. 2-9 are views in cross-section similar to FIG. 1, but illustrating component motion and function as the piston progresses rightwardly to its extreme rightward or valve open position; and
FIGS. 10 and 11 are views similar to FIG. 1, but illustrating certain modifications of the actuator.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawing.
The exemplifications set out herein illustrate a preferred embodiment of the invention in one form thereof and such exemplifications are not to be construed as limiting the scope of the disclosure or the scope of the invention in any manner.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The valve actuator is illustrated sequentially in FIGS. 1-9 to illustrate various component locations and functions in moving a poppet valve or other component (not shown) from a closed to an open position. Motion in the opposite direction will be clearly understood from the symmetry of the components. The actuator includes a shaft or stem 11 which may form a part of or connect to an internal combustion engine poppet valve. The actuator also includes a low mass reciprocable piston 13 and a pair of reciprocating or sliding control valve members 15 and 17 enclosed within a housing 19. The control valve members 15 and 17 are latched in one position by permanent magnets 21 and 23 and may be dislodged from their respective latched positions by energization of coils 25 and 27. The control valve members or shuttle valves 15 and 17 cooperate with both the piston 13 and the housing 19 to achieve the various porting functions during operation. The housing 19 has a high pressure inlet port 89, a low pressure outlet port 41 and an intermediate pressure port 43. The low pressure may be about atmospheric pressure While the intermediate pressure is about 10 psi. above atmospheric pressure and the high pressure is on the order of 100 psi. gauge pressure.
FIG. 1 shows an initial state with piston 13 in the extreme leftward position and with the air control valve 15 latched closed. In this state, the annular abutment end surface 29 is inserted into an annular slot in the housing 19 and seals against an o-ring 31. This seals the pressure in cavity 33 and prevents the application of any moving force to the main portion 13. In this position, the main piston 13 is being urged to the left (latched) by the pressure in cavity or chamber 85 which is greater than the pressure in chamber or cavity 37. In the position illustrated, annular opening 45 is in its final open position after having rapidly released compressed air from cavity 37 at the end of a previous leftward piston stroke.
When current flows in coil 25, the field of permanent magnet 21 is partially neutralized and source air pressure on face 49 forces the shuttle or control valve 15 leftwardly against the bias of wave washer 16.
In FIG. 2, the shuttle valve 15 has moved toward the left, for example, 0.05 in. while piston 13 has not yet moved toward the right. The air valve 15 has opened because of an electrical pulse applied to coil 25 which has temporarily neutralized the holding force on iron armature or plate 47 by permanent magnet 21. When that holding force is temporarily neutralized. air pressure in cavity 33 which is applied to the air pressure responsive annular face 49 of valve 15 causes the valve to open. Notice that unlike the abovementioned Ser. No. 153,155 application, the communication between cavity 61 and the low pressure outlet port 41 has not been interrupted by movement of the valve 15. This communication is maintained at all times by way of a series of openings such as 54 in control valve 15 It should also be noted that, before the valve clears the slot containing o-ring 31, the edge of air valve 15 has overlapped the piston 13 at 53 closing annular opening 45 of FIG. 1 creating a closed chamber to assure rapid pressurization and maximum acceleration of the piston 13.
FIG. 3 shows the opening of the air valve 15 to about 0.10 in. (2/3 of its total travel) and movement of the piston 13 about 0.025 in. to the right.
In FIG. 3, the high pressure air had been supplied to the cavity 37 and to the face 38 of piston 13 driving that piston toward the right. That high pressure air supply by way of cavity 37 to piston face 88 is cut off in FIG. 4 by the edge of piston 13 passing the annular abutment 55 of the housing 19. Piston 13 continues to accelerate, however, due to the expansion energy of the high pressure air in cavity 37. The right edge of piston 13 is about to cut off communication at 57 between the port 43 and chamber 35. Disk 47 is nearing the leftward extreme of its travel and is compressing air in the gap 61. Air control valve 15 has also compressed the wave washer 16. This offers a damping or slowing effort to reduce the end approach velocity and consequently reduce any impact of the air valve components with the stationary structure. The compression of wave washer 16 also stores potential energy to power the return of the control valve 15 to the closed position. The annular surface 62 which is shown as a portion of a right circular cylinder may be undercut (concave) or tapered (a conical surface) to restrict air flow more near one or both extremes of the travel of plate 47 to enhance damping without restricting motion intermediate the ends if desired.
The piston 13 is continuing to accelerate toward the right in FIG. 4 and the air valve 15 has nearly reached its maximum leftward open displacement. The valve will tend to remain in this position for a short time due to the continuing air pressure on the annular surface 49 from high pressure source 39. There is a bleeding of air between the annular air valve and the piston into chamber 63 which is decreasing the pressure differential across the air valve 15 and this will soon allow the magnetic attraction of the disk 47 by the permanent magnet 21 along with the restorative force from wave washer 16 to pull the air valve 15 back toward its closed position. The wave washer or spring 16 functions as a spring bias means to provide damping of air control valve motion as the air control valve approaches an open position and provides a restorative force to aid rapid return of the air control valve to a closed position. This air bleeding is complete and the motion apparent in FIG. 6. In the transition from FIG. 4 to FIG. 5, the main piston 13 has just closed off communication between chamber 35 and medium pressure port 43 and further rightward motion of the main piston will compress the air trapped in chamber 35 so that the piston will be slowed and stopped by the time it has reached its extreme right hand position.
In FIG. 8, the air valve 15 is still in its extreme leftward position. The air valve is designed to close at about the same time as the main piston arrives at its furthest right hand location. Also, in FIG. 5, the piston is continuing to compress the air in cavity 35 slowing its motion.
In FIG. 6, the air valve 15 is beginning to return to its closed position. The attractive force of the magnet 21 on the disk 47 and the force of wave washer 16 is causing the disk to move back toward the magnetic latch. Further rightward movement of the piston as depicted in FIG. 6, uncovers the partial annular slot 67 leading to intermediate pressure port 43 so that the high pressure air in chamber 36 has blown down to the intermediate pressure. In FIGS. 6 and 7, the continued piston motion and corresponding buildup of pressure in cavity 85 may cause the pressure in cavity 35 to exceed the source pressure in cavity 83. When this happens, reed valve 101 opens to vent this high pressure air back to the source by way of cavity 33. The reed valves 101 and 103 function to recapture part of the kinetic energy of the piston 13 when damping the piston motion by returning high pressure air to the source 33 rather than merely compressing air in the piston motion damping chamber 35 and then dumping that air to the atmosphere or to the intermediate pressure source.
In FIG. 7, the pressure in chamber 35 is at its maximum as set by the reed valve 101 and an annular opening is just beginning to form at 69 between the abutting corners of the piston 13 and air valve 17. This annular opening vents the high pressure air from chamber 85 just as the piston nears its right hand resting position to help prevent any rebound of the piston back toward the left.
It will be understood from the symmetry of the valve actuator that the behavior of the air control valves 15 and 17 in this venting or blow-down is, as are many of the other features such as the opening of reed valves 101 and 103, substantially the same near each of the opposite extremes of the piston travel. In each case, the air control valve, piston and a fixed portion of the housing cooperate to vent the damping air from the piston at the last possible moment and after any pressure exceeding that in chamber 33 has been recaptured while these same components cooperate at the beginning of a stroke to supply air to power the piston for a much longer portion of the stroke.
The damping of the piston motion near its right extremity is adjustable by controlling the intermediate pressure level at port 43 to effectively control the density of the air initially entrapped in chamber 35. If this intermediate pressure is too high, the piston will rebound due to the high pressure of the compressed air in chamber 35. If this pressure is too low, the piston will approach its end position too fast and may mechanically rebound due to metallic deflection or mechanical spring back. With the correct pressure, the piston will gently come to rest in its right hand position. A further final damping of piston motion may be provided during the last few thousandths of an inch of travel by a small hydraulic damper including a fluid medium filled cavity 73 and a small piston 75 fastened to and moving with the main piston 13. Near either end of the main piston travel, the small piston 75 enters a shallow annular restricted area 77 displacing the fluid therefrom and bringing the main piston to rest. Fluid, such as oil, may be supplied to the damping cavity 73 by way of inlet 85.
In FIG. 8, the air valve 15 is about midway along its return to its closed position. Final damping is almost complete as the pressure in chamber 35 is being relieved through the annular opening at 69 and through the opening 81 and channel 83 to the low pressure port 41 so that the pressure throughout chamber 85 is reduced to nearly atmospheric pressure. Note that valves 15 and 17 include a number of apertures such as 54 and 81 in their respective web portions allowing free air flow between chambers such as 35 and 83. In FIG. 8, the piston 13 is reaching a very low velocity, the damping is almost complete and the final damping by the small fluid piston 75 is underway.
The main piston 13 has reached its righthand extreme in FIG. 9 and air valve 15 has closed. The supply of high pressure air from the source 39 to chamber 37 and the surface 88 of piston 13 has long since been interrupted by piston edge 105 passing housing edge 55 The piston 13 is held or latched in the position shown by the intermediate pressure in chamber 37 from source 48 acting on piston face 38.
In FIG. 1, which corresponds to a valve-closed condition, there is a slight gap between the piston face 88 and the valve housing while in FIG. 9 with the valve open, no such gap is seen. This gap provides for somewhat greater potential travel of the piston 13 than needed to close the engine valve insuring complete closure despite differential temperature expansions and similar problems which might otherwise result in the engine valve not completely closing. It should also be noted in following the sequence of FIGS. 1-9 that due to the length of the annular valving surface 107 of piston 13 between the edges 105 and 109. the chamber 63 is never in communication with the high pressure source chamber 33. Chamber 63 is maintained at the outlet pressure of port 41 at all times contrary to the similar chamber in the aforementioned Ser. No. 158,155.
In each of the drawing figures there is illustrated a differentially controllable valving arrangement for controlling the thrust on the piston 13 including adjustable set screw 109 having a conical end surface 111 variably spaced from a similarly shaped seat 113 for supplying air from the pressurized source to the air control valves to compensate for variations in external forces opposing piston motion. Set screw 109 may be adjusted to vary the restriction between chamber 33 and channel 115 leading to control valve 15. The corresponding channel 117 leading to control valve 17 has a fixed restriction. The restriction tends to be self adjusting in the sense that if piston motion is opposed then the pressure driving the piston increases tending to correct for the increased opposition.
FIGS. 10 and 11 are similar to FIG. 1, but each illustrates a scheme wherein the pneumatic damping means is differentially adjustable to vary piston deceleration as the piston approaches one extremity relative to piston deceleration as the piston approaches the other extremity. The pneumatic damping means includes a volume varying adjustable member in FIG. 10, and, in FIG. 11, an adjustable member for controlling air escape from the pneumatic damping means.
In FIG. 10, a pair of adjustable set screws 119 and 121 seal corresponding holes leading to the chambers 36 and 35 respectively. Axial movement of one of these screws varies the volume of the piston motion damping chamber. When the piston is near the end of it a travel, this small volume becomes a significant part of the total volume of the damping chamber and a change in that volume has a significant effect on the chamber pressure and, therefore, on the damping force. For example, if set screw 121 is withdrawn increasing the volume of chamber 35, the opening of reed valve 101 (at peak or source pressure) will be delayed until the piston is closer to its rightmost position. A fine tuning of the damping motion at one extreme of piston travel relative to damping at the other extreme is therefore possible. Such a fine tuning may also be achieved by bleeding air from the damping chamber as in FIG. 11 rather than varying the volume of that chamber as in FIG. 10. In FIG. 11, a pair of needle valves 123 and 125 control air seepage from the damping chambers, thereby controlling the time at which peak pressure occurs.
Little has been said about the internal combustion engine environment in which this invention finds great utility. That environment may be much the same as disclosed in the abovementioned copending applications and the literature cited therein to which reference may be had for details of features such as electronic controls and air pressure sources. In this preferred environment, the mass of the actuating piston and its associated coupled engine valve is greatly reduced as compared to the prior devices. While the engine valve and piston move about 0.45 inches between fully open and fully closed positions, the control valves move only about 0.175 inches, therefor requiring less energy to operate. The air passageways in the present invention are generally large annular openings with little or no associated throttling losses.
From the foregoing, it is now apparent that a novel electronically controlled, pneumatically powered actuator has been disclosed meeting the objects and advantageous features set out hereinbefore as well as others, and that numerous modifications as to the precise shapes, configurations and details may be made by those having ordinary skill in the art without departing from the spirit of the invention or the scope thereof as set out by the claims which follow.
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A bistable electronically controlled pneumatically powered transducer for use, for example, as a valve mechanism actuator in an internal combustion engine is disclosed. The transducer has an armature including a piston which is coupled to an engine valve, for example. The piston is powered by a pneumatic source and includes pneumatic damping with a one-way return of air compressed beyond source pressure back to the air source as it nears its destination position. Air supplied to power the piston may be differentially controlled to compensate for asymmetric resistance to movement and the air damping may be differentially controlled to provide dissimilar damping at the two extremes of piston motion. The armature is held in each of its extreme positions by pneumatic pressure under the control of control valves which are in turn held in their closed positions by permanent magnet latching arrangements and are released therefrom to supply air to the piston to be pneumatically driven to the other extreme position by an electromagnetic arrangement which temporarily neutralizes the permanent magnetic field of the latching arrangement.
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TECHNICAL FIELD OF THE INVENTION
The present invention is directed, in general, to antenna systems and, more specifically, to an apparatus for easily mounting and adjusting an antenna on a pole or similar fixture.
BACKGROUND OF THE INVENTION
In recent years there has been a rapid growth in the use of wireless devices, including one-way and two-way pagers, cellular phones, personal communication services (PCS) systems, and personal computers (PCs) equipped with cellular modems or wireless network cards. To support this growth, wireless service providers have dramatically increased the amount and the density of wireless network infrastructure deployed nationwide.
The large number of subscribers and the many applications for wireless communications have created a heavy subscriber demand for RF bandwidth. To maximize usage of the available bandwidth, a number of multiple access technologies have been implemented to allow more than one subscriber to communicate simultaneously with each base transceiver station (BTS) in a wireless system. These multiple access technologies include time division multiple access (TDMA), frequency division multiple access (FDMA), and code division multiple access (CDMA). These technologies assign each system subscriber to a specific traffic channel that transmits and receives subscriber voice/data signals via a selected time slot, a selected frequency, a selected unique code, or a combination thereof.
To further augment the capacity of their wireless networks and provide coverage to greater numbers of subscribers, wireless service providers increasingly are using a larger number of smaller-sized cell sites to cover the same amount of territory. Since each cell site covers a relatively smaller geographical area, each cell site generally also encompasses a smaller number of subscribers, all other things being equal. This allows greater reuse of frequency bands, time slots and codes in FDMA, TDMA and CDMA wireless networks.
However, the use of a larger number of smaller cell sites also increases the infrastructure equipment required by a wireless network. For example, doubling the number of cells sites covering a particular territory generally doubles the number of base transceiver stations, the number of antennas, the number of antenna poles, and the like.
To offset increased infrastructure equipment requirements, wireless service providers seek to minimize the equipment cost, installation costs, and maintenance costs. The use of standard commodity equipment is encouraged. It also is particularly helpful to use infrastructure equipment that is multi-purpose, adaptable, quickly installed, and easy to disassemble and service.
Much of the antenna equipment that has been installed, however, is inflexible, difficult to maintain, and/or custom-made to fit specific systems. For instance, many base station antennas are mounted on fixed platforms that are rigidly or permanently attached to utility poles. This makes moving, replacing, and/or adjusting the antennas difficult and more expensive.
There is therefore a need in the art for improved antenna mounting equipment that is more adaptable and easier to maintain and adjust. In particular, there is a need for antenna mounting equipment that is simple to attach to, or detach from, a utility pole. More particularly, there is a need for antenna mounting equipment that uses standard parts, but which can be adapted for use with utility poles of varying diameters and cross-sectional shapes.
SUMMARY OF THE INVENTION
To address the above-discussed deficiencies of the prior art, it is a primary object of the present invention to provide an apparatus for mounting a plurality of antennas on a utility pole. The apparatus comprises 1) a plurality of brackets capable of encircling the utility pole and supporting the plurality of antennas, each of the plurality of brackets comprising a) at least one support arm capable of attaching to a first selected one of the plurality of antennas; and b) a faceplate capable of engaging a surface of the utility pole; and 2) a plurality of tightening means, each of the tightening means connecting a first selected one of the plurality of brackets and a second selected one of the plurality of brackets, wherein the plurality of tightening means are capable of drawing the plurality of brackets encircling the utility pole closer together, such that the faceplate of the each of the plurality of brackets is pressed more firmly against the surface of the utility pole.
Accordingly in one embodiment of the apparatus, the plurality of brackets comprise three brackets.
In an alternate embodiment of the apparatus, the plurality of brackets comprise four brackets.
In another embodiment of the apparatus, at least a portion of a surface of the faceplate capable of engaging the surface of the utility pole is covered by a layer of rubber.
In still another embodiment of the apparatus, at least a portion of a surface of the faceplate capable of engaging the surface of the utility pole is covered by ridges.
In yet another embodiment of the apparatus, at least a portion of a surface of the faceplate capable of engaging the surface of the utility pole is covered by sharp points.
In a further embodiment of the apparatus, at least a portion of a surface of the faceplate capable of engaging the surface of the utility pole has a rough texture capable of increasing friction with the surface of the utility pole.
In a still further embodiment of the apparatus, each of the plurality of brackets comprises a first support arm and a second arm, wherein the first support arm is capable of attaching to one side of the first selected antenna and the second support arm is capable of attaching to an opposing side of the first selected antenna.
In a yet further embodiment of the apparatus, the plurality of tightening means comprise a plurality of bolts.
In another embodiment of the apparatus, the first selected antenna is adjustably attached to the at least one support arm, such that the first selected antenna may be tilted with respect to the horizon in a plurality of positions.
The foregoing has outlined rather broadly the features and technical advantages of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they may readily use the conception and the specific embodiment disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.
Before undertaking the DETAILED DESCRIPTION, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, wherein like numbers designate like objects, and in which:
FIG. 1 illustrates a perspective view of an exemplary multi-sector antenna system according to one embodiment of the present invention; and
FIG. 2 illustrates an exploded perspective view of an exemplary multi-sector antenna system according to another embodiment of the present invention.
DETAILED DESCRIPTION
FIGS. 1 and 2 , discussed below, and the various embodiments used to describe the principles of the present invention in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the invention. Those skilled in the art will understand that the principles of the present invention may be implemented in any suitably arranged multi-sector antenna.
FIG. 1 illustrates a perspective view of multi-sector antenna system 20 according to one embodiment of the present invention. Multi-sector antenna system 20 comprises three individual sector antennas, namely antenna 21 , antenna 22 and antenna 23 , mounted on utility pole 10 . Multi-sector antenna system 20 is associated with a single base transceiver station (BTS) that serves a single cell site in a wireless network. Each of antennas 21 – 23 transmits and receives signals in a specified 120° arc around the cell site.
Antenna 21 is attached to utility pole 10 by means of upper bracket 31 and lower bracket 41 . Upper bracket 31 comprises two parts: attachment bracket 31 a and faceplate 31 b . Lower bracket 41 also comprises two parts: attachment bracket 41 a and faceplate 41 b . Attachment bracket 31 a comprises two support arms that extend outward from utility pole 10 to support antenna 21 . Attachment bracket 31 a is removably attached to an upper portion of antenna 21 . Attachment bracket 41 a also comprises two support arms that extend outward from utility pole 10 to support antenna 21 . Attachment bracket 41 a is removably attached to a lower portion of antenna 21 . Attachment brackets 31 a and 41 a are fixedly attached to faceplates 31 b and 41 b , respectively. Faceplates 31 b and 41 b connect to other faceplates associated with antennas 22 and 23 and are tightened into place to form a strong friction grip against utility pole 10 . To increase friction with utility pole 10 , the inner surfaces of faceplates 31 b and 41 b may be rubber coated, or covered by rough ridges or points, similar to the surface of a file or a rasp.
In a similar manner, antenna 22 is attached to utility pole 10 by means of upper bracket 32 and lower bracket 42 . Upper bracket 32 comprises attachment bracket 32 a and faceplate 32 b . Lower bracket 42 comprises attachment bracket 42 a and faceplate 42 b . Attachment bracket 32 a comprises two support arms that extend outward from utility pole 10 to support antenna 22 . Attachment bracket 32 a is removably attached to an upper portion of antenna 22 and attachment bracket 42 a is removably attached to a lower portion of antenna 22 . Faceplates 32 b and 42 b connect to other faceplates (e.g., faceplates 31 b , 41 b ) associated with antennas 21 and 23 and are tightened into place to form a strong friction grip against utility pole 10 . The inner surfaces of faceplates 32 b and 42 b also may be rubber coated, or covered by sharp ridges and/or points to give it a rough texture.
Finally, antenna 23 is attached to utility pole 10 by means of upper bracket 33 and lower bracket 43 (not visible). Upper bracket 33 comprises attachment bracket 33 a and faceplate 33 b (not visible). Lower bracket 43 comprises attachment bracket 43 a and faceplate 43 b (not visible). Attachment bracket 33 a is removably attached to an upper portion of antenna 23 and attachment bracket 43 a is removably attached to a lower portion of antenna 23 . Faceplates 33 b and 43 b connect to faceplates 31 b , 32 b , 41 b , and 42 b on antennas 21 and 22 and are tightened against utility pole 10 . As before, the inner surfaces of faceplates 33 b and 43 b also may be rubber coated, or covered by sharp ridges and/or points to increase friction with utility pole 10 .
The upper portion of antenna 21 is attached to attachment bracket 31 a by means of a bolt or dowel that is inserted through one of a plurality of holes in attachment bracket 31 a and into a corresponding upper side hole in antenna 21 . Antenna 21 may be tilted upward or downward with respect to the horizon by inserting the bolt or dowel through selected holes in attachment bracket 31 a . The lower portion of antenna 21 is attached to attachment bracket 41 a by means of a bolt or dowel that is inserted through an elongated slot (or hole) in attachment bracket 41 a and into a corresponding lower side hole in antenna 21 . The bolt in the slot in attachment bracket 41 a can slide up and down to accommodate different positions as antenna 21 is tilted up or down by selecting different holes in attachment bracket 31 a.
Antennas 22 and 23 may be positioned at different angles of downtilt in attachment brackets 32 a , 33 a , 42 a , and 43 a in a manner similar to that described above with respect to antenna 21 . To avoid redundancy, further explanation of the tilting operations of antennas 22 and 23 is omitted.
Upper brackets 31 , 32 , and 33 encircle utility pole 10 and are joined together by means of threaded bolts 51 in the flanges of faceplates 31 b , 32 b , and 33 b . Similarly, lower brackets 41 , 42 , and 43 encircle utility pole 10 and are joined together by means of threaded bolts 51 in the flanges of faceplates 41 b , 42 b , and 43 b . Antennas 21 – 23 may be mounted on utility poles 10 of varying diameters by tightening or loosening bolts 51 , thereby increasing or decreasing the gaps separating faceplates 31 b , 32 b , and 33 b and drawing the inner surfaces of faceplates 41 b , 42 b , and 43 b closer together. Tightening the bolts effectively reduces the circumference of any cylinder (i.e., pole) that may be inserted within the inner surfaces of the faceplates 41 b , 42 b , and 43 b.
Although three upper brackets 31 – 33 are used to attach the tops of antennas 21 – 23 to utility pole 10 and three lower brackets 41 – 43 are used to attach the bottoms of antennas 21 – 23 to utility pole 10 , different numbers of brackets may be used. For example, utility pole 10 may support four antenna units if the cell site in which utility pole 10 is located is divided into four (4) 90° sectors. In such a case, each antenna unit would be separated by four brackets at the top and four brackets at the bottom. Furthermore, there is no requirement that utility pole 10 have a circular cross-sectional area. For example, if utility pole 10 was hexagonal in its cross-sectional area, upper brackets 31 – 33 and lower brackets 41 – 43 may still be used to attach antennas 21 – 23 . If utility pole 10 is square in its cross-sectional area, a system of four upper brackets and four lower brackets may be used to attach four antenna units.
FIG. 2 illustrates an exploded perspective view of exemplary multi-sector antenna system 200 according to another embodiment of the present invention. For the purposes of brevity and clarity in explaining FIG. 2 , only antenna 23 is shown and described. However, antennas 21 and 22 are mounted on utility pole 10 in a manner similar to antenna 23 .
In FIG. 2 , the upper brackets and lower brackets used to attach antennas 21 – 23 are comprised of a single part, rather than two parts. The tops of antennas 21 – 23 are mounted on utility pole 10 by means of attachment brackets 131 – 133 , each of which has a flat faceplate portion that makes contact with utility pole 10 . For example, faceplate segment 177 of attachment bracket 132 makes contact with utility pole 10 when brackets 131 – 133 are tightened in place. The inner surface of faceplate segment 177 may be covered by a layer of rubber or by rough ridges or points in order to increase friction with utility pole 10 .
Similarly, the bottoms of antennas 21 – 23 are mounted on utility pole 10 by means of attachment brackets 141 – 143 , each of which has a flat faceplate portion that makes contact with utility pole 10 . For example, faceplate segment 176 of attachment bracket 142 makes contact with utility pole 10 when brackets 141 – 143 are tightened in place. The inner surface of faceplate segment 176 may also be covered by rubber or rough ridges/points in order to increase friction with utility pole 10 .
Bolt assemblies, including bolts 145 , 146 and 150 , are used to tighten together attachment brackets 131 – 133 and attachment brackets 141 – 143 . An exploded view is shown of a bolt assembly comprising bolt 150 , washers 151 – 153 , and nut 154 . Bolt 150 is inserted through slots in attachment brackets 131 and 133 . Depending on how large the slots are, bolt 150 may slide outward by varying amounts with respect to utility pole 10 in order to accommodate different pole diameters.
Antenna 23 is mounted on upper attachment bracket 133 and lower attachment bracket 143 by means of bolts 160 , 161 and 170 that are inserted through holes 181 in the support arms of upper attachment bracket 133 or through slots 182 in the support arms of lower attachment bracket 143 and then into corresponding sideholes 183 and 184 in antenna 23 . The bolt are secured in place with washers 171 and 172 .
Antenna 23 may be tilted upward or downward with respect to the horizon by inserting bolts 160 and/or 161 through different ones of holes 181 in upper attachment bracket 133 and then into sideholes 183 in antenna 23 . The lower portion of antenna 23 is rotatably mounted on lower attachment bracket 143 by means of bolt 170 , which is inserted through slot 182 in lower attachment bracket 143 and into corresponding sidehole 184 in antenna 23 . Bolt 170 can slide vertically and rotate in slot 182 to accommodate different positions as antenna 23 is tilted up or down by selecting different holes 181 in attachment bracket 133 .
The attachment brackets of the present invention provide a superior means for mounting antennas on a utility pole over the prior art. The attachment brackets accommodate poles of different diameters and may be attached using simple hand tools, such as wrenches. A technician may easily adjust the height at which antennas 21 – 23 are mounted on utility pole 10 by loosening bolts 145 / 146 / 150 in the upper and lower attachment brackets and then sliding the entire assembly up or down to the correct position. A technician also may easily adjust the tilt or antennas 21 – 23 by removing bolts 160 and 161 in the upper attachment bracket, tilting the antenna(s) to the correct angle, and then reinserting bolts 160 and 166 . The present invention also allows the antennas to be tilted independently.
Advantageously, the present invention obviates the need to modify or adapt the utility pole in any way in order to mount antennas thereon. The present invention can be quickly attached to different-sized utility poles that are part of the existing wireless infrastructure or to new utility poles without the need to drill, weld or otherwise alter the poles.
In alternate embodiments of the present invention, bolts 51 , 145 , 146 , and 150 may be replaced by other types of tightening means (or closure means) that secure the attachment brackets to the utility pole. For example, the attachment brackets may be mounted on the utility pole by means of a belt that is threaded through holes or slots in the attachment brackets and then is tightened, cinched or latched in place, similar to a radiator hose clamp.
Although the present invention has been described in detail, those skilled in the art should understand that they can make various changes, substitutions and alterations herein without departing from the spirit and scope of the invention in its broadest form.
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There is disclosed an apparatus for mounting antennas on a utility pole. The apparatus comprises a group of brackets that encircle the utility pole and support the antennas. Each bracket comprises at least one support arm capable of attaching to an antenna and a faceplate that presses against the surface of the utility pole. The apparatus also includes tightening or closure means, such as nut and bolt assemblies, that connect the brackets together. When tightened, the tightening means draw the brackets encircling the utility pole closer together, thereby pressing the faceplates of each bracket more firmly against the utility pole. This clamps the apparatus tightly in place at selected points on the utility pole.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S. Ser. No. 14/254,379 filed on Apr. 16, 2014; which is a continuation of U.S. Ser. No. 14/036,036 filed on Sep. 25, 2013 (now U.S. Pat. No. 8,703,081, with issue date Apr. 22, 2014); which is a continuation of U.S. Ser. No. 13/679,775 filed on Nov. 16, 2012 (now U.S. Pat. No. 8,545,778, with issue date Oct. 1, 2013); which is a continuation of U.S. Ser. No. 13/343,491 filed on Jan. 4, 2012 (now U.S. Pat. No. 8,313,323, with issue date Nov. 20, 2012); which is a continuation of U.S. Ser. No. 13/169,187 filed on Jun. 27, 2011 (now U.S. Pat. No. 8,114,368. with issue date Feb. 14, 2012); which is a continuation of U.S. Ser. No. 12/839,154 filed on Jul. 19, 2010 (now U.S. Pat. No. 7,988,939, with issue date Aug. 2, 2011); which is a continuation of U.S. Ser. No. 12/705,196 filed on Feb. 12, 2010 (now U.S. Pat. No. 7,776,301, with issue date Aug. 17, 2010); which is a continuation of U.S. Ser. No. 12/351,191 filed on Jan. 9, 2009 (now U.S. Pat. No. 7,674,442, with issue date Mar. 9, 2010); which is a continuation of U.S. Ser. No. 11/377,528 filed on Mar. 16, 2006 (now U.S. Pat. No. 7,507,083, with issue date Mar. 24, 2009); which claims the benefit of U.S. Provisional Application 60/662,911 filed on Mar. 17, 2005, the full disclosures of which are hereby incorporated by reference.
INTRODUCTION
[0002] The invention provides compositions and methods for reducing the levels of mercury emitted into the atmosphere upon burning of mercury containing fuels such as coal. In particular, the invention provides for addition of various halogen and other sorbent compositions into the coal burning system during combustion.
[0003] Significant coal resources exist around the world that are capable of meeting large portions of the world's energy needs into the next two centuries. High sulfur coal is plentiful, but requires remediation steps to prevent excess sulfur from being released into the atmosphere upon combustion. In the United States, low sulfur coal exists in the form of low BTU value coal in the Powder River basin of Wyoming and Montana, in lignite deposits in the North Central region of North and South Dakota, and in lignite deposits in Texas. But even when coals contain low sulfur, they still contain non-negligible levels of elemental and oxidized mercury.
[0004] Unfortunately, mercury is at least partially volatilized upon combustion of coal. As a result, the mercury tends not to stay with the ash, but rather becomes a component of the flue gases. If remediation is not undertaken, the mercury tends to escape from the coal burning facility, leading to environmental problems. Some mercury today is captured by utilities, for example in wet scrubber and SCR control systems. However, most mercury is not captured and is therefore released through the exhaust stack.
[0005] In the United States, the Clean Air Act Amendments of 1990 contemplated the regulation and control of mercury. A mercury study in the report to Congress in 1997 by the Environmental Protection Agency (EPA) further defined the bounds of mercury release from power plants in the United States. In December 2000, the EPA decided to regulate mercury, and have published proposed clean air mercury rules in January and March of 2004. A set of regulations for required mercury reduction from US coal burning plants has now been promulgated by the United States Environmental Protection Agency.
[0006] In addition to wet scrubber and SCR control systems that tend to remove mercury partially from the flue gases of coal combustion, other methods of control have included the use of activated carbon systems. Use of such systems tends to be associated with high treatment costs and elevated capital costs. Further, the use of activated carbon systems leads to carbon contamination of the fly ash collected in exhaust air treatments such as the bag house and electrostatic precipitators.
[0007] Mercury emissions into the atmosphere in the United States are approximately 50 tons per year. A significant fraction of the release comes from emissions from coal burning facilities such as electric utilities. Mercury is a known environmental hazard and leads to health problems for both humans and non-human animal species. To safeguard the health of the public and to protect the environment, the utility industry is continuing to develop, test, and implement systems to reduce the level of mercury emissions from its plants. In combustion of carbonaceous materials, it is desirable to have a process wherein mercury and other undesirable compounds are captured and retained after the combustion phase so that they are not released into the atmosphere.
SUMMARY
[0008] Processes and compositions are provided for decreasing emissions of mercury upon combustion of fuels such as coal. Various sorbent compositions are provided that contain components that reduce the level of mercury and/or sulfur emitted into the atmosphere upon burning of coal. In various embodiments, the sorbent compositions are added directly to the fuel before combustion; are added partially to the fuel before combustion and partially into the flue gas post combustion zone; or are added completely into the flue gas post combustion zone. In preferred embodiments, the sorbent compositions comprise a source of halogen and preferably a source of calcium. Among the halogens, iodine and bromine are preferred. In various embodiments, inorganic bromides make up a part of the sorbent compositions.
[0009] In various embodiments, mercury sorbent compositions containing bromine or iodine are added to the fuel as a powder or a liquid prior to combustion. Alternatively, the sorbent compositions containing halogen, such as bromine and iodine, are injected into the flue gas at a point after the combustion chamber where the temperature is higher than about 1500° F. (about 800° C.).
[0010] In preferred embodiments, the sorbent compositions further contain other components, especially a source of calcium. Thus, in one embodiment, the invention provides for singular and multiple applications of multi-element oxidizers, promoters, and sorbents to coal prior to and/or after combustion in a furnace. In various embodiments, the components of the sorbent compositions develop ceramic characteristics upon combustion and subsequent calcination of the components with the carbonaceous materials. In various embodiments, use of the sorbent compositions reduces mercury emissions by capturing and stabilizing oxidized and elemental mercury with multiple-element remediation materials such as calcium oxides, calcium bromides, other calcium halogens, as well as oxides of silicon, aluminum, iron, magnesium, sodium, and potassium.
[0011] In preferred embodiments, mercury emissions from coal burning facilities are reduced to such an extent that 90% or more of the mercury in the coal is captured before release into the atmosphere. The mercury remediation processes can be used together with sorbent compositions and other processes that remove sulfur from the combustion gas steam. Thus in preferred embodiments, significant sulfur reduction is achieved along with 90% plus reduction of mercury emissions.
[0012] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
DESCRIPTION
[0013] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0014] In various embodiments, the invention provides compositions and methods for reducing emissions of mercury that arise from the combustion of mercury containing fuels such as coal. Systems and facilities that burn fuels containing mercury will be described with particular attention to the example of a coal burning facility such as used by electrical utilities. Such facilities generally have some kind of feeding mechanism to deliver the coal into a furnace where the coal is burned or combusted. The feeding mechanism can be any device or apparatus suitable for use. Non-limiting examples include conveyer systems, screw extrusion systems, and the like. In operation, a mercury-containing fuel such as coal is fed into the furnace at a rate suitable to achieve the output desired from the furnace. Generally, the output from the furnace is used to boil water for steam to provide direct heat, or else the steam is used to turn turbines that eventually result in the production of electricity.
[0015] The coal is fed into the furnace and burned in the presence of oxygen. Typical flame temperatures in the combustion temperature are on the order of 2700° F. to about 3000° F. After the furnace or boiler where the fed fuel is combusted, the facility provides convective pathways for the combustion gases, which for convenience are sometimes referred to as flue gases. Hot combustion gases and air move by convection away from the flame through the convective pathway in a downstream direction (i.e., downstream in relation to the fireball). The convection pathway of the facility contains a number of zones characterized by the temperature of the gases and combustion products in each zone. Generally, the temperature of the combustion gas falls as it moves in a direction downstream from the fireball. The combustion gases contain carbon dioxide as well as various undesirable gases containing sulfur and mercury. The convective pathways are also filled with a variety of ash which is swept along with the high temperature gases. To remove the ash before emission into the atmosphere, particulate removal systems are used. A variety of such removal systems can be disposed in the convective pathway such as electrostatic precipitators and a bag house. In addition, chemical scrubbers can be positioned in the convective pathway. Additionally, there may be provided various instruments to monitor components of the gas such as sulfur and mercury.
[0016] From the furnace, where the coal is burning at a temperature of approximately 2700° F.-3000° F., the fly ash and combustion gases move downstream in the convective pathway to zones of ever decreasing temperature. Immediately downstream of the fireball is a zone with temperature less that 2700° F. Further downstream, a point is reached where the temperature has cooled to about 1500° F. Between the two points is a zone having a temperature from about 1500 to about 2700° F. Further downstream, a zone of less than 1500° F. is reached, and so on. Further along in the convective pathway, the gases and fly ash pass through lower temperature zones until the baghouse or electrostatic precipitator is reached, which typically has a temperature of about 300° F. before the gases are emitted up the stack.
[0017] In various embodiments, the process of the present invention calls for the application of a mercury sorbent
[0018] directly to a fuel such as coal before combustion (addition “pre-combustion”);
[0019] directly into the gaseous stream after combustion in a temperature zone of between 2700° F. and 1500° F. (addition “post-combustion”); or
[0020] in a combination of pre-combustion and post-combustion additions.
[0021] In various embodiments, oxidized mercury from combustion reports to the bag house or electrostatic precipitator and becomes part of the overall ash content of the coal burning plant. Heavy metals in the ash do not leach below regulatory levels.
[0022] In various embodiments, mercury emissions from the coal burning facility are monitored. Depending on the level of mercury in the flue gas prior to emission from the plant, the amount of sorbent composition added onto the fuel per- and/or post-combustion is raised, lowered, or is maintained unchanged. In general, it is desirable to remove as high a level of mercury as is possible. In typical embodiments, mercury removal of 90% and greater are achieved, based on the total amount of mercury in the coal. This number refers to the mercury removed from the flue gases so that mercury is not released through the stack into the atmosphere. To minimize the amount of sorbent added into the coal burning process so as to reduce the overall amount of ash produced in the furnace, it is desirable in many environments to use the measurements of mercury emissions to reduce the sorbent composition rate of addition to one which will achieve the desired mercury reduction without adding excess material into the system.
[0023] Thus in one embodiment, a method is provided for burning coal to reduce the amount of mercury released into the atmosphere. The method involves first applying a sorbent composition comprising a halogen compound onto the coal. The coal is then delivered into the furnace of a coal burning plant. The coal containing the sorbent composition is then combusted in the furnace to produce ash and combustion gases. The combustion gases contain mercury, sulfur and other components. To accomplish a desired reduction of mercury in the combustion gases in order to limit release into the atmosphere, the mercury level in the combustion gases is preferably monitored by measuring the level analytically. In preferred embodiments, the amount of the sorbent composition applied onto the coal before composition is adjusted depending on the value of the mercury level measured in the combustion gases.
[0024] In another embodiment, a mercury sorbent is added into the coal burning system after combustion in a region having a temperature from about 1500° F. to 2700° F. (about 815° C. to 1482° C.). A method is provided for reducing the level of mercury released into the atmosphere upon combustion of coal that contains mercury. The combustion is carried out in a coal burning system containing a furnace and a convective pathway for the combustion gases. The method involves burning the coal in the furnace and injecting a sorbent containing a halogen into the convective pathway at a point where the combustion gases are at a temperature of 1500° F. to 2700° F. If desired, the level of mercury in the gases escaping the facility is monitored and measured. Depending on the level of mercury escaping from the facility, reflected in the value determined by monitoring, the rate of addition of the mercury sorbent can be increased, decreased, or maintained unchanged. In a further embodiment, a mercury sorbent containing a halogen can be both applied to the coal prior to combustion and injected into the convective pathway at a point where the combustion gases are at a temperature of 1500° F. to 2700° F.
[0025] Sorbent composition comprising a halogen compound contains one or more organic or inorganic compounds containing a halogen. Halogens include chlorine, bromine, and iodine. Preferred halogens are bromine and iodine. The halogen compounds noted above are sources of the halogens, especially of bromine and iodine. For bromine, sources of the halogen include various inorganic salts of bromine including bromides, bromates, and hypobromites. In various embodiments, organic bromine compounds are less preferred because of their cost or availability. However, organic sources of bromine containing a suitably high level of bromine are considered within the scope of the invention. Non-limiting examples of organic bromine compounds include methylene bromide, ethyl bromide, bromoform, and carbonate tetrabromide. Non-limiting sources of iodine include hypoiodites, iodates, and iodides, with iodides being preferred.
[0026] When the halogen compound is an inorganic substituent, it is preferably a bromine or iodine containing salt of an alkali metal or an alkaline earth element. Preferred alkali metals include lithium, sodium, and potassium, while preferred alkaline earth elements include beryllium, magnesium, and calcium. Of halogen compounds, particularly preferred are bromides and iodides of alkaline earth metals such as calcium.
[0027] The sorbent composition containing the halogen is provided in the form of a liquid or of a solid composition. When it is a liquid composition, the sorbent composition comprises preferably an aqueous solution of a bromine or iodine compound as described above. The methods of the invention that reduce the level of mercury released into the atmosphere upon combustion of coal involve applying the sorbent composition, in the form of either a liquid or a solid composition, into the coal burning process. In one embodiment, the sorbent composition is added to the coal prior to combustion, while in another the sorbent composition is injected into the convective pathway of the coal burning facility in a zone having a temperature of 1500° F. to 2700° F. In various embodiments, sorbent addition can take place both pre-combustion and post-combustion. In a preferred embodiment, an aqueous sorbent containing a halogen is sprayed onto the coal pre-combustion and the coal enters the furnace still wet with water.
[0028] In various embodiments, liquid mercury sorbent comprises a solution containing 5-60% by weight of a soluble bromine or iodine containing salt. Non-limiting examples of preferred bromine and iodine salts include calcium bromide and calcium iodide. In various embodiments, liquid sorbents contain 5-60% by weight of calcium bromide and/or calcium iodide. For efficiency of addition to the coal prior to combustion, in various embodiments it is preferred to add mercury sorbents having as high level of bromine or iodine compound as is feasible. In a non-limiting embodiment, the liquid sorbent contains 50% or more by weight of the halogen compound, such as calcium bromide or calcium iodide.
[0029] In various embodiments, the sorbent compositions containing a halogen compound further contain a nitrate compound, a nitrite compound, or a combination of nitrate and nitrite compounds. Preferred nitrate and nitrite compounds include those of magnesium and calcium, preferably calcium. Thus, in a preferred embodiment, the mercury sorbent composition contains calcium bromide. Calcium bromide can be formulated with other components such as the nitrates and nitrites discussed above and to either a powder sorbent composition or a liquid sorbent composition. The powder or liquid sorbent compositions containing halogen are added on to the coal pre-combustion, injected into the convective pathways of the coal burning facility in a zone having a temperature of about 1500° F. to about 2700° F., or a combination of the two.
[0030] The mercury sorbent compositions containing a halogen compound preferably further comprise a source of calcium. Non-limiting examples of calcium sources include calcium oxides, calcium hydroxides, calcium carbonate, calcium bicarbonate, calcium sulfate, calcium bisulfate, calcium nitrate, calcium nitrite, calcium acetate, calcium citrate, calcium phosphate, calcium hydrogen phosphate, and calcium minerals such as apatite and the like. Preferred sources of calcium include calcium halides, such as calcium bromide, calcium chloride, and calcium iodide. Organic calcium compounds can also be used. Non-limiting examples include calcium salts of carboxylic acids, calcium alkoxylates, and organocalcium compounds. As with the halogen compounds above, in various embodiments, the organic calcium compounds tend to be less preferred because of expense and availability.
[0031] In addition to the mercury sorbent composition added into the system before or after combustion, a sulfur sorbent composition may be added along with the mercury sorbent. Thus, in preferred embodiments, methods are provided for reducing both sulfur and mercury emissions in the flue gas upon combustion of coal containing sulfur and mercury. In a preferred embodiment, a method involves applying a first sorbent composition and a second sorbent composition into the system. One of the first and second sorbent compositions is added to the coal prior to combustion and the other is injected into the coal burning system in a zone of the convective pathway downstream of the burning chamber, preferably where the temperature is in the range of between 1500° F. to 2700° F. The first sorbent composition preferably contains a halogen component and is added at level effective to reduce mercury in the combustion gases. The second sorbent composition contains at least a calcium component and is added at level effective to reduce sulfur in the combustion gases.
[0032] In the embodiments of the previous paragraph, the first sorbent composition containing the halogen component comprises a halogen compound such as the preferred bromine and iodine compounds described above. The second sorbent composition contains calcium in a form suitable for the reduction of sulfur emissions from the burning coal system. The second sorbent composition containing a calcium component preferably contains calcium in a minimum molar amount of 1:1 based on the molar amount of sulfur present in the coal. Preferably, the level of calcium added to the system with the second sorbent composition is no greater than 3:1 with respect to moles of sulfur in the coal. Treatment at higher levels of calcium tends to waste material and risks blinding off the furnace, thereby impeding the combustion process and loading the particulate control system.
[0033] Essentially, it is desired to add the calcium-containing sulfur sorbent at a level effective to remove sulfur from the flue gases of the burning coal, but not in an over abundant amount that would lead to production of excess ash. The second sorbent composition containing a calcium component can contain any of the inorganic or organic calcium compounds noted above. In addition, various industrial products contain calcium at a suitable level, such as cement kiln dust, lime kiln dust, Portland cement, and the like. In various embodiments, the calcium-containing sulfur sorbent contains a calcium powder such as those listed, along with an aluminosilicate clay such as montmorillonite or kaolin. The calcium containing sulfur sorbent composition preferably contains sufficient SiO 2 and Al 2 O 3 to form a refractory-like mixture with calcium sulfate produced by combustion, such that the calcium sulfate is handled by the particle control system of the furnace. In preferred embodiments, the calcium containing sulfur absorbent contains a minimum of 2% silica and 2% alumina.
[0034] In a preferred embodiment, a mercury sorbent composition containing calcium and bromine is applied to the coal. In various embodiments, the sorbent composition contains calcium bromide. Alternatively, the absorbent composition contains a bromine compound other than calcium bromide and a calcium compound other than calcium bromide. Non-limiting examples of sources of calcium include calcium bromide, calcium nitrite, Portland cement, calcium oxide, calcium hydroxide and calcium carbonate. Then the coal containing the calcium and bromine sorbent composition is burned to produce ash and combustion gases. Desirably, the level of mercury in the combustion gases is measured and monitored. The level of bromine added to the coal by way of the sorbent composition is then adjusted up or down or left unchanged, depending on the level of mercury measured in the combustion gases. In various embodiments, the method further provides for measuring a level of sulfur in the combustion gases and adjusting the level of calcium added onto the coal based on the level of sulfur measured. In preferred embodiments, mercury emissions into the environment from the coal burning facility are reduced by 90% or more. As used in this application, a mercury reduction of 90% or more means at least 90% of the mercury in the coal being burned is captured to prevent its release into the atmosphere. Preferably, a sufficient amount of bromine is added onto the coal prior to combustion to reduce the mercury emissions into the environment by 90% or more.
[0035] In one aspect, the invention involves reducing the level of mercury emitted into the atmosphere from facilities that burn fuels containing mercury. A commercially valuable embodiment is use of the invention to reduce mercury emissions from coal burning facilities to protect the environment and comply with government regulations and treaty obligations. Much of the following discussion will refer to coal as the fuel; it is to be understood that the description of coal burning is for illustrative purposes only and the invention is not necessarily to be limited thereby.
[0036] In various embodiments, the methods of the invention involve adding a mercury sorbent into the fuel or coal burning system at treatment levels sufficient to cause a desired lowering of the levels of mercury escaping from the facility into the atmosphere upon combustion of the fuel. Suitable mercury sorbents are described above. In a preferred embodiment, the mercury sorbents contain a source of bromine and/or iodine, preferably in the form of inorganic bromide or iodide salts as discussed above.
[0037] In one embodiment, the mercury sorbent composition is added onto coal prior to its combustion. The coal is particulate coal, and is optionally pulverized or powdered according to conventional procedures. The sorbent composition is added onto the coal as a liquid or as a solid. Generally, solid sorbent compositions are in the form of a powder. If the sorbent is added as a liquid (usually as a solution of one or more bromine or iodine salts in water), in one embodiment the coal remains wet when fed into the burner. The sorbent composition can be added onto the coal continuously at the coal burning facility by spraying or mixing onto the coal while it is on a conveyor, screw extruder, or other feeding apparatus. In addition or alternatively, the sorbent composition may be separately mixed with the coal at the coal burning facility or at the coal producer. In a preferred embodiment, the sorbent composition is added as a liquid or a powder to the coal as it is being fed into the burner. For example, in a preferred commercial embodiment, the sorbent is applied into the pulverizers that pulverize the coal prior to injection. If desired, the rate of addition of the sorbent composition can be varied to achieve a desired level of mercury emissions. In one embodiment, the level of mercury in the flue gases is monitored and the level of sorbent addition adjusted up or down as required to maintain the desired mercury level.
[0038] Mercury levels can be monitored with conventional analytical equipment using industry standard detection and determination methods. In one embodiment, monitoring is conducted periodically, either manually or automatically. In a non-limiting example, mercury emissions are monitored once an hour to ensure compliance with government regulations. To illustrate, the Ontario Hydro method is used. In this known method, gases are collected for a pre-determined time, for example one hour. Mercury is precipitated from the collected gases, and the level is quantitated using a suitable method such as atomic absorption. Monitoring can also take more or less frequently than once an hour, depending on technical and commercial feasibility. Commercial continuous mercury monitors can be set to measure mercury and produce a number at a suitable frequency, for example once every 3-7 minutes. In various embodiments, the output of the mercury monitors is used to control the rate of addition of mercury sorbent. Depending on the results of monitoring, the rate of addition of the mercury sorbent is adjusted by either increasing the level of addition; decreasing it, or leaving it unchanged. To illustrate, if monitoring indicates mercury levels are higher than desired, the rate of addition of sorbent is increased until mercury levels return to a desired level. If mercury levels are at desired levels, the rate of sorbent addition can remain unchanged. Alternatively, the rate of sorbent addition can be lowered until monitoring indicates it should be increased to avoid high mercury levels. In this way, mercury emission reduction is achieved and excessive use of sorbent (with concomitant increase of ash) is avoided.
[0039] Mercury is monitored in the convective pathway at suitable locations. In various embodiments, mercury released into the atmosphere is monitored and measured on the clean side of the particulate control system. Mercury can also be monitored at a point in the convective pathway upstream of the particulate control system. Experiments show that as much as 20 to 30% of the mercury in coal is captured in the ash and not released into the atmosphere when no mercury sorbent is added. Addition of mercury sorbents according to the invention raises the amount of mercury capture (and thus reduces the amount of mercury emissions) to 90% or more.
[0040] Alternatively or in addition, a mercury sorbent composition is inserted or injected into the convective pathway of the coal burning facility to reduce the mercury levels. Preferably, the sorbent composition is added into a zone of the convective pathway downstream of the fireball (caused by combustion of the coal), which zone has a temperature above about 1500° F. and less than the fireball temperature of 2700-3000° F. In various embodiments, the temperature of sorbent is above about 1700° F. The zone preferably has a temperature below about 2700° F. In various embodiments, the injection zone has a temperature below 2600° F., below about 2500° F. or below about 2400° F. In non-limiting examples, the injection temperature is from 1700° F. to 2300° F., from 1700° F. to 2200° F., or from about 1500° F. to about 2200° F. As with pre-combustion addition, the sorbent can be in the form of a liquid or a solid (powder), and contains an effective level of a bromine or iodine compound. In various embodiments, the rate of addition of sorbent into the convective pathway is varied depending on the results of mercury monitoring as described above with respect to pre-combustion addition of sorbent.
[0041] In preferred embodiments, sorbent composition is added more or less continuously to the coal before combustion and/or to the convective pathway in the 1500° F.-2700° F. zone as described above. In various embodiments, automatic feedback loops are provided between the mercury monitoring apparatus and the sorbent feed apparatus. This allows for a constant monitoring of emitted mercury and adjustment of sorbent addition rates to control the process.
[0042] Along with the mercury sorbent, a sulfur sorbent is preferably added to control the release of sulfur into the environment. In various embodiments, the sulfur sorbent is added into the coal burning system at the same places the mercury sorbent is added. The sulfur sorbent can also be added at other places, depending on technical feasibility. In various embodiments, the components of the mercury sorbent and sulfur are combined into a single sorbent added to the coal or injected into the convective pathway. The sorbents, either separately or combined, are added in the form of a liquid or a solid. Solid compositions are usually in the form of a powder.
[0043] The sulfur sorbent preferably contains calcium at a level at least equal, on a molar basis, to the sulfur level present in the coal being burned. As a rule of thumb, the calcium level should be no more than about three times, on a molar basis, the level of sulfur. The 1:1 Ca:S level is preferred for efficient sulfur removal, and the upper 3:1 ratio is preferred to avoid production of excess ash from the combustion process. Treatment levels outside the preferred ranges are also part of the invention. Suitable sulfur sorbents are described, for example, in co-owned provisional application 60/583,420, filed Jun. 28, 2004, the disclosure of which is incorporated by reference.
[0044] Preferred sulfur sorbents include basic powders that contain calcium salts such as calcium oxide, hydroxide, and carbonate. Other basic powders containing calcium include portland cement, cement kiln dust, and lime kiln dust. In various embodiments, the sulfur sorbent also contains an aluminosilicate clay, montmorillonite, and/or kaolin. Preferably the sulfur sorbent contains suitable levels of silica and alumina (in a preferred embodiment, at least about 2% by weight of each) to form refractory materials with calcium sulfate formed by combustion of sulfur-containing coal. Silica and alumina can be added separately or as components of other materials such as Portland cement. In various embodiments, the sulfur sorbent also contains a suitable level of magnesium as MgO, contributed for example by dolomite or as a component of portland cement. In a non-limiting example, the sulfur sorbent contains 60-71% CaO, 12-15% SiO 2 , 4-18% Al 2 O 3 , 1-4% Fe 2 O 3 , 0.5-1.5% MgO, and 0.1-0.5% Na 2 O.
[0045] The mercury and sulfur sorbents can be added together or separately. For convenience, the components of the mercury and sulfur sorbents can be combined before addition onto the coal or injection into the convective pathways. In a preferred embodiment, the mercury sorbent contains calcium in addition to a source of halogen. In various embodiments, the mercury sorbent composition further comprises components that also reduce sulfur. The invention provides for addition of various sorbent compositions into the coal burning system to reduce emissions of mercury and, preferably, also of sulfur.
[0046] In various embodiments, sulfur and mercury sorbents are added separately. For example, a mercury sorbent is added to the coal pre-combustion and a sulfur sorbent is added post-combustion. Alternatively, a mercury sorbent is added post-combustion, while a sulfur sorbent is added pre-combustion. No matter the mode of addition, in a preferred embodiment the rate of addition of the various sorbents is adjusted as required on the basis of values of emitted sulfur and mercury determined by monitoring.
[0047] Mercury and sulfur sorbents are added at levels required to achieve the desired amount of reduced emissions. Preferred mercury reduction is 70% or more, preferably 80% or more and more preferable 90% or more, based on the total mercury in the coal being burned. On a weight basis, the mercury sorbent is generally added at a level of about 0.01 to 10% based on the weight of the coal. Preferred ranges include 0.05 to 5% and 0.1 to 1% by weight. The treat level varies depending on the content of halogen in the sorbent and the desired level of mercury emissions to be achieved. A level of 0.3% is suitable for many embodiments. In various embodiments, the initial treat level is adjusted up or down as required to achieve a desired emission level, based on monitoring as discussed above. The sorbent can be added in batch or continuously. In embodiments with continuous addition of sorbent, the treat levels are based on the feed rate of the coal being burned. Where the sorbent is added in batch, such as at the coal producer or at a separate mixing facility, the treat level is based on the weight of the coal being treated. In a preferred embodiment, the rate of addition or the treat level is adjusted based on a determination of emitted levels of mercury.
[0048] Likewise, sulfur sorbent is added at a level or rate satisfactory for reducing the level of emitted sulfur to an acceptable or desired level. In various embodiments, about 1 to 9% by weight of sulfur sorbent is added. The level or rate can be adjusted if desired based on the level of emitted sulfur determined by monitoring.
[0049] In preferred embodiments, mercury and sulfur are monitored using industry standard methods such as those published by the American Society for Testing and Materials (ASTM) or international standards published by the International Standards Organization (ISO). An apparatus comprising an analytical instrument is preferably disposed in the convective pathway downstream of the addition points of the mercury and sulfur sorbents. In a preferred embodiment, a mercury monitor is disposed on the clean side of the particulate control system. In various embodiments, a measured level of mercury or sulfur is used to provide feedback signals to pumps, solenoids, sprayers, and other devices that are actuated or controlled to adjust the rate of addition of a sorbent composition into the coal burning system. Alternatively or in addition, the rate of sorbent addition can be adjusted by a human operator based on the observed levels of mercury and/or sulfur.
[0050] To further illustrate, one embodiment of the present invention involves the addition of liquid mercury sorbent containing calcium bromide and water directly to raw or crushed coal prior to combustion. Addition of liquid mercury sorbent containing calcium bromide ranges from 0.1 to 5%, preferably from 0.025 to 2.5% on a wet basis, calculated assuming the calcium bromide is about 50% by weight of the sorbent. In a typical embodiment, approximately 1% of liquid sorbent containing 50% calcium bromide is added onto the coal prior to combustion.
[0051] In another embodiment, the invention involves the addition of calcium bromide solution both directly to the fuel and also in a zone of the furnace characterized by a temperature in the range of 2200° F. to 1500° F. In this embodiment, liquid mercury sorbent is added both before combustion and after combustion. Preferred treat levels of calcium bromide can be divided between the pre-combustion and post-combustion addition in any proportion.
[0052] In another embodiment, the invention provides for an addition of a calcium bromide solution such as discussed above, solely into the gaseous stream in a zone of the furnace characterized by a temperature in the range of 2200° F. to 1500° F.
[0053] The invention has been described above with respect to various preferred embodiments. Further non-limiting disclosure of the invention is provided in the Examples that follow. They illustrate the effectiveness of the invention when a liquid only and a liquid/solid sorbent system is applied for mercury remediation of fuels.
EXAMPLES
[0054] In the Examples, coals of varying BTU value, sulfur, and mercury content are burned in the CTF furnace at the Energy Environmental Research Center (EERC) at the University of North Dakota. Percent mercury and sulfur reductions are reported based on the total amount of the element in the coal prior to combustion.
Example 1
[0055] This example illustrates the mercury sorption ability of a calcium bromide/water solution when applied to a Powder River basin sub-bituminous coal. The as-fired coal has a moisture content of 2.408%, ash content of 4.83%, sulfur content of 0.29%, a heating value of 8,999 BTU and a mercury content of 0.122 μg/g. Combustion without sorbent results in a mercury concentration of 13.9 μg/m 3 in the exhaust gas. The fuel is ground to 70% passing 200 mesh and blended with 6% of a sorbent powder and 0.5% of a sorbent liquid, based on the weight of the coal. The powder contains by weight 40-45% Portland cement, 40-45% calcium oxide, and the remainder calcium or sodium montmorillonite. The liquid is a 50% by weight solution of calcium bromide in water.
[0056] The sorbents are mixed directly with the fuel for three minutes and then stored for combustion. The treated coal is fed to the furnace. Combustion results in a 90% mercury (total) removal at the bag house outlet and a 80% removal of sulfur as measured at the bag house outlet.
Example 2
[0057] This example illustrates the use of powder and liquid sorbents applied to three bituminous coals of varying mercury content. All coals are prepared as in Example #1, with the same addition levels of sorbents.
[0000]
% of Mercury
% Sulfur
Parameter
Coal
Removal
Removal
% Moisture
8.48
Pittsburgh,
97.97
40.0
% Sulfur
2.28
Seam, Bailey
Mercury
16.2 μg/m 3
Coal
BTU value
13,324
% Moisture
10.46
Freeman
97.9
36.0
% Sulfur
4.24
Crown III
Mercury
8.53 μg/m 3
BTU value
11,824
% Moisture
1.0
Kentucky
90.1
52.0
% Sulfur
1.25
Blend
Mercury
5.26 μg/m 3
BTU value
12,937
Example 3
[0058] This example illustrates addition of a mercury sorbent post-combustion. Pittsburgh Seam-Bailey Coal is ground to 70% passing 200 mesh. No sorbent was added to the fuel pre-combustion. Liquid sorbent containing 50% calcium bromide in water is duct injected into the gaseous stream of the furnace in the 2200° F.-1500° F. zone. The liquid sorbent is injected at the rate of approximately 1.5% by weight of the coal.
[0000]
Sorbent
% S
# Hg
Coal Type
Composition
reduction
Reduction
Pittsburgh Seam-
50% CaBr 2
28.13
96.0
Bailey Coal
50% H20
Example 4
[0059] This example illustrates addition of a liquid and a powder sorbent post-combustion. No sorbent was added directly to the fuel. Both fuels are bituminous and noted as Freeman Crown III and Pittsburgh Seam-Bailey Coal. In both cases the coal was ground to 70% minus 200 mesh prior to combustion. The powder and liquid sorbents are as used in Example 1. Rates of liquid and powder addition (percentages based on the weight of the coal being burned), as well as mercury and sulfur reduction levels, are presented in the table.
[0000]
Liquid
Powder
sorbent
sorbent
S
Hg
Coal Type
injection rate
injection rate
Reduction
Reduction
Freeman Crown III
1.0
4.0
36.27
97.89
Pittsburgh Seam-
1.5
6.10
33.90
96.00
Bailey Coal
Example 5
[0060] Pittsburgh Seam Bailey Coal is prepared as in Example 1. The powder sorbent of Example 1 is added to the coal pre-combustion at 9.5% by weight. The liquid sorbent of Example 1 (50% calcium bromide in water) is injected post-combustion in the 1500° F.-2200° F. zone at a rate of 0.77%, based on the burn rate of the coal. Sulfur reduction is 56.89% and mercury reduction is 93.67%.
Example 6
[0061] Kentucky Blend Coal is prepared as in Example 1. The powder sorbent of Example 1 is added to the coal pre-combustion at 6% by weight. The liquid sorbent of Example 1 (50% calcium bromide in water) is injected post-combustion in the 1500° F.-2200° F. zone at a rate of 2.63%, based on the burn rate of the coal. Sulfur reduction is 54.91% and mercury reduction is 93.0%.
[0062] Although the invention has been set forth above with an enabling description, it is to be understood that the invention is not limited to the disclosed embodiments. Variations and modifications that would occur to the person of skill in the art upon reading the description are also within the scope of the invention, which is defined in the appended claims.
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Sorbent compositions containing iodine are added to coal to mitigate the release of mercury and/or other harmful elements into the environment during combustion of coal containing natural levels of mercury.
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DESCRIPTION
Technical Field
This invention relates generally to folding or pocket knives, and more particularly to a folding knife unit which may be, for example, attached to wearing apparel such as a belt or similar accessory.
Background Art
Many persons find it desirable to have a small folding knife, commonly called a pocket knife, handy for their use. Men, for example, frequently carry a pocket knife in their trousers' pocket either loose or attached to the end of a chain. This knife must be moved to another pair of trousers whenever the individual changes his wearing apparel. For women, the knife is usually just carried loosely in their purse. As such, it frequently gravitates to the lower portion of the purse and sometimes is difficult to locate amid the other material carried therein. In either of these situations, it is sometimes found that the knife is not availabe whenever its use is desired.
Accordingly, it is one object of the present invention to provide a knife which is more readily available for use.
It is another object of the invention to provide a folding knife which may be releasibly attached to a rigid support base, the base being attachable to wearing apparel such as a belt.
It is a further object of the present invention to provide a folding knife which is securely held upon a base support but may be released therefrom with a minimum of manipulation.
Other objects and advantages of the invention will become apparent upon reading the detailed description and by reference to the drawings.
Disclosure of the Invention
In accordance with the invention a folding knife is releasibly attached to a rigid base plate. This base plate may then be attached to wearing apparel such as a belt, a purse strap or the like. The releasible attachment mechanism for the knife includes a stud projecting up from the base, which stud passes through an aperture in one side plate of the knife and frictionally engages the blade knife. A slight depression of the knife blade into its case brings about a disengagement of the stud with the blade and therefore permits the removal of the knife from the base plate.
Brief Description of the Drawings
FIG. 1 is a front view of the present invention shown as being attached to a belt or the like.
FIG. 2 is a front view of the base plate of the present invention.
FIG. 3 is a top view of the base plate shown in FIG. 2.
FIG. 4 is a longitudinal sectional drawing of the knife of FIG. 1.
FIG. 5 is a drawing illustrating another embodiment of the present invention.
Best Mode For Carrying Out The Invention
Referring to FIG. 1, the present invention is illustrated generally at 10. A folding knife 12 is releasibly attached to a base plate 14 which in turn is attached to wearing apparel such as a belt 16. The knife 12, of generally conventional construction, has a pair of side plates 18 (only one shown) and a blade 20. The blade 20 pivots about blade pivot 22 in a normal manner. The means for attachment of the knife 12 to the base plate 14, although described in more detail hereinafter, involves the use of a headed stud 24 and a cylindrical stud 26.
Referring now to FIGS. 2 and 3, details of the base plate 14 are illustrated. As may be seen, the base plate 14 is essentially planar with the studs 24 and 26 projecting essentially vertically from a front face 15. The stud 24 has a shaft 28 of reduced diameter for purposes discussed hereinafter. Stud 26 has an annular recess of reduced diameter at 30, and having a width at least equal to the thickness of the blade 20, also whose purpose is described hereinafter. Preferrably the end 31 of the stud 26 is tapered as shown in FIG. 3. The rear surface 17 of the base plate 14, when used as a belt buckle or the like, is provided with appropriate apparel attachment means. This includes a loop 32 attached with hinged means 34 to the rear surface 17 of the base plate 14. Also, projecting from the rear surface 17 of the base plate 14 is a hook or prong 36 for engagement with apertures in a typical belt thereby permitting adjustments of the effective length of the belt in a manner similar to that known in the art.
The principle of operation of the present invention may be understood by referring to FIG. 4 when taken into combination with FIG. 1. This drawing is a sectional view of the knife 12 having the upper or front side plate 18 removed. Accordingly the rear side plate 38 may be seen. Also this permits the back spring 40 to be seen with its attachment rivets 42, 44. As illustrated above, the knife blade 20 is attached to the side plates 18 and 38 with a pivot 22. The area of the blade 20 surrounding this pivot comprises a conventional blade tang 46 and tang offset 48 that bears against the aforementioned back spring 40. The blade 20 is provided with aperture 50 having a diameter slightly in excess of the stud 26. Shown in phantom lines is an aperture 52 in the side plate 38 having a similar dimension to that of aperture 50. It may be seen that if the blade 20 is depressed toward the back spring 40, apertures 50 and 52 may be aligned to accept the aforementioned stud 26 therethrough. The apertures 50, 52 are only slightly misaligned when the blade is received between the side plates 18, 36. If the amount of displacement is less than one-half the diameter, the tapered end of the stud 26 can be pushed through both apertures to bring them into alignment. Thereafter, upon releasing pressure on the blade 20, the apertures 50, 52 tend to become displaced thereby causing the aperture 50 on the blade 20 to frictionally engage the recess 30 of the stud 26. The side plate 38 is provided with a notch 54 at an end near the blade pivot 22. Although less convenient, the notch 54 can be in the opposite end of the side plate 38. This notch 54 is provided to engage the aforementioned shaft 28 of stud 24. The spacing between the notch 54 and the apertures 50, 52, corresponds to the dimension between the stud 24 and the stud 26 shown in the figures. The lateral orientation of studs 24, 26 is chosen to artistically display the knife 12 on the base plate 14. Thus, they can be angularly oriented as shown, or they can be vertically or horizontally oriented.
From the foregoing description, the manner of attachment of the knife 12 to the back plate 14 may be ascertained. More specifically, this attachment includes placing the notch 54 of the side plate 38 against the shaft 28 of stud 24. Thereafter, the stud 26 may be received in aperture 52 of the side plate 38 and, upon depression of the blade 20 toward the back spring 40, the aperture 50 also accepts the stud 26. When the blade 20 is released, the aperture 50 engages the recess 30 of the stud 26 whereupon the knife 12 is securely attached to the base plate 14. Release of the knife 12 is accomplished in a reverse manner; that is, a slight depression of the blade 20 toward the back spring 40 permits the apertures 50 and 52 to be disengaged from stud 26. Thereafter notch 54 can be disengaged from the shaft 28 and the knife may be used in a normal manner.
A knife 12 having a single blade 20 is shown in the above-referenced drawings. The present invention however is not limited to a single bladed knife. A knife with additional blades hinged at the same end as blade 20, or at the opposite end of the knife, may similarly be attached to a base plate. The only limitation is that the blade closest to the base plate would be provided with the afore-mentioned aperture 50. Normally this will be the largest blade of the knife in order that the upper edge thereof is accessible for the application of a depressing force. (All blades could be provided with apertures to receive the stud 26; however, this would be inconvenient in engagement with or release from the stud.) Further, the knife may have other constructions similar to those of U.S. Pat. Nos. 4,161,818, 4,218,819 and U.S. patent application Ser. No. 346,725, filed Feb. 8, 1982.
As stated above, the construction illustrated in FIGS. 1-3 is intended for use on a belt buckle. It will be understood that appropriate construction may be added to the rear surface 17 of the base plate 14 to accomplish attachment to other articles of wearing apparel. This may include the strap attachment of a woman's purse, to the surface of the purse itself, to a pocket clip, tie clip, etc. In all of the embodiments, the structure on the face 15 of the base plate 14 for the reception of the knife 12 and the appropriate engagement means on the knife would be substantially identical.
A horizontal orientation of a knife on a base plate, as referred to previously, is illustrated in FIG. 5. Also illustrated therein is another embodiment of means for releasible attachment of the folding knife to the base plate. In this embodiment, the base plate 14' is provided with a generally U-shaped clip 56. This clip 56 is sized to frictionally grasp the side plate of the knife 12 closest to the base plate 14'. The base plate 14' is provided with the same upright stud 26 as shown in the previous embodiment, and this stud (with annular recess 30) engages the blade of the knife in the same manner as previously described. It will be understood that the base plate 14' can be provided for attachment to wearing apparel, if desired.
From the foregoing it will be recognized that a convenient folding knife construction is provided which will make the knife readily accessible when its use is desired. If applied to a belt buckle, a person would normally be changing belts between different pairs of trousers and thus the knife would be automatically changed to the new pair of trousers. In a similar fashion, the knife attached to the strap of a woman's purse would be readily accessible and more convenient for use.
The feature of attachment to wearing apparel, although a particular advantage of the embodiments described above, is not a limitation to the present invention. Accordingly, the combination of a base and a releasible folding knife is the essential thrust of the present invention.
It is, of course, understood that although a preferred embodiment of the present invention has been illustrated and described, various modification thereof will become apparent to those skilled in the art. Accordingly, the scope of the invention should be defined only by the appended claims and the equivalence thereof.
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A folding knife unit particularly for the attachment to wearing apparel. A base plate of the unit can be provided with elements for securing the base plate to the apparel, these elements usually being on the rear surface of the base plate. The front surface of the base or base plate is provided with a headed stud in one embodiment to engage a notch in one end of the folding knife, and a second stud to pass through an aperture in one side plate of the knife and an aligned aperture in the closest knife blade. The second stud is provided with an annular recess, and the action of the backspring causes the knife blade to releasibly engage that recess whereby the knife is releasibly secured to the base plate. In another embodiment, a spring clip engages one end of a side plate rather than the headed stud.
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RELATED APPLICATIONS
[0001] This is the national stage under 35 USC 371 of international application PCT/EP2014/063097, filed on Jun. 23, 2014, which claims the benefit of the Jul. 2, 2013 priority date of German application DE 102013106926.6, the contents of which are herein incorporated by reference.
FIELD OF INVENTION
[0002] The invention relates to the transport of containers, and in particular, to detecting the fill level of a transport section for transporting containers.
BACKGROUND
[0003] A typical conveyor carries containers from one machine to another. In most cases, it is desirable for the conveyor to maintain a steady flow rate, measured in containers per unit time. This is easy to do if containers are fed into the conveyor and taken from the conveyor at a constant rate. Unfortunately, it is not possible to guarantee that this is the case. As a result, there are often fluctuations in these quantities. These in turn interfere with maintaining a steady flow rate.
[0004] A failure to maintain a steady flow rate can have undesirable consequences. For one thing, containers can collide with each other. This creates noise and raises the risk of containers falling over. In addition, containers can exert forces on their neighbors. This leads to wear on the containers, and sometimes to damage of container decorations, such as labels.
[0005] A known way to maintain a steady flow rate is to measure the fill level of the conveyor and to adjust the conveyor speed adaptively in response to the measured fill level.
[0006] In known conveyors, one or more switches detect a fill level of a particular transport section at a transport area that is occupied by a tightly packed stream of containers. However the use of switches necessarily results in quantized measurements, with the quantization error corresponding to the number of switches.
SUMMARY
[0007] An object of the invention is to continuously and accurately measure fill level of a conveyor or of a transport section so that a conveyor speed can be more effectively controlled.
[0008] The invention promotes the ability to know the fill level of the conveyor or transport section thereof at any time, and the distribution of containers being transported on the conveyor. This permits the transport speed of the conveyor or a transport section thereof to be adapted at any time so as to maintain an optimal output of a machine upstream or downstream of the conveyor. The invention also promotes the gentle transport of containers with reduced noise emission, optimum buffering, and increased productivity.
[0009] Embodiments of the invention include those that change the multi-row tightly packed stream of transport containers by changing the transport direction, those that do so by changing the transport speed, those that do so tilting the transport plane crosswise to the transport direction, and those that carry out any combination of the foregoing.
[0010] Embodiments also include those that determine a fill level f as a ratio between two widths: a width of the entire conveyor and a width of the unused portion of the conveyor. For example, in one embodiment, this is defined by f=(B−x)/B where x is measured and B is an overall width of the transport section. Among these embodiments are those that control transport speed of a transport section based on this determined fill level f.
[0011] Also among the embodiments are those that control transport speed of a transport section in an effort to achieve a nominal output Q of a machine following the transport section and/or of a machine that precedes the transport section.
[0012] Additional embodiments include one or more sensors that determine a transport speed of a transport section or a portion thereof. In some embodiments, these sensors collectively form a sensor unit.
[0013] Yet other embodiments periodically derive a control variable that is proportional to the continuously determined fill level. Among the embodiments that derive a control variable are those that derive it by taking into account a transport length between the measuring position and the outlet side of the transport section, those that derive it based on a mean value of fill level, and those that derive it based on any combination of the foregoing. In either case, the control variable is derived in an effort to achieve optimum control of the transport speed of the conveyor or of a transport section thereof.
[0014] Embodiments further include those that save the continuously detected fill level in a memory of a controller, a suitable memory being, for example, a shift register thereof.
[0015] In some embodiments, a transport section forms an outlet of the conveyor.
[0016] Yet other embodiments cause at least two diversions of the transport direction before the containers arrive at a section at which the fill level is determined. Among these are embodiments that divert a multi-row stream of containers twice. Such embodiments divert the stream on a first transport section moving in a first transport direction so that it flows in a second transport direction on a second transport section, and then divert the stream again so that it flows in a third transport direction on a third transport section. In these embodiments, a measuring section follows the second diversion. This is where a distance sensor measures the fill level.
[0017] Additional embodiments include those that have any combination of one or more of the foregoing features.
[0018] In one aspect, the invention features a method for continuously detecting a fill level of a conveyor for transporting containers on a transport plane, the conveyor having a first transport section that extends in a first transport direction, the first transport section having a measuring section having first and second sides and a width between the first and second sides. The method includes forming a container stream along the first transport section, forming a container knot at the measuring section, the container knot including a tightly packed multi-row stream of containers, using a first contactless distance sensor, measuring a distance from a first side of the measuring section to the container knot, and based on the measured distance, determining a fill level of the conveyor.
[0019] The formation of a container knot can be achieved in several ways. Among these are causing a transport speed of the first transport section to differ from a transport speed of a second transport section that precedes the first transport section, diverting containers from a second transport direction to the first transport direction, tilting a transport plane along which the containers are transported, wherein tilting includes tilting in a direction crosswise to the first transport direction, or any combination of the foregoing.
[0020] Practices of the invention include those in which determining a fill level includes determining a ratio between the width and a distance between the first side and the container knot.
[0021] Other practices of the invention include including controlling a transport speed of at least a portion of the conveyor based at least in part on the fill level. Among these are practices that include controlling the transport speed at least based at least in part on nominal flow rate of a container-processing machine connected to the conveyor. Such a container-processing machine can be connected upstream from the conveyor, in which case the containers are provided to the conveyor, resulting a positive value of flow rate. Or the container-processing machine can be connected downstream of the conveyor, in which case containers are removed from the conveyor, thus resulting in a negative flow rate.
[0022] Practices of the invention include those in which measuring a distance includes using a second contactless distance sensor to measure the distance.
[0023] Other practices of the invention include deriving a control variable based at least in part on the fill level. Among these practices are those in which deriving the control variable includes deriving the control variable based at least in part on a distance between the measuring position and an outlet of the conveyor, and those in which deriving the control variable includes deriving the control value at least in part based on a mean fill value that has been evaluated based on fill values stored in memory.
[0024] In some practices, the first transport section forms an outlet of the conveyor.
[0025] In some practices of the invention, forming a container stream along the first transport section includes, prior to the measuring section, causing first and second diversions of the container stream. In these practices, the first diversion diverts the container stream from a second transport direction to a third transport direction, and the second diversion diverts the container stream from the second transport direction to the first transport direction.
[0026] In other practices, forming the container stream along the first transport section includes receiving a multi-row container stream from an inlet of the conveyor, transporting the container stream along a second transport section along a second transport direction to a third transport section, transporting the container stream along the third transport section in a third transport direction, and passing the container stream from the third transport section to the first transport section prior to the measuring section.
[0027] The use of ordinal adjectives in the claims and summary does not necessarily match the corresponding use of ordinal adjectives in the detailed description. As an example, the first transport section in the claims and summary corresponds to the third transport section in the detailed description. This mismatch arises solely because the order in which components are introduced in the claims does not match the order in which they are introduced in the description.
[0028] As used herein, “containers” include cans or bottles, whether made of metal and/or plastic.
[0029] As used herein, a “tightly packed multi-row stream of containers” refers to a stream of transport containers in which the containers are adjacent to each other or lie against each other in the transport direction and crosswise to it and in which a force urges the containers against each other so that they are tightly packed.
[0030] As used herein, “container knot” refers to a cluster of containers that tends to form in the wake of a diversion in container flow and in response to the turbulence introduced by such a diversion.
[0031] As used herein, terms such as “substantially” and “approximately” refer to deviations from an exact value by ±10%, preferably by ±5%, and/or deviations in the form of changes that are not significant for function.
[0032] Further developments, benefits, and application possibilities of the invention arise also from the following description of examples of embodiments and from the figures. Moreover, all characteristics described and/or illustrated individually or in any combination are categorically the subject of the invention, regardless of their inclusion in the claims or reference to them. The content of the claims is also an integral part of the description.
BRIEF DESCRIPTION OF THE DRAWING
[0033] The invention is explained in more detail below by means of the figure, which shows a plan view of a conveyor for transporting containers.
DETAILED DESCRIPTION
[0034] The sole figure shows a conveyor 1 having an inlet side 1 . 1 and an outlet side 1 . 2 between which extend first, second, and third consecutive transport sections 3 , 4 , 5 . The first transport section 3 forms the inlet side 1 . 1 of the conveyor 1 and transports containers in a first transport direction A at a first transport speed V 3 . The third transport section 5 forms the outlet side 1 . 2 and transports containers toward the outlet side 1 . 2 in a third transport direction C at a third transport speed V 5 . The second transport section 4 transports containers in a second transport direction B and connects the first transport section 3 to the third transport section 5 .
[0035] In the illustrated embodiment, a set of first conveyor belts 3 . 1 forms the first transport section 3 . These first conveyor belts 3 . 1 are preferably hinged belt chains placed side-by-side adjacent to each other along a direction perpendicular to the first transport direction A. A first drive 6 endlessly circulates the first conveyor belts 3 . 1 so that they move at the first transport speed V 3 .
[0036] Similarly, a set of second conveyor belts 5 . 1 forms the third transport section 5 . Like the first conveyor belts 3 . 1 , the second conveyor belts 5 . 1 are preferably hinged belt chains placed side-by-side adjacent to each other along a direction perpendicular to the third transport direction C. A second drive 7 endlessly circulates the second conveyor belts 5 . 1 so that they move at a third transport speed V 5 .
[0037] In the illustrated embodiment, the second transport section 4 transfers containers between the first transport section 3 and the third transport section 5 . It does so in part by sharing the first conveyor belts 3 . 1 and the second conveyor belts 5 . 1 . This is achieved by placing part of the third transport section 5 adjacent to part of the first transport section 3 .
[0038] Although the first, second, and third transport directions A, B, C are the desired transport directions of the first, second, and third transport sections 3 , 4 , 5 , individual containers 2 on these transport sections can temporarily move in a transport direction having a component that is perpendicular to the desired transport direction. This might occur, for example, as a result of containers 2 pushing against other containers from behind or from the side.
[0039] The first and second conveyor belts 3 . 1 , 5 . 1 are arranged to form a horizontal or substantially horizontal transport plane or, in some cases, a transport plane that is slightly inclined relative to the horizontal On this transport plane, containers 2 stand upright on their respective bases. The first and second drives 6 , 7 are located where the first and second conveyor belts 3 . 1 , 5 . 1 reverse direction.
[0040] First and second external guide rails 8 , 9 extend along the first, second, and third transport sections 3 , 4 , 5 . These first and second guide rails 8 , 9 thus follow the first, second, and third conveying directions A, B, C.
[0041] Within the second transport section 4 , the second guide rail 9 forms a diverting section 9 . 1 that extends between the end of the first transport section 3 and the beginning of the third transport section 5 . This diverting section 9 . 1 diverts a container stream moved by the first transport section 3 along the first transport direction A so that it moves in the second transport direction B, which runs at an angle relative to the first transport direction A. This results in a first diversion.
[0042] At the end of the second transport section 4 , where the second transport section meets the third transport section 5 , the container stream experiences a second diversion.
[0043] As a result of this second diversion, the containers become rearranged in a way that forms a container knot 11 in which the containers are tightly packed adjacent to each other in multiple rows, with each row parallel to the third transport direction C. A first one of these rows is closest to the second guide rail 9 . A second one of these rows is adjacent to this first row but further from the second guide rail 9 . Subsequent rows are adjacent to preceding rows and extend further in a direction perpendicular to the transport direction C, with each subsequent row being further from the second guide rail 9 and closer to the first guide rail 8 . The exact arrangement of containers within the container knot 11 depends on the relationship between the first transport speed V 3 and the third transport speed V 5 , as well as on a certain tilt of the transport plane crosswise to the transport direction.
[0044] The third transport section 5 includes a measuring section 12 immediately after the junction between the second and third transport sections 4 , 5 where the container knot 11 tends to form. The measuring section includes a first distance sensor 13 arranged on a side of the third transport section 5 either on the first or second guide rail 8 , 9 . Suitable types of first distance sensor 13 are non-contacting sensors. These include ultrasound sensors or optical sensors, such as an infrared sensors. Some embodiments feature a second distance sensor 16 . In these embodiments, the first and second distance sensors 13 , 16 form a unit.
[0045] As the conveyor 1 operates, the first distance sensor 13 constantly measures a distance x to the container knot 11 on the measuring section 12 or on the feed side of the third transport section 5 and provides this distance to a controller 14 . Based on this measured distance x and a known width B of the third transport section 5 in a direction perpendicular to its conveying direction C, which corresponds to the distance between the first and second guide rails 8 , 9 , the controller 14 continuously determine a fill level f of the third transport section 5 . In one embodiment, it does so by evaluating a ratio between the width B of the third transport section 5 and the extent of the unused portion B-x of the transport section 5 . A suitable formula relied upon by the controller 14 is
[0000] f =( B−x )/ B.
[0000] Of course, there are many equivalent ways to express fill level in a way that provides a basis for control. For example, a reciprocal of the above can be used, or the above formula can be scaled by a constant. Or, for special purposes, a non-linear measure may be used. It is apparent from inspection that when the transport section 5 is completely filled, then x will be zero, which means f will become unity, and when the transport section 5 is completely empty, then x will be equal to the width B, in which case f will become zero, thus indicating an empty transport section 5 . It is also of interest to note that f is a continuous variable and that the sizes of the containers are irrelevant. In fact, the above method will work even if the containers are not all the same size.
[0046] This continuously determined fill level f provides the controller 14 with a basis for controlling the overall transport speed of the conveyor 1 , and in particular, for controlling the third transport speed V 5 by corresponding control of the second drive 7 . This permits the controller 14 to achieve a nominal output Q of a container processing machine 15 that follows the outlet side 1 . 2 . The nominal output Q is given by a number of containers 2 that the container processing machine 15 can process processed per unit of time, for example per hour, in normal operation.
[0047] In one embodiment, the controller 14 causes the third transport speed V 5 to be given by:
[0000] V 5=( Q*d 2 *3 1/2 )/( f*B* 2)
[0000] where d is the diameter of a container 2 . In the case where containers are not cylindrical, as a result of which the container's diameter is not constant and may vary as a function of a coordinate along the container's vertical axis, d represents a maximum diameter. In cases where containers do not have a circular cross-section, d represents a maximum lineal dimension.
[0048] In some embodiments, the continuously detected fill level f and the transport length between the measuring section 12 and the outlet side 1 . 2 can be used to derive a control variable F that is a function of the fill level f to control the third transport speed V 5 depending on the nominal output Q:
[0000] V 5=( Q*d 2 *3 1/2 )/( F*B* 2)
[0049] In this embodiment, the controller 14 saves the continuously detected fill level f in a memory, for example in its shift register. At specified time intervals, the controller 14 derives the control variable F from the current value of the detected fill level f stored in memory. In some embodiments, the controller 14 averages previous values of the fill level f to derive the control variable F. This results in smoother control. Such embodiments effectively implement a low-pass filtering mechanism.
[0050] The continuous detection of the fill level f makes it possible to control the transport speed of the conveyor 1 so that the containers 2 arrive at the container processing machine 15 at an optimal rate without any interruption or blockages in the container stream.
[0051] In alternative embodiments, other diverting structures can replace the diagonally running diverter 9 . 1 shown in the figure. An example of such a diverter is a set of one or more baffle plates.
[0052] Regardless of such modifications and variations, it is common to all embodiments that, by changing any combination of transport direction, transport speed, and transport-plane tilt on a measuring section of the transport section, one can create a container knot 11 that immediately follows one side of the transport section. This side extends in the transport direction. Using at least one contactless distance sensor, it becomes possible to measure the distance x to the container knot 11 and to use that distance as a basis for controlling conveyor speed.
[0053] Having described the invention, and a preferred embodiment thereof, what we claim as new, and secured by letters patent is:
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A method for continuously detecting a fill level of a conveyor for transporting containers on a transport plane includes forming a container stream along said first transport section of the conveyor, forming a container knot at a measuring section, the container knot comprising a tightly packed multi-row stream of containers, using a first contactless distance sensor, measuring a distance from a first side of the measuring section to the container knot, and, based on the measured distance, determining a fill level of the conveyor.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application constitutes the National Stage Entry of the PCT International Patent Application No. PCT/EP2004/014632, filed Dec. 22, 2004, and claims the priority of German Patent Application No. 10 2004 004 098.2, filed Jan. 27, 2004, in the German Patent and Trademark Office, the disclosures of which are incorporated herein by reference.
[0002] 1. Field of the Invention
[0003] An aspect of the present invention relates to a method of evaluating a scattered light signal generated by a scattered light receiver when detecting especially fine particles in a carrier medium.
[0004] Another aspect of the present invention relates to a scattered light detector to carry out the above-cited method having a housing, an inlet opening and an outlet opening in said housing, between which the carrier medium flows through the housing on a flow path, having a light source which directs light to a scattered light center lying on the flow path, having a scattered light receiver to receive a portion of the light scattered on particles in the scattered light center, and having a scattered light signal amplifier to amplify the scattered light signal.
[0005] 2. Description of the Related Art
[0006] Methods and devices for evaluating a scattered light signal are known and used especially in scattered light detectors for aspiration fire alarm systems. Generally, they detect solid matter or liquid particles, whereby the carrier medium includes a representative partial quantity of the air of a room to be monitored or the device cooling air of a device to be monitored. In the case of an aspiration fire alarm system, this representative quantity of air is actively suctioned by means of a ventilator and fed into the inlet opening of the scattered light detector. In the case of monitored devices such as EDP equipment, for example, or other similar electronic devices such as measuring, control or regulating devices, it is, in principle, also possible to use the internal flow of the device-cooling air itself to feed a representative partial quantity of the device-cooling air into the inlet opening of the scattered light detector as the carrier medium. In this case, an active suctioning ventilator is then rendered unnecessary.
[0007] A description of the operation of scattered light detectors as described above will now be provided. While the carrier medium flows through the scattered light center on a flow path thereof through the housing of the scattered light detector, the light of the light source traverses the scattered light center, and, thus, the carrier medium flowing through it and, provided it is not scattered onto particles in the carrier medium, is absorbed in a light trap opposite thereto. This is the normal and predominantly prevailing operational state. When the ray of light from the light source hits a particle, for example a smoke particle or a smoke aerosol, providing a first indication of a fire in the initial stages, this particle deflects a fraction of the light from its original direction as scattered light. This scattered light is then received by a highly photosensitive receiver, the so-called scattered light receiver, and its intensity is measured by a subsequent evaluation circuit. An alarm is triggered when a specific light intensity threshold is exceeded.
[0008] A precise adaptation to environmental variables, special design features, and appropriate signal processing are necessary so that such an optical system works accurately and with high sensitivity. This would entail, for example, changing the sensitivity of the detector based on the scattered light receiver's point of installation. For instance, detector sensitivity needs to be set far higher for clean rooms, in which, for example, computer chips are manufactured, than it does in offices spaces, as even the smallest quantities of dust particles or suspended particles in the air of the former needs to trigger an alarm.
[0009] Since the intensity of the light radiated by the detector's light source stands in direct correlation to the temperature, it is likewise necessary to configure temperature monitoring for the detector. It is in fact theoretically necessary, given a rising temperature, to increase the light output of the light source, for example by increasing the operational current. Apart from the high energy costs, however, this leads to a disproportionately shortened operating life, especially in the case of laser diodes. Even if the maximum operational current of an LED is not reached, operation at the maximum upper current limit shortens its lifetime immensely. Generally speaking, configuring a highly-sensitive optical scattered light detector requires precise and adapted signal processing.
[0010] Printed publication EP 0 733 894 B1, which relates to adapting the temperature of a photoelectric sensor for detecting fine particles in the air such as, for example, smoke or dust, is provided to this end. The detector disclosed in this publication has a light source and a light-receiver, which produces a sensor output upon detecting a scattering of light that is caused by the presence of fine particles in the light radiated from the light source. The detector thereby includes a controller that controls the quantity of light emitted from the light source based on a reference temperature value. The light source is thereby pulsed switched. If its temperature exceeds a specific threshold, the controller changes the interval between the individual light pulses. This enables an intensified cooling of the light source. This control loop is continued until the highest threshold is exceeded, upon which an alarm signal is then triggered, since the cause can be attributed to either a malfunctioning of the detector or the rise in temperature being due to the rise in the ambient temperature in consequence of a fire.
[0011] The disadvantage to this device, however, is that increasing the distance between the respective light pulses increases the detector's dead area, at the expense of accuracy. While this device essentially solves the problem of dependency between temperature and light output of the light source, it indicates no possibility of counteracting the change in detector sensitivity, of calibrating the detector, or evaluating the received scattered light signal according to given specifications.
[0012] Calibrating a conventional scattered light detector is customarily done with a reference signal. To properly design, test or demonstrate fire alarm systems, it is known to conduct smoke tests using a procedure which produces smoke aerosols, wherein a test sample is pyrolized by heating. Among other things, these tests thereby serve in determining where the detectors should be arranged within an electronic system or within a room. In order to make a test as realistic as possible, methods for producing smoke aerosols are used, with the help of which a reference value can be created for the smoke in order to test and/or calibrate the smoke detectors to same.
[0013] The German DE 4 329 847 C1 printed patent describes a method for producing smoke aerosols to properly design, test or demonstrate the effectiveness of fire alarm systems as well as a pyrolysis device with which this method may be carried out. In the procedure, a test sample, for example an electrical cable or other such similar object, is kept at a constant or virtually constant temperature for a defined interval of time. The device and this associated method thereby work in the so-called pyrolysis phase, in which low-power and invisible smoke aerosols are released. The detection range of modern early warning fire systems lies within this first phase of a developing fire. Depending upon the requirements for detection accuracy, it must also be possible, among other things, to then adapt the scattered light detector to this reference signal.
SUMMARY OF THE INVENTION
[0014] Based on the points specified above, the present invention addresses the task of further developing a method for evaluating a scattered light signal to be more effective, more versatile and more exact. The invention furthermore addresses the task of providing a scattered light detector to carry out the above-cited method, its mode of functioning being more precise, more versatile, less prone to errors and less expensive than that of the scattered light detectors known in the art.
[0015] Therefore, in accordance with an aspect of the invention, a method of evaluating a scattered light signal generated by a scattered light receiver when detecting especially fine particles in a carrier medium, comprising running the scattered light signal through a filter algorithm operation to evaluate the scattered light signal subject to specific filter algorithms, the filter algorithm operation being based on a slope of the scattered light signal.
[0016] Another aspect of the invention is that cycling through various calibrating and compensating operations enables an exact adjustment of the scattered light signal. Depending upon the requirements of the scattered light signal detection, the accuracy and the prevailing environment variables, it is therefore possible to adapt the scattered light detector in such a manner so as to enable a precise and error-free scattered light detection.
[0017] In each individual operation, adjustments are made. In a calibration operation, the scattered light detector is calibrated with a reference signal. Among other factors, this adjustment takes the respective environmental conditions into account since a carrier medium can exhibit a different “base level of pollution” in normal operation depending upon site of installation.
[0018] In a drift compensation operation, the above-cited calibration is made over a longer period of time, i.e. usually 2 to 3 days. Averaging the chamber value to a tracked chamber value, whereby the chamber value is the scattered light signal to be received by the scattered light detector when there is no smoke or smoke aerosol present in the scattered light center, thereby improves the accuracy of the scattered light detector, since its sensitivity adjustment can be made with due consideration of this average value.
[0019] A temperature compensation operation serves in adapting the scattered light detector to the dependent temperature/radiated light output relationship. Allowance is made here for the fact that actual light output emitted by a source of light decreases as temperature increases and vice-versa.
[0020] A sensitivity adjusting operation enables the scattered light detector to be adjusted to the necessary stages of sensitivity, as required depending upon detector area of application.
[0021] A filter algorithm operation enables the analysis of a scattered light signal subject to specific filter algorithms in order to ensure reliable and accurate alarm output.
[0022] A combination of different adapting and calibrating operations results in a detection method which is extremely precise, of versatile applicability and which additionally functions exceptionally accurate. Of course, in order to save costs, it would be conceivable to omit one or the other adapting operations, provided same would not be expressly necessary.
[0023] A method for evaluating a scattered light signal wherein the scattered light detector has an integration amplifier as the scattered light signal amplifier, in which the integration time of the integration amplifier is set during the calibration operation such that the scattered light signal corresponds to a reference signal of a reference indicator, constitutes an advantageous improvement with the method specified at the outset. Changing the integration time enables a very economical and readily automated adaptation of the scattered light detector to a reference signal. Among other things, it is also possible to make this adaptation by adjusting the drive current of the light source so as to change the radiated luminous energy which, however, occurs at the expense of the operating life of the light source and requires increased power. With the method according to the invention, the drive current of the light source remains constant.
[0024] Different methods can be used to change the sensitivity of a scattered light detector in accordance with the invention. One would be changing the pulse width of the light source drive current. The pulse width refers to the duration of a light pulse. Reducing the pulse width decreases the sensitivity of the scattered light detector, increasing the pulse width raises the sensitivity. The other possibility is changing the integration time of any integration amplifier provided to function as a scattered light signal amplifier. With this method as well, increasing the integration time of the integration amplifier leads to higher sensitivity and reducing the integration time leads to a scattered light detector with less responsiveness. Both methods of changing the sensitivity of a scattered light detector are economical, forestall material damage and allow scattered light detectors to be adapted in an exemplarily simple manner. It is of course possible to change both the integration time as well as the pulse width incrementally or continuously. Incremental here refers to, for example, fixed increments of percentile sensitivities such that the scattered light detector works at 25%, 50%, 75% and 100% sensitivity. Setting these sensitivity stages is done with switching means, e.g. a DIL switch. It is of course also possible to adjust sensitivity using a communication interface, for example by means of a PC or that of a network. This then allows the adjusting of a scattered light detector, an entire fire alarm system respectively, by means of just one control center.
[0025] Whether the method allows an incremental or a continuous adjustment of the integration time or the pulse width is a function of the monitoring system's boundary conditions. In order to ensure particularly effective and sensitive monitoring, as is necessary for example in clean rooms, scattered light detectors must issue a detection signal at the presence of even the smallest particle quantities in the air, which hence requires a very fine sensitivity adjustment. Besides conventional switches or communication interfaces for PCs or networks, sensitivity adjustments can, of course, also be made wirelessly.
[0026] The relationship between temperature and light source emission has already been described in detail above. In the temperature compensation operation, a temperature sensor arranged in the flow path of the carrier medium is hence used for the temperature compensation of the scattered light signal. This means that the temperature of the carrier medium and/or the environment is determined continuously or in pulses in order to be able to adapt the light source which emits light in the scattered light detector. Thus, should a rise in temperature to the carrier medium in the flow path be determined, a direct adjustment of the light source can be made in order to ensure a constant light emission. This temperature compensation is advantageously made by changing the pulse width of the drive current of the light source associated with the scattered light receiver. That means that with a rise in temperature of the carrier medium as detected by the temperature sensor, the pulse width of the light source's drive current is reduced, in consequence of which there is a lesser heating of the light source and thus also the carrier medium. If, instead, a decrease in temperature is determined, the pulse width of the light source's drive current can be increased, which entails a rise in temperature. Yet in all cases, the light source's drive current remains constant.
[0027] It is advantageous to filter the scattered light signal differently depending on its slope prior to comparison with preset threshold values, in particular alarm thresholds. In this way, deceptive values can be recognized, eliminated and a false alarm prevented, since only the presence of actual alarm values; i.e. values which are above a given threshold, will lead to an alarm output signal. The amount of time over which the scattered light signal exceeds a threshold value, in particular an alarm threshold, for example, is taken into consideration when doing so. Only once a fixed time interval is reached will an alarm signal then be emitted. The lowpass filtering of the input signal as soon as its slope exceeds a pre-defined threshold furthermore results in a scattered light detector device which has a very good signal-to-noise-ratio, since short, rapid deflections in the input signal, as frequently caused by air pollutants, i.e., small quantities of dust particles in the air flow to be monitored, are not recognized as alarm values.
[0028] A further possibility to attain an improved detection algorithm and fewer false alarms with a scattered light detector is to generate a tracked chamber value. This tracked chamber value is averaged from the chamber value of the scattered light detector over a longer period of time and is carried out during the drift compensation operation. The chamber value is the scattered light signal which results when no smoke is present in the scattered light center of the scattered light detector. This scattered light signal is thereby formed from both the detector's own reflection surfaces as well as due to pollutants in the air. Averaging this chamber value in the drift compensation operation over several days (i.e., 2 to 3 days), thus results in a very exact device calibration. This averaged tracked chamber value can be subtracted from the scattered light signal's operating conditions. One is left with a scattered light signal free of errors due to air pollutants, environmental conditions or a detector's own reflectance, etc.
[0029] To carry out the above-specified and/or other processing operations, a scattered light detector is presented, the scattered light detector comprising a housing, an inlet opening and an outlet opening in the housing, between which the carrier medium flows along a flow path, a light source, which directs light to a scattered light center lying on the flow path, a scattered light receiver to receive a portion of the light scattered on particles in the scattered light center, and a scattered light signal amplifier to amplify the scattered light signal, the scattered light signal amplifier being configured as an integration amplifier, wherein a filter algorithm operation is provided to filter the scattered light signal based on a slope thereof.
[0030] In order to adjust the scattered light receiver's sensitivity, the scattered light detector is provided with switching means. To make switching the device as simple as possible, said switching means can, for example, be a DIL switch.
[0031] It is however also possible to configure the switching means as low-priced jumper connections. In order to increase user-friendliness and monitoring possibilities, it makes sense to provide a communication interface, in particular, to a PC or network. This allows the centralized monitoring of a plurality of scattered light detectors, their diagnostics respectively. When doing so, the given communication paths can be either wireless or wired. It therefore makes commensurate sense to provide a switch input for changing the sensitivity of the scattered light receiver.
[0032] Arranging a temperature sensor in the flow path of the carrier medium enables the temperature compensation as mentioned above. The arrangement of a flowmeter in the flow path of the carrier medium enables the flow detector to be additionally monitored. For example, it would then be possible to issue a signal upon detecting strong flow fluctuations, since they suggest a malfunctioning of the detector and/or the intake assembly. Configuring the air flow sensor and/or the temperature sensor as thermoelectric components thereby represents an economical and optimally compact possibility of providing the scattered light detector with sensors of high precision.
[0033] Additional and/or other aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
[0035] FIG. 1 is a sectional side view of a first embodiment of a scattered light detector;
[0036] FIG. 2 is a top plan view along the A-A line of the sectioned scattered light detector from the embodiment depicted in FIG. 1 ;
[0037] FIG. 3 is a top plan view of a second embodiment of a sectioned scattered light detector;
[0038] FIG. 4 is a top plan view of a third embodiment of a sectioned scattered light detector;
[0039] FIG. 5 is an input/output signal graph of a scattered light detector;
[0040] FIG. 6 is a diagram depicting the changes in pulse width for the drive current of a light source in relation to temperature.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0041] Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.
[0042] Embodiments of a scattered light detector 1 used as a component of an aspiration fire alarm system are described below. For reference, the carrier medium is air. This air is suctioned in by a ventilator, as is customary in aspiration fire alarm systems. It is thereby conceivable to arrange the ventilator directly on housing 10 of scattered light detector 1 or yet also within a ventilation duct system external of scattered light detector 1 . The methods and devices formulated in the claims are implemented and/or used in the following three embodiments.
[0043] FIG. 1 shows a sectional side view of a scattered light detector. The scattered light detector comprises a housing 10 and a circuit board 40 connected thereto. Housing 10 has an inlet opening 3 and an outlet opening 5 . Ventilator housing 6 , containing a ventilator (not shown), is fixed at the inlet opening 3 , said ventilator providing an air flow 8 to flow through detector 1 along flow path 7 (see FIG. 2 ) from the inlet opening 3 to the outlet opening 5 . It is of course also conceivable for the ventilator disposed in ventilator housing 6 to suction air such that an air flow 8 ′ is created which flows in the opposite direction in scattered light detector 1 . In order to avoid the incursion of external light from the outside, the scattered light detector 1 exhibits light traps 30 and 32 on both sides thereof. The scattered light detector 1 is further provided with a light source 9 which directs a light cone 20 to a scattered light center 11 (see FIG. 2 ) lying along flow path 7 . The scattered light detector 1 further exhibits a receiver 13 in the form of a photodiode. A screen 26 is provided between photodiode 9 and scattered light receiver 13 which prevents the light radiated by light source 9 from hitting scattered light receiver 13 directly.
[0044] FIG. 2 shows the first embodiment from FIG. 1 in a sectional top plan view. The orientation to the section corresponds to the A-A intersecting line depicted in FIG. 1 . As shown, air, which flows through scattered light detector 1 from inlet opening 3 to outlet opening 5 ,passes the scattered light center 11 . Any fine particles present in air flow 8 thereby reflect the light emitted by light source 9 , in this case an LED, onto scattered light receiver 13 , which then generates a detection signal once a previously-defined threshold is exceeded. An air flow sensor 25 and a temperature sensor 23 are additionally provided in flow path 7 of the scattered light detector 1 . Air flow sensor 25 serves in the assessing of whether a more continuous or some otherwise specific air flow 8 is flowing through scattered light detector 1 . In the event of air flow fluctuations, it is, for example, possible to issue a corresponding alarm signal. Temperature sensor 23 monitors the temperature in air flow 8 flowing through scattered light detector 1 along flow path 7 in order to, for example, enable temperature compensation. Temperature compensation is addressed further in FIG. 6 .
[0045] FIGS. 3 and 4 are both sectional top plan views of second and third embodiments of scattered light detectors. The scattered light detector depicted in each again exhibits the light source 9 and the receiver 13 , whereby the light cone 20 of light source 9 and a receiver cone 22 of the scattered light receiver 13 each run crosswise (as in the first embodiment) and over a certain section on a center line 58 of flow path 7 . In each case, the flow channel which guides flow path 7 exhibits a bending both in front of scattered light center 11 as well as behind scattered light center 11 . The light traps 30 and 32 , formed in this manner prevent the intrusion of ambient light from the outside, as in the first embodiment.
[0046] The second embodiment, shown in FIG. 3 , includes screens 26 and 28 , which prevent the reflection of the light emitted from the light source 9 directly onto the scattered light receiver 13 . A temperature sensor 23 and an air flow sensor 25 are likewise arranged on the center line 58 of flow path 7 to collect the detection-relevant calibration and monitoring data.
[0047] As in the embodiments depicted before, the third embodiment depicted in FIG. 4 of a scattered light detector also exhibits light traps 30 and 32 . The center axes 18 and 14 of the light source 9 and the receiver 13 , respectively, are aligned such that they run parallel to or along the center line 58 of flow path 7 for a certain segment thereof (e.g., to the two bendings 30 and 32 of flow path 7 ). In this embodiment as well, screens 26 and 28 are provided to prevent detection of false values. An air flow sensor 25 and a temperature sensor 23 are likewise arranged in the flow channel formed near inlet opening 3 . Thus, the temperature and flow rate of an air flow 8 flowing through scattered light detector 1 is checked before it reaches the scattered light center 11 .
[0048] Several processing operations are used in the scattered light detectors 1 , as described above. In more detail, the scattered light signal received by scattered light receiver 13 runs through a calibration operation, a drift compensation operation, a temperature compensation operation, a sensitivity adjustment operation and/or a filter algorithm operation in any order. The calibration operation and drift compensation operation serve in adapting the respective scattered light receiver to, among other things, different carrier media flowing through the flow detector, whereby calibration assumes an air flow 8 , as given under normal conditions, at its respective place of use. Obviously a scattered light detector used in office spaces must be calibrated to a different airflow 8 than a scattered light detector used in clean rooms. This is taken into consideration in the calibration and/or drift compensation operation. The difference between these two operations is that in the drift compensation operation, the so-called chamber value, the scattered light signal detected by scattered light receiver 13 if no smoke or similar foreign matter which could trigger an alarm in scattered light center 11 is detected, is averaged over a longer period of time, which usually means two to three days. This so-called tracked chamber value is then subtracted from the detected scattered light signal in order to calibrate scattered light detector 1 . Adjusting the temperature of air flow 8 is possible in consequence of the temperature signal received from temperature sensor 23 . Here, as noted at the outset, the fact that as the temperature rises, the light output emitted from light source 9 diminishes is taken into consideration. In order to now receive a detected output of scattered light detector 1 independent of temperature, the corresponding adjustment is made in the temperature compensation operation. The scattered light signal detected by scattered light receiver 13 in the different embodiments is additionally filtered differently in a filter algorithm operation. In order to eliminate any possible false signals, it is conceivable to filter the scattered light signal based on its slope prior to comparing it to the preset thresholds which would lead to an alarm signal.
[0049] In order to ensure with all three scattered light detectors as exact and sensitive of a monitoring of air flow 8 as possible, the various embodiments exhibit a scattered light amplifier (not shown) to amplify the scattered light signal detected by scattered light receiver 13 , for example in the form of an integration amplifier. This integration amplifier enables, for example, by modifying the integration time, a change in the sensitivity of scattered light receiver 1 . The greater the integration time selected, the more sensitive the scattered light detector 1 becomes. This change can be made incrementally or continuously.
[0050] FIG. 5 shows a signal input/output graph. Input signal 2 thereby corresponds to an unfiltered signal, as would be detected by scattered light receiver 13 in scattered light detector 1 . Output signal 4 , in contrast, corresponds to a signal which has already been modified by special filter algorithms. Note is to be made here of the four peak values A, B, C, D in input signal 2 , whereby only peak value C exceeds the threshold value of “1” over a longer period of time, based on which an alarm or detection signal will be triggered. In contrast, the so-called deceptive values A, B and D are capped by the filter algorithm and do not lead to an alarm signal. To be noted here is that while false values B and D also exceed the “1” threshold, their exceedance does not last long enough and are thus not recognized as an alarm value by the internal filter and are thus capped. An adapted filter specification can thus yield a scattered light detector which is optimally adapted to environmental and other similar conditions.
[0051] FIG. 6 represents possibilities for compensating temperature in the three flow detectors from FIGS. 1 to 3 . Shown first in Ill. 6.1 is a diagram of the pulsed operation of light source 9 . In normal operation, same exhibits a pulse phase 50 having a pulse width of, for example, three milliseconds, followed by a rest phase 52 of one second. In rest phase 52 , light source 9 cools down while in pulse phase 50 it heats up, so that a consistent temperature profile can be expected in the air flow channel under normal conditions. However, should air flow sensor 25 determine a rise in temperature, it is possible, as depicted in Ill. 6.2 and 6.3, to gradually reduce the pulse width of pulse phase 50 in order to effect a lower resulting temperature for light source 9 . Changing the pulse width of the light emission—this corresponds to changing the pulse width of the drive current for light source 9 —of course also effects a decrease in sensitivity, which can then be compensated accordingly in the sensitivity adjustment step or another calibration step.
[0052] Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
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A method of evaluating a scattered light signal generated by a scattered light receiver when detecting especially fine particles in a carrier medium, wherein the scattered light signal runs through a filter algorithm operation to evaluate the scattered light signal subject to specific filter algorithms, the filter algorithm operation being based on a slope of the scattered light signal.
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FIELD OF THE INVENTION
The present invention relates to control of drills of the type used to drill holes in earth formations. More particularly, the invention relates to a method and apparatus for controlling the axial force applied to a drill bit and the rate of rotation of the drill bit to obtain more efficient utilization of the bit with minimum vibration.
BACKGROUND OF THE INVENTION
The Rotary Drill Division of Ingersoll-Rand Company markets vehicle-carried blasthole drills used in the mining industry to drill holes into which blasting charges are inserted and set off to fracture rock formations. Typically, an operator relies on past experience to manually control the axial force applied to the drill bit and the rotational speed of the drill bit, the control being exercised by operation of manual controls provided in the operator's cab of the vehicle. The operator must continuously monitor the drilling operation, varying the rotational speed of the bit and the axial force applied to the bit as the bit moves through rock, less dense material and voids. The constant supervision results in operator fatigue. Furthermore, if the operator sets the rotation speed too high, vibration may be induced which could damage the drill. Also, in very soft material, applying too high an axial force could create such a volume of rock chips that the forced air removal system could not handle them and that could lead to plugging the air jets in the bit and result in interruption of the drilling process to clear the jets. In addition, an excessive axial force applied to the bit adversely affects the useful life of the bit.
Extensive field testing of rotary drills having tricone bits has shown that for a given type of rock the penetration of a bit, per revolution of the bit, is a unique function of the axially directed force applied to the bit and, for efficient utilization of the bit, the penetration of the bit per revolution (P/R) should not grossly exceed the height of the cutting elements of the bit. Tests further show that for a given axial force (FB), the absolute rate of advance of the bit into the formation is a unique function of the angular speed (N) of the bit. The limiting factor on how fast a bit can be rotated is the onset of drilling vibration. Finally, it has been observed that if the pressure in the forced air removal system rises above a normal operational value for a given drilling system, such rise is an indication that the advance of the bit per revolution of the bit is too high and plugging of the nozzles in the bit could occur.
Jasinski U.S. Pat. No. 4,793,421 discloses a control system wherein the axial force applied to a bit and the rotational speed of the bit are controlled at the maximum values possible without causing components and/or subsystem overloading to occur. This system does not control P/R to any reference value.
Zhulovsky et al. U.S. Pat. No. 4,354,233 discloses a control system for controlling P/R and the product (FB)(N), these values being referred to as Z and F/Z, respectively, in the patent. Z and F/Z are controlled so as to be as close as possible to values Z 0 and (F/Z) 0 that are continuously calculated by a microprocessor. Z 0 and (F/Z) 0 are presented as the optimum values for the drill to operate at for any given type of rock, based on various criteria built into the logic of the microprocessor. As the drill bit passes from one type of rock to another, the microprocessor calculates the appropriate values of Z 0 and (F/Z) 0 for Z and F/Z to be compared against. A two-step control sequence is employed. If something causes Z to not equal Z 0 , a signal is sent to a rotation frequency regulator that in turn causes the bit rotation speed to change. This in turn causes F/Z to not equal (F/Z) 0 so a signal is sent to an axial load regulator to change the axial force applied to the bit.
From extensive field test data, it can be shown that P/R (Z in the reference) is in no way affected by a change in N alone. Therefore, the first step in Zhulovsky produces no direct result in terms of a change in P/R. It is only because of the second step (changing the axial force) that any change in P/R occurs.
Because F/Z in Zhulovsky is actually the product of FB and N, any change in N will produce a reciprocal change in FB for the product to remain constant. On the other hand, it is an operational advantage to have FB and N independently controllable.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method and apparatus for automatically controlling a drill in a manner which results in higher drill productivity and better utilization of the bit.
Another object of the invention is to provide a method and apparatus for controlling the axial force applied to a drill bit according to the rock specific fracture energy or the work which must be put into the bit to produce a hole.
A further object of the invention is to provide a method and apparatus for controlling the force applied to a drill bit so that axial advance of the bit, per revolution of the bit, is approximately equal to, or does not grossly exceed, the height of the cutting elements on the bit when drilling competent rock. The axial force applied to the bit is automatically decreased as the drill bit passes through less dense material or voids.
Yet another object of the invention is to provide a method and apparatus for controlling a drill by sensing the rate of rotation of the drill bit, the instantaneous axial position of the bit, the pressure of the air being applied to the bit, and indications of the rotational torque required to rotate the bit and the axial force applied to the bit, computing the penetration of the bit per revolution of the bit and the rock specific fracture energy from the sensed values, selecting a desired penetration per revolution according to the calculated rock specific fracture energy, and selectively increasing or decreasing the axial force applied to the bit when the actual penetration per revolution is respectively less than, or greater than the desired penetration per revolution.
Still another object of the invention is to provide a method and apparatus as described above wherein the axial force applied to the bit is decreased, if the pressure of the air supplied to the drill bit, the torque required to rotate the bit, or the axial force applied to the bit, exceeds a predetermined reference level.
A further object of the invention is to provide a method and apparatus as described above wherein vibration of the drill is sensed and the rate of rotation of the drill bit is drastically reduced when the vibration exceeds a reference level.
Other objects, features and advantages of the invention will become obvious from consideration of the following description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically represents an electro-hydraulic drill control system according to the present invention;
FIG. 2 is an elevation view of a drill tower and drill head;
FIG. 3 schematically illustrates a mechanism for raising and lowering a drill bit; and,
FIGS. 4A and 4B comprise a flow diagram of a program for controlling axial feed and rotational speed of a drill bit.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is suitable for use in drills such as the Model DM-L and DM-H blasthole drills available from the Rotary Drill Division of the Ingersoll-Rand Company and will be described in that environment although it will be evident from the following description that the invention may be used with other drills. A blasthole drill typically includes a tower or mast 10 (FIG. 2) which is supported on a vehicle platform in the manner shown in U.S. Pat. No. 5,201,816. A drill head 12 is mounted for vertical movement within tower 10. The drill head includes a frame or support 14 having guide flanges 16 which engage two front upright members 18 of the tower. Mounted on top of the support 14 are two bi-directional hydraulic rotation motors 20 and 22. These motors drive a head spindle 24 through gearing and the bearings that support the spindle being designed to impart rotational movement to the spindle and also apply a downward thrusting force to the spindle along an axis 26.
The spindle 24 is hollow and hollow pipe 28 is connected to the spindle. At the lower end of the pipe is a drill bit 30 having jet openings (not shown) therein. Air under pressure is applied to an air swivel housing 32 located on support 14. The air under pressure flows through spindle 24 and pipe 28 and out the jet openings in bit 30 to flush the cuttings produced by the drilling process away from the bottom of the drilled hole and up and out of the hole.
The drill head 12 is moved up and down within tower 10 by a chain and sprocket arrangement illustrated in FIG. 3. A first chain 40 is attached to one side of support 14 and looped around a first idler sprocket 42 and a first driven sprocket 44. A second chain 46 is attached to the opposite end of support 14 and looped around a second idler sprocket 48 and a second driven sprocket 50. The idler sprockets 42 and 48 are mounted within the tower near the top thereof and the driven sprockets are mounted within the tower near its bottom. Sprockets 44 and 50 are driven by bi-directional hydraulic feed motors 52 and 54, respectively.
Motors 52 and 54 are actuated concurrently but drive sprockets 44 and 50 in opposite directions as viewed in FIG. 2. When sprocket 44 is driven clockwise and sprocket 50 is driven counter-clockwise, the drill head 12 is pulled downwardly, thereby increasing the downward axial force or thrust on drill pipe 28 and bit 30. On the other hand, when sprocket 44 is driven counter-clockwise and sprocket 50 is driven clockwise, drill head 12 is moved toward the top of the tower thus raising bit 30 out of a drilled hole.
A cable 56 is wound on a spring-loaded reel 58 and attached at one end to support 14. The reel 58 is mounted at the top of tower 10 and drives an encoder 60 (FIG. 1) which produces an encoded output signal indicating the instantaneous vertical position Y of the bit 30.
A sensor 70, which may be a magnetic sensor, is mounted on support 14 and senses the passage of teeth on a gear (not shown) in the gear train which drives the spindle 24. The frequency of the output signal from sensor 70 is an indication of the rate of rotation N of the bit 30.
FIG. 1 shows a conventional electro-hydraulic system including an auxiliary pump 102, a feed pump 104 for supplying motive fluid to feed motors 52 and 54, a rotation pump 106 for supplying motive fluid to rotation motors 20 and 22, an electro-hydraulic valve 118, a feed pump pressure compensator 122 associated with feed pump 104, and a displacement control 124 for controlling the displacement of rotation pump 106.
FIG. 1 further shows a control system according to the present invention for controlling the rotational speed N of bit 30 and the force FB applied parallel to and coincident with the axis 26 of the bit, the control system including a controller 100, an operator's keyboard or control panel 101, the encoder 60, the sensor 70 and a plurality of further sensors 110, 112, 114 and 116.
Controller 100 may be a conventional microprocessor with memory, including a non-volatile memory capable of retaining information when power is turned off, A/D and D/A converters, and a continuously running clock or timer. The controller receives a digitally encoded signal from encoder 60 indicating the instantaneous vertical position Y of bit 30. The controller also receives analog input signals from sensors 70, 110, 112, 114 and 116 and performs A/D conversion on the sensor signals to produce digital values used in computation. The controller determines if the axial force FB on the bit 30 should be incremented or decremented and also determines if the rotation speed (N) of the bit should be incremented or decremented. Based on these determinations, the controller derives two digital values representing the desired force on the bit and the desired rotational speed of the bit. The derived digital values are set into two output registers within the controller and the contents of the registers are applied through D/A converters in a well-known manner so that analog output signals are developed on output leads 118 and 120 to control the feed pump 104 and rotation pump 106, respectively.
Sensor 110 is a pressure sensor for sensing the air pressure AP applied through pipe 28 to bit 30. Sensor 110 is preferably located at some point in rigid air piping located on the tower.
Sensor 112 is a vibration sensor which may be mounted on the drill head 12. One or more additional vibration sensors may be provided at other locations such as, for example, at or near the bottom of tower 10. The vibration sensor or sensors may be conventional acceleration, displacement, or strain gage sensors such as those used to measure structural loading.
Sensor 114 is a pressure sensor which monitors the pressure on the inlet side of the feed motors 52 and 54 when they are driven in the direction causing downward movement of the drill head 12. For any given drill rig, there is a fixed relationship between the feed pressure applied to the motors 52, 54 and the axial thrust FB applied to the bit hence an electrical output signal produced by sensor 114 provides an indication of the thrust FB.
Sensor 116 is a pressure sensor for monitoring the pressure on the inlet side of rotation motors 20 and 22 when they are driven in the forward or drilling direction. In this regard, even though motors 20 and 22 are reversible, they are driven in the reverse direction only when disconnecting the drill pipes or bit. For any given drill rig, there is a fixed relation between the rotation pressure applied to motors 20, 22 and the torque produced by the motors to rotate the bit hence an electrical output signal produced by sensor 116 provides an indication of the rotational torque RT being applied to the bit.
The feed motors 52, 54 for moving the drill head vertically are connected in a hydraulic circuit in which the motive fluid is pumped by feed pump 104. The pump 104 is provided with a pressure compensator 122 that is responsive to the pressure in a line 126 extending between auxiliary pump 102 and electro-hydraulic valve 108. Controller 100 produces, on lead 118, an analog electrical signal indicating the force FB to be applied to the bit 30. For a fixed voltage signal on lead 118, the valve is controlled to give a certain pressure in the line 126 for the feed pump compensator 122 to hold. The feed pump 104 then provides just that amount of fluid to the feed motors 52, 54 to maintain, but not exceed, that pressure.
Rotation pump 106 pumps the hydraulic fluid for driving the drill rotation motors 20 and 22. Pump 106 is provided with an electro-hydraulic pump displacement control 124 of conventional design. Controller 100 provides an analog output signal over lead 120 to the displacement control, the analog output signal indicating the desired rotation speed N of the bit. For a given magnitude of the signal on lead 120, the displacement control 124 sets the displacement of rotation pump 106 so that the pump provides a fixed flow to motors 20, 22 regardless of whether the rock being drilled is hard or soft. Therefore, the rotation pressure automatically adjusts itself depending on how much torque (RT) is required to rotate the bit at the desired speed.
FIGS. 4A and 4B illustrate a program executed by controller 100 to control rotation pump 106 and feed pump 104 in response to the conditions sensed by encoder 60 and sensors 70, 110, 112, 114 and 116. The program is repeatedly executed only during the time an auto/manual control switch (not shown) on control panel 101 is set to the "auto" position by an operator. When the switch is set to the "manual" position, the operator may manually operate control levers to generate electrical signals which are applied over leads, not shown, to valve 108 and displacement control 124 to control feed pump 104 and rotation pump 106.
Two memory locations Y1 and Y2 are used to store indications of the vertical position Y of the bit at two successive sensings of the vertical position. At step 200 a previously sensed value of Y is transferred from Y2 to Y1 and at step 202 the controller senses encoder 60 and stores the current indication of the bit position in Y1.
Two memory locations T1 and T2 are used to store indications of the times at which two successive sensings of the vertical position of the bit occur. Step 200 transfers the time of the previous sensing from T2 to T1. At step 202 the controller senses an internal timer T and loads into T2 the time at which the current sensing of Y takes place.
At step 202 the controller also samples the output signals from sensors 112, 110, 114 and 116 and stores digital indications of the magnitudes of the signals at memory locations DV, AP, FB and RT, respectively. The sensed value of rotational torque is "normalized" prior to storage in RT by subtracting from the sensed value a stored value representing the torque required to rotate the drill bit even though it is not drilling.
The controller derives the rate of rotation N of the bit in a conventional manner by sensing the contents of a register which holds an indication of the rate of rotation of the bit. In this regard, a timer within the controller counts timing pulses during intervals of time elapsing between sensing of successive gear teeth by sensor 70. The contents of the counter are transferred to a register and the counter is reset as each gear tooth is sensed. The register is sensed at step 202 and the value therein is multiplied by an appropriate conversion constant to convert the counter value to an indication of the rotational speed N.
If more than one vibration sensor is provided, all of the sensor output signals are sampled at step 202 and stored at different locations in memory. At step 204, the drill vibration value (or values) is/are compared with a maximum value DV MAX . DV MAX may have a different value for each vibration sensor. If none of the sensed drill vibrations is greater than its corresponding DV MAX , the program advances to step 206 where the controller calculates P/R, the advance of bit 30 per revolution. P/R is determined by subtracting the last previous bit position sensed from the current position sensed when step 202 was last executed to determine the change in vertical bit position. The difference between T2 and T1, when multiplied by the rotational speed N of the bit yields a value representing the angular movement of the bit during the interval of time which elapsed between the two sensings of the vertical position. Dividing the change in vertical bit position by the angular movement of the bit as it is moved between the two positions yields P/R, the penetration of the bit per revolution.
At step 206 the controller also calculates the rock specific fracture energy (Es) which is a measure of the work put into the bit to drill the hole, and an indication of the density or hardness of the material through which the bit is passing. Es is calculated by dividing RT by the product of P/R times the area of the hole Ah being drilled, and multiplying the result by a constant K. Different values of Ah corresponding to different diameters of drill bits may be stored in memory and the correct value may be selected from the control panel 101 by the operator prior to initiation of a drilling operation.
The air pressure AP sensed in pipe 28 is then compared (step 208) with a value AP MAX stored in non-volatile memory. The pressurized air in pipe 28 exits through jets in bit 30 and conveys drilled rock chips and dust away from the bit and upwardly and out of the drilled hole. If the bit is advanced too fast the pressurized air cannot convey the chips and dust away from the bit and the chips and dust accumulate around the bit until the flow of pressurized air is completely blocked. As the accumulation begins, the pressure in pipe 28 begins to rise. AP MAX is chosen to be greater than the pressure normally present in pipe 28 if the chips and dust are being freely conveyed out of the drilled hole but considerably less than the pressure that would be present in pipe 28 when the chips and dust completely clog the hole. Thus, step 208 senses for the onset of clogging. If step 208 determines that AP is greater than AP MAX , FB is decreased at step 210 and at step 212 the decreased value of FB is set into an output register to decrease the magnitude of the signal applied over lead 118 to valve 108. As a result, the valve opens somewhat so that the pressure in line 126 decreases. The feed pump pressure compensator then responds to the reduced pressure in line 126 and the flow from feed pump 104 to the fluid motors 52, 54 is correspondingly controlled to maintain a decreased pressure. Because the feed pressure is decreased, the axial force applied to the bit 30 decreases. The drill bit crushes away less rock thus permitting the accumulation of chips and dust to be cleared by the air being forced out of the drill bit.
If the comparison at step 208 shows that AP is not greater than AP MAX , step 214 is executed to compare RT with RT MAX . RT MAX is a value stored in non-volatile memory and represents, for a specific drill, the maximum rotational torque which should be applied to rotate the bit. RT is primarily a function of P/R and P/R is only a function of FB. If RT is greater than RT MAX , FB is decreased (step 216) and set into the output register (step 212) to cause a decrease in the axial force on the bit as previously described. The displacement control 124 sets rotation pump 106 to produce a fixed flow for a given magnitude of signal on lead 120. The rotation pressure applied to motors 20, 22 varies depending on the torque, RT, required to rotate the bit. A decrease in FB will cause RT to decrease and that will cause a decrease in the pressure in line 128, which is sensed as an indication of RT. So, the next time the program executes step 202, a lower value of RT will be sensed.
If the comparison at step 214 shows that RT is not greater than RT MAX , step 218 is executed to compare FB with FB MAX . FB MAX is a value stored in non-volatile memory and represents, for a specific drill, the maximum axial force which may be applied to the drill bit, If the comparison at step 218 determines that FB is greater than FB MAX , then FB is decreased at step 220 and transferred to the output register (step 212) to decrease the axial force applied to the bit, as described above.
If the comparison at step 218 determines that FB is not greater than FB MAX , step 222 is executed to compare the value Es, computed at stp 206 with (Es ref ). The value of (Es) ref is chosen according to the density or hardness of the material to be drilled. For example, (Es) ref may be set to a value somewhat less than the Es for competent rock.
If Es is greater than (Es) ref then at step 224 the value of P/R computed at step 206 is compared with a value (P/R) A . (P/R) A is a value related to the height of the cutting elements on the bit and is chosen to be approximately equal to, or not grossly exceeding the height of the cutting elements. If P/R is greater than (P/R) A then FB is decreased at step 226 but if P/R is not greater than (P/R) A then FB is increased at step 228. The increased or decreased value of FB is then loaded into an output register to generate a signal for controlling valve 108 as previously described.
If the comparison at step 222 shows that Es is not greater than (ES) ref then Es is tested at step 230 to determine if it is zero. If Es is not equal to zero then at step 232 P/R is compared with (P/R) B . (P/R) B is a fixed value chosen to be larger than the height of the cutting elements of bit 30 so as to allow faster drilling speeds in soft material. If the comparison at step 232 shows that P/R is greater than (P/R) B then FB is decremented at step 234 before being transferred to the output register at step 212. On the other hand, if P/R is not greater than (P/R) B then FB is incremented at step 236 before being transferred to the output register.
If the test at step 230 shows that Es is zero then the drill bit is passing through a void and axial advance of the drill bit should be increased, but not to the extent that the bit will be jammed with too much force into a rock formation which may be underneath the void. At step 238 P/R is compared with (P/R) C , a stored constant value representing a safe penetration of the bit, per revolution, through voids. If the comparison shows that P/R is greater than (P/R) C then FB is decremented (step 240) and transferred to the output register (step 212) to cause a reduction in P/R of the bit. On the other hand, if P/R is not greater than (P/R) C then FB is incremented (step 242) before being transferred to the output register to cause an increase in the P/R of the bit.
The controller 100 controls the rotation speed (N) of bit 30 independently of the P/R of the bit. Generally speaking, N is controlled to be equal to N MAX where N MAX is the maximum speed at which a particular drill should be operated. However, if speed N causes drill vibration DV with a root-mean-square value exceeding DV MAX , the maximum allowable vibration, then the rotation speed is drastically reduced. This simulates the manual control where an operator merely reduces the drill speed at the onset of excessive vibration. Typically, the rotation speed may be reduced by 50% but this may vary over a wide range.
FIG. 4B illustrates the portion of the program executed by controller 100 to control the rotational speed N of the bit 30. At step 250, which may follow step 212. The controller obtains the current values of N and DV in the same manner as described with respect to step 202. Step 252 compares N with N MAX and if N is not greater than N MAX N is incremented at step 254. DV is then compared with DV MAX (step 256) and if DV is not greater than DV MAX the incremented value of N is entered into an output register (step 258) to set (increase) the magnitude of the signal applied over lead 120 to the rotation pump displacement control 124. This causes the rotation pump 106 to increase the flow to rotation motors 20, 22 thus increasing the rotation speed of the bit 30.
If the comparison at step 252 determines that N is greater than N MAX then N is decremented at step 260 before being loaded into the output register (step 258) to decrease the magnitude of the signal applied to the displacement control 124.
If the comparison of DV with DV MAX at either step 204 or step 256 determines that DV is greater than DV MAX then N is reset at step 262 to some value N 0 low enough to insure that DV will drop below DV MAX . The new value of N is then transferred to an output register (step 258) to reduce considerably the magnitude of the signal on lead 120 thereby causing the rotation motors 20, 22 to rotate the bit 30 at a much lower speed.
Although FIG. 4A shows control of the axial feed rate according to only three ranges of Es (steps 222 and 230) it will be understood that the algorithm may be expanded to differentiate between more values of Es with additional values of P/R X being used to obtain different bit feed rates.
From the foregoing description it is seen that the present invention provides a novel method of controlling a drill by determining (step 206) the actual penetration of the drill bit per revolution of the bit, determining the rock specific fracture energy Es (step 206), based on the magnitude of Es (steps 222, 230) selecting a desired penetration of the bit per revolution (P/R) A , (P/R) B , (P/R) C and selectively increasing and decreasing the axial force (steps 226, 228, 234, 236, 240 and 242) applied to the bit in order to maintain the actual penetration of the bit per revolution of the bit approximately equal to the desired penetration of the bit per revolution.
While the invention has been described in conjunction with a specific drill, it may be used in the control of drills of various types. For example, the invention may be used to control drills employing a piston-cylinder arrangement rather than a chain and hydraulic feed motors for vertically moving the drill head. Also, the invention is applicable to drills having only one axial feed motor and/or one rotation motor. The method of the invention may also be practiced with drills having an electric motor or motors as the feed and/or rotation motors.
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A blasthole drill is provided with sensors for sensing the pressure (AP) applied to and through a drill bit to convey cuttings from the drill hole, the rate of rotation (N) of the drill bit, the torque (RT) required to rotate the bit, the force (FB) applied axially to the bit and the instantaneous vertical position (Y) of the bit. Output signals from the sensors are applied to a microprocessor-based controller which computes the penetration of the drill bit per revolution of the bit (P/R) and the rock specific fracture energy (Es). Using the sensed values and the computed values, the controller produces output signals to increment/decrement the force (FB) applied axially to the drill. The applied axial force is controlled such that the penetration of the bit per revolution remains substantially constant for a given range of values of the rock specific fracture energy but varies for different ranges of the rock specific fracture energy. The rate of rotation of the drill bit is controlled to a reference value. Drill vibration sensors provide further input signals to the controller and when the vibration exceeds a predetermined limit the rate of bit rotation is immediately decreased.
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BACKGROUND OF THE INVENTION
[0001] The invention concerns a conveyor arrangement for shock-sensitive products, such as eggs or the like, and includes a conveyor apparatus for conveying the products, an intermediate storage region which is adapted to receive products temporarily by virtue of discontinuous feed or discharge, and a control device for increasing the discharge and/or for reducing the feed of products into the intermediate storage region of the conveyor apparatus when a predetermined critical number of products is exceeded in the intermediate storage region.
[0002] Conveyor arrangements are generally used for transporting eggs away from a laying area and feeding them to a packaging station. That purpose is served by using particular conveyor arrangements which include a transverse conveyor belt which conveys products to a processing station and a plurality of longitudinal conveyor belts which are so arranged that they convey products from various, mutually spaced locations onto the transverse conveyor belt. In such devices, the longitudinal conveyor belts extend along a row of henhouses or aviaries and are generally provided individually for each level or tier. The transverse conveyor belts are typically mounted at a right angle to the longitudinal conveyor belts which are disposed in a parallel relationship, and receive the eggs which are transported by the longitudinal conveyor belts out of the laying areas.
[0003] A first problem arising with such prior conveyor arrangements is that conveyance of the eggs on the longitudinal conveyor belts, which extends over a period of time, causes the feed of the eggs by way of the transverse conveyor belt to the processing station to be discontinuous, and in an amount which is insufficient to make full use of the processing capacity of the processing station. To avoid this problem, it is known for a plurality of longitudinal conveyor belts to be simultaneously activated to supply the transverse conveyor belt with an adequate amount of eggs. A problem with that procedure, however, is that the spaced points of entry of the longitudinal conveyor belts mean that the transverse conveyor belt cannot be filled uniformly, and the transverse conveyor belt capacities are exceeded locally, which usually leads to damage to the eggs.
[0004] A further problem with such prior conveyor arrangements is that only low egg conveyor rates are achieved at both the beginning of the conveyor cycle or operation, and at the end of the cycle, since an excessively low level of supply to the transverse conveyor belt occurs by virtue of starting up the first longitudinal conveyor belt and allowing the last longitudinal conveyor belt to run down. That increases or prolongs the processing time at the processing station, which is disadvantageous for cost reasons.
[0005] Particularly in relatively large henhouse installations, it is often desirable for the eggs to be collected in batches or groups from given locations, for example because certain henhouses involve the administration of a different feed from other henhouses, and the eggs produced in that way are to be supplied as an interrelated assembly to the processing station in order to be jointly processed, for example packaged. It is in precisely such situations where the egg collecting operation, with for example up to 15 different groups, takes place in succession. However, it is not possible to achieve full utilization of the processing capacity of the processing station at all times with the previously known measures of simultaneously switching on different longitudinal conveyor belts so that, in such situations of use, considerably longer operating times in the processing station and consequently longer collecting times and higher operating costs have to be tolerated.
[0006] A further problem with such prior conveyor arrangements involves in particular keeping laying hens in an aviary in animal-friendly conditions. In such a situation, the animals are provided with a nest in which the animals preferably lay their eggs. The eggs roll onto the longitudinal conveyor belt from the nest. However, the locally concentrated accumulation of the laid eggs results in overfilling of the longitudinal conveyor belt in the nest region, and that can lead to damage to the eggs. In contrast, keeping the hens in cages leads to the laid eggs being distributed over the entire cage width, and consequently, one-off or sequential activation of the longitudinal conveyor belts per day would be sufficient to collect the laid eggs, it being necessary when keeping the birds in animal-friendly aviaries for the collecting operation to be carried out a number of times daily by virtue of local overfilling of the longitudinal conveyor belts.
[0007] Yet a further problem with such prior conveyor arrangements is that a build-up can occur due to congestion or processing problems upstream of or in the processing station, and as a result, high damaging forces can act on the eggs. To avoid that problem, it is known to provide a limit switch which is actuated by the egg collection, and which switches off the transverse conveyor belt when an inadmissibly high force occurs. However, from the point of view of utilizing the full capacity of the processing station, a certain build-up or accumulation upstream of the processing station is desired as a buffer, switching off the transverse conveyor belt in that way results in the transverse conveyor belt being very frequently switched on and off, and that can cause increased wear and premature failure.
[0008] Finally, a further problem with known conveyor apparatuses is that, when supplying products from a plurality of conveyor belts to a common collecting conveyor belt, damage to the products often occurs if the additionally supplied products first have to displace the products which are already on the collecting conveyor belt, and in that case, unacceptably high forces are operative between the products. To avoid such damage, it is known to provide product guide devices which are stationarily fixed in position relative to the movement of the collecting conveyor belt, and which guide the products already on the collecting conveyor belt upstream of the entry regions of further products in such a way that they are guided away from the entry region and space is thus made available for the products which are additionally arriving. Those product guide devices have to be regularly repositioned and set to accommodate changing delivery conditions, either due to delivery from different delivery conveyor belts or due to varying delivery conveyor quotas, and that makes handling thereof more difficult.
SUMMARY OF THE INVENTION
[0009] One object of the present invention is to provide a conveyor arrangement which avoids one, and preferably a plurality, of the aforementioned problems.
[0010] In accordance with one aspect of the invention, a force measuring device is provided which is adapted and arranged to detect a force which is exerted by the products disposed in an intermediate storage region, and which represents a measurement of the number of products in the intermediate storage region, and a control device adapted to process the force detected by the force measuring device as an input parameter, and to increase or reduce the discharge and/or feed of the products from/to the intermediate storage region in accordance with the force value.
[0011] The invention makes it possible for the first time to achieve differentiated actuation of the discharging and feeding conveyor apparatuses, in accordance with the force responsible for damage to the products. In that way, the filling of the intermediate storage region that is sought to be achieved, for example to supply a processing station or to receive products from a product region, can be effected in a very much more specific and targeted fashion, and it is thus possible to achieve an intermediate storage region filling effect, without the frequent starting and stopping of the conveyor apparatus as is required in the state of the art.
[0012] In that embodiment, it is particularly preferred that the control device is adapted to actuate the conveyor apparatus at a first and a second conveyor speed, wherein the second speed is higher than the first speed. In that way, it is possible to select a suitable speed depending upon on the force measurement value in order to increase or reduce the number of products in the intermediate storage region. Thus, upon a reduction in the detected force, the second speed can be selected while upon an increase in the detected force, the first speed can be selected. Furthermore, the first and second speeds can be set when the force values fall below or exceed predetermined force limit values.
[0013] It is further preferred that the control device is adapted to adjust the conveyor apparatus preferably steplessly in accordance with the force detected by the force measuring device. Stepless control of the conveyor apparatus allows highly precise regulation of the number of products in the intermediate storage region or the force occurring between the products.
[0014] It is further preferred that the control device is adapted to reduce the feed of products to the intermediate storage region and/or to increase the discharge from the intermediate storage region when a predetermined force value is exceeded. That provides for simple and reliable control or regulation of product conveyance.
[0015] In a particularly preferred embodiment of the conveyor arrangement, the force measuring device is arranged beneath the products in the intermediate storage region in order to measure in a vertical direction and to detect the total or cumulative force due to weight of the products in the intermediate storage region. This arrangement is particularly suitable for use in the region of a nest when animals are being kept in an aviary situation. In that respect, the force measuring device can be so arranged that it measures the force due to weight of the eggs on the longitudinal belt in the region of the nest, and causes a conveying movement on the part of the longitudinal conveyor belt when a predetermined force due to weight is exceeded in order to prevent a build-up of the eggs.
[0016] In that embodiment, it is particularly preferred that the force measuring device is coupled to a horizontally arranged weighing plate arranged beneath a conveyor belt on which the products are arranged in the intermediate storage region. Weighing of all the products in the intermediate storage region is thus achieved in a reliable and structurally robust fashion.
[0017] In particular, it is preferable that the control device is adapted to actuate the conveyor apparatus from a stopped condition when a predetermined cumulative force due to weight of the products in the intermediate storage region is exceeded, so that the products are further conveyed to such an extent that all products are conveyed out of the intermediate storage region. In that way, a conveying action, partial or complete, is implemented in accordance with the products in the intermediate storage region, and it is possible to avoid a build-up.
[0018] It is particularly preferred that the conveyor apparatus includes a conveyor belt on which the intermediate storage region extends by a given length, and the control device is adapted so that the conveyor belt is further conveyed by precisely the length of the intermediate storage region when a predetermined cumulative force caused by the weight of the products in the intermediate storage region is exceeded. That arrangement provides that, upon complete filling of the intermediate storage region, the conveyor belt is advanced, only to such an extent that the subsequent filling of the conveyor belt occurs in a region directly adjoining or adjacent to the previously filled region, and in that way, complete filling of the longitudinal conveyor belt is progressively achieved over a large region.
[0019] Thus, in one aspect of the conveyor arrangement, a plurality of mutually spaced intermediate storage regions are arranged along the conveyor belt, and the control device is so adapted that when a predetermined cumulative force caused by the weight of the products is first exceeded in an intermediate storage region, the conveyor belt is further conveyed by the length of the intermediate storage means. When a predetermined cumulative force due to the weight of the products is subsequently exceeded in the intermediate storage region, the conveyor belt is conveyed further once again by the length of the intermediate storage means, and that procedure is optionally repeated up to a predetermined number of repetitions until the conveyor belt is full. The conveyor belt is then driven until the products are conveyed from the conveyor belt onto a second conveyor apparatus or into a storage space.
[0020] In this embodiment, when using the conveyor arrangement as a longitudinal conveyor belt, a multiple advance movement of the longitudinal conveyor belt is effected in a stepwise fashion over a discrete advance distance which corresponds to the length of the intermediate storage region. In that way, adjacent regions on the longitudinal conveyor belt are filled in succession over time. A plurality of nest regions are usually arranged along the longitudinal conveyor belt, and then after a given number of such discrete advance movements, a longitudinal conveyor belt portion, which is filled up by an adjacent nest region, would be conveyed into the nest region of a juxtaposed aviary, and in that case, there would be the danger of a build-up of eggs occurring, as there is no longer any free longitudinal conveyor belt region available. Therefore, when the longitudinal conveyor belt is typically completely filled, continuous activation of the longitudinal conveyor belt is implemented in order to convey the eggs toward a storage space, for example onto a transverse conveyor belt.
[0021] A further development of the conveyor arrangement includes providing a plurality of conveyor belts, each having at least one respective intermediate storage region, arranged so that at least one intermediate storage region includes a force sensor for measuring the force due to the weight of the products in the intermediate storage region, and the control device is so adapted that all conveyor belts are further conveyed by the length of the intermediate storage means when a predetermined cumulative force due to the weight of the products in that intermediate storage region is exceeded. That arrangement is suitable in particular for a plurality of henhouses, and is based on the realization that typically each aviary has a similar laying capacity, so that it is sufficient if the laid eggs are weighed only in the region of the nest of one aviary, and then all conveyor belts are advanced when a given force or weight value in that region is exceeded.
[0022] A further aspect of that arrangement includes providing a plurality of conveyor belts, each having at least one respective intermediate storage region with a force sensor for measuring the force caused by the weight of the products in the intermediate storage region, and a control device adapted so that all conveyor belts are further conveyed by the length of the intermediate storage means when the force due to the weight of the products in one intermediate storage region with force sensor, or the mean value of the force due to the weight of the products in all intermediate storage regions with force sensor, exceeds a predetermined force due to the weight of the products. With this embodiment, a greater degree of security or precision in relation to irregularities in the laying capacity is achieved, insofar as the laid eggs of a plurality of aviaries are measured, and then all longitudinal conveyor belts are advanced in dependence on those measurement values.
[0023] In a second particularly preferred configuration of the conveyor arrangement according to the invention, the force measuring device is coupled to a movable wall portion to detect the horizontal surface pressure exerted by the products on the movable wall portion as a pressing force on the movable portion. This feature is particularly suitable for monitoring the eggs conveyed by the transverse conveyor belt in the region upstream of a packaging station to avoid damage to those eggs if build-ups occur in the packaging station. Detection of a differentiated pressing force allows precise control of the supply of eggs and avoids damage or frequently recurring stopping and starting of the transverse conveyor belt.
[0024] In that embodiment, it is particularly preferred that the force measuring device is coupled to a movable wall portion to detect the horizontal surface pressure exerted by the products on the movable wall portion as a pressing force on the movable portion. That feature provides for precise measurement of the pressing force, and thus generates an input parameter which is reliable for the control or regulating action. In that embodiment, it is alternatively possible to provide a plurality of force measuring devices, each having a respective movable wall portion, which for example, can lie laterally and in opposite relationship to the products which are being conveyed therethrough, or which can also be arranged in the form of a measuring island in the flow of products.
[0025] A further development in the embodiments with a horizontally measuring force sensor is providing the movable wall portion with a first wall surface region which faces in opposite relationship to the feed conveyor device into the intermediate storage region, and a second wall surface region which faces parallel to the feed conveyor device. It has been found that the provision of two such wall surface regions provides for detection, which is desirable in terms of ascertaining the actual product loading of the conveyor force in the conveyor direction and the transverse force produced thereby with respect to the conveyor direction, which represents an input parameter directly related to the risk of product damage, for the regulating or control action.
[0026] In that embodiment, the movable wall portion can be of a half-round shape. Thus, a preferred structure is a half-round wall portion, which is mounted pivotably at one end, and spaced from that mounting is coupled to the force sensor and transmits a force to the sensor.
[0027] In accordance with a second aspect of the invention, to avoid the above-discussed disadvantages of known conveyor arrangements, there is proposed a conveyor arrangement, comprising a conveyor apparatus for conveying the products, an intermediate storage region which is adapted to receive products which are to be put temporarily into intermediate storage by virtue of discontinuous feed or discharge, a control device for increasing the discharge and/or for reducing the feed of products into the intermediate storage region of the conveyor apparatus when a predetermined critical number of products is exceeded in the intermediate storage region, wherein the conveyor arrangement is distinguished in that a measuring device is arranged in the intermediate storage region, which is adapted and arranged to detect the number of products standing up in the intermediate storage region, and which represents a measurement of the horizontal force between the products in the intermediate storage region, and the control device is adapted to process the number detected by the measuring device as an input parameter and to increase or reduce the discharge and/or feed of the products from/to the intermediate storage region as a function thereof.
[0028] This aspect of the invention represents an alternative for direct measurement of the force in the intermediate storage region, and is based on the realization that the products accumulated in the intermediate storage region, when a given horizontal pressing force among each other is exceeded, have a tendency to stand up or be arranged in a mutually superposed relationship in the intermediate storage region. The number of the products which project in that way beyond the products, which are lying flat on the base surface of the intermediate storage region, whether that occurs by virtue of the products standing up or by virtue of their being supported on an adjacent product, is a measurement of the magnitude of the horizontal forces between the products in the intermediate storage region, and can therefore be used as an input parameter for the control device. That conveyor arrangement is suitable in particular for conveying eggs which typically, when an increased conveyor pressure is involved, tend to stand up, and accordingly afford a reliable indication in the form of a plurality of eggs standing on their rounded ends, when a predetermined critical horizontal force has been exceeded.
[0029] In that way, the conveyor arrangement can be used in the same fashion as previously discussed for effecting stepless or dynamic transverse belt regulation, which can be regulated as a function of the number of products which are standing up in the intermediate storage region, in a closed regulating circuit.
[0030] The measuring device can be for example in the form of a plurality of light barrier arrangements, which measure horizontally over the products which are lying flat in the intermediate storage region, wherein preferably mutually crossing light paths are used in order to ensure coverage and detection over the area involved.
[0031] It is further preferred that the intermediate storage region is arranged in the transfer region between a first feeding conveyor apparatus and a second discharging conveyor apparatus, and the control device is so adapted that when a predetermined pressing force between the products, or the number of products standing up in the intermediate storage region is exceeded, the conveyor rate of the feeding conveyor apparatus is reduced and/or the conveyor rate of the discharging conveyor apparatus is increased.
[0032] In that embodiment, the predetermined pressing force, or the number of products which are standing up, is selected for example in dependence on the pressure sensitivity of the products being conveyed, and can be stored in table form for typical conveyed products in a memory of the control device or can be input by the user of the conveyor arrangement by way of an operating unit.
[0033] It is further preferred that the conveyor rate of the conveyor apparatus or apparatuses can be altered by a preferably stepless or dynamic alteration in the conveyor speed. A stepless change in the conveyor speed, for example by means of frequency converters and electric drive motors for conveyor belts or bar belt conveyors, makes it possible to achieve particularly precise regulation of the conveyor apparatuses in a closed regulating circuit, and on the one hand, reliably avoids damage to the products, while on the other hand, ensuring that the products are permanently held in readiness in the intermediate storage region.
[0034] In accordance with one aspect of the invention, to avoid the above-mentioned disadvantages, there is further proposed a conveyor arrangement comprising a transverse conveyor belt which conveys products to a processing station, and a plurality of longitudinal conveyor belts which are so arranged that they convey products onto the transverse conveyor belt at various, mutually spaced locations, wherein a development of the conveyor arrangement provides a device for detecting the conveyor advance of the transverse conveyor belt, and a regulating device which is coupled to said device, and which is adapted at the beginning of a conveyor operation of the conveyor arrangement to set the longitudinal conveyor belts in operation in time-displaced relationship as a function of the spacing between the entry points onto the transverse conveyor belt, the processing station, and the advance of the transverse conveyor belt.
[0035] Such conveyor arrangements are used for example to collect the products from production units which are distributed over a large area, and convey them to a common processing station. For that purpose, there are typically provided a plurality of longitudinal conveyor belts which are arranged parallel, and in displaced relationship with each other, and which meet a common transverse conveyor belt at mutually spaced points and convey the products onto the transverse conveyor belt. A problem with such conveyor arrangements is that in discontinuous operation of the longitudinal conveyor belts, a discontinuous feed of the products to the processing station is also realized. Moreover, due to the spatial arrangement involved, full utilization of the capacity of the processing station, and the conveyor capacity of the transverse conveyor belt, which is typically matched to that capacity of the processing station, is not possible. The aforementioned aspect of the invention remedies that disadvantage, insofar as the conveyor advance of the transverse conveyor belt is detected, for example by means of a synchronizing timing means, and a regulating device is used, which regulates the discontinuous activation of the longitudinal conveyor belts on the basis of the conveyor advance and the arrangement of the points of entry of the longitudinal conveyor belts onto the transverse conveyor belt. That regulation can involve on the one hand, activation of the longitudinal conveyor belts (binary regulation), or regulation of the conveyor speed of the longitudinal conveyor belts. Consequently, it is typically possible to implement time-displaced actuation of the longitudinal conveyor belts in such a fashion that the products are conveyed in a closed front, and make full use of the capacity of the transverse conveyor belt, and consequently the capacity of the processing station is also fully utilized. Also, in a situation involving diminishing conveyance of products from an individual longitudinal conveyor belt, another longitudinal conveyor belt, or the other longitudinal conveyor belts, can be increased in their conveying action in order to compensate for that condition, and to initiate compensation in positionally resolved relationship to the transverse conveyor belt at the location at which the deficit has occurred. The regulation of the conveyor arrangement is proposed in a way that makes it possible for the first time to fully utilize the capacity of the processing station in any operating state, and in that respect, to be able to accommodate interruptions in the transverse conveyor belt, and fluctuations in the conveyor efficiency of the longitudinal conveyor belts into the regulating and control procedures.
[0036] In particular, the noted conveyor arrangement can be combined with counting devices for the products, which are arranged at the points of entry of the longitudinal conveyor belts onto the transverse conveyor belt, and which detect and count the products which are delivered from each individual longitudinal conveyor belt. The degree of precision of regulation can be further increased by using or exploiting the numerical data ascertained in that way.
[0037] One particularly preferred feature for the above-described conveyor arrangement is to provide that the regulating device is adapted to first set in operation a first longitudinal conveyor belt, which is most remote from the processing station, and to set in operation a second conveyor belt arranged closer to the processing station at a time at which the transverse conveyor belt has advanced to such an extent that the products delivered by the first longitudinal conveyor belt have reached the entry region of the second longitudinal conveyor belt. That feature provides that, after a stoppage of the installation, in particular after the conveyor arrangement has become completely empty, the transverse conveyor belt is loaded from the plurality of longitudinal conveyor belts in such a way as to avoid only isolated products being arranged over a longer transverse conveyor belt portion, but instead providing that a front of loaded-on products involving the full capacity of the processing station is formed on the transverse conveyor belt, whereby full utilization of the processing station can be implemented at a predeterminable moment in time. That is highly advantageous, for example, for collecting eggs from a plurality of different locations which are spaced from each other to feed the eggs to a packaging station in such a way that the packaging station can be operated in a fully utilized condition when the operating personnel start work.
[0038] Furthermore, in the aforementioned conveyor arrangements, it is advantageous if at least two groups of longitudinal conveyor belts are provided, and the regulating device is adapted to arrange the products of the longitudinal conveyor belts of a first group on the transverse conveyor belt before the products of the longitudinal conveyor belts of a second group. It is often desirable for conveyor arrangements to be operated in such a way that the products are jointly collected from given regions, in particular a plurality of mutually spaced regions. It is only after that collecting operation is completed that the products are collected from other, mutually spaced regions. In that way, two or more groups of production regions can be defined, from which products are collected sequentially or in succession with respect to time. Ensuring constant or efficient utilization of the capacity of the processing station cannot be achieved precisely when using prior art conveyor arrangements and collection strategies. The conveyor arrangement according to the present invention now makes it possible for the first time also to implement such groupwise collection, and achieve constant or full utilization of the capacity of the processing station, by virtue of regulation of the longitudinal conveyor belts as a function of their point of entry, and the transverse belt advance. As in the case of joint collection and processing of all production regions, operation is based on the principle of feeding the production regions of a group to the transverse conveyor belt by way of the corresponding longitudinal conveyor belts in such a way that a closed front is formed using the full processing capacity, and after complete collection of the group, the next closed front of the next group is formed immediately behind the end of the preceding group, and so forth.
[0039] In this embodiment, it is particularly preferred that the regulating device is adapted to actuate first in each group the longitudinal conveyor belt most remote from the processing station. This provides that the groups achieve full levels of utilization of the capacity of the processing station, thereby avoiding longer lagging of the transverse conveyor belt at a low level of utilization of the potential capacity.
[0040] It is further preferred that the regulating device is adapted to actuate the longitudinal conveyor belts of the group, with the longitudinal conveyor belt most remote from the processing station as the last group. That has turned out to be advantageous, as otherwise there would be a major gap on the transverse conveyor belt, which would interfere with full utilization of the processing station, in the event one of the front longitudinal conveyor belts in a front group is collected, and following that, the last longitudinal conveyor belt is actuated, whereby the transverse conveyor belt remains product-free over a length corresponding to the distance between the front and last longitudinal conveyor belts. As an alternative thereto, the longitudinal conveyor belt most remote from the processing station in the last group could be activated, and that activation could occur at a predetermined period of time prior to termination of the activation of the last longitudinal conveyor belt of the previous group. In that case, the conveyor end of the previous group is predicted, and the most remote longitudinal conveyor belt can be started in such a way as to avoid a gap forming between the two groups.
[0041] Groupwise collection can be further optimized if the regulating device is adapted to determine the moment of stopping the last longitudinal conveyor belt of a group, and activating the first longitudinal conveyor belt of a subsequent group as a function of the spacing between the point of entry of the last longitudinal conveyor belt, and the first longitudinal conveyor belt on the transverse conveyor belt, and the transverse conveyor belt advance. With this feature, it is possible for the regulating device to leave between two groups a defined—positive or negative—spacing, by stopping and starting of the corresponding longitudinal conveyor belts being controlled in such a way that the groups specifically overlap or do not overlap, or are at a given spacing from each other.
[0042] In that case, it is particularly preferred that the regulating device is adapted to stop the longitudinal conveyor belts and the transverse conveyor belt when the last product of a group has been conveyed into the processing apparatus. In that way, the regulating device affords the possibility of implementing conversion at the processing station, in order to process products of different groups in different ways. In that respect, the last product of a group, or the first product of a following group, can be referred to as a criterion for initiating stopping of the transverse conveyor belt.
[0043] It is further preferred that the regulating device is adapted to determine the number of times the last products of the last longitudinal conveyor belt of the first group, and the first products of the first longitudinal conveyor belt of the second group, are deposited on the transverse conveyor belt in a joint mixed region. That produces a mixed region, which for example, contains products of different quality levels, and in the processing of which it is therefore necessary to accept that products of a higher quality level are sorted into a packaging which is classified with a lower quality level. With this feature, it is possible to achieve the advantage that the capacity of the processing station is fully utilized without interruption, and a fluent change takes place between the products in the first and second groups. In that case, the mixed region is treated in the processing station like the group with the products of the lower quality, and accordingly prior to or after the beginning of the mixed region, conversion of the processing mode is effected at the processing station, depending on whether the products are worse or better from one group to another in terms of their quality.
[0044] Finally, it is also preferred that, in the groupwise collection of the products, the regulating device is adapted to determine the number of times the longitudinal conveyor belts of the successive groups are started and stopped in such a way to form an intermediate space on the transverse conveyor belt between the products of the first group and the second group. In that way, a period of time for conversion of the processing station can be afforded without interrupting the conveyor procedure.
[0045] The conveyor arrangement according to one aspect of the invention can be designed so that the regulating device is adapted to activate so many longitudinal conveyor belts and/or to regulate the conveyor speed of the activated longitudinal conveyor belts in such a way that so many products are fed to each region of the transverse conveyor belt that a predetermined capacity of the processing station is achieved. In that way, full utilization of the capacity of the processing station is achieved by activation and/or speed regulation of the longitudinal conveyor belts, at any moment in time.
[0046] It is further preferred that the regulating device is adapted to allocate a fraction of the transverse conveyor belt width to each activated longitudinal conveyor belt, and to regulate the conveyor speed of each longitudinal conveyor belt in such a way that the respectively allocated width of the transverse conveyor belt is filled up with products by the respective longitudinal conveyor belt. That allocation means that each individual longitudinal conveyor belt can be regulated with respect to the conveyor capacity in such a way that the fraction of the transverse conveyor belt width that is allocated thereto is fully utilized. That makes it possible for longitudinal conveyor belts, which are to be emptied in a particularly rapid manner, to be provided with a large fraction of the transverse conveyor belt width, and therefore to preferably collect products therefrom. Also, longitudinal conveyor belts, which are collected over a longer period of time, provide only a small fraction of the transverse conveyor belt width and implement correspondingly slower collection.
[0047] In particular, in that respect, it is preferable that each longitudinal conveyor belt pre-stores a given number of products, and the regulating device is coupled to sensors for detecting the products still stored on each longitudinal conveyor belt, and is adapted to allocate to a longitudinal conveyor belt with few products, a smaller fraction of the transverse conveyor belt width than is allocated to a longitudinal conveyor belt with more products so that emptying of all longitudinal conveyor belts is finished or terminated at the same time, or in a time-displaced relationship by a given amount. This development of the invention provides that, besides full utilization of the capacity of the processing station from the beginning of the conveyor operation, which is possible with the conveyor arrangement according to the invention, the arrangement also provides for full utilization of the processing station up to the end of the conveyor operation. The sensors for detecting the products still stored on each longitudinal conveyor belt can, in a simple version, comprise travel sensors, which detect the conveyor belt advance of the longitudinal conveyor belt. An improved version is achieved by additionally ascertaining the product density on the longitudinal conveyor belt, for example by counting the products at the discharge. Particularly, if sensors for detecting the force due to the weight of the products of the above-described kind are installed, it is possible to infer the total eggs disposed on the longitudinal conveyor belt, from the measured weights.
[0048] A typical problem with prior conveyor arrangements is that the longitudinal conveyor belts have different amounts of products in readiness, and as a result, the longitudinal conveyor belts which have more products in readiness than others must still lag behind after termination of the conveyor operation of all other longitudinal conveyor belts. As a result, only a small amount of products is delivered onto the transverse conveyor belt from the individual longitudinal conveyor belt which is still continuing to convey products. Because of that small amount, the processing station cannot be utilized to its full capacity over a prolonged period of time. That causes time-intensive rectification at the processing station. With the development according to the present invention, it is possible for a large fraction of the transverse conveyor belt width to be allocated to such longitudinal conveyor belts, whereby the longitudinal conveyor belts with a larger number of products can be emptied as quickly as the other longitudinal conveyor belts. In that respect, the regulating device according to the present invention permits dynamic regulation of the respectively allocated transverse conveyor belt widths, that is to say, as soon as a greater transverse conveyor belt width is allocated to a longitudinal conveyor belt which is entirely filled, the transverse conveyor belt width of the other longitudinal conveyor belts is dynamically reduced to such a degree that in total the proportion attributed to the one longitudinal conveyor belt is attained. The aim of modified regulation of this kind is to operate the processing station at full capacity up to the end of the processing operation, and avoid the processing station lagging behind for isolated subsequently delivered products, at a low level of utilization of its capacity. For that purpose, it will typically be necessary to stop the longitudinal conveyor belts in a time-displaced relationship, as the longitudinal conveyor belts which are closest to the processing station have to be stopped last, and the most remote longitudinal conveyor belt has to be stopped first in order to achieve the desired abrupt termination of product accumulation on the transverse conveyor belt.
[0049] It is particularly preferred that the regulating device is coupled to a force sensor arranged at the exit region of the transverse force conveyor belt or a counting sensor of the above-described kind and is adapted to regulate the conveyor speed of the transverse conveyor belt as a function of the sensor signal.
[0050] Implementation of such a force sensor, in particular in conjunction with the conveyor arrangement according to one aspect of the present invention with a regulating device, permits reliable, comfortable and convenient regulation, as the variation in the conveyor speed of the transverse conveyor belt that is caused by virtue of the force sensor, is incorporated into the regulation action in the form of the transverse conveyor belt advance, and can thus be taken into consideration. In other words, for the first time it is possible with the conveyor arrangement according to one aspect of the invention to achieve full utilization of the processing station at any time in the conveyor operation, and to avoid repeated starting and stopping of the transverse conveyor belt, insofar as stepless regulation of the transverse conveyor belt is effected, and at the same time, the width of the transverse conveyor belt is completely filled up with products from the longitudinal conveyor belts at any time and at any location on the transverse conveyor belt.
[0051] Finally, a further development of the conveyor arrangement according to one aspect of the invention provides a display device, which is coupled to the regulating device to obtain from the regulating device signals for positionally resolved representation of the number of products on the transverse conveyor belt. The subject display device makes it possible for a user or operator of the conveyor arrangement to recognize full utilization of the individual conveyor belt lines and the processing station at a glance, and if necessary, modify and optimize the regulating procedures by means of parameter selection.
[0052] In accordance with a further aspect of the invention, there is proposed a conveyor arrangement comprising a transverse conveyor belt and a plurality of longitudinal conveyor belts leading onto the transverse conveyor belt, with at least one movable product guide device which is arranged above the transverse conveyor belt, and which is coupled to an actuator, wherein the actuator can move the product guide device into at least two positions at the support region of the transverse conveyor belt. The product guide device is laterally placed on the transverse conveyor belt in such a way that it guides the products on the transverse conveyor belt away from the entry region of at least one longitudinal conveyor belt. With this conveyor arrangement, it is possible to avoid a collision between products which are already on the transverse conveyor belt and products which are arriving from the longitudinal conveyor belt. The actuator can be actuated electrically, pneumatically, hydraulically or in another fashion. The product guide device can be a pivotably mounted plate.
[0053] In that embodiment, it is particularly preferred that there are a plurality of movable product guide devices, which are respectively arranged upstream of the entry regions of a plurality of longitudinal conveyor belts in the conveyor direction of the transverse conveyor belt. This feature permits variable product guidance in dependence on the conveyor state and the activated longitudinal conveyor belts.
[0054] It is further preferred that the actuator of each product guide device is coupled to a central control device, and is actuated as a function of the degree of filling of the transverse conveyor belt as calculated by the control device from supplied products and transverse belt advance upstream of the respective product guide device, in order to guide the products away from the entry region of the longitudinal conveyor belts to the degree permitted by the degree of filling. It is possible in that way to prevent the products from being damaged or laterally pushed away by the transverse conveyor belt. The product guide device can be so set that the maximum possible deflection is achieved, or only a fraction thereof, to achieve a deflection which is precisely sufficient to provide space on the transverse conveyor belt for the products which are still to be added thereto.
[0055] In addition, in the situation involving groupwise collection, it is preferable that the actuator of each product guide device is actuated in relation to the collected group. Pre-programmed actuator actuation can be effected in that way, and can be set in a group-dependent relationship when the respective group is collected.
[0056] The above-described conveyor arrangement according to one aspect of the invention is preferably used for conveying eggs on a longitudinal conveyor belt on which a plurality of mutually spaced, stationary intermediate storage regions is provided, which are so arranged that they receive the eggs laid in nest regions in cages arranged in a row along the longitudinal belt.
[0057] The above-described conveyor arrangement according to one aspect of the invention can further be used for conveying eggs on a transverse conveyor belt in order to convey eggs into an intermediate storage region, which is arranged in the conveyor direction upstream of an installation for further processing, such as a packaging installation.
[0058] The conveyor arrangement according to one aspect of the invention is preferably operated with a method of conveying eggs in the region of a henhouse comprising a plurality of cage units, comprising the steps:
a. temporarily storing or collecting the eggs laid in a first nest region of a cage or in a first cage on a first intermediate storage region of a static or stationary conveyor belt, b. measuring the cumulative force due to the weight of the eggs in the first intermediate storage region, c. conveyance of the longitudinal conveyor belt by a predetermined distance, such that a conveyor belt portion which is not occupied with eggs is provided as the first intermediate storage region, d. repetition of steps a to c up to a time at which further conveyance of the longitudinal conveyor belt by the predetermined distance would provide a conveyor belt portion already occupied with eggs due to an adjacent second intermediate storage region of a nest region of an adjacent second cage or a second cage as the first intermediate storage region, and e. further conveyance of the conveyor belt until the eggs deposited thereon have been transferred completely onto a second conveyor belt or into a storage means.
[0064] Another preferred method to operate the above-described conveyor arrangement comprises the steps:
a. conveying the eggs on a first conveyor apparatus into an intermediate storage region, b1. measuring the cumulative pressing force exerted by the eggs on a lateral boundary wall portion of the intermediate storage region, or b2. measuring the eggs standing up in the intermediate storage region, c. further conveying the eggs out of the intermediate storage region by means of a second conveyor apparatus, and d. regulating the conveyor speed of the first or second conveyor apparatus in dependence on the measured pressing force or the measured number of eggs standing up.
[0070] In accordance with a further aspect the present conveyor arrangement, the same can be operated with a method comprising the steps: conveying products on a transverse conveyor belt to a processing station, and delivering products by means of a plurality of longitudinal conveyor belts onto the transverse conveyor belt at various, mutually spaced locations, wherein the conveyor advance of the transverse conveyor belt is detected, and at the beginning of the conveyor operation, the longitudinal conveyor belts are set in operation in a time-displaced relationship as a function of the spacing between their point of entry onto the transverse conveyor belt and the processing station, and the conveyor advance of the transverse conveyor belt.
[0071] It is preferred that the first longitudinal conveyor belt most remote from the processing station is set in operation first, and a second conveyor belt arranged closer to the processing station is set in operation at a time at which the transverse conveyor belt has advanced to such an extent that the products conveyed by the first longitudinal conveyor belt have reached the entry region of the second longitudinal conveyor belt.
[0072] It is preferred that before the beginning of the conveyor operation, at least two groups of longitudinal conveyor belts are defined, and the longitudinal conveyor belts of a first group are activated first, and the longitudinal conveyor belts of a second group are activated subsequently.
[0073] It is preferred that in each group, the longitudinal conveyor belt furthest away from the processing station is activated first.
[0074] It is preferred that the longitudinal conveyor belts of the group with the longitudinal conveyor belt furthest away from the processing station are activated as the last group.
[0075] It is preferred that the time of stopping the last longitudinal conveyor belt of a group and activating the first longitudinal conveyor belt of a subsequent group is determined as a function of the spacing between the point of entry of the last longitudinal conveyor belt and the first longitudinal conveyor belt to the transverse conveyor belt, and the transverse conveyor belt advance.
[0076] It is preferred that the longitudinal conveyor belts and the transverse conveyor belt are stopped when the last product of a group has been conveyed into the processing apparatus.
[0077] It is preferred that the last product of the last longitudinal conveyor belt of the first group and the first products of the first longitudinal conveyor belt of the second group are deposited in a common mixed region on the transverse conveyor belt.
[0078] It is preferred that an intermediate space is provided on the transverse conveyor belt between the products of the first group of longitudinal conveyor belts and the products of the second group of longitudinal conveyor belts.
[0079] It is preferred that so many longitudinal conveyor belts are activated and/or the conveyor speed of the activated longitudinal conveyor belts is regulated, such that so many products are fed to each region of the transverse conveyor belt that a predetermined capacity of the processing station is attained.
[0080] It is preferred that a fraction of the transverse conveyor belt width is allocated to each activated longitudinal conveyor belt, and the conveyor speed of each longitudinal conveyor belt is so regulated that the respectively allocated width of the transverse conveyor belt is filled with products by the respective longitudinal conveyor belt.
[0081] It is preferred that each longitudinal conveyor belt pre-stores a given number of products, and the products stored on each longitudinal conveyor belt are detected by sensors, and a smaller fraction of the transverse conveyor belt width is allocated to a longitudinal conveyor belt with fewer products than the longitudinal conveyor belt with more products, in order to achieve termination of emptying of all longitudinal conveyor belts at the same time, or in time-displaced relationship by a given amount.
[0082] It is preferred that a force sensor arranged at the discharge region of the transverse conveyor belt measures the pressing force prevailing horizontally between the products at the discharge region, and the conveyor speed of the transverse conveyor belt is regulated in accordance with the force sensor signal.
[0083] It is preferred that the conveyor speed of the transverse conveyor belt is reduced if the measured pressing force exceeds a predetermined value.
[0084] It is preferred that the conveyor speed of the transverse conveyor belt is increased if the measured pressing force falls below a predetermined value.
[0085] It is preferred that the conveyor speed of the longitudinal conveyor belts and/or the transverse conveyor belt is steplessly or dynamically altered or varied.
[0086] It is preferred that a processing starting time is input, and activation and conveyor speed of the longitudinal conveyor belts and the transverse conveyor belt are started at a time ascertained as a function of the spacing between the longitudinal conveyor belt entry onto the transverse conveyor belt, and the transverse conveyor belt advance, in order to feed products to the processing station in a predetermined capacity at the start time of the processing station.
[0087] The invention can further be implemented using a computer program product for execution on a computer, which is so programmed that it performs the steps required for regulation of the conveyor arrangement according to the invention when it is executed on a computer.
[0088] These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0089] A preferred embodiment of the invention is described with reference to the Figures in which:
[0090] FIG. 1 shows a diagrammatic view of a conveyor arrangement having six henhouse buildings, longitudinal conveyor belts and a transverse conveyor belt,
[0091] FIG. 1 a shows a view on an enlarged scale of an individual henhouse building as shown in FIG. 1 ,
[0092] FIG. 2 shows a diagrammatic plan view of the region of a row of henhouses with aviaries arranged in a mutually juxtaposed relationship,
[0093] FIG. 3 shows a side view in cross section of the region of the longitudinal conveyor belt and the region of rolling out of a nest of an aviary,
[0094] FIG. 4 a shows a first embodiment of the entry region of a transverse conveyor belt into a packer with a force pickup device,
[0095] FIG. 4 b shows a second embodiment as shown in FIG. 4 a,
[0096] FIG. 4 c shows a third embodiment as shown in FIG. 4 a,
[0097] FIG. 5 shows a side view of a variant of the embodiments of FIGS. 4 b and 4 c,
[0098] FIG. 6 shows a plan view of a fourth embodiment as shown in FIG. 4 a with a transverse conveyor belt regulator,
[0099] FIG. 7 shows a diagrammatic view of a visualization of the conveyor advance of a transverse conveyor belt in a start-up phase of the conveyor operation,
[0100] FIG. 8 shows a portion from FIG. 7 at a time of termination of the conveyor operation,
[0101] FIG. 9 shows a diagrammatic view of a further embodiment of the conveyor arrangement according to the invention with two transverse conveyor belts,
[0102] FIG. 10 shows a diagrammatic view of the visualization of the conveyor belt advance of the arrangement shown in FIG. 9 , and
[0103] FIG. 11 shows a diagrammatic plan view of a portion of a transverse conveyor belt with five longitudinal conveyor belts entering the same and four controllable product guide devices.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0104] For purposes of description herein, the terms “upper”, “lower”, “right”, “left”, “rear”, “front”, “vertical”, “horizontal” and derivatives thereof shall relate to the invention as oriented in FIGS. 1 and 1 a . However, it is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
[0105] FIG. 1 shows an egg farm with six henhouse buildings 1 - 6 , each of which has four double rows 1 a - 1 d with a plurality of tiers of aviaries or cage systems arranged in rows one behind the other.
[0106] The henhouse buildings 1 - 6 are arranged in mutually juxtaposed relationship in such a way that a transverse conveyor belt 10 can pass in a straight line at the end of the henhouse buildings. The transverse conveyor belt 10 is oriented at a right angle to the rows of aviaries 1 a - 1 d in the region of the henhouse buildings.
[0107] As can be clearly seen in particular from FIG. 1 a , longitudinal conveyor belts 11 a - 11 d and 12 a - 12 d are arranged in a mutually parallel relationship, and are respectively disposed at each side of the rows of aviaries 1 a - 1 d . Each tier of the rows of aviaries has its own longitudinal conveyor belts so that, for the five tiers of the rows of aviaries as shown in FIGS. 1 and 1 a , there are total of ten longitudinal conveyor belts for each row of aviaries, and forty longitudinal conveyor belts for each henhouse building. The longitudinal conveyor belts 11 a - 11 d and 12 a - 12 d of the individual rows of aviaries communicate alternatively with an elevator (not shown) at the end of each row of aviaries, which lifts the eggs out of the ten longitudinal conveyor belts of a row of aviaries onto the transverse conveyor belt 10 , or alternatively, the transverse conveyor belt 10 is displaced in height and the five tiers of the rows of aviaries are collected sequentially or in succession with respect to time.
[0108] The transverse conveyor belt 10 conveys from right to left in FIGS. 1 and 1 a , and opens into a packaging station 20 in which the eggs are packaged.
[0109] A central control and regulating unit 30 is connected to peripheral control and regulating units in each henhouse building, and carries out the control and regulating procedures according to the invention for the longitudinal conveyor belts 11 a - 11 d and 12 a - 12 d and the transverse conveyor belt 10 .
[0110] A central farm control system 40 permits a selection of parameters, as well as visualization of the egg collection procedure and the degree of utilization of the individual conveyor belts.
[0111] FIG. 2 shows a plan view of a portion of a double row of aviaries with four aviaries in an adjoining relationship to the left and the right, respectively, and two further partially illustrated aviaries. An individual aviary extends over a length L 1 of the longitudinal conveyor belts 11 a , 12 a. A fraction L 2 of the length L 1 is occupied by a nest region L 3 in the aviary. In the region of the length L 2 , over 90 percent of the eggs are laid by the hens in the aviary, so that the longitudinal conveyor belt 11 a is filled in the region L 2 in the stopped or static condition in a relatively short period of time during the laying period.
[0112] Two nest regions 13 of adjacent aviaries are in a directly adjoining relationship, as can be seen from FIG. 2 . Therefore, when the longitudinal conveyor belt in the region of the nest is filled with eggs, the longitudinal conveyor belts 11 a , 12 a must be advanced at least by double the length L 2 in order to move a portion of the conveyor belt which is empty into the nest region 13 . As the length L 2 in the present example is a quarter of L 1 , that advance movement on the part of each longitudinal conveyor belt 11 a , 12 a can be effected three times. On the fourth occasion, the filled region of each longitudinal conveyor belt 11 a , 12 a would be conveyed out of the nest region 13 into the nest region 14 . As in that situation, the longitudinal conveyor belt is therefore full, and the longitudinal conveyor belt must be continuously operated after it has advanced three times by the length 2×L 2 until all eggs are conveyed from the longitudinal conveyor belt 11 a , 12 a onto the transverse conveyor belt 10 .
[0113] FIG. 3 shows an arrangement of the force sensor according to the invention, which is adapted to control the advance of the longitudinal conveyor belts 11 a - 11 d and 12 a - 12 d as shown as a function of the number of eggs which have rolled from the nest region 13 onto the longitudinal conveyor belt. The eggs roll on an inclined plane 15 out of the nest region 13 to the longitudinal conveyor belt 11 a . The upper run of the longitudinal conveyor belt 11 a runs above a weighing pan 16 which is coupled to a force sensor 18 by means of two L-shaped members 17 a, 17 b. The force sensor 18 is fixedly connected to the frame of the aviaries by means of a U-shaped member 19 . The force sensor 18 ascertains the weight of the eggs arranged on an intermediate storage region 16 ′ on the conveyor belt 11 a above the weighing pan 16 .
[0114] The force sensor 18 can be in the form of a pressure sensor, but preferably it is in the form of a flexural beam sensor acting at one side, which represents a robust structure, which at the same time is also reliable.
[0115] The procedure involved in the conveyor method of the arrangement shown in FIG. 3 is as follows. The eggs roll on the inclined plane 15 to a stop wire outside the aviary frame (not shown). The stop wire slows down the eggs and thus prevents those eggs from colliding with eggs which are already lying on the longitudinal conveyor belt 11 a , and it is cyclically lifted to allow the eggs to pass through onto the conveyor belt 11 a at a low speed. The greater the number of eggs on the conveyor belt 11 a in the region above the weighing pan 16 , the correspondingly greater weight is detected by the force sensor 18 . Upon the attainment of a given limit value, which on the basis of an average egg weight, indicates complete filling of the longitudinal conveyor belt 11 a in the region of the nest, the longitudinal conveyor belt is advanced by double the magnitude of the nest length in order to move an empty region of the longitudinal conveyor belt 11 a into the nest region 13 . That procedure is repeated three times, and on the fourth occasion, complete collection of the eggs from the longitudinal conveyor belt 11 a is implemented by the longitudinal conveyor belt being operated until it has covered at least a total lengthwise extent of the conveyor belt (that is to say half the length of the conveyor belt) and all eggs have been conveyed onto the transverse conveyor belt 10 .
[0116] FIG. 4 a shows another embodiment of the force sensor according to the invention in the entry region to a packaging station 20 . The eggs are passed to the packaging station 20 by one or more transverse conveyor belts 10 by way of a funnel table 10 ′, and are brought together to the width of the packaging station 20 on the table by means of wall guide elements 21 . That provides for compacting the distribution of the eggs in an intermediate storage region 21 ′ between the two wall guide elements 21 . In the entry region of the packaging station 20 , the eggs must be introduced into guide passages 22 a, 22 b, etc. In those regions, a build-up and congestion or accumulation of eggs may occur by virtue of transversely disposed eggs, which can lead to further compacting of the egg distribution. That compacting effect can mean that the horizontal pressure between the eggs in the entry region upstream of the packaging station can become so great that hair cracks are produced in the eggshells, or the eggs are completely destroyed.
[0117] In order to detect such a situation before damage occurs, arranged laterally in the entry region are two pressure sensors 23 a, 23 b coupled to two half-round pressure pickup plates 24 a , 24 b. The pressure pickup plates 24 a and 24 b project into the flow of eggs and detect a superposed, horizontally acting force component in transverse relationship with the conveyor direction and in opposite relationship to the conveyor direction. In relation to the level of the force detected by the force sensors 23 a, 24 b, the conveyor speed of the transverse conveyor belt 10 is regulated. If the measured force rises, the transverse conveyor belt speed is reduced, while if the force falls, the transverse conveyor belt speed is increased.
[0118] FIG. 4 b shows an alternative to the arrangement of FIG. 4 a. In the FIG. 4 b arrangement, the force sensors 23 a, 24 b are replaced with light barrier devices 25 a, 25 b which pass transversely over the entry region of the packaging station 20 . The light barrier devices are so oriented that they measure over the eggs which are lying flat on the bottom surface of the packaging station, as can be seen from FIG. 5 . As soon as an egg stands up on end, or the eggs come to lie one upon the other, they break the light beam of the light barrier device 25 a, 25 b. The number of such detected eggs is a measurement which reflects the horizontal pressure between the eggs in the entry region, and can once again serve to regulate the transverse belt conveyor speed, as described hereinbefore.
[0119] FIG. 4 c shows a further variant of the embodiment with light barrier devices as shown in FIG. 4 b. In FIG. 4 c, there are a total of four light barrier elements 26 a - 26 d which monitor the entry region of the packaging station 20 over the area thereof, and thus ensure more precise detection of eggs which are standing up or which are arranged one upon the other.
[0120] FIG. 6 shows a variant of the embodiment of FIG. 4 a with force sensors. The transverse conveyor belt 110 conveys the eggs by way of a funnel table 110 ′ into a reaction region 122 in front of a packaging station 120 . Side wall elements 121 a, 121 b guide the eggs together and compress the distribution thereof. Arranged at each of the side wall elements 121 a, 121 b is a respective pressure pickup 123 a, 123 b coupled to a half-round deflection and pressure pickup plate 124 a, 124 b. The pressure pickup plate 124 a, 124 b is respectively pivotably mounted in a hinge mounting 125 a, 125 b arranged on the side facing towards the conveyor direction and as a result can freely movably transmit a pressing force exerted by the eggs to the pressure pickup 123 a, 123 b.
[0121] Placed centrally in the reaction region 122 , in the form of an island arrangement, are two further pressure sensors 123 c, 123 d which are again supported by means of two half-round pressure pickup plates 124 c, 124 d mounted pivotably in a common pivot mounting 125 c in order to detect the horizontal egg pressure in the central region. The use of four pressure pickups at mutually spaced locations with a differing measurement direction ensures that even local compression phenomena, indicative of egg distribution with unacceptably high horizontal forces, are detected, and the transverse belt conveyor speed can be appropriately regulated.
[0122] The pressure pickups 123 a - 123 d are connected to a central transverse conveyor belt control 126 , coupled in turn to a frequency converter 127 for actuating the drive motor 128 for transverse belt conveyance.
[0123] A timing device 129 is also connected to the central control unit 126 and indicates the advance of the transverse conveyor belt.
[0124] FIG. 7 shows an example of a display screen that provides visualization of the full utilization and advance of the transverse conveyor belt 210 . The transverse conveyor belt 210 is divided into a plurality of transverse strips, each respective one of each represents a transverse conveyor belt length of 1 m.
[0125] Along the transverse conveyor belt 210 , six longitudinal conveyor belts 211 a - 211 f communicate at spaced locations with the transverse conveyor belt 210 . The longitudinal conveyor belts are illustrated by box symbols 211 a - 211 f in which are shown parameters relating to the conveyor properties of the longitudinal conveyor belt.
[0126] The left-hand end the transverse conveyor belt 210 leads to a packaging station 220 .
[0127] FIG. 7 shows a conveyor arrangement state in which the collection operation from the longitudinal conveyor belts 211 was begun a short time ago. That is represented by black bars in the transverse conveyor belt regions downstream in the conveyor direction of the point of entry of the longitudinal conveyor belt 211 f . The black bar region 212 symbolically represents the eggs deposited on the transverse conveyor belt 210 . In addition, a hatched rectangular region in the region of the entry of the longitudinal conveyor belt 211 f symbolically represents the transverse conveyor belt width allocated to the longitudinal conveyor belt 211 f.
[0128] FIG. 8 shows the arrangement of FIG. 7 at a later time in the operation of transverse conveyor 123 . In region 213 f filled to a reference value, the transverse conveyor belt picks up eggs to a transverse conveyor belt capacity of 80 percent, which includes a safety margin in relation to utilization at full capacity. In the region 214 , it is possible to see the discharge of the collection of the first group of eggs, which can be seen by virtue of the fact that the width of the transverse conveyor belt is utilized in a diagonally decreasing fashion. The first group, in the direction of conveyor travel, is followed by a second group of eggs, which is put onto the transverse conveyor belt by activation of the longitudinal conveyor belt 211 e . A gap 216 is left between the group 213 , 214 , and the group 215 , wherein the gap allows a short period of time for conversion of the packaging station 220 .
[0129] FIG. 9 shows a diagrammatic plan view of a conveyor arrangement having two transverse conveyor belts 310 , 312 , and FIG. 10 shows a diagrammatic view of a display screen that provides visualization of that conveyor arrangement. As can be seen, arranged at each transverse conveyor belt 310 , 312 are a plurality of longitudinal conveyor belts 311 a - 311 e , 313 a - 313 e, which lead onto the transverse conveyor belt 310 and 312 , respectively, at spaced locations. Each longitudinal conveyor belt 311 a - 311 e , 313 a - 313 e has its own local control, which actuates the longitudinal conveyor belt as a function of a weighing sensor, as shown in FIG. 3 , and at the command of a higher order central control system 330 , which causes total emptying of the longitudinal conveyor belt onto the corresponding transverse conveyor belt.
[0130] Both transverse conveyor belts 310 , 312 open to a packaging station 320 .
[0131] As can be seen from FIG. 10 , the eggs collected on the transverse conveyor belt are placed thereon in a locally displaced relationship from four activated longitudinal conveyors 331 c - 331 f, and are fed in the form of an interconnected block corresponding to the capacity of the packaging station 320 , to the packaging station 320 . On the transverse conveyor belt 312 , only the longitudinal conveyor belts 313 d - 331 f are active, and it is only after a further advance of the transverse conveyor belt 312 that the further longitudinal conveyor belts 313 a - 313 f are switched on.
[0132] FIG. 11 shows a portion of a transverse conveyor belt 410 with a plurality of longitudinal conveyor belts 411 a - 411 e which connect with the transverse conveyor belt 410 at locations of entry of which are spaced from each other in the conveyor direction. A plurality of eggs, which are symbolically represented by circles on the conveyor belt, are conveyed on the transverse conveyor belt in the conveyor direction shown by the arrow.
[0133] As will be seen, the products pass into the illustrated portion of the transverse conveyor belt at the right-hand edge, as viewed in the direction of the transverse conveyor belt, and would therefore impede the feed of further eggs from the longitudinal conveyor belts 411 a - 411 e , as they would first have to press the eggs, which are already on the transverse conveyor belt, in the direction of the left-hand edge, as seen in the direction of conveying movement of the transverse conveyor belt, with a considerable horizontal pressure. In that situation, the eggs can suffer damage.
[0134] Arranged upstream of longitudinal conveyor belt 411 e in the conveyor direction of transverse conveyor belt 410 is an egg guide device 420 a, which includes an egg guide plate 421 a mounted pivotably in a laterally and stationarily supported pivot mounting 422 a. The egg guide plate 421 a can be pivoted into or out of the region above the transverse conveyor belt 410 by means of an actuator, which in this case, is an electrical linear drive 423 a with position feedback signaling.
[0135] Arranged in a similar fashion and of a similar structure, between the longitudinal conveyor belts 411 d and 411 e , between the longitudinal conveyor belts 411 c and 411 d and between the longitudinal conveyor belts 411 b and 411 c , are respective egg guide devices 420 b - 420 d, which are of the same structure as the egg guide device 420 a.
[0136] In the illustrated conveyor condition, additional eggs are conveyed from the longitudinal conveyor belts 411 a - 411 e to add to the eggs which are already on the transverse conveyor belt 410 . In order to avoid damage to the additional eggs which are being supplied thereto, or the eggs which are already on the transverse conveyor belt, in that conveyor condition, the egg guide device 420 a is pivoted into the region above the transverse conveyor belt 410 to such an extent that the eggs are deflected from the right-hand side to the left-hand side, so that space is provided for the eggs additionally arriving from the longitudinal conveyor belts 411 a - 411 e . The egg guide devices 420 b and 420 c are not pivoted out.
[0137] The egg guide device 420 d is pivoted out by a lesser amount than the egg guide device 420 a in order to guide the eggs which are additionally arriving from the longitudinal conveyor belts 411 d , 411 e away from the right-hand edge of the transverse conveyor belt, and thus provide space for the eggs which are being added from the longitudinal conveyor belts 411 a , 411 b , without guiding the entire flow of eggs on the transverse conveyor belt excessively far in the direction of the left-hand edge of the transverse conveyor belt, as that would cause damage to the eggs which are already on the transverse conveyor belt 410 .
[0138] The electrical linear drives 423 a - 423 d and the position feedback signaling units of those drives of the egg guide devices 420 a - 420 d are coupled to the central control system, and are actuated as a function of the number of eggs already on the transverse conveyor belt, their arrangement, and possibly the conveyor rate of the longitudinal conveyor belts which are additionally feeding eggs, and are extended to such an extent that neither damage to the deflected eggs nor damage to the eggs which are being added can occur.
[0139] The conveyor method according to the invention operates as follows.
[0140] At a time about three hours after the beginning of laying, the longitudinal conveyor belt 311 f which is most remote from the packaging station is activated and conveys the eggs onto the transverse conveyor belt 310 . The transverse conveyor belt 310 is also activated and conveys the eggs in the direction of the packaging station 320 . As soon as the eggs moved onto the transverse conveyor belt 310 by the longitudinal conveyor belt 311 f reach the point of entry of the longitudinal conveyor belt 311 e , the longitudinal conveyor belt 311 e is also activated and conveys the eggs onto the transverse conveyor belt 310 . In that way, the eggs on the two longitudinal conveyor belts 311 e , 311 f are added to give a total transverse conveyor belt width. As soon as that region reaches the point of entry of the longitudinal conveyor belt 311 d , longitudinal conveyor belt 311 d is also activated, and so forth, until activation of the longitudinal conveyor belt 311 a occurs. In that way, full utilization of capacity is achieved over the full width of the transverse conveyor belt, and at the beginning of the work done by the packers at the packaging station 320 , the transverse conveyor belt is completely filled, and the eggs are positioned just upstream of the packaging station 320 .
[0141] The eggs supplied by each longitudinal conveyor belt are counted in the region of the mouth opening of the respective longitudinal conveyor belts to provide a check concerning the laying output of the respective henhouse or the respective rows of aviaries. Furthermore, the egg counting operation makes it possible to precisely determine the eggs disposed on the transverse conveyor belt. As soon as it is recognized that a longitudinal conveyor belt contains a very high number of eggs, for example by a high number of eggs already being counted with a short advance movement of the longitudinal conveyor belt, a greater transverse conveyor belt width is allocated to that longitudinal conveyor belt, and a correspondingly reduced width is allocated to the other longitudinal conveyor belts. This ensures that even the longitudinal conveyor belt which is filled to an above-average extent is emptied within a period of time in which the other longitudinal conveyor belts are also emptied. This dynamic regulation can possibly be further adapted if other longitudinal conveyor belts emerge as being emptied belatedly or prematurely.
[0142] The method according to the invention is the first to make it possible to provide for automatic regulation and full utilization of the capacity of the packaging station as a function of the eggs supplied by the individual longitudinal conveyor belts and the individual spacing thereof from the packaging station, as well as the respective currently prevailing transverse conveyor belt advance.
[0143] In the foregoing description, it will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed herein. Such modifications are to be considered as included in the following claims, unless these claims by their language expressly state otherwise.
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A conveyor for shock-sensitive products includes a conveyor member with at least one intermediate storage region adapted to receive a predetermined number of the products placed thereon when the conveyor is a static condition for temporary intermediate storage. A force measuring member determines the weight force of the products in the intermediate storage region. A control member, adapted to increase and decrease the rate of feed of the shock-sensitive products in the conveyor member, processes the weight force detected by the force measuring member as an input parameter, and increases or reduces the rate of feed of the products toward and away from the intermediate storage region as a function of the weight force.
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This application is a continuation application of divisional application Ser. No. 10/768,836, filed Jan. 29, 2004, issued as U.S. Pat. No. 7,086,147B2, which divisional application is based on parent application Ser. No. 09/845,448, filed Apr. 30, 2001, issued as U.S. Pat. No. 6,686,664.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods and structures for attaching a semiconductor chip or chip carrier to a substrate and, more particularly, to methods and structures for attaching a semiconductor chip or chip carrier to a substrate using solder ball technology.
2. Background and Related Art
In the fabrication of electronic devices as, for example, during ball attach or card attach, low melt C4 (controlled collapsed chip connection) solder balls on a chip carrier will reach their melting temperature and become liquid. Typically, for solder with a high tin content, the volume expansion associated with this phase change can range between 3 and 6%. If the C4 solder balls have been encapsulated prior to this volume change, as is typically the case, the volume expansion is constrained and the resulting pressure may result in the squeezing of this expanding volume of liquid into voids present in the surrounding underfill and its associated interfaces. This volume expansion of solder may also result in opening any weak interfaces, like underfill to chip passivation (for example polyimide) or underfill to solder mask interfaces. It is clear that the effect of such action could result in device failure.
SUMMARY OF THE INVENTION
In accordance with the present invention, structures are provided on the chip carrier to relieve pressure created by volume expanding solder upon heating and reflow. The structures are formed directly beneath the solder balls or bumps. The pressure relief structure may be in the form of microchannels or vias, an air cushioned diaphragm, or porous or compressible medium, like foam. The various structures act in a manner to accept or accommodate the expanding or excess volume of solder created during melting to thereby minimize or avoid the creation of pressure that may affect the region adjoining or surrounding the solder balls and the various material interfaces.
Accordingly, it is an object of the present invention to provide improved methods of making connections in electronic devices, to enhance overall reliability of the product.
It is another object of the present invention to provide structures which act to accommodate expanding solder when it changed to the liquid phase.
It is yet another object of the present invention to provide a method of attaching enclosed solder balls to connection pads by providing structures that accommodate expanding solder upon reflow.
It is a further object of the present invention to provide structures that relieve internal pressures in an enclosed electronic packaging environment caused by the expansion of solder when going from the solid to liquid phase.
It is yet a further object of the present invention to provide methods and structures that relieve pressure from solder reflow to thereby prevent damage to material interfaces in electronic devices.
These foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings, wherein like reference members represent like parts of the invention.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a cross-section of a typical Prior Art arrangement wherein a semiconductor chip is positioned for electrical connection to a substrate through an array of solder balls.
FIG. 2A shows an enlarged section of the arrangement shown in FIG. 1 with one form of structure used to release pressure on reflow of solder balls.
FIG. 2B shows an enlarged section of the arrangement shown in FIG. 1 with a further structure used to release pressure on reflow of solder balls.
FIG. 3 shows another enlarged section of the arrangement shown in FIG. 1 with an air-cushioned form of structure used to relieve pressure on reflow of solder balls.
FIG. 4 shows yet another enlarged section of the arrangement shown in FIG. 1 with another air-cushioned form of structure used to relieve pressure on reflow of solder balls.
FIG. 5 shows still yet another enlarged section of the arrangement shown in FIG. 1 with a compressible form of structure used to relieve pressure on reflow of solder balls.
FIG. 6 shows a further enlarged section of the arrangement shown in FIG. 1 with a further porous form of structure used to relieve pressure on reflow of solder balls.
DETAILED DESCRIPTION
With reference to FIG. 1 , there is shown a conventional arrangement of semiconductor chip and substrate. Substrate 3 may be a PCB type of substrate or a ceramic substrate, for example. Substrate 3 may also be a single chip module or a multi chip module (MCM) which is, in turn, attached to a substrate, such as a PCB. Chip 1 is shown positioned on substrate 3 with C4 solder balls or bumps 5 , for example, positioned therebetween. Solder balls 5 may, in fact, not be ball shape but may be shaped like bumps or be, very generally, globular in shape. FIG. 1 shows the balls 5 somewhat elongated in shape but slightly truncated at their ends by conductive pads 7 and 9 . Thus, the terms “solder balls” or “solder bumps” should not be taken to be limiting in shape but taken to be more as a mass of solder. In this regard, it is clear that connection is not necessarily limited to a C4-type or a flip chip solder connection but may, for example, be a BGA solder interconnect. Typically, solder balls 5 are first attached to conductive pads 7 on substrate 3 . Pads 7 may, for example, be copper pads. Chip 1 is then aligned so that its copper pads 9 , or other bump limiting metallurgy (BLM) structures, align with solder balls 5 .
As further shown in FIG. 1 , a layer of insulating material 11 surrounds and encapsulates solder balls 5 . Typically, the chip and substrate pads are aligned to solder balls 5 and then the arrangement heated to reflow the solder to make the connection. After connection is made, an underfill is then dispensed between chip and substrate to provide encapsulation of the solder connections and support therefor.
Whatever technique is used to make connections and encapsulate same, it is clear that when encapsulated there is little room for expansion of the solder balls or connections on subsequent single or multiple reflow. Subsequent reflow may occur, for example, when there is subsequent attachment to a PCB, where substrate 3 is a single or MCM, or subsequent attachment to a card. It can also occur during preconditioning. This problem is particularly severe for low melt single alloy solders. Typically, the volume expansion associated with high tin content solders in going to the liquid phase is 3 to 6%. However, the problem may exist for any of a variety of solder alloys that exhibit high volume expansion (e.g. >3%) on melting and that will encounter additional reflow (melt) temperatures during assembly or preconditioning of the package.
With such volume expansion in an encapsulated environment, the phase change instantaneously produces pressure that may result in the squeezing of the excess volume into voids present in the surrounding underfill or spacer, or produce a hydraulic force acting on the semiconductor chip thus opening or delaminating any weak interfaces, such as, the underfill-polyimide and underfill-solder mask interfaces. In addition, solder bridging, solder migration to interfaces and solder depletion within joints may occur. In this regard, it should be understood that the problems caused by solder volume expansion on reflow also exist with second and subsequent levels of solder interconnects, such as, BGA solder joints that have been underfilled or encapsulated. Accordingly, the teachings of the present invention to solve such problems are equally applicable to second and subsequent levels of packaging. The teachings help in mitigating the above related problems and provides for improving reliability of the electronic product.
In accordance with the present invention, several structural arrangements are provided to relieve pressure created by volume expansion of solder during reflow. FIG. 2A is enlarged partial section showing one of the solder balls of FIG. 1 with such partial section showing one such structural arrangement for relieving pressure during reflow. Microchannel, cavity or via 13 is shown beneath solder ball 5 to accommodate expanding solder volume during reflow. Connection to other circuitry here is through top surface metallurgy connected to pad 7 . In this regard, each of the solder balls in the solder ball array is provided its own independent microchannel or via to facilitate expansion. These microchannels or vias may be, for example, laser drilled by laser ablation through pads 7 (forming hole 8 ) and into the substrate 3 prior to mounting solder balls and chip to the substrate.
Representative dimensions for a 5% volume expansion of C4 solder balls might be A=140 μm, B=100 μm, C=45 μm and D=25 μm. Such dimensions would typically approximate the maximum volume of the microchannel that is needed to accommodate 5% volume expansion of solder. It should be understood, however, that, in general, the microchannel volume need not necessarily be large enough to accommodate the total volume expansion of the solder but rather the microchannel volume may be optimized to be large enough to sufficiently relieve pressure and limit stress build-up so that it is below the interfacial adhesion strength of the underfill. This, in turn, will depend on the type of underfill and passivation on the die and the choice of solder mask material on the laminate.
Microchannel or via 13 , in FIG. 2A , has a non-wettable surface 15 such that during reflow, the excess volume of solder would be forced into microchannel 13 thus relieving the pressure by accommodating the excess volume without affecting the adjoining regions. Then, during cooling the surface tension of the solder would force the solder back up onto copper pad 7 thus regaining its original ball-like shape. It should be understood that the Figures are not to scale and are only generally illustrative of the shapes and sizes and are merely used to facilitate a description and understanding of the invention.
FIG. 2B shows a pressure relief structure similar that shown in FIG. 2A but rather than employ a single microchannel or via, multiple microchannels are employed under each solder ball, such as shown at 14 and 16 . As in FIG. 2A , holes in pad 7 may be laser ablated and then the microchannels or vias 14 and 16 either ablated or etched into substrate 3 . Similar to FIG. 2A , the surfaces of microchannels or vias 14 and 16 may be non-wettable.
Employment of multiple microchannels or vias, as shown in FIG. 2B , would be particularly useful for BGA solder joints, such as, those employed in MCM-L (multi chip module-laminate) and CSP (chip size package) applications that have large contact surface areas. By using multiple microchannels, the microchannel depths may be reduced to achieve the same total volume. Shorter microchannel depths have the advantage of shorter return paths for solder upon solidification. A particularly advantageous shape for the microchannels would be conical, as shown in FIG. 2B , with E>D for each hole. Although two microchannels or vias 14 and 16 are shown in FIG. 2B , it is clear that more than two holes could be employed. Typically, anywhere from 2 to 6 somewhat evenly spaced holes through pad 7 would work well although the number will be somewhat dependent upon the area of the pad surface. It should also be noted, that the single hole 13 in FIG. 2A could also be conical in shape with the larger opening running through pads 7 , similar to FIG. 2B .
FIG. 3 shows another structural arrangement for accommodating solder volume expansion during reflow. In FIG. 3 , via or cavity 17 is plated with a layer 19 of conductive material, such as, copper. The plated via 17 , shown in contact with pad 7 , is used to make connection to other circuitry. Electrical connection can also be made directly to pad 7 from the surface. In this structural arrangement, pad 7 also acts as an air-cushioned diaphragm which functions to accommodate expanding volume of solder into via 17 during reflow. In this regard, pad 7 is sufficiently thin and elastic so as to flex without rupture in response to the expanding volume of solder during reflow and, then, upon cooling return to its original state, as shown.
FIG. 4 shows a further air-cushioned diaphragm arrangement for accommodating excess volume of solder during reflow. In this arrangement, a flexible insulating layer 21 , such as polyimide, is used as a diaphragm over cavity 23 . A hole or via 25 formed in pad 7 exposes solder ball 5 to layer 21 . During reflow of solder ball 5 , excess volume of solder acts to depress layer 21 downwardly into cavity 23 to accommodate the expanding volume. During cooling, the volume expanded into the cavity via layer 21 is contracted and the air-cushioned diaphragm returns to its original state, as shown.
FIG. 5 shows yet another structural arrangement for accommodating solder volume expansion during reflow. In FIG. 5 , a somewhat porous, deformable layer 27 is exposed to solder ball 5 by way of a hole or aperture 29 . Layer 27 has a top surface that is closed and continuous (non-permeable to solder) and compliant. Upon application of heat to reflow solder ball 5 , excess solder caused by volume expansion during the liquid phase is forced downwardly through hole 29 causing deformable layer 27 to compress to relieve the resultant pressure. The liquid solder on reflow does not enter into the pores or voids of layer 27 since its top surface is non-permeable. Since compression is local to each cell, each cell is closed off from the others. In addition to having the top surface of layer 27 non-permeable, a thin, flexible, non-permeable membrane may also be formed on its surface. Upon cooling, the liquid solder is drawn back up through hole 29 onto pad 7 to its original position, as shown. This is a result of both surface tension and pressure from the deformable layer. Typical materials that may be used for layer 27 are RO2800 Rogers material with a non-permeable membrane, like polyimide, adhered to the top surface such that it acts as a closed-cell -material. Cellular silicone can also be converted to a closed-cell structure through adhesion of polyimide to its surface. Thicknesses for layer 27 may range from 75 μm to 100 μm.
FIG. 6 shows yet a further structural arrangement for accommodating solder volume expansion during reflow. In FIG. 6 , a porous, rigid layer 31 is employed, in contrast to the deformable layer 27 in FIG. 5 . In the structural arrangement of FIG. 6 , when solder ball 5 is subjected to heat to reflow the solder, the volume expansion of the solder in the liquid phase is accommodated by being absorbed into the pores or voids of layer 31 . In this regard, the surface of layer 31 is open, i.e., the voids are accessible at the surface portion of the layer exposed to hole 29 . Thus, the voids in regard to layer 31 act as pressure relief reservoirs. Layer 31 may be made, for example, of porous ceramic material with non-wettable voids. Again, upon cooling the liquid solder is drawn up through hole 29 to reform on pad 7 , as shown.
To ensure that the porous area under solder ball 5 is isolated from the porous areas under adjacent solder balls, isolation trench or region 33 may be formed. Isolation region 33 may be made by forming a trench in rigid layer 31 around the region beneath solder ball 5 . The trench may then be backfilled with an isolating material, such as, polyimide or an oxide. The trench may be etched or laser profiled through layer 31 to substrate 3 . Isolation region 33 prevents unwanted migration of the solder, absorbed during reflow, from interacting with the solder absorbed during reflow of an adjacent site. Rigid layer 31 may be made of a conventional ceramic material fabricated to exhibit voids. Layer 31 may be 75 μm to 100 μm thick.
Rather than form isolation region 33 in the porous rigid layer 31 , the substrate, itself, may be used to form an isolation region. This may be achieved by masking a region of substrate 3 around the site of the solder ball that is to act as the isolation region, and then etching back the substrate inside the region. Thereafter the etched region is backfilled with the porous, rigid material.
It will be understood from the foregoing description that various modifications and changes may be made in the preferred embodiment of the present invention without departing from its true spirit. It is intended that this description is for purposes of illustration only and should not be construed in a limiting sense. The scope of this invention should be limited only by the language of the following claims.
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Solder balls, such as, low melt C4 solder balls undergo volume expansion during reflow. Where the solder balls are encapsulated, expansion pressure can cause damage to device integrity. A volume expansion region in the semiconductor chip substrate beneath each of the solder balls accommodates volume expansion. Air-cushioned diaphgrams, deformable materials and non-wettable surfaces may be used to permit return of the solder during cooling to its original site. A porous medium with voids sufficient to accommodate expansion may also be used.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to an electronic compressed air system for vehicles.
[0002] WO 98/47751 A1 describes a pneumatic vehicle brake system provided with a compressor, at least one air-load circuit, such as service-brake circuits, a parking-brake circuit, a low-pressure auxiliary circuit and a high-pressure circuit, wherein the circuits are provided with compressed air reservoirs and demand valves. Between the compressor and the at least one load circuit, there are disposed first electrically actuatable valves, which are closed in the de-energized normal state, and, between the compressor and the auxiliary circuit, there is disposed a second electrically actuatable valve, which is open in the de-energized normal state. The valves are actuated by an electronic control unit. The outlet ports of the first valves of the air-load circuits are in communication via check valves with the outlet port of the second valve, which is open in the de-energized normal state. If a compressed air demand exists in one of the load circuits, for example due to too-low reservoir pressure, the corresponding valve is activated by the control unit, whereby the air demand is covered by the compressor, while at the same time the second valve for the auxiliary circuit is closed. Failure of the compressor leads to a pressure drop, which is detected by the control unit, which closes the valves or keeps them closed, whereby the pressure in the circuits is maintained. A pressure-regulating valve determines the pressure level. In the event of failure of the pressure-regulating valve, overpressure is relieved via an overpressure valve. Pressure sensors monitor the circuits. The circuits are supplied with air via the second, normally open valve and via the check valves connected upstream from the circuits. If the electrical system fails, all valves go to normal state. Nevertheless, the compressor continues to run and supplies the circuits with air via the second, normally open valve of the auxiliary circuit, the system pressure being determined by a low-pressure relief valve of the auxiliary circuit. If one valve fails, the associated circuit can be supplied with air via the valve of the auxiliary circuit and the check valve. The known system is complex, since each load circuit is equipped with a compressed air reservoir.
[0003] DE 10004091 C2 describes a compressed air supply device for vehicle compressed air systems with a multi-circuit protective valve, a pressure regulator, a supply line for supplying the circuits of the multi-circuit protective valve with compressed air, and a compressor, which can be switched by means of a pneumatic switching device, a pilot valve for controlling the pressure regulator and the switching device being provided, and a throttle being interposed between the pilot valve and the switching device. Each circuit is provided with a compressed air reservoir. The pilot valve is controlled and/or regulated by an electronic control and/or regulation unit. Pressure sensors monitor the pressure in the circuits and in the supply line.
[0004] In vehicles with a compressed air brake system, it is known that the EU Brake Directive can be satisfied by providing separate compressed air reservoirs for the front-axle and rear-axle brake circuits. Additional compressed air reservoirs are used for other compressed air consumers, such as an air-suspension circuit, to ensure that the functionality of the brake system is not negatively influenced by the operation of such further compressed air consumers. Such known compressed air systems with separate compressed air reservoirs for a plurality of compressed air load circuits are quite costly.
SUMMARY OF THE INVENTION
[0005] Generally speaking, in accordance with the present invention an improved compressed air system is constructed and arranged in such a way that—with the exception of the brake circuits—the need for compressed air reservoirs for further compressed air load circuits, such as air-suspension circuits, can be very largely eliminated, without having to fear negative consequences for the brake circuits.
[0006] The present invention provides electrically actuatable valves, preferably solenoid valves, for the individual load circuits. By virtue of the inventively designed compressed air system there are achieved cost savings, because there is no need for compressed air reservoirs for further compressed air consumers, especially for the air-suspension circuit including the associated components. The reservoirs for the service-brake circuits are not dispensed with. By virtue of the inventive design, the costs for the overall system can be reduced. The installation complexity is less. In the case of pressure demand, the further compressed air consumers, especially the air-suspension circuit, can be filled primarily by the service-brake circuits as long as the brake pressures of the brake circuits are in conformity with applicable legal regulations, for which purpose it is merely necessary to open the normally closed solenoid valve of the air-suspension circuit, since the solenoid valves of the service-brake circuits are normally open, or in other words in de-energized normal state. In the compressed air suspension-circuit without compressed air reservoir, the switching frequency of the normally closed solenoid valve is reduced, since actuation takes place only in the case of a request for compressed air from the electronically controlled air-suspension system (ECAS). The system safety and system availability are improved. Because the solenoid valve is closed during normal operation, no reactions due to the air-suspension circuit are felt in the brake circuits.
[0007] Still other objects and advantages of the present invention will in part be obvious and will in part be apparent from the specification.
[0008] The present invention accordingly comprises the features of construction, combination of elements, and arrangements of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention will be described in more detail hereinafter on the basis of the accompanying drawing, in which:
[0010] FIG. 1 shows an air-processing system according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] Referring now to FIG. 1 , where compressed air lines are represented by solid lines and electrical lines by broken lines, there is shown a compressed air system 2 with a compressed air supply part 4 and a compressed air consumer part 6 . Compressed air supply part 4 comprises a compressor 7 , a compressor control device 8 and an air-dryer part 10 .
[0012] Compressed air consumer part 6 is provided with a compressed air distributor line 14 , a plurality of electrically actuatable solenoid valves 16 , 18 , 20 , 22 , 24 with restoring springs and a plurality of compressed air load circuits 26 , 28 , 30 , 32 , 34 , 36 , 38 supplied with compressed air via the solenoid valves.
[0013] From compressor 7 , a compressed air supply line 40 leads via a filter 42 , an air dryer 44 and a check valve 46 to distributor line 14 , from which there are branched off lines 48 , 50 , 52 , 54 , 56 leading to the solenoid valves. From the solenoid valves, compressed air lines 58 , 60 , 62 , 64 , 66 lead to the load circuits. Line 62 splits into lines 62 ′ and 62 ″ leading to circuits 30 and 32 , a check valve 68 also being disposed in line 62 ″. A pressure limiter 70 is disposed in supply line 52 . Line 54 , which leads to solenoid valve 22 , branches off downstream from pressure limiter 70 . Line 64 splits into lines 64 ′ and 64 ″ leading to circuits 34 and 36 .
[0014] Pressure sensors 72 , 74 , 76 , 78 , 80 , 82 monitor the pressure in the consumer loops and in distributor line 14 , and transmit the respective pressure as a pressure signal to electronic control unit 84 , which directly controls the solenoid valves.
[0015] Load circuits 26 , 28 can be, for example, service-brake circuits, and load circuit 30 can be a trailer-brake circuit, in which case normally two lines, a supply line and a brake line, lead to the trailer. Load circuit 32 can be a parking-brake circuit with spring accumulator, and load circuits 34 and 36 can be secondary load circuits, such as operator's cab suspension, door controller, etc., in other words, all components that have nothing to do with the brake circuits. Load circuit 38 is designed as a high-pressure circuit for an air-suspension system (represented as an air bellows). An air-suspension system normally requires high pressure, because the air-suspension bellows exhibit large volumes and relatively high pressures.
[0016] Service-brake circuits 26 , 28 are provided with compressed air reservoirs 90 , 92 in conformity with EU Directive 98/12.
[0017] The inventive compressed air system makes it possible to dispense with compressed air reservoirs in circuits 30 , 32 , 34 , 36 and particularly in air-suspension circuit 38 . As an example, it is permissible to supply other compressed air load circuits from the service-brake circuits (circuits 26 and 28 ), provided the braking function or braking action of service-brake circuits 26 and 28 is not impaired.
[0018] Via a line 40 ′, compressor 7 is mechanically (pneumatically) controlled by compressor controller 8 . Compressor controller 8 comprises a solenoid valve 94 of small nominal width that can be switched by electronic control unit 84 . In the de-energized normal state it is vented, as illustrated, whereby compressor 7 is turned on. If compressor 7 is to be turned off, for example because all load circuits are filled with compressed air, control unit 84 changes over solenoid valve 94 so that the pressure-actuatable compressor is turned off via line 40 ′. If solenoid valve 94 is switched to de-energized condition, for example because a load circuit needs compressed air, solenoid valve 94 is again switched to the normal state illustrated in the drawing, whereby line 40 ′ is vented and in this way compressor 7 is turned on.
[0019] Air-dryer part 10 comprises a solenoid valve 100 with small nominal width, whose inlet 102 is in communication with distributor line 14 and via whose outlet 104 there is pneumatically switched a shutoff valve 106 , which is in communication with supply line 40 of compressor 7 and serves for venting of the air dryer.
[0020] When solenoid valve 100 is switched to passing condition, compressor 7 no longer discharges into the load circuits but instead discharges via valve 106 to the atmosphere. At the same time, dry air flows from distributor line 14 (out of reservoirs 90 , 92 of the service-brake circuits) via solenoid valve 100 , throttle 108 and a check valve 110 through air dryer 44 for regeneration of its desiccant and further via filter 42 and valve 106 to the atmosphere.
[0021] Reference numeral 112 denotes an overpressure valve.
[0022] Solenoid valves 16 , 18 , 20 , 22 , 24 are controlled by control unit 84 , solenoid valves 16 to 22 of load circuits 26 to 34 being open in de-energized normal state, while solenoid valve 24 of air-suspension circuit 38 is closed in de-energized normal state. Pilot-controlled solenoid valves can also be used. The pressure in the circuits is directly monitored at the solenoid valves by pressure sensors 72 , 74 , 76 , 78 , 80 . Air-suspension circuit 38 is electronically controlled by a control device 120 (also known as ECAS), which is connected to electronic control unit 84 via a data line 122 .
[0023] If the pressure were to drop in a load circuit, for example in circuit 30 (trailer-brake circuit), the compressed air supply by the service-brake circuits also takes place via the open solenoid valves, the pressure in secondary load circuits 30 to 36 being adjusted by pressure limiter 70 to a lower level, such as 8.5 bar, than the pressure level of, for example, 10.5 bar in service-brake circuits 26 and 28 . Air-suspension circuit 38 is shut off by solenoid valve 24 and therefore is not in communication with the other circuits. It frequently has a higher pressure level, such as 12.5 bar.
[0024] If the reservoir in air-suspension circuit 38 is dispensed with, as described hereinabove, and as is made possible by the specially described arrangement and construction of the solenoid valves, only the reservoir volumes of the service-brake circuits and a small dead volume up to the load circuits exist. If a small leak occurs in an air-suspension system without compressed air reservoir, frequent regulation via solenoid valve 24 would normally be required. Because of the large nominal width of solenoid valve 24 , the corresponding regulation algorithm is extremely complicated, and so it would be desirable to open the solenoid valve only when the air-suspension circuit actually needs compressed air. In this way it is possible to dispense with the pressure regulation described hereinabove.
[0025] In the event of a compressed air demand, for example because of a level-regulation function, control device 120 , which is connected via data line 122 to electronic control unit 84 , sends a compressed air request signal via the data line to electronic control unit 84 . This checks whether the pressures (or flow rate, air mass or energy) in brake circuits 26 and 28 are in conformity with the specified index values. If this is the case, control unit 84 switches solenoid valve 24 from the closed normal position to the open position, whereby communication with reservoirs 90 , 92 of the service-brake circuits is established via normally open solenoid valves 16 , 18 . Air-suspension circuit 38 is then filled from compressed air reservoirs 90 , 92 of brake circuits 26 , 28 via open solenoid valves 16 , 18 thereof. If the pressure in the brake circuits, measured by pressure sensors 72 , 74 , drops below the specified value, this is detected by electronic control unit 84 , which thereupon closes solenoid valve 24 of air-suspension circuit 38 and turns on compressor 7 via compressor control device 8 by changing over solenoid valve 94 . The compressor discharges into the brake circuits. When the index pressure has been restored in the brake circuits, electronic control unit 84 switches solenoid valve 24 of air-suspension circuit to open position once again, so that the air-suspension circuit continues to be filled by the brake circuits or by compressed air reservoirs 90 , 92 thereof. This cyclic filling by the brake circuits is continued until the index pressure is reached in air-suspension circuit 38 . The pressure-request signal disappears, solenoid valve 24 is closed once again and the brake circuits are filled once again. Thereafter, solenoid valve 94 is switched to the vented normal state once again in order to turn off compressor 7 and to vent line 40 ′.
[0026] The compressor normally discharges only into brake circuits 26 , 28 . If necessary, it can also discharge into the air-suspension circuit, in which case, depending on the air pressure in the brake circuits, solenoid valves 16 , 18 of the brake circuits can be closed.
[0027] Solenoid valves 20 and 22 of the secondary load circuits remain open, since the pressure in associated load circuits 30 to 36 is limited by pressure limiter 70 .
[0028] As discussed above, air-suspension circuit 38 usually has a higher pressure level than the other circuits; nevertheless, it needs pressure relatively infrequently, and so, according to the present invention, it is closed in de-energized condition. In the event of a demand, it also does not need its compressed air within a very short time (msec or fractions of seconds), and so, a certain dead time can be tolerated for communication with electronic control unit 84 ; the air-suspension circuit is therefore normally closed. Circuits 30 to 36 are supplied from reservoirs 90 and 92 of service-brake circuits 26 and 28 , and so valves 16 , 18 , 20 and 22 thereof are open in de-energized condition during normal driving.
[0029] As an alternative to the pressure, it is also possible to monitor other variables of state, such as air flow rate, air mass and energy, in the load circuits and distributor line.
[0030] It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and since certain changes may be made in the above constructions without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.
[0031] It is also 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 of the scope of the invention which, as a matter of language, might be said to fall therebetween.
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An electronic compressed air system for vehicles includes a compressed air supply part having a compressor, a compressed air consumer part having load circuits forming an air-suspension circuit, and service-brake circuits having reservoirs. The load circuits are supplied with compressed air via solenoid valves. The pressure in the load circuits is monitored by pressure sensors whose signals are evaluated by an ECU that controls the solenoid valves. The solenoid valve of the air-suspension circuit does not include reservoirs and is closed in the de-energized normal state. The solenoid valves of other load circuits, especially of the service-brake circuits are open in the de-energized normal state. With a pressure demand of the air-suspension circuit, the associated solenoid valve is switched by the ECU to open position to establish communication with the compressed air supply part and/or with the service-brake circuits or with the reservoirs thereof, to refill the air-suspension circuit.
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FIELD OF THE INVENTION
The present invention relates generally to sensors for determining a level of current in a conductor, and particularly to a Hall effect current sensor system that is substantially immune to electrical noise.
BACKGROUND OF THE INVENTION
A variety of sensors are used to measure the amount of current flowing through a conductor. One such example is an open loop Hall effect current sensor. An open loop Hall sensor that measures current flowing through a conductor and provides an output signal proportional to the level of current. Such a Hall effect current sensor can include a gapped, ferrous-based core which surrounds the conductor and a Hall generator. The Hall generator is placed within the gap of the core.
Such an open loop configuration is typically susceptible to electrical noise on the conductor. Thus, the accuracy of the Hall generator potentially suffers due to electrical noise on the conductor being indirectly coupled through the core to the Hall generator.
The metallic core typically has a significant amount of surface area in parallel with the conductor, and a measurable amount of electrical noise can be capacitively coupled from the conductor to the floating core. Additionally, when a typical Hall generator is positioned in a core gap, the ends of the core have a significant amount of surface area in parallel with the generator. This allows noise on the core to be capacitively coupled to the generator. If the level of noise coupled indirectly from the conductor to the generator (via the core) is significant, the Hall effect current sensor provides an output signal that inaccurately represents the level of current in the conductor.
It would be advantageous to utilize an open-loop system in which the Hall generator is substantially immune from direct or indirect electrical noise.
SUMMARY OF THE INVENTION
The present invention features a system for measuring current flowing through a conductor. The system includes a core having a general ring-shape. The gap within the gapped core is defined by a pair of parallel faces. The core contains a central opening for receiving a conductor therethrough. The system further includes a Hall generator disposed in the gap and a ground. The core is electrically connected to the ground.
According to another aspect of the invention, a system is provided for detecting a current level in a conductor. The system includes a metallic core having an opening therethrough. The metallic core further includes a gap extending from the opening to an outer surface of the core. The system also includes at least one conductor extending through the opening, and a sensor disposed in the gap. The sensor cooperates with the core in detecting a current in at least one conductor and outputs a voltage proportional to the current. The system further includes a ground and an electrical connection between the core and the ground.
According to another aspect of the present invention, a method is provided for detecting a current level or change in current level in a conductor. The method includes locating a core about a conductor such that the core does not physically contact the conductor. The method further includes placing a gap in the core, and inserting a Hall generator in the gap. The Hall generator is arranged such that it cooperates with the core to output a signal proportional to the current in the conductor. The method further includes electrically grounding the core to provide immunity from electrical noise.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:
FIG. 1 is a side view of an exemplary Hall generator utilized in a preferred embodiment of the present invention;
FIG. 2 is a front view of a sensor system according to a preferred embodiment of the present invention;
FIG. 3 is a side view of the system illustrated in FIG. 2; and
FIG. 4 illustrates an alternate embodiment of the system illustrated in FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring generally to FIG. 1, an exemplary Hall generator 10 is illustrated. Hall generator 10 represents a typical embodiment of Hall generator for use in the present invention. Hall generator 10 includes a Hall plate 12 that cooperates with the a Hall substrate 14 . Additionally, Hall generator 10 includes leads 16 designed to carry an output signal in the form of an output voltage that is proportional to the magnetic flux acting on Hall generator 10 , which is proportional to the current passing through the conductor.
Hall generator 10 is utilized in a Hall effect current sensor system 18 , as illustrated in FIG. 2 . Sensor system 18 includes a core 20 that is typically formed from a ferrous-based material. Core 20 includes a central opening 22 through which a conductor 24 extends. Core 20 is generally ring-shaped and includes a pair of core faces 26 that are generally parallel to each other across a gap 28 . Ring-shaped includes a variety of shapes including rectangular, U-shaped, and circular. Gap 28 preferably is sized to receive Hall generator 10 , and most preferably is sized such that core faces 26 lie proximate to the Hall generator 10 without contacting Hall generator 10 . As current passes through conductor 24 , a magnetic flux proportional to the current is established in core 20 and sensed by Hall generator 10 .
In the illustrated embodiment, core 20 is formed as a ring that has a generally rectangular shape, e.g. square, having four sides 30 . In this embodiment, central opening 22 also is substantially rectangular, e.g. square, and conductor 24 is rectangular, as illustrated. Also, core 20 preferably is formed from a plurality of laminations 32 to form a lamination stack 34 , as illustrated in FIG. 3 .
The arrangement of components in the Hall effect current sensor system 18 is selected to minimize electrical noise that can effect the signal output by Hall generator 10 . For example, core 20 is electrically connected to-a ground 36 . Ground 36 can either be a circuit ground or a protective “earth” ground. This grounding of core 20 has no detrimental effects with respect to the magnetic properties or characteristics of the metallic core 20 . However, the grounding substantially reduces or eliminates the effects of electrical noise that can be capacitively coupled from conductor 24 to a floating core, such as core 20 . Absent the grounding to ground 36 , this electrical noise can be capacitively coupled to Hall generator 10 due to the significant amount of surface area that core ends 26 have in parallel with generator 10 . Additionally, Hall generator 10 is made relatively immune to direct electrical noise on conductor 24 by positioning Hall plate 12 and Hall substrate 14 in a generally perpendicular orientation with respect to the electrical fields radiated from conductor 24 . (See FIG. 2 ).
Thus, Hall generator 10 is substantially immune from both direct electrical noise on conductor 24 and electrical noise that otherwise would be capacitively coupled from conductor 24 to core 20 and from core 20 to Hall generator 10 . Electrically connected core 20 to ground 36 effectively shunts the electrical noise away from Hall generator 10 . Consequently, sensor system 18 may be designed as an open loop system, illustrated in FIG. 2, because the voltage signal output through leads 16 remains stable and representative of the current passing through conductor 24 . This voltage signal can be used directly by a recipient device 38 . An exemplary recipient device 38 is any device or application for which or in which there is a need to sense or measure current.
An exemplary utilization of Hall effect current sensor system 18 is illustrated in FIG. 4 . In this particular implementation, core 20 is mounted to a circuit board 40 by an appropriate mounting structure 42 . Mounting structure 42 preferably holds core 20 generally perpendicular to the circuit board 40 , such that conductor 24 is generally parallel with the circuit board as it extends through central opening 22 . Also, the Hall generator 10 preferably is generally perpendicular to circuit board 40 to help isolate it from electrical noise that results from other components or circuits on board 40 .
Circuit board 40 may be designed in a variety of configurations for mounting in numerous devices, such as relays, that require accurate sensing of current level through one or more conductors. In this embodiment, ground 36 typically comprises a circuit ground disposed in or on circuit board 40 . The embodiment illustrated in FIG. 4 shows one of many potential uses and implementations of the unique Hall effect current sensor system 18 .
It will be understood that the foregoing description is of a preferred exemplary embodiment of this invention and that the invention is not limited to the specific forms shown. For example, the core may have a variety of configurations and sizes; the Hall generator preferably is centered with respect to the core ends and oriented perpendicular to conductor 24 , but those parameters may be altered; the materials utilized in forming the conductor and core may be varied depending on the specific application; and there may be several different types of recipient devices. These and other modifications may be made in the design and arrangement of the elements described above without departing from the scope of the invention as expressed in the appended claims.
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A system and method for measuring current flow through a conductor. The system includes a core having a general ring shape and a central opening. The core terminates at two ends that form a gap for receiving a Hall generator. The core is electrically coupled to a ground to prevent electrical noise on the conductor from being coupled to the Hall generator, thus permitting the direct use of the voltage signal output by the Hall generator.
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This invention relates to laser control techniques as especially to control techniques for microlithography lasers.
BACKGROUND OF THE INVENTION
Lithography Lasers
Integrated circuits are typically printed on silicon wafers using microlithography machines. There are two types of these machines: stepper machines and scanner machines. The light source for most of these machines currently being sold are gas discharge lasers. Currently the most used gas discharge lasers are the krypton-fluorine (KrF) excimer lasers which are pulse lasers operable at repetition rates up to about 1000 Hz or up to about 2000 Hz. The typical pulse energy is in the range of about 5 mJ to about 12 mJ. Most of these lasers now operating are the 1000 Hz models although the 2000 Hz models have now been available for about 18 months. Many of the details of a 1000 Hz KrF laser are described in U.S. Pat. No. 5,991,324. A 2000 Hz F 2 laser is described in U.S. Pat. No. 6,018,537; and a 2000 Hz KrF laser is described in U.S. patent application Ser. No. 09/157,067. A technique for pulse energy control of these lasers is described in U.S. Pat. No. 6,005,879. These patents and this patent application are incorporated herein by reference. As more completely described in the above referenced documents, lasing occurs in a resonance cavity typically created between a line narrowing module and an output coupler which is typically a partially reflecting mirror. The line narrowing module typically comprises a prism beam expander and a grating for narrowing the bandwidth of the beam. In most lithography lasers, a tuning mirror is used to select the center wavelength retro reflected from the grating which is done by the angle at which the laser beam illuminates the grating. The gain medium is an electric discharge region between two elongated electrodes. Laser gas for the KrF laser is a mixture of about 0.1% fluorine, 1% krypton and the rest a buffer gas neon.
Control Mechanisms
The energy of each pulse is typically controlled in an automatic feedback arrangement by adjusting the charging voltage of a pulse power system which provides a pulse discharge approximately proportional to the charging voltage. Between each discharge, the laser gas in the discharge region must be replaced. This is accomplished with a tangential blower which at 3500 rpm creates a steady gas flow between the electrodes of about 20 to 30 meters per second for 2000 Hz operation. This means that the laser gas flows about 1.25 cm between discharge at a pulse repetition rate of 2000 Hz. Since the discharge region is only about 0.5 cm wide, the products of one discharge are sufficiently moved out of the region before the subsequent discharge.
Burst Mode Operation
The temperature of the laser gas is controlled by a water cooled, finned heat exchanger to temperatures in the range of about 30° C. to 60° C. At continuous operation, for example at 1000 Hz, the temperature can be controlled without much variation, with time, although there is a temperature drop across the heat exchanger of a few degrees centigrade and a corresponding average temperature increase across the electrodes. Each pulse heats the discharge region, and this hot spot spreads out as the gas circulates around the chamber. At a blower speed of 3500 rpm, it takes about 10 to 15 milliseconds for the heated gas from a given discharge to return to the discharge region. When the laser is operating in a continuous mode, equilibrium conditions are quickly developed in the flow region around the laser chamber; however, continuous mode operation is not normal for lithography lasers. Lithography lasers are normally operated in a so-called “burst” mode. A typical burst mode would be “on” for 0.15 seconds at a repetition rate of 2000 Hz (for 300 pulses), then “off” for 0.3 seconds while the lithography machine moves to a new die region of the wafer, then “on” for another 0.15 second, and “off” again for 0.3 seconds. This operation continues until all of the die regions of the wafer (for example 120) are treated. Then the wafer is replaced with another wafer which may take a few seconds such a six seconds. Thus, one wafer per minute would be treated at this rate. This burst mode operation results in significant temperature swings in the laser gas which can directly and indirectly affect the quality of the laser beam.
Beam quality is extremely important for the lithography machines which are currently printing circuits with line widths in the range 0.25 micron. (A human hair is about 50 microns thick.) Therefore, lithography lasers are typically equipped with metrology equipment which measures for each laser pulse:
centerline wavelength
bandwidth
pulse energy
The laser also uses these values to report quality variation. Typical beam quality parameters are:
(1) Energy sigma (σ E ) defined as: σ E = ∑ i = m m + k ( E i - E T ) 2 k / E T
where m is the first pulse of a k pulse rolling window (k being the number of pulses in the window) and E T is a target pulse energy such as 10 mJ.
(2) Energy Variation from Target (E V ) also called “energy stability” defined as: E V =maximum value of E i −E T in a k-pulse window.
(3) Dose Variation (D V ) (also called “dose stability”) defined as: D V = ( ∑ i = m m + k E i k - D T ) / D T
where D T is a target dose for a k size window.
(4) Wavelength Sigma (σ λ ) defined as: σ λ = ∑ i = m m + k ( λ i - λ T ) 2 k
(5) Wavelength Variation (λ V ) also called “wavelength stability” defined as: λ V = ∑ i = m m + k λ i - λ T k
(6) Bandwidth (Δλ) defined as pulse spectral width at one half maximum intensity (FWHM).
By tradition, the units of σ E and D V are expressed in percent. E V units are millijoules, mJ. The units of σ λ , Δ λ and λ V are picometers, pm.
These values are stored temporarily in a memory buffer of the laser controller and can be read out to an external information processor or storage device or can be read by the stepper/scanner as desired.
Typical specifications for a KrF excimer laser might be:
Wavelength stability (40 pulse window)
=
±0.07
pm
Wavelength sigma
=
±0.06
pm
Bandwidth
=
0.6
pm
Dose stability (40 pulse window)
=
0.4
percent
Energy Sigma (40 pulse window)
=
12
percent
Energy stability (40 pulse window)
=
7.5
percent
These specifications are examples of the type of quality standards which are applied to determine if a laser's performance passes an acceptance test prior to shipment from the laser fabrication plant. These values are sometimes reported as maximum values during a specified period of time. The sigma values are typically reported as “3 sigma” values.
SUMMARY OF THE INVENTION
The present invention provides a lithograph quality optimization process for controlling laser beam parameters when changing operating modes. The laser is programmed to automatically conduct an optimization procedure preferably in less than one minute to adjust laser operating parameters such as blower speed, total gas pressure and F 2 partial pressure in order to optimize beam quality parameters.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows features of a lithography laser and a lithography machine.
FIG. 2 shows wafer throughout with 1 and 2 KHz lasers.
FIG. 3 is a 3D graph showing variation of dose stability with energy and repetition rate.
FIG. 4 shows advantages of optimization.
FIG. 5 shows relationship of pulse energy voltage, F 2 partial pressure and total pressure.
FIG. 6 shows line width as a function of pulse energy.
FIG. 7 shows results of an optimization according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Control of Beam Parameters
FIG. 1 is a block diagram showing the principal equipment utilized to practice the present invention. Beam parameters (centerline wavelength, bandwidth and pulse energy) of the laser beam from laser chamber 6 are measured by wavemeter 10 . Laser controller 102 uses this information in feedback techniques to control pulse energy by regulating the charging voltage in high voltage pulse power system 8 and to control the wavelength by controlling through stepper motor 13 the pivot position of tuning mirror 14 which in turn controls the angle at which the beam expanded by a three-prism beam expander 12 illuminates grating 16 . The bandwidth in this system can be adjusted to some extent by bending of the grating with bending mechanism 18 . Laser controller 102 also does beam quality analysis and reports beam quality information 19 to stepper or scanner 20 which also gives direction to laser controller 102 .
Cause of Beam Quality Variations
As indicated in the Background section, continuous operation of the laser can result in very stable conditions and very stable beam quality parameters. Also stable operation permits adjustments of laser parameters such as fluorine concentration, charging voltage total gas pressure, blower speed, tuning mirror position and grating curvature to optimize beam quality parameters. Burst mode operation, even when the periodic bursts repeat continuously over long periods, cause substantial temperature fluctuations in the discharge region and other effects which tend to affect beam quality. Laser controller 102 is programmed with algorithm which automatically adjusts the charging voltage to control pulse energy and integrated dose to desired levels and to control the position of tuning mirror 14 to provide control of wavelength. Automatic adjustment of cooling water flow maintains average gas temperature within a desired range. In addition, for operation in a continuous burst mode, the fluorine concentration, the total pressure and the blower speed should be adjusted to provide optimized performance for that particular mode.
In accordance with the present invention, as the stepper or scanner illumination requirements change necessitating a change in the laser mode of operation, the laser is notified of the change and the laser is preprogrammed to automatically optimize itself for the new mode of operation with the objective of optimizing integrated circuit quality and minimizing total cost of operation for the lithography system.
Need to Optimize for Quality and Cost
State of the art lithography lasers currently being sold for use on stepper and scanner machines are designed for operation at about 2000 Hz with pulse energies in the range of about 10 mJ. Many resists used by the integrated circuit fabricators can fully utilize all of the light energy produced by these lasers so that throughput (in terms of wafers per hour) can be substantially increased with the 2000 Hz laser as compared with 1000 Hz lasers This means greater throughput. The general relationship between resist sensitivity and throughput for 1 KHz and 2 KHz lasers is shown in FIG. 2 . However, some resists have sensitivity values so low that integrated circuit quality would be compromised if laser energy were used at design values. In these situations, the laser can be operated at pulse energies below the design value; at repetition rate below design rate; the output beam could be attenuated or any combination of these techniques could be used.
Resists Variations
In many actual fabrication situations, due to use of different resists, needed beam energies can vary substantially over a production day. However, resists typically changes occur between wafer batches so that illumination requirements do not change more often than many minutes or several hours.
Laser Optmization
There are several ways to reduce illumination rates. For example, if because of a change in resist, illumination requirements are reduced by half, it would be a simple matter to reduce the pulse energy by one-half or the pulse rate by one-half or both could be reduced by one-fourth. In the past, the choices have been made without much thought given to the consequences. Applicants, however, have developed techniques to permit proper choices to be made to optimize integrated circuit quality and cost of operation.
Dose Stability Effects
An extremely important beam quality parameter is dose variation, also called dose stability. This parameter is defined above. It tells the operator how laser energy applied to the resist on a die area of a wafer differs from a target dose. As stated above, a typical specification would be 0.4 percent maximum variation over a test period. Applicants have performed experiments to determine the effect on dose variation of changing pulse energy and/or repetition rate of a laser optimized for operation at certain pulse energies and repetition rates. For example, FIG. 3 is a 3-D graph showing these effects for a laser optimized to operate at an average power of 1.1 Watt at 10mJ and 1.1 KHz. Dose stability at these operating conditions is about 0.3%. However, reducing the power to 0.8 watts by lowering the pulse rate to 1000 Hz and the pulse energy to 0.8J would increase the dose variation to more than 0.4% (an increase of more than 30%!).
Preferred Optimization Process
Applicants have determined that very substantial improvements in beam quality can be obtained by utilizing a relatively simple optimization process when changing beam illumination requirements. A preferred process is as follows:
(1) Prior to exposing a lot, scanner informs the laser about the laser's required repetition rate and energy (determined by the process engineer). Applicants refer to this as a “LOT CHANGE” signal.
(2) The laser controller is programmed with a control program which uses the lot change signal to optimize its conditions. In this preferred embodiment, the parameter used for laser's internal optimization are the following:
Total gas pressure
F 2 partial pressure
Speed of the laser's blower (lower repetition rate requires lower blower speed)
Adjustment of laser's energy control algorithm.
(3) The laser then checks itself for optimum parameters by initiating test pulses and for a few seconds then informs the scanner when it is ready for exposure.
Tests show that this process takes less than 1 minute, which is usually less than the time taken to change the lot.
The reader should note that variable repetition rate and variable energy operation are achieved without any change to laser modules. The optimization process described here is completely automated and does not require user intervention.
Total Gas Pressure and F 2 Pressure
For a given F 2 pressure, the laser's output energy depends on the total gas pressure. Thus, the laser's output energy may be changed by adjusting the total pressure of the laser. For a particular laser tested by Applicants, the relationship between total gas pressure, charging voltage and pulse energy is shown in FIG. 5 . The laser computer is programmed with this information and uses it to determine a total gas pressure to achieve a desired pulse energy. This takes less than 30 seconds. Also, the linewidth shows a slight dependence on energy, but this appears to be small.
The reader should note that the desired pulse energy could also be achieved by changing the charging voltage and leaving the total pressure and F 2 concentration unchanged. Alternatively, F 2 concentration could be changed while keeping charging voltage and total pressure unchanged. However, several laser parameters can be adversely affected by changes in F 2 concentration or the charging voltage. The presumption is prior to the called-for change, the laser was operating at optimum F 2 and charging voltage conditions. Changing the total gas pressure changes pulse energy substantially but has minimal effect on beam quality.
Total gas pressure is increased by injecting a mixture of 99 percent Ne and 1.0 percent Kr with no F 2 . Total gas pressure is decreased by releasing gas from the chamber. When this happens, some of the F 2 will be released which will cause the efficiency of the laser to decrease. The controller is programmed therefore to inject (coincident or approximately coincident with the release) an amount of fluorine equal to the amount lost. This whole process takes less than 30 seconds. The principal advantage of this technique is that the F 2 concentration is not changed; therefore, there is no adverse affect on beam quality due to non-optimum F 2 concentrations.
Blower Speed
As indicated in the Background section, the gas flow between the electrodes must be great enough to remove from the discharge region the products (including heat) of a discharge prior to the next discharge. This requires a gas velocity of about 1.25 cm/0.5 ms at a pulse repetition rate of 2000 pulses per second. Thus if each pulse deposits about 2T of heat energy in the gas in the 0.5 cm wide discharge region that amount of heat energy is carried away by a “slug” of gas 1.25 cm long. For example, a laser may be operating at a pulse rate of 2000 Hz with the blower rotating at 3500 rpm to produce the needed 1.25 cm/0.5 ms flow rate. To reduce the illumination rate by 50% the mode of operation could be changed so that the repetition rate is reduced to 1000 Hz with all other conditions remaining the same.
In this new mode the 2T of heat energy is deposited in a slug of gas about 2.5 cm long.
Applicants have discovered that substantial reductions in pulse reductions in pulse repetition rates will adversely affect beam quality unless the blower speed is also reduced. As a rule of thumb, the preferred reduction in blower speed is proportional to the reduction in repetition rate. This discovery was surprising, since the prior belief was that it did matter how fast or for the products of a discharge were removed, so long as they were removed from the discharge region prior to the next pulse. However, Applicants have discovered that very minor temperature gradients from one side of the discharge region to the other can affect the wavelength of the laser beams due to the change of the index of refraction of the laser gas with temperature. A constant small gradient is no problem since it can be easily and automatically cancelled out by a very small automatic change in the pivot position of tuning mirror 14 . However, if the gradient is changing and changing rapidly especially in an unknown or random fashion, the laser controls will be less effective and beam quality will suffer.
Energy Algorithm
In this preferred embodiment laser controller 102 is equipped with a control algorithm such as that described in U.S. Pat. No. 6,005,879. This algorithm learns from previous bursts, what charging voltages are needed to produce the target energy in future bursts. The algorithm also keeps track of total energy in a burst so that the total dose energy is controlled at or close to a target dose. That patent has been incorporated herein by reference. This algorithm operates by calculating (based on the earlier data) and storing correction parameters in “bins” of a computer memory bank for each of the first “W” pulses (such as 40) of a burst. The bins are continuously updated. Therefore, with a change in mode these bins will be automatically corrected to provide optimized pulse and dose energy correction.
Applicants' Optimization Experiments
FIG. 4 shows the result of an experiments performed by Applicants to prove the advantages of the present invention. A KrF, 2000 Hz lithography laser was optimized using techniques discussed above for best performance at 2000 Hz. Then the repetition rate was reduced in the increments indicated in the chart at 60 in FIG. 4 and dose stability values were plotted. As shown in the 60 chart, performance was very poor at repetition rates at 1000 Hz and lower. Then the same experiment was repeated by the laser was optimized at each increment by reducing the blower speed in proportion to the pulse repetition rate. The results are shown at 62 in FIG. 4 . The results are very impressive. Dose stability is almost constant. Line width was well within specifications without such variation and wavelength stability was also well within specification throughout the range. There is as indicated a slight general increase in line width with pulse energy as shown in FIG. 7 and as shown in FIG. 6 .
Chart 64 shows a plot of pulse energy plotted as a function of millions of pulses for a series of tests. Chart 66 shows repetition rates for the tests. Chart 69 shows the charging voltage for the tests. Chart 70 shows total chamber pressure and F 2 partial pressure during the tests. Chart 72 shows measured dose stability and chart 74 and 76 respectively show line width and wavelength stability.
While the invention has been described above with specificity in terms of preferred embodiments, the reader should understand and recognize that many changes and alterations could be made without deviating from the spirit of the invention. Therefore, the scope of the invention should be determined by the appended claims and their legal equivalents.
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A lithograph quality optimization process for controlling laser beam parameters when changing operating modes. The laser is programmed to automatically conduct an optimization procedure preferably in less than one minute to adjust laser operating parameters such as blower speed, total gas pressure and F 2 partial pressure in order to optimize beam quality parameters.
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CROSS REFERENCE TO RELATED APPLICATION
The present application is related to copending application Ser. No. 09/566,832 filed on even date herewith, entitled “Imidazodiazepine Derivative,” by inventors F. Emery, W. J. Hunkeler, F. Jenck, J. R. Martin and A. Sleight.
BACKGROUND
Conventional means for making intermediate products used in the maufacture of imidazo[1,5-a][1,4]diazepine derivatives have been chracterised by low yields resulting in higher production costs for the final products. The low yields of the conventional production methods have also lead to problems regarding the disposal of unwanted byproducts which are concomitantly produced with the production of the desired intermediates.
SUMMARY OF THE INVENTION
The present invention relates to a process for manufacturing diazepine derivatives of the general formula
wherein
R 1 is lower alkyl;
R 2 is hydrogen; or
R 1 and R 2 are together —(CH 2 ) n — and n is 2 or 3;
R 3 is halogen, lower alkyl, lower alkoxy and m is 0, 1 or 2; and
R 4 is hydrogen or lower alkyl.
The compounds of general formula I are valuable intermediate products for the manufacture of imidazo[1,5-a][1,4]diazepine derivatives, like for instance 7-chloro-3-(5-dimethylaminomethyl-[1,2,4]oxadiazol-3-yl)-5-methyl-4,5-dihydro-imidazo[1,5-a][1,4]benzodiazepin-6-one, which diazepine derivatives show excellent psychopharmacological properties as agonists of the central benzodiazepine receptors.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of general formula I are obtained by the known process consisting of reacting a compound of general formula
wherein
R 3 is halogen, lower alkyl, lower alkoxy and m is 0, 1 or 2; and
R 4 is hydrogen or lower alkyl.
,
with a compound of general formula
wherein R 1 is lower alkyl;
R 2 is hydrogen; or
R 1 and R 2 are together —(CH 2 ) n — and n is 2 or 3.
This reaction step takes place in a polar solvent such as for instance DMF, under atmospheric pressure and at a temperature between 110° C. and the boiling point of the reaction mixture.
The compounds of formula II can be obtained, on their turn, by reacting a compound of formula
wherein
R 3 is halogen, lower alkyl, lower alkoxy and m is 0, 1 or 2.
,
with:
a) phosgene and hydrochloric acid in THF; or
b) ethyl haloformiate, e.g. ethyl chloroformiate, in dioxane and subsequent treatment with acetylchloride.
Both steps take place in a batch system, under atmospheric pressure and at the boiling temperature of the reaction mixture (see e.g. G. M. Coppola, “The Chemistry of Isatoic Anhydride”, Synthesis , Georg Thieme Verlag, (1980), pp 505-535).
The last step of the mentioned production pathway is characterised by low yields. This is mainly due to a low conversion of the reactants and, in certain cases, also to a low selectivity towards the desired product because of the formation of a side product of general formula
These low yield and selectivity imply higher costs for the production of the compounds of formula I and lead to important disposal problems since the compounds of formula V cannot be used for other purposes and must be therefore destroyed or recycled.
The above elucidated problems are addressed by the present invention by providing a process for manufacturing the compounds of general formula I which can overcome the disadvantages mentioned above.
The problem is solved, according to the present invention, by a process for manufacturing diazepine derivatives of the general formula I, comprising the step of reacting a compound of general formula II with a compound of general formula III, characterised in that said compound of general formula II and said compound of general formula III undergo chemical reaction in the absence of a solvent or in the presence of an apolar solvent.
It has been surprisingly found that the conversion, and in certain cases also the selectivity, towards the compound of formula I strongly increases if the reaction components (i.e. compounds of formula II and III) are not solvated in the reaction mixture. This situation can take place only if no solvent at all is added to the reaction mixture or if the reactants and/or products are not soluble in a given solvent. Being the present compounds of polar nature, apolar solvents can be used in the process of the invention for achieving the wished results.
Particularly preferred solvents are substituted benzene rings, such as xylenes, mesitylene, ethylbenzene, isopropylbenzene, etc. Most preferably, p-xylene or a mixture of xylenes are used as solvent for carrying out the process according to the present invention.
The reaction temperature is preferably set from 0 to 30° C. under the boiling temperature of the reaction mixture.
The process of the present invention is particularly suitable for the manufacture of 6-Chloro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione.
By way of examples, preferred embodiments of the present invention will now be described. Comparative tests were made in which the compounds of formulae II and III underwent reaction in the conventional manner, i.e. using DMF as (polar) solvent.
The yields of compound I (Y(CI)) depicted in Table 1 were measured on the purified product. The ratios of compounds I and V depicted in Table 2 (R(CI) and R(CV)) were directly obtained from the HPLC measurements (HP1050, column CC70/4 nucleosil 100-5Cl8HD), and refer to the molar percentage of CI and CV in the crude product of the reaction.
Y(CI)=100[mol CI/mol CII]
CI, CII, CV=compound of general formula I, II, V
EXAMPLE 1
6-Chloro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione
25.0 g (126 mMol) 5-chloro-1H-benzo[d][1,3]xazin-2,4-dione and 12.4 g (139 mMol) sarcosine were suspended in 100 ml p-xylene and heated at reflux (oil bath temperature (T ext ) <150° C.) for 2 hours. After cooling to room temperature (r.t.), the suspension was stirred one more hour. The precipitate was filtered off, washed with 25 ml p-xylene twice and dried at 50° C. under vacuum. The solid obtained was digested in 75 ml water one hour at 0° C., filtered off, washed with 25 ml water and dried under vacuum for 18 hours at 80° C. to yield 25.2 g (88% mol) of 6-chloro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione of m.p.=230-232° C.
MS (EI): 224 (M .+ , 52); 153 (68); 44(100).
EXAMPLE 2
6-Methyl-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione
1.0 g (5.6 mMol) 5-methyl-1H-benzo[d][1,3]xazin-2,4-dione and 0.57 g (6.4 mMol) sarcosine were suspended in 4 ml p-xylene and heated at reflux (T ext <150° C.) for 5.5 hours. p-Xylene was removed under reduced pressure and the solid residue was digested in 5.0 ml water one hour at 0° C., filtered off, and dried under vacuum for 18 hours at 80° C. to yield 0.93 g (81% mol) of 6-methyl-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione of m.p.=203.5-205° C.
MS (EI): 204 (M .+ , 94); 175 (38); 133 (100); 44 (100).
EXAMPLE 3
7-Fluoro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione
1.0 g (5.5 mMol) 6-fluoro-1H-benzo[d][1,3]xazin-2,4-dione and 0.54 g (6.1 mMol) sarcosine were suspended in 4.0 ml p-xylene and heated to reflux for 4 hours. The suspension was cooled to r.t. and the precipitate filtered off. The solid obtained was digested 30 minutes at 0° C. in 5 ml deionised water, filtered off and dried for 16 hours at 60° C. under vacuum to yield 0.92 g (80% mol) of 7-fluoro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione of m.p.>250° C.
MS (EI): 208 (M .+ , 94); 179 (100); 137(92).
EXAMPLE 4
7-Chloro-6-fluoro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione
1.0 g (4.6 mMol) 5-chloro-6-fluoro-1H-benzo[d][1,3]xazin-2,4-dione and 0.45 g (5.0 sarcosine were suspended in 4.0 ml p-xylene and heated to reflux (T ext =145° C.) for 7 hours. Solvent was removed under reduced pressure and the residue was digested in 2.0 ml deionised water 1 hour at r.t. The precipitate was filtered off and crystallized from 10 ml methanol and 10 ml diethylether to give 0.63 g (56% mol) of 7-chloro-6-fluoro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione of m.p. >250° C.
Concentration of the mother liquors and crystallization from 3 ml methanol and 9 ml diethylether gave an additional 0.13 g (11%) of 7-chloro-6-fluoro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione of m.p. >250° C.
MS (EI): 242 (M .+ , 56); 213 (58); 171(76); 44 (100).
EXAMPLE 5
(S)-6-Chloro-1,2,3,11a-tetrahydro-5H-pyrrolo[2,1-c][1,4]-benzodiazepine-5,11(10H)-dione
0.50 g (2.5 mMol) 5-chloro-1H-benzo[d][1,3]xazin-2,4-dione and 0.32 g (2.8 mMol) L-proline were suspended in 4.0 ml p-xylene and heated at reflux (T ext <150° C.) for 2.5 hours (gives a yellow solution). Upon cooling to r.t., a precipitate formed which was filtered off and dried at 60° C. under vacuum. The solid obtained was digested in 1.5 ml water one hour at 0° C., filtered off, washed with 1.0 ml water and dried under vacuum for 16 hours at 60° C. to give 0.49 g (78% mol) of (S)-6-chloro-1,2,3,11a-tetrahydro-5H-pyrrolo[2,1-c][1,4]-benzodiazepine-5,11(10H)-dione of m.p. >250° C.
MS (EI): 250 (M .+ , 40); 221 (30); 70(100).
EXAMPLE 6
(S)-1,10a-5-Chloro-2H-azeto[2,1-c][1,4]benzodiazepine-4,10(9H)-dione
1.0 g (5.1 mMol) 5-chloro-1H-benzo[d][1,3]xazin-2,4-dione and 0.56 g (5.6 mMol) (S)-azetidine-2-carboxylic acid were suspended in 6.0 ml p-xylene and heated to reflux for 24 hours. p-Xylene was removed under reduced pressure and the residue was partitioned between dichloromethane and water and the aqueous phase extracted with dichloromethane. The combined organic extracts were dried (Na 2 SO 4 ) and the solvent removed under reduced pressure. The brown solid obtained was digested in 5 ml tert-butyl-methylether for 16 hours at r.t., filtered and dried under reduced pressure to give 0.99 g (82% mol) of (S)-1,10a-5-chloro-2H-azeto[2,1-c][1,4]benzodiazepine-4,10(9H)-dione as a beige powder of m.p.=180-198° C.
MS (EI): 236 (M .+ , 44); 180 (24); 153(62), 56 (100).
EXAMPLE 7
(S)-1-Methyl-1,2,3,11a-tetrahydro-5H-pyrrolo[2,1-c][1,4]-benzodiazepine-5,11(10H)-dione
0.5 g (2.82 mMol) N-metyl-1H-benzo[d][1,3]xazin-2,4-dione and 0.36 g (3.1 mMol) L-proline were suspended in 1.0 ml p-xylene and heated to reflux for 1 hour (goes into solution upon heating). After cooling to r.t., the reaction mixture was diluted with 10 ml dichloromethane and 5 ml deionised water and the phases separated. The aqueous phase was extracted with 8 ml dichloromethane twice. The combined organic extracts were dried (Na 2 SO 4 ) and evaporated. The residue was digested in 2 ml tert-butyl-methylether for 2 hours at r.t. to give 0.53 g (81.5% mol) of (S)-1-methyl-1,2,3,11a-tetrahydro-5H-pyrrolo[2,1-c][1,4]-benzodiazepine-5,11(10H)-dione as beige crystals of m.p.=117-118.5° C.
MS (EI): 230 (M .+ , 56); 161 (99); 133 (90); 105 (88); 70(100).
EXAMPLE 8
6-Chloro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione
1.0 g (5.0 mMol) 5-chloro-1H-benzo[d][1,3]xazin-2,4-dione and 0.50 g (5.56 mMol) sarcosine were suspended in 4.0 ml of a mixture of xylenes and heated at reflux (T ext <150° C.) for 4 hours. After cooling to room temperature, the suspension was stirred one more hour. The precipitate was filtered off, washed with 1.5 ml hexane twice and dried at 60° C. under vacuum. The solid obtained was digested in 3.0 ml water one hour at 0° C., filtered off, washed with 2.0 ml water and dried under vacuum for 4 hours at 60° C. to yield 0.86 g (74% mol) of 6-chloro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione of m.p.=235-237° C.
MS (EI): 224 (M .+ , 48); 195(34); 153(60) 126(36), 44(100).
EXAMPLE 9
7-Chloro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione
1.0 g (5.06 mMol) 6-chloro-1H-benzo[d][1,3]xazin-2,4-dione and 0.67 g (7.59 mMol) sarcosine were thoroughly mixed and heated to 140° C. for 2 hours then 150° C. for 20 hours. The brown powder obtained was cooled to r.t. and digested in 4.0 ml water at 0° C. for 1 hour, filtered and washed with 1.0 ml water. After drying under vacuum, 1.0 g (88% mol) 7-chloro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H) -dione was obtained as a beige powder of m.p. >250° C.
MS (EI): 224 (M .+ , 78); 195(86); 153(80), 44(100).
EXAMPLE 10
(S)-6-Chloro-1,2,3,11a-tetrahydro-5H-pyrrolo[2,1-c][1,4]-benzodiazepine-5,11(10H)-dione
0.50 g (2.5 mMol) 5-chloro-1H-benzo[d][1,3]xazin-2,4-dione and 0.43 g (3.75 mMol) L-proline were finely ground together and heated to 150° C. for 18 hours. The brown powder obtained was digested in 2.0 ml water at 0° C. for 1 hour, filtered off and washed with 2.0 ml cold water to yield, after drying under vacuum, 0.57 g (91% mol) (S)-6-chloro-1,2,3,11a-tetrahydro-5H-pyrrolo[2,1-c][1,4]-benzodiazepine-5,11(10H)-dione as a beige powder of m.p. >250° C.
MS (EI): 250 (M .+ , 36); 221 (28); 194(28); 153(32); 126(30); 70(100).
TABLE 1
Reaction yields after purification.
Process of the invention
Comparative examples
Ex. No
Y(CI)
Y(CI)
1
88.0
65.0
2
81.0
58.0
3
80.0
74.5
4
67.0
40.0
5
78.0
71.0
6
82.0
10.0
7
81.5
not measured
8
74.0
65.0
9
88.0
69.0
10
91.0
71.0
TABLE 1
Reaction yields after purification.
Process of the invention
Comparative examples
Ex. No
Y(CI)
Y(CI)
1
88.0
65.0
2
81.0
58.0
3
80.0
74.5
4
67.0
40.0
5
78.0
71.0
6
82.0
10.0
7
81.5
not measured
8
74.0
65.0
9
88.0
69.0
10
91.0
71.0
As showed in the above tables, the process according to the present invention leads to yields in the desired product which are much higher than those obtainable with conventional processes. Therefore, the process according to the present invention enables a surprising increase of the productivity, thereby decreasing costs and disposal problems.
As stated above, the products obtained with the process according to the invention can be used for manufacturing imidazo [1,5-a][1,4]diazepine derivatives with excellent psychoarmacological properties. Example 11 illustrates a possible method for producing one of such diazepine derivatives.
EXAMPLE 11
7-Chloro-3-(5-dimethylaminomethyl-[1,2,4]oxadiazol-3-yl)-5-methyl-4,5-dihydroimidazo[1,5-a][1,4]benzodiazepin-6-one
Ethyl 7-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate
25.0 g 6-Chloro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione were suspended under stirring and argon atmosphere in 200 ml toluene and 32.1 ml N,N-dimethyl-p-toluidine. The suspension was heated to 100° C. and 11.2 ml phosphorus oxychloride were added over 30 minutes and stirring was pursued two and an half hours at 100° C. The dark-orange solution was cooled to 40° C. and toluene was removed under reduced pressure to give 82 g of a dark-orange oil.
Meanwhile, 81.2 ml hexamethyldisilazane and 265 ml tetrahydrofuran were mixed and cooled to −35° C. 229.5 ml Butyllithium were added over 45 minutes and, after stirring 30 minutes at −35° C., a solution of 35.2 g ethyl(dimethylamino-methylenamino)acetate in 70.4 ml tetrahydrofuran was added over 30 minutes. The orange solution obtained was stirred one more hour at −35° C. and a solution of the crude iminochloride in 100 ml tetrahydrofuran was added over 1 hour at −15° C. The dark red solution was stirred one hour at −15° C., then 18 hours at room temperature (r.t.). 75 ml Acetic acid were added in 10 minutes, then 75 ml deionized water were added in one portion and the orange suspension was heated at reflux for two hours. Tetrahydrofuran was removed under reduced pressure and the residue was partitioned between 200 ml dichloromethane and 100 ml deionized water. The phases were separated and the organic phase was washed with 100 ml aqueous HCl 1N twice and with 100 ml deionized water. The aqueous phases were extracted twice with 100 ml dichloromethane. The combined organic extracts were dried (Na 2 SO 4 ) and evaporated. The residue was digested in 200 ml n-heptane 30 minutes at r.t. and filtered off. The sticky crystals obtained were digested at reflux for 30 minutes in 213.5 ml ethanol, then stirred 3 hours to r.t. and 2 hours at −20° C. The precipitate (ethyl 7-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate) was filtered off, washed three times with 20 ml ethanol and dried under reduced pressure 16 hours at 60° C. Crude product: 23.4 g as a beige powder. m.p. 225.5-226.5° C.
7-Chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxamide.
22.8 g Ethyl 7-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]-benzodiazepine-3-carboxylate were suspended under stirring and argon atmosphere in 91.2 ml 1,4-dioxane. 14.1 ml Formamide and 13.9 ml sodium methanolate were successively added to yield a clear light-orange solution, which turned to a white suspension after 10 minutes. This suspension was stirred two hours at 30° C. 200 ml Deionized water were added in one portion and 1,4-dioxane was distilled off at 40° C. under reduced pressure. The remaining white suspension was stirred two hours at 0° C. and filtered. The precipitate (7-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxamide) was washed with 50 ml deionized water three times and dried under reduced pressure for 18 hours at 80° C. Crude product:19.43 g as a white powder. m.p. >250° C.
7-Chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carbonitrile.
19.0 g 7-Chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxamide were suspended under stirring and argon atmosphere in 95 ml 1,4-dioxane and 6.58 ml phosphorous oxychloride were added in one portion. The reaction mixture was heated to reflux for one hour giving a yellow solution, which was concentrated at 50° C. under reduced pressure. The residue was digested in 100 ml deionized water for two hours at r.t. The precipitate (7-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carbonitrile) was filtered off, washed three times with 30 ml deionized water and dried under vacuum at 80° C. for 18 hours. Crude product: 17.3 g as a light yellow powder. m.p. 238.5-239.5° C.
7-Chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxamidoxime.
16.8 g 7-Chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carbonitrile were suspended under stirring and argon atmosphere in 101 ml N,N-dimethylformamide and 13.48 g hydroxylamine hydrochloride were added in one portion. 34.2 ml Sodium methanolate were then added over 60 minutes to the yellow suspension, which turned to a colorless suspension. It was stirred one more hour at r.t., then cooled to 0-2° C. and 202 ml deionized water were added over 30 minutes. After stirring one more hour at 0° C., the precipitate (7-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxamidoxime (VIII)) was filtered off, washed twice with 40 ml deionized water and dried under vacuum at 70° C. for 18 hours. Crude product: 17.84 g as a white powder. m.p. >250° C.
7-Chloro-3-(5-chloromethyl-[1,2,4]oxadiazol-3-yl)-5-methyl-4,5-dihydro-imidazo[1,5-a][1,4]benzodiazepin-6-one.
8.0 g 7-Chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxamidoxime and 1.0 g magnesium oxide were suspended under stirring and argon atmosphere in 160 ml 1,4-dioxane. 2.7 ml Chloracetyl chloride were added in one portion and the white thick gel obtained was stirred 4 hours at r.t. and then 17 hours at reflux to give a lightly orange fluid suspension. 100 ml Dioxane were distilled off and the reaction mixture was cooled to room temperature. 180 ml Deionized water were added within 15 minutes and the suspension was stirred 1 hour at r.t. The precipitate was filtered off, washed with 50 ml deionized water twice and dried under vacuum at 80° C. for 18 hours. Crude product: 8.3 g as a light pink powder. This crude product was dissolved in 120 ml tetrahydrofuran at reflux and 0.83 g active charcoal Darco G 60 were added. The system was refluxed 1 hour, then filtered on 25 g Dicalit-Speedex and the filter cake was washed with three portions of 50 ml warm tetrahydrofuran. The filtrate was concentrated at 40° C. under reduced pressure. The residue was digested in 80 ml ethanol 1 hour at reflux, then stirred 16 hours at r.t. and finally 2 hours at 2° C. The precipitate (7-chloro-3-(5-chloromethyl-[1,2,4]oxadiazol-3-yl)-5-methyl-4,5-dihydro-imidazo [1,5-a][1,4]benzo-diazepin-6-one (IX)) was filtered off, washed with 2 portions of 25 ml cold tert-butyl methyl-ether and dried under vacuum 5 hours at 80° C. Crude product: 7.6 g as a light beige powder. m.p. 234-238° C.
7-Chloro-3-(5-dimethylaminomethyl-[1,2,4]oxadiazol-3-yl)-5-methyl-4,5-dihydro-imidazo[1,5-a][1,4]benzodiazepin-6-one. 7.0 g 7-Chloro-3-(5-chloromethyl-[1,2,4]oxadiazol-3-yl)-5-methyl-4,5-dihydro-imidazo-[1,5-a][1,4]benzodiazepin-6-one were suspended under stirring and argon atmosphere in 70 ml 1,4-dioxane and 25.7 ml dimethylamine (33% in ethanol) were added over 60 minutes. The reaction mixture was stirred one more hour at r.t. and then the solvents were removed under reduced pressure at 35° C. The residue was partitioned between 50 ml dichloromethane and 20 ml deionized water. The phases were separated and the organic phase was washed twice with 20 ml deionized water. The aqueous phases were extracted separately with the same portion of 25 ml dichloromethane, twice. The combined organic extracts were dried (Na 2 SO 4 ) and the solvent was removed under reduced pressure. Crude product: 8.0 g as a light yellow foam.
Purification
The crude product was dissolved in 40 ml ethanol at reflux and 400 mg active charcoal Darco G 60 were added. The system was stirred 1 hour at reflux, then filtered on a hot pad of Dicalit Speedex, which was washed with two portions of 40 ml hot ethanol. The filtrate was concentrated to 14 g under reduced pressure, heated to reflux and at this temperature and 40 ml tert-butyl-methylether were added over 5 minutes. The suspension was cooled slowly to r.t., stirred 16 hours, further cooled to 2° C. After stirring 1 hour at 2° C., the precipitate was filtered off, washed with 20 ml tert-butyl-methylether and dried 1 hour at 60° C. under vacuum. The so obtained powder was dissolved at reflux in 26 ml ethyl acetate. 6.5 ml Ethyl acetate were then distilled off and the turbid solution obtained was slowly cooled to r.t., then to 0° C. After 1 hour stirring at 0° C., the precipitate was filtered off, washed with 10 ml cold tert-butyl-methylether and dried under vacuum at 60° C. for 16 hours. The so obtained powder (7-chloro-3-(5-dimethylaminomethyl-[1,2,4]oxadiazol-3-yl)-5-methyl-4,5-dihydro-imidazo[1,5-a][1,4]benzodiazepin-6-one (I)) was crystallized a second time in 24.3 ml ethyl acetate according to the procedure described above. Product: 5.5 g as a white powder. m.p. 151.5-153° C.
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The present invention relates to a process for manufacturing diazepine derivatives of the general formula I
wherein R 1 is lower alkyl and R 2 is hydrogen, or R 1 and R 2 are together —(CH 2 ) n — and n is 2 or 3; R 3 is halogen, lower alkyl, lower alkoxy and m is 0, 1 or 2; R 4 is hydrogen or lower alkyl.
The compounds of general formula I are valuable intermediate products for the manufacture of imidazo [1,5-a][1,4]diazepine derivatives, like for instance 7-chloro-3-(5-dimethylaminomethyl-[1,2,4]oxadiazol-3-yl)-5-methyl-4,5-dihydro-imidazo[1,5-a][1,4]benzodiazepin-6-one, which diazepine derivatives show excellent psychopharmacological properties as agonists of the central benzodiazepine receptors.
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RELATED APPLICATION
The present application is related to a U.S. patent application Ser. No. 09/540,583 filed Mar. 31, 2000 and entitled “Magnetorheological Fluid Pumping System, the disclosure of which is incorporated by reference.
TECHNICAL FIELD
The present invention relates to a system for charging magnetorheological (MR) dampers with magnetorheological fluid and other damper components and, more particularly, to a system for effectively loading damper components into a damper cylinder during assembly while minimizing MR fluid leakage.
BACKGROUND OF THE INVENTION
Magnetorheological fluids that comprise suspensions of magnetic particles such as iron or iron alloys in a fluid medium have flow characteristics that can change by several orders of magnitude within milliseconds when subjected to a suitable magnetic field due to suspension of the particles. The ferromagnetic particles remain suspended under the influence of magnetic fields and applied forces. Such magnetorheological fluids have been found to have desirable electro-magnetomechanical interactive properties for advantageous use in a variety of magnetorheological (MR) devices, such as brakes, clutches, mounts and dampers.
In particular, linear acting MR dampers are commonly used in suspension systems, such as a vehicle suspension system and vehicle engine mounts. PCT patent application 10840, published Jan. 8, 1998 (the '840 application), discloses a proposed linear acting controllable vibration damper apparatus which includes a piston positioned in a magnetorheological fluid-filled chamber to form upper and lower chambers. The piston includes a coil assembly, a core, i.e. pole pieces, and an annular ring element positioned around the pole pieces to form an annular flow passage for permitting flow of the magnetorheological fluid between the chambers. A gas cup or diaphragm is positioned at one end of the cylinder to form a pressurized accumulator to accommodate fluid displaced by the piston rod as well as to allow for thermal expansion of the fluid. When the piston is displaced, magnetorheological fluid is forced through the annular flow passage. When the coil is energized, a magnetic field permeates the annular flow passage and excites a transformation of the magnetorheological fluid to a state that exhibits damping forces.
During assembly of a MR damper, magnetorheological fluid is typically injected into a charging assembly and loaded, along with the piston assembly, into the cylinder forming the damper chambers. If included, accumulator gas and a gas cup or diaphragm must also be injected and loaded into the cylinder. A conventional charging assembly includes a charging tube, a set of fill holes and valves for controlling MR fluid and gas flow through the holes. It has been found that MR fluid leakage can occur in the gap around the valve and corresponding hole during movement of the components from the charging assembly into the damper cylinder. This undesirable leakage can accumulate to significant amounts disadvantageously resulting in unacceptable, expensive MR fluid usage and increased clean-up costs.
Therefore, there is a need for a simple, effective and low cost charging system for charging a MR damper with MR fluid without undesirable leakage.
SUMMARY OF THE INVENTION
It is an object of the present invention, therefore, to provide a magnetorheological (MR) fluid damper charging system which effectively charges a MR damper with MR fluid and damper components while minimizing undesirable MR fluid leakage.
This and other objects of the present invention are achieved by providing a magnetorheological damper charging system comprising a charging body including a bore for receiving a damper piston and at least one inlet formed in the charging body for delivering magnetorheological fluid to the bore. The damper charging system also includes a magnetic field generating assembly mounted at the inlet and operable in an energized state to generate a magnetic field across at least a portion of the inlet to cause magnetorheological fluid in the portion of the inlet to experience a magnetorheological effect sufficient to prevent leakage flow through and from the inlet and in a de-energized state to permit fluid flow through the inlet. The charging system may also include a magnetorheological fluid supply and an inlet valve mounted at the inlet for controlling fluid flow from the fluid supply through the inlet into the bore. The inlet valve may be mounted for reciprocal movement between a closed position substantially blocking flow through the inlet and an open position retracted from the inlet. A clearance gap is positioned between the inlet valve and the charging body when the inlet valve is in the closed position so that the magnetorheological effect is experienced in the clearance gap.
The magnetic field generating assembly may include a coil mounted on the inlet valve, and the inlet valve may include a pin element extending through the coil and formed of a magnetic material. The pin element may include a tip portion positionable in the inlet when the valve is in the closed position. The magnetic field generating assembly may further include a nonmagnetic sleeve mounted on the inlet valve axially between the coil and the tip potion.
The system may include a first inlet for delivering magnetorheological fluid to the bore and a second inlet for delivering an accumulator fluid. A first inlet valve may be mounted on the charging body adjacent the first inlet while a second valve is mounted adjacent the second inlet. Each of the first and second inlets includes a clearance gap in which the magnetorheological effect is generated to prevent magnetorheological fluid from leaking from the respective clearance gap.
The present invention is also directed to a method of charging a magnetorheological damper with magnetorheological fluid, comprising the steps of providing a charging body including a bore for receiving a damper piston and at least one inlet formed in the charging body for delivering magnetorheological fluid to the bore. The method further includes the steps of providing a valve at the inlet for controlling flow through the inlet and opening the valve to permit magnetorheological fluid flow through the inlet into the bore. The method also includes the steps of closing the valve to block magnetorheological fluid flow through the inlet and generating a magnetic field across at least a portion of the inlet to cause magnetorheological fluid in at least a portion of the inlet to experience a magnetorheological effect sufficient to prevent leakage from the inlet. The method may further include the steps of inserting a damper piston into the charging body, displacing the damper piston and the magnetorheological fluid from the bore and eliminating the magnetic field from the inlet.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a is an end view of the MR damper charging system of the present invention;
FIG. 1 b is a cross-sectional view of the MR damper charging system of the present invention taken along plane 1 b — 1 b in FIG. 1 a ;
FIG. 1 c is an expanded view of the area A of FIG. 1 b ;
FIG. 2 is a cross-sectional view of the MR damper charging system of the present invention with the inlet valves in the open position;
FIG. 3 is a cross-sectional view of the MR damper charging system of the present invention with the inlet valves in the closed position;
FIG. 4 a is an expanded cross-sectional view of the tip portion of the inlet valve of FIG. 3 in the closed position; and
FIG. 4 b is a cross-sectional view of the tip portion of the valve taken along plane 4 b — 4 b in FIG. 4 a.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 a - 1 c, there is shown the magnetorheological fluid damper charging system of the present invention, indicated generally at 10 , designed to effectively minimize leakage of magnetorheological (MR) fluid from the system during filling of the system with magnetorheological fluid and charging an MR damper with magnetorheological fluid and damper components by displacing the fluid and components from the charging system into an MR damper cylinder 12 . MR damper charging system 10 generally includes a charging body 14 for engaging damper cylinder 12 , a first inlet valve 16 for controlling MR fluid flow into charging body 14 and a first magnetic field generating assembly 18 for reducing MR fluid leakage as discussed more fully hereinbelow.
Specifically, referring to FIG. 1 b, charging body 14 includes a longitudinal bore 20 extending therethrough for receiving a damper piston 22 for subsequent displacement out of charging body 14 into damper cylinder 12 . During assembly, bore 20 may also receive other damper components, such as a gas cup 24 and a seal cover assembly 26 , depending on the type of damper to be assembled. Gas cup 24 will function in the assembled damper as a floating piston separating a MR fluid chamber from a pressurized accumulator volume. The floating piston and accumulator volume of, for example, gas, is necessary to accommodate fluid displaced by piston rod 23 as well as to allow for thermal expansion of the MR fluid thereby permitting effective operation of the assembled MR damper. Of course, damper piston 22 may be any conventional damper used in magnetorheological damping devices while gas cap 24 may be any barrier conventionally used to separate the accumulator chamber from the MR fluid chamber, such as a flexible rolling diaphragm.
MR damper charging system 10 also includes a first inlet 28 in the form of a passage communicating at one end with bore 20 and at an opposite end with a MR fluid supply circuit 30 as best shown in FIGS. 1 b and 2 . A second inlet 32 is positioned a spaced axial distance along bore 20 from first inlet 28 and likewise communicates with bore 20 at one end while communicating with an accumulator gas supply circuit 34 at an opposite end. First inlet valve 16 is mounted for reciprocal movement in a valve block 36 mounted on charging body 14 . Charging system 10 also includes a second inlet valve 38 mounted for reciprocal movement in a second valve block 40 secured to charging body 14 adjacent second inlet 32 . First and second inlet valves 16 , 38 operate in substantially the same manner to control MR fluid and gas flow, respectively, through first and second inlets 28 , 32 . Specifically, as discussed more fully hereinbelow, first and second inlet valves 16 , 38 are moved between a closed position (FIG. 1 b ) blocking fluid and gas flow through the respective first and second inlets 28 , 32 and an open position (FIG. 2) permitting fluid and gas flow through the inlets. First and second inlet valves 16 , 38 may be operated by any conventional actuating device capable of selectively and effectively moving the valves between the open and closed positions.
Importantly, MR damper charging system 10 of the present invention also includes magnetic field generating assembly 18 associated with first inlet valve 16 and a magnetic field generating assembly 42 associated with second inlet valve 38 . The specific structure of first inlet valve 16 and magnetic field generating assembly 18 will now be discussed in detail. A construction of second inlet valve 38 and magnetic field generating assembly 42 is identical to first inlet valve 16 and magnetic field generating assembly 18 and, therefore, although the valve structure is most clearly shown in FIG. 1 c with respect to second inlet valve 38 , the following description will cover both valves and magnetic field generating assemblies. First and second inlet valves 16 , 38 each 20 includes a valve body 44 including integral pin element 46 extending from valve body 44 . Pin element 46 includes a tip portion 48 positioned at an outer distal end for positioning within the respective inlet 28 , 32 when the respective valve is in a closed position. Magnetic field generating assemblies 18 and 42 each include a coil 50 mounted on the valve body 44 and positioned around pin element 46 . Coil 50 is connected to an electrical source (not shown) via electrical leads 52 . Magnetic field generating assemblies 18 and 42 also include a non-magnetic sleeve 54 securely mounted on pin element 46 adjacent tip portion 48 for engaging a corresponding valve recess 56 formed in charging body 14 . Nonmagnetic sleeve 54 is formed of a nonmagnetic material, such as stainless steel. As best shown in FIG. 1 c, various O-ring grooves and complementary O-rings 58 may be formed in and positioned on the outer surface of nonmagnetic sleeve 54 to form an effective seal against the inner wall of valve recess 56 when first and second inlet valves 16 and 38 are in the closed position.
Magnetic field generating assemblies 18 and 42 effectively generate a magnetic field or flux which minimizes unwanted leakage during operation in the following manner. First, it should be noted that pin element 46 , charging body 14 and valve blocks 36 , 40 are all formed of magnetic material. When first and second inlet valves 16 , 38 are in the closed position as shown in FIG. 1 b, electrical current may be supplied to coil 50 via leads 52 . Upon energization of coil 50 , a magnetic field is generated in a pattern as shown in FIG. 1 c as magnetic flux is channeled by nonmagnetic sleeve 54 through pin element 46 . With specific reference to FIG. 4 a, the magnetic lines of flux specifically extend from tip portion 48 of pin clement 46 across an inherent annular clearance gap 60 (FIG. 4 b ) formed between tip portion 48 and the surrounding wall forming first and second inlets 28 , 32 into charging body 14 . As a result, magnetorheological fluid present in clearance gap 60 experiences a magnetorheological effect sufficient to prevent leakage flow through, and MR fluid flow from, clearance gap 60 . This stabilization of MR fluid in clearance gap 60 thereby prevents the MR fluid in clearance gap 60 from flowing into bore 20 . The MR effect experienced by the MR fluid in clearance gap 60 prevents clearance gap 60 from functioning as a drain passage permitting flow around an outer seal 62 , i.e. O-ring, positioned on the outer surface of seal cover assembly 26 .
A better understanding of the advantage of the present charging system in minimizing undesirable leakage will best be understood in conjunction with a description of the operation of charging system 10 . As shown in FIG. 1 b, first and second inlet valves 16 and 38 are initially in a closed position blocking fluid flow through the respective inlets. Damper cylinder 12 is connected to one end of charging body 14 while gas cup 24 , damper piston 22 and seal cover assembly 26 are moved into position within bore 20 . Gas cup 24 is positioned in bore 20 between first inlet 28 and second inlet 32 while damper piston 22 is also positioned between first and second inlets 28 , 32 to the right of gas cup 24 as shown in FIG. 1 b . Referring to FIG. 2, at a preselected moment, first and second inlet valves 16 , 38 are moved into an open position to permit MR fluid flow from fluid supply circuit 30 through first inlet 28 into chamber 66 and gas from gas supply circuit 34 to flow through second inlet 32 into a gas chamber 68 to the left of gas cup 24 . During this filling operation, MR fluid flows from chamber 66 through conventional passages 70 formed in damper piston 22 into chamber 64 thereby filling both chambers 66 and 64 . Once the chambers are full, first and second inlet valves 16 , 38 are moved back into the closed position as shown in FIG. 1 b blocking MR fluid and gas flow into the respective chambers. A press member 72 , which may have been previously used to insert each damper component into bore 20 , is then moved to the left in bore 20 as shown in FIG. 3 so as to displace seal cover assembly 26 , damper piston 22 and gas cup 24 toward damper cylinder 12 . During this pressing operation, seal cover assembly 26 necessarily moves past both first inlet 28 and second inlet 32 , for example, as shown in FIG. 3 with respect to second inlet 32 . During this movement, seal 62 , positioned on seal cover assembly 26 , will reach the position shown in FIG. 4 a, with respect to both first inlet 28 and second inlet 32 . As shown in FIG. 4 a, clearance gap 60 , formed between tip portion 48 and the wall of charging body 14 forming the respective inlet, communicates with a first cover clearance gap 74 formed on one side of seal 62 and a second cover clearance gap 76 extending from an opposite side of seal 62 . As a result, in conventional systems, when seal cover assembly 26 is in the position shown in FIG. 4 a relative to both first inlet 28 and second inlet 32 , a fluid flow path is created which disadvantageously causes MR fluid flow from MR fluid chamber 66 through cover clearance gap 74 , clearance gap 60 and cover clearance gap 76 into an outer chamber 78 . This leakage flow of MR fluid into outer chamber 78 creates a waste quantity of MR fluid, more difficult cleanup and thus increased cost since chamber 78 is open to the surrounding environment. The system and method of the present invention solves this leakage problem by energizing magnetic field generating assemblies 18 and 42 upon first inlet valve 16 and second inlet valve 38 being moved into the closed position after filling is complete and before pressing the components inwardly from the position shown in FIG. 1 b. The magnetorheological effect experienced by the MR fluid in clearance gap 60 of both first inlet 28 and second inlet 32 causes the MR fluid to increase in viscosity sufficiently to block fluid flow through clearance gap 60 . Accordingly, MR fluid leakage between chamber 66 and outer chamber 78 via clearance gap 60 is substantially eliminated. Also, after seal cover assembly 26 moves completely past first inlet 28 , magnetic flow generating assembly 18 remains energized so as to prevent leakage of MR fluid in clearance gap 60 from draining into outer chamber 78 both before and after the removal of press member 72 which occurs after completely displacing the components and fluid into damper cylinder 12 . Likewise, magnetic field generating assembly 42 preferably remains energized after seal cover assembly 26 passes second inlet 32 to prevent leakage of MR fluid in clearance 60 which entered clearance 60 as chambers 64 and 66 passed over clearance 60 .
In summary, the MR damper charging system 10 of the present invention effectively substantially minimizes MR fluid leakage during the MR damper assembly process thereby reducing costs associated with MR fluid consumption and MR fluid cleanup while avoiding environmental challenges associated with magnetorheological fluid spillage. In addition, the present MR damper charging system effectively eliminates the undesirable leakage of MR fluid into gas chamber 68 which is also undesirable.
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A novel and improved magnetorheological (MR) damper charging system is provided which simply and effectively substantially minimizes MR fluid leakage during a MR damper assembly process thereby minimizing cleanup and reducing costs. The damper charging system includes a charging body having a bore for receiving damper components and damper fluid, at least one inlet formed in the charging body for delivering fluid to the bore, and a magnetic field generating assembly mounted at the inlet and operable in an energized state to generate a magnetic field across the inlet to cause MR fluid in the inlet to experience a MR effect sufficient to prevent leakage flow through and from the inlet. An inlet valve is mounted on the charging body for controlling flow of fluid through the inlet into the bore. The magnetic field generating assembly is positioned to generate magnetic flux within a clearance gap between the valve and the inlet walls thereby blocking flow and preventing leakage through the clearance gap as the MR damper components move past the inlet.
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CROSS-REFERENCE TO RELATED APPLICATIONS
U.S. Pat. Nos. 6,046,343 and 6,300,505 are hereby incorporated by reference in their entireties.
This application is a divisional of U.S. Pat. No. 8,954,196, which is the National Phase of International Application PCT/US2009/057422 filed Sep. 18, 2009 which designated the U.S. and which claims priority to U.S. Provisional App. Ser. No. 61/099,726 filed Sep. 24, 2008. The noted applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of the present invention generally relate to temperature control of a reactor using probability distribution of temperature measurements.
2. Description of the Related Art
Maleic anhydride is of significant commercial interest throughout the world. It is used alone or in combination with other acids in the manufacture of alkyd and polyester resins. It is also a versatile intermediate for chemical synthesis.
Maleic anhydride is conventionally manufactured by passing a gas comprising a hydrocarbon having at least four carbon atoms in a straight chain and oxygen through a catalyst bed, typically a fixed catalyst bed tubular plug flow reactor, containing a catalyst including mixed oxides of vanadium and phosphorus. The catalyst employed may further comprise promoters, activators or modifiers such as iron, lithium, zinc, molybdenum, chromium, uranium, tungsten, and other metals, boron and/or silicon. The product gas exiting the reactor typically contains maleic anhydride together with oxidation by-products such as carbon monoxide, carbon dioxide, water vapor, acrylic and acetic acids and other by-products, along with inert gases present in air when air is used as the source of molecular oxygen.
Because the reaction is highly exothermic, the reactor must be cooled during operation. Typically, a shell and tube heat exchanger is used as a reactor with the catalyst packed in the tubes through which the hydrocarbon and oxygen gases are passed. A cooling fluid, often a molten salt, flows over and cools the outside of the tubes. Because the length of the tubes is generally much greater than the diameter of the tubes, the reaction system approaches plug flow.
While the cooling capacity is substantially uniform throughout the reactor, the rate of reaction varies widely with the concentration of the hydrocarbon reactant and the temperature of the reaction zone. Because the reactant gases are generally at a relatively low temperature when they are introduced into the catalyst bed, the reaction rate is low in the region immediately adjacent the inlet of the reactor. Once the reaction begins, however, it proceeds rapidly with the rate of reaction further increasing as the reaction zone temperature increases from the heat released by the reaction. The reaction zone temperature continues to increase with distance along the length of the reactor tube until the depletion of the hydrocarbon causes the rate of reaction to decrease thereby decreasing the temperature of the reaction zone through transfer of heat to the cooling fluid, and allowing the remaining portion of the reactor tube to operate at a lower temperature differential. In practice, commercial reactors are configured so that a number of tubes, typically 50-100+, are equipped with a longitudinal thermocouple in the center of the tube, inserted to a tube depth (distance from the top or bottom tubesheet) where maximum temperatures are expected. Of these multiple measurement locations, the location with the highest temperature is generally referred to as the “hot spot”.
If the temperature distribution in the reactor increases, reactor performance, catalyst activity, and the integrity of the reactor vessel may deteriorate. Generally, the selectivity of the catalyst varies inversely with the reaction temperature while the rate of reaction varies directly with the reaction temperature. Higher reaction zone temperatures result in lower catalyst selectivity and favor the complete oxidation of the hydrocarbon feedstock to carbon dioxide and water instead of maleic anhydride. As the temperature distribution in the reactor increases, the amount of the hydrocarbon feedstock consumed by the reaction increases but the decreased selectivity of the catalyst can result in a decreased yield of maleic anhydride. In addition, exposure of the catalyst bed to excessive temperatures may degrade the catalyst activity and cause and excessive rate of corrosion of the reactor tubes. Such degradation of the catalyst activity generally reduces the productivity of the operation and may also reduce the selectivity of the catalyst at a given temperature. The higher heat of reaction released by the conversion of the hydrocarbon feedstock to carbon dioxide and water further compounds this problem. An excessive rate of corrosion of the reactor tubes will lead to premature failure of individual tubes or of the entire reactor.
Typically, the catalyst bed temperature is continuously monitored at 50-100+ tubes via a single thermocouple at each location. The bulk of the catalyst bed is maintained below an upper temperature limit by reducing the feed rate of the limiting reactant (i.e., air or butane) if the “hot spot” is above the specified upper temperature limit.
SUMMARY OF THE INVENTION
Embodiments of the present invention generally relate to temperature control of a reactor using probability distribution of temperature measurements. In one embodiment, a method of controlling a temperature of a chemical reaction includes injecting a reactant stream into a reactor and through a catalyst bed of the reactor. The reactant stream includes a hydrocarbon and oxygen. Injection of the reactant stream into the catalyst bed causes an exothermic chemical reaction. The method further includes circulating a coolant through the reactor, thereby removing heat from the catalyst bed. The method further includes measuring temperature at a plurality of locations in the catalyst bed. The method further includes calculating a fraction of the catalyst bed greater than a predetermined maximum temperature limit using a probability distribution generated using the temperature measurements.
In another embodiment, a chemical reactor includes a tubular shell having an inlet and an outlet, each formed through a wall thereof. The reactor further includes three or more tubes disposed in the shell, made from a thermally conductive material, and containing catalyst. The reactor further includes first and second tube sheets, each tube sheet fixed to each of the tubes and coupled to the shell, thereby isolating bores of the tubes from a chamber of the reactor. The reactor further includes first and second heads coupled to the shell, each head having an inlet and an outlet formed through a wall thereof. The reactor further includes two or more temperature sensors, each temperature sensor disposed through the shell, into the bores of respective tubes, and in communication with the catalyst. The reactor further includes a controller in communication with the temperature sensors and configured to perform an operation. The operation includes inputting temperature measurements from the temperature sensors, and calculating a fraction of the catalyst greater than a predetermined maximum temperature limit using a probability distribution generated using the temperature measurements.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 is a cross-section of a reactor, according to one embodiment of the present invention.
FIG. 2 illustrates a comparison between three temperature control schemes: the Prior Art hot spot scheme, an Ideal scheme, and a scheme according to an embodiment of the present invention.
FIG. 3 illustrates another comparison between the Prior Art hot spot scheme and a scheme according to an embodiment of the present invention.
DETAILED DESCRIPTION
FIG. 1 is a cross-section of a reactor 1 , according to one embodiment of the present invention. The reactor 1 may include a tubular shell 3 , vertically oriented tubes 5 , a lower head 7 having a gas inlet 9 , and an upper head 11 having a gas outlet 13 . Tubes 5 of the reactor 1 may be fixed in lower 15 and upper 17 tube sheets and may be made from a thermally conductive material so that the reactor functions as a shell and tube heat exchanger. The tubes 5 may be packed with catalyst 19 only or catalyst with a temperature sensor 20 . The catalyst 19 may be solid particles, such as beads or pellets, and may be made from a material selected to facilitate a chemical reaction, such as vanadium-phosphorous-oxide (VPO). The columns of catalyst may be collectively referred to as a catalyst bed of the reactor 1 . A gas reactant stream HC+O 2 may be injected into the reactor 1 via the inlet 9 . The reactant stream HC+O 2 may include a first reactant, such as hydrogen or a hydrocarbon, such as a hydrocarbon having at least four carbon atoms in a straight chain, such as n-butane or benzene, and a second reactant, such as a gas having a substantial oxygen concentration, such as air.
As the reactant stream flows through the catalyst bed, an exothermic reaction may occur, thereby producing a gas product stream. The product stream may include a desired product, such as maleic anhydride and byproducts, such as inert gases, water, acetic acid, acrylic acid, carbon monoxide and carbon dioxide. The product stream may exit the reactor via the outlet 13 and may be further processed to separate the desired product from the byproducts. Alternatively, the reactant/product stream flow may be reversed. Alternatively, the desired product may be phthalic anhydride (PA), acrolein, methyl mercaptan, acrylic acid, butanediol, methanol, ethylene oxide, ethylene glycol, formaldehyde, hydrogenated vegetable oil or fat, or vinyl chloride monomer.
To remove heat energy from the exothermic reaction, a coolant may be injected into an inlet 21 formed through the shell. The coolant may circulate along outer surfaces of the tubes 5 , thereby removing heat energy. The coolant may discharge from the reactor at an outlet 23 where it may be cooled in an external heat exchanger 26 which is equipped with a flow control valve 27 , and recirculated via an external pump. Alternatively, coolant flow may be reversed. The coolant may be a liquid, such as molten salt or molten inorganic salt. The average or inlet temperature of the coolant may be controlled at a predetermined set temperature to maintain a stable average catalyst bed temperature.
To monitor the catalyst bed temperature, a plurality of temperature sensors 20 a, b may be disposed through respective openings formed in one of the heads 7 , 11 . The temperature sensors 20 a, b may be thermocouples, resistance temperature detectors (RTDs), thermistors, or optical fibers. The temperature sensors 20 a, b may extend into respective selective tubes 5 to sense temperatures in the tubes at various longitudinal heights. The temperature sensors may also be radially and tangentially dispersed throughout the reactor 1 . Commercial reactors may be sizable and have a multitude of tubes 5 , such as one thousand, ten thousand, twenty thousand, thirty thousand, or more tubes. To remain economically feasible, a number of temperature sensors that is a ratio to the number of tubes may be deployed, such as one temperature sensor for every one hundred, two hundred, three hundred, four hundred, or five hundred tubes. A single temperature sensor may contain several elements, such that more than one depth can be monitored within a single tube. The temperature sensors may be asymmetrically concentrated at various longitudinal heights. For example, in a maleic anhydride reactor, a majority of the reaction may occur at lower heights in the reactor and a correspondingly greater concentration of temperature sensors may extend to these heights.
Each of the temperature sensors 20 a, b may be in electrical or optical communication with a controller 25 . The controller 25 may be a microprocessor based computer and may be located in a control room (not shown). The controller may include a video screen for displaying temperature measurements to a human operator.
As discussed above, the prior art control scheme dictates remedial action if any one of the thermocouples, such as the “hot spot”, detects a temperature exceeding a predetermined maximum temperature limit. Due to the high variability associated with the “hot spot” temperature, there are times when reactant feed rate (and production) is curtailed when there has been no actual shift in the bed temperature distribution. Conversely, there are other times when the bed temperature distribution has shifted, causing a higher fraction of the bed to be above the maximum limit, and the maximum temperature does not detect this shift. The maximum bed temperature is a fairly unreliable indication of the true bed temperature distribution and the true fraction of the bed above a specified upper limit.
To overcome these shortcomings, the controller 25 may analyze the temperature measurements (T c ) from the temperature sensors 20 a, b , using a probability distribution as opposed to simply determining the maximum, thereby more accurately estimating a temperature profile of the catalyst bed. The probability distribution may be based on the theory that differences (ΔT) between each of the catalyst bed temperatures in the reaction zone (T c ) and the catalyst bed temperature (θ) adjacent the inlet may be distributed lognormally. This theory has been verified by statistical analysis of a maleic anhydride reactor. An additional temperature sensor may be used to obtain the catalyst bed temperature (θ) adjacent the inlet or the control temperature of the coolant may be used as a convenient approximation thereof. Let N(T c >T mx ) represent the number of thermocouples which exceed the maximum temperature limit (T mx ) and N(T c ) represent the total number of thermocouples. The controller may calculate a fraction
( F ( Bed > T mx ) = N ( T C > T mx ) N ( T C ) )
of the reactor bed greater than a maximum temperature limit (T mx ) using the lognormal probability distribution (LNPDF) of the temperature differences (ΔT). The calculated fraction of the reactor bed may then be compared to a predetermined maximum fraction to more accurately asses whether the reactor is operating within acceptable limits. If not, then the remedial action may be taken.
For example, the controller may be programmed to perform an operation. The operation may include inputting temperature measurements (T c ) from each temperature sensor 20 a, b within the catalyst bed. The operation may further include subtracting the coolant control temperature (as an approximation of θ) from each temperature measurement (T c ) to obtain a temperature difference (ΔT=T c −θ) and from the maximum temperature limit (T mx ) to obtain a maximum temperature limit difference (ΔT mx =T mx −θ). The operation may further include calculating the natural logarithm of each temperature difference (ln(ΔT)). The operation may further include calculating the average (μ(ln(ΔT))) and standard deviation (σ(ln(ΔT))) of the natural logarithm of each temperature difference (ln(ΔT)). The operation may further include generating a lognormal probability density function (LNPDF) using the calculated average and standard deviation of the natural logarithm of each temperature difference. The operation may further include estimating an integral (i.e., using an iterative numerical approximation) of the lognormal probability density function. The integral may be integrated from a first limit, such as the maximum temperature limit difference, to a second limit, such as infinity, to obtain the fraction of the catalyst best greater than the maximum temperature limit:
F
(
Bed
>
T
mx
)
=
∫
Δ
T
mx
∞
LNPDF
(
Δ
T
,
μ
,
σ
)
ⅆ
Δ
t
=
∫
Δ
T
mx
∞
1
σ
2
π
ⅇ
-
(
ln
(
Δ
T
)
-
μ
)
2
2
σ
2
ⅆ
Δ
T
The controller may then compare the fraction of the bed which exceeds the specified temperature maximum to a predetermined maximum fraction. If the calculated fraction is greater than the maximum fraction, the controller may automatically take remedial action, such as reducing the flow rate of the reactant stream. Alternatively, the controller may take remedial action if the calculated fraction is proximate to or equal to the maximum fraction. Alternatively, the controller may provide indication, such as an audio and/or visual alarm, to a human operator who may then take remedial action. If the calculated fraction is less than the maximum fraction, then the process may continue unabated or the reactant stream flow rate may even be increased, especially if the calculated fraction is substantially less than the maximum fraction. The controller may repeat the operation every interval of time, such as every five seconds, one second, one-half second, one-tenth second, one-hundredth or one-thousandth second. Alternatively, the PDF may be a logarithm of any base greater than zero and not one, such as ten.
The maximum temperature limit may depend on the specific reactants and/or catalyst used in the reactor. For example, a maximum temperature limit for a maleic anhydride reactor may be from about 300 to about 550 degrees Celsius or to about 500 degrees Celsius. The maximum fraction may also depend on the specific reactants, catalyst used in the reactor, and/or the age of the catalyst. For example, in a maleic anhydride reactor using a catalyst having a lifespan of three to four years, the maximum fraction of the catalyst bed which is at or above the maximum temperature limit may range from zero to three percent during a first half of the lifespan and then be increased to three to four percent for a second half of the lifespan.
FIG. 2 illustrates a comparison between three temperature control schemes: the Prior Art hot spot scheme, an Ideal scheme, and a scheme 200 according to an embodiment of the present invention. These curves were created by a Monte Carlo simulation of a maleic anhydride reactor having 31,000 to 35,000 tubes and 108 thermocouples in the catalyst bed and having a maximum temperature limit of 500 degrees Celsius and a maximum fraction of one percent.
In the Ideal control scheme, there is no inaccuracy, such that when the true percentage of the bed greater than 500 degrees Celsius is less than one percent, the control scheme detects the acceptable condition with absolute certainty. Conversely, when the true percentage of the bed greater than 500 degrees Celsius is greater than one percent, the Ideal control scheme detects the unacceptable condition with absolute certainty. Thus the Ideal Control scheme is a step function.
Referring now to the Prior Art scheme and the Embodiment 200 , the Embodiment 200 is generally closer to the Ideal scheme than the Prior Art scheme. For example, when the true percentage of the bed greater than 500 degrees Celsius is one-half percent, the probability that the Prior Art scheme will falsely indicate that the maximum fraction has been exceeded is about 45%, as compared to 10% for the Embodiment 200 . The exception in the one to one and one-half percent range where the Prior Art scheme enjoys an advantage in accuracy as compared to the Embodiment 200 is not significant due to generosity in safety factors. The Embodiment 200 significantly reduces risk of production and sales loss which occurs when the true fraction of the bed is less than the maximum fraction but the Prior Art scheme falsely indicates otherwise. Conversely, the Embodiment 200 provides greater protection against unknowingly operating the reactor with an excessive fraction of the bed above the upper temperature limit. FIG. 2 assumes 108 thermocouples are present. As the number of thermocouples increases, the Embodiment 200 will be closer to the Ideal scheme.
FIG. 3 illustrates another comparison between the Prior Art hot spot scheme and a scheme 200 according to an embodiment of the present invention. As with FIG. 2 , these curves were created by a Monte Carlo simulation of a maleic anhydride reactor having 31,000 to 35,000 tubes and 108 thermocouples in the catalyst bed and having a maximum temperature limit of 500 degrees Celsius and a maximum fraction of one percent. The actual fraction of the catalyst bed at a temperature greater than 500 degrees Celsius was set at one-tenth percent. Each control scheme was repeated for 1,000 observations (or intervals of time). The Prior Art scheme falsely detected an unacceptable condition a total of 93 times, as compared to 2 or 3 times for the Embodiment 200 . The false detections translate to a reduction in production and sales during 9.3% of the operating time for the Prior Art scheme, as compared to two-tenths of a percent for the Embodiment 200 .
Additional advantages may be realized from one or more embodiments of the present invention. The mean or average of the lognormal distribution is a measure of the heat transfer coefficient in the reactor and may be useful in comparing heat removal performance between reactors, thereby identifying the causes of poor reactor heat transfer. The standard deviation of the lognormal distribution is a measure of tube to tube variability in a given reactor and may be useful in identifying differences between reactors with respect to tube to tube variation in reactant stream composition and flow rate. For example, one maleic reactor having an increased ratio of thermocouples required a reduction in reactant stream flow rate. The initial diagnosis of the reactor was a problem with the reactor. However, upon implementing an embodiment of the present invention, the problem was identified as an increase in false alarms due to the Prior Art scheme used with the increased ratio of thermocouples and not the reactor itself.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
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Embodiments of the present invention generally relate to temperature control of a reactor using probability distribution of temperature measurements. In one embodiment, a method of controlling a temperature of a chemical reaction includes injecting a reactant stream into a reactor and through a catalyst bed of the reactor. The reactant stream includes a hydrocarbon and oxygen. Injection of the reactant stream into the catalyst bed causes an exothermic chemical reaction. The method further includes circulating a coolant through the reactor, thereby removing heat from the catalyst bed. The method further includes measuring temperature at a plurality of locations in the catalyst bed. The method further includes calculating a fraction of the catalyst bed greater than a predetermined maximum temperature limit using a probability distribution generated using the temperature measurements.
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BACKGROUND OF THE INVENTION
The present invention relates to a process for preparing intermediates useful in the preparation of benzazepines having activity as selective D1 receptor antagonists.
U.S. Pat. No. 4,973,586 discloses fused benzazepines, and in particular the compound known as SCH 39166, having the structure ##STR4## as selective D1 antagonists useful in the treatment of psychoses, depression, pain and D1 dependent neurological disorders. Methods for preparing such compounds are also described therein.
Berger, et al, J. Med. Chem., 2, 1913-1921 (1989), discloses a process for preparing SCH 39166 comprising acid promoted cyclization of a compound of the formula (1) to give a 1:1 mixture of cis and trans benzazepines (cis-2 and trans-2, respectively). Compound trans-2 is then converted to racemic compound I via a multi-step procedure. Compound I is resolved via its di-O,O'-p-tolyltartrate salt and hydrolyzed with HBr and HOAc to give SCH 39166. ##STR5## The prior art process suffers from several shortcomings. It is inefficient, producing a 1:1 mixture of cis and trans benzazepines in the cyclization step. In addition, conducting the resolution step at a late stage of the synthesis is very costly and adds further inefficiency. Therefore, it was desirable to develop a chemically efficient and cost effective process for preparing SCH 39166 of high optical purity. It was also desired that the resolution be performed at an early stage of the process or that the chiral centers be introduced using inexpensive chiral starting materials, thereby avoiding the need for resolution.
SUMMARY OF THE INVENTION
The present invention comprises a process for preparing a compound of the formula I ##STR6## comprising the steps: (a) Reacting an aziridinium salt of the formula ##STR7## wherein Q is a group of the formula ##STR8## wherein R is C 1 -C 6 alkyl, and X - is a counterion, with a reagent of the formula ##STR9## wherein M is selected from MgL, ZnL, TiL 3 , CeL 2 , MnL or CuL, and L is a halide selected from Br, Cl or I; to form a compound of the formula ##STR10## wherein Q is as defined above; and (b) cyclizing the product of step (a).
The present invention further comprises a process, designated Process A, wherein the aziridinium salt of step (a) is prepared, as a racemate or a single enantiomer, by a process comprising the steps:
(A1) epoxidizing 1,2-dihydronaphthalene to form an epoxide of the formula ##STR11## as a racemate by reacting with: (i) H 2 O 2 in the presence of a base; or as a single enantiomer by reacting with:
(ii) NaOCl in the presence of Mn(III) salen catalyst; or
(iii) O s O 4 in the presence of NMMO and dihydroquinine 4-chlorobenzoate, followed by treating the resulting cis diol with (C 6 H 5 ) 3 PBr 2 in the presence of a tertiary amine base;
(A2) regioselectively reacting the epoxide of step (A1) with CH 3 NH 2 to form an aminoalcohol of the formula ##STR12## (A3) N-alkylating the aminoalcohol of step (A2) with a compound of the formula J--CH 2 --Q, wherein J is a leaving group, and Q is as defined above; and
(A4) cyclizing the product of step (A3) by treating with an alkyllithium reagent and a sulfonyl chloride.
In an alternative embodiment, the present invention further comprises a process, designated Process B, wherein the aziridinium salt of step (a) is prepared in optically active form by a process comprising the steps:
(B1) Reacting S-(+)-2-amino-4-phenylbutanoic acid with ClCO 2 R 2 to form a carbamate of the formula ##STR13##
wherein R 2 is benzyl or C 1 -C 6 alkyl;
(B2) reacting the carbamate of step (B1) with a chlorinating agent, then cyclizing the resulting acid chloride by treating with a Lewis acid to form a ketone of the formula ##STR14## wherein R 2 is as defined above; (B3) reducing the ketone of step (B2) by reacting with a hydride reducing agent to form a compound of the formula ##STR15## (B4) reacting the product of step (B3) with a compound of the formula J--CH 2 --Q, wherein J and Q are as defined above; and
(B5) cyclizing the product of step (B4) by treating with an alkyllithium reagent and a sulfonyl chloride.
In a second alternative embodiment, the present invention further comprises a process, designated Process C, wherein the aziridinium salt of step (a) is prepared by a process comprising the steps:
(C1) converting 1,2-dihydronaphthalene to an epoxide of the formula ##STR16## by the process of step (A1); (C2) reacting the epoxide of step (C1) with an amine of the formula HN(R 1 )--CH 2 --Q, wherein R 1 is H or CH 3 , and Q is as defined above, to form an amino alcohol of the formula ##STR17## (C3) (I) where R 1 is H, cyclizing the product of step (C2) to form an aziridine of the formula ##STR18## by reacting with: (i) (C 6 H 5 ) 3 PBr 2 ; or
(ii) mesyl chloride or tosyl chloride in the presence of a tertiary amine base;
followed by N-methylating the resulting aziridine by treating with:
(iii) CF 3 SO 3 CH 3 ; or
(iv) (CH 3 ) 3 OBF 4 ; or
(II) where R 1 is CH 3 , cyclizing the product of step (C2) by treating with an alkyllithium reagent and a sulfonyl chloride.
In a third alternative embodiment, the present invention further comprises a process, designated Process D, wherein the aziridinium salt of step (a) is prepared in optically active form by a process comprising the steps:
(D1) resolving a trans-amine of the formula ##STR19## by treating with L-(+)-tartaric acid in an alcohol solvent to form the tartrate salt, recrystallizing the tartrate salt from an alcohol solvent, then treating the tartrate salt with base to form a chiral amine of the formula ##STR20## (D2) reacting the chiral amine of step (D1) with a compound of the formula J--CH 2 --Q, wherein J and Q are as defined above, in the presence of a base to form a compound of the formula ##STR21## (D3) cyclizing the product of step (D2) by treating with an alkyllithium reagent and a sulfonyl chloride.
Preferred is a process wherein: Q is--CH(OCH 3 ) 2 ; the counterion X - is Cl - , BF 4 - , CH 3 C 6 H 4 SO 3 - , C 6 H 5 SO 3 - , CH 3 SO 3 - or CF 3 SO 3 - ; M is MgBr; and the cyclization of step (b) is carried out by treating with a strong acid, followed by treatment with a hydride reducing agent, preferably BH 3 .tBuNH 2 or NaBH 4 .
Also preferred is a process according to Process A wherein: the base of step (A 1 )(i) is NaHCO 3 or KHCO 3 ; the tertiary amine base of Step (A1)(iii) is Et 3 N; in Step (A3) J is Br; the alkyllithium reagent of Step (A4) is n-butyllithium; and the sulfonyl chloride of Step (A4) is tosyl chloride, nosyl chloride, brosyl chloride, benzene sulfonyl chloride or mesyl chloride.
Another preferred process is a process according to Process B wherein: the chlorinating agent of step (B2) is oxalyl chloride or SOCl 2 ; the Lewis acid of step (B2) is AlCl 3 ; the hydride reducing agent of step (B3) is LiAlH4; in Step (B4) J is Br; the alkyllithium reagent of Step (B5) is n-butyllithium; and the sulfonyl chloride of Step (B5) is tosyl chloride, nosyl chloride, brosyl chloride, benzene sulfonyl chloride or mesyl chloride.
Yet another preferred process is a process according to Process C wherein: the tertiary amine base of step (C3)(ii) is Et 3 N; the alkyllithium reagent of Step (C3)(II) is n-butyllithium; and the sulfonyl chloride of Step (C3)(II) is tosyl chloride, nosyl chloride, brosyl chloride, benzene sulfonyl chloride or mesyl chloride.
Still another preferred process is a process according to Process D wherein the alcohol solvent of step (D1) is methanol; the base of step (D2) is NH 4 OH, Na 2 CO 3 or K 2 CO 3 ; J is Br; the alkyllithium of step (D3) is n-butyllithium; and the sulfonyl chloride of Step (D3) is tosyl chloride, nosyl chloride, brosyl chloride, benzene sulfonyl chloride or mesyl chloride.
The process of the present invention does not suffer the shortcomings of the prior art processes. It is chemically efficient and, by utilizing inexpensive chiral starting materials, or by utilizing enantioselective transformations on prochiral compounds, or alternatively by performing a resolution step at an early stage of the synthesis, produces a chiral product (compound I) which is readily converted to SCH 39166 by known methods.
The present invention further comprises compounds of the formula ##STR22## wherein: X - is halide, BF 4 - or R 3 SO 3 - , wherein R 3 is C 1 -C 6 alkyl, CF 3 , benzyl, phenyl or Z-substituted phenyl, wherein Z is C 1 -C 6 alkyl, nitro or bromo; and Q is a group of the formula ##STR23## wherein R is C 1 -C 6 alkyl, useful as intermediates in the preparation of benzazepines having activity as selective D1 receptor antagonists. Preferably such compounds have the absolute stereochemistry shown in the formula ##STR24##
The present invention also comprises compounds of the formula ##STR25## wherein Q is a group of the formula ##STR26## wherein R is C 1 -C 6 alkyl, useful as intermediates in the preparation of benzazepines having activity as selective D1 receptor antagonists. Preferably such intermediates have the absolute stereochemistry shown in the formula ##STR27##
In another embodiment, the present invention comprises chiral compounds of the formula ##STR28## wherein R 1 is H or CH 3 ; and Q is a group of the formula ##STR29## wherein R is C 1 -C 6 alkyl, useful as intermediates in the preparation of benzazepines having activity as selective D1 receptor antagonists.
DETAILED DESCRIPTION
In general, stereochemical representations are meant to denote relative stereochemistry. However, where optically active starting materials are employed, such as in the embodiment denoted as process B, the stereochemical representations denote absolute as well as relative stereochemistry. Therefore, by using such optically active starting materials, compounds of the formula I can be prepared as a single enantiomer. Similarly, by utilizing stereoselective transformations on prochiral compounds to generate chiral compounds, or by performing a resolution step (such as in Process D), a single enantiomer of compounds of the formula I is produced.
In those embodiments where the present invention relates to chiral compounds, the stereochemical purity of such compounds is generally given in terms of the enantiomeric excess (e.e.).
As used herein the term "alkyl" means a straight or branched alkyl chains of 1 to 6 carbon atoms;
"tertiary amine base" means a tertiary amine selected from pyridine, di-isopropylethylamine or a tri-(C 1 -C 6 alkyl)amine, such as triethylamine;
"base" means a water soluble base, such as NH 4 OH, KHCO 3 , K 2 CO 3 , NaHCO 3 or Na 2 CO 3 ;
"strong base" means an alkali metal hydroxide, such as NaOH, KOH or LiOH, or an alkaline earth metal hydroxide such as Ca(OH) 2 ;
"leaving group" means a group which can be readily displaced by a nucleophile, preferably --Cl, --Br, --l, --OSO 2 CH 3 , --OSO 2 CF 3 or --OSO 2 C 6 H 4 CH 3 ;
"sulfonyl chloride" means a compound of the formula R 3 SO 2 Cl, wherein R 3 is C 1 -C 6 alkyl, CF 3 , benzyl, phenyl or Z-substituted phenyl, and Z is C 1 -C 6 alkyl, nitro or bromo, with preferred sulfonyl chlorides including tosyl chloride, nosyl chloride, mesyl chloride, brosyl chloride and benzene sulfonyl chloride;
"alkyllithium" means an alkyllithium reagent, such as n-butyllithium, methyllithium, sec-butyllithium or tert-butyllithium;
"strong acid" means a protic acid having a pKa<2, such as H 2 SO 4 or CH 3 SO 3 H;
"Lewis acid" means a Lewis acid capable of catalyzing a Friedel-Crafts type reaction, such as AlCl 3 ;
"hydride reducing agent" means a metal hydride reducing agent, such as NaBH 4 , NaBH 3 CN, LiBH 4 or LiAlH 4 , or a borane amine complex, such as borane-methylamine, borane-tert-butylamine, borane-piperidine, borane-triethylamine, borane-N,N-diisopropylethylamine, borane-N,N-diethylaniline, borane-morpholine, borane-4-ethylmorpholine or borane-4-phenylmorpholine complex;
"counterion" means an anion selected from a halide, BF 4 - , and R 3 SO 3 - , wherein R 3 is C 1 -C 6 alkyl, CF 3 , C 1 -C 6 alkylphenyl, benzyl, nitrophenyl, bromophenyl or phenyl; and
"halide" means a chloride, bromide, fluoride or iodide anion.
As used herein the following reagents and solvents are identified by the abbreviations indicated: para-toluenesulfonyl chloride (tosyl chloride, TsCl); para-bromobenzenesulfonyl chloride (brosyl chloride); para-nitrobenzenesulfonyl chloride (nosyl chloride); N-methylmorpholine-N-oxide (NMMO); methanesulfonyl chloride (mesyl chloride, MsCl); tetrahydrofuran (THF); iso-propanol (i-PrOH); methanol (MeOH); ethyl acetate (EtOAc); tert-butyl methyl ether (TBME); borane-tert-butylamine complex (BH 3 .tBuNH 2 ); triethylamine (Et 3 N); chloro[[2,2'-[1,2-cyclohexane-diylbis(nitrilomethylidyne)]bis[4,6-bis(1,1-dimethyl-ethyl)phenolato]](2-)-N, N', O,O'-manganese (Mn(III) salen catalyst); trifluoroacetic acid (TFA).
The aziridinium salts of step(a) of the process of the present invention exist in conjunction with a counterion identified as X - . The counterion is a suitable anion such as halide, BF 4 - or R 3 SO 3 - , wherein R 3 is C 1 -C 6 alkyl, CF 3 , C 1 -C 6 alkylphenyl, benzyl, nitrophenyl, bromophenyl or phenyl.
The present invention comprises a process for preparing a compound of the formula I as shown in Reaction Scheme 1. The stereochemical representations depict the preferred stereoisomers. The process can be carried out using a racemic aziridinium salt, in which case the stereochemical representations designate the preferred isomers having the relative stereochemistry shown. Alternatively, the process can utilize a single enantiomeric aziridinium salt to produce a single enantiomer of compound I, wherein the stereochemical representations further designate absolute stereochemistry. ##STR30##
In Scheme 1, Step (a), a Grignard reagent (III), wherein M is MgBr, is prepared from 5-bromo-2-chloroanisole and Mg in a suitable solvent, such as THF, at -10° to 60° C., preferably at 40° to 45° C., then reacted with the aziridinium salt (II) in a suitable solvent, such as THF, at -80° to 0° C., preferably at -30° to -20° C., for 1 to 10 hours, preferably about 5 hours, then at 0° to 70° C., preferably about 25° C., to form a compound of the formula IV, wherein Q is as defined above.
Alternatively, in Step (a) the aziridinium salt (II) is treated (under substantially the same conditions as described for the Grignard reagent) with a reagent (III) wherein M is ZnL, TiL 3 , CeL 3 , MnL or CuL, and L is a halide ligand selected from Br, Cl or I. Where more than one such ligand L is present the individual ligands can be the same or different;
In Step (b), compound IV, wherein Q is --CH(OR) 2 and R is as defined above, is combined with a strong acid, such as CH 3 SO 3 H, in a suitable solvent, such as CH 2 Cl 2 , at -30° to +20° C., preferably 0° to +5° C., then warmed to 20° to 60° C., preferably about 40° C. The resulting mixture is concentrated by warming at 30° to 60° C., preferably about 50° C., under reduced pressure, and the residue is dissolved in a suitable solvent, such as CH 2 Cl 2 , then treated with a hydride reducing agent, preferably NaBH 4 , and an alcohol solvent, preferably isopropanol, to give a compound of the formula I.
Alternatively, in Step (b), compound IV, wherein Q is --CH(OR) 2 and R is as defined above, is combined with a strong acid, such as H 2 SO 4 , in a suitable solvent, such as CH 2 Cl 2 , at -20° to +20° C., preferably 0° to +5° C., then warmed to 10° to 60° C., preferably about 25° C. The mixture is cooled to -20° to +20° C., preferably about 0° C., then treated with a hydride reducing agent, preferably BH 3 .tBuNH 2 , and warmed to 10° to 60° C., preferably about 25° C., to give a compound of the formula I.
The present invention further comprises a process as described above wherein the aziridinium salt of Step (a) is prepared according to Process A, as shown in Reaction Scheme A. ##STR31##
In Reaction Scheme A, Step A1, 1,2-dihydronaphthalene (V) is treated with H 2 O 2 , preferably 30% H 2 O 2 (aqueous), and a base, preferably KHCO 3 or NaHCO 3 , in a suitable solvent, such as a mixture of CH 3 CN and an alcohol solvent, preferably CH 3 CN and MeOH, at 0° to 50° C., preferably at 25° to 30° C., for 2 to 24 hours, preferably about 17 hours, to form the racemic epoxide VI.
Alternatively, 1,2-dihydro-naphthalene (V) is converted to a single enantiomer of the epoxide VI as described in Step C1 of Method C.
In Step A2, the epoxide VI is reacted with CH 3 NH 2 in a suitable sealed container, preferably a teflon® lined bomb, at 50° to 130° C., preferably at 80° to 110° C., and most preferably about 100° C., for 12 to 36 hours, preferably about 22 hours, to form the aminoalcohol VII.
Alternatively, in Step A2, the epoxide VI is reacted with an excess of 40% CH 3 NH 2 (aqueous) at 0° to 50° C., preferably about 25° C., for 12 to 36 h, preferably about 24 h, to form the aminoalcohol VII. The reaction is carried out via substantially the same procedure as described in Crabb, et al., Mag. Res. in Chem., 24, 798 (1986) and Lukes, et al., Coil. Czech. Chem. Comm., 25, 492 (1960).
In Step A3, compound VII is combined with a compound of the formula J--CH 2 --Q, wherein J and Q are as defined above, in a suitable solvent, such as CH 3 CN or DMF, in the presence of a base, preferably Na 2 CO 3 or K 2 CO 3 , and the resulting mixture heated at 30° to 100° C., preferably at reflux, for 1 to 8 days, preferably about 6 days, to form compound VIII.
In Step A4, compound VIII is treated with an alkyllithium, preferably n-butyllithium, in a suitable solvent, such as anhydrous THF, at -60° to +20° C., preferably about 0° C., for about 10 minutes. The resulting mixture is then treated with a sulfonyl chloride, preferably tosyl chloride, at -20° to +20° C., preferably about 0° C., for about 15 minutes to form the aziridinium salt II, wherein Q is as defined above, and X - is R 3 SO 3 - , wherein R 3 is as defined above, which is used directly in Step (a) above.
In an alternative embodiment, the present invention further comprises a process as described in Reaction Scheme 1 wherein a single enantiomer of the aziridinium salt of Step (a) is prepared according to Process B as shown in Reaction Scheme B. ##STR32##
In Reaction Scheme B, Step B1, a combination of the chiral amino acid IX, a strong base, preferably NaOH, most preferably 1N aqueous NaOH, and a base, preferably Na 2 CO 3 , at -20° to +20° C., preferably about 0° C., is treated with ClCO 2 R 2 , wherein R 2 is as defined above, preferably CH 3 , then warmed to 0° to 40° C., preferably about 25° C., for 1 to 5 hours, preferably about 3 hours, then treated with HCl to form the carbamate X.
In step B2, the carbamate X is combined with a chlorinating agent, such as SOCl 2 or oxalyl chloride, preferably SOCl 2 , in a suitable solvent, such as CH 2 Cl 2 , and heated at 30° to 70° C., preferably at reflux, for 1 to 10 hours, preferably about 3 hours, then cooled to about 25° C. The resulting mixture is treated with a Lewis acid, preferably AlCl 3 , in a suitable solvent, such as CH 2 Cl 2 , for 1 to 10 hours, preferably about 3 hours, to give the ketone of the formula XI.
In Step B3, the ketone XII is treated with a hydride reducing agent, preferably LiAlH 4 , in a suitable solvent, such as THF, at -60° to 20° C., preferably about 0° C., for about 1 hour, then heated at 30° to 80° , preferably at reflux, for 1 to 10 hours, preferably about 2 hours, to form a compound of the formula XII.
In Step B4, compound XII is treated with a compound of the formula J--CH 2 --Q, wherein J and Q are as defined above, in a suitable solvent, such as CH 3 CN, in the presence of K 2 CO 3 , Na 2 CO 3 or KF and alumina, and the resulting mixture heated at 40° to 120° C., preferably at reflux, for 1 to 4 days, preferably about 2 days, to form compound XIII.
In Step B5, compound XIII is treated with an alkyllithium, preferably n-butyllithium, in a suitable solvent, such as THF, at -60° to +20° C., preferably about 0° C., for about 10 minutes. The resulting mixture is then treated with a sulfonyl chloride, preferably tosyl chloride, at -20° to +20° C., preferably about 0° C., for about 15 minutes to form a single enantiomer of the aziridinium salt II, wherein Q is as defined above, X 31 is R 3 SO 3 - , wherein R 3 is as defined above, and wherein the absolute stereochemistry is as shown in Reaction Scheme B, which is used directly in Step (a) of Reaction Scheme 1 above.
In a second alternative embodiment, the present invention further comprises a process as described in Reaction Scheme 1 wherein the aziridinium salt of Step (a) is prepared according to Process C as shown in Reaction Scheme C. ##STR33##
In Reaction Scheme C, Step C1: 1,2-dihydronaphthalene (V) is converted to the racemic epoxide VI as described above for Step A1 of Method A.
Alternatively, 1,2-dihydronaphthalene (V) is treated with OsO 4 and NMMO in a suitable solvent, such as a mixture of acetone and water, at -60° to +20° C., preferably at about 0° C., for 10 to 48 hours, preferably about 26 hours, to give cis-1,2,3,4-tetrahydro-1,2-napthalenediol. The treatment with OsO4 and NMMO can optionally be carried out in the presence of hydroquinine 4-chlorobenzoate, as described in Sharpless, et al, J. Org. Chem., 57, 2768-2771 (1992), in which case predominantly one enantiomer of the cis-diol is produced. The diol is treated with (C 6 H 5 ) 3 PBr 2 in the presence of a tertiary amine base, preferably triethylamine, in a suitable solvent, such as CH 3 CN, at 0° to 50° C., preferably at about 25° C., for 10 to 30 hours, preferably about 20 hours, to form predominantly one enantiomer of the epoxide VI, having the absolute stereochemistry indicated in Reaction Scheme C.
In another alternative, 1,2-dihydronaphthalene (V) is treated with NaOCl, preferably an aqueous solution of NaOCl, and a suitable manganese catalyst, preferably chloro[[2,2'-[1,2-cyclohexanediylbis(nitrilomethylidene)]bis[4,6-bis(1,1-dimethylethyl)phenolato]](2-)-N,N',O,O'-manganese, as described in Zhang, et al, J. Org. Chem., 56 2296-2298 (1991). The reaction is carried out in a suitable solvent, such as CH 2 Cl 2 , in the presence of 4-phenylpyridine N-oxide, at -60° to +20° C., preferably at about 0° C., for 30 to 90 minutes, preferably about 45 minutes, to form the chiral epoxide VI, 90% e.e., having the absolute stereochemistry indicated in Reaction Scheme C.
The epoxide VI can also be obtained as a single stereoisomer from commercial sources for use in Step C2.
In Step C2, the epoxide VI is treated with an amine of the formula Q--CH, 2 --NH(R 1 ), wherein Q and R 1 are as defined above, in a sealed container, preferably in a Teflon® lined bomb, at 60° to 120° C., preferably at about 95° C., for 10 to 48 hours, preferably for 20 to 24 hours, to form compound XIV.
In Step C3 (I), compound XIV, wherein R 1 is H, is reacted with (C 6 H 5 ) 3 PBr 2 and a tertiary amine base, preferably triethylamine, in a suitable solvent, such as CH 3 CN, at -40° to +20° C., preferably at about 0° C., for 1 to 2 hours, preferably about 90 minutes to form the aziridine XV. Alternatively, compound XIV is converted to the aziridine XV by treating with MsCl or TsCl and a tertiary amine base, preferably triethylamine, in a suitable solvent. Aziridine XV is reacted with (CH 3 ) 3 OBF 4 in a suitable solvent, such as CH 2 Cl 2 , at -60° to 0° C., preferably at about -20° C., for 10 to 30 hours, preferably about 20 hours, to form the aziridinium salt II, wherein X - is BF 4 - . Alternatively, the aziridine XV is treated with CF 3 SO 3 CH 3 in a suitable solvent, such as THF, at 0° to 50° C., preferably at about 25° C., for 10 to 60 minutes, preferably about 20 minutes, to form the aziridinium salt II, wherein X - is CF 3 SO 3 - .
In Step C3 (II), compound XIV is converted to the aziridinium salt II as described for Step A4 of Method A.
In a third alternative embodiment, the present invention further comprises a process as described in Reaction Scheme 1 wherein a single enantiomer of the aziridinium salt of Step (a) is prepared according to Process D as shown in Reaction Scheme D. ##STR34##
In Reaction Scheme D, In Step D1, the racemic transamine VII is treated with L-(+)-tartaric acid in a alcohol solvent, preferably methanol, at 0° to 50° C., preferably about 20° C., to form a solution of the tartrate salt. The tartrate salt solution is cooled to -20° to +20° C., preferably about -5° C., to give the crystalline tartrate salt. The tartrate salt is dissolved in an alcohol solvent, preferably methanol, at 30° to 100° C., preferably at reflux temperature, then cooled to -20° to +20° C., preferably about -5° C., to give the recrystallized tartrate salt. The recrystallized tartrate salt is treated with a base, preferably 10% NH 4 OH (aqueous) to give the amine (+)-VII as a single enantiomer.
In Step D2, the amine (+)-VII is converted to a single enantiomer of compound VIII via the process described for Step A3 of Reaction Scheme A.
In Step D3, compound VIII is converted to the aziridinium salt II as described for Step A4 of Reaction Scheme A.
Starting compounds of the formula V, IX and XVIII are commercially available. Compounds of the formula J--CH 2 --Q are commercially available or can be prepared via known methods, such as the methods described by Gribble, et al, in J. Org. Chem., 46, 2433-2434 (1981). Compounds of the formula VII can be prepared as described above or by Process E as shown in Reaction Scheme E. ##STR35##
The conversion of XVIII to VII is carried out via substantially the same procedures as described by: Braun, et al., Chem Berichte, 54, 597 (1921); Braun, et al., Chem Berichte, 55, 3648 (1922); and Lukes, et al., Coil. Czech. Chem. Comm., 492 (1960).
In Step E1, 1,2,3,4-tetra-hydronaphthalene XVIII is treated with Br 2 at 60° to 110° C., preferably about 90° C., to form the racemic trans-dibromide XVI.
Alternatively, in Step E 1, a solution of compound XVIII in hexane is treated with Br 2 at 40° C. to 100° C., preferably at reflux temperature, to form the racemic trans-dibromide XVI.
In Step E2, the dibromide XVI is combined with a mixture of acetone, water and a base, preferably NaHCO 3 , and heated at 40° to 100° C., preferably at reflux temperature, for 1 to 6 h, preferably about 3 h, to form the racemic trans-alcohol XVII.
In Step E3, the alcohol XVII is reacted with a 40% solution of CH 3 NH 2 in water at 0° to 50° C., preferably about 20° C., for 10 to 30 h, preferably about 16 h, to form the racemic trans-amine VII.
The following examples illustrate the process of this invention:
PREPARATION 1 ##STR36##
Combine Mg turnings (1.30 g, 54.00 mmol) and 35 mL dry THF. Add a solution of 5-bromo-2-chloroanisole (11.78 g, 53.20 mmol) dissolved in 300 mL dry THF over a 10 min. period, maintaining the reaction temperature at 40°-45° C., and stir for 90 min. The resulting solution of Grignard reagent is used as is.
PREPARATION 2 ##STR37## Step (a): ##STR38##
Combine hydroquinine 4-chlorobenzoate (5.00 g, 10.753 mmol), NMMO (7.57 g, 64.636 mmol) and 44 mL of a 10:1 acetone/water solution, stir vigorously and add OsO 4 (0.35 mL, 0.175 mmol, 0.5M in toluene). Cool to 0° C. and add 1,2-dihydronaphthalene (5.234 g, 40.205 mmol) via a syringe pump over a 10 h period. After 16 h more, add Na 2 S 2 O 5 (13 g), stir for 10 min at room temperature, then add 80 mL of CH 2 Cl 2 and filter. Wash the solids with 3×50 mL CH 2 Cl 2 , dry the combined filtrates over anhydrous MgSO 4 and concentrate in vacuo to a residue. Flash chromatograph the residue (silica gel, 10% to 100% EtOAc/hexanes) and then recrystallize (EtOAc/hexanes) to yield the chiral diol product. 1 H NMR (CDCl 3 ) δ7.40 (m, 1H); 7.23 (m, 2H); 7.12 (m, 1H); 4.72 (d, 1H, J=2 Hz); 3.94 (m, 1H); 3.92 (m, 1H); 3.78 (m, 3H); 1.95 (m, 2H). Chiral 1 H NMR using a Eu(hfc) 3 shift reagent indicated an enantiomeric excess of 24%.
Step (b): ##STR39##
Combine the product of Step (a) (1.678 g, 10.224 mmol) and 50 mL of CH 3 CN. Add a slurry of (C 6 H 5 ) 3 PBr 2 (4.371 g, 10.354 mmol) in 10 mL CH 3 CN and stir for 30 min. Add a solution of Et 3 N (2.335 g, 23.073 mmol) in 10 mL CH 3 CN and stir for 20 h. Add the reaction mixture to a mixture of 25 mL saturated NaHCO 3 , 10 mL H 2 O and 50 mL TBME. Separate, extract the aqueous layer with 1×25 mL TBME, wash the combined organic layers with 1×25 mL brine, dry over anhydrous MgSO 4 and concentrate in vacuo to a residue. Add 75 mL hexanes to the residue, decant from the resulting precipitate, concentrate the hexanes layer and flash chromatograph (silica gel, 5% to 50% EtOAc/hexanes) to afford the title epoxide. 1 H NMR was identical to the racemic material prepared in Example 2, Step (a).
PREPARATION 3 ##STR40##
Combine 1,2-dihydronaphthalene (1.000 g, 7.690 mmol), 4-phenylpyridine N-oxide (0.263 g, 1.538 mmol), the (S,S)-isomer of the Mn(III) salen catalyst (0.196 g, 0.310 mmol) and 8 mL of CH 2 Cl 2 , and cool to 0° C. Add a cooled solution (0° C.) of NaOCl* (27 mL, 1.105 g, 14.850 mmol, ≈4% NaOCl in water) and stir for 45 min at 0° C. Then extract with 100 mL of hexanes, wash the organic layer with 2×100 mL water and 1×75 mL brine. Extract the combined aqueous washes with 2×30 mL hexanes, and dry the combined organic layers over anhydrous MgSO 4 . Concentrate in vacuo to a residue, then flash chromatograph (as described in Preparation 2) to afford the chiral epoxide. 1 H NMR was identical to the racemic material prepared in step C. Chiral HPLC (Daicel OB® column) indicated the product to have an e.e. of 91%.
EXAMPLE 1 ##STR41##
Combine the aziridinium tetrafluoroborate salt of Example 4 (13.70 g, 40.90 mmol) and 70 mL dry THF to form a suspension. Cool to -20° to -30° C. and add the Grignard reagent of Preparation 1 (335 mL, 53.20 mmol, 0.159M in THF) over a 30 min. period. Stir the reaction mixture at -20° C. for 5 h, warm to room temperature, and stir for 15 h more. Cool to 0° to 10° C. and add 8.6% aqueous NaHCO 3 to adjust the mixture to pH 11. Extract with 3×100 mL EtOAc, wash the combined organic layers with 1×100 mL water and concentrate to a residue. Purify by flash chromatography (silica gel, 2.5-10% MeO/CH 2 Cl 2 ) to give the (+)-enantiomer of the title compound. 1 H NMR (CDCl 3 ) δ: 6.65-7.30 (m, 7H); 4.12 (t, 1 H, J=5.6 Hz); 4.09 (d, 1 H, J=11.3 Hz); 3.82 (s, 3H); 3.21 (s, 3H); 3.12 (s, 3H); 2.95 (m, 3H); 2.60 (dd, 2H, J=5.6, 11.3 Hz); 2.31 (s, 3H); 2.08 (m, 1 H); 1.70-1.80 (m, 1 H).
Step (b): ##STR42##
Combine methanesulfonic acid (7.40 g, 77.003 mmol) and 15 mL CH 2 Cl 2 and cool to 0° to 5° C. Dissolve the product of Step (a) (2.34 g, 6.001 mmol) in 15 mL CH 2 Cl 2 and add the resulting solution to the acid solution over a 5 min period. Heat the mixture at 40° C. for 2 h, then concentrate (50° C./20 Torr) to a residue. Dissolve the residue in 10 mL CH 2 Cl 2 , cool to 10° to 15° C., and add a solution of NaBH 4 (0.280 g, 7.402 mmol) in 15 mL i-PrOH over a 10 min period. Stir for 2 h, then add a solution of Na 2 CO 3 (6.70 g, 63.208 mmol) in 34 mL water to adjust to pH 7. Extract the aqueous layer with 2×10 mL CH 2 Cl 2 , wash the combined organic layers with 2×10 mL water, then dry over anhydrous MgSO 4 and concentrate in vacuo to yield the (-)-enantiomer of the title compound. Purify by flash chromatography (silica gel, 2.5-10% MeOH/CH 2 Cl 2 ). 1 H NMR (CDCl 3 ) δ6.95-7.19 (m, 5H); 5.88 (s, 1 H); 4.78 (d, 1 H, J=7.5 Hz); 3.5-3.62 (m, 1 H); 3.49 (s, 3H); 3.2 (dd, 1 H, J=3.75, 11.3 Hz); 2.65-2.86 (m, 4H); 2.51 (s, 3H); 2.41 (dd, 1 H, J=5.6, 11.3 Hz); 1.98-2.18 (m, 1 H); 1.6-1.8 (dq, 1 H, J=5.6, 11.3 Hz).
EXAMPLE 1A ##STR43##
Combine sulfuric acid (11.4 g, 116 mmol) and 200 mL of CH 2 Cl 2 and cool the mixture to 0° C. Dissolve the product of Example 1, Step (a), (9.08 g, 23.3 mmol) in 200 mL of CH 2 Cl 2 and add the resulting solution to the acid mixture. Warm to room temperature, stir for 24 h., then cool to 0° C. and add BH 3 .tBuNH 2 (2.43 g, 27.9 mmol) in portions. Warm to room temperature and stir for 4.5 h, then cool to 0° C. and extract with 150 mL of 1.5M Na 2 CO 3 (aqueous). Wash the organic layer with brine, dry over Na 2 SO 4 , then concentrate in vacuo to give the (-)-enantiomer of the title compound. 1 H NMR matches material prepared in Example 1.
EXAMPLE 2 ##STR44## Step (a): ##STR45##
Combine 1,2-dihydronaphthalene (24.20 g, 0.186 mol), 70 mL MeOH and 60 mL CH 3 CN. Add KHCO 3 (2.00 g, 0.020 mol), stir 5 min and then add 30% H 2 O (45.00 g, 0.400 mol, 30% solution in H 2 O) at a rate such that the reaction temperature is maintained at 25° to 30° C. Stir for 17 h at room temperature, then quench the reaction with 40% NaHSO 3 (50 g). Concentrate (40°-45° C./60 Torr) the resulting mixture to a residue, partition the residue in 50 mL CH 2 Cl 2 and 150 mL H 2 O and wash the organic layer with 2×50 mL H 2 O. Dry over anhydrous Na 2 SO 4 and concentrate in vacuo to a residue. Distill the residue (70° to 76° C./0.05 Torr) to afford the epoxide product (racemic). 1 H NMR (CDCl 3 ) δ: 7.42 (dd, 1 H, J=1.5 Hz); 7.24 (m, 2H), 7.10 (d, 1 H, J=5 Hz); 3.85 (d, 1 H, J=3 Hz); 3.72 (m, 1 H); 2.80 (m, 1 H); 2.56 (dd, 1 H, J=6, 11 Hz); 2.42 (m, 1 H); 1.86 (m, 1 H).
Step (b): ##STR46##
Charge a 120 mL Teflon® acid digestion bomb with the product of Step (a) (20.09 g, 0.1374 mol) and a stirring bar. Add liquid MeNH 2 (≈25 mL), seal the bomb and stir while heating at 100° C. for 22 h. Cool the bomb and then allow excess MeNH 2 to boil off. Distill the residue (kugelrohr at 160°-175° C./1 Torr) to afford the trans-amino alcohol product (racemic). 1 H NMR (CDCl 3 ) δ: 7.30 (m, 4H); 3.86 (m, 1 H); 3.64 (d, 1H, J=8 Hz); 2.89 (dd, 2H, J=5.4, 7.9 Hz); 2.42 (s, 3H); 2.25 (m, 3H); 1.86 (m, 1 H).
Alternatively, the product of Step (a) is converted to the trans-amino alcohol product by treating with CH 3 NH 2 via the procedure described in Crabb, et al., Mag. Res. in Chem., 24, 798 (1986).
Step (c): ##STR47##
Combine the product of Step (b) (85.8 g, 0.484 mol), 484 mL anhydrous CH 3 CN, K 2 CO 3 (133.8 g, 0.968 mol) and bromoacetaldehyde dimethylacetal (123 g, 0.726 mol), and heat the mixture at reflux for 6 days. Cool to room temperature, decant the mixture and concentrate in vacuo to give a residue. Dissolve the residue in 350 mL of EtOAc and wash with 750 mL of water, then with 2×160 mL of 2.5% HCl (aqueous). Combine the acidic washes, adjust to pH 8.8 by adding saturated Na 2 CO 3 (aqueous) and extract with EtOAc. Wash the organic extract with brine, dry over MgSO 4 and concentrate in vacuo to give the product. 1 H NMR (CDCl 3 ) δ: 7.65 (d, 1 H, J=7.5 Hz); 7.05-7.30 (m, 3H); 4.65 (d, 1 H, J=11.3 Hz); 4.55 (br m, 1 H); 4.10 (br s, 1 H); 3.45 (s, 3H); 3.10 (s, 3H); 2.53-3.00 (m, 5H); 2.47 (s, 3H); 2.05 (m, 1 H); 1.61 (m, 1 H).
Step (d): ##STR48##
Combine the product of Step (c) (81.0 g, 0.305 mol), 1,10-phenanthroline (0.040 g, 0.222 mmol) and 305 mL anhydrous THF, cool the mixture to about 0° C., and add n-butyllithium (191 mL, 0.306 mmol, 1.6M solution in hexanes). Stir for 20 minutes, then add a solution of tosyl chloride (63.7 g, 0.334 mmol) in 200 mL of anhydrous THF. Stir the mixture for 1 h to form the aziridinium salt intermediate. Cool the mixture to about -30° C., then add the Grignard reagent from Preparation 1 (654 mL, 0.641 mmol, 0.98M in THF) and stir for 24 h at room temperature. Add 250 mL saturated NH 4 Cl (aqueous), filter, then concentrate the filtrate in vacuo to a residue. Dissolve the residue in 230 mL of TBME, wash with 100 mL of water, then with 5% HCl (aqueous) (1×200 mL and 3×100 mL). Combine the acidic washes and extract with 230 mL of TBME. Adjust the acidic washes to pH 4.9 by adding saturated Na 2 CO 3 (aqueous) and extract with 300 mL of TBME. Wash the organic layer with brine, dry over Na 2 SO 4 and concentrate in vacuo to yield the title compound (racemic). 1 H NMR spectra is identical to material prepared in Example 1.
EXAMPLE 3 ##STR49##
Combine (+)-α-aminobenzenebutanoic acid (100.14 g, 0.559 mol), NaOH (1.12 L, 1.12 mol, 1N aqueous solution) and Na 2 CO 3 (88.61 g, 0.836 mol), and cool the mixture to about 0° C. Add methyl chloroformate (90 mL, 1.17 mol) dropwise over 15 min and stir at room temperature for 3 h. Add 500 mL 5% HCl then enough 50% HCl to bring to pH 2 (about 400 mL). Add 1 L of CH 2 Cl 2 , separate the layers, wash the aqueous layer with 3×150 mL CH 2 Cl 2 , then wash the combined organic layers with 1×250 mL brine. Dry over anhydrous MgSO 4 and concentrate in vacuo to yield the S-enantiomer of the carbamate product. 1 H NMR (CDCl 3 ) δ: 7.10-7.30 (m, 5H); 5.25 (br d, 1 H); 4.42 (br s, .sup. 1 H); 3.70 (s, 3H); 2.70 (m, 2H); 2.20 (m, 1 H) 2.01 (m, 1 H).
Step (b): ##STR50##
Combine the carbamate of Step (a) (124.9 g, 0.526 mol), 1 L of CH 2 Cl 2 and SOCl 2 (39.0 mL, 0.535 mol) and heat the mixture to reflux for 3 h, then cool to room temperature to form a solution of the S-enantiomer of the acid chloride intermediate. Add the acid chloride solution dropwise to a mixture of AlCl 3 (211.22 g, 1.584 mol) and 750 mL CH 2 Cl 2 over 2 h period, then stir for 1 h more. Add the reaction mixture gradually to 1 L of a saturated NH 4 Cl/ice mixture. Filter the mixture and slurry the solids obtained in 1.5 L CH 2 Cl 2 and 1 L water overnight, filter, combine the filtrates and separate the layers. Wash the aqueous layer with 2×200 mL of CH 2 Cl 2 , then wash the combined organic layers with 1×250 mL of brine. Dry over anhydrous MgSO 4 and concentrate in vacuo to yield the S-enantiomer of the ketone product, mp 119°-121.5° C. 1 H NMR (CDCl 3 ) δ: 8.01 (d, 1H, J=7.5Hz); 7.62 (t, 1H, J=7.5Hz); 7.22-7.35 (m, 2H); 5.90 (br s, 1 H); 4.40-4.50 (m, 1 H); 3.72 (s, 3H); 3.25 (dt, 1 H, J=3.7, 11.2Hz); 3.02 (m, 1 H, J=15Hz); 2.78 (br m, 1 H); 1.95 (dd, 1 H, J=3.7, 15 Hz).
Step (c): ##STR51##
Combine the ketone of Step (b) (4.999 g, 22.802 mmol) and 50 mL anhydrous THF and cool to about 0° C. Add a solution of LiAlH 4 in Et 2 O (46.0 mL, 46.0 mmol, 1M in Et 2 O) gradually over 50 min, then heat at reflux for 2 h. Cool to about 0° C., then add 50 mL 5% HCl and 100 mL Et 2 O and warm the mixture to room temperature. Filter, then wash solids with 25 mL water/10 mL 5% HCl, separate the layers and wash the organic layer with 1×20 mL 5% HCl. Combine the aqueous layers and add 15 mL saturated NaHCO 3 , then add 100 mL EtOAc and separate the layers. Wash the aqueous layer with 3×50 mL EtOAc, dry the combined organic layers over anhydrous MgSO 4 and concentrate in vacuo to yield the trans-1S,2S-isomer of the amino alcohol product. 1 H NMR (CDCl 3 ) δ7.68 (d, 1H, J=7.5Hz); 7.10-7.30 (m, 3H); 4.50 (d, 1 H, J=7.5Hz); 2.90 (m, 2H); 2.67 (m, 1 H); 2.55 (s, 3H); 2.27 (m, 1 H); 2.00 (br s, 2H); 1.60 (m, 1 H). ##STR52## was also obtained. 1 H NMR (CDCl 3 ) δ: 7.48 (m, 1 H); 7.10-7.30 (m, 3H); 4.71 (d, 1 H, J=3.8Hz); 2.75-3.00 (m, 3H); 2.55 (br s, 5H); 1.95 (m, 1 H); 1.75 (m, 1 H).
Step (d): ##STR53##
Combine the trans-amino alcohol of Step (c) (1.010 g, 5.698 mmol), 10 mL anhydrous CH 3 CN and KF over alumina (3.050 g, 19.06 mmol) and stir for 5 min. Add bromo acetaldehyde dimethylacetal (1.4 mL, 11.8 mmol) and heat the mixture at reflux for 2 days. Cool to room temperature, add 25 mL EtOAc and filter though Celite®. Wash the solids with 10 mL EtOAc and 10 mL CH 2 Cl 2 , filter, then concentrate the combined filtrates in vacuo to yield the 1S,2S-isomer of the product. Purify by flash chromatography (silica gel, 30-100% EtOAc/hexanes and then to 60% MeOH saturated with ammonia/EtOAc). 1 H NMR (CDCl 3 ) δ: 7.65 (d, 1 H, J=7.5Hz); 7.05-7.30 (m, 3H); 4.65 (d, 1 H, J=11.3Hz); 4.55 (br m, 1 H); 4.10 (br s, 1 H); 3.45 (s, 3H); 3.10 (s, 3H); 2.53-3.00 (m, 5H); 2.47 (s, 3H); 2.05 (m, 1 H); 1.61 (m, 1 H).
Step (e): ##STR54##
Combine the product of Step (d) (633.3 mg, 2.3867 mmol) and 2 mL THF and cool to about 0° C. Add a solution of n-butyllithium (1.20 mL, 2.45 mmol, 2.04M in hexane), stir for 10 min, then add tosyl chloride (456.4 mg, 2.3939 mmol) and stir for 15 min more to form the aziridinium salt intermediate. Add a solution of the Grignard reagent of Preparation 1 (5.8 mL, 4.8 mmol, 0.83M in THF) and stir at room temperature for 17 h. Add 10 mL saturated NH 4 Cl and 25 mL EtOAc, then filter and wash the solids with 10 mL EtOAc. Combine the filtrates, separate the layers, wash the organic layer with 1×10 mL of brine, dry over anhydrous MgSO 4 and concentrate in vacuo to a residue. Flash chromatograph (silica gel, 5% to 100% EtOAc/hexane) to yield the named compound. 1 H NMR (CDCl 3 ) δ: 6.65-7.30 (m, 7H); 4.12 (t, 1 H, J=5.6Hz); 4.09 (d, 1 H, J=11.3Hz); 3.82 (s, 3H); 3.21 (s, 3H); 3.12 (s, 3H); 2.95 (m, 3H); 2.60 (dd, 2H, J=5.6, 11.3Hz); 2.31 (s, 3H); 2.08 (m, 1 H); 1.70-1.80 (m, 1 H).
EXAMPLE 4 ##STR55##
Charge a 30-mL Teflon® acid digestion bomb with the chiral epoxide (see Preparations 2 and 3) (1.00 g, 6.866 mmol) and amino acetaldehyde dimethyl acetal (2.171 g, 20.651 mmol). Seal and heat to 95° C. for 23 h. Cool and flash chromatograph (silica gel, 1% to 10% MeOH/CH 2 Cl 2 ) to yield the amino alcohol product. 1 H NMR (DMSO-d 6 ) δ: 7.38 (d, 1 H, J=8Hz); 7.10 (m, 3H); 4.72 (d, 1 H, J=2Hz); 4.42 (t, 1 H, J=6.8Hz); 3.82 (m, 1 H); 3.52 (d, 1H, J=7Hz); 3.42 (s, 3H); 3.40 (s, 3H); 2.73 (m, 3H); 2.54 (m, 1 H); 2.00 (m, 1 H); 1.78 (br s, 1 H); 1.68 (m, H).
Step (b); ##STR56##
Combine the product of Step (a) (3.647 g, 14.512 mmol), 75 mL of CH 3 CN and (C 6 H 5 ) 3 PBr 2 (9.472 g, 22.439 mmol) and cool to 0° C. Add a solution of Et 3 N (6.50 mL, 46.600 mmol) in 5.5 mL CH 3 CN dropwise over 10 min, stir for 90 min, then filter and concentrate. Slurry the filtrate with 20 mL n-hexane, filter and concentrate in vacuo to a residue. Flash chromatograph the residue (silica gel, 20-60% EtOAc/hexanes) to yield the aziridine product. 1 H NMR (CDCl 3 ) δ: 7.10-7.35 (m, 4H); 4.51 (t, 1 H, J=6.8Hz); 3.40 (2s, 6H); 2.65-2.87 (m, 2H); 2.42-2.55 (m, 3H); 2.21-2.31 (m, 2H); 1.53 (dd, 1 H J=6.8, 11.3Hz).
The aziridine can also be formed by treating the product of Step (a) with mesyl chloride and Et 3 N instead of (C 6 H 5 ) 3 PBr 2 and Et 3 N.
Step (c): ##STR57##
Combine the product of Step (b) (12.60 g, 51.30 mmol) and 200 mL dry CH 2 Cl 2 , and cool to -20° C. Add purified (CH 3 ) 3 OBF 4 (12.00 g, 81.00 mmol) and stir for 20 h at -20° C. Filter off the excess (CH 3 ) 3 OBF 4 , while excluding moisture, then treat the filtrate with Et 2 O at -20° C. Collect the resulting precipitate under argon, wash with cold Et 2 O and dry under vacuum at room temperature to give the chiral aziridinium tetrafluoroborate salt. 1 H NMR (CDCl 3 ) δ: 7.60 (dd, 1 H); 7.30 (m, 3H); 4.80 (t, 1 H); 4.45 (d, 1 H); 4.00 (m, 1H); 3.80 (dd, 1H); 3.50 (d, 6H); 3.35 (dd, 1 H); 2.80-3.05 (m, 1 H); 2.55-2.75 (m, 2H); 2.50 (s, 3H); 2.10-2.40 (m, 1 H).
Purified (CH 3 ) 3 OBF 4 is prepared from commercially available (CH 3 ) 3 OBF 4 as follows. Slurry under argon in dry CH 2 Cl 2 (two volumes) at 0° C. and stirred for 30 min. Filter the mixture under argon, wash with dry CH 2 Cl 2 , dry Et 2 O and then dry in vacuo at room temperature for 3 h. The solid is stored at 5° C. in a desiccator over P 4 O 10 under argon.
EXAMPLE 5 ##STR58##
Charge a 30 mL Teflon® acid digestion bomb with the epoxide of Preparation 2 (or Preparation 3) (2.613 g, 17.872 mmol) and N-methylamino acetaldehyde dimethyl acetal (2.747 g, 23.055 mmol). Seal and heat to 95° C. for 20 h. Cool and flash chromatograph (silica gel, 2% to 5% MeOH/CH 2 Cl 2 ) to give the title compound. 1 H NMR (CDCl 3 )δ: =7.12 (m, 4H); 4.50 (t, 1 H, J=7Hz); 4.13 (s, 1 H); 3.72 (m, 2H); 3.40 (s, 6H); 3.08 (d, 2H, J=7Hz); 3.86 (m, 2H); 2.48 (S, 3H); 2.22 (m, 1 H); 80 (m, 1 H).
EXAMPLE 6 ##STR59##
Combine the chiral aziridine of Example 4, Step (b) (0.50 g, 2.144 mmol) and 4 mL anhydrous THF. Add methyl triflate (0.363 g, 2.209 mmol), stir for 20 min, then add the Grignard reagent of Preparation 1 (1.50 mmol) and stir at room temperature for 17 h. Add 50 mL H 2 O and 50 mL EtOAc, separate, extract the aqueous layer with 1×50 mL EtOAc, and wash the combined organic layers with 1×25 mL brine. Dry over anhydrous MgSO 4 and concentrate in vacuo to a residue. Flash chromatograph the residue (silica gel, 20-40% EtOAc/hexanes) to the title compound. 1 H NMR was identical to the material prepared in Example 3.
EXAMPLE 7 ##STR60##
Combine the racemic amino alcohol from Example 2, Step (b) (160 g) and 1 L of MeOH. Add a hot solution of L-(+)-tartaric acid (68 g) in 300 mL of MeOH. Seed the mixture with a few crystals of the L-(+)tartrate salt of 1R,2R-isomer of the title compound and stir while cooling the mixture to -5° C. Filter and wash the solid with cold MeOH to give the tartrate salt.
Dissolve the tartrate salt in hot MeOH and concentrate until crystals begin to form. Stir the resulting mixture while cooling to -5° C. Filter and wash with cold MeOH to obtain the purified tartrate salt. m.p.=214°-216° C. [α] D 20 ° C. =+28.1° (water). Elemental Analysis: calculated for C 26 H 36 N 2 O 8 --C, 61.92;H, 7.15; N, 5.55; found--C, 61.89;H, 7.12; N, 5.59.
Add the purified tartrate salt (61.33 g, 0.122 mol) to 10% NH 40 H (183 mL), then extract with TBME (3×250 mL). Combine the extracts, dry over MgSO 4 and concentrate in vacuo to give the chiral amino alcohol. [α] D 2 ° C. =+15.3° (MeOH). 1 H NMR using a chiral shift reagent of the formula ##STR61## indicates >99% e.e. for the chiral amino alcohol.
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Disclosed are a process and intermediates of the formulae ##STR1## wherein X - is halide, BF 4 - , R 3 SO 3 - , wherein R 3 is C 1 -C 6 alkyl, CF 3 , C 1 -C 6 alkylphenyl or phenyl, and Q is a group of the formula ##STR2## wherein R is C 1 -C 6 alkyl; useful for preparing benzazepine intermediates of the formula ##STR3## These benzazepine intermediates are useful for preparing benzazepines having activity as selective D1 receptor antagonists.
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FIELD OF INVENTION
[0001] The invention generally relates to compositions containing Glycosaminoglycans, partially hydrolysed Glycosaminoglycans or Glycosamines, chemically modified or not, and proteins, partially hydrolysed proteins or peptides, chemically modified or not, such as for example collagens.
STATE OF THE ART
[0002] The formulation of homogenous compositions containing highly hydrophilic Glycosaminoglycans, partially hydrolysed Glycosaminoglycans or Glycosamines, chemically modified or not, and proteins, partially hydrolysed proteins or peptides, chemically modified or not provides viscoelastic solids or semi-solids with limited mechanical properties and limited properties for biological, pharmacological or medicinal usages.
GENERAL DESCRIPTION OF THE INVENTION
[0003] The problems mentioned in the previous chapter may be solved with the composition according to the present invention.
[0004] To this effect, the composition according to the invention comprise a polyhydroxyurethane, a glycosaminoglycan, a partially hydrolysed Glycosaminoglycans or Glycosamines, chemically modified or not, and proteins, partially hydrolysed proteins or peptides, chemically modified or not. The polyhydroxyurethane is obtained by the covalent coupling of cyclic carbonates (CC) and polyamines (PA) chemical functions.
[0005] Preferably the composition is obtained by the polymerisation or covalent bound formation of a preparation containing molecules with cyclic polycarbonates functional groups and Glycosaminoglycans, partially hydrolysed Glycosaminoglycans or Glycosamines, or chemically modified or not with a preparation containing molecules with polyamines functional groups, proteins, partially hydrolysed proteins or peptides, chemically modified or not. The Glycosaminoglycans, partially hydrolysed Glycosaminoglycans or Glycosamines and the proteins, partially hydrolysed or not, or the peptides may be chemically modified with the constituents of the polyhydroxyurethanes.
[0006] The Glycosaminoglycans partially hydrolysed Glycosaminoglycans or Glycosamines chemically modified with monomers or pre-polymers of the polyhydroxyurethanes can be covalently bound to proteins, partially hydrolysed proteins or peptides, chemically modified or not with monomers or pre-polymers of the polyhydroxyurethanes to give new compositions with innovative physical, biological, pharmacological or medicinal properties.
[0007] The composition according to the invention may be used in several applications such as the preparation of micro-gel or micro-particles to deliver active pharmaceutical substances or to support living cells, or for the treatment of surfaces in contact with living materials, or for the treatment of surfaces to provide them specific affinities to polysaccharides, proteins, partially hydrolysed proteins and peptides, or to chemically modify proteins, partially hydrolysed proteins and peptides to provide them novel physical, biological, pharmacological or medicinal properties or the reconstruction and the substitution of extra cellular matrix in vitro or in vivo.
[0008] The extra cellular matrix is the non cellular part presents in all tissues and organs. Its functions are essentially linked to its structure and its physical properties, but also to its biochemical composition and its essential constituents and their biomechanical functions.
[0009] Fundamentally the Extra cellular Matrix (ECM) is constituted of water, proteins and polysaccharides. Every ECM processes a unique biochemical composition having in common the essential presence of proteins exhibiting various conformations such as the fibrillar structure of collagens, and glycosaminoglycans forming hydrated gels. Collagens and the other fibrillar proteins are essentially hydrophobic in the haemostatics' conditions of the ECM, while glycosaminoglycans are strongly hydrophilic. The reconstruction in vitro and in vivo of an ECM, based on those two essential families of substances, with the appropriate mechanical characteristics in biocompatible conditions is one of the applications of this innovative formulation.
[0010] When the ECM is damaged or destroyed due to different affections or traumas, or when it has been deformed, or has partially or totally disappeared due to processes associated with aging, traumas, or erosion, techniques currently exist to reconstruct or replace it.
[0011] Those techniques can be classified in three general families:
The use of implants and biocompatible prostheses with no relation to the original composition of the ECM and without living cells. The use of implants and biocompatible mechanical scaffolds based on compositions with limited relation to the original composition of the ECM, but allowing living cells to proliferate in the mimetic ECM. Autologous grafts based on the extraction of healthy and functional ECM of the patient to reconstruct the damaged parts.
[0015] Those techniques are widely used but they all carry their well knows own drawbacks, such as:
The heavy operation traumas and the difficulties to replace prostheses without living cells. The weak integration and incorporation of functionalised scaffolds with neighbouring ECM. The limitation to find adequate healthy ECM in autologous grafts.
[0019] The present invention allows reconstructing a biocompatible ECM constituted of polyhydroxyurethanes and the essential constituents of the original ECM, the proteins and the glycosaminoglycans. This ECM is formed in vitro or in vivo by the polymerisation of the monomers or pre-polymers functional groups of the polyhydroxyurethanes supporting the solubilisation and the creation of close contacts or covalent bonds between proteins, partially hydrolysed proteins or peptides, chemically modified or not and Glycosaminoglycans, partially hydrolysed Glycosaminoglycans or Glycosamines chemically modified or not in biocompatible conditions.
[0020] In some embodiments the composition according to the invention is obtained via two preparations, named “preparation a” and “preparation b” in the present document.
Preparation a
[0021] The essential constituents for its intended use in the preparation a are the glycosaminoglycans such as, the Chondroitin sulphates; the Hyaluronic acid; the Heparan sulphates; the Dermatan sulphates; the Keratan sulphates; the Aggrecan; their hydrolysed fractions or their glycosamines and polyglycosamines constituents; the above constituents can be chemically modified with one or more of the monomers or pre-polymers unit of the polyhydroxyurethane and the mixtures of those substances, here down named the “GAG blend”.
[0022] The “GAG blend” of the preparation a is dispersed or dissolved in the continuous media containing an acceptable solvent at a concentration above 1% and optionally monomers or pre-polymers of the polyhydroxyurethane not covalently bound to the “GAG blend”, for example a cyclic polycarbonates with cycles of 5 to 8 atoms.
[0023] More particularly cyclic polycarbonates of polyhydroxylated molecules carrying at least three, primary or secondary, non aromatic, hydroxyl functions.
[0024] For example, cyclic polycarbonates of erythritol, xylitol, arabitol, ribitol, sorbitol, dulcitol, mannitol, maltitol, isomaltitol, lactitol, or polyether polyols and the mixtures of the above as well as cyclic carbonates and polycarbonates of (1,2-dihydroxyethyl), or (2,3-dihydroxypropyl) ether, ester, ketone, amide, phosphate, sulphate, sulphide, disulfide, alkanes, cycloalkanes, alkenes, cycloalkenes, aryls and heterocycles containing one or more oxygen atom, or aromatic heterocycles containing one or more nitrogen or sulphur atom.
[0025] The non commercial cyclic polycarbonates of the preparation a are obtained following methods described in the literature and the prior art, for example, the method described by Union Carbide Corporation in the U.S. Pat. No. 3,072,613 dated 8 Jan. 1963.
[0026] For example the non commercial monomer cyclic polycarbonate of Diglycerol is obtained by slow heating up to a temperature of 130° Celsius a mixture containing Diglycerol, an excess of diethyl carbonate and a catalytic quantity of sodium carbonate. The yield is very high.
[0027] The pre-polymers of the polyhydroxyurethanes with a Degree of polymerisation from 3 to 200′000, preferably from 3 to 20′000 are obtained following methods described in the literature and the prior art, for example, the method described by Union Carbide Corporation in the U.S. Pat. No. 3,072,613 dated 8 Jan. 1963. The pre-polymer of the polyhydroxyurethanes of the preparation a are formulated and prepared by ways ensuring that their terminal endings are cyclic carbonate functions.
[0028] The chemically modified glycosaminoglycans with components of the polyhydroxyurethane are obtained following methods described in the literature and the prior art. For example, a modified Hyaluronic acid of the “GAG blend” is obtained by its deacetylation in caustic media, followed by its esterification with the cyclic polycarbonate of Diglycerol, followed by its carbamatation with the same or another cyclic polycarbonate after pH adjustment between 8 and 5. The glycosaminoglycan chemically modified with any one of the polycarbonates described above can be further modified with a diamine or polyamine described in the present invention. The reaction of carbamatation of the side chain of the modified Hyaluronic acid is carried in the presence of an acceptable solvent, such as for example, but not limited to water at a temperature between zero and 150° Celsius, preferably between 15 and 80° Celsius. The resulting chemically modified Hyaluronic acid can be further carbamated with a cyclic polycarbonate in the condition described above. The successive carbamatation of the modified Hyaluronic acid can be further made to construct a Polyhydroxyurethane side chain on the modified Hyaluronic acid of 3 to 25 monomer entities terminated with cyclic carbonates. The same procedure can be applied to partially hydrolysed Glycosaminoglycans or Glycosamines described in the invention.
[0029] Additionally the preparation a can contain proteins, partially hydrolysed proteins or peptides, the “Blend of Proteins”, chemically modified with pre-polymers of polyhydroxyurethanes or polyhydroxyurethanes, terminated with cyclic carbonates functions.
[0030] The chemically modified “Blend of Proteins” is obtained, for example by dissolving collagen in Bis(1,4-aminopropyl) Piperazine, followed by its amidation with a mixture of Carbodiimide (EDC) and N-Hydroxysuccinimide, followed by the precipitation of the modified collagen in TBME (Ter-ButylMethyl Ether), followed by the dissolution and neutralisation of the wet precipitate in a solution of anhydrous Ethanol with 4% of acetic acid, followed by a precipitation of the modified collagen in Ethyl acetate, centrifugation and drying under vacuum. Similarly to the chemical modification of the “GAG Blend” described above, this chemically modified “Blend of Proteins” can, after its amidation, be further carbamated with one of the cyclic polycarbonate described in the present invention in the presence of an acceptable solvent at a temperature between zero and 150° Celsius, preferably between 15 and 80° Celsius. The resulting chemically modified protein can be further carbamated with one of the diamine or polyamine described in the present invention. The successive carbamatation of the “Blend of Proteins” can be further made to construct a Polyhydroxyurethane side chain of 2 to 26 monomers entities terminated by cyclic carbonates functions on the “Blend of Proteins”.
[0031] The preparation a contains the constituents of the invention carrying terminal non reacted cyclic carbonates. The quantity of non reacted cyclic carbonates functions from all constituents of the preparation a is sufficient to polymerise or covalently bind to the non reacted primary or secondary amine functions from all constituents of the preparation b to obtain the desired properties from the composition containing polyhydroxyurethanes and glycosaminoglycans, partially hydrolysed Glycosaminoglycans or Glycosamines, chemically modified or not and proteins, partially hydrolysed proteins or peptides, chemically modified or not.
Preparation b
[0032] The essential constituents for the intended use in the preparation b are the proteins, such as, the collagens, the elastins, the keratins, the fibronectins, the actins, the myosins, the laminins, their hydrolysed fractions or peptides; the above constituents chemically modified with one or more components of the polyhydroxyurethanes and the mixtures of those substances, hereafter named the “Blend of Proteins”.
[0033] The chemically modified, proteins or peptides with components of the polyhydroxyurethane are obtained following methods described in the literature and the prior art. For example, a modified collagen for the “Blend of Proteins” is obtain by dissolving collagen in Bis(1,4-aminopropyl) Piperazine, followed by the amidation with a mixture of Carbodiimide (EDC) and N-Hydroxysuccinimide, followed by the precipitation of the modified collagen in TBME (Ter-ButylMethyl Ether), followed by the dissolution and neutralisation of the wet precipitate in a solution of anhydrous Ethanol with 4% of acetic acid, followed by a precipitation of the modified collagen in Ethyl acetate, centrifugation and drying under vacuum. Similarly to the chemical modification of “The GAG Blend” described in the preparation a, the chemically modified protein or peptide can, after its amidation, be further carbamated with one of the cyclic polycarbonate described in the present invention in the presence of an acceptable solvent at a temperature between zero and 150° Celsius, preferably between 15 and 80° Celsius. The resulting chemically modified protein can be further carbamated with one of the diamine described in the present invention. The successive carbamatation of the “Blend of Proteins” can be further proceed to construct a Polyhydroxyurethane side chain of 1 to 25 monomers entities terminated by primary and secondary amine functions on the “Blend of Proteins”.
[0034] The “Blend of Proteins” is dispersed or dissolved in the continuous media of the preparation b containing an acceptable solvent such as for example, but not limited to water, at a concentration above 1% and optionally monomers or pre-polymers of the polyhydroxyurethane not covalently bound to the “Blend of Proteins”, for example a primary or secondary polyamines.
[0035] The useful primary or secondary polyamines in the present invention are primary or secondary polyamines of ether, ester, ketone, amide, phosphate, sulphate, sulphide, disulfide, alkanes, cycloalkanes, alkenes, cycloalkenes, aryls,
[0000] substituted or not with hydroxyl functions; or primary or secondary polyamines and primary or secondary polyalkylamines of heterocycles containing one or more oxygen, nitrogen or sulphur atom; or polyetheramines simple or mixed of ethylene glycol and propylene glycol; or a mixture of those compounds.
[0036] The pre-polymers of the polyhydroxyurethanes with a Degree of polymerisation from 3 to 200′000, preferably from 3 to 20′000 are obtained following methods described in the literature and the prior art, for example, the method described by Union Carbide Corporation in the U.S. Pat. No. 3,072,613 dated 8 Jan. 1963. The pre-polymer of the polyhydroxyurethanes of the preparation b are formulated and prepared by ways ensuring that their terminal endings are primary or secondary amine functions. Additionally the preparation a can contain Glycosaminoglycans, partially hydrolysed Glycosaminoglycans or Glycosamines, the “GAG Blend”, chemically modified with pre-polymers of polyhydroxyurethanes or polyhydroxyurethanes, terminated with primary or secondary amine functions.
[0037] Additionally the preparation a can contain Glycosaminoglycans, partially hydrolysed Glycosaminoglycans or Glycosamines, the “GAG Blend”, chemically modified with monomers or pre-polymers of polyhydroxyurethanes or polyhydroxyurethanes, terminated with primary or secondary amine functions alternatively obtained by amidation. For example, a modified Chondroitin sulphate of the “GAG blend” is obtained by amidation with a diamine or polyamine, such as, but not limited to 1,3-diamino, 2-propanol catalysed by a carbodiimide (EDC) and N-Hydroxysuccinimide at room temperature. The degree of amidation is controlled by the catalyst amount. A partially or fully amidated Chondroitin sulphate obtained is purified by successive washing, precipitation and re-suspension in polar and less polar solvents. The partially amidated Chondroitin sulphate can be further amidated with pre-polymers of polyhydroxyurethanes or polyhydroxyurethanes, terminated with primary or secondary amine functions. The reaction is carried at temperature between zero and 80° Celsius, preferably, 20 and 60° Celsius with carbodiimide and N-Hydroxysuccinimide catalyst system. The modified glycosaminoglycan is isolated by successive washing, precipitation and re-suspension in polar and less polar solvents.
[0038] The preparation b contains the constituents of the invention carrying terminal non reacted primary or secondary amine functions from the di and polyamines. The quantity of non reacted primary or secondary amine functions from the di and polyamines from all constituents of the preparation b is sufficient to polymerise or covalently bind to the non reacted cyclic carbonate functions from all constituents of the preparation a to obtain the desired functions from the composition containing polyhydroxyurethanes and glycosaminoglycans, partially hydrolysed Glycosaminoglycans or Glycosamines, chemically modified or not and proteins, partially hydrolysed proteins or peptides, chemically modified or not.
[0000] Composition from Preparations a and b
[0039] The blend of the preparations a and b allows the creation of a homogenous composition containing the constituents of the present invention, namely the “GAG blend”, the “Blend of Proteins” in combination with polyhydroxyurethanes or covalently bound with polyhydroxyurethanes.
[0040] The useful proportions of the preparations a and b for the blended composition are linked to the desired final application. The molar ratio of cyclic carbonates to amine functions is set between 0.02 and 50. In the example of the substitution or reconstruction of the ECM, those proportions are calculated such as the number of cyclic carbonate functions coming from the preparation a or b are equal or slightly higher than the number of primary and secondary amine functions coming from the preparation b or a.
[0041] The cyclic carbonate functions from the preparation a or b react with the primary and secondary amine functions from the preparation b or a by polymerisation or covalent bounds to form various Polyhydroxyurethanes. During this mixing of the two preparations, the temperature may increase to temperature between 15 and 150° Celsius depending on the constituents of phase a and b, their concentration and the type of mixing technology chosen from the known technologies. The polymerisation or covalent bounds to form various Polyhydroxyurethanes can additionally be controlled by catalysts such as, but not limited to Zinc, Magnesium, Bismuth, Aluminium salts or covalent compounds or Infra Red photonic sources to control the speed of polymerisation and covalent bounds formation.
[0042] The obtained composition comprising Polyhydroxyurethanes, Glycosaminoglycans and proteins is for example useful for the preparation of micro-gel or micro-particles to deliver active pharmaceutical substances or to support living cells, or for the treatment of surfaces in contact with living materials, or for the treatment of surfaces to provide them specific affinities to polysaccharides, proteins, partially hydrolysed proteins and peptides, or to chemically modify proteins and partially hydrolysed proteins and peptides to provide them novel physical, biological, pharmacological or medicinal properties or for the reconstruction and the substitution of extra cellular matrix in vitro or in vivo.
[0043] The innovative composition obtained by the mixture of the preparations a and b can be complemented by physiological solution, cells and their growth factors regulators, minerals, particularly phosphate salts and any other component normally present in the ECM environment or for the purpose of the application.
[0044] This innovative composition is for example useful for the substitution and the reconstruction of connective, epithelial, nervous, muscular, bones, cartilaginous, or dermal, animal or human extra cellular matrix.
[0045] This innovative composition is also useful to coat the surfaces of foreign materials implanted in living organisms for permanent or transitory periods.
DETAILED DESCRIPTION OF THE INVENTION
[0046] The invention will be better understood in the present chapter, with some examples and the following figures:
[0047] FIG. 1 shows the viscoelastic rheological properties of a composition according to a first example of the invention.
[0048] FIG. 2 shows the viscoelastic rheological properties of a composition according to a second example of the invention.
[0049] FIG. 3 shows the viscoelastic rheological properties of a composition according to a third example of the invention.
Example 1
Preparation a
[0050] In a reactor fitted with a mechanical agitator we add 20 parts of Triglycerol (Polyglycerol-3; Solvay), 50 parts of diethyl carbonate and 0.5 part of sodium carbonate finely grounded.
[0051] The blend under agitation is heated over a period of one hour to 90° Celsius, until the mixture appears homogenous. It is than slowly heated to 130° Celsius in one to two hours and then kept at the temperature for another one to two hours. The ethyl alcohol formed during the reaction is eliminated by distillation. After three hours, the mixture is placed under vacuum of about 15 mbar to remove residues of ethyl alcohol and diethyl carbonate.
[0052] The mixture is hot filtered to remove the catalyst and 1.5 parts of Chondroitin-4-sulphate sodium salt (Sigma-Aldrich) is added.
Preparation b
[0053] We add 1.5 part of chemically hydrolysed collagen type II of porcine origin (Meitek Technology Qingdao Co. Ltd) to 20 parts of 1,3-diamino-2-propanol. The preparation b is kept under agitation at room temperature to obtain a viscous homogenous liquid.
[0000] Composition from the Preparations a and b
[0054] 20 parts of preparation a are preheated at about 50° Celsius. 6.5 parts of preparation b are added and blended with a conventional high shear mixing equipment. The temperature of the composition rises rapidly to 80° Celsius. The composition is cooled down to around 45° Celsius and 4.8 parts of a 5% Hyaluronic acid (Sigma-Aldrich) solution in a PBS buffer is added and mixed with the same equipment as above.
[0055] The composition obtained is useful as a substitute of Extra Cellular Matrix, and shows viscoelastic rheological properties as shown in the FIG. 1 .
Example 2
Preparation a
[0056] In a reactor fitted with a mechanical agitator we add 20 parts of Triglycerol (Polyglycerol-3; Solvay), 12 parts of Sorbitol (Sigma-Aldrich), 100 parts of diethyl carbonate and 1 part of sodium carbonate finely grounded.
[0057] The blend under agitation is heated over a period of one hour to 115° Celsius, until the mixture appears homogeneous. It is than slowly heated to 130° Celsius in about one hour and then kept at the temperature for another one to two hours. The ethyl alcohol formed during the reaction is eliminated by distillation. After three hours, the mixture is placed under vacuum of about 15 mbar to remove residues of ethyl alcohol and diethyl carbonate.
[0058] The mixture is hot filtered to remove the catalyst and 3.2 parts of Chondroitin-4-sulphate sodium salt (Sigma-Aldrich) are added.
Preparation b
[0059] We dissolve 0.7 part of insoluble Type I collagen from beef Achilles tendon (Sigma-Aldrich) in 7 parts of 1,3-diamino-2-propanol, 4.9 parts of 3,6-dioxaoctamethylendiamine (JEFFAMIN EDR 148, Huntsman), and 2.1 parts of Hexamethylenediamine. We add 2.1 parts of chemically hydrolysed collagen type II of porcine origin (Meitek Technology Qingdao Co. Ltd) at the mixture preheated at about 40° Celsius to obtain the preparation b.
[0000] Composition from the Preparations a and b
[0060] 20 parts of preparation a are preheated at about 50° Celsius. 15.8 parts of preparation b are added and blended with a conventional high shear mixing equipment. The temperature of the composition rises rapidly above 80° Celsius. The obtained composition is useful for example to coat surfaces of foreign materials implanted in living organisms for permanent or transitory periods. The composition 2 shows viscoelastic rheological properties as shown in the FIG. 2 .
Example 3
Preparation a
[0061] In a reactor fitted with a mechanical agitator we add 23.3 parts of Triglycerol (Polyglycerol-3; Solvay), 6.7 parts of Diglycerol (TCI Europe N.V), 75 parts of diethyl carbonate and 1.5 part of sodium carbonate finely grounded. The blend under agitation is heated over a period of one hour to 90° Celsius, until the mixture appears homogeneous. It is than slowly heated to 130° Celsius in about one hour and then kept at the temperature for another one to two hours. The ethyl alcohol formed during the reaction is eliminated by distillation. After three hours, the mixture is placed under vacuum of about 15 mbar to remove residues of ethyl alcohol and diethyl carbonate. The mixture is hot filtered to remove the catalyst and 2 parts of Chondroitin-4-sulphate sodium salt (Sigma-Aldrich) are added.
Preparation b
[0062] We dissolve 1 part of insoluble Type I collagen from beef Achilles tendon (Sigma-Aldrich) in 10 parts of 1,3-diamino-2-propanol. We add 1 parts of chemically hydrolysed collagen type II of porcine origin (Meitek Technology Qingdao Co. Ltd) at the mixture preheated at about 50° Celsius to obtain the preparation b.
[0000] Composition from the Preparations a and b
[0063] 15 parts of preparation a are preheated at about 50° Celsius. 7.25 parts of preparation b are added and blended with a conventional high shear mixing equipment. The temperature of the composition rises rapidly above 80° Celsius. The obtained composition is useful for example as substitute of the extra cellular matrix, or to coat surfaces of foreign materials implanted in living organisms for permanent or transitory periods. The composition 3 shows viscoelastic rheological properties as shown in the FIG. 3 .
Example 4
Preparation a
[0064] In water with 0.25 M NaOH we introduce 5% by weight of Hyaluronic Acid (Sigma-Aldrich), the product is deacetylated at Room temperature for 12 H. We add Diglycerol Dicarbonate prepared as described above in 50% acetone solution to the mixture. The quantity added is calculated as the amount of free carboxylic acid of the Hyaluronic acid. After 1 to 12 hours at a temperature between 20° and 75° Celsius, the reaction media is neutralised with 1 M aqueous HCl leading to the exhaust of CO 2 . We add to the composition the same amount of Diglycerol Dicarbonate in 50% acetone as previously at a temperature between 20° and 75° Celsius. The mixture is stirred for 10 minutes to 10 hours and concentrated under vacuum to provide a chemically modified glycosaminoglycan.
Preparation b
[0065] In Ethyl Acetate we add 5% by weight of 1,4-Bis(3-aminopropyl)piperazine and 6% by weight of cyclic diglycerol dicarbonate. The reaction media is heated between 50 and the boiling point for 2 to 15 hours to produce the corresponding polyhydroxyurethane terminated by amine functions. The Ethyl Acetate is removed by vacuum distillation and the polyhydroxyurethane re-dissolved in an acceptable solvent such as for example, but not limited to water. We add 1% of chemically hydrolysed collagen type II of porcine origin (Meitek Technology Qingdao Co. Ltd) to the pre-polymer of polyhydroxyurethane.
Blend of a and b
[0066] Preparation a and b are mixed in proportions to ensure that the cyclic carbonate functions are equal to or slightly above the amine functions. The resulting composition is a solid transparent product.
Example 5
Preparation b
[0067] We add to 400 ml of 1,4-Bis(3-aminopropyl) piperazine 10 g of chemically hydrolysed collagen type II of porcine origin (Meitek Technology Qingdao Co. Ltd). The mixture is stirred at room temperature until dissolution. We further add 17.5 g of N-Hydroxysuccinimide and 26.75 g of carbodiimide (EDC) in small portion and stir for 12 hours at room temperature to amidate the protein.
[0068] The amidated protein is precipitated from the reaction mixture with two times its volume of ter-Butyl Methyl Ether (TBME).
[0069] The 90 ml wet precipitate from the TBME phase is neutralised with six time its volume of anhydrous EtOH/Acetic acid 4%. The re-desolved amidated collagen in neutralised organic solution is precipitated with 2.5 times its volume of Ethyl Acetate, centrifuged and dried under vacuum.
[0000] Blend of Preparation a from Example 4 and Preparation b
[0070] Preparation a from example 4 and b are mixed in proportions to ensure that the cyclic carbonate functions are equal to or slightly above the amine functions. The resulting composition is a viscoelastic transparent product.
Example 6
Preparation b
[0071] We take 10 parts of preparation b from Example 5 (the “Blend of Proteins”) which is a modified protein, 5 parts of preparation b from example 4 which is a polyhydroxyurethane pre-polymer terminated with amine functions and collagen with and 35 parts of preparation b from Example 3. This pre-blend is the composition containing the amine functions.
Preparation a
[0072] To 20 parts of the preparation a from Example 4 (The “GAG Blend”) which is a modified Glycosaminoglycan, we add and dissolve at a temperature between 45 and 65° Celsius 15 parts of bis-(cyclic carbonate) of Triglycerol prepared as described in example 1. This provide a composition with the cyclic carbonate functions.
Blend of a and b
[0073] Those two pre-blends are mixed to give a composition containing polyhydroxyurethane, modified Glycosaminoglycans, proteins and modified proteins, resulting in an elastic semi-solid white foam.
Example 7
Preparation a
[0074] Preparation a from example 4
Preparation b
[0075] We dissolve 0.7 part of insoluble Type I collagen from beef Achilles tendon (Sigma-Aldrich) in 7 parts of 1,3-diamino-2-propanol, 4.9 parts of 3,6-dioxaoctamethylendiamine (JEFFAMIN EDR 148, Huntsman), and 2.1 parts of Hexamethylenediamine. We add 2.1 parts of chemically hydrolysed collagen type II of porcine origin (Meitek Technology Qingdao Co. Ltd) to the mixture preheated at about 40° Celsius to obtain the preparation b.
[0076] We add to 10 parts of this preparation b of collagen in monomer of polyhydroxyurethanes, 5 parts of pre-polymer of polyhydroxyurethanes terminated with amine functions as prepared in the preparation b of the example 4.
Blend of a and b
[0077] To those 15 parts of preparation b which contain the amine functions we add and mix 20 parts of preparation a from example 4 to give a transparent hydrogel at 37° Celsius with polyhydroxyurethanes, chemically modified glycosaminoglycans and proteins.
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A composition comprising Polyhydroxyurethanes, Glycosaminoglycans, hydrolysed glycosaminoglycans, glycosamines of glycosaminoglycans, chemically modified or not and a Protein or a peptide; said protein being collagen, elastin, keratin, fibronectin, actin, myosin, laminin, a peptide or a blend of those proteins or peptides, fibrillated, hydrolysed, chemically modified or not. This homogenous composition is obtained by the polymerisation or the covalent bounding of two preparations containing cyclic polycarbonates, polyamines, glycosaminoglycans, hydrolysed glycosaminoglycans, glycosamines, chemically modified or not and proteins or peptides or a blend of those proteins or peptides, fibrillated, hydrolysed, chemically modified or not.
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CROSS REFERENCE OF RELATED APPLICATION
[0001] This is a U.S. National Stage under 35 U.S.C 371 of the International Application PCT/CN2015/089217, filed Sep. 9, 2015, which claims priority under 35 U.S.C. 119(a-d) to CN 201410479580.7, filed Oct. 18, 2014; CN 201510535230.2, filed Aug. 27, 2015; and CN 201510536104.9, filed Aug. 27, 2015.
BACKGROUND OF THE PRESENT INVENTION
Field of Invention
[0002] The present invention belongs to the technical field of machine vision inspection, relating to a defects evaluation system and method for spherical optical components.
Description of Related Arts
[0003] Spherical optical components are widely used in many optical systems including the large-aperture space telescope, the Inertial Confinement Fusion (ICF) system and the high-power laser system. However, defects such as scratches and digs on the surface of components can not only affect the imaging quality of optical systems, but also generate unnecessary scattering and diffraction light resulting in energy loss in the high-power laser system, which may also lead to a secondary damage because of the high energy. Therefore, it is highly necessary to inspect the surface defects of the spherical optical components before put into use and to digitally evaluate defects information to provide reliable numerical basis for the use of spherical optical components.
[0004] The traditional methods for inspecting the defects of spherical optical components are mostly based on the visual inspection. Using a strong light to illuminate the spherical surface, the inspector observes in different directions by naked eyes with the reflection method and the transmission method. However, the visual inspection suffers from subjectivity and uncertainty. It is greatly influenced by the proficiency of the inspector and can't provide quantitative description of defects information. Furthermore, a long-time inspection can cause eyes fatigue resulting in lower reliability. Accordingly, there remains a need for a system that can achieve the automatic evaluation for the surface defects on spherical optical components based on machine vision instead of manual visual method to considerably enhance the efficiency and precision of inspection.
SUMMARY OF THE PRESENT INVENTION
[0005] In allusion to the deficiencies of the existing technology, the present invention aims to provide an evaluation system and method to achieve the automatic inspection of the surface defects on spherical optical components.
[0006] Based on the principle of the microscopic scattering dark-field imaging, the present invention implements a sub-aperture scanning for the surface of spherical optical components and then obtains surface defects information with image processing. Firstly, the present invention takes full advantage of the characteristic that the surface defects of spherical optical components can generate scattering light when an annular illumination beam irradiates on the surface, to implement the sub-aperture scanning and imaging that covers the entire spherical surface. Then, a series of procedures such as the global correction of sub-apertures, the 3D stitching, the 2D projection and the digital feature extraction are taken to inspect spherical surface defects. Finally, actual size and position information of defects are evaluated quantitatively with the defects calibration data.
[0007] Spherical surface defects evaluation system (SSDES) comprises a defect imaging subsystem and a control subsystem. The defect imaging subsystem is adapted to acquire microscopic scattering dark-field images suitable for digital image processing. The control subsystem is adapted to drive the movements of various parts of the defect imaging subsystem, to realize automatic scanning and inspection of defects on the spherical surface. The defect imaging subsystem comprises an illumination unit, a microscopic scattering dark-field imaging (MS-DFI) unit, a spatial position and posture adjustment (SPPA) unit and a centering unit. The illumination unit is adapted to provide dark-field illumination for microscopic scattering dark-field imaging of spherical surface. The MS-DFI unit is adapted to collect scatter light induced by the surface and image. The SPPA unit is adapted to achieve five-dimensional spatial position and attitude adjustment including three-dimensional translation, rotation and swing, easy to acquire sharp images at various locations on the surface of the spherical optical component. The centering unit is adapted to analyze the position of the curvature center of the component. The movement and the adjustment of the illumination unit, the MS-DFI unit, the SPPA unit and the centering unit are driven by the control subsystem.
[0008] The illumination unit comprises illuminants and an illuminant support bracket. The illuminant comprises a uniform surface light source and a lens group with front fixed lens group, zoom lens group and rear fixed lens group installed in. The optical axis of the lens group intersects with the optical axis of the MS-DFI unit at the incident angle of γ ranging from 25 to 45 degrees.
[0009] The illuminant support bracket comprises a top fixation board, a hollow shaft, a worm gear, a worm, a servo motor, a motor support, bearings, a rotating cylindrical part and illuminant fixation supports. The illuminant is fixed on the illuminant support bracket which is fixed on the rotating cylindrical part. The rotating cylindrical part has flexible connections with the hollow shaft by the bearings. The worm gear, installed on the rotating cylindrical part has flexible connections with the worm and achieve circular rotation by the drive of the servo motor. The servo motor is fixed on the top fixation board by the motor support and the hollow shaft is also fixed on the top fixation board, which is fixed on the Z-axis translation stage. The illuminant support bracket is applied to provide illumination for spherical surface defects in all directions.
[0010] Three illuminants are in annular and uniform distribution at the angle interval of 120° by the illuminant fixation support on the rotating cylindrical part.
[0011] The light path of the illumination unit is formed as follows. The zoom lens group is moved to the position in the lens group calculated according to the curvature radius of the spherical optical component. The parallel light emitted by the uniform surface light source enters into the lens group and passes through the front fixed lens group, the zoom lens group and the rear zoom lens group in turn. Finally it becomes convergent spherical wave with the aperture angle of θ l .
[0012] Taking advantages of the induced scatter light by the principle that defects on the smooth surface modulate the incident light, the MS-DFI unit achieves microscopic dark-field imaging of defects and acquires dark-field images of defects. The principle is as follows. The incident light is incident onto the surface of thespherical optical component. If the spherical surface is smooth, the incident light, according to the law of reflection in geometrical optics, is reflected on the surface to form the reflected light, which can't enter the MS-DFI unit. If there is defect on the surface of the spherical optical component, the incident light is scattered to form the scatter light, which is received by the MS-DFI unit and forms the dark-field image of defects.
[0013] The SPPA unit comprises an X-axis translation stage, a Y-axis translation stage, a Z-axis translation stage, a rotation stage, a swing stage and a self-centering clamp. The swing stage comprises an inner plate and a shell plate. The self-centering clamp has fixed connections with the rotation axis of the rotation stage and the base of the rotation stage is fixed on the inner plate of the swing stage. The inner plate has flexible connections with the shell plate so that the inner plate is capable of swinging by the shell plate. The sections of the inner plate and the shell plate are both in U-shape. The undersurface of the shell plate of the swing stage is fixed on the working surface of the Y-axis translation stage and the Y-axis translation stage is fixed on the working surface of the X-axis translation stage. The X-axis translation stage and the Z-axis translation stage are fixed on the same platform.
[0014] The centering unit comprises a light source, a focusing lens group, a reticle, a collimation lens, a beam splitter, an objective, a plane reflector, an imaging lens and a CCD. The light beam emitted by the light source passes through the focusing lens group and irradiates the reticle with a crosshair on. Then, the light beam passes through the collimation lens, the beam splitter and the objective and irradiates on the spherical optical component. The light beam is reflected on the surface and the image of the crosshair on the reticle is indicated by the reticle image. The reflected light beam passes through the objective again and deflects at the beam splitter. Subsequently, the reflected light beam is reflected by the plane reflector and passes through the imaging lens. Finally, the light beam focuses on the CCD and the CCD acquires the image of the crosshair on the reticle.
[0015] The control subsystem comprises a centering control module, an illumination control module, a five-stage translation control module and an image acquisition control module. The centering control module comprises a centering image acquisition unit and a four-stage translation control unit. The centering image acquisition unit is applied to control the CCD of the centering unit to acquire the image of the crosshair and the four-stage translation control unit is applied to control the movement of the X-axis translation stage, the Y-axis translation stage and the Z-axis translation stage and the rotation of the rotation stage during the process of centering. The illumination control module comprises an illumination rotating control unit and an illuminant zoom control unit. The illumination rotating control unit is applied to control the rotation of the illuminant support bracket of the illumination unit and the illuminant zoom control unit is applied to control the movement of the zoom lens group to change the aperture angle θ l of the emitted convergent spherical wave. The five-stage translation control module is applied to control the movement of the X-axis translation stage, the Y-axis translation stage and the Z-axis translation stage, the rotation of the rotation stage and the swing of the swing stage during the process of inspection. The image acquisition control module comprises a sub-aperture image acquisition unit and a microscope zoom control unit. The sub-aperture image acquisition unit is applied to control the MS-DFI unit to acquire sub-aperture images and the microscope zoom control unit is applied to change the image magnification of the MS-DFI unit.
[0016] The evaluation method comprises an automatic centering module, a scan-path planning module, an image processing module and a defect calibration module. The automatic centering module is adapted to automatic centering of the spherical surface, achieving accurate measurement of the curvature radius and axial consistency alignment between the rotation axis and the optical axis of the spherical optical component. The scan-path planning module is adapted to plan the optimal scan-path for the spherical surface. The image processing module is adapted to achieve spherical surface defects inspection with high precision. The defect calibration module is adapted to establish the relationship between pixels and actual size in sub-aperture images at any locations on the spherical surface in order that the actual size of defects can be obtained. The evaluation method comprises the following steps:
[0017] Step1.The implementation of automatic centering of the spherical optical component by the automatic centering module.
[0018] Step2. The completion of optimal scan-path planning and full-aperture scanning for the spherical optical component by the scan-path planning module.
[0019] Step3. The obtainment of spherical surface defect information by the image processing module and the defect calibration module.
[0020] The implementation of automatic centering of the spherical surface by the automatic centering module according to Step 1 , comprises the following steps:
[0021] 1-1. Initialize the centering unit.
[0022] 1-2. Move the spherical optical component to the initial position where the optical axis of the spherical optical component coincides with the optical axis of the centering unit approximately.
[0023] 1-3. The Z-axis translation stage is controlled to scan along Z-direction to find the sharpest crosshair image by use of image entropy clarity evaluation function.
[0024] 1-4. Judge whether the crosshair image is the surface image or the center image as follows:
[0025] Move the X-axis translation stage and Y-axis translation stage slighted to observe whether the crosshair image in the field of view (FOV) is moved with the movement of translation stages or not. If the crosshair image is moved with the movement of stages, it is the center image of the spherical optical component located at the curvature center of the spherical optical component and then jump to Step 1-5. Otherwise, it is the surface image of the spherical optical component located on the surface of the spherical optical component and then jump to Step 1-9.
[0026] 1-5. Move the crosshair image to the center of FOV by the X-axis translation stage and the Y-axis translation stage. After the movement, the optical axis of the spherical optical component coincides with the optical axis of the centering unit.
[0027] 1-6. Find the position of the rotation axis by rotation measurement in optical alignment as follows:
[0028] The spherical optical component can rotate around the rotation axis of the rotation stage under the self-centering clamp. Every 30° rotation of the rotation stage, CCD acquires a crosshair image. The positions of the crosshair images in the FOV of CCD vary with different rotation angles. The trajectory formed by the center of the crosshair is close to a circle, the center of which is the position of the rotation axis.
[0029] 1-7. Obtain the trajectory center by the least square circle fitting method and the max deviation between the trajectory center and the crosshair center is calculated.
[0030] 1-8. Judge whether the max deviation is lower than the max permissible error. If the max deviation is lower than the max permissible error, the axial consistency alignment is considered completed. Otherwise, the optical axis of the spherical optical component is not coincident with the rotation axis, therefore the center of the crosshair image is moved to the fitting trajectory center by adjusting the self-centering clamp and then jump to Step 1-5.
[0031] 1-9. Move the Z-axis translation stage to image at theoretical curvature center obtained by initialization. The Z-axis translation stage is controlled to scan along Z-direction to find the sharpest crosshair image and then jump to Step 1-5. At the same time, Z-direction displacement from the position of the surface image to the position of the center image is recorded to get the real curvature radius of the spherical optical component, which is the displacement of the Z-axis translation stage.
[0032] The completion of optimal scan-path planning and full-aperture scanning for the spherical optical component by the scan-path planning module according to Step 2, comprises the following steps:
[0033] 2-1. With the fiducial position obtained in the process of axial consistency alignment in Step 1, the spherical optical component is moved by the SSPA unit below the MS-DFI unit. Then the MS-DFI unit acquires the sub-aperture located at the vertex of the spherical surface. For the convenience of the following statement, spherical coordinate system X s Y s Z s is defined here, whose origin O s is located at the curvature center of the spherical optical component and z-axis Z s passes through the vertex of the spherical surface. To achieve the full-aperture sampling, two-dimension movements along the meridian and parallel scanning trajectory is required, combining the swing around X s and the rotation around Z s .
[0034] 2-2. The spherical optical component is driven to swing around X s with swing angle β 1 , one sub-aperture image is acquired on the meridian. After that, rotating around Z s with rotation angle α 1 is implemented to acquire another sub-aperture image on the parallel.
[0035] 2-3. Every time after the rotation around Z s with the same rotation angle α 1 , one sub-aperture is acquired so that multiple sub-apertures on the parallel are obtained.
[0036] 2-4. After the completion of sub-aperture acquisition on the parallel, the spherical optical component is driven to swing around X s again with swing angle β 2 , then one sub-aperture is acquired on meridian.
[0037] 2-5. Every time after the rotation around Z s with the same rotation angle α 2 , one sub-aperture is acquired so that multiple sub-apertures on the parallel are obtained. Full-aperture sampling is finished with several times repetition of such a process that the spherical optical component is driven to swing around X s with swing angle β 2 to acquire multiple sub-apertures on next parallel after the completion of sub-aperture acquisition on this parallel.
[0038] According to Step 2, the completion of optimal scan-path planning and full-aperture scanning for the spherical optical component by the scan-path planning module is characterized by that the sub-aperture plan model is established firstly. In this model, sub-aperture A and sub-aperture B are two adjacent sub-apertures on meridian C. Sub-aperture Aa is adjacent to sub-aperture A on parallel D 1 where sub-aperture A is located. Similarly, sub-aperture Bb is adjacent to sub-aperture B on parallel D 2 where sub-aperture B is located. Besides, the bottom intersection of sub-aperture A and sub-aperture Aa is indicated by P cd , the top intersection of sub-aperture B and sub-aperture Bb is indicated by P cu . So the sufficient conditions for the realization of sub-aperture no-leak inspection is that the arc length is less than or equal to the arc length z, 999 . Under such a constraint, planning result can be solved and obtained by establishing the relationship between swing angle β 1 , swing angle β 2 and rotation angle α 1 , rotation angle α 2 . The solution procedure of swing angle β 1 , swing angle β 2 , rotation angle α 1 and rotation angle α 2 is as follows:
[0039] {circle around (1)} Validate relevant parameters about the spherical optical component, including the curvature radius, aperture of the spherical optical component and the size of the object field of view of the MS-DFI unit.
[0040] {circle around (2)} Specify the initial value of swing angle β 1 and swing angle β 2 according to the above three parameters. After that, calculate the value of rotation angle α 1 and rotation angle α 2 according to the same overlapping area between adjacent sub-apertures on one parallel. Then, figure out arc length and arc length .
[0041] {circle around (3)} Compare arc length and arc length to determine whether the given initial value of swing angle β 2 is appropriate or not. If > , reduce the value of swing angle β 2 by 5% and go back to Step {circle around (2)}. Otherwise, sub-aperture plan for covering the entire spherical surface is finished.
[0042] The obtainment of spherical surface defects information by the image processing module and the defect calibration module according to Step 3, comprises the following steps:
[0043] 3-1. The imaging sub-aperture image is a2D image, which is obtained when the surface of the spherical optical component is imaged by the MS-DFI unit in the image plane. Due to the information loss along the direction of optical axis during the optical imaging process, 3D correction of sub-apertures should be conducted firstly to recover the information loss of surface defects of the spherical optical component along the direction of optical axis during the optical imaging process.3D correction of sub-apertures means that the imaging process of the MS-DFI unit is simplified to be a pin-hole model and imaging sub-aperture images are transformed into 3 D sub-aperture images with geometrical relationship.
[0044] 3-2. For convenience of feature extraction, 3D sub-aperture images obtained after 3D correction of sub-apertures are projected onto a 2D plane with full-aperture projection to obtain the full-aperture projective image.
[0045] 3-3. Feature extraction at low magnification is conducted on the full-aperture projective image; then 3D sizes of defects is obtained with inverse-projection reconstruction; finally, actual sizes and positions of surface defects on the spherical optical component are obtained taking advantages of the defect calibration data got with the calibration module.
[0046] 3-4. Defects are inspected at high magnification to guarantee the micron-scale inspection precision. First, the imaging magnification of the MS-DFI unit is zoomed to high magnification; then, according to the positions obtained by Step 3-3, surface defects are moved to the center of the object field of view to acquire images at high magnification; Finally, feature extraction at high magnification is conducted and micron-scale evaluation results of defects are obtained taking advantages of the defect calibration data got with the calibration module.
[0047] 3-5. Evaluation results are output in the form of 3D panoramic preview of the spherical surface, electronic report and defect location map.
[0048] According to Step 3-1, imaging sub-aperture images are obtained when the surface of the spherical optical component is imaged by the MS-DFI unit in the image plane. The detailed description is as follows:
[0049] 3-1-1. According to the optimal scan-path planned by the scan-path planning module in Step 2, one point p on the surface of the spherical optical component is moved to the point p′ by the SPPA unit.
[0050] 3-1-2. The MS-DFI unit acquires sub-apertures at low magnification. Point p′ is imaged to be image point p″ in the imaging sub-aperture image by the MS-DFI unit.
[0051] 3-1-3. During the process of digital image acquisition, the image-plane coordinate system X c Y c is transformed into the image coordinate system X i Y i and the imaging sub-aperture image is obtained. X-axis X c and y-axis Y c compose the image-plane coordinate system X c Y c , whose origin O c is located at the intersection of the optical axis of the MS-DFI unit and the imaging sub-aperture image. X-axis X i and y-axis Y i compose the image coordinate system X i Y i coordinate system, whose origin O i is located at the top left corner of the digital image.
[0052] According to Step 3-2, the full-aperture projective image is obtained. The detailed description is as follows:
[0053] 3-2-1. 3D sub-aperture images are transformed into spherical sub-aperture images by global coordinate transformation.
[0054] 3-2-2. Spherical sub-aperture images are projected vertically onto the plane to obtain projective sub-aperture images.
[0055] 3-2-3. Projective sub-aperture images are stitched and sizes and positions of defects are extracted in the plane. Precise inspection for surface defects of the spherical optical component can be achieved by inverse-projection reconstruction. The way of direct stitching for parallel circle and annulus stitching for meridian circle is used for image stitching of projective sub-aperture images. The process of image stitching of projective sub-aperture images is as follows:
[0056] {circle around (1)} Projective sub-aperture images are denoised to remove the effect of background noise on stitching accuracy.
[0057] {circle around (2)} After denoising, image registration according to overlapping area is carried out to on adjacent projective sub-aperture images on the same parallel circle.
[0058] {circle around (3)} Adjacent projective sub-aperture images after registration on the same parallel circle are stitched to obtain the annulus image of one parallel circle.
[0059] {circle around (4)} The minimum annulus image containing all overlapping areas is extracted.
[0060] {circle around (5)} The image registration points of the minimum annulus image are extracted to acquire the best registration location, so that the image stitching of projective sub-aperture images is finished.
[0061] According to Step 3-3, feature extraction at low magnification is conducted on the full-aperture projective image; then, 3D sizes of defects is obtained with inverse-projection reconstruction; finally, actual sizes and positions of surface defects of the spherical optical component are obtained taking advantages of the defect calibration data got with the defect calibration module. The detailed description is as follows:
[0062] 3-3-1. Extract features of the 2D full-aperture image after image stitching of projective sub-aperture images to obtain sizes and positions of defects.
[0063] 3-3-2. Obtain 3D sizes and positions in pixels of surface defects of the spherical optical component by inverse-projection reconstruction.
[0064] 3-3-3. Taking advantages of the defect calibration data got with the defect calibration module, convert 3D sizes and positions in pixels to actual sizes and positions.
[0065] The defect calibration data according to Step 3-3 and Step 3-4 comprises defect length calibration data and defect width calibration data. The process of defect length calibration is to establish the relationship between actual lengths of line segments at any locations on the spherical surface and corresponding pixels in spherical sub-aperture images. The defect length calibration data is obtained as follows:
[0066] Firstly, a standard line segment d l is taken in the object plane and its length is measured by a standard measuring instrument. Standard line segment d l is imaged by the MS-DFI unit and its image d p can be obtained in the imaging sub-aperture image.
[0067] Then, this imaging sub-aperture image is transformed into a 3D sub-aperture image by 3D correction, in which the spherical image of standard line segment d l , namely a short arc d c on the spherical surface can be obtained. The size of d c is quantified in pixels and its corresponding arc angle d θ is obtained. Since the curvature radius R of the spherical optical component can be determined accurately during the process of centering, the corresponding actual size of d c can be deduced by d=Rd θ . By establishing the relationship between d c and d, the relationship between the pixels in the 3D sub-aperture image and the actual size is calibrated, namely the calibration coefficient k=d/d c . If substituting the equation d=Rd θ , we have k=Rd θ /d c . Continuing to substitute the equation d c =R pixel d θ , we can finally deduce calibration coefficient by k=R/R pixel , where R pixel is the curvature radius in pixels of the 3D spherical surface image, called pixel curvature radius for short. To extract the length of surface defects on one spherical optical component, feature extraction is firstly implemented to get each pixel's position coordinates of defects. Then the continuous defects are discretized into a plurality of line segments described by a series of line equations l i : y i =k i x i +b i based on position coordinates, where i=1,2,3 . . . n. After the process of inverse-projection reconstruction for each line segment, the corresponding arc C i of line segment l i on the spherical surface with the curvature radius R pixel is obtained. And the length of defects in pixels can be figured out with the surface integral equation:
[0000]
L
pixel
=
∑
i
=
1
n
(
∫
C
i
ds
)
[0000] where ds refers to the curve differential element. After substituting the calibration coefficient k, the actual length of defects can be obtained by:
[0000]
L
real
=
∑
i
=
1
n
k
i
(
∫
C
i
ds
)
[0068] The defect width calibration data is obtained as follows:
[0069] Firstly, in the 3D coordinate system, a standard line segment is taken in the object plane and its actual width is measured by a standard measuring instruments. The standard line segment is imaged by the MS-DFI unit and its image can be obtained in the imaging sub-aperture image.
[0070] Then, this imaging sub-aperture image is transformed into a 3D sub-aperture image by 3D correction, in which the spherical image of the standard line segment can be obtained. For the spherical image, the arc length in pixels along width direction is the width of defects in pixels. Since the defects are located in the center of FOV during the process of image acquisition at high magnification, information loss along the direction of the optical axis can be ignored. Thus, the actual width of defects is equal to that of the standard line segment.
[0071] Finally, a piecewise fitting for the corresponding discrete points of actual width and width in pixels of defects is used to obtain the best fitting curve, which is as the calibration transfer function (CTF). With the CTF, the actual width at any locations on the spherical surface can be calculated from the width in pixels.
[0072] The present invention achieves the automatic quantitative evaluation for surface defects of spherical optical components, which not only liberates the inspectors from the heavy work of visual inspection, but also considerably enhance the efficiency and precision of the inspection, avoiding the influence of subjectivity on the results. Eventually, reliable numerical basis for the use and process of spherical optical components is provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0073] FIG. 1 is a perspective view of according to a preferred embodiment of the present invention.
[0074] FIG. 1 illustrates a block diagram of surface defects evaluation system and method for spherical optical components in accordance with the first and the second embodiment of the present invention;
[0075] FIG. 2 illustrates a schematic diagram of all parts of surface defects evaluation system and method for spherical optical components in accordance with FIG. 1 in more detail;
[0076] FIG. 3 illustrates a schematic diagram of the structure of the illumination unit in accordance with FIG. 1 ;
[0077] FIG. 4 illustrates a schematic diagram of the illumination light path in accordance with the first embodiment of the present invention;
[0078] FIG. 5 illustrates a graph of the relationship between the curvature radius of the convex spherical optical component and the aperture angle of the illuminant in the case of the incident angle of 40° in accordance with FIG. 4 ;
[0079] FIG. 6 illustrates a schematic diagram of the principle of the microscopic scattering dark-field imaging of the present invention;
[0080] FIG. 7 illustrates a schematic diagram of the structure of the centering unit in accordance with the first embodiment of the present invention;
[0081] FIG. 8A illustrates a schematic diagram of the light path in the case of Z-direction deviation between the positions of the reticle image and the curvature center of the convex spherical optical component in accordance with FIG. 7 ;
[0082] FIG. 8B illustrates an image of the crosshair captured by CCD in the case of Z-direction deviation between the positions of the reticle image and the curvature center of the spherical optical component in accordance with FIG. 7 ;
[0083] FIG. 9A illustrates a schematic diagram of the light path in the case of X-direction and Y-direction deviation between the positions of the reticle image and the curvature center of the convex spherical optical component in accordance with FIG. 7 ;
[0084] FIG. 9B illustrates an image of the crosshair captured by CCD in the case of X-direction and Y-direction deviation between the positions of the reticle image and the curvature center of the convex spherical optical component in accordance with FIG. 7 ;
[0085] FIG. 10 illustrates a block diagram of the control subsystem in accordance with FIG. 1 ;
[0086] FIG. 11A illustrates a schematic diagram of portions of the control subsystem when SSDES operates in centering mode in accordance with FIG. 10 ;
[0087] FIG. 11B illustrates a schematic diagram of portions of the control subsystem when SSDES operates in inspection mode in accordance with FIG. 10 ;
[0088] FIG. 12 illustrates a flowchart of the automatic centering module in accordance with FIG. 1 ;
[0089] FIG. 13A illustrates a graph of image entropy clarity evaluation function in accordance with FIG. 12 ;
[0090] FIG. 13B illustrates a schematic diagram of fitting the trajectory center of the crosshair in accordance with FIG. 12 ;
[0091] FIG. 14 illustrates a schematic diagram of sub-aperture scanning in accordance with FIG. 1 ;
[0092] FIG. 15 illustrates a schematic diagram of the sub-aperture plan model in accordance with FIG. 14 .
[0093] FIG. 16 illustrates a flowchart of the scan-path planning module in accordance with FIG. 14 ;
[0094] FIG. 17 illustrates a flowchart of the image processing module in accordance with FIG. 1 ;
[0095] FIG. 18 illustrates a schematic diagram of the imaging process of the sub-aperture in accordance with FIG. 17 ;
[0096] FIG. 19 illustrates a schematic diagram of the 3D correction of the sub-aperture, image stitching of spherical sub-aperture images and full-aperture projection in accordance with FIG. 17 ;
[0097] FIG. 20 illustrates a schematic diagram of inverse-projection reconstruction of projective sub-aperture images in accordance with FIG. 17 ;
[0098] FIG. 21 illustrates a flowchart of full-aperture projection in accordance with FIG. 17 ;
[0099] FIG. 22 illustrates a flowchart of image stitching of projective sub-apertures in accordance with FIG. 21 ;
[0100] FIG. 23 illustrates a schematic diagram of the process of defect length calibration;
[0101] FIG. 24 illustrates a schematic diagram of the process of defect width calibration;
[0102] FIG. 25 illustrates a graph of the calibration transfer function for width in accordance FIG. 24 ;
[0103] FIG. 26 illustrates a schematic diagram of the illumination light path in accordance with the second embodiment of the present invention;
[0104] FIG. 27 illustrates a graph of the relationship between the curvature radius of the concave spherical optical component and the aperture angle of the illuminant in the case of the incident angle of 40° in accordance with FIG. 26 ;
[0105] FIG. 28 illustrates a schematic diagram of the structure of the centering unit in accordance with the second embodiment of the present invention;
[0106] FIG. 29A illustrates a schematic diagram of the light path in the case of Z-direction deviation between the positions of the reticle image and the curvature center of the concave spherical optical component in accordance with FIG. 28 ;
[0107] FIG. 29B illustrates an image of the crosshair captured by CCD in the case of Z-direction deviation between the positions of the reticle image and the curvature center of the concave spherical optical component in accordance with FIG. 28 ;
[0108] FIG. 30A illustrates a schematic diagram of the light path in the case of X-direction and Y-direction deviation between the positions of the reticle image and the curvature center of the concave spherical optical component in accordance with FIG. 28 ;
[0109] FIG. 30B illustrates an image of the crosshair captured by CCD in the case of X-direction and Y-direction deviation between the positions of the reticle image and the curvature center of the concave spherical optical component in accordance with FIG. 28 ;
[0110] FIG. 31 illustrates a block diagram of surface defects evaluation system and method for spherical optical components in accordance with the third embodiment of the present invention;
[0111] FIG. 32 illustrates a schematic diagram of all parts of surface defects evaluation system and method for spherical optical components in accordance with FIG. 31 in more detail;
[0112] FIG. 33 illustrates a flowchart of the image processing module in accordance with FIG. 31 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0113] Hereinafter, the present invention will now be described in detail with the combination of the accompany drawings and the embodiments.
[0114] The present invention is capable to evaluate the surface defects of both convex and concave spherical optical components. The first embodiment applies to the surface defects evaluation of the convex spherical optical components. The second embodiment applies to the surface defects evaluation of the concave spherical optical components. The third embodiment applies to the surface defects evaluation of the small-aperture spherical optical component. In this case, the evaluation method is much more simplified because only single sub-aperture image is required to obtain dark-field image covering the full-aperture.
[0115] Embodiments of the present invention will be described in detail with reference to the above drawings. In principle, the same components are indicated by the same reference numbers in all drawings for describing the embodiments.
First Embodiment
[0116] Hereafter, a first embodiment of the present invention will be described in detail with reference to FIGS. 1 to 25 , which describes surface defects evaluation system and method for convex spherical optical components.
[0117] FIG. 1 illustrates a block diagram of surface defects evaluation system and method for spherical optical components in accordance with the first and the second embodiment of the present invention. The SSDES 100 comprises a defect imaging subsystem 200 , a control subsystem 700 . The defect imaging subsystem 200 is adapted to acquire microscopic scattering dark-field images suitable for digital image processing. The control subsystem 700 drives the movements of the illumination unit 300 , the MS-DFI unit 400 , the SPPA unit 500 and the centering unit 600 , to acquire images of the inspected surface of the spherical optical component.
[0118] Referring to FIG. 1 , the defect imaging subsystem 200 comprises an illumination unit 300 , an MS-DFI unit 400 , a SPPA unit 500 and a centering unit 600 . The illumination unit 300 is adapted to provide dark-field illumination for the MS-DFI unit 400 . The MS-DFI unit 400 is adapted to collect scatter light induced by the surface and image. The SPPA unit 500 is adapted to achieve five-dimensional spatial position and attitude adjustment including three-dimensional translation, rotation and swing, easy to acquire sharp images at various locations on the surface of the spherical optical component. The centering unit 600 is adapted to analyze the position of the curvature center of the component. The movement and the adjustment of the illumination unit 300 , the MS-DFI unit 400 , the SPPA unit 500 and the centering unit 600 are driven by the control subsystem 700 .
[0119] The illumination unit 300 is adapted to provide dark-field illumination for the MS-DFI unit 400 . Common parallel light source is not suitable for dark-field illumination because the incident light that doesn't pass through the curvature center of the component is reflected by the spherical surface, passes through the MS-DFI unit 400 and becomes a bright-field reflective spot finally, destroying the dark-field illumination condition. Therefore, the illumination unit 300 , which is provided for surface defects inspection for spherical optical components, emits illumination light with the aperture angle varying with the curvature radiuses, providing dark-field illumination for the convex spherical optical component.
[0120] FIG. 3 illustrates a schematic diagram of the structure of the illumination unit 300 in accordance with FIG. 1 . The illumination unit 300 comprises illuminants and an illuminant support bracket 310 . The illuminant comprises a uniform surface light source 320 and a lens group 330 with front fixed lens group 331 , zoom lens group 332 and rear fixed lens group 333 installed in. The optical axis of the lens group 330 intersects with the optical axis of the MS-DFI unit 405 at the incident angle of y ranging from 25 to 45 degrees.
[0121] The illuminant support bracket 310 comprises a top fixation board 311 a hollow shaft 312 , a worm gear 313 , a worm 314 , a servo motor 315 , a motor support 316 , bearings 317 , a rotating cylindrical part 318 and illuminant fixation supports 319 . The illuminant is fixed on the illuminant support bracket 319 which is fixed on the rotating cylindrical part 318 . The rotating cylindrical part 318 has flexible connections with the hollow shaft 312 by the bearings 317 . The worm gear 313 , installed on the rotating cylindrical part 318 has flexible connections with the worm 314 and achieve circular rotation by the drive of the servo motor 315 . The servo motor 315 is fixed on the top fixation board 311 by the motor support 316 and the hollow shaft 312 is also fixed on the top fixation board 311 , which is fixed on the Z-axis translation stage 530 .
[0122] The illuminant support bracket 310 is applied to provide illumination for spherical surface defects in all directions. Three illuminants 301 a , 301 b and 301 c are in annular and uniform distribution at the angle interval of 120° by the illuminant fixation support 319 on the rotating cylindrical part 318 . The servo motor 315 is driven by the illumination rotating control module 721 to achieve annular illumination.
[0123] FIG. 4 illustrates a schematic diagram of the illumination light path in accordance with the first embodiment of the present invention. The parallel light emitted by the uniform surface light source 320 passes through the lens group 330 and becomes convergent spherical wave with the aperture angle of θ l . The detailed process is as follows. The zoom lens group 332 is moved to the position in the lens group 330 calculated according to the curvature radius of the convex spherical optical component 201 . The parallel light emitted by the uniform surface light source 320 enters into the lens group 330 and passes through the front fixed lens group 331 , the zoom lens group 332 and the rear zoom lens group 333 in turn. Finally it becomes convergent spherical wave with the aperture angle of θ l .
[0124] FIG. 5 illustrates a graph of the relationship between the curvature radius of the convex spherical optical component and the aperture angle θ l of the illuminant in the case of the incident angle γ of 40° in accordance with FIG. 4 . It can be found that with the curvature radius increasing, the aperture angle θ l decreases and the illumination range received by the surface also decreases. The aperture angle θ l is less than or equal to 15°.
[0125] Taking advantages of the induced scatter light by the principle that defects on the smooth surface modulate the incident light, the MS-DFI unit 400 achieves microscopic dark-field imaging of defects and acquires dark-field images of defects. The MS-DFI unit 400 is the machine vision module of the SSDES 100 .
[0126] FIG. 6 illustrates a schematic diagram of the principle of the microscopic scattering dark-field imaging of the present invention. The incident light 210 is incident onto the surface of the convex spherical optical component 201 . If the spherical surface is smooth, the incident light 210 , according to the law of reflection in geometrical optics, is reflected on the surface to form the reflected light 212 , which can't enter the MS-DFI unit 400 . If there is defect 203 on the surface of the spherical optical component, the incident light 210 is scattered to form the scatter light 211 , which is received by the MS-DFI unit 400 and forms the dark-field image of defects.
[0127] The SPPA unit 500 is adapted to achieve adjustment of positions and attitude of the convex spherical optical component 201 . FIG. 2 illustrates a schematic diagram of all parts of surface defects evaluation system and method for spherical optical components in accordance with FIG. 1 in more detail. Referring to FIG. 2 , the SPPA unit 500 comprises an X-axis translation stage 510 , a Y-axis translation stage 520 , a Z-axis translation stage 530 , a rotation stage 540 , a swing stage 550 and a self-centering clamp 560 . The swing stage 550 comprises an inner plate and a shell plate. The self-centering clamp 560 has fixed connections with the rotation axis of the rotation stage 540 and the base of the rotation stage 540 is fixed on the inner plate of the swing stage 550 . The inner plate has flexible connections with the shell plate so that the inner plate is capable of swinging by the shell plate. The sections of the inner plate and the shell plate are both in U-shape. The undersurface of the shell plate of the swing stage 550 is fixed on the working surface of the Y-axis translation stage 520 and the Y-axis translation stage 520 is fixed on the working surface of the X-axis translation stage 510 . The X-axis translation stage 510 and the Z-axis translation stage 530 are fixed on the same platform. The illumination unit 300 , the MS-DFI unit 400 and the centering unit 600 are all fixed on the Z-axis translation stage 530 .
[0128] The centering unit 600 provides hardware basis for the automatic centering of the convex spherical optical component 201 . FIG. 7 illustrates a schematic diagram of the structure of the centering unit 600 in accordance with the first embodiment of the present invention. The light beam emitted by the light source 601 of the centering unit 600 passes through the focusing lens group 602 and irradiates the reticle 603 with a crosshair on. Then, the light beam passes through the collimation lens 604 , the beam splitter 605 and the objective 606 and irradiates on the convex spherical optical component 201 . The light beam is reflected on the surface and the image of the crosshair on the reticle 603 is indicated by the reticle image 610 . The reflected light beam passes through the objective 606 again and deflects at the beam splitter 605 . Subsequently, the reflected light beam is reflected by the plane reflector 607 and passes through the imaging lens 608 . Finally, the light beam focuses on the CCD 609 and the CCD 609 acquires the image of the crosshair on the reticle 603 .
[0129] Referring to FIG. 7 , if the incident light beam after passing through the objective 606 focuses on the surface of the convex spherical optical component 201 , the incident light beam and the reflected light beam are symmetric about the optical axis of the centering unit 615 , so the reflected light beam becomes parallel light beam again after passing through the objective 606 the second time and the CCD 609 can acquire sharp crosshair image, which is called the surface image of the crosshair because the image is located on the spherical surface. The position of the surface image in the FOV of the CCD 609 doesn't vary with the slight movement of the convex spherical optical component 201 in X-direction or Y-direction. If the centering unit 600 is moved down to a certain position by the Z-axis translation stage 530 , the incident light beam after passing through the objective 606 focuses on the curvature center of the convex spherical optical component 202 . In this case, the reticle image 610 is located at the curvature center of the convex spherical optical component 202 and the reflected light beam coincides with the incident light beam. The CCD 609 can also acquire sharp crosshair image, which is called the center image of the crosshair because the image is located at the curvature center of the spherical surface. Therefore, the CCD 609 can acquire sharp crosshair images twice, which are named the surface image and the center image respectively. Thus according to the position and clarity of the crosshair image acquired by CCD 609 , the position of the curvature center of the convex spherical optical component 202 can be obtained as follows:
[0130] FIG. 8A illustrates a schematic diagram of the light path in the case of Z-direction deviation between the positions of the reticle image 610 a and the curvature center of the convex spherical optical component 202 in accordance with FIG. 7 . In this case, the reflected light beam doesn't coincide with the incident light beam so that the CCD 609 acquires fuzzy crosshair image, as is illustrated in FIG. 8B . Besides, FIG. 9A illustrates a schematic diagram of the light path in the case of X-direction and Y-direction deviation between the positions of the reticle image 610 b and the curvature center of the convex spherical optical component 202 in accordance with FIG. 7 . In this case, the optical axis of the convex spherical optical component 205 doesn't coincide with the optical axis of the centering unit 615 . The reflected light beam focuses on the CCD 609 so that the CCD 609 acquires sharp crosshair image which is not located in the center of the FOV, as is illustrated in FIG. 9B . Therefore according to the states of crosshair images on the CCD 609 , the 3D-position of curvature center of the convex spherical optical component 202 can be determined.
[0131] The control subsystem 700 is adapted to drive the movements of various parts of the defect imaging subsystem 200 , to realize automatic scanning and inspection of defects on the spherical surface.
[0132] FIG. 10 illustrates a block diagram of the control subsystem 700 in accordance with FIG. 1 . The control subsystem 700 comprises a centering control module 710 , an illumination control module 720 , a five-stage translation control module 730 and an image acquisition control module 740 .
[0133] Referring to FIG. 10 , the centering control module 710 comprises a centering image acquisition unit 711 and a four-stage translation control unit 712 . The centering image acquisition unit 711 is applied to control the CCD 609 of the centering unit 600 to acquire the image of the crosshair and the four-stage translation control unit 712 is applied to control the movement of the X-axis translation stage 510 , the Y-axis translation stage 520 and the Z-axis translation stage 530 and the rotation of the rotation stage 540 during the process of centering.
[0134] Referring to FIG. 10 , the illumination control module 720 comprises an illumination rotating control unit 721 and an illuminant zoom control unit 722 . The illumination rotating control unit 721 is applied to control the rotation of the illuminant support bracket 310 of the illumination unit 300 and the illuminant zoom control unit 722 is applied to control the movement of the zoom lens group 332 to change the aperture angle θ l of the emitted convergent spherical wave.
[0135] Referring to FIG. 10 , the five-stage translation control module 730 is applied to control the movement of the X-axis translation stage 510 , the Y-axis translation stage 520 and the Z-axis translation stage 530 , the rotation of the rotation stage 540 and the swing of the swing stage 550 during the process of inspection.
[0136] Referring to FIG. 10 , the image acquisition control module 740 comprises a sub-aperture image acquisition unit 741 and a microscope zoom control unit 742 . The sub-aperture image acquisition unit 741 is applied to control the MS-DFI unit 400 to acquire sub-aperture images and the microscope zoom control unit 742 is applied to change the image magnification of the MS-DFI unit 400 .
[0137] The SSDES 100 operates in two modes, which are centering mode and inspection mode. FIG. 11A illustrates a schematic diagram of portions of the control subsystem 700 when SSDES 100 operates in centering mode in accordance with FIG. 10 . When the convex spherical optical component 201 is located below the centering unit 600 by the SPPA unit 500 , the SSDES 100 operates in centering mode. In this mode, the control subsystem 700 achieves automatic centering by the centering image acquisition unit 711 and the four-stage translation control unit 712 . The four-stage translation control unit 712 drives the movement of the Z-axis translation stage 530 to make the centering unit 600 focus automatically and accurately along the Z-direction, the movement of the X-axis translation stage 510 and the Y-axis translation stage 520 to realize translation of the convex spherical optical component 201 , and rotation of the rotation stage 540 .
[0138] FIG. 11B illustrates a schematic diagram of portions of the control subsystem 700 when SSDES 100 operates in inspection mode in accordance with FIG. 10 . When the convex spherical optical component 201 is located below the MS-DFI unit 400 by the SPPA unit 500 , the SSDES 100 operates in inspection mode. In this mode, the control subsystem 700 completes full-aperture defects inspection of the convex spherical optical component 201 by the illumination control module 720 , five-stage translation control module 730 and image acquisition control module 740 . The illumination control module 720 comprises an illumination rotating control unit 721 and an illuminant zoom control unit 722 . The illumination rotating control unit 721 is applied to achieve all-direction illumination for surface defects of the convex spherical optical component 201 and the illuminant zoom control unit 722 is applied to achieve dark-field illumination for surface defects of the convex spherical optical component 201 . The five-stage translation control module 730 is applied to drive the convex spherical optical component 201 to precisely adjust the spatial position and posture of the convex spherical optical component 201 for the purpose of full-aperture scanning and inspection. The image acquisition control module 740 comprises a sub-aperture image acquisition unit 741 and amicroscope zoom control unit 742 . The sub-aperture image acquisition unit 741 is applied to acquire the sub-aperture images for the image processing module 1100 and the microscope zoom control unit 742 is applied to automatically change the imaging magnification of the MS-DFI unit 400 .
[0139] The control subsystem 700 is the hub of the SSDES 100 connecting the defect imaging subsystem 200 and the evaluation method 800 . The control subsystem 700 not only precisely controls the defect imaging subsystem 200 , but also delivers images obtained by the defect imaging subsystem 200 and the information of position and state to the evaluation method 800 to process. The control subsystem 700 achieves high-speed delivery and high-efficiency collaborative processing of information between the defect imaging subsystem 200 and the evaluation method 800 , realizes automatic scanning of the convex spherical optical component 201 and increases the inspection efficiency of SSDES 100 .
[0140] The evaluation method 800 comprises an automatic centering module 900 , a scan-path planning module 1000 , an image processing module 1100 and a defect calibration module 1400 .
[0141] The automatic centering module 900 is adapted to achieve automatic centering, accurate measurement of the curvature radius and consistency alignment between the rotation axis 565 and the optical axis of the spherical optical component 205 . The scan-path planning module 1000 is adapted to plan the optimal scan-path for the spherical surface in order that the whole surface can be inspected without omission by sub-apertures as few as possible. The image processing module 1000 is adapted to achieve spherical surface defects inspection with high precision. The defect calibration module 1400 is adapted to establish the relationship between pixels and actual size in sub-aperture images at any locations on the spherical surface in order that the actual size of defects can be obtained.
[0142] The evaluation method 800 comprises the following steps:
[0143] Step1: The implementation of automatic centering of the spherical optical component by the automatic centering module 900 ;
[0144] Step2: the completion of optimal scan-path planning and full-aperture scanning for the spherical optical component by the scan-path planning module 1000 ;
[0145] Step3: the obtainment of spherical surface defect information by the image processing module 1100 and the defect calibration module 1400 .
[0146] The implementation of automatic centering of the spherical surface by the automatic centering module 900 according to Step 1, comprises the accurate measurement of the curvature radius of the convex spherical optical component 201 and axial consistency alignment between the rotation axis 565 and the optical axis of the spherical optical component 205 , providing fiducial position for planning optimal scan-path in Step 2. FIG. 12 illustrates a flowchart of the automatic centering module 900 in accordance with FIG. 1 . Referring to FIG. 12 , the automatic centering module 900 comprises the following steps:
[0147] 1-1. Initialize the centering unit 600 .
[0148] 1-2. Move the convex spherical optical component 201 to the initial position where the optical axis of the spherical optical component 205 coincides with the optical axis of the centering unit 615 approximately.
[0149] 1-3. The Z-axis translation stage 530 is controlled to scan along Z-direction to find the sharpest crosshair image by use of image entropy clarity evaluation function. FIG. 13A illustrates a graph of image entropy clarity evaluation function in accordance with FIG. 12 .
[0150] 1-4. Judge whether the crosshair image is the surface image or the center image as follows:
[0151] Move the X-axis translation stage 510 and Y-axis translation stage 520 slighted to observe whether the crosshair image in the field of view (FOV) is moved with the movement of translation stages or not. If the crosshair image is moved with the movement of stages, it is the center image of the convex spherical optical component 201 and then jump to Step 1-5. Otherwise, it is the surface image of the convex spherical optical component 201 and then jump to Step 1-9.
[0152] 1-5. Move the crosshair image to the center of FOV by the X-axis translation stage 510 and the Y-axis translation stage 520 . After the movement, the optical axis of the convex spherical optical component 205 coincides with the optical axis of the centering unit 615 .
[0153] 1-6. Find the position of the rotation axis 565 by rotation measurement in optical alignment as follows:
[0154] The convex spherical optical component 201 can rotate around the rotation axis of the rotation stage 540 under the self-centering clamp 560 . Every 30° rotation of the rotation stage 540 , CCD 609 acquires a crosshair image. The positions of the crosshair images in the FOV of CCD 609 vary with different rotation angles. The trajectory formed by the center of the crosshair is close to a circle. FIG. 13B illustrates a schematic diagram of fitting the trajectory center of the crosshair in accordance with FIG. 12 . Referring to FIG. 13B , the center 910 is the position of the rotation axis 565 .
[0155] 1-7. Obtain the trajectory center by the least square circle fitting method and the max deviation between the trajectory center and the crosshair center is calculated.
[0156] 1-8. Judge whether the max deviation is lower than the max permissible error. If the max deviation is lower than the max permissible error, the axial consistency alignment is considered completed. Otherwise, the optical axis of the spherical optical component 205 is not coincident with the rotation axis 565 , therefore the center of the crosshair image is moved to the fitting trajectory center 910 by adjusting the self-centering clamp 560 and then jump to Step 1-5.
[0157] 1-9. Move the Z-axis translation stage 530 to image at theoretical curvature center obtained by initialization. The Z-axis translation stage 530 is controlled to scan along Z-direction to find the sharpest crosshair image and then jump to Step 1-5. At the same time, Z-direction displacement from the position of the surface image to the position of the center image is recorded to get the real curvature radius of the convex spherical optical component 201 , which is the displacement of the Z-axis translation stage 530 .
[0158] During the process of centering, the self-centering clamp 560 is adjusted to move the center of the crosshair image to the trajectory center in order that the optical axis of the convex spherical optical component 205 coincides with the rotation axis 565 . The X-axis translation stage 510 and the Y-axis translation stage 520 are adjusted to move the crosshair image to the center of the FOV of the CCD 609 in order that the optical axis of the convex spherical optical component 205 coincides with the optical axis of the centering unit 615 . After the above adjustment, the optical axis of the convex spherical optical component 205 , the rotation axis 565 and the optical axis of the centering unit 615 are in consistency. In this case, the position of the convex spherical optical component 201 is the fiducial position for planning optimal scan-path.
[0159] FIG. 14 illustrates a schematic diagram of sub-aperture scanning in accordance with FIG. 1 . Referring to FIG. 14A-14F , the completion of optimal scan-path planning and full-aperture scanning for the spherical optical component by the scan-path planning module 1000 according to Step 2, comprises the following steps:
[0160] 2-1. With the fiducial position obtained in the process of axial consistency alignment in Step 1, the convex spherical optical component 201 is moved by the SSPA unit 500 below the MS-DFI unit 400 . Then the MS-DFI unit 400 acquires sub-aperture 1010 located at the vertex of the spherical surface 1009 , as is illustrated in FIG. 14A . For the convenience of the following statement, spherical coordinate system X s Y s Z s is defined here, whose origin O s 1004 s is located at the curvature center of the convex spherical optical component 201 and the z-axis Z s 1003 s passes through the vertex of the spherical surface 1009 . To achieve the full-aperture sampling, two-dimension movements along the meridian and parallel scanning trajectory is required, combining the swing around X s 1001 s and the rotation around Z s 1003 s .
[0161] 2-2. The convex spherical optical component 201 is driven to swing around X s 1001 s with swing angle β 1 1007 a , one sub-aperture 1020 is acquired on meridian 1005 , as is illustrated in FIG. 14B . After that, rotating around Z s 1003 s with rotation angle α 1 1008 a is implemented to acquire another sub-aperture 1020 a on parallel 1006 a , as is illustrated in FIG. 14C .
[0162] 2-3. Every time after the rotation around Z s 1003 s with the same rotation angle α 1 1008 a , one sub-aperture is acquired so that multiple sub-apertures on parallel 1006 a are obtained, as is illustrated in FIG. 14D .
[0163] 2-4. After the completion of sub-aperture acquisition on parallel 1006 a , the convex spherical optical component 201 is driven to swing around X s 1001 s again with swing angle β 2 1007 b , then one sub-aperture 1030 is acquired on meridian 1005 .
[0164] 2-5. Every time after the rotation around Z s 1003 s with the same rotation angle α 2 1008 b , one sub-aperture is acquired so that multiple sub-apertures on parallel 1006 b are obtained, as is illustrated in FIG. 14F . Full-aperture sampling is finished with several times repetition of such a process that the convex spherical optical component 201 is driven to swing around X s 1001 s with swing angle β 2 1007 b to acquire multiple sub-apertures on next parallel after the completion of sub-aperture acquisition on this parallel.
[0165] FIG. 15 illustrates a schematic diagram of the sub-aperture plan model in accordance with FIG. 14 . Referring to FIG. 15 , the sub-aperture plan model is established firstly in order that the whole surface can be inspected without omission by sub-apertures as few as possible. In this model, sub-aperture 1020 and sub-aperture 1030 are two adjacent sub-apertures on meridian 1005 . Sub-aperture 1020 a is adjacent to sub-aperture 1020 on parallel 1006 a where sub-aperture 1020 is located. Similarly, sub-aperture 1030 a is adjacent to sub-aperture 1030 on parallel 1006 b where sub-aperture 1030 is located. Besides, the bottom intersection of sub-aperture 1020 and sub-aperture 1020 a (the intersection far from the vertex of the spherical surface 1009 ) is indicated by P cd 1040 a , the top intersection of sub-aperture 1030 and sub-aperture 1030 a (the intersection near the vertex of the spherical surface 1009 ) is indicated by P cu 1040 b . So the sufficient conditions for the realization of sub-aperture no-leak inspection is that the arc length 1045 b is less than or equal to the arc length 1045 a . Under such a constraint, planning result can be solved and obtained by establishing the relationship between swing angle β 1 1007 a , swing angle β 2 1007 b and rotation angle α 1 1008 a , rotation angle α 2 1008 b .The solution procedure of swing angle β 1 1007 a , swing angle β 2 1007 b , rotation angle α 1 1008 a and rotation angle α 2 1008 b is as follows:
[0166] {circle around (1)} Validate relevant parameters about the convex spherical optical component 201 , including the curvature radius, aperture of the convex spherical optical component 201 and the size of the object field of view of the MS-DFI unit 400 .
[0167] {circle around (2)} Specify the initial value of swing angle β 1 1007 a and swing angle β 2 1007 b according to the above three parameters. After that, calculate the value of rotation angle α 2 1008 a and rotation angle α 2 1008 b according to the same overlapping area between adjacent sub-apertures on one parallel. Then, figure out arc length 1045 b and arc length 1045 a.
[0168] {circle around (3)} Compare arc length 1045 b and arc length 1045 a to determine whether the given initial value of swing angle β 2 1007 b is appropriate or not. If > reduce the value of swing angle β 2 1007 b by 5% and then jump to Step {circle around (2)}. Otherwise, sub-aperture plan for covering the entire spherical surface is finished.
[0169] FIG. 17 illustrates a flowchart of the image processing module 1100 in accordance with FIG. 1 . Referring to FIG. 17 , the obtainment of spherical surface defects information by the image processing module 1100 and the defect calibration module 1400 according to Step 3, comprises the following steps:
[0170] 3-1. The imaging sub-aperture image is a 2D image, which is obtained when the surface of the convex spherical optical component 201 is imaged by the MS-DFI unit 400 in the image plane. Due to the information loss along the direction of optical axis during the optical imaging process, 3D correction of sub-apertures should be conducted firstly to recover the information loss of surface defects of the convex spherical optical component 201 along the direction of optical axis during the optical imaging process.
[0171] 3-2. For convenience of feature extraction, 3D sub-aperture images obtained after 3D correction of sub-apertures are projected onto a 2D plane with the full-aperture projection to obtain the full-aperture projective image.
[0172] 3-3. Feature extraction at low magnification is conducted on the full-aperture projective image; then 3D sizes of defects is obtained with inverse-projection reconstruction; finally, actual sizes and positions of surface defects on the convex spherical optical component 201 are obtained taking advantages of the defect calibration data got with the calibration module 1400 .
[0173] 3-4. Defects are inspected at high magnification to guarantee the micron-scale inspection precision. First, the imaging magnification of the MS-DFI unit 400 is zoomed to high magnification; then, according to the positions obtained by Step 3-3, surface defects are moved to the center of the object field of view to acquire images at high magnification; Finally, feature extraction at high magnification is conducted and micron-scale evaluation results of defects are obtained taking advantages of the defect calibration data got with the calibration module 1400 .
[0174] 3-5. Evaluation results are output in the form of 3D panoramic preview of the spherical surface, electronic report and defect location map.
[0175] FIG. 18 illustrates a schematic diagram of the imaging process of the sub-aperture in accordance with FIG. 17 . According to Step 3-1, imaging sub-aperture images are obtained when the surface of the convex spherical optical component 201 is imaged by MS-DFI unit 400 in the image plane. Referring to FIG. 17 , the detailed description is as follows:
[0176] 3-1-1. According to the optimal scan-path planned by the scan-path planning module 1000 in Step 2, one point p 1201 on the surface of the convex spherical optical component 201 is moved to the point p′ 1202 by the SPPA unit 500 , as is illustrated by Procedure 1261 in FIG. 18 .
[0177] 3-1-2. The MS-DFI unit 400 acquires sub-apertures at low magnification. Point p′ 1202 is imaged to be image point p″ 1211 in the imaging sub-aperture image 1210 by the MS-DFI unit 400 , as is illustrated by Procedure 1263 in FIG. 18 .
[0178] 3-1-3. During the process of digital image acquisition, the image-plane coordinate system X c Y c is transformed into the image coordinate system X i Y i and imaging sub-aperture image 1210 obtained, as is illustrated by Procedure 1263 in FIG. 18 . Referring to FIG. 18 , X-axis X c 1001 c and y-axis Y c 1002 c compose the image-plane coordinate system X c Y c , whose origin O c 1004 c is located at the intersection of the optical axis of the MS-DFI unit 405 and the imaging sub-aperture image 1210 . X-axis X i 1001 i and y-axis Y i 1002 i compose the image coordinate system X i Y i , whose origin O i 1004 i is located at the top left corner of the digital image.
[0179] As is illustrated by Procedure 1264 in FIG. 19 , 3D correction of sub-apertures according to Step 3-1 means that the imaging process of MS-DFI unit 400 is simplified to be a pin-hole model and imaging sub-aperture image 1210 are transformed into 3D sub-aperture image 1220 with geometrical relationship.
[0180] FIG. 19 illustrates a schematic diagram of the 3D correction of the sub-aperture, image stitching of spherical sub-aperture images and full-aperture projection in accordance with FIG. 17 . FIG. 21 illustrates a flowchart of full-aperture projection in accordance with FIG. 17 . According to Step 3-2, the full-aperture projective image is obtained. Referring to FIG. 19 and 21 , the detailed description is as follows:
[0181] 3-2-1. 3D sub-aperture image 1220 is transformed into spherical sub-aperture image 1230 by global coordinate transformation, as is illustrated by Procedure 1265 in FIG. 19 .
[0182] 3-2-2. Spherical sub-aperture image 1230 is projected vertically onto the plane to obtain projective sub-aperture image 1240 , as is illustrated by Procedure 1266 in FIG. 19 . In this way, data volume describing one sub-aperture is reduced so that computations of the following feature extraction can be largely simplified.
[0183] 3-2-3. In terms of inspection for surface defects of the convex spherical optical component 201 involving multiple sub-apertures, perfect stitching should be carried out before extracting sizes and positions of defects. Since it is difficult to extract sizes and positions of defects in three-dimensional space, spherical sub-aperture image 1230 is projected vertically onto the plane to obtain projective sub-aperture image 1240 . Projective sub-aperture images are stitched and sizes and positions of defects are extracted in the plane. Precise inspection for surface defects of the convex spherical optical component 201 can be achieved by inverse-projection reconstruction.
[0184] The way of direct stitching for parallel circle and annulus stitching for meridian circle is used for image stitching of projective sub-aperture images. FIG. 22 illustrates a flowchart of image stitching of projective sub-apertures in accordance with FIG. 21 . Referring to FIG. 22 , the process of image stitching of projective sub-aperture images is as follows:
[0185] {circle around (1)} Projective sub-aperture images are denoised to remove the effect of background noise on stitching accuracy.
[0186] {circle around (2)} After denoising, image registration according to overlapping area is carried out on adjacent projective sub-aperture images on the same parallel circle.
[0187] {circle around (3)} Adjacent projective sub-aperture images after registration on the same parallel circle are stitched to obtain the annulus image of one parallel circle.
[0188] {circle around (4)} The minimum annulus image containing all overlapping areas is extracted.
[0189] {circle around (5)} The image registration points of the minimum annulus image are extracted to acquire the best registration location, so that the image stitching of projective sub-aperture images is finished.
[0190] Referring to FIG. 19 , during the process of vertical projection, spherical sub-aperture image 1230 after global coordinate transformation has difference in deformation and compression of defects. Thus, during the following process of feature extraction at low magnification, inverse-projection reconstruction is needed to recover the deformation and compression due to the vertical projection of spherical sub-aperture image 1230 .
[0191] According to Step 3-3, feature extraction at low magnification is conducted on the full-aperture projective image; then, 3D sizes of defects is obtained within verse-projection reconstruction; finally, actual sizes and positions of surface defects of the spherical optical component are obtained taking advantages of the defect calibration data got with defect calibration module 1400 . The detailed description is as follows.
[0192] 3-3-1. Extract features of the 2D full-aperture image after image stitching of projective sub-aperture images to obtain sizes and positions of defects.
[0193] 3-3-2. Obtain 3D sizes and positions in pixels of surface defects of the convex spherical optical component 201 by inverse-projection reconstruction, as is illustrated by Procedure 1267 in FIG. 20 .
[0194] 3-3-3. Taking advantages of the defect calibration data got with the defect calibration module 1400 , convert 3D sizes and positions in pixels to actual sizes and positions.
[0195] The defect calibration data according to Step 3-3 and Step 3-4 comprises defect length calibration data and defect width calibration data. The sizes and position coordinates of defects are quantified in pixels after image processing module 1100 , thus the defect calibration module 1400 is needed to establish the relationship between actual sizes of line segments at any locations on the spherical surface and corresponding pixels in sub-aperture images for purpose of actual lengths, widths and position coordinates of defects.
[0196] The process of defect length calibration is to establish the relationship between actual lengths of line segments at any locations on the spherical surface and corresponding pixels in spherical sub-aperture images. FIG. 23 illustrates a schematic diagram of the process of defect length calibration. Referring to FIG. 23 , The defect length calibration data is obtained as follows:
[0197] Firstly, a standard line segment d l 1420 is taken in the object plane 1250 and its length is measured by a standard measuring instrument. Standard line segment d l 1420 is imaged by MS-DFI unit 400 and its image d p 1410 can be obtained in the imaging sub-aperture image 1210 .
[0198] Then, this imaging sub-aperture image 1210 is transformed into a 3D sub-aperture image 1220 by3D correction, in which the spherical image of standard line segment d l 1420 , namely a short arc d c 430 on the spherical surface can be obtained. The size of d c 1430 is quantified in pixels and its corresponding arc angle d θ 1440 is obtained. Since the curvature radius R of the convex spherical optical component 201 can be determined accurately during the process of centering, the corresponding actual size of d c 1430 can be deduced by d=Rd θ . By establishing the relationship between d c and d, the relationship between the pixels in the 3D sub-aperture image 1220 and the actual size is calibrated, namely the calibration coefficient k=d/d c .If substituting the equation d=Rd θ , we have k=Rd θ /d c .Continuing to substitute the equation d c =R pixel d θ , we can finally deduce calibration coefficient by k=R/R pixel , where R pixel is the curvature radius in pixels of the 3D spherical surface image, called pixel curvature radius for short. Thus it can be seen that the calibration coefficient k varies with the curvature radius R and calibration should be carried out again if the curvature radius R changes.
[0199] To extract the length of surface defects on one spherical optical component, feature extraction is firstly implemented to get each pixel's position coordinates of defects. Then the continuous defects are discretized into a plurality of line segments described by a series of line equations l i : y i =k i x i +b i based on position coordinates, where i=1,2,3 . . . n. After the process of inverse-projection reconstruction for each line segment, the corresponding arc C i of line segment l i on the spherical surface with the curvature radius R pixel is obtained. And the length of defects in pixels can be figured out with the surface integral equation:
[0000]
L
pixel
=
∑
i
=
1
n
(
∫
C
i
ds
)
[0000] where ds refers to the curve differential element. After substituting the calibration coefficient k, the actual length of defects can be obtained by:
[0000]
L
real
=
∑
i
=
1
n
k
i
(
∫
C
i
ds
)
[0200] The purpose of width calibration is to establish the relationship between actual length of standard line segments at any locations on the spherical surface and corresponding pixels in 3D sub-aperture images. When MS-DFI unit 400 works at low magnification, the width in micron-scale is difficult to be calibrated accurately due to its small FOV and low resolution. So the width calibration results obtained at low magnification could not be used for evaluation, but only for reference. Defects width should be calibrated and evaluated at high magnification. At low magnification, the method similar to that for the process of length calibration is applied to the process of width calibration. FIG. 24 illustrates a schematic diagram of the process of defect width calibration. At high magnification, referring to FIG. 24 , since defects width is in micron-scale and defects are located in the center of the FOV,the defect width calibration data is obtained as follows:
[0201] Firstly, in the 3D coordinate system, a standard line segment is taken in the object p 1 ane 1250 and its actual width 1420 w is measured by a standard measuring instruments. The standard line segment is imaged by the MS-DFI unit 400 and its image can be obtained in the imaging sub-aperture image 1210 with imaging width 1410 w in pixels.
[0202] Then, this imaging sub-aperture image 1210 is transformed into 3D sub-aperture image 1220 by 3D correction, in which the spherical image of the standard line segment can be obtained. For the spherical image, the arc length 1430 w in pixels along width direction is the width of defects in pixels.
[0203] Since the defects are located in the center of FOV during the process of image acquisition at high magnification, information loss along the direction of the optical axis can be ignored. Thus, the actual width of defects is equal to the width of the standard line segment 1420 w.
[0204] FIG. 25 illustrates a graph of the calibration transfer function for width in accordance FIG. 24 .
[0205] Finally, a piecewise fitting for the corresponding discrete points 1450 for actual width and width in pixels of defects is used to obtain the best fitting curve, which is as the calibration transfer function (CTF) 1460 . With the CTF 1460 , the actual width at any locations on the spherical surface can be calculated from the width in pixels.
Second Embodiment
[0206] Hereafter, a second embodiment of the present invention will be described in detail with reference to FIGS. 26 to 30 , which describes surface defects evaluation system and method for concave spherical optical components.
[0207] Surface defects evaluation system and method for concave spherical optical components described in the second embodiment of the present invention is similar to that for convex spherical optical components described in the first embodiment of the present invention. In order to avoid confusion and repetition, parts in FIGS. 26 to 30 which are relevant to parts in FIGS. 1 to 25 are indicated by the same reference numbers. Emphasis in the second embodiment is also put on parts different from the first embodiment.
[0208] FIG. 26 illustrates a schematic diagram of the illumination light path in accordance with the second embodiment of the present invention. The parallel light emitted by the uniform surface light source 320 passes through the lens group 330 and becomes convergent spherical wave with the aperture angle of θ l . The detailed process is as follows. The zoom lens group 332 is moved to the position in the lens group 330 calculated according to the curvature radius of the concave spherical optical component 1501 . The parallel light emitted by the uniform surface light source 320 enters into the lens group 330 and passes through the front fixed lens group 331 , the zoom lens group 332 and the rear zoom lens group 333 in turn. Finally it becomes convergent spherical wave with the aperture angle of θ l .
[0209] FIG. 27 illustrates a graph of the relationship between the curvature radius of the concave spherical optical component and the aperture angle θ l of the illuminant in the case of the incident angle γ of 40° in accordance with FIG. 26 . It can be found that with the curvature radius increasing, the aperture angle θ l decreases and the illumination range received by the surface also decreases. The aperture angle θ l is less than or equal to 12°. Comparing FIG. 27 with FIG. 5 , it can be seen that the aperture angle formed by illuminants' irradiating on the concave spherical optical component is smaller than that formed by illuminants' irradiating on the convex spherical optical component with the same curvature radius, the aperture angle decreases with the curvature radius increasing more sharply and the critical curvature radius corresponding with the aperture angle of 0° is smaller.
[0210] FIG. 28 illustrates a schematic diagram of the structure of the centering unit 600 in accordance with the second embodiment of the present invention. The light path during the process of centering for the concave spherical optical component 1501 is similar to that during the process of centering for the convex spherical optical component 201 . According to the position and clarity of the crosshair image, the relative position of the curvature center of the concave spherical optical component 1502 to the reticle image 1710 can be obtained as follows:
[0211] FIG. 29A illustrates a schematic diagram of the light path in the case of Z-direction deviation between the positions of the reticle image 1710 a and the curvature center of the concave spherical optical component 1502 in accordance with FIG. 28 . In this case, the reflected light beam doesn't coincide with the incident light beam so that the CCD 609 acquires fuzzy crosshair image, as is illustrated in FIG. 29B . Besides, FIG. 30A illustrates a schematic diagram of the light path in the case of X-direction and Y-direction deviation between the positions of the reticle image 1710 b and the curvature center of the concave spherical optical component 1502 in accordance with FIG. 28 . In this case, the optical axis of the concave spherical optical component 1502 doesn't coincide with the optical axis of the centering unit 615 . The reflected light beam focuses on the CCD 609 so that the CCD 609 acquires sharp crosshair image which is not located in the center of the FOV, as is illustrated in FIG. 30B . Therefore according to the states of crosshair images on the CCD 609 , the 3D-position of curvature center of the concave spherical optical component 1502 can be determined. The second embodiment of the present invention describes surface defects evaluation system and method for concave spherical optical components. The evaluation method for concave spherical optical components is the same as that described in the first embodiment. The illumination unit 300 and the centering unit 600 is different from those for convex spherical optical components due to the difference in surface shape.
Third Embodiment
[0212] Hereafter, a third embodiment of the present invention will be described in detail with reference to FIGS. 31 to 33 , which describes surface defects evaluation system and method for the small-aperture spherical optical components. Similarly, in order to avoid confusion and repetition, parts in FIGS. 31 to 33 which are relevant to parts in FIGS. 1 to 25 are indicated by the same reference numbers. Emphasis in the third embodiment is also put on parts different from the first embodiment.
[0213] The small-aperture spherical optical component 1801 is characterized by that its aperture is smaller than the illumination aperture of the illumination unit 300 and the object field of view of the MS-DFI unit 400 . Thus, the MS-DFI unit 400 needs to acquire only one sub-aperture located at the vertex of the spherical surface 1009 (as is illustrated in FIG. 15 ), which is the full-aperture image covering the whole surface of the small-aperture spherical optical components. Referring to FIGS. 31 to 33 , surface defects evaluation system and method for small-aperture spherical optical components described in the third embodiment doesn't need the scan-path planning module and the image processing module 2000 only need to process one single sub-aperture. Correspondingly, the evaluation method 1900 is easier than that applied to the first and the second embodiment.
[0214] FIG. 31 illustrates a block diagram of surface defects evaluation system and method for small-aperture spherical optical components in accordance with the third embodiment of the present invention. FIG. 32 illustrates a schematic diagram of all parts of surface defects evaluation system and method for small-aperture spherical optical components in accordance with FIG. 31 in more detail. Referring to FIG. 31 and 32 , the evaluation method 1900 comprises an automatic centering module 900 , an image processing module 2000 and a defect calibration module 1400 . The evaluation method 1900 comprises the following steps:
[0215] Step1. The implementation of automatic centering of the spherical optical component by the automatic centering module 900 .
[0216] Step2. The obtainment of spherical surface defect information by the image processing module 2000 and the defect calibration module 1400 .
[0217] FIG. 33 illustrates a flowchart of the image processing module 2000 in accordance with FIG. 31 . Referring to FIG. 33 , the obtainment of spherical surface defects information by the image processing module 2000 and the defect calibration module 1400 according to Step 2, comprises the following steps:
[0218] 2-1. The imaging sub-aperture image is a 2D image, which is obtained when the surface of the small-aperture spherical optical component 1801 is imaged by the MS-DFI unit 400 in the image plane. 3D correction of sub-apertures should be conducted firstly to recover the information loss of surface defects of the small-aperture spherical optical component 1801 along the direction of optical axis during the optical imaging process.
[0219] 2-2. For convenience of feature extraction, 3D sub-aperture images obtained after 3D correction of sub-apertures are projected onto a 2D plane with the single sub-aperture projection to obtain the single sub-aperture projective image.
[0220] 2-3. Feature extraction at low magnification is conducted on the single sub-aperture projective image; then 3D sizes of defects is obtained with inverse-projection reconstruction; finally, actual sizes and positions of surface defects on the small-aperture spherical optical component 1801 are obtained taking advantages of the defect calibration data got with the calibration module 1400 .
[0221] 2-4. Defects are inspected at high magnification to guarantee the micron-scale inspection precision. First, the imaging magnification of the MS-DFI unit 400 is zoomed to high magnification; then, according to the positions obtained by Step 2-3, surface defects are moved to the center of the object field of view to acquire images at high magnification; Finally, feature extraction at high magnification is conducted and micron-scale evaluation results of defects are obtained taking advantages of the defect calibration data got with the calibration module 1400 .
[0222] 2-5. Evaluation results are output in the form of 3D panoramic preview of the spherical surface, electronic report and defect location map.
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A defects evaluation system and method are provided in the present invention. Based on the principle of the microscopic scattering dark-field imaging, the present invention implements a sub-aperture scanning for the surface of spherical optical components and then obtains surface defects information with image processing. Firstly, the present invention takes full advantage of the characteristic that the surface defects of spherical optical components can generate scattering light when an annular illumination beam irradiates on the surface, to implement the sub-aperture scanning and imaging that covers the entire spherical surface. Then, a series of procedures such as the global correction of sub-apertures, the 3D stitching, the 2D projection and the digital feature extraction are taken to inspect spherical surface defects. Finally, actual size and position information of defects are evaluated quantitatively with the defects calibration data. The present invention achieves the automatic quantitative evaluation for surface defects of spherical optical components, which considerably enhance the efficiency and precision of the inspection, avoiding the influence of subjectivity on the results. Eventually, reliable numerical basis for the use and process of spherical optical components is provided.
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TECHNICAL FIELD OF THE INVENTION
The invention relates in general to systems and methods for configuring conductors within an integrated circuit. More specifically, it relates to providing a stable semiconductor device power network by reducing impedance variation within metal power lines caused by connection-bumps on the semiconductor device.
BACKGROUND OF THE INVENTION
The demand for faster and smaller microelectronic devices is driving continual shrinkage of microelectronic architectures. Such microelectronic architectures form the electronic circuits of semiconductor devices. Semiconductor devices are manufactured on silicon wafers using a process of adding layers and selectively removing parts of the layers. Semiconductor device features are created through this selective removal process. Upon the completion of the manufacturing process, the silicon wafers are cut into individual dies where each die includes at least one complete semiconductor device.
Individual dies are not typically directly integrated into electronic devices, such as, for example, cellular phones. Typically, the dies are first packaged. Thus, semiconductor devices may include connection-bumps which function to electrically couple the semiconductor device with its respective package. Once these connection-bumps have coupled a semiconductor device to a package, the packaged semiconductor device may be inserted into and used by an electronic device.
Included among the layers which comprise a semiconductor device is at least one layer of conductors, such as metal lines. Metal lines may be used within the semiconductor device to connect elements of the integrated circuit. For example, metal lines may carry electrical current to and from logic gates. Also, a power network for the semiconductor device may include metal lines. Due to the continued-shrinkage of microelectronic architectures, optimal semiconductor device operation depends upon optimal performance of each semiconductor feature. Thus, stable functionality of the metal lines contributes to optimal functionality of the semiconductor device. However, the connection-bumps which electrically couple a semiconductor device to a package may affect performance of the semiconductor device. In particular, the impedance of conductive device features can be affected by the presence and/or operation of connection-bumps. For example, a metal line traversing an area with a high connection-bump density may have impedance which differs significantly from that of a similar metal line traversing an area with a lower connection-bump density. Because varying line impedance can negatively affect semiconductor device performance, it is desirable to reduce such variation in line impedance. Therefore, a need exists for improved methods of configuring semiconductor devices, and improved semiconductor devices.
SUMMARY OF THE INVENTION
Methods and devices yielding improved semiconductor devices are disclosed. In particular, line impedance variation induced by the presence of connection-bumps may be reduced by configuring impedance-reducing metal lines according to connection-bump densities.
The present invention relates to a semiconductor device, and more particularly, to adding conductors to a semiconductor device having connection-bumps used for device packaging terminations. Presented are improved semiconductor systems and methods for configuring conductors to reduce impedance variation caused by proximity and/or density and/or operation of connection-bumps. The invention includes adding impedance-reducing conductive features which may add no additional functionality to the semiconductor device. The added features may be arranged in areas of sparse connection-bump density. Impedance-reducing conductive features may include metal lines added between functional metal lines, with placement between adjacent functional lines varying by respective embodiment. Impedance-reducing conductive features may be added to any one or combination of conductive layers, and added features may act upon any one or combination of functional features. Further, added features may be electrically active and responsive to semiconductor device operation. Also, methods for determining connection-bump density, which methods may be automated.
In one embodiment, a semiconductor device having at least one functional conductor and at least one impedance-reducing conductor adapted to reduce impedance variation in the at least one functional conductor. The at least one functional conductor is configured to hold an electric potential. The functional conductors may include functional metal lines, and the impedance-reducing conductors may include impedance-reducing metal lines. The device may include connection bumps, and the impedance-reducing metal lines may be arranged where the connection bumps are sparsely distributed.
In another embodiment, a semiconductor device having connection-bumps where at least one connection-bump is configured to hold an electric potential. The connection bumps are arranged sparsely in some areas and densely in other areas. The semiconductor device also includes a plurality of functional metal lines where at least one functional metal line is coupled to the at least one connection-bump holding an electric potential. Finally, the semiconductor device also includes a plurality of impedance-reducing metal lines configured to reduce impedance variation of at least one functional metal line. In the embodiment, the impedance-reducing metal lines may be arranged substantially within a sparse area and parallel with adjacent functional metal lines. Each impedance-reducing metal line may be equidistant from a corresponding functional metal line.
In one embodiment, a method of reducing impedance variation in a semiconductor device which includes forming at least one functional conductor and forming at least one impedance-reducing conductor configured to reduce impedance variation of the at least one functional conductor. In the embodiment, forming conductors may include forming metal lines. The embodiment may also include forming connection bumps. The impedance-reducing metal lines and the connection-bumps may not be equally distributed across the semiconductor device, and their respective distributions may be inversely related. Also, the impedance-reducing lines may be formed having corresponding functional metal lines.
A technical advantage of the invention is the ability to stabilize the power network. For example, semiconductor devices using connection-bumps for I/O and power connections may have connection-bumps over the majority of the semiconductor device. However, some constraints prevent arranging connection-bumps in all areas of the semiconductor device. Such areas having a lower density of power bumps generally have bigger power bounce during semiconductor device operation, and such power bounce leads to semiconductor device malfunction.
This invention provides the ability to normalize metal line impedance in view of semiconductor features or operational characteristics which may influence impedance. Such equalized line impedance may reduce excessive voltage-drop which may interfere with semiconductor device function. For example, logic gate operation and/or device timing may be affected by excessive voltage drop. Therefore, excessive power bounce may be eliminated through use of this invention.
These, and other, aspects of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. The following description, while indicating various embodiments of the invention and numerous specific details thereof, is given by way of illustration and not of limitation. Many substitutions, modifications, additions or rearrangements may be made within the scope of the invention, and the invention includes all such substitutions, modifications, additions or rearrangements.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings accompanying and forming part of this specification are included to depict certain aspects of the invention. A clearer impression of the invention, and of the components and operation of systems provided with the invention, will become more readily apparent by referring to the exemplary, and therefore nonlimiting, embodiments illustrated in the drawings, wherein identical reference numerals designate the same components. Note that the features illustrated in the drawings are not necessarily drawn to scale.
FIG. 1 is a diagram illustrating a semiconductor device with connection-bumps.
FIG. 2 is a diagram illustrating one embodiment of a metal line configuration according to the invention.
FIG. 3 is a diagram illustrating another embodiment of a metal line configuration according to the invention.
FIG. 4 is a diagram illustrating yet another embodiment of a metal line configuration according to the invention.
FIG. 5 is a diagram illustrating one method to differentiate connection-bump density according to the invention.
FIG. 6 is a diagram illustrating another method to differentiate connection-bump density according to the invention.
FIG. 7 is a diagram illustrating yet another method to differentiate connection-bump density according to the invention.
FIG. 8 is a diagram illustrating yet another method to differentiate connection-bump density according to the invention.
DETAILED DESCRIPTION
The invention and the various features and advantageous details thereof are explained more fully with reference to the nonlimiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well known starting materials, processing techniques, components and equipment are omitted so as not to unnecessarily obscure the invention in detail. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only and not by way of limitation. After reading the specification, various substitutions, modifications, additions and rearrangements will become apparent to those skilled in the art from this disclosure which do not depart from the scope of the appended claims.
FIG. 1 is a diagram illustrating one embodiment of a semiconductor device with connection-bumps. Shown in FIG. 1 is a plan view of a semiconductor device 10 having a die edge 12 . A semiconductor device may also be referred to as a die. The device features of die 10 are contained within die edge 12 . Numerous connection-bumps 13 and 15 are shown within die edge 12 . Not shown are all other various device features of semiconductor device 10 . These other various device features are usually fabricated within their respective various process layers prior to the fabrication of connection-bumps 13 and 15 .
Semiconductor device 10 may include a microprocessor. Further, semiconductor device 10 may be a multi-core microprocessor (e.g., a microprocessor having multiple processing units). Semiconductor device 10 may operate at frequencies of greater than about 1 GHz. Semiconductor device 10 may be fabricated using any number of process technologies. In particular, semiconductor device 10 may be fabricated with a process technology having a minimum half pitch of less than about 90 nm.
Semiconductor device 10 may be incorporated into a package prior to use in an electronic device. Connection bumps 13 and 15 enable the semiconductor device to be electrically coupled to a package. Such a package includes electrical leads which enable the package to be electrically coupled with an electrical device. In this manner, a packaged semiconductor device may be in electrical communication with an electronic device. Thus, packaging enables the semiconductor device to be incorporated into and used by an electronic device.
As electrical coupling with an electronic device is enabled via connection bumps 13 and 15 , it follows that connection bumps 13 and 15 may hold electric potential and/or may carry electric current. Thus, connection-bumps may include power connection-bumps which hold electric potential and signal connection-bumps which carry electric signals. Connection bumps 13 and 15 may be considered power connection-bumps. Connection-bumps 13 and 15 include VDD bumps 15 , where VDD may be the power supplied to the semiconductor device 10 . The conductors configured to supply VDD to semiconductor device 10 may be referred to collectively as a power network. The power network may include conductors arranged throughout semiconductor device 10 . It is desirable to maintain a stable voltage on the power network. Connection-bumps 13 and 15 also include GND bumps 13 , where GND may be the common ground for the semiconductor device 10 . It is noted that the plan view of FIG. 1 shows the connection-bumps 13 and 15 themselves, but not underlying features to which the connection-bumps 13 and 15 may be connected.
Connection-bumps 13 and 15 may be arranged around a periphery of a semiconductor device to facilitate device packaging. Consequently, VDD bumps 15 and GND bumps 13 are shown arranged around the periphery of semiconductor device 10 . Due to packaging restrictions, some semiconductor areas may be free from connection-bumps 13 and 15 . For example, to stabilize power operation of the semiconductor device, a packaged semiconductor device may have extra capacitors arranged on the package outside the die. Such arrangement may lead to connection-bump placement restrictions. Consequently, semiconductor device 10 is shown having an area without VDD bumps 15 and GND bumps 13 .
Semiconductor device 10 may include dense area 14 and sparse area 16 , where dense and sparse refer to density of connection bumps 13 and 15 . As will be discussed below in further detail, areas may be defined as dense or sparse using a variety of methods. However, in general within the same semiconductor device, a sparse area has at least one corresponding dense area. A dense area has connection bumps arranged at regularly spaced intervals along an axis. The regularly spaced intervals may be user-defined. A sparse area has connection bumps having at least some spaced intervals along the same axis which exceed the regularly spaced intervals of a corresponding dense area.
For example, the connection-bumps arranged closest to one another along at least one axis of a sparse area are further apart than the maximum distance between connection-bumps along either axis in a corresponding dense area. In particular, dense area 14 is defined, in part, by the connection bumps GND bump 101 and VDD bump 103 . Connection bumps GND bump 101 and VDD bump 103 are arranged along a y-axis and immediately adjacent one another. As shown, GND bump 106 and VDD bump 107 are also arranged along a y-axis and immediately adjacent one another, yet are spaced at a distance greater than that between GND bump 101 and VDD bump 103 . Consequently, GND bump 106 and VDD bump 107 define, in part, a sparse area.
As noted, connection-bumps 13 and 15 electrically couple semiconductor device 10 with its respective package. In this manner, packaged semiconductor device 10 may be in electrical communication with an electronic device. Thus, connection-bumps 13 and 15 provide electric potentials used by semiconductor device 10 . Within semiconductor device 10 , electric potentials may be routed through various conductors. Such conductors may be electrically coupled to connection-bumps 13 and 15 and may include contacts, vias, and interconnects.
Contacts and vias allow electrical coupling between layers of the semiconductor device. Thus, with respect to a wafer surface upon which semiconductor device 10 is fabricated, contacts and vias may have a substantially vertical orientation. Interconnects allow electrical coupling from one die area to another and may therefore have a substantially horizontal orientation. Interconnects may also be referred to as metal lines.
FIGS. 2-4 are diagrams illustrating respective embodiments of metal line configurations in accordance with the invention. Shown in FIGS. 2-4 is metal layer 20 . Metal layer 20 includes a magnified view of a portion of semiconductor device 10 approximated by exemplary area 18 of FIG. 1 . However, where FIG. 1 is a plan view of die 10 illustrating placement of GND bumps 13 and VDD bumps 15 , FIGS. 2-4 illustrate a plan view of metal layer 20 indicating placement of metal lines 11 and GND vias 113 . It is noted that a GND via 113 may be in a position within metal layer 20 which is substantially commensurate with a position of a corresponding GND bump 13 fabricated on a subsequent layer. Thus, FIGS. 2-4 illustrate at least some features which may be underlying and/or electrically coupled to the GND bumps 13 and/or the VDD bumps 15 illustrated in FIG. 1 .
The metal layer indicated in FIGS. 2-4 includes metal lines 11 . Metal lines 11 are functional metal lines. Functional metal lines are those lines used for the logical functioning of the semiconductor device. Logical functioning may include supplying power and transmitting signals. Thus, functional metal lines 11 may provide power to semiconductor device 10 . For example, logic gates may be electrically coupled to VDD by way of metal lines 11 . A logic gate may become operational upon application of a certain voltage level (e.g. VDD) provided by metal lines 11 . Semiconductor device 10 is designed such that metal lines 11 may deliver proper voltage levels to logic gates. However, increased impedance of metal lines 11 may cause increased voltage drops over metal line lengths. Proper operation of logic gates within semiconductor device 10 may therefore be dependent upon conductor impedance. Consequently, impedance of metal lines 11 may affect the logical functioning of semiconductor device 10 .
Impedance of metal lines 11 shown in FIGS. 2-4 may be adversely affected by the presence and/or operation of connection bumps including GND bumps 13 and VDD bumps 15 , shown in FIG. 1 . Referring to FIGS. 2-4 , consider exemplary functional metal line. 410 including a section labeled 199 and a section labeled 188 . Section 199 of metal line 401 traverses dense area 114 of metal layer 20 while section 188 of metal line 410 traverses sparse area 116 of metal layer 20 . The physical width and/or cross-sectional area of section 188 is substantially equivalent to the width and/or cross-sectional area of section 199 . Thus, it may be desired that the impedance of section 188 is substantially equivalent to the impedance of section 199 . However, the impedance of section 199 is not substantially equivalent to the impedance of section 188 due to respective connection bump densities in proximity to the respective sections without additional impedance-reducing conductor 488 . In particular, the impedance of section 199 traversing dense area 114 may be substantially less than the impedance of section 188 traversing sparse area 116 without additional impedance-reducing conductor 488 .
Various embodiments for reducing impedance variation are described in detail below. In general, impedance variation is ameliorated by adding impedance-reducing conductors to conductive layers. Impedance-reducing conductors may be added in attempt to normalize conductive-material density across the respective conductive layer. Alternately, impedance-reducing conductors may be added to normalize any one of a number of electro-magnetic properties. For example, impedance-reducing conductors may be added such that parasitic capacitance is constant across a metal process layer of a die. Consequently, impedance-reducing conductors may or may not be distributed periodically across sparse area 116 . For example, location 181 may not include an impedance-reducing conductor as impedance or other electro-magnetic properties may be normalized without adding impedance-reducing conductors to some locations.
FIG. 2 is a diagram illustrating one embodiment of a metal line configuration according to the invention. Impedance matching may be obtained by adding conductive material (e.g., metal) to a sparse area of metal layer 20 , where sparse area 116 is shown to have a lower density of GND vias 113 . Impedance-reducing metal lines 28 are added to the sparse area 116 of metal layer 20 to provide impedance matching. For example, impedance matched metal lines 11 may be attained by adding impedance-reducing metal lines 28 .
Impedance-reducing metal lines 28 may be added as necessary to achieve impedance matching. Therefore, the width of impedance-reducing metal lines 28 may not necessarily match the width of functional metal lines 11 .
Further, the width of impedance-reducing metal lines 28 may not be constant. Each impedance-reducing metal line 28 may have a different line width. Furthermore, a single impedance-reducing metal line 28 may have a varying line width. A single impedance-reducing metal line 28 may have a line width that varies deliberately from one section of the line to another.
Impedance-reducing metal lines 28 may be added to sparse area 116 of metal layer 20 and arranged in relationship with adjacent functional metal lines 11 such that regular spacing exists between the functional metal lines 11 and the impedance-reducing metal lines 28 . Impedance-reducing metal lines 28 are added to sparse area 116 of metal layer 20 , spaced more or less equidistant between flanking functional metal lines 11 . Thus, impedance-reducing metal lines 28 are added approximately halfway between functional metal lines 11 . Therefore, metal lines 28 may be referred to as having a ½ pitch arrangement with respect to functional metal lines 11 .
FIG. 3 is a diagram illustrating another embodiment of a metal line configuration according to the invention. Impedance-reducing metal lines 38 are added to the sparse area 116 of metal layer 20 to provide impedance matching. A distinction between impedance-reducing metal lines 38 and impedance-reducing metal lines 28 described above in reference to FIG. 2 is the spacing of the impedance-reducing metal lines 38 with respect to functional metal lines 11 .
The embodiment shown in FIG. 3 is similar to the embodiment shown in FIG. 2 with the exception of the arrangement of impedance-reducing metal lines 38 . Impedance-reducing metal lines 38 are added to sparse area 116 of metal layer 20 such that impedance-reducing metal lines 38 are not arranged substantially equidistant between adjacent metal lines 11 . As shown, impedance-reducing metal lines 38 are arranged approximately one fourth of the way between adjacent functional metal lines 11 . Therefore, metal lines 38 may be referred to as having a ¼ pitch arrangement with respect to functional metal lines 11 .
As described above, impedance matching conductive material may be added to semiconductor device 10 at any number of layers. Such conductive material may be added for conductive density matching and/or electro-magnetic matching across all conductive layers. The ¼ pitch placement of impedance-reducing metal lines 38 may facilitate placement of impedance-matching features on other conductive layers. For example, assume semiconductor device 10 includes impedance-reducing metal lines 28 and impedance-reducing metal lines 38 . In addition to these added impedance-reducing metal lines, another impedance-reducing metal line may be arranged at ¾ pitch. Such arrangement could result in three equally spaced impedance-reducing metal lines arranged laterally between functional metal lines 11 .
Because impedance-reducing features may be added to any or all conductive layers, added impedance-reducing features may not be limited to a single metal layer (i.e., a first metal layer may have impedance-reducing metal lines arranged at ¼ pitch, a second metal layer may have impedance-reducing metal lines arranged at ½ pitch, and a third metal layer may have impedance-reducing metal lines arranged at ¾ pitch.) Further, the functional metal line pitches of each layer may or may not be equivalent. Thus, impedance-reducing metal lines may be added at any metal layer having any desired pitch. Further, in addition to areas devoid of added conductive material such as area 181 , the pitch of added impedance-reducing metal lines may vary within a single process layer. Therefore, impedance-reducing metal lines need not be equally spaced.
FIG. 4 is a diagram illustrating yet another embodiment of a metal line configuration according to the invention. Again, impedance matching may be obtained by adding conductive material (e.g., metal) to a sparse area of metal layer 20 , where sparse area 116 is shown to have a lower density of GND vias 113 . Also, some similarities with respect to the embodiments shown in FIG. 2 and FIG. 3 may exist. However, this embodiment includes adding conductive material such that the effective line width of functional metal lines 11 is wider across sparse area 116 .
The metal layer shown in FIG. 4 includes metal lines 11 having supplemental metal line portions 48 . As shown, metal lines 11 and impedance-reducing metal line portions 48 are distinct lines in direct contact with one another, thus yielding an effective line width which varies over the length of metal line 11 . However, in practice, a metal line 11 may be fabricated having an integral section which is wider than other sections of line 11 .
As shown, metal line 410 is a functional metal line 401 arranged having a lateral edge substantially commensurate with a lateral edge of an impedance-reducing metal line portion 408 . The effective width of metal line 410 traversing sparse area 116 along the length labeled 482 is substantially wider than the remaining length of metal line 410 traversing dense area 114 . Due to the effects of connection bumps on impedance, the impedance of section 488 may be substantially equivalent to the impedance of section 499 due to the varying effective widths of the sections. However, as noted above, in practice metal line 410 may be fabricated as a single functional metal line 410 having a wider width along the section 482 . Regardless of fabrication method, the result is functional metal lines such as metal line 410 which have impedance in one section, such as section 499 , which substantially matches the impedance in another section traversing an area with a different connection bump density, such as section 488 .
FIGS. 5-8 are diagrams illustrating exemplary dense areas and exemplary sparse areas. Shown in FIGS. 5-8 are respective plan views of semiconductor device 10 having die edge 12 . The periphery of semiconductor device 10 is near die edge 12 and includes any dense areas. Connection-bumps including VDD bumps 15 and GND bumps 13 are arranged densely around the periphery of semiconductor device 10 . In semiconductor device 10 , connection-bumps VDD bumps 15 and GND bumps 13 are arranged sparsely near the center, where the center includes any sparse areas. Embodiments of methods to differentiate connection-bump density according to the invention will be described.
A dense area may be user-defined, and a sparse area may be defined as an area which has a density of connection bumps which is less than that of the defined dense area. A dense area may be determined by the spacing of connection-bumps such as GND bumps 13 and/or VDD bumps 15 . For example, a dense area may be defined by a quadrilateral of nearest adjacent GND bumps 13 along x and/or y axes.
Referring to FIG. 5 in particular, dense area 54 may be defined by GND bumps 504 , 505 , 502 , and 503 . To be considered a dense area in this embodiment, a distance between GND bumps along an x-axis may not substantially exceed the distance between GND bump 504 and GND bump 505 . Similarly, to be considered a dense area in this embodiment, a distance between GND bumps 13 along a y-axis may not substantially exceed the distance between GND bump 504 and GND bump 502 . As shown, the distance along the y-axis between adjacent GND bumps 506 and 508 of sparse area 56 significantly exceeds those of dense area 54 .
FIG. 6 is a diagram illustrating yet another method to differentiate connection-bump density according to the invention. An exemplary dense area 64 and an exemplary sparse area 66 are shown.
Dense area 64 is defined by a quadrilateral of nearest adjacent GND bumps 13 along x and y axes. In particular, dense area 64 is defined by GND bumps 604 , 605 , 602 , and 603 . Because the distances along x and y axes of GND bumps 606 , 607 , 608 , and 609 exceeds those of dense area 64 , area 66 is a sparse area. However, because dense area 64 is defined by distance between GND bumps along x and y axis, dense area 64 may also be defined by an area circumscribed by nearest adjacent GND bumps 13 along x and y axes.
FIG. 7 is a diagram illustrating yet another method to differentiate connection-bump density according to the invention. An exemplary dense area 74 and an exemplary sparse area 76 are shown. In contrast to dense areas 54 and 64 in FIGS. 5 and 6 , respectively, dense area 74 has laterally adjacent GND bumps 13 which are not necessarily separated from one another by VDD bumps 15 . As shown, GND bumps 704 and 705 are not separated from one another using a VDD bump 15 . In particular, dense area 74 may be defined by GND bumps 704 , 705 , 702 , and 703 . For an area to be considered a dense area, a distance between GND bumps along an x-axis may be equivalent to the distance between GND bump 704 and GND bump 705 . Similarly, a distance between GND bumps along a y-axis may be equivalent to the distance between GND bump 704 and GND bump 702 . As shown, along the y-axis the distance between adjacent GND bumps 706 and 708 exceeds that of dense area 74 along the y-axis. Therefore, area 76 defined by GND bumps 706 , 707 , 709 and 708 is a sparse area.
FIG. 8 is a diagram illustrating another method to differentiate connection-bump density according to the invention. An exemplary dense area 84 and an exemplary sparse area 86 are shown. In this embodiment, a dense area may be determined by a quadrilateral of nearest GND bumps 13 where the nearest GND bump can be either an absolute nearest GND bump or the nearest GND bump not arranged along either the x or y axis. For example, of interest may be the nearest GND bump arranged along xy or −xy diagonal axes.
In particular, dense area 84 may be defined by GND bumps 804 , 805 , 802 , and 803 . In this embodiment, an area may be considered a dense area if a distance between GND bumps arranged along a −xy diagonal does not exceed the distance between GND bumps 804 and 805 . Similarly, an area may be considered a dense area if a distance between GND bumps along an xy diagonal does not exceed the distance between GND bumps 804 and 802 . As shown, the distance between GND bumps arranged along xy diagonal 809 and 807 and those along −xy diagonal 808 and 809 of sparse area 86 exceeds those of dense area 84 . Also, the slope of the respective xy and −xy diagonals between the respective areas 84 and 86 are non-matching. Therefore, either distance or slope between nearest adjacent GND bumps 13 may be used to define an area as either sparse or dense.
Determination of dense and/or sparse areas may be made by examination of the distribution of connection-bumps. A dense area may be defined by distance between nearest adjacent GND bumps 13 along x and y axes, or by area circumscribed by nearest adjacent GND bumps 13 along x and y axes, or by distances between GND bumps along user-defined axis, or even by slopes of diagonal lines defined by nearest adjacent GND bumps. Hence, a dense area may be user-defined using any of a number of criteria.
Further, using user-defined criteria, connection-bump density may be determined through use of any one of a number of software packages. For example, a software package for determining semiconductor layouts may also be used to determine connection bump density. Consequently, determination of dense areas and/or sparse areas may be performed automatically using software to determine spacing between connection bumps GND 13 and/or VDD 15 . Such determination may be made from an algorithm including any combination of methodologies for determining dense areas presented above, among others. Further, dense or sparse may not necessarily be the only area designations. For example, relative or weighted area densities may be determined and/or compensated with impedance-reducing conductors. Furthermore, compensation conductor layouts may be similarly automated through use of such software packages.
In the foregoing specification, the invention has been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of invention.
Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any component(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component of any or all the claims.
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Systems and methods for improved semiconductor device performance are disclosed. In particular, presented are improved semiconductor systems and methods for configuring conductors to reduce impedance variation caused by proximity and/or density and/or operation of connection-bumps. The invention includes adding impedance-reducing conductive features which add no additional functionality to the semiconductor device. The added features may be arranged in areas of sparse connection-bump density. Impedance-reducing conductive features may include metal lines added between functional metal lines, where placement between adjacent functional lines may vary. Impedance-reducing conductive features may be added to any one or combination of conductive layers, and added features may act upon any one or combination of functional features. Further, added features may be electrically active and responsive to semiconductor device operation. Also, methods for determining connection-bump density, which methods may be automated.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a series of novel salt complexes that are made by neutralizing a fatty ammonium compound which is cationic with an anionic compound, producing a salt complex, and an inorganic salt. The compounds of the invention are water soluble, non-irritating to the eye and skin and are well suited to personal care applications.
2. Arts and Practices
Fatty quaternary compounds commonly called quats, are tetra-substituted ammonium compounds where each of the four groups on nitrogen are a group other than hydrogen. If any hydrogen groups are present, the compounds are not quaternary amines, but rather are primary or secondary amines.
The most commonly encountered substituents are alkyl and alkyl amido groups. There are several classes of quats. The most important are (a) alkyl tri methyl quats for example cetyltrimonium chloride, (b) alkylamidopropyl dimethyl quats like stearylamidalkonium chloride and (c) di alkyl, di methyl quats for example dicetyldimonium chloride and (d) alkyl, benzyl, Di methyl quats like stearalkonium chloride.
There are several undesirable attributes of fatty cationic products.
1. Fatty Quaternary compounds are incompatible with anionic surfactants since an insoluble complex frequently is formed when the two types of materials are combined.
2. Many fatty Quaternary Compounds are eye irritants. The material is minimally irritating to the eyes at concentrations of 2.5%, which limits the concentration which is useful if low irritation is a requirement.
3. Fatty quats are generally hydrophobic and when applied to substrate can cause a loss of absorbance of the substrate. It is not an uncommon situation for a traveler to a hotel to encounter a very soft towel that totally fails to absorb water. This is because the fatty quaternary gives softness but being hydrophobic also prevents re-wet. This situation also can be observed on hair, the conditioner becomes gunky on the hair and has a tendency to build up.
We have learned that many of these negative attributes can be unexpectantly mitigated by making fatty complexes with carboxy fatty alcohol alkoxylates. The preferred complex has to have a molecular weight of over 1000 molecular weight units to obtain the most effective irritation mitigation. The mitigation of irritation, the improved water solubility and the skin feel make the compounds of the present invention highly desirable in personal care applications.
THE INVENTION
OBJECT OF THE INVENTION
It is the object of the present invention to provide a series of novel salt complexes that are made by neutralizing a fatty ammonium compound which is cationic with an an anionic compound, producing a salt complex having a molecular weight above 1000 molecular weight units. The compounds of the invention are water soluble, non-irritating to the eye and skin and are well suited to personal care applications.
SUMMARY OF THE INVENTION
The invention relates to a series of novel salt complexes that are made by neutralizing a fatty ammonium compound which is cationic with an anionic compound, producing a salt complex having a molecular weight above 1000 molecular weight units. The compounds of the invention are water soluble, non-irritating to the eye and skin and are well suited to personal care applications.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of the present invention conform to the following structure:
wherein;
R 1 is CH 3 —(CH 2 ) n —O—(CH 2 CH 2 O) a —(CH 2 CH(CH 3 )O) b —(CH 2 CH 2 O) c —;
n is an integers ranging from 7 to 21;
a and c are integers independently ranging from 0 to 20,
with the proviso that a+b be greater than 5;
b is an integer ranging from 0 to 20;
R 2 is selected from the group consisting of —CH 2 —CH 2 —, —CH═CH—, and
R 3 is selected from the group consisting of
CH 3 (CH 2 ) e —
and
R 5 —C(O)N(H)—(CH 2 ) 3 —
R 5 is CH 3 (CH 2 ) f —
e is an integer from 5 to 21;
f is an integer from 5 to 21;
R 4 is selected from the group consisting of
CH 3 (CH 2 ) g
g is an integer ranging from 0 to 21 and
PREFERRED EMBODIMENTS
In a preferred embodiment R 1 is;
CH 3 —(CH 2 ) n —O—(CH 2 CH 2 O) a —(CH 2 CH(CH 3 )O) b —(CH 2 CH 2 O) c —.
In a preferred embodiment R 2 is —CH 2 —CH 2 —.
In a preferred embodiment R 2 is —CH═CH—.
In a preferred embodiment R 2 is
In a preferred embodiment e is an integer ranging from 7 to 21.
In a preferred embodiment R 3 is;
R 5 C(O)N(H)—(CH2)3—
f is an integer ranging from 5 to 21.
In a preferred embodiment R 4 is methyl.
In a preferred embodiment R 4 is
In a preferered embodiment the molecular weight of the complex is greater than 1000.
In another preferred embodiment, the complex is blended with dimethicone copolyol to improve the skin feel.
EXAMPLES OF REACTANTS
ANHYDRIDES
The various anhydrides listed are all items of commerce and are prepared by methods known to those skilled in the art.
The reaction sequence is illustrated by the reaction with succinic anhydride:
Raw Materials
Alkoxylated alcohols suitable for the preparation of the compounds of the present invention are commercially available from Siltech Corporation in Toronto Ontario Canada.
R 1 —C(O)—R 2 —C(O)OH
Example
n
a
b
c
1
8
0
0
5
2
10
0
1
12
3
12
20
10
20
4
14
3
1
3
5
16
20
20
20
6
18
12
0
0
7
20
12
1
1
8
22
5
0
5
General Reaction Conditions
Into a suitable round bottom, three neck flask equipped with a thermometer and a nitrogen sparge is added the specified number of grams of the specified alcohol alkoxylate compound and the specified number of grams of the specified anhydride. The reaction mass is blanketed with nitrogen, and heated to 80 and 110° C. under the inert nitrogen blanket. Within four to five hours the theoretical acid value is obtained. The product is a clear liquid and is used without additional purification.
EXAMPLES 9-14
Succinic Derivatives
Into a suitable round bottom, three neck flask equipped with a thermometer and a nitrogen sparge is added the specified number of grams of the specified alcohol alkoxylate (examples 1-8) compound and the 100.0 grams of succinic anhydride. The reaction mass is blanketed with nitrogen, and heated to 80° and 110° C. under the inert nitrogen blanket. Within four to five hours the theoretical acid value is obtained. The product is a clear liquid and is used without additional purification.
Alcohol
Alkoxylate
Example
Example
Grams
9
1
391.0
10
2
742.0
11
3
2533.0
12
4
447.0
13
5
3179.0
14
6
795.0
15
7
926.0
16
8
763.0
EXAMPLES 17-24
Maleic Derivatives
Into a suitable round bottom, three neck flask equipped with a thermometer and a nitrogen sparge is added the specified number of grams of the specified alcohol alkoxylate (examples 1-8) compound and the 98.0 grams of maleic anhydride. The reaction mass is blanketed with nitrogen, and heated to 80° and 110° C. under the inert nitrogen blanket. Within four to five hours the theoretical acid value is obtained. The product is a clear liquid and is used without additional purification.
Alcohol
Alkoxylate
Example
Example
Grams
17
1
391.0
18
2
742.0
19
3
2533.0
20
4
447.0
21
5
3179.0
22
6
795.0
23
7
926.0
24
8
763.0
EXAMPLES 25-32
Phthalic Derivatives
Into a suitable round bottom, three neck flask equipped with a thermometer and a nitrogen sparge is added the specified number of grams of the specified alcohol alkoxylate (examples 1-8) compound and the 146.0 grams of phthalic anhydride. The reaction mass is blanketed with nitrogen, and heated to 80° and 110° C. under the inert nitrogen blanket. Within four to five hours the theoretical acid value is obtained. The product is a clear liquid and is used without additional purification.
Alcohol
Alkoxylate
Example
Example
Grams
25
1
391.0
26
2
742.0
27
3
2533.0
28
4
447.0
29
5
3179.0
30
6
795.0
31
7
926.0
32
8
763.0
CATIONIC EXAMPLES
The cationic compounds of the present invention are commercially available from a variety of sources including Croda Inc. and Siltech Corporation.
They conform to the following structure:
wherein;
R 3 is selected from the group consisting of
CH 3 (CH 2 ) e —
and
R 5 —C(O)N(H)—(CH 2 ) 3 —
R 5 is CH 3 (CH 2 ) f —
e is an integer from 5 to 21;
f is an integer from 5 to 21;
R 4 is selected from the group consisting of
CH 3 (CH 2 ) g
g is an integer ranging from 0 to 21 and
M is selected from the group consisting of Cl − , Br − , and CH 3 SO 4 —.
As used herein
is referred to as benzyl.
Class 1 Cationic Compounds
e
g
33
7
0
34
11
0
35
17
0
36
17
0
37
21
0
38
21
benzyl
M is Cl −
Class 2 Cationic Compounds
e
g
39
7
7
40
11
7
41
15
21
42
17
3
43
21
5
44
17
benzyl
45
21
benzyl
M is Cl −
Class 3 Cationic Compounds
R3 is R 5 C(O)N(H)—(CH2)3—
Example
f
g
46
7
0
47
9
0
48
11
0
59
17
11
50
21
21
51
17
Benzyl
52
5
11
M is Cl −
Complexation
The carboxy fatty alcohol alkoxylate (examples 9-32) and the cationic compound (examples 33-52) are blended into water to make up a concentration of between 20-70%. The preferred range is 30-50% by weight. The pH of the resulting mixture is then adjusted to between 5 and 9. The lower pH is preferred for skin care products, the higher for hair care products. The complex forms in aqueous solution and the counter ion on the cationic material remains in the solution as inorganic salt.
EXAMPLE 53
To a suitable vessel is added 840.0 grams of water. Next 491.0 grams of anionic compound Example 9 is added under agitation. Next 209.0 grams of cationic compound 33 is added. The pH is adjusted to 7.0 with KOH. The complex is used as prepared.
EXAMPLES 54-76
Example 53 is repeated, only this time the specified amount of water. Next the specified amount of the specified anionic compound is added. Next the specified amount of the specified cationic compound is added. The pH is adjusted to 7.0 with KOH. The complex is used as prepared.
Anionic
Compound
Cationic
Compound
Water
Example
Example
Grams
Example
Grams
Grams
54
10
842.0
34
265.0
1328.0
55
11
2633.0
35
349.0
3578.0
56
12
547.0
36
373.0
1104.0
57
13
3279.0
37
405.0
4420.0
58
14
895.0
38
416.0
1704.0
56
15
1026.0
39
293.0
1582.0
60
16
863.0
40
349.0
1515.0
61
17
489.0
41
601.0
1635.0
62
18
840.0
42
377.0
1292.0
63
19
2631.0
43
416.0
3656.0
64
20
545.0
44
389.0
1167.0
65
21
3277.0
45
445.0
4466.0
66
22
893.0
46
280.0
1257.0
67
23
1024.0
47
308.0
1600.0
68
24
861.0
48
336.0
1436.0
69
25
537.0
49
574.0
1333.0
70
26
888.0
50
770.0
1812.0
71
27
2679.0
51
511.0
3992.0
72
28
593.0
52
406.0
1250.0
73
29
3325.0
51
511.0
5754.0
74
30
941.0
50
770.0
2053.0
75
31
1072.0
49
574.0
1646.0
76
32
909.0
45
445.0
1760.0
Applications Evaluation
Control Compounds
Stearalkonium Chloride is an excellent conditioning agent, having outstanding substantivity to hair. It has detangling properties, improves wet comb when applied after shampooing. The FDA formulation data f or 1976 reports the use of this material in 78 hair conditioners, eight at less than 0.1%, eighteen at between 0.1 and 1.0% and 52 at between 1 and 5%.
Cetyltrimonium Chloride, or CTAC, is a very substantive conditioner which in addition having a non-greasy feel, improves wet comb and also provides a gloss to the hair. It is classified as a severe primary eye irritant. 18 Therefore its use concentration is generally at or below 1%.
Eye Irritation
Eye irritation is a major concern in the formulation of personal care products, particularly when working with quats. Primary eye irritation was tested using the protocol outlined in FHSLA 16 CFR 1500.42. The products were tested at 25% actives. The results were as follows:
Cationic Compounds (Not of the Present Invention)
Stearalkonium Chloride
116.5
Severely Irritating
Cetyltrimethyl
106.0
Severely Irritating
ammonium Chloride
Cetyltriethyl
115.0
Severely irritating
ammonium Chloride
Complexes of the Present Invention
Example 56
8.1
Minimally Irritating
Example 61
11.3
Minimally Irritating
Example 62
10.2
Minimally Irritating
Example 70
4.9
Minimally Irritating
Example 76
7.8
Minimally Irritating
As the data clearly shows, the irritation potential of the complex is dramatically reduced, when compared to the starting quat.
|
The invention relates to a series of novel salt complexes that are made by neutralizing a fatty ammonium compound which is cationic with an anionic compound, producing a salt complex. The compounds of the present invention are water soluble, non-irritating to the eye and skin and are well suited to personal care applications.
| 2
|
This is a division of application Ser. No. 523,051 filed Nov. 12, 1974, now abandoned.
SUMMARY OF THE INVENTION
The present invention is directed to apparatus for blade coating a liquid on a moving web and, more particularly, it is directed to the passage of the web through a closed chamber where the blades define the entrance and exit for the strip into and out of the closed chamber.
A moving web or strip of material can be coated with liquid in various ways and by different apparatus depending on the quantity and uniformity of the coating desired and the properties of the web or of the coating liquid. Accordingly, it is feasible to use coating blades or brush rollers, air brushes, presses and the like. The apparatus used is generally open for affording easy accessability for cleaning the apparatus or for rearranging the apparatus after a web rupture, however, under such conditions the liquid can easily spread to parts of the apparatus where it is not wanted and it is easily polluted. Occasionally closed systems are used under pressure so that viscous liquids can be pressed against the web, but even such a coating method leads to spreading of the liquid and to other drawbacks. Blade coating, which is probably the most economical method and which is used for paper when high quality and capacity are required, is substantially limited to coating with mixtures having high viscosity, often demanding great accuracy as to consistency and concentration. In such coating operations it is important that the shape of the blade, its stiffness and its contact with the web are carefully adjusted to the existing conditions, and such adjustment is often difficult to maintain. It is particularly important that a uniform contact is provided over the entire width of the web. Uneven coating across the width of the web or scratching are easily caused, for example, by uneven stiffness of the blade, uneven load-application on the blade, by a thickening of the mixture, or by the presence of impurities.
Accordingly, the primary object of the present invention is to provide apparatus for extending the field of blade coating and to reduce the drawbacks experienced in the past. In the coating operation, the liquid is permitted to flow against or contact the web between two laterally positioned end pieces and between two blades extending transversely of the end pieces and which are freely movable against the end pieces, with one of the blades providing a wiping-on action and the other a wiping-off action. The advantages gained in using the present invention have been surprisingly great, as will be noted from the examples set forth in the following description.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a coating apparatus embodying the present invention;
FIG. 2 is a schematic view, similar to FIG. 1, showing a coating apparatus illustrating another embodiment of the present invention;
FIG. 3 is another schematic view, similar to FIGS. 1 and 2, displaying a coating apparatus with yet another embodiment of the present invention; and
FIG. 4 is another schematic view, similar to FIGS. 1-3, displaying a coating apparatus with yet another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In the drawing four different embodiments are shown in which a paper web is introduced into a closed chamber where it is coated with a liquid as it passes between two spaced blades one located at the entrace to the closed chamber and the other located at the exit. Similar parts in the four embodiments are designated with the same reference numerals. Further, four examples are provided based on laboratory experiments carried out using the apparatus illustrated in FIG. 1.
In FIG. 1, as indicated by the arrows, a paper web 1 passes over a roller 2 having a polished surface and for a portion of its passage over the roller the web moves upwardly through a body 42 of coating liquid. After the web passes above the liquid level 12 any excess liquid on the web is wiped off. In forming the receptacle for the coating liquid, a box 3 is positioned adjacent the circumferential periphery of the roller and a pair of spaced blades 4-5 and 6-7 are mounted within the box so that the front edges 4,6 of the blades contact the web. The lateral surfaces or sides of the box 3 have fixed end pieces forming edge 3 1 facing toward but spaced from the circumferential periphery of the roller 2. The attachment points 5, 7 of the blades 4-5, 6-7 are located on the fixed edge 3 1 . In addition the sides of the box include movable, lockable, flat, sealing end pieces 8 against which the side edges of the blades can move freely. The sealing end pieces have circular sections extending between the spaced points 9, 10 which contact the paper web 1 passing over the roller and the circular sections 9-10 are sealed by a strip of rubber at the contact surface with the paper web. As a result, the box 3 in combination with the circumferential periphery of the roller 2 forms a closed chamber into which the coating liquid is charged. The box 3 forms an opening to the closed chamber defined by the front edges 4, 6 of the blades 4-5, 6-7 and the edges 9-10 of the movable end or side pieces of the box. This opening is closed by the circumferential periphery of the roller 2 which provides a support member for the paper web 1 which moves across the opening between the blades.
The coating liquid is pumped into the lower part 11 of the closed chamber to a level 12. The height of the level is adjusted by a spillway 13 which is movable at joint 14. The joint 14 is shown by way of example, since the height of the spillway 13 can be adjusted in a number of other ways which are well known. As the coating liquid rises to the top of the spillway 13 it flows downwardly to the right of the spillway as viewed in FIG. 1, where it forms a level 17. The liquid is stored in a reservoir 15 and flows into the closed chamber between the spillway 13 and the roller 2 and returns to the reservoir from the space within the box having the level 17. The level 16 within the reservoir 15 is at ambient pressure. However, the pressure within the closed chamber at the liquid levels 12 and 17 is regulated by a suitable balance between the vacuum line 18 and the pressure line 19.
To regulate the angle of the blade 6-7 which provides a wiping off action, the blade attachment point 7 is secured to a part 20 having the shape of a circular arc which is movably supported on a base 21 attached to the box 3 which has a complementary circular arcuate shape. Although not shown, the box is fixed to a stand so that its position in contact with the web can be adjusted, that is, so that the box can be moved toward or away from the web. The stand and the box afford a stable arrangement so that the vacuum developed within the closed chamber in the box does not affect its position.
In carrying out the coating operation, the blade 6-7 acts as a wiping-off blade. The positions and pressure acting on the blades can be roughly set by moving the box 3 toward or away from the web/roller while it slides between the loosened end or side pieces 8. Otherwise, the blades will function and be regulated differently.
The blade 4-5 smooths, evens out and compresses the web. This blade should also balance the pressure from the liquid and the vacuum. However, no work is performed on the liquid. As a result, the torque on the blade 4-5 developed at attachment point 5 would be reasonable. Furthermore, the torque can be easily adjusted uniformly across the width of the web and, as shown in FIG. 1, a channel 5 1 is provided containing a tube 43 in which the pressure is regulated for exerting a uniform torque on the blade. The channel with the tube could also be located at point 5.
The wiping-off blade 6-7 smooths the coating while wiping off any excess liquid at a location spaced above the liquid level 12 in the closed chamber. In the performance of its task on the coating liquid, the blade may create some resistance at high speeds of the web and high viscosity of the liquid. The necessary high pressure at the front edge 38 of the blade is, in this case, attained by the adjustment of the vacuum conditions within the closed chamber. The blade must of course be stiff enough so that the vacuum conditions within the closed chamber is converted to pressure at the front edge 38 of the blade so that the angle at that location would be suitable. However, no torque is provided at attachment point 7 to effect the contact of the blade 6-7 at its front edge 38. As a result, the blade may be relatively thin and flexible and the considerable forces are applied only by the vacuum conditions within the chamber which can be adjusted with great accuracy and can be automatically distributed uniformly across the width of the web.
At the commencement of the coating process, the box 3 is roughly fitted against the web 1/ roller 2. A vacuum pump 37 is connected to the vacuum line 18. A pump 22 is positioned in the supply line 40 extending between the reservoir 15 and the lower part 11 of the closed chamber for charging the coating liquid into the box and the rate at which the liquid is supplied is regulated by a valve 23 in the line 40. As mentioned above, the liquid level 12 within the closed chamber is regulated by the position of the upper end of the spillway 13. The pressure at the front edge 44 of the blade 4-5 is adjusted by means of the hydraulic pressure in the tube 43 located in the channel 5 1 . At the front edge 38 of the wiping-off blade 6-7, the pressure is regulated by the valved vacuum line 18 and the similarly valved supply line 19 which is regulated to reduce the vacuum, as required. The angle of the wiping-off blade relative to the paper web 1 at its front edge 38 is accurately adjusted by moving its attachment point 7 secured to the movable part 20. During the rough adjustment of the box described above, it is normally positioned so that the front edge 38 of the wiping-off blade just reaches the web. Therefore, the position of the front edge 38 remains unchanged even if the angle of the blade to the paper web is altered by moving the attachment point 7. If the apparatus depicted is run at a high vacuum and the blade is so thin that it becomes bent, the rough adjustment can be readjusted taking into consideration the shorter distance between the front edge 38 and the attachment point 7. However, during normal operating conditions using blades of normal stiffness, this readjustment is unnecessary.
When coating is to be discontinued, the pump 22 and the vacuum pump 37 are switched off and the box can be emptied of liquid. Further, if desired, the box can be pulled away from the circumferential surface of the roller. The procedure is the same if a breakage occurs in the web after the coating has been completed. The same procedure can be carried out if the web breaks before reaching the coating apparatus, however, in such a case the pumps should preferably be stopped automatically. The box is suitably cleaned with the help of a permanently fitted spray damper. Necessary cleaning can often be performed without pulling the box away from the roller, that is, it can be performed virtually without any interruption in operation.
In FIG. 2 the positions of the blades have been reversed so that the web contacts the blade 4-5 approximately at the liquid level 12, and moves downwardly in contact with the liquid until it reaches the wiping-off blade 6-7 at the point at which it exits from the closed chamber within the box. This particular arrangement is desirable, if the coating liquid is sensitive to air. The box can be located in several positions around the periphery of the roller and in FIG. 2 it is shown with the box extending downwardly below the lowermost part of the roller. In this arrangement the wiping-off blade 6-7 is maintained completely below the level 12 of the liquid. Further, by the suitable positioning of the spillway 13 the level 12 can be generally maintained above the edge 44 of the wiping-on blade 4-5. Otherwise for starting, stopping and any breakdowns in the apparatus, it will function in the manner described with respect to FIG. 1. In FIG. 3 another embodiment of the invention is shown with some significant differences in the arrangement for the supplying of the coating liquid in the closed chamber and for the contact of the wiping-off blade with the web.
A strip of material or web 1 moving in the direction of the arrows passes over a solid support or roller 2 so that the portion of the roller over which the web passes is located in the range of an open side of the box 3. At the commencement of the coating operation the web 1 passes between the roller 2 and the contact point 44 of the blade 4-5 and at the end of the coating operation the web passes between the front edge 38 of the wiping-off blade 6-7 and a slip plate 2 1 . The end pieces 8 movably positionable on the sides of the box, are sealed to the box with the blades arranged in the same manner as described with respect to FIG. 1. Accordingly, the end pieces 8 contact the web or the surface of the roller 2 and the slip plate 2 1 . The arrangement of the end pieces 8, the blades 4-5, 6-7, and the roller 2 and slip plate 2 1 provide a closed chamber through which the web 1 passes during the coating operation. Within the closed chamber a pocket 11 is provided in which the coating liquid is maintained at a level 12. The coating liquid is supplied from a source or reservoir 15 having its liquid level 16 at atmospheric pressure and the liquid returns to the reservoir from the supply which has a liquid level 17 within the box. The closed chamber within the box is maintained at vacuum conditions corresponding to the levels 17, 16 by means of the valved vacuum line 18. The partial vacuum within the closed chamber is accurately adjusted by the valved pressure line 19. As shown in FIG. 1, the wiping-off blade 6-7 is attached to a support part 20 having the configuration of a circular arc and the part is mounted on a base 21 having a complementary configuration. The liquid is supplied from the reservoir 15 by a pump 22 through a supply line with the flow being regulated by the valve 23.
As distinguished from the apparatus shown in FIGS. 1 and 2 where the coating liquid flows into the lower part 11 of the closed chamber, in FIG. 3 the supply line from the reservoir 15 is connected to a pivotally mounted spreader pipe 24 which forms one side of the space in the closed chamber within which the coating liquid is maintained in contact with the web passing over the roller 2. The pipe 24 has a pair of flanges 25, 26, with the flange 25 directed downwardly and the flange 26 directed upwardly so that its edge spaced outwardly from the pipe forms the top of the spillway defining the level 12 over which the liquid flows into the space having the liquid level 17. By pivoting the pipe 24 its lower flange 25 can be seated in sealing relation with a shaped part 27 in the bottom of the box 3 so that the body of liquid is retained in the lower part or space 11 where it extends upwardly to the level 12 defined by the upper edge of the flange 26. Holes or slots 45 are provided in the spreader pipe opening into the lower part 11 when the flange 25 is in the generally vertical and sealing position. If the spreader pipe is pivoted from the sealing position of the flange 25 with the part 27 of the box, the pocket will be emptied, and if the supply to the valve 23 is cut off and the partial vacuum reduced, the box can be completely emptied. With the valve 28 in the discharge line from the box 3 to the reservoir 15 closed and the valve 29 in the branch line from the discharge line opened, the inside of the box can be washed. This can be done by opening valve 30 in another branch line connected to the supply line at a point downstream from the valve 23 for supplying the cleaning liquid to the spreader pipe 24 which can be turned manually or by a motor with programmed movement. During the washing operation, the mixture can be permitted to circulate outside the box 3 through the pump 22 and a pressure-regulated valve 31 located in a line extending between the supply line and the discharge line. After washing, the coating operation is commenced by closing the cleaning liquid valves 30, 29, opening the coating liquid valves 28, 23 and moving or pivoting the spreader pipe 24 to the sealing position of its flange 25 with the part 27 of the box.
If the smoothing and pressing blade were positioned with its front edge extending in the direction of travel of the web 1 it would have to be pressed by special means against the web and it would be difficult to avoid pockets developing which are difficult to clean. What might be even worse would be the possibility of thickened patches of the coating liquid forming along the front edge of the blade, which could easily occur. Such patches would hang like curtains over the web and prevent the supply of the coating liquid, or they would fall off. The disturbance caused by such an occurrence can be reduced by inserting the blade so that its front edge 46 faces in the direction opposite to the direction of travel of the web so that the thicknesses in the coating liquid are fed in on the blade, that is, down in the bottom of the trough, from where they can be easily removed in a suitable manner if necessary. The partial vacuum developed within the closed chamber forces the blade against the web with a pressure which is roughly determined by the distance between the contact point 44 of the blade and its attachment point 5" on the box. Admittedly, it is somewhat more difficult with the oppositely directed blade to obtain a steep drop between the contact point 44 and the attachment point 5" and a small volume for the space 11 containing the liquid. However, this disadvantage is slight if the solid support 2 is formed by the combination of a rotating roller 2 having a small radius and a slip plate 2 1 located with one edge adjacent the roller and its other edge spaced upwardly above the roller. As can be seen in FIG. 3, the slip plate 2 1 extends generally tangentially and upwardly from the roller 2. To prevent the web 1 from being pressed into the box at the point between the roller and the slip plate, the joint may be screened off by a sealing sheet 32 with the space defined between the sealing sheet, the roller and the slip plate connected to a valved vacuum line 33 so that adequate vacuum conditions are maintained.
When the coating paper has irregularities, such as bark particles, it has been found advantageous to use a fixed slip plate having a trough across the web below the front edge 6 of the wiping-off blade 6-7. The web is passed stretched over the trough, into which irregularities are pressed, so that the other side of the web is flat as it passes between the front edge 6 and the slip plate. As distinguished from the arrangements shown in FIGS. 1 and 2, the wiping-off blade 6-7 does not bear against the web where it is supported by the roller 2, rather it contacts the web at a position spaced outwardly from the roller as the web passes over the slip plate 2 1 . The separation of the solid support for the web into a rotating roller and a stationary slip plate, as shown in FIG. 3, is one of other suitable modifications of the present invention.
The apparatus disclosed in FIG. 4 is particularly useful when the coating liquid has a high viscosity. The apparatus differs from that of FIGS. 1-3 in that the coating liquid does not form a pool in contact with the web. The coating fluid is sprayed from the spray tube 24 as film 47 against the web 1. The film 47 accompanies the web 1 up to the point 38 where the blade 6 contacts the web 1. Here excess liquid is wiped off and flows back to the lower portion 11 of the box 3. If the web ruptures the spray tube 24 is preferably rotated so that the film 47 is sprayed directly back to the bottom portion 11 of the box 3. By continuing the circulation of the viscous liquid during periods of web rupture it is possible to avoid changes in viscosity of the liquid. Stagnant liquid usually experiences a change in viscosity.
Test coating has been formed with the apparatus illustrated in FIG. 1. During the testing as described in the examples below, the blade 4-5 was positioned at an angle of 40° to the paper web and the dimension of the blade between its front edge 44 and attachment point 5 was 30 mm and its thickness 0.35 mm, while the comparable dimensions of the wiping-off blade 6 were 85 mm and 0.35 mm, respectively. The curvature of the blades was negligible for a vacuum of up to 1200 mm (the vacuum is defined here and in the following Examples as the height of a column of water, in millimeters). Comparison coating tests were also performed in a conventional manner. Example 1 shows the results of the variables essential to the invention using pigment coating, performed with a mixture of ordinary composition. In Example 2 the results are compared with a mixture having a high concentration of pigment coated in accordance with the present invention and then in a conventional manner using trailer blades. In Example 3 CMC has been used while in Example 4 a release chemical was employed both having been applied in accordance with the present invention and with a size press.
EXAMPLE 1
Pigment coating using an ordinary coating mixture
A web of paper of the quality MG sulphate was coated with a coating liquid consisting of an aqueous dispersion of 58 percent by weight kaolin, 6.7 percent by weight styrene-butadiene latex, 0.9 percent by weight CMC as thickener, and 0.1 percent by weight dispersing agent.
1.1 Quantity of coating dependent on web speed and angle of contact of the wiper blade (measured at no-load). Viscosity of mixture, 1800 cP, vacuum, 600 mm.
______________________________________Angle 15° 20° 25° 30° 50°Speedm/min Quantity of coating 50 23 13 5 4 3100 6 3 3150 11 3 2200 17 4 3250 4 2300 5 3350 7 3______________________________________
The coating increases with increased web speed and/or reduced blade angle. With a small blade angle the quantity will be stable and reasonably low only if the speed is kept low. With blade angles above 25° the coating becomes gradually lower and independent of the speed.
1.2 Quantity of coating dependent on vacuum and angle of contact of wiper blade. Viscosity of mixture, 1800 cP, web speed 50 m/min.
______________________________________Angle 15° 25°Vacuum Coating quantitymm g/m.sup.2 g/m.sup.2100 8.3200 7.6300 6.4400 5.9500 5.2600 23.4 5.0800 18.4 5.0 1000 17.0 1200 15.5______________________________________
1.3 Quantity of coating dependent on vacuum and viscosity of mixture. Angle of contact of wiper blade, 15°, web speed, 50 m/min.
______________________________________Viscosity 1200 cP 1800 cP 2500 cPBrookfieldVacuum Coating quantitymm g/m.sup.2 g/m.sup.2 g/m.sup.2600 20 23 29800 16 18 19______________________________________
Tables 1.2 and 1.3 show, inter alia, that a high coating quantity obtained with a small angle of contact, can to a certain extent be kept constant even with varying web speed (see 1.1) and/or varying viscosity. This can be done by program-regulating the vacuum. This, together with a simple adjustment of the angle of contact of the wiper blade, and the greatly improved chances of using even small blade angles are the characteristic features of the invention.
EXAMPLE 2
Pigment coating using a high pigment concentration
A paper web was coated with a pigment mixture consisting of an aqueous dispersion of 68 percent by weight kaolin, 9 percent by weight styrene-butadiene latex, and 0.1 percent by weight dispersing agent. The coating was made in accordance with the invention. Comparative tests were made with the conventional coating method using a trailer blade, i.e. a single blade 100 mm long and 0.35 mm in thickness, the mixture being applied by roller. Web speed 50 m/min. Blade angles, for the invention 20° and for the trailer blade coating 40°.
The removal of CMC enables a higher pigment concentration to be used as well as an increased quantity of coating, but results in poorer stability of the mixture.
__________________________________________________________________________Invention ConventionalTime Conc. Visc. Quantity Surface Uniformity.sup.x Conc. Visc. Quantity Surface Uniformitymin % cP g/m.sup.2 cm.sup.3 /min % cP g/m.sup.2 cm.sup.3 /min__________________________________________________________________________0 68.3 2800 68.3 28001 68.3 2800 46 9 68.3 2800 19 265 68.3 2800 1910 68.2 2800 47 68.4 2800 1915 68.4 2850 1920 68.3 2800 50 68.5 2950 2025 68.5 2950 2130 68.3 2800 50 8 68.6 3100 23 1940 68.3 2800 50 7 68.6 3150 2550 68.8 3200 26 72__________________________________________________________________________ .sup.x measured according to Bendtsen.
The table shows that the invention permits copious and uniform coating without the liquid becoming thicker. With the conventional method it was necessary to work with lower coating levels and an acceptable result was then obtained. However, this could not be maintained upon continued operation, which resulted in a thickening of the mixture, increased coating and quite unacceptable scratches.
Another experiment performed in accordance with the invention with the concentration and viscosity the same as in the above experiment but adjusted for a less generous quantity of coating, resulted in a uniform coating of 15-16 g/m 2 . After 60 minutes in operation no alterations had occurred. The surface uniformity was in this case measured at values between 8-11 cm 3 /min.
EXAMPLE 3
Coating with CMC
A dense surface is aimed at here with the highest possible CMC concentration. Comparison with conventional coating in size press using two different CMC concentrations. Paper quality: greaseproof-sulphite.
______________________________________ Invention Conventional 1 side 1 side 2 sides______________________________________2.5 % CMCPinholes per m.sup.2 600 1900 600Porosity sec 2.5 2.0 3.01.25 % CMCPinholes per m.sup.2 500 2200 600Porosity sec 2.0 2.4 6.0______________________________________
The invention results is an approximately equally high quality after coating only one side of the paper as is achieved after coating both sides of the paper in the conventional manner.
EXAMPLE 4
Coating with release chemicals
Here the aim is to obtain a uniform coating concentrated at the surface of the paper. The following results were obtained using a silicon emulsion first in accordance with the invention and then using a conventional size press. The silicon emulsion was made by Rhone-Poulenc, and was used in concentrations of 4, 6 and 8 percent by weight of solids.
The results were measured according to Tappi RC-283. A strip of adhesive tape is pressed against the treated paper for 20 hours at 70° C. and about 200 mN/cm 2 . When the sample has cooled the delamination force is measured and the average value (a) of 5 measurements is noted. The tape strip drawn off is then pressed against a stainless steel plate by a weight of 1 kg which is rolled slowly over it twice. The delamination force (b) is measured as above.
______________________________________ Delamination force Quantity coated a b g/m.sup.2 pond pond b/a______________________________________The invention 0.42 10 220 22 0.58 10 240 24 0.64 10 210 21Conventional 0.35 60 110 1.8 0.50 45 150 3.3 0.65 35 170 4.8______________________________________
Irrespective the quantity of coating, it is considerably easier (a) to pull the tape off the paper which has been treated in accordance with the invention. Less glue is also removed from the adhesive tape strip and this is consequently more difficult (b) to pull from the stainless steel plate. The release effect is infinitely better when the new method is used.
By maintaining the coating liquid within a closed chamber, the present invention aims to reduce the pollution of the coating liquid from the surroundings and also the pollution of the surroundings by the coating liquid. The results and experience gained from the test runs show that it is possible, using the present invention, to obtain the reduction in the pollution mentioned above. Furthermore, the expected improvement is quality has been surprisingly greater, as shown by the examples. Coating with totally different liquids for different purposes has resulted in coatings of superior quality even with small quantities of coating and in surfaces of superior smoothness even when large quantities of coating are applied and when liquid having high consistencies and/or high pigment concentration are used. The possibilities of regulating the coating quantities and keeping them constant have been radically improved.
The reason for these unexpectedly good results has not been fully determined, however, it is obvious that for most purposes it is desirable to use small quantities of coating, concentrated at the surface of the paper. The coating procedure permits highly viscous liquids to be pressed very close to the desired point near the coating blade. The liquids can run down to the blade due to the relatively great differences in level inside the box, without being disturbed by the pressure from the liquid pump. This, together with the smoothing and compressing action on the web, in combination with the vacuum conditions maintained, probably insures that the coating is satisfactorily placed in contact with the surface of the paper and, at the same time, the solvent is prevented from penetrating into the paper in an unsuitable or, in certain cases, even a damaging manner. Since the wiping-off action can be carried out with a relatively small blade angle, satisfactory regulation and little disturbance from the surroundings, the total result is so good that it can be designated as synergetic.
Another valuable feature of the present invention is the sharp lateral limitation of the coating effected on the web or strip of material. This feature enables the web to be coated in several strips, well defined from one another, with the separate strips being applied by using separate boxes or a single box divided by partitions with separate blades extending between the partitions.
The method can be employed for melts or other coating liquids and webs than those mentioned in the examples. The apparatus and its use relative to the web can also be modified, for example, by placing the web against a non-curved surface or a soft surface, using different blade lengths, thickness and angle of contact, producing contact by means of gas pressure from the outside instead of vacuum from the inside, or regulating the level of the liquid in some way other than by overflow and return of the liquid. It is also possible to regulate the contact of the blade by maintaining an overpressure inside the box and at the same time regulating the contact of the wiper blade by maintaining an even higher pressure on the outside. The web can also be coated on both sides by placing two boxes symmetrically one on each side of the web, similar variations are, of course, within the scope of the invention.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
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In coating a strip of material, such as web of paper, it is passed over a support member forming one of the enclosing surfaces of a closed chamber. The closed chamber is arranged to operate under vacuum conditions. Coating liquid is supplied in excess to the closed chamber to form a layer on the surface of the strip. At the end of the coating action, as the strip leaves the closed chamber, it is contacted by a movably positionable blade which provides a wiping-off action on the strip so as to remove the excess of coating liquid from the strip. The vacuum inside the closed chamber urges the blade against the strip. Therefore, it is possible, by varying the vacuum, to vary the amount of coating liquid adhering to the strip leaving the closed chamber.
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RELATED APPLICATIONS
This application is a continuation of application Ser. No. 735,829, filed Jul. 25, 1991, U.S. Pat. No. 5,141,037, which is a continuation of application Ser. No. 503,464, filed Apr. 2, 1990, U.S. Pat. No. 5,035,271.
BACKGROUND OF THE INVENTION
In a vapor recovery fuel dispensing nozzle of the general type disclosed in U.S. Pat. No. 3,866,636, No. 4,143,689, No. 4,235,266 and No. 4,418,730, it is common to use a pressure responsive check valve in the fuel line or passage within the nozzle body adjacent the inner end of the fuel dispensing spout. The check valve opens when fuel is supplied through the manually actuated control valve within the nozzle body, and a venturi suction or bleed passage extends from the annular seat of the check valve to the outer end portion of the spout. The venturi passage also extends to a diaphragm actuated mechanism which automatically closes the manually actuated valve when the bleed passage is blocked by fuel at the outer end of the spout. This form of automatic fuel shutoff is also commonly used in conventional fuel dispensing nozzles without a vapor return passage for a vapor recovery system.
One of the problems encountered with a vapor recovery fuel dispensing system is the accumulation of liquid fuel within the vapor return passage of the flexible coaxial hoses as a result of condensation of fuel vapors within the passage and the splash back of fuel during use of the dispensing nozzle for refueling. If too much liquid fuel collects within the vapor return passage defined between the coaxial hoses, the vapor return passage becomes blocked, and the vapor recovery system no longer operates.
One system for removing accumulated liquid fuel within the vapor return passage defined between coaxial hoses, incorporates a venturi system as disclosed in U.S. Pat. No. 4,687,033. In this patent, the venturi system is located within a coupling which-connects the coaxial hoses to the dispensing nozzle and includes a flexible rubber tube which extends downwardly into the annular vapor return passage defined between the coaxial hoses and terminates with an inlet located at the lowest point of the drape in the flexible hoses. The venturi system aspirates the liquid fuel within the vapor passage into the fuel supply passage which extends into the dispensing nozzle. The patent also mentions that the venturi system could also be located within the dispensing nozzle. Liquid fuel accumulated within the vapor return passage defined between the coaxial hoses has also been aspirated into the fuel supply passage by a venturi system located within the coaxial hoses at the lower most point of the drape in the hoses, and this venturi system is produced by Dayco Products, Inc.
The addition of a venturi aspirating system or device within the coaxial hoses or between the coaxial hoses and the dispensing nozzle as disclosed in above-mentioned U.S. Pat. No. 4,687,033, produces an additional flow restriction and pressure drop within the fuel supply passage extending to the dispensing nozzle. The flow rate reduction as a result of the additional restriction is on the order of 20% to 40%. Furthermore, the further upstream the venturi or aspirating device is located within the coaxial hoses, the higher the differential pressure that is required across the venturi or aspirating device to produce the desired suction. In order to obtain a higher pressure differential, the venturi must be more restrictive, which results in decreasing the flow rate.
The above-mentioned aspirating devices will not function properly below a minimum fuel flow rate such as 4 to 6 gallons per minute. To prevent a back flow of fuel through the venturi device and into the vapor return passage when the fuel flow rate is low due to partially opening the manually actuated flow control valve, a check valve is required in the venturi device. This check valve presents an additional pressure drop for which the venturi device must produce an additional pressure differential to overcome, thus further reducing the efficiency of the venturi device.
SUMMARY OF THE INVENTION
The present invention is directed to an improved vapor recovery fuel dispensing nozzle which incorporates a simplified and efficient system for removing or aspirating liquid fuel accumulated within the vapor return line or passage defined between coaxial hoses. The dispensing nozzle assembly of the invention also provides for a substantially higher fuel flow rate over other vapor recovery fuel dispensing systems with aspirating devices and, in addition, minimizes the cost and additional parts for incorporating an aspirating device in a vapor recovery fuel dispensing system.
In general, the above advantages and features are provided in accordance with the present invention by utilizing a single venturi device at the entrance of the fuel dispensing nozzle spout for obtaining dual functions. That is, the venturi device of the invention provides the conventional function of producing an air suction for actuating the diaphragm mechanism which automatically closes the manually actuated valve when the air suction bleed line within the fuel spout is blocked by fuel. In addition, the venturi device of the invention also functions to produce a suction to a passage which is connected by a tube extending through the nozzle body. The tube connects with a flexible tube which is laterally stiff and extends through the swivel connection and downwardly into the vapor return passage defined between the coaxial hoses.
Since the venturi device of the invention eliminates the need for a second venturi device or system within the fuel supply line, the fuel flow rate of the vapor recovery dispensing system is not decreased so that the desired maximum fuel flow rate of 9.5 to 10 gallons per minute may be obtained. Furthermore, since the venturi aspirating device of the invention is located at the inner end of the fuel dispensing spout where the maximum pressure drop is produced, the efficiency of aspiration is substantially increased by the invention so that a higher volume of condensed fuel is aspirated from the vapor return passage for a given flow of fuel through the supply passage. The venturi system of the invention also operates with a low flow rate of fuel and eliminates the need for a check valve to prevent a back flow of fuel into the vapor return passage during low fuel flow rates.
Other features and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal section through a vapor recovery fuel dispensing nozzle constructed in accordance with the invention and when the fuel and vapor flow control valves are normally closed;
FIG. 2 is a an enlarged end view of the nozzle as taken generally on the line 2--2 of FIG. 1;
FIG. 3 is an enlarged fragmentary section of the fuel check valve and venturi device constructed in accordance with the invention and shown in FIG. 1;
FIG. 4 is a fragmentary elevational view of the nozzle shown in FIG. 1 and with a side portion broken away to show the vapor return passage and fuel evacuating or aspirating line within the nozzle;
FIG. 5 is a longitudinal section similar to FIG. 1 and showing the fuel and vapor valves in their open positions when the nozzle is in use for dispensing fuel;
FIG. 6 is an enlarged fragmentary section taken generally on the line 6--6 of FIG. 4;
FIG. 7 is an enlarged fragmentary section similar to FIG. 3 and showing the check valve and venturi device of the invention in its open and operating position; and
FIG. 8 is an enlarged fragmentary plan view of the nozzle assembly and with a portion shown in section as taken generally on the line 8--8 of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a vapor recovery nozzle assembly 10 which includes a cast aluminum body 12 having a tubular handle portion 14 and an annular outlet portion 16. The body 12 defines internal fuel supply passages 18, 19 and 21, and a flow control valve 22 controls the flow of fuel from the passage 18 into the passages 19 and 21 in response to pivoting of a manually actuated control lever 24 about a pivot pin 26. The valve 22 includes a valve member 28 which is normally closed (FIG. 1) by a compression spring 31 confined within a cup-shaped plug 33 threaded into the body 12. A plunger 34 extends from the valve member 28 and engages the control lever 24, and suitable packing 36 is compressed around the plunger 34 by a fitting 38 to form a fluid-tight seal. The actuating lever 24 is enclosed within a plastic lever guard 41 which is secured to the body 12 by a pair of crossed pins 43. A set of levers 46 and 48 are pivotly connected to the actuating lever 24, and the lever 48 has a series of ribs 51 for selectively receiving the end of the lever 46 when the lever 24 is griped and moved upwardly (FIG. 1) to open the valve 22, as shown in FIG. 5.
The body 12 also defines an internal vapor return passage 55 (FIGS. 2 and 4) which extends partially around a tubular portion 57 defining the fuel passage 18 within the handle portion 14. The vapor passage 55 extends from an enlarged internally threaded inlet portion 61 (FIG. 1) which receives an annular fitting 63 (FIG. 5). The fitting 63 rotatably supports a tubular sleeve 64 which is secured to one end of a flexible vapor return hose 65 by a molded plastic tube 66. As also shown in FIG. 5, the vapor return hose 65 defines an annular vapor return passage 67 which surrounds a flexible rubber-like fuel supply hose 68 which is concentric or coaxial with the outer hose 65. The fuel supply hose 68 is connected by a tubular coupling 71 which projects into the tubular portion 57 of the nozzle body 12, and the hose 68 defines a fuel supply passage 72 which is connected by the coupling 71 to the fuel supply passage 18 within the body 12. As apparent from FIG. 5, the sleeve 64 is free to rotate within the fitting 63, and the coupling 71 is free to rotate within the tubular portion 57, and suitable O-rings form fluid-tight seals so that the nozzle assembly 10 is free to swivel or rotate relative to the coaxial hoses 65 and 68.
An automatic shutoff mechanism 75 (FIGS. 1 and 5) is supported by the body 12 and includes a tubular support member 77 which projects into the chamber or passage 21 and has a general square top flange portion 79 which seats on the body 12. The tubular portion 77 is sealed to the body 12 and supports a tubular actuating element 82 having a lower end portion which receives the pivot pin 26 supporting the forward end of the control valve actuating lever 24. The tubular actuating element 82 has an enlarged cylindrical upper end portion forming a cage for a set of balls 84 which normally engage a tapered or frusto-conical shoulder within the tubular member 77.
The automatic shutoff or release mechanism 75 also includes a center actuating stem 87 which has a tapered portion for engaging the balls 84 and carries a set of three diaphragms 89, 91 and 93 sandwiched between the flange portion 79 of the member 77 and a set of cup-shaped disk elements 96, 97 and 98 secured to the body 12 by a set of screws 99 (FIG. 8). A light compression spring 102 normally urges the stem 87 inwardly or downwardly so that the balls 84 are cammed outwardly to engage the tapered seat within the member 77. When the element 87 is moved upwardly, the balls 84 are free to move inwardly out of engagement with the tapered seat so that the tubular actuating element 82 is free to move downwardly within the support member 77.
Referring to FIGS. 3, 7 and 8, the annular outlet portion 16 of the nozzle body 12 receives a support fitting or member 110 which is retained by a screw 111 and receives an annular seat member 112 defining a passage 113 and having an undercut tapered valve seat 114. The member 110 supports the inner end portion of a tubular fuel supply spout 116 having a downwardly turned end portion 118, as shown in FIGS. 1 and 5. The member 110 also defines a fuel supply passage 119 (FIG. 8) which connects the passage 113 to a fuel supply passage 121 defined by the spout 118. The passage 119 is divided by an internal rib portion 124 (FIG. 8) having a tubular portion 126 which receives a cylindrical stem portion 128 of a tapered check valve member 130. A compression spring 132 normally urges the valve member 130 against the tapered valve seat 114 to form a normally closed check valve.
The valve member 130 includes a pair of diametrically opposite cylindrical posts or pins 136 (FIG. 7) which projects axially into corresponding bores 138 formed within the valve seat member 112. The pins 136 and corresponding bores 138 interrupt the valve seat 114 and form two opposing semi-circular tapered flow passages 140 and 142 (FIG. 8) when the valve member 130 is moved to its open position (FIGS. 7 and 8) in response to the pressure of fuel within the passage 113.
The center rib portion 124 of the support member 110 also supports an overfill shutoff air bleed tube 144 which extends longitudinally within the spout 116 and has an outer end portion connected by an elbow 146 (FIG. 5) to a radial port 147 within the outer end portion 118 of the spout 116. The inner end portion of the shutoff air bleed tube 144 is connected by a passage or port 148 (FIG. 7) to an annular chamber 150 defined between the body portion 16 and the outer surface of the support member 110 and between two of three O-ring seals 151. A suction port 152 (FIGS. 6 and 7) connects an adjacent annular chamber 153 to the shutoff mechanism 75 between the diaphragm 89 and the rolling bellows diaphragm 91, as shown in FIGS. 1 and 5. As shown in FIG. 8, the chambers 150 and 153 are connected by a pair of radial ports 154 which extend through the body portion 16 and through a rolling diaphragm valve element 155.
Referring to FIGS. 6-8, when the tapered valve element or member 130 is shifted to its open position, the arcuate flow passages 140 and 142 are separated by the pins or posts 136. A first venturi suction port 156 (FIG. 6) extends from the arcuate passage 140 to the annular chamber 153. As fuel flows through the passage 140, a suction is created within the port 156 and in the annular chamber 153. Air is sucked into the annular chambers 150 and 153 through the ports 148 and 154 and the overfill shutoff air bleed tube 144. However, when the air bleed port 147 within the outer end portion of the spout 118 is blocked by fuel, an increased suction is created within the chambers 150 and 153 and above the diaphragm 89 of the shutoff mechanism 75 through the port 152. As the stem member 87 moves upwardly due to the suction above the diaphragm 89, the balls 84 shift inwardly and release the tube 82 for downward movement so that the pivot support 26 for the handle 24 is released, and the fuel flow control valve 22 returns to its normally closed position in response to the force exerted by the spring 31.
Referring to FIG. 6, a second venturi suction passage or port 160 connects the fuel passage 142 to a suction port defined by a small tube 163 which extends from the seat member 112 radially outwardly through the annular chamber 153 and through a boss portion 166 of the nozzle body 12. A vapor valve plate 168 (FIG. 6) is secured to the boss portion 166 by a set of screws 171 (FIGS. 4 and 6) and defines a suction or evacuation port 172 (FIG. 8) forming an extension of the port within the tube 163. A deformable or flexible plastic evacuation tube 175 (FIGS. 4 and 8) extends rearwardly from the cover plate 168 through the vapor passage 55 within the nozzle body 12 and connects the port 172 to a suction or evacuation passage 178 (FIG. 2) defined within a flexible evacuation tube 180.
As shown in FIGS. 1 and 2, the inner end portion of the tube 180 extends into a recess within the tubular portion 57 and is secured to the nozzle body 12 by an arcuate retainer or holder 182 which is swagged to the tube and is secured to the body by a pair of screws 183. As also shown in FIG. 2, the flexible evacuation tube 180 is preferably molded of a flexible plastics material and has a width substantially greater than its thickness so that the tube is provided with substantial lateral stiffness. As shown in FIG. 5, the tube 180 extends from the nozzle assembly 10 downwardly into the draping coaxial hoses 65 and 68 and has an inlet end portion within the lowermost portion of the annular vapor return passage 67 defined between the coaxial hoses 65 and 68. The lateral stiffness of the evacuation tube 180 assures that the tube usually remains in the lower portion of the annular vapor return passage 67 when the nozzle assembly 10 rotates or swivels relative to the coaxial hoses during use of the nozzle assembly for dispensing fuel.
Referring to FIGS. 1 and 5, a flexible and collapsible vapor recovery bellows 190 surrounds the fuel dispensing spout 118 and defines an annular vapor return passage 192 around the spout. The bellows 190 has an inner end portion 194 (FIG. 3) which is secured by a band 196 to the outer end portion of a tubular fitting 198 slidably supported by a cylindrical sleeve portion 199 of the nozzle body 12. As shown in FIG. 8, a stop pin or stud 202 is supported by the sleeve portion 199 and projects radially inwardly into an axially extending slot 203 within the fitting 198 to limit axial movement of the fitting within the sleeve portion 199. A compression coil spring 206 normally urges the fitting 198 outwardly to the extended position shown in FIG. 1, and a resilient O-ring 207 forms a fluid-tight seal between the fitting 198 and the sleeve 199. An annular cup element 210 (FIG. 1) is secured by a band 211 to the outer end portion of the bellows 190 and retains a resilient annular cup-shaped seal or gasket 214.
When the nozzle assembly 10 is used for dispensing fuel, and the spout 118 is extended into the inlet tube (not shown) extending from a fuel receiving tank, the gasket 214 engages the outer end of the fill tube, and the bellows 190 is compressed from its normal position (FIG. 1) to a collapsed position (FIG. 5). The force required to collapse the bellows 190 is sufficient to move the fitting 198 inwardly within the sleeve 199 to compress the spring 206, as shown in FIGS. 7 and 8. A notch or recess 218 (FIG. 8) is formed within the inner end portion of the fitting 198 and aligns with a hole or port 221 within the sleeve portion 199 when the fitting 198 is depressed inwardly. Another aligned hole or port 222 is formed within the plate 168, and the port 222 is normally closed by a vapor valve member 225 pivotly supported by a pivot pin 226 secured to ears projecting from the plate 168.
A compression spring 228 (FIG. 8) extends between the vapor valve member 225 and a cup-shaped cover member 230 (FIG. 6) which encloses the valve member 225 and defines a vapor return passage 232 for connecting the vapor return passage 192 within the bellows 190 to the vapor return passage 55 within the nozzle body 12 when the valve member 225 is open. The valve member 225 seats against a resilient O-ring 233 retained by the plate 168 and has a stud portion 234 (FIG. 8) which projects inwardly into the recess 218 within the fitting 198 so that the valve member 225 is pivoted to an open position (FIG. 8) when the fitting 198 is depressed inwardly into the sleeve portion 199.
As shown in FIG. 6, a vapor pressure port 238 connects the vapor return passage 232 to the chamber directly under the diaphragm 93 of the shutoff mechanism 75. In the event the vapor pressure within the chambers or passages 232 and 55 exceeds a predetermined upper limit, for example, ten inches of water, the actuating stem 87 is moved upwardly to release the balls 84 and permit the tube 82 to move downwardly for releasing the handle 24 and shutting off the flow control valve 22. As also shown in FIG. 8, when the valve member 225 pivots inwardly to close the vapor return port 222, the valve member 225 has a tip 241 which projects through a hole within the plate 168 and depresses the rolling diaphragm valve element 155 to close the passages 154 connecting the annular chambers 150 and 153. Thus any venturi suction within the passage 156 and chamber 153 when the vapor valve member 225 is closed immediately actuates the mechanism 75 to release the handle 24 and close the valve 22.
From the drawings and the above description, it is apparent that a vapor recovery fuel dispensing nozzle constructed in accordance with the present invention provides all of the desirable features and advantages mentioned above in the "Summary of the Invention". For example, by having two separated and independent venturi or suction ports 156 and 160 extending from the check valve seat 114, only one venturi system is required to actuate the automatic shutoff mechanism 75 and to aspirate liquid fuel accumulated within the vapor return passage 66 within the coaxial hoses. As a result, a higher flow rate is obtained through the coaxial hoses and the dispensing nozzle assembly 10. In addition, the substantial pressure drop to atmosphere across the check valve member 130 produces a higher suction and thus more efficient aspiration of liquid fuel from the vapor return passage. As a result, aspiration of condensed fuel within the vapor return passage 67 is obtained even with a relatively low fuel flow rate around the valve member 130. It is also apparent that the use of the valve member 130 and the separate venturi passages 140 and 142 for aspirating fuel from the vapor return passage as well as actuating the automatic shutoff mechanism 75, eliminates the need for a separate upstream aspirating system and the associated flow restriction, such as disclosed in above mentioned U.S. Pat. No. 4,687,033.
While the nozzle assembly herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise assembly, and that changes may be made therein without departing from the scope and spirit of the invention as defined in the appended claims.
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A fuel dispensing nozzle includes a nozzle body and a projecting spout and surrounding bellows which define a fuel supply passage and a vapor return passage connected to corresponding concentric passages within flexible coaxial hoses. The body supports a manually actuated control valve within the fuel passage, and a pressure responsive check valve is also located within the fuel passage adjacent the spout. The check valve includes a valve member normally biased against a tapered valve seat, and a first venturi suction passage extends from the valve seat to control a pressure responsive diaphragm mechanism for automatically closing the manually actuated valve when fuel blocks a suction vent line within the of the spout. A second venturi suction passage extends from the valve seat through the nozzle body and connects with a fuel evacuation passage within a flexible tube which extends downwardly into the vapor passage within the coaxial hoses. The vapor return passage within the nozzle body is normally closed by a spring biased valve member which opens in response to collapsing of the bellows, and excessive vapor pressure within the vapor passage also operates the diaphragm mechanism to close the manually actuated valve.
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FIELD OF THE INVENTION
This invention relates to data processing systems including special conversion circuitry for changing data into special code groups which permit higher density recording.
BACKGROUND OF THE INVENTION
In systems for the magnetic recording of digital information, it has previously been proposed to convert the input data into special longer code groups and to indicate the presence of a "1" by a magnetic transition from one state to another. An article which discloses such a system and its advantages is entitled "A New Look-Ahead Code for Increased Data Density" by George V. Jacoby, presented at INTERMAG, June, 1977.
In the Jacoby article, three data bits are converted into six code bits, with each binary "1" being spaced apart by at least two binary "0's", and this restriction is carried over even to interfaces between adjacent code groups through certain logical algorithms. However, the nature of the system proposed in the above-mentioned article is such that transitions from one magnetic state to the other need occur only every second code group, or once every 12 code bits and that data patterns may occur when the spacing is repeated indefinitely. This requires a very tightly controlled phase-locked oscillator that is capable of maintaining accurate clocking with a sustained pattern of one flux transition every 12 clock periods. In addition, the selection of groups of three data bits to produce the six bit code groups which are formed is generally incompatible with most data processing circuits which utilize and process digital information in eight bit "bytes", or in four bit half-bytes, where two half-bytes form a byte. This incompatibility results in the need for additional buffering circuitry as the information is transferred from the data processing circuit to magnetic storage, and additional buffering as the groups of three bits are received from magnetic storage and supplied back to the data processing circuitry which operates with eight bit bytes or four bit half-bytes.
Accordingly, one important object of the present invention is to develop a high density magnetic recording system which is efficient and inexpensive with data processing systems which operate on eight bit bytes or four bit half bytes.
Another object of the present invention is to increase the minimum sustained frequency of magnetic transitions in the encoded data, without sacrificing density of recording, to thereby substantially reduce the constraints or requirements on the phase lock oscillator which generates the timing or clocking signals for the system.
SUMMARY OF THE INVENTION
In accordance with one aspect of the invention, a new eight bit code has been developed in which each recorded code group always includes at least one binary "1", and in which the eight bit code represents four binary digits, or a half-byte of data as used in the associated data processing circuitry.
In accordance with a coordinate aspect of the invention, the phase lock oscillator which generates the clocking signals for the system may be of simpler construction than had previously been employed, as the minimum sustained frequency of occurrence of magnetic transitions, from which the oscillator timing signals are obtained, is greater than previously available in such systems. Conversely, for a phase locked oscillator of given design this encoding method should provide an improved data decoding margin compared to the Jacoby method, thus resulting in improved data transfer reliability.
One advantage of the present system is the minimization of buffering circuiry both in transferring information from the data processing circuitry to the magnetic recording or storage, and in returning information from storage to the data processing system so that the data processing circuit is more directly coupled to magnetic storage unit.
In accordance with a specific illustrative implementation of the invention, the encoding circuitry for converting four bit data groups into eight bit code groups includes a "write PROM" or "Programmable Read Only Memory", which has as inputs the four data bits and also the next-to-last bit from the prior eight bit code group. As outputs, the "write PROM" has the first finalized six bits of the new code group, the provisional seventh (or next to last) bit of the new code group, and the last bit of the previous code group. The last bit of the previous code group from the "PROM" is combined with the next-to-last bit retained from the previous code group in a logic circuit providing an "exclusive-or" function, so that, if the last digit of the previous code group is a "1", the next-to-last digit must be a "0". In this way, the constraint that the stream of code digits which is magnetically recorded includes binary "1's" not more frequently then every third bit, is maintained. Hence the encoding circuit for converting for bit data groups into eight bit code groups is simplified, and essentially includes only two shift registers and a "PROM" having a five bit input. The same type of logic circuit can be employed in similar data group to code group conversions, in which the data and code groups are longer or shorter than that described in detail above.
The decoding circuitry is similar in the reconstitution of the four bit half-bytes of data from the special eight bit code groups; and the reading and writing circuits alternate in the utilization of the pair of shift registers which buffer the serial inputs and outputs from the data processing circuitry with the read and write PROMS.
Other objects, features and advantages of the present invention will become apparent from a consideration of the following detailed description and from the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall block circuit diagram of a system illustrating the principles of the present invention;
FIG. 2 is a diagram indicating the code groups which are developed from successive four bit data groups, and how the code groups may depend on the last bits of the preceding code group;
FIG. 3 is another diagram, illustrating a typical code group where reversal of certain digits is required at the transition between successive eight bit code groups; and
FIG. 4 is a logic circuit diagram showing the implementation of the code pattern as set forth in FIG. 2 of the drawings.
DETAILED DESCRIPTION
Referring more particularly to the drawings, FIG. 1 is an overall block diagram showing a data processing system 12, and a magnetic recording unit 14. The data processing circuit 12 is conventional in that it processes data in eight bit bytes or four bit half bytes. In the input circuit between the data processing system 12 and the magnetic recording unit 14 are the logic encoding and decoding circuit 16, which converts four bit data groups into eight bit code groups as discussed in more detail below, and a magnetic recording driver circuit 20 which energizes the magnetic write head 22, to reverse the polarity on the disc 24 upon the occurrence of binary "1's" in the stream of code bits supplied from logic circuit 16 over lead 72. The read head 26 receives encoded information from the disc 24, supplies it to the amplifier 28 from which it is routed to the phase lock oscillator and timing signal generator circuit 30 and to the logic decoding circuit 16 over lead 31. Timing or "clock" signals are routed on leads 34 and 36 to the decoding circuit 16 and to the data processing system 12, from circuit 30.
In the system of FIG. 1, and as will be disclosed in detail in FIG. 4 successive groups of four data bits supplied from the data processing system 12 to the logic conversion circuit 16, and the output from circuit 16 is a corresponding series of eight bit code groups which are eventually recorded on the magnetic disc 24.
In FIG. 2, the right-hand columns designated P-0 through P-7 represent the digital output from the logic conversion circuit 16, to driver circuit 20, as will be explained in greater detail below. However, the code group may depend, particularly at the interface between successive code groups, on the value of the digits in the last two digit places of the prior code group. Accordingly, to the left of the eight columns which are designated P-0 through P-7 of the "new code group" are included two bits, P-6 and P-7, of the prior code group. Incidentally, it may be noted that there are always at least two "0's" between each "1" in the code groups and this requirement is carried over to the transitions between code groups. To the left in FIG. 2 are the addresses to a programmable read-only memory or "PROM" which is a key component included within the logic conversion circuit 16 of FIG. 1. Incidentally, the "PROM" also appears at reference numeral 44 in FIG. 4, as will be discussed in detail below.
Now, returning to FIG. 2, the address to the PROM shown in the two left-hand columns of this diagram is set forth in what is known as "hexadecimal" form. When hexadecimal notation is used, a number is presented not in the decimal system, but in a system which has as its base 16, instead of 10. In counting in a hexadecimal system, one counts from 0 up through 9, and then instead of using double digit numbers to represent 10 through 15, the letters A through F are employed. Accordingly, when considering various addresses to the PROM which are set forth in the left-hand two columns of FIG. 2, the first address is "00", and represents the 0 address to the PROM, and results in an output code group from the PROM as shown to the right in the corresponding columns in FIG. 2. Similarly, the address "06" is the number 6 input to the PROM and produces the indicated output code group. Going on to the hexadecimal designations, the output "0C" refers to address number 12 of the PROM and again produces the indicated output code group shown to the right, possibly modified as discussed below.
The fifth input to the PROM is the next-to-last digit of the prior code group, designated "P-6". This appears as a "0" or a "1" as the most significant digit of the PROM address. Note that the first 16 entries in FIG. 2 have a 0 as the first digit of the PROM address, and this means that the code digit P-6 of the prior code group was a "0". However, in the second set of 16 code groups shown in the lower part of FIG. 2, the first digit of the PROM address is "1" indicating that P-6 from the prior 8 bit code group was a "1". Now, in each case the value of P-7 in accordance with the initial conversion is a 0. In order to satisfy the previously stated requirement that each "1" in the stream of code group bits be separated by two 0's, it is necessary when certain combinations appear at the transition between code groups, to reverse certain digits. For example, consider the primary conversion set forth adjacent the top or "00" PROM address. In this case P-0 is a "1". Now, with both P-6 and P-7, the last two bits of the prior code group both being equal to "0", there is no problem, and the criterion that two "0's" must appear between each "1" is satisfied. However, if P-6 from the prior code group had been a "1", this would have violated the criteria and a change would have been needed.
FIG. 3 is a diagram showing how such a change is made. In FIG. 3 the prior code group is shown to the left, with the 8 digits P-0 through P-7 appearing for the four data bits D-0 through D-3 and the 8 bits P-0 through P-7 of the new code group constituting the translation of the data bits D-4 through D-7. It may be noted that, as originally written, P-6 and P-7 of the prior code group were a "1" and a "0", respectively. In addition, P-0 of the new code group was a "1". Accordingly, there was only one "0" between P-6 of the prior group and P-0 of the new group. Therefore, a change must be made. In accordance with the logical rules which have been developed, the code group "101" is changed to the code "010", and this change produces a pair of allowable code groups forming an allowable pattern which may be encoded, as indicated by the lowest line in FIG. 3. Unlike the upper train of bits in FIG. 3, the lower bit train includes at least two "0's" between each "1", and thus meets the high density encoding requirement of the system.
On a more general basis, the rule indicated in the diagram of FIG. 3 is, first, perform a primary conversion, with P-7 always being equal to 0, and therefore not necessarily appearing as an output from the PROM; and then secondly, look at the new P-0 and the old P-6 and if they are both "1's", change the old P-6 and the new P-0 to "0's" and substitute between them P-7 equal to "1".
Consideration will now be given to the detailed logic circuit diagram of FIG. 4 which shows the implementation of at least a key portion of the logic conversion circuit 16 of FIG. 1. In FIG. 4, the encoding arrangements will first be considered; and the decoding and the common use of certain circuits for both encoding and decoding will then be examined.
Initially, it may be noted that an important component in the circuit is the "write PROM" or programmable read only memory 44. The PROM 44 has five inputs, including the right-hand lead which is designated P-6 as it carries P-6 from the prior code group, and the leads designated D-0 through D-3 extending from right to left in FIG. 4 at the top of the PROM 44, and representing the four digits of the half byte of digital information which has been stored in the four bit shift register 46, after having been received over lead 68 in serial input form. The PROM 44 samples D-0 through D-3, and prior P 6 just as D-3 is arriving at the input to the shift register 46.
The outputs from the bottom of the PROM 44, as shown in FIG. 4, are seven bits of the new code group designated P-0 through P-6, and also at the far right, P-7 for the prior code group. Now, below the PROM 44 are two four bit shift registers 48 and 50 which are linked together to form an eight bit shift register. The inputs to the shift registers 48 and 50 are first (from right to left in FIG. 4) the code bit P-6 associated with the prior code group, which will be developed as discussed below, and then P-7, the last bit of the prior code group, and these are followed by P-0 through P-5 of the new code group. Note that the P-6 digit of the new code group as intitially formulated in accordance with the primary conversion (upper portion of FIG. 2) is not routed to one of the shift registers 48 or 50 but is coupled via leads 52 and 56 to the left-hand input at the top of shift register 46. The timing is such that P-6 is entered in the first or left hand stage of shift register 46, and is shifted across, along with digits D-0, D-1 and D-2, so that at the time the output from Write PROM 44 is sensed, P-6 appears at output lead 57 at the output from register 46 and at the input to PROM 44. The prior P-6 also appears on lead 58 to the input 60 to the exclusive OR circuit 62. The other input to the exclusive OR circuit 62 is the digit P-7, also from the prior code group.
In passing, it is noted that "AND", "OR", and "EXCLUSIVE-OR" logic circuits are well known in the data processing field with an "AND" circuit providing an output only if all inputs are energized; an "OR" circuit providing an output if any input is energized; and an "EXCLUSIVE-OR" circuit providing an output if one but not both of its two inputs are energized.
Now, the steps in developing the changed code group as indicated in FIG. 3 will be briefly reviewed. First, normally, D-7 of the new group is not developed, because it is always, as a primary conversion (see upper portion of FIG. 2) considered to be 0. Therefore, the P-7 output from the PROM which appears as the far-right-hand output of the eight outputs at the bottom of PROM 44, is P-7 of the prior code group. Of course, both P-7 of the prior code group and P-0 of the new code group are automatically reversed, when appropriate, by virtue of the logic within the PROM 44, to produce the values for these two code bits as shown in the final lowermost line in FIG. 3. However, if old P-8 is a "1", this means that the old P-6 was also a "1", and accordingly, by virtue of the logic of the exclusive OR circuit 62, P-6 becomes a "0". This completes the logic inversion required for the few types of combinations when it is required. Incidentally, these five combinations are indicated by arrows extending inwardly at the lower left hand side of the table of FIG. 2, and inspection shows that these code groups where changes are required involve both the old P-6 initially being a "1" (lower half of FIG. 2), and the new P-0 also initially being a "1" (as shown in the corresponding original code groups in the upper portion of FIG. 2).
Of course, other collateral logic circuits of a conventional nature are also included in the circuitry discussed above in connection with FIG. 4. For example, circuit 66 is a multiplexer which selectively supplies data over lead 68 to the four bit shift register 46. During other time intervals, check bits or error correction bits may be supplied from multiplexer 66, in four bit "bytes", and encoded in the same manner as other data. Concerning other input leads shown in FIG. 4, these are conventional timing and control inputs.
Lead 72 at the output from the last stage of shift register 50 corresponds to lead 72 as shown in FIG. 1, with the eight bit shift register made up of registers 48 and 50 being operated as a single unit to provide a continuous stream of serial binary digits on lead 72. In the foregoing description, the encoding function involving converting groups of four serial data bits from multiplexer 66 on lead 68, into special eight bit code groups at lead 72, has been discussed. Now, the decoding function, involving the receipt of eight bit code groups which appear serially on lead 76 at the left of shift register 48, and the transmission of corresponding four bit serial data groups back to the data processing system on lead 78 from shift register 46, will be considered.
Initially, from an overall standpoint it will be useful to note that the shift registers 46, 48 and 50 are used, in different modes, for both the encoding and decoding functions. Further, when information is being stored on the magnetic disk 24 the write PROM 44 is enabled, and read PROM 82 is disabled and when information is being retrieved from storage, the read PROM 82 is enabled and the write PROM 44 disabled. These last functions are accomplished by the logic control signals designed "REN" or "read enable", and its inverse, designed "REN/", applied on leads 84 and 86 to PROMS 44 and 82, respectively.
Now, in the decoding function, coded information received on lead 76 is stepped through the eight bit shift register including registers 48 and 50; and when the last bit P-7 of the prior code group is at the last output register location of shift register 50, and the eight bits from the next code group are spaced along the other seven register locations of registers 48 and 50, with the last bit P-7 of the new code group at the input to register 48, the latching register 88 is enabled to hold the binary pattern at the input to the read PROM 82. In passing, it may be noted that latching register 88 may be dispensed with, if the Read Prom 82 has a sufficiently fast access time. Incidentally, an OR circuit 90 (or an exclusive OR circuit) combines P-6 and P-7 of the new code group to provide one of the eight inputs to read PROM 82.
The output from PROM 82 provides the original input four data bits, at the four output leads 92, in accordance with the inverse of the Table shown in FIG. 2, using the old P-7 and new P-0 through P-7 for conversion purposes. Incidentally, the output from the logic circuit 90 may be taken as equal to P-6 for the conversion purposes, as the presence of a "1" in either the P-6 or P-7 slot of the new code will indicate that P-6 was originally a "1". In passing, it may be noted that there are five pairs of different input eight bit code groups which will each give the same four bit output code groups. These are indicated by the arrows in the lower section of FIG. 2. Thus for example, both of the two eight bit code groups, in the order P-7, P-0, P-1 - - - P-6 which read 01001000, and 10001000 will produce an output on leads 92 of 0110, from D-0 through D-3, representing the number "6". These two code groups appear in the table of FIG. 2 under the PROM address designations 06 and 16 (with the initial "1" indicating that the prior P-6 code bit was a "1").
Returning to the circuit of FIG. 4, the four output leads 92 from the read PROM 82 are connected to input leads 96 to the successive stages of the shift register 46 toward the top of FIG. 4. Now, as the digits are shifted through shift register 46 from left to right, the four bit data half-byte appears serially at output lead 57 from the last stage of shift register 46 and is routed on lead 78 to the data processing system 12 as indicated in FIG. 1.
With regard to the phase lock oscillator 30, of FIG. 1, the design may be simpler as compared to that required by a system such as that cited hereinabove, or would have increased reliability, as discussed above, during the processing of random code groups. It may also be noted that the code pattern corresponding to repeated groups of "0" input data, as in typically used as a preamble for phase lock loop synchronization, has been specifically selected to yield a regularly spaced stream of flux transitions approximating the maximum frequency. This assists in the rapid synchronization of the phase lock oscillator.
Incidentally, it may be noted again that the logic encoding and decoding circuit 16 is coupled "directly" to the data processing system 12, to the exclusion of intermediate buffering circuitry for conversion from four bit half bytes to three bit data groups for encoding or the like; and in the present specification and claims the word "directly" shall have this significance.
In closing, it is to be understood the foregoing description is illustrative of the principles of the invention. Any suitable logic, storage, and data processing circuitry may be employed, and used with any of a wide variety of magneic disc or tape digital recording units. By way of example, but not of limitation, instead of using an "Exclusive-OR" circuit 62, other logic circuitry may be employed to make the logic value of P-6 a "0" when P-7 is a "1", as P-6 is always a "1" in order for P-7 to be a "1"; a single magnetic head may be employed for both reading and writing; and a single special memory essentially containing the table of FIG. 2 could be substituted for the two encoding and decoding PROMS as disclosed hereinabove. Accordingly, the present invention is not limited to that precisely as described hereinabove.
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A magnetic recording system is provided which encodes four bits of an eight bit "byte" at a time, and is thus compatible with most general purpose data processing systems which process eight bit bytes. Also, the special magnetic recording code groups which are formed have at least two "0's" between each "1", and always include at least one "1" in each code group, thereby increasing the average frequency of magnetic transitions and reducing the requirements for the phase lock oscillator timing circuit compared to previous methods. In addition, the conversion circuitry for converting from the short data groups to the longer code groups is simplified by the use of a small "Programmable read Only Memory" or "PROM" and "EXCLUSIVE-OR" circuit logic to insure proper code bit groupings of "1's" and "0's" within each code group and at the transitions between code groups. Similar simplifications are accomplished in the implementation of the "Read" decoding logic; and the shift registers for buffering to the "Read" and "Write" Programmable Read-Only Memories, are shared, thereby minimizing the expense of the required serial-to-parallel conversion and returning the PROM parallel output to serial form.
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BACKGROUND OF THE INVENTION
This invention relates to speed sensors and particularly to speed sensors of the flyweight type utilized in a turbine type of power plant's fuel control.
As is generally well known in technology encompassing fuel controls for turbine types of power plants, the fuel controls such as the JFC-12, JFC-25 and JFC-60 manufactured by the Hamilton Standard Division of the assignee and the type exemplified in U.S. Pat. No. 2,822,666 granted to S. G. Best on Feb. 11, 1958 and also assigned to the same assignee are designed on the W f/P × P principal,
Where W f = fuel flow in pound/hr.
P = compressor discharge pressure
This type of control which can be considered as having a logic network or computer section and a metering section monitors certain engine operating parameters such that during steady-state W f/P is made a function of compressor speed (N) and during acceleration W f/P is made a function of compressor speed and compressor inlet temperature (T T2 ). Thus, the fuel control serves to schedule fuel flow so as to achieve the desired engine speed while assuring that the flow of fuel does not permit surge, overheating, rich or lean blowout.
Under certain circumstances, one of the requirements of the fuel control is to provide for overspeed protection which may be needed during an emergency situation, such as where the flyweight speed sensor drive shaft malfunctions. In this event, the computer section positions the control linkage to an adjustable stop, generally known as the low speed saturation point which serves as the point where the speed servo provides the emergency schedule, based on a function of temperature manifested by the existing acceleration cam.
The problem encountered in certain fuel controls, however, is that the point at which the transition from the normal schedule to the emergency schedule occurs has been indiscriminate, inasmuch as the point at which the emergency schedule was activated or deactivated occurred over a wide variation of low speed saturations and that the speed of this transition was not repeatable. For purposes of starting the engine at a predetermined speed and prevention of overspeed at the low end of the speed spectrum, it is abundantly important that a particular speed at this transitory point and the repeatability of this speed be obtained.
By discovering the source of the problem which not only prevented the heretofore known fuel control to achieve the transitory point at a predetermined speed but repeating the speed at which the transitory point occurred we were able to obviate this problem in existing fuel controls. Thus, we found that a torsional spring applying a force to the flyweights at the low end of the speed spectrum served to define the transitory point so that it always occurred at substantially the same speed. By virtue of the torsional spring the loads applied to each face of the flyweights summed at its toes produce a force greater than the flyweight force at the low speed saturation condition, thus insuring that the thrust bearing is always preloaded and could not shift occasioned heretofore by the moment on the bearing caused by the feedback spring. Additionally, the torsion spring allows use of existing hardware with slight modifications and fits into the existing envelope which is not so for conventional leaf springs, or compression springs that require seats or method of attachment extraneous to useful functional hardware.
SUMMARY OF THE INVENTION
An object of this invention is to provide an improved speed sensor.
A still further object of this invention is to provide for fuel controls for a turbine type of power plant which fuel control provides a steady state/acceleration schedule and an emergency schedule, means for assuring that the transition from the steady state/acceleration schedule to the emergency schedule or vice versa occurs at a predetermined compressor speed.
A still further object of this invention is to provide for a fuel control of the type that includes a flyweight speed sensor, a pilot valve supported by a thrust bearing and where a speeder spring imparts a force through the pilot valve to match the force imparted by the flyweights, means for imparting a load on the flyweights through the pilot valve to preload the thrust bearing.
A still further object of this invention is to provide means for improving the accuracy and repeatability of existing fuel controls so as to assure that the emergency schedule is actuated or deactivated at a predetermined compressor speed by preloading the thrust bearing of the speed sensor pilot valve by a torsion spring biasing the flyweights and transmitting the biased force through the pilot valve to the thrust bearing, which means are characterized as simple, fits into existing hardware, is economical while incurring a minimal of additional weight.
Other features and advantages will be apparent from the specification and claims and from the accompanying drawings which illustrate an embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graphical illustration plotting W f/P vs. N showing the scheduling performed by the fuel control computing section.
FIG. 2 is a view partly in section, partly in elevation and partly in schematic illustrating the preferred embodiment of this invention.
FIG. 3 is a sectional view, not necessarily drawn in proportion, taken along lines 3--3 of FIG. 2.
FIG. 4 is a plan view of FIG. 2 showing the flyweight assembly.
FIG. 5 is a perspective view of the torsion spring.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention may best be understood by considering the problem that is solved as illustrated in the FIG. 1 graph. The fuel control serves to schedule steady state and acceleration as a function of certain engine operating parameters. For the details of typical fuel controls and their operation reference should be made to U.S. Pat. No. 2,822,666 supra and the above mentioned control models. Inasmuch as this aspect is not important to the understanding of this invention, for the sake of clarity and simplicity suffice it to say that the computer section, which monitors certain engine parameters, including power lever position, compressor inlet temperature, compressor discharge pressure and compressor speed, regulates fuel flow in accordance with the steady state schedule represented by curve A and the acceleration schedule represented by curves B. Additionally, the control at some determinant speed, say 10% of speed, is designed to switch from the acceleration schedule to the emergency schedule (left of vertical line C) in the event of certain malfunctions. However, it was found that the heretofore designed controls would reach the threshold of the transition points, instead of at the predetermined speed, at various speeds. At some times it was found that the point of transition occurred below the line C and at other times it occurred above. Not only would this result in an unwanted and intolerable overspeed situation at the low speed spectrum but also it hindered or prevented starting the engine if the switching from the schedule occurred beyond the engine start up point D.
What takes place in the fuel control can better be understood by referring to FIG. 2 which shows that portion of the computing section of a typical fuel control which manifests the acceleration schedule illustrated as curves B (FIG. 1) by positioning three dimensional cam 10 as a function of N and T T2 . This value is picked-off of the cam profile and transmitted to the other portion of the computer and metering section illustrated by box 14 by follower 12 where it is computed into the proper fuel flow in a well known state of the art manner. This cam also serves to provide the emergency schedule noted as curves E which vary as a function of T T2 .
As shown in FIG. 2, when follower 20 and flange 22 of 3-D cam 10 separate at the point where the platen 24 of the feedback link 26 bears against the adjustable low speed servo saturation stop 28, the speed of the compressor should be at or lower than the value of the transition line represented by vertical line C of the FIG. 1 graph, and the emergency schedule will control. However, owing to the nature of the speed sensor generally illustrated by numeral 30, the forces on the thrust bearing are substantially zero at this point of operation, so that it has the tendency to distort or shift, and any slight movement, although minute, adversely affects the accuracy and repeatability of the control.
It is to this problem that this invention affords a solution. As noted in FIGS. 2-5 speed sensor 30 comprises flyweights 34, pilot valve 36 and speeder spring 38. A buffer spring 40 opposing the compressor force of speeder spring 38 may be incorporated and serves to balance the load on pilot valve 36.
The flyweights in this particular configuration are mounted in a cup-like opened top member 42 which has depending therefrom shaft 44 rotary supported by bearings 46. Gear 48 secured to shaft 44 is driven by the driving mechanism 50 suitably driven by the compressor of the engine (not shown). Flyweight elements 52 and 54 are pivotally supported by bearing 51 to upstanding bifurcated member 56 integral with cup member 42 so that the centrifugal force is transmitted to the end of pilot valve 36 through the toes 58 and 60 of the flyweight elements 52 and 54 respectively. Thus, in operation, as the flyweights rotate, they transmit a load to the pilot valve, and obviously a change in RPM will cause this load to change and cause an unbalance. This in turn, positions pilot valve 36 to port regulated pressure obtained from a suitable source via line 60 either to chamber 62 (as shown) via annular passage 64, port 66, line 68, drilled passage 70 in stem 72 or to chamber 74 via annular passage 64, port 76, line 78 and drilled passage 80 in stem 72. The cylinder in this embodiment is cam 10 and it slides on stem 72 moving in the upward direction for a decrease in speed and in the downward direction for an increase in speed. Piston 82, suitably fixed to stem 72 separates chambers 62 and 74.
Obviously, when chamber 62 communicates with high pressure, chamber 74 will communicate with drain and vice versa. Hence, land 84 serves to direct fluid into port 76 through aperture 88, to drain port 86 (as shown) and land 90 directs flow to drain via aperture 92.
Thus, in normal governing operation the position of cam 10 is a direct function of compressor speed and follower 20 will be abutted against flange 22 to feedback this position through feedback linkage 26 to set the height of speeder spring 38. This obviously sets the compression load on spring 38 so that the load produced by flyweights 52 and 54 together with buffer spring 40 will ultimately equalize at which point the lands 84 and 90 will move on their line-on-line position with their adjacent ports, so that substantially no flow will be directed to or from chambers 62 and 74.
In accordance with this invention torsion springs 100 and 102 are incorporated to augment the force of buffer spring 40 by urging flyweights 52 and 54 radially outward so as to urge pilot valve 36 upwardly and preload bearings 32. In this particular embodiment the torsion spring is shaped in a substantially U-shaped member and the end of each of the legs of this U are bent to fit into a hole drilled into the faces of flyweight elements 52 and 54. Each spring may be designed to wrap around the stop bar 102. Since the diameter of the spring wire is relatively small it is fitted adjacent the side edges of the flyweight, requiring no changes in size of existing speed sensor and the only modification to the hardware is the drilled holes in the face of the flyweights. In another design, a single torsion spring was made to extend across the face of each of the flyweight elements and no holes were necessary.
By the addition of this spring load to the flyweights to preload bearings 32 it was found that the switching from one schedule to the other always occurred at substantially the same compressor speed.
It should be understood that the invention is not limited to the particular embodiments shown and described herein, but that various changes and modifications may be made without departing from the spirit or scope of this novel concept as defined by the following claims.
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A load on the flyweight transmitted through the pilot valve to preload the thrust bearings of a speed sensor serves to prevent the fuel control for a turbine type of power plant from shifting to its emergency schedule from the starting or normal schedule or vice versa at an indeterminant speed. Thus, the preload assures that the transition from one schedule to the other always occurs at a predetermined compressor rotational speed.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a retractable appliance control and method for using same. The preferred use for the invention is in a dishwasher, but the invention may be utilized in other appliances as well.
[0002] Disadvantage of prior control panels is that they are often contained within the door itself. The wires lead from the door to the other systems within the dishwasher. It is undesirable to route wires through a dishwasher door because the repeated flexing of wires at each opening and closing of the door results in wire fatigue and damage.
[0003] Another difficulty with prior art control panels is that they are located at the upper edge of the door and are usually vertically oriented. They are often positioned below the countertop and are difficult to view. Attempts to improve viewing of the controls have been made by angling the control panel surface, but this is limited due to space availability and also due to the shading or blocking created by the countertop overhang.
[0004] Another disadvantage of prior art control panels is that they are exposed at all times, and can be damaged by spills or dropped articles from the countertop.
[0005] Therefore, a primary object of the present invention is the provision of a retractable appliance control and method for using same.
[0006] A further object of the present invention is the provision of an appliance control which can be retracted when not in use, and which can be extended outwardly for use when desired.
[0007] A further object of the present invention is the provision of a retractable appliance control that presents its controls in an upward direction that can be easily viewed by the operator.
[0008] Another object of the present invention is the provision of a retractable appliance control that can be mounted either to the countertop or to the main cabinet of the appliance so that the control does not move with the door and wires do not need to be routed within the door.
[0009] A further object of the present invention is the provision of a retractable appliance control that minimizes the space used within the door.
[0010] A further object of the present invention is the provision of a control that can be mounted external to the door so that it can be located in the highest vertical position.
SUMMARY OF THE INVENTION
[0011] The foregoing objects may be achieved by an appliance control system which comprises in combination a control mounting frame having a control receiving recess therein. An electrical power system or interface is provided within the appliance for powering the functions of the appliance. The control system may be remote from the appliance or part of it. For example the control system could be retractably mounted below a cupboard.
[0012] The appliance control system includes a control panel having a panel housing and a plurality of control members on the exterior surface of the panel. At least one electrical connector connects the control members to the electrical power system for controlling the appliance. A bracket assembly mounts the control panel within the control receiving recess for movement from a recessed position wherein the control members are substantially contained within the control receiving recess to an extended position wherein the control members are outside the control receiving recess.
[0013] While the preferred appliance for this control system is a dishwasher, the control system may also be used in other appliances.
[0014] According to another feature of the invention the combination includes a countertop having front and rear edges, the cabinet being mounted below the countertop and having an upstanding front cabinet panel and a remaining cabinet housing. The front cabinet panel is positioned below the front edge of the countertop and the control receiving recess extends into the upstanding front panel.
[0015] According to a further feature of the invention the front cabinet panel is a door hinged for movement between an open and a closed position. The recess extends through the door into the remaining cabinet housing, and the bracket assembly connects the control panel to the remaining cabinet housing so that the control panel does not move with the door when the door moves between its open and closed positions.
[0016] According to another feature of the present invention a latch mechanism retentively engages the control panel and holds the control panel within the recess. A spring yieldably urges the control panel from the recessed position to the extended position. The latch mechanism is releasable to permit the control panel to move from the recessed to the extended position.
[0017] According to a further feature of the present invention a damping assembly is connected to the cabinet and to the control panel for resisting movement of the control panel from its recessed position to its extended position and from its extended position to its recessed position.
[0018] According to a further feature of the invention the damping assembly comprises a first damping member mounted to the cabinet for movement with respect thereto and a second damping member frictionally engaging the first damping member and the cabinet. The first damping member is movable in response to movement of the control panel between the recessed and extended positions.
[0019] According to a further feature of the invention a grease material is located between the first and second damping members and between the second damping member and the cabinet.
[0020] The damping mechanism can take several forms. One embodiment utilizes a circular disc which rotates, but provides a damping resistance to extension and retraction of the control panel. Another embodiment utilizes a rotatable gear engaging an elongated rack to provide the damping force. Other types of damping mechanisms may be used.
[0021] According to the method of the present invention the control panel is stored within a recess in, or separate from, the appliance cabinet. The control panel is then moved at least partially outside the recess so that the control members are exposed for manipulation to control the power system. After manipulation of the control members, the control panel can be moved back within the recess in the appliance cabinet.
BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS
[0022] [0022]FIG. 1 is a pictorial view of a dishwasher mounted beneath a cabinet and employing the retractable appliance control of the present invention.
[0023] [0023]FIG. 2 is an exploded perspective view of the retractable control panel of the present invention.
[0024] [0024]FIG. 3 is a sectional view taken along line 3 - 3 of FIG. 4.
[0025] [0025]FIG. 4 is a top plan view of the damping mechanism shown in FIG. 3.
[0026] [0026]FIG. 5 is a view similar to FIG. 4, but showing the damping mechanism in a different position.
[0027] [0027]FIG. 6 is a partial top plan view of the latching mechanism for the present invention.
[0028] [0028]FIG. 6A is a view similar to FIG. 6, but showing the latching mechanism in its latched position.
[0029] [0029]FIG. 6B is an enlarged view taken along line 6 B- 6 B of FIG. 6A.
[0030] [0030]FIG. 7 is a schematic view showing the relationship of the control panels to the systems for performing the appliance functions.
[0031] [0031]FIG. 8 is a plan view of a modified form of the present invention.
[0032] [0032]FIG. 8A is a front elevational view of the modification shown in FIG. 8.
[0033] [0033]FIG. 9 is a top plan view of another modified form of the present invention.
[0034] [0034]FIG. 9A is a front elevational view of the modification shown in FIG. 9.
[0035] [0035]FIG. 10 is a perspective view of a modified form of the invention.
[0036] [0036]FIG. 11 is a sectional view taken along line 11 - 11 of FIG. 10.
[0037] [0037]FIG. 12 is an enlarged view of the damping assembly taken along line 12 - 12 of FIG. 10.
[0038] [0038]FIG. 12A is a view similar to FIG. 12, but showing the gear in a different position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] Referring to FIG. 1, the numeral 10 generally designates a dishwasher. Dishwasher 10 includes a cabinet 12 having a front door 14 which is mounted at the front of a stationary cabinet housing 15 (FIG. 3).
[0040] A slide out control panel 16 includes a plurality of control buttons 18 on the upper surface thereof, and is mounted for sliding movement into and out of recess 20 . In its retracted position the front edge 26 of control panel 16 is preferably flush with the front face of door 14 . The control panel 16 is shown in its extended position in FIG. 1.
[0041] A countertop 22 includes a front edge 24 which is positioned above and adjacent the upper edge of the door 14 .
[0042] Referring to FIG. 2, the slide out control panel 16 , in addition to front panel edge 26 includes opposite side panel edges 28 , 30 and a rear panel edge 32 . Extending from the rear edge 32 is a control cable 34 .
[0043] Control panel 16 is attached to a bracket assembly 36 . Bracket assembly 36 includes a spaced apart pair of side tracks 38 which are fixed to a base plate 64 . Base plate 64 may be part of the cabinet 15 , or it may be a separate plate which is attached to the counter top 22 , or any other part of the counter. Bracket assembly 36 could also be one centrally mounted slide with Z side guides for stiffening.
[0044] Mounted for sliding movement within the spaced apart tracks 38 is a slide plate 40 having a corner cut out 42 forming an extended leg 44 . An oval aperture 46 extends through the leg 44 .
[0045] Panel 16 is attached to the slide plate 40 by means of screws 52 which extend upwardly through front screw holes 48 and rear screw posts 50 .
[0046] A damping assembly 54 includes a dish shaped disc 56 having an annular side wall 58 and a flat bottom wall 60 (see FIG. 3). A grease retainer 62 is mounted between the bottom wall 60 of disc 56 and the base plate 64 . A top plate 66 is positioned above the disc 56 and includes a radially extending top plate slot 68 . Beneath top plate 66 is a cone shaped spring 70 . A bolt 72 extends through top plate 66 and the bottom wall 60 of disc 56 , as well as the grease retainer 62 . The bolt 72 is threaded into base plate 64 , but there is a slight clearance between bolt 72 and the grease retainer 62 , the bottom wall 60 of disc 56 , and the top plate 66 so as to permit them to rotate relative to bolt 72 . The pressure that disc 56 applies to grease retainer 62 can be adjusted by rotating the bolt 72 , and this pressure is transferred to the disc 56 by means of the cone shaped spring 70 .
[0047] The grease retainer 62 is preferably made of a fabric which can be impregnated with grease so that grease engages both the bottom wall 60 of disc 56 and the upper surface of plate 64 . The grease, in combination with the pressure between disc 56 and grease retainer 62 causes the disc 56 to yieldably resist rotation.
[0048] An elongated rod 74 includes a beaded end 76 and an unbeaded end 78 . Rod 74 extends through a first aperture 80 (FIG. 3) which has a spring finger 82 that engages the beaded end 76 of rod 74 . Rod 74 extends through a second aperture 84 in the annular wall 58 of disc 56 , and then through the oval aperture 46 in the extended leg 44 . The aperture 46 has an oval shape so that leg 44 can move from the position shown in FIG. 4 to the position shown in FIG. 5 without any binding occurring between the rod 74 and the aperture 46 .
[0049] A spring 86 has an anchor end 88 which is anchored to the base plate 64 by means of a screw 90 . Spring 86 includes a rod end 92 which is attached to the rod 74 . The spring 86 is in tension so that it yieldably urges the rod 74 and the disc 54 to the left as viewed in FIG. 2. This exerts a yieldable force on the slide plate 40 toward its extended position. FIG. 2 shows the slide plate 40 in a partially extended position, but the spring 86 is adapted to move the slide plate 40 to its fully extended position. In the extended position the control buttons 18 are exposed vertically upwardly and can be easily seen and manipulated by the operator.
[0050] A latch member 94 is Y-shaped and is fixed to the upper surface of the base plate 64 . Latch member 94 includes a leg 96 and first and second Y-arms 98 , 100 . Positioned within the Y formed by legs 98 , 100 is a triangular member 120 having a first cam surface 122 spaced a short distance from leg 98 and a second cam surface 124 spaced a short distance from leg 100 .
[0051] A latch spring 102 has one end fixed to the slide plate 40 by means of an anchor screw 104 . The opposite end of spring 102 includes a pawl 106 . Two protrusions 126 , 127 engage the opposite sides of latch spring 102 to hold it in place.
[0052] The latch spring 102 is shown disengaged from the latch member 94 in FIG. 2. FIG. 6 illustrates the relative positions of the latch member 94 and the spring 102 . As the slide plate 40 is pushed inwardly into the recess 20 , the pawl 106 cams against the right-hand surface of the Y-leg 96 . Upon reaching the upper end of leg 98 the pawl 106 springs to the left and engages surface 122 of triangular member 120 . The pawl 106 then moves to the fork of the legs 98 , 100 while the slide 40 is at rest in its retracted position. FIG. 6A shows the slide plate 42 in its fully retracted position with the pawl 106 embraced between the two Y-legs 98 , 100 . In this position the spring 102 is exerting a slight force to the left as viewed in FIG. 6A.
[0053] When it is desired to move the control panel 16 to its extended position the control panel 16 is pushed inwardly and this permits the pawl 106 to spring to the left as viewed in FIG. 6A so that it rides around arm 100 . The spring 86 then causes the slide plate 42 to move to its extended position, and the pawl 106 cams along the left-hand surface of latch member 94 . When the pawl 106 moves out of engagement with the lower end of Y-leg 96 , it springs back to its original position shown in FIG. 6.
[0054] The damping assembly 54 provides a resistance to the sliding movement of slide plate 40 both from its retracted position to its extended position and also from its extended position to its retracted position. Referring to FIG. 4, the position of the damping mechanism is shown with the slide plate 40 in its fully extended position. FIG. 5 illustrates the position of the damping assembly 54 when the slide plate 40 is in its fully retracted position. As can be seen by comparison of FIGS. 4 and 5, the disc 56 rotates from the position shown in FIG. 4 to the position shown in FIG. 5. This movement is resisted by the frictional engagement between the disc 56 and the base plate 64 . The grease retainer 62 lubricates the movement between these two components, but the pressure between the two causes a damping action upon the extension and retraction of the slide plate 40 .
[0055] [0055]FIGS. 8 and 9 show modified forms of the present invention. A semicircular control panel 108 is adapted to pivot into a semicircular recess 109 about a pivot axis 110 . Conventional latching mechanisms and springs are well known in the art for controlling the movement of the control panel 108 between these two positions.
[0056] [0056]FIGS. 9 and 9A show a similar arrangement for a quarter circle panel 112 which fits within a quarter circle recess 113 and which pivots about a pivotal axis 114 .
[0057] Referring to FIG. 7, the control panel 16 is shown to be electrically connected to a microprocessor 116 which controls the various functions of the appliance systems as designated schematically in block 118 .
[0058] Referring to FIGS. 10 - 12 A a modified form of the control assembly is indicated by the numeral 128 . Control assembly 128 includes a control panel 129 which is movable from an extended to a retracted position. It is mounted for sliding movement with respect to a bottom panel or frame 130 . Bottom panel or frame 130 is comprised of a bottom plate 132 having side rails 134 and having mounted therein a U-shaped slide track 136 . Also attached to bottom panel or frame 130 is an elongated rack 138 having gear teeth 140 extending along one side thereof. A latch pin 142 (FIG. 11) is attached to the panel or frame 130 and extends upwardly therefrom. Attached to and extending upwardly from the front edge of the bottom plate 130 is a spring post 144 .
[0059] Control panel 129 includes an upwardly presented surface 146 having controls designated schematically by the numeral 148 , a front edge 150 , and side edges 152 adjacent the side rails 134 of bottom plate 132 for sliding movement with respect thereto. Attached to, and extending downwardly from the upper surface 146 is a spring post 154 . A spring 155 is attached at one end to the downwardly extending spring post 154 of control panel 129 and is connected at the other end to the upwardly extending spring post 144 of bottom panel or frame 130 . This spring biases the control panel 129 to its extended position shown in FIG. 11. In its retracted position with the rear edge 150 coinciding with the rear edge of the bottom panel 130 , the spring 155 is in tension and yieldably urges the control panel 129 toward its extended position. The sliding movement of control panel 129 with respect to bottom panel 130 is facilitated by a U-shaped slide track 156 attached to the panel assembly 129 and retentively slidingly engaging the U-shape slide track 136 of the bottom panel 130 .
[0060] A latching mechanism is provided for latching the control panel 129 in its retracted position, and includes a rotatable latch tumbler 158 having a spring arm 160 , a button arm 162 and a latch pawl 164 . Pawl 164 includes a cam surface 166 . A spring 168 is connected to the spring arm 160 and is also connected to the control panel 129 so as to yieldably urge the latch tumbler 158 in a clockwise direction as viewed in FIG. 11. A manually operable button 170 engages the button arm 162 of latch tumbler 158 , with a stop 171 in the housing limiting the rotational movement of latch tumbler 158 in a clockwise direction.
[0061] When the control panel 129 is moved to its retracted position, the cam surface 166 of latch pawl 164 engages the upstanding latch pin 142 of bottom panel 130 and causes the latch tumbler to cam in a counterclockwise direction against the bias of spring 168 . This permits the pawl arm 164 to move around the latch pin 142 and then spring in a clockwise direction to latch and retentively engage the latch pin 142 .
[0062] When it is desired to extend the control panel to its extended position the button 170 is pushed inwardly thereby releasing the pawl arm 164 from the latch pin 142 and permitting the control panel 129 to slide to its extended position in response to the bias provided by spring 155 .
[0063] The numeral 172 refers to a damping device mounted to the bottom of top 146 and extending downwardly therefrom to engage the elongated rack 138 . The damping device 172 includes a gear mounting member 173 having a pair of oppositely extending wings 174 and a circular central portion 175 . Rotatably mounted to the central portion 175 is a rotating gear 176 which meshes with the gear teeth 140 of elongated rack 138 .
[0064] Gear mounting member 173 is mounted for limited floating movement within a pocket formed by a pair of opposite end holders 178 and a pair of side holders 180 , 182 . The holders 178 each have an internal wall 179 , and the holder 180 includes a pair of driving bosses 183 . The damping device 172 is a product which is available from Ace Controls Inc. having an address of 23435 Industrial Park Drive, Farmington, Mich. 48335, under the Series No. G2.
[0065] [0065]FIGS. 12 and 12A illustrate the limited floating movement of the gear mounting member 173 within the pocket formed by end holders 178 , and side holders 180 , 182 . FIG. 12 shows the gear mounting member in a first position and FIG. 12A shows it in a second position. In FIG. 12 the central portion 175 of gear mounting member engages the side holder 180 . In FIG. 12A the central portion 175 engages the opposite side holder 182 . The floating movement of this gear mounting member permits the gear mounting member to take up tolerances within the assembly. The movement of the central portion from the position in FIG. 12 to the position shown in FIG. 12A is approximately 0.04 inches.
[0066] This permits the floating of the gear 176 so as to maintain the pitch circle of the gear 176 tangent to the pitch line of teeth 140 on rack 138 during both the retraction and the extension of the control panel 129 .
[0067] The gear 176 has a limited amount of friction which imparts a damping action to the retraction and extension of the control panel 129 . This imparts a smooth continuous movement of the control panel during its extension and retraction.
[0068] In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, these are used in a generic and descriptive sense only and not for purposes of limitation. Changes in the form and the proportion of parts as well as in the substitution of equivalents are contemplated as circumstances may suggest or render expedient without departing from the spirit or scope of the invention as further defined in the following claims.
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A control panel is retractably received within a recess in an appliance housing. The panel may be moved from an extended position wherein the control panel is exposed outside the cabinet to a retracted position wherein the control panel is enclosed within the recess. A spring urges the control panel to its extended position, and a latch is provided for releasably holding the control panel in its retracted position.
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BACKGROUND OF THE INVENTION
The transformation of 17-keto steroids to corticoids is well known to those skilled in the art. Numerous routes have been utilized. See, for example, U.S. Pat. Nos. 4,041,055, 4,216,159, 4,342,702 and 4,411,835.
The addition of an α-nitrile anion to ketones has been reported, see Synthesis 92 (1975), including 17-keto steroids, see J. Org. Chem. 43, 4374 (1978). The J. Org. Chem. 43, 4374 (1978) publication discloses the addition of the lithiated mono anion of 3-unsubstituted propionitrile to a 17-keto steroid to give a 17β-hydroxy-17α-substituted steroid which upon dehydration with thionyl chloride gives a 20-cyano-Δ 17 ( 20 )-steroid, however the oxidation of these 20-cyano- 17 ( 20 ) steroids to 17α-hydroxy 20-keto steroid does not work well, see J. Org. Chem. 44, 702 (1979). The -OR 21 substituent permits efficient oxidation of the 20-cyano-Δ 17 ( 20 )-steroid (III) to the corticoid (IV). The addition of a β-mettalo-α-substituted propionitrile to a 17-keto steroid has not been reported. It is surprising and unexpected that the α-metallo-β-metalloxypropionitrile dianion (V) adds to the 17-keto steroid (I) without elimination of the -OR 21 α substituent.
The oxidation of 21-acetoxy-Δ 17 ( 20 )-20-cyanopregnanes to the corresponding 17,21-dihydroxy-20-keto steroid derivatives is well known in the steroid literature, see J. Am. Chem. Soc. 76, 5031 (1954); J. Am. Chem. Soc. 70, 1454 (1948); J. Am. Chem. Soc. 71, 2443 (1949); J. Am. Chem. Soc. 77, 196 (1955); Helv. Chim. Acta 34, 359 (1951); and J. Org. Chem. 44, 702 (1979).
The process of the present invention transforms the 17-keto steroid (I) starting materials to the corresponding corticoid (IV) products in only four steps.
SUMMARY OF THE INVENTION
Disclosed is a 17β-hydroxy steroid (II A-C).
Also disclosed is a process for the preparation of a C 3 -protected 17β-hydroxy steroid (IIα) which comprises contacting a C 3 -protected 17-keto steroid (I) with an α-metallo-β-metalloxypropionitrile (V) at a temperature of less than about 0°.
Further disclosed is a process for the preparation of a corticoid (IV) which comprises (1) contacting a C 3 -protected 17-keto steroid (I) with an α-metallo-β-metalloxypropionitrile (V) to produce a 17β-hydroxy steroid (IIα), (2) contacting the 17β-hydroxy steroid (IIα) of step (1) with an acylating or silylating agent to produce a 21-hydroxy protected steroid (IIβ), (3) contacting the 21-hydroxy protected steroid (IIβ) of step (2) with a dehydrating agent to produce a Δ 17 (20)-20-cyano steroid (III) and (4) contacting the Δ 17 ( 20 )-cyano steroid (III) of step (3) with an oxidizing agent.
DETAILED DESCRIPTION OF THE INVENTION
The 17-keto steroid (I) starting materials are well known to those skilled in the art or can readily be prepared from known compounds by methods well known to those skilled in the art. These include Δ 4 -3-keto (A), Δ 1 , 4 -3-keto (B) and 3β-hydroxy-Δ 5 (C) steroids, see Chart B. The 17-keto starting materials can be substituted at C 6 , C 9 , C 11 and/or C 16 , with R 6 , R 9 , R 11 and R 16 as defined infra.
The A-ring of the 17-keto starting material must be protected, see, Protective Groups in Organic Synthesis, Theodora Greene, John Wiley & Sons, New York, 1981 and Steroid Reactions, Edited by Carl Djerassi, Holden-Day, San Francisco, 1962.
For the Δ 4 -3-keto steroids (A) the C 3 ketone is protected as the enol ether (Aa), ketal (Ab), or enamine (Ac) as is well known in the art, see Chart C. The preferred enol ether (Aa) is the methyl or ethyl ether. The preferred ketal (Ab) is the ethylene ketal. The preferred enamines are selected from the group consisting of pyrrolidino, morpholino and diethylaminoenamines. The enol ethers (a) are prepared by methods well known in the art, see J. Org. Chem. 26, 3925 (1961), Steroid Reactions, Edited by Carl Djerassi, Holden-Day, San Francisco, 1962, p 42-45, and U.S. Pat. No. 3,516,991 (Preparation 1). The ketals (b) are also prepared by well known methods, see Steroid Reactions, supra, p 11-14. The 3-enamines (c) are also prepared by methods well known in the art, see U.S. Pat. No. 3,629,298 and Steroid Reactions, supra, p 49-53.
The Δ 1 , 4 -3-keto steroids (B) are protected as the 3-dialkylenamine (Ba) or ketal (Bb), see Chart C and U.S. Pat. Nos. 4,216,159 and 4,357,279.
The 3-hydroxy steroid (C) should have the 3β-hydroxyl group protected as the ether (Ca), see Chart C.
The C 3 protected forms (Aa, Ab and Ac) of the Δ 4 -3-keto steroids (A), the C 3 protected forms (Ba and Bb) of the Δ 1 , 4 -3-keto steroids (B) and the C 3 protected form (Ca) of the 3β-hydroxy steroids (C) are considered equivalent to the non-protected or free form (A, B and C) respectively, since the C 3 protecting groups are readily removable to convert the C 3 protected forms (Aa, Ab, Ac, Ba, Bb and Ca) to the free or unprotected forms (A, B and C) respectively.
α-Metallo-β-metalloxy propionitrile (V), a dianion, can be prepared by treatment of 3-hydroxypropionitrile (HOCH 2 CH 2 CN) with a non-nucleophilic strong base in an aprotic solvent in a temperature range in which the dianion is stable. Suitable bases include lithium, sodium or potassium salts of disubstituted amines such as diisopropylamine, dicyclohexylamine, piperidine, diethylamine; bis(trialkylsilyl) amines such as hexamethyldisilazane and equivalents thereof. Suitable solvents include ethers such as THF, diglyme, ether; aromatic hydrocarbons such as benzene, toluene, xylene; hydrocarbons such as hexane, heptane, cyclohexane and mixtures thereof. The reaction temperature should be low, preferably less than about -20°, more preferably less than about -60°. The reaction should be performed under substantially anhydrous conditions in an aprotic solvent in the temperature range of about -20° to about -80°. About 2.1 equivalents of the base should be contacted at low temperature with the 3-hydroxypropionitrile. The α-metallo-β-metalloxy propionitrile dianion (V) is formed and kept under a nitrogen atmosphere under anhydrous conditions. The α-metallo-β-metalloxy propionitrile (V) is unstable at tempertures above about -20° . It is preferred to prepare 2.1 equivalents of lithium diisopropylamide from diisopropylamine and n-butyllithium in THF/hexane at about -40°; the 3-hydroxypropionitrile is then added to the lithium diisopropylamide at about -60° to prepare the α-metallo-β-metalloxy propionitrile (V). The preferred α-metallo-β-metalloxy propionitrile is the dilithio-3-hydroxypropionitrile, α-lithio-β-lithioxypropionitrile.
The C 3 protected 17-keto steroid (I) is reacted with the α-metallo-β-metalloxy propionitrile (V) to produce the C 3 protected 17β-hydroxy steroid (IIα).
The C 3 protected 17-keto steroid (I) is reacted with the α-metallo-β-metalloxy propionitrile (V) at about -20° to about -80° under anhydrous conditions. The C 3 protected 17-keto steroid is preferably added in solution or in a solvent in which it is at least partially soluble. The reaction is allowed to proceed until judged complete by TLC. The reaction mixture can be warmed once the reactants have been mixed. An excess of the α-metallo-β-metalloxy propionitrile (V) is usually advantageous but is not necessary. Once the reaction is complete the 17β-hydroxy-steroid (IIα) is isolated by means well known to those skilled in the art, the addition of water and/or a dilute acid followed by extraction of the product into an organic solvent to remove the inorganic salts. The C 3 -protected A-ring can have the protecting groups removed in situ if so desired by means well known to those skilled in the art i.e. an enol ether (Aa) can be removed with aqueous acid. The reaction upon workup produces the 17β-hydroxy steroid (IIα) where R 21 α is a hydrogen atom.
The C 3 protecting group can be removed from the C 3 protected (Aa, Ab, Ac, Ba, Bb or Ca) 17β-hydroxy steroid (IIα) to produce the 17β-hydroxy steroid (IIα) in its free or not protected form (A-C). If the C 3 protecting group is left on at this stage it can be removed later.
The 21-hydroxyl group (R 21 α is a hydrogen atom) is selectively protected as an acyl or silyl derivative, preferably as an acyl derivative to give the 21-hydroxy protected steroid (IIα).
The addition of the C 21 protecting group is accomplished by standard procedures; for example, acylation with acetic anhydride and pyridine; silylation with trimethylsilyl chloride as is well known to those skilled in the art. Regarding the acylation using acetic anhydride and pyridine is preferred to treat the 17β-hydroxy steroid (IIα) and pyridine with a slight excess of acetic anhydride under mild conditions to give the 17β-hydroxy 21-acetate (IIα). Other acylating agents can be used such as acetyl chloride, a mixed anhydride of acetic acid etc. Other acyl groups (-CO-R 21 ') include C 2 to C 6 or phenyl. The 21-hydroxy protected steroid (IIα) can be isolated by standard methods well known to those skilled in the art or can be treated in situ with a dehydrating agent to give the Δ 17 ( 20 )-20-cyano steroid (III).
The 21-hydroxy protected steroid (IIβ) is transformed to the corresponding Δ 17 ( 20 )-20-cyano steroid (III) by reaction with a dehydrating agent. Dehydrating agents such as thionyl chloride, phosphorous oxychloride or chlorosulfonic acid can be used to give the Δ 17 ( 20 )-20-cyano steroid (III). This is a similar reaction as to that reported J. Org. Chem. 43, 4374 (1978). The reaction with thionylchloride is best accomplished by addition of a slight excess of thionyl chloride at less than 0° preferably about -15°. Thionyl chloride is the preferred dehydrating agent. The mixture is then warmed to 0° and quenched with water. The Δ 17 ( 20 )-20-cyano steroid (III) can be isolated by means well known to those skilled in the art, --by extraction of the product into an organic solvent with removal of the inorganics and pyridine by aqueous washes. The product can be crystallized from the organic solvent to give the desired Δ 17 ( 20 )-20-cyano steroid (III).
The Δ 17 ( 20 )-20-cyano steroid (III) is transformed to the corticoid (IV) by reaction with an oxidizing agent as is well known to those skilled in the art, see J. Am. Chem. Soc. 76, 5031 (1954); J. Am. Chem. Soc. 70, 1454 (1948); J. Am. Chem Soc. 71, 2443 (1949); J. Am. Chem. Soc. 77, 196 (1955); Helv. Chem. Acta 34, 359 (1951); and J. Org. Chem. 44, 702 (1979). Suitable oxidizing agents include potassium permanganate, osmium tetroxide.
The use of potassium permanganate is preferred. In this case the Δ 4 , 3-keto (A) ring system must be protected, preferably as the ethylene ketal. In the first step, if the C 3 protecting group is an enol ether (Aa), the 17β-hydroxy steroid (II) will be the enol ether (Aa). The 17β-hydroxy steroid enol ether (IIAa) can be converted to the C 3 ethylene glycol protecting group by reacting the 17β-hydroxy enol ether (IIAa) with ethylene glycol and acid. The Δ 4 , 3-keto (A) ring system is then regenerated from the ethylene ketal by acidic hydrolysis as is well known to those skilled in the art, see J. Am. Chem. Soc. 76, 5031 (1954).
The corticoid (IV) products are useful as is well known to those skilled in the art.
DEFINITIONS
The definitions and explanations below are for the terms as used throughout the entire patent application including both the specification and the claims.
All temperatures are in degrees Centigrade.
TLC refers to thin-layer chromatography.
THF refers to tetrahydrofuran.
THP refers to tetrahydropyranyl.
EEE refers to ethoxy ethyl ether [--O--CH(CH 3 )OCH 2 CH 3 ].
p-TSA refers to p-toluenesulfonic acid monohydrate.
TEA refers to triethylamine.
NMR refers to nuclear (proton) magnetic resonance spectroscopy, chemical shifts are reported in ppm (δ) downfield from tetramethylsilane.
TMS refers to trimethylsilyl.
When solvent pairs are sued, the ratios of solvents used are volume/volume (v/v).
Ether refers to diethyl ether.
Androstenedione refers to androst-4-ene-3,17-dione.
M is a lithium, sodium or potassium ion.
M' is a lithium, sodium or potassium ion.
R is alkyl of 1 thru 6 carbon atoms or phenyl.
R' is alkyl of 1 thru 6 carbon atoms or phenyl.
R" is alkyl of 1 thru 6 carbon atoms or phenyl.
R 3 is an alkyl group of 1 thru 5 carbon atoms, with the proviso that with the ketal (Ab, or Bb) and the enamine (Ac and Ba) the R 3 groups can be the same or different and can be connected and with the enamine (Ac and Ba) if cyclized the ring can contain hetero atoms.
R 3 ' is an alkyl group of 1 thru 3 carbon atoms or a TMS, THP or EEE group.
R 6 is a hydrogen or fluorine atom or methyl group.
R 9 is nothing, a hydrogen, fluorine or oxygen atom which makes the C ring
(a) Δ 9 (11) when R 9 is nothing and
(b) 9β,11β-epoxide when R 9 and R 11 taken together are an oxygen atom.
R 11 is a hydrogen or oxygen atom, two hydrogen atoms, or α- or β-hydroxyl group which makes the C-ring
(a) Δ 9 (11) when R 11 is a hydrogen atom,
(b) 9β,11β-epoxide when R 9 and R 11 taken together are an oxygen atom and between C 11 and R 11 is a single bond, and
(c) a ketone when R 11 is an oxygen atom and between C 11 and R 11 is a double bond.
R 16 is a hydrogen atom or methyl group.
R 21 is a hydrogen atom, --CO--R 21 ', --SiRR'R" or M';
R 21 'is an alkyl group of 1 thru 5 carbon atoms or phenyl.
R 21 α is a hydrogen atom or M'.
R 21 β is a --CO--R 21 ' or --SiRR'R" group.
X is a hydrogen atom or nothing, when X is nothing the between XO and C 3 is a double bond and when X is a hydrogen atom the between the XO and C 3 is a single bond.
˜ indicates that the attached group can be in either the α of β configuration.
is a single or double bond.
When the term "alkyl of -- through -- carbon atoms" is used, it means and includes isomers thereof where such exist.
EXAMPLES
Without further elaboration, it is believed that one skilled in the art can, using the preceding description, practice the present invention to its fullest extent. The following detailed examples describe how to prepare the various compounds and/or perform the various processes of the invention and are to be construed as merely illustrative, and not limitations of the preceding disclosure in any way whatsoever. Those skilled in the art will promptly recognize appropriate variations from the procedures both as to reactants and as to reaction conditions and techniques.
EXAMPLE 1
17β-Hydroxy-17α-(2-hydroxy-1-cyanoethyl)androsta-4.9(11)-dien-3-one (II A)
Dry THF (300 ml) and distilled diisopropylamine (30 ml) are mixed and cooled to less than -50°. Over a period of 10 minutes n-butyl lithium and hexane (1.6 N, 125 ml) are added by an addition funnel. After 30 minutes at less than -40°, 3-hydroxypropionitrile (6.55 g, 63 ml) is added dropwise. The resulting mixture is brought to -40° over 15 minutes, than cooled back down to less than -65°. After a total time of 1 hour, 3-hydroxyandrosta-3,5,9(11)-trien-17-one 3-methyl enol ether (I Aa) is added as a solid in one portion. The resulting slurry is stirred at less than -65° for 2 hours, then slowly over a period of 1 hour, brought to 5°. A solution of saturated aqueous ammonium chloride (75 ml) is added and the two-phase mixture is brought to 20°-25° . The layers are separated and the aqueous layer is extracted with methylene chloride (2×150 ml). The organic extracts are combined and back-washed with water (2×150 ml) and concentrated under reduced pressure to give a semi-solid. The semi-solid material is slurried in methylene chloride (100 ml). The solids are isolated and washed with additional methylene chloride. The solid material is suspended in methylene chloride (100 ml) and treated with aqueous hydrochloric acid (6 N, 10 drops) at 20°-25°. The mixture is stirred for 24 hours during which time most of the solids dissolved. The resulting mixture is diluted with methylene chloride (150 ml), extracted with water (100 ml) and concentrated under reduced pressure to give a solid. The solid is triturated with ethyl acetate (100 ml) at 20°-25° for 16 hours and re-isolated to give the title compound. NMR (CDCl 3 ) 0.97, 1.37, 2.23, 3.32, 3.43, 4.17, 5.60 and 5.73 δ.
EXAMPLE 2
17β-Hydroxy-17α-(2-acetoxy-1-cyanoethyl)androsta-4,9(11)-dien-3-one (II A)
17β-Hydroxy-17α-(2-hydroxy-1-cyanoethyl)androsta-4,9(11)-dien-3-one (II A, Example 1, 3.55 g), dry pyridine (30 ml), acetic anhydride (1.23 ml) are stirred at 20°-25° for 18 hours, then poured into water (250) ml) and methylene chloride (150 ml). The layers are separated and the aqueous layer is extracted with methylene chloride (60 ml). The organic layers are combined, washed with aqueous hydrochloric acid (1 N, 100 ml), dried over sodium sulfate and concentrated under reduced pressure to give the title compound. NMR (CDCl 3 ) 0.98, 1.37, 2.13, 3.02, 3.18. 4.50, 5.60 and 5.75 δ.
EXAMPLE 3
20-Cyano-21-hydroxypregna-4,9(11),17(20)-trien-3-one 21-acetate (III A)
17β-Hydroxy-17α-(2-acetoxy-1-cyanoethyl)androsta-4,9(11)-dien-3-one (II A, Example 2) is dissolved in pyridine (30 ml) and the mixture cooled to less than -50° under nitrogen. Thionyl chloride (0.86 ml) is added dropwise. After 30 minutes the mixture is brought to 0° and treated with water (10 ml). The mixture is transferred to a separatory funnel with methylene chloride (100 ml) and water (250 ml). The aqueous layer is separated and extracted with methylene chloride (2×50 ml). The organic phases are combined and washed with aqueous hydrochloric acid (0.5 N, 100 ml), dried over sodium sulfate and concentrated under reduced pressure to a solid. The solid is recrystallized from ethyl acetate to give the title compound. NMR (CDCl 3 ) 0.98, 1.37, 2.12, 4.62, 5.57 and 5.73 δ.
EXAMPLE 4
20-Cyano-21-hydroxypregna-4,9(11),17(20)-trien-3-one 21-acetate 3-ethylene glycol ketal (III A)
20-Cyano-21-hydroxypregna-4,9(11),17(20)-trien-3-one 21-acetate (III A, Example 3, 70 ml), methylene chloride (2 ml), ethylene glycol (0.12 ml) and trimethylorthoformate (0.05 ml) are stirred at 20°-25°. p-TSA (3 mg) is added. After 1.5 hours at 20°-25° triethylamine (5 drops) is added and the solvent removed under reduced pressure to give the crude ketal as a mixture of Δ 4 and Δ 5 -isomers of the title compound.
EXAMPLE 5
17α-21-Dihydroxypregna-4,9(11)-diene-3,20-dione 21-acetate (IV A)
The ketal mixture of Example 4 is dissolved in dry acetone (2 ml) and ethylene glycol (0.6 ml). The mixture is cooled to 0°-5° and with stirring under nitrogen atmosphere potassium permanganate (80 ml) is added as a solid powder. After 4 hours aqueous sodium bisulfite (1.5 ml) is added followed by ethyl acetate (10 ml), water (5 ml) and formic acid (88%, 20 microliters). After approximately 30 minutes the layers are separated and the aqueous layer is extracted with ethyl acetate (2×10 ml). The organic phases are combined, washed with aqueous sodium sulfate (5 ml), dried over sodium sulfate and concentrated under reduced pressure to give a crude crystalline product.
The crude crystalline product is dissolved in acetone (5 ml) and treated with p-TSA (10 mg) at reflux for 2 hours. On cooling the mixture is diluted with water (10 ml) which gives a precipitate which is isolated and dried under reduced pressure to give the title compound. NMR (CDCl 3 ) 0.64, 1.33, 2.18, 4.97, 5.56 and 5.75 δ. ##STR1##
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The process of the present invention transforms 17-keto steroids (I) to the corresponding corticoids (IV) in three steps.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a scaffold support construction and more particularly the invention relates to a construction for engaging a concrete girder or I-beam from which a scaffolding may be suspended to provide a platform for workmen.
2. Description of the Prior Art
Reinforced concrete bridges are commonly found on today's highways and are constructed from a series of elongated generally parallel arranged girders, such as I-beams. which are supported on vertical piers at selected spaced points between each end of the bridge. The bridge deck is supported on the tops of these I-beams and is formed of reinforced concrete. These girders are formed of a generally I-shape in cross section from an I-beam or an I-beam with reinforced concrete which encloses the steel I-beam. These constructions are commonly seen throughout the country. In many situations, the concrete girder consists of a steel I-beam enclosed or encased in reinforced concrete. The concrete girder may be used for any number of construction reasons including aesthetic or weather considerations.
During bridge construction and maintenance the installation and removal of concrete forms for erecting and maintaining portions of the bridge are required to accomplish the construction steps or maintenance steps necessary. Also, it is common to paint portions of the bridge, particularly any exposed steel, as a part of the bridge's construction, initially or as a maintenance procedure periodically thereafter.
It has been a common practice over the years to erect stationary scaffolding from the ground level up to the bridge level to provide a platform for construction workers to either build or remove concrete forms or to paint portions of the bridge. In many, if not most, situations it is impractical to build scaffolding from the ground up, and in order to provide a work platform for construction workers, cables have been strung from one end of the bridge to the other across the supporting piers. Wooden planks are then placed between two adjacent cables to provide a work platform. As is readily apparent, such procedure is extremely dangerous because cable supported platforms are very unstable.
To overcome the problems inherent in the stationary scaffolding built from the ground up or the cable supported scaffolding frequently used, particularly by bridge maintenance workers, scaffold support devices have been used which are suspended from I-beam girders, commonly used in reinforced concrete bridge constructions. However, where the girder is of the reinforced concrete type, no known structure has been used or proposed to support the scaffold system from such a concrete girder.
To overcome problems inherent in either the stationary scaffold or the cable supported scaffolding devices, various types of scaffold or scaffold supporting devices have been known in the prior art. For example, U.S. Pat. No. 2,761,396 discloses a structure in which a carriage may be suspended and moved along an I-beam. This device incorporates a plurality of rollers which roll upon the top surface of the I-beam and bottom flange. These rollers are capable of being swung out of the way when an obstacle along the length of the I-beam is present. Such a device, however, can only be used between bridge piers because there is no practical way for the device to be moved past the pier between the pier and the bottom of the bridge deck when the work between two piers is completed. Furthermore, such a device is, as a practical matter, incapable of being used to support scaffolding from a concrete reinforced I-beam type girder. Thus, the device, in the case of a normal and exposed I-beam, must be disassembled and moved around a pier and reassembled for continued use. In the case of the concrete I-beam, its use, for all practical purposes, is not possible.
Other examples in the prior art include devices which render them either inconvenient or undesirable from a practical standpoint when considering the fact that scaffolding must be moved past a pier to effectively and efficiently utilize the scaffolding. For example, prior art devices are limited in terms of moving along the length of the supporting girder to those points where braces extend between adjacent girders or at those positions where two girders are spliced together by means of steel plates bolted to the abutting ends of the beams. Where cross braces extend between two girders, there is no room for the device to pass beyond the cross brace. Similarly, where these devices actually roll along the top surface of the bottom flange of an I-beam, the location where bolts, rivets and other fasteners are located to splice two beams together, movement of the rolling members past the splice plate is prevented. These devices must, therefore, be disassembled to move them past those positions on a bridge deck which normally provide structures for the movement of the scaffolding.
I am unaware of any scaffold supporting system which may be used to support scaffold members which can be used upon either exposed I-beam girders or concrete reinforced girders, and wherein the scaffold supporting roller members are located below the lower flange of either the I-beam or the concrete reinforced girder, and in which the scaffolding can be moved along the entire length of the bridge beam.
SUMMARY OF THE INVENTION
It is, therefore, a primary object of the present invention to provide a movable scaffold supporting device for engaging the lower portion of a concrete girder or an I-beam type girder so that a suspended scaffold system may be supported beneath the bridge which includes concrete girders or I-beams as the deck supporting members.
It is a further object of the present invention to provide a bridge girder engaging hangar construction which is small and lightweight and adjustable to fit various sized girders and I-beams which can be handled easily by one workman, and which can be positively locked into place and positioned at a desired location on a concrete girder or I-beam.
It is another object of the present invention to provide a concrete girder or I-beam engaging hangar construction which may be used in a simple manner and which is simple, effective and inexpensive to construct, and which provides a means of suspending scaffolding beneath a concrete girder bridge which has heretofore been impractical in the past.
It is a still further object of the present invention to provide a concrete girder or I-beam engaging hangar construction for supporting scaffolding which may be used with either exposed steel I-beams located in many portions of the country and as well as being capable of being used with a concrete bridge girder which are located in certain other areas of the country. The two different types of supporting girders are used depending upon prevailing weather conditions found in the area in which the bridge is located, and the most desirable or practical type of supporting girder is employed to meet the needs of those weather conditions.
These and other objects and advantages may be obtained by the improved scaffold supporting systems of the present invention, the general nature of which may be stated as including an elongated tubular member which supports a roller member. At one end of the tubular member, a flange engaging arm is adjustably mounted to the tubular member to accommodate various widths of girders whether they be concrete enclosed I-beam types or exposed I-beam types. The device also includes an L-shaped head member which has an extension of one of the L-legs angled to approximately duplicate the profile of a concrete bridge girder. The head member is adjustably attached to the tubular member and is reversible in position 180° so that in one position the device may engage a concrete bridge girder, or when rotated 180° may engage the flange of an I-beam.
The device also includes a spring loaded locking device which positively locks the head member against an I-beam or concrete girder and a supplementary locking device to prevent the accidental disengagement of the head member locking device. An additional locking member is provided for the adjusting means that mounts the head member to the tubular member. Further, the device includes rollers which are located beneath the bridge girder so that scaffolding may be moved along a series of hangar devices, usually three or more, from place to place along a bridge girder.
In addition, the device includes means for adjustably mounting the device upon the lower flange of exposed I-beam bridge girders. In either configuration, that is when used to engage a concrete enclosed I-beam or an exposed I-beam, the device may be easily removed from its locked position by a single workman and moved to a new location by easy manipulation of various portions of the device including the spring loaded mechanism.
When a plurality of devices are mounted upon a bridge beam of either type, the roller member that is positioned underneath the beam lower surface is capable of supporting an inverted U-shaped channel member which in turn supports a plurality of yoke arms. A second set of beam engaging members is positioned to an adjacent bridge beam to support a second inverted U-shape rail that also includes yoke arms and supporting structure extending between the lower ends of the yoke arms. When assembled in this manner, platform members may be supported by the yoke supporting members to provide a work platform for workmen to perform tasks beneath this surface of the bridge deck and in and around the beams themselves. The inverted U-rail members further include latch devices to prevent the accidental or inadvertent movement of the rails until it is desired by the workmen to reposition the device.
In actual use, after work has been completed in those areas reachable from the platform work surface, one of the hangar members may be moved to a new position on the bridge beam and the opposite hangar member similarly placed on an adjacent bridge beam. The various locked devices are then manipulated by workmen and the platform assembly and yoke members and rail are moved along the rollers to a new location and the various locking member re-engaged to securely prevent inadvertent or accidental movement of the platform. This process is continued and can be accomplished along the entire length of the supporting beam without having to engage in complicated and difficult movements of various parts associated with prior art devices.
The various members, associated with the yoke means include the yoke arms, and the yoke bottom support members are adjustable so that the height of the platform can be predetermined and the distance between the yokes can be adjusted to fit the distance between adjacent supporting beam members.
BRIEF DESCRIPTION OF THE DRAWINGS
A brief description of the invention--illustrative of the best mode in which applicant has contemplated applying the principles--is set forth in the following description and is particularly and distinctly pointed out and set forth in the appended claims.
In the drawings:
Fig. 1 is a top plan view, with portions broken away, of the beam engaging member of the present invention;
FIG. 2 is a side elevation of the engaging member of the present invention shown in the position as it engages a concrete enclosed I-beam;
FIG. 3 is a side elevation showing portions of the locking means taken along the lines 3--3, FIG. 2;
FIG. 4 is a perspective view of the adjusting flange engaging member which forms a portion of the present invention;
FIG. 5 is a perspective view of the member which supports the roller structure to the tubular hangar member;
FIG. 6 is a view similar to FIG. 2 in section showing the spring loaded locking mechanism;
FIG. 7 is a view similar to FIG. 6 showing the device in unlocked position so that the hangar member may be removed from its locked supporting position shown in FIGS. 2 and 6;
FIG. 8 is a cut-away portion of the hangar tubular member illustrating in plan view portions of the locking and adjusting member;
FIG. 9 is a view, taken on the lines 9--9 of FIG. 7 illustrating the supplementary locking mechanism which prevents disengagement of the device when in engaged position shown in FIGS. 2 and 6;
FIG. 10 is a view similar to FIG. 2 illustrating the device as it engages an exposed I-beam type girder;
FIG. 11 is a diagrammatic view illustrating how the device is moved in "leap frog" fashion along a bridge beam to facilitate access to all areas under and adjacent to the scaffold; and
FIGS. 12--14 are diagrammatic view similar to FIG. 11 which illustrate further steps in the procedure of moving the hangers and scaffold system along a bridge beam.
Similar numerals refer to similar parts in the various figures of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The hanger support of the present invention includes an elongated tubular member 20 having a carrier block 22 slidably mounted therein. Block 22 is spring biased by spring 24 which extends between block 22 and a spring retainer pin 26. One end of spring 24 is attached to pin 26 and the other end is attached to ear 28 of block 22. Block 22 is urged toward pin 26 by spring 24 when moved away from pin 26.
A pair of threaded rods 30 are threaded in and carried by block 22 and extend through elongated slots 32a and 32b formed in the upper face 34 and lower face 36 of elongated tube 20. The device also includes a beam engaging head member 40 which is mounted to rods 30 and adjustably secured by nuts 42. Head member 40 is L-shaped and includes a steel beam engaging end 46. Head member 40 is adjustably mounted on rods 30 either toward or away from tube 20 by movement of nuts 42. To prevent movement of head 40 a lock pin 48 is removably placed in holes formed through the upper end of rods 30. Nuts 42 are tightened to maintain head 40 at the desired position relative to tube 20 and in correct adjustment to engage a beam of a bridge.
The device also includes roller carriage member 50 formed in open ended box configuration with one end 50a attached to tube 20 by welding. Lower end 50b extends below tube 20 and carries a roller support arm 52 which is attached thereto by bolt assembly 54. Roller support arm 52 includes a horizontal support roller 56 and a guide roller 58 for guiding and supporting the scaffold system, as will be described below.
The device also includes an adjustable beam engaging arm 60 which is attached to the inner end 62 of tube 22 and movable along the top face of tube 20 so that when the device engages a bridge beam the device is maintained in position. This is done by bolt 64 which is mounted in holes 64a formed in dovetail portion 66 of arm 60. Arm 60 is maintianed in position on tube 20 by clamping bracket 68.
Block 22 is slidable within tube 20 and controls engagement of head 40 with a bridge beam. A locking system which is included in the system will now be described. The The locking system includes a locking pin 70 having one end attached to block 22 and the other end extending through a keyhole shaped aperture 72 formed in end plate 73 of tube 20. Pin 70 includes a shoulder 74 which is larger than one portion of keyhole 72 but smaller than the second portion. A smaller diameter portion 70a of pin 70 extends through keyhole 72 and has connected thereto a handle portion 75. In locked position, as shown in FIG. 2 and 6, head 40 engages one portion of a beam and arm 60, which has been adjusted into position, and engages the opposite portion of a bridge beam. Movement of block 22 and therefor head 40 is prevented by shoulder 74 engaging end plate 73 which prevents movement of block 22. A latch member 76 prevents pin 70 and shoulder 74 from being moved upwardly in slot 72 to disengage shoulder 74 from engagement with end plate 73.
To disengage head 40 from a beam, latch 76 is disengaged and pin portion 70a is moved upwardly to the position shown in FIG. 9 and allows shoulder 74 to pass through keyhole aperture 72. This allows sliding movement of block 22 in tube 20 away from pin 26 and therefor the bridge beam. Movement of block 22 can be accomplished by manual manipulation by pulling one of threaded rods 30 against spring bias exerted by spring 24.
The device is, therefore, engageable on a bridge beam by sliding block 22 manually inwardly and outwardly within tube 22 to allow head 40 and arm 60 to engage the opposite flanges of the beam. In the case of a concrete enclosed beam, the head member is oriented into the position shown in FIGS. 2 and 6 for engagement with the profile of a beam. If the bridge beam is of the unenclosed steel type, the head 40 is rotated 180° to the position shown in FIG. 20 so that head member 40 will engage the flange of the bridge, as shown in FIG. 10.
When the device is locked in the position shown in FIGS. 6 or 10, it is in position to support a scaffolding member, as shown in FIG. 2. The scaffolding member includes an inverted U-shaped channel member which is supported on rollers 56. The channel 80 will carry the yoke member 82 which hangs downwardly from inverted U-channel 80. In actual practice a plurality of hanger members are attached along one side of a bridge beam, as shown in FIGS. 11 through 14. A similar and oppositely oriented plurality of hanger members will be located at the next adjacent beam of the bridge which will support a similar U-shaped channel member 80 and a pair of yoke members 82. A scaffolding platform is carried by yokes 82 and extends between the two adjacent beam support constructions.
The manner of use of the system of the present invention is illustrated diagrammatically in FIGS. 11 through 14. In these views, one set of hangers on one side of the scaffolding is illustrated and it is to be understood that a similar but oppositely oriented set will be disposed along the next adjacent bridge beam with the scaffolding platform being supported by the yoke members of each and extending between the two sets of hangers and yoke members. When the workmen are finished working on a portion of the bridge, the hanger system will be as illustrated in FIG. 11. To proceed along the bridge beams to reposition the scaffolding so that the workmen may work on a different area, it will be necessary to move the scaffolding to reposition it so that the workmen have access to this new area. One of the plurality of hangers will be located at position D, as illustrated in FIG. 12. The inverted U-shaped track 80 is moved by rolling it along supporting rollers 56 in the direction of the arrow of FIG. 12. As can be appreciated from FIG. 12, the channel support 80 is initially supported by three hangers A, B and C, and as it is moved toward hanger D it will again be supported by three hangers, this time hangers B, C and D. Further movement of the hanger is prevented by stop member 82 which engages hanger A to stop further movement. Latch 82 must be manually disengaged by the workmen to allow continued movement. At this point hanger A is removed from the beam by disengaging the lock means on the hanger support and pulling the head member 40 away from the flange of the bridge and repositioning it, as in FIG. 14. Continued movement of the scaffolding along the bridge beam from one position to another is accomplished by repeated movement of the plurality of hangers which engage the two adjacent beams from one end of the beam to the other.
An important aspect of the invention, and as can be seen in FIG. 2, is that the entire scaffold system and most of the hangers are positioned below the bottom of the beam flange so that any obstruction on the top of the flange of the beam or extending between the beams will not interfere with movement of the system along the beams. Furthermore, another important aspect of the invention is the fact that the scaffold system is always supported by three hanger members on each side so long as the workmen correctly position the hangers as they are moving the hangers in leap-frog fashion.
This provides a high degree of safety for the workmen who will be working from the scaffold platform hanging below the bridge beam. A further advantage is provided by the fact that the simple movement of one hanger to a new position is all that is necessary to permit movement of the scaffold in a system as work progresses along the length of the beam. This is in contrast to those systems which roll on the top flange of the bridge beam, where obstructions such as splice plates or cross beam members would interfere with the movement of a hanger system that rolls on the top of the flange of the bridge beam.
In the foregoing description, certain terms have been used for brevity, clearness and understanding but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed.
Moreover, the description and illustration of the invention is by way of example, and the scope of the invention is not limited to the exact details of the construction shown or described.
Having now described the features, discoveries and principles of the invention, the manner in which the improved scaffold hanger construction is constructed, assembled and operated, the characteristics of the new construction, and the advantageous, new and useful results obtained; the new and useful structures, devices, elements, arrangements, parts and combinations are set forth in the appended claims.
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A movable scaffold supporting device, for engaging the lower portion of a concrete girder or an I-beam type girder, including an elongated tubular member, an adjustable flange engaging arm mounted to the tubular member, an L-shaped head member, a spring loaded locking device which positively locks the head member against an I-beam or concrete girder, and a supplementary locking device. Further, the device includes rollers located beneath the bridge.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 11/330,757 filed Jan. 12, 2006 which claims the benefit of an earlier filing date from U.S. Provisional Application Ser. No. 60/643,819 filed Jan. 14, 2005, the entire disclosure of each of which is incorporated herein by reference.
BACKGROUND
In oil and gas wells, multi-pathway tubes around screen shrouds are known to convey gravel pack slurry beyond annular obstructions of any kind. In general, such multi-pathway tubes (also termed alternate path technology) begin “operating” automatically when an obstruction such as an annular bridge arises. Multi-pathway tubes are open to the annulus just downstream of a gravel pack packer and provide an alternate path for the flow of the slurry if indeed gravel slurry pressure rises due to an annular obstruction. Where no annular obstruction exists, the multi-pathway tube is naturally bypassed for the easier flowing annulus.
Where the multi-pathway tube does become a slurry conduit, that slurry is reintroduced to the annulus downstream of the obstruction by exiting ports in the multi-pathway tube where pressure in the annulus allows. Because of the high pressure in the multi-pathway tube, the slurry tends to exit at a high velocity. Slurry being by nature erosive, a property exacerbated by high velocity, it is a very effective cutting implement. Any type of control line utilized must be protected from this discharge.
In order to run control lines downhole, the art has clamped the lines to outside of the screen shroud, and run an additional screen shroud outside of the multi-pathway tubes. This may be effective but does increase the overall outside dimension of the assembly. As one of skill in the art is all too aware, increasing an outside dimension or reducing an inside dimension are to be avoided.
SUMMARY
A gravel pack multi-pathway tube includes a body; a gravel slurry flow passage defined by the body; and a projection at the body, the projection extending laterally from the body relative to an extent of the flow passage, the projection defining an area, that is protected from a lateral impact, a direction of the impact being defined by a set of force vectors and where a radial vector is the largest of the set of vectors, the radial vector intersecting a control line protected by the projection.
A gravel packing device component includes a shroud; a multi-pathway tube at the shroud; and a projection extending laterally from the multi-pathway tube to create a protected space between the projection and the shroud, the space being protected from a lateral impact including a force vector substantially radially directed relative to the shroud the space being receptive to a control line.
A unitary gravel pack multi-pathway tube includes a body; a gravel slurry flow passage defined within the body; and a control line protection projection extending from and supported by the body, the projection extending laterally from the body relative to an extent of the flow passage.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings wherein like elements are numbered alike in the several Figures:
FIG. 1 is a perspective schematic view of a gravel pack component illustrating multi-pathway tubes and a control line;
FIG. 2 is a cross-sectional view of the multi-pathway tube with a screen shroud shown in phantom;
FIG. 3 is a schematic elevation view of the component illustrated in FIG. 1 entering a rotary and the control line being inserted;
FIG. 4 is a view similar to FIG. 2 but with one of the projections bent;
FIG. 5 is a schematic representation of an alternative multi-pathway tube; and
FIG. 6 is a schematic representation of the alternative multi-pathway tube of FIG. 5 in a completed condition.
DETAILED DESCRIPTION
Referring to FIG. 1 , some of the components of a gravel packing apparatus 10 are illustrated to provide environment for the arrangement disclosed herein. In FIG. 1 , a cross coupling connector 12 is illustrated twice with a space interval. The space interval is occupied primarily by a gravel pack screen. Such screens are known to the art and do not require explanation here. The screen itself is not shown in the figures hereof but will be understood by one of ordinary skill in the art to be beneath the screen shroud (identified as 42 hereunder), which is represented in the figures. Although the view includes only two connectors 12 , it is to be understood that more (or only one) may be utilized in the gravel pack apparatus 10 . Each connector 12 is illustrated with pass-through 14 for four multi-pathway tubes 16 a . The tubes 16 a proceed longitudinally and meet in a fluid conveyable manner with multi-pathway tubes 16 b . Multi-pathway tubes 16 b proceed helically along apparatus 10 until meeting in a fluid conveyable manner with multi-pathway tubes 16 c . Multi-pathway tubes 16 c proceed longitudinally into the next connector 12 . It will be understood that tubes 16 a - c are each considered a multi-pathway tube and are broken into parts merely to aid discussion. As noted, four multi-pathway tubes 16 a - c are illustrated; it is to be understood that more or fewer can be utilized as desired.
At each connector 12 , at least one of the multi-pathway tubes 16 a - c will have ports (not shown but known to one of skill in the art and present in the commercially available “direct pak” screen from Baker Oil Tools, Houston, Tex.). Multi-pathway tubes adjacent those with ports will not have ports. A particular tube will have ports for about one-quarter of the total length of the screen component (see screen shroud 42 ) of the gravel pack apparatus 10 . For example, a 1000-foot screen will have the ports change four times, once at each 250-foot increment of the 1000-foot screen. Each change will occur at a cross coupling connector 12 . The fact that one of the tubes 16 a - c will not have ports at each increment means that such tube may safely retain a control line 18 in an appurtenant projection (specifically identified hereunder). To maintain the control line in safety along the entirety of the screen section, the line may be moved back and forth between adjacent appurtenant projections at the end of each increment, with the change taking place at a connector 12 . As is apparent from the foregoing, a desired location for the control line is along one of the tubes 16 b that does not have ports. Utilizing this arrangement, a control line may be secured in a position that is not particularly exposed to the high velocity gravel slurry while also avoiding the need for any external clamps or extra shroud. Further, because of the ability of the control line to be shifted back and forth between adjacent tubes 16 a - c , the control line may be kept away from the high velocity slurry over the entire extent of the screen section (see screen shroud 42 ) of apparatus 10 .
Because of the arrangement noted, the inventors hereof determined that securement of the control line near a multi-pathway tube that did not include ports for each of the segments of the apparatus would be advantageous. Unfortunately, there was no known way to achieve this without resorting to external clamps, which suffer from the drawbacks noted above. Referring to FIG. 2 , a cross-section view of a multi-pathway tube 16 b according to the teaching herein is illustrated. Tube 16 b includes a body 30 defining a flow passage 32 , the body having a radially larger boundary 60 and a radially smaller boundary 62 , the boundaries joined laterally by semicircular boundaries 64 . Further, appurtenant the body 30 is at least one, and as illustrated two, wing-shaped projections 34 . Each projection 34 extends from body 30 , at a substantially equivalent radius of curvature to the radially larger boundary 60 , at a lateral edge thereof and extends for a length sufficient to receive a control line (not shown). Each projection forms a pocket 36 between a concave surface 38 thereof and an outer surface 40 (shown in phantom) of screen shroud 42 (see FIG. 1 ). Advantageously, projection 34 includes a lip 44 at an end thereof remote from body 30 . Lip 44 is useful for enhancing retention of control line 18 once inserted at projection 34 . Further, lip 44 causes an outside surface 46 of projection 34 to present a convex configuration, which is helpful with respect to avoiding hang-ups during the running of the apparatus 10 .
As noted above, tube 16 b is helically arranged about shroud 42 , which additionally assists in maintaining the control line 18 against the shroud 42 .
Referring to FIG. 3 , a schematic representation depicting shroud 42 , tube 16 b , control line 18 and an insertion device is provided. A rotary table 50 is known to the art and requires no explanation. Extending from a portion of the table 50 is a support 52 upon which is mounted a cable snap machine 54 . The cable snap machine 54 is here illustrated to comprise a body 56 and four rolling or non-rolling bushings 58 . It is to be understood that more or fewer bushings could be utilized and that bearings could be substituted without departing from the scope of the disclosure hereof. The bushings 58 that are horizontally (in the figure) spaced from each other are a fixed distance apart, that distance calculated to support the tube 16 b at one side and urge the control line 18 under the projection 34 on the other side of the same tube 16 b . Movement of the shroud (and the rest of the apparatus 10 ) in a downward direction (relative to the figure) automatically causes the control line to engage the projection 34 . The second pair of bushings illustrated lower in the figure either further engage the control line with the projection or merely ensure that it engaged appropriately when passing through the first set of bushings. Additionally, in one embodiment, if one of the wing-shaped projections 34 at the multi-pathway tube does not contain a control line, the snap machine may be configured to deform the unsupported projection inwards toward the screen shroud 42 to reduce the possibility of the unsupported projection 34 coming in contact with any restrictions in the wellbore, which may potentially damage the flow area section of the tube. Such a condition is illustrated in FIG. 4 . The deforming of the projection can be accomplished simultaneously while the control line is being snapped into the other side of the tube or can be accomplished without regard for whether or not a control line is present on the other side of the tube 16 b.
In yet another embodiment, referring to FIGS. 5 and 6 , the projection 34 (here illustrated to be welded at weld bead 70 onto the multi-pathway tube 16 b ) is deformed over an inserted control line by bending lip 44 toward the shroud 42 to more permanently and encapsulatively engage the control line. The lip is illustrated in the undeformed condition in FIG. 5 and in the deformed condition in FIG. 6 . The snap in machine is easily modifiable to accomplish the deforming of the projection to encapsulate the control lines against the shroud 42 by substituting a differently shaped bushing or bearing having a concave shape to form the lip 44 .
Earlier in this disclosure, it was stated that the control line is maintained in a protected position relative to ports in the multi-pathway tubes 16 b . When inserting the control line into the tube 16 b , and after a one-quarter length of the total gravel screen is reached the control line is manually moved over to position it to be engaged by an adjacent tube 16 b . The process of inserting the control line 18 then continues as described hereinabove. One of skill in the art should appreciate that when the line 18 is moved over to an adjacent tube 16 b , the line will be on a physically opposite side of the machine 54 . In an embodiment where each side of machine 54 is a mirror image, no adjustment will be necessary but only a reengagement with the control line need be performed. Alternatively, and where one of the described embodiments that causes deformation is utilized, the machine 54 will be adjusted to reverse the action of the machine such as by reversing the bushings 58 .
In accordance with the concepts and apparatus disclosed herein, control lines hereby can be added to the apparatus 10 right on the rig floor and while the apparatus is being run in the hole. Resultantly, the control line is protected and maintained in position. It is to be understood that “control line” as used herein is intended to include single or multiple hydraulic, electrical, fiber optic lines, etc. and that the lines may be individual in form, nested, flat packed, etc.
While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
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A unitary gravel pack multi-pathway tube includes a body; a gravel slurry flow passage defined within the body; and a control line protection projection extending from and supported by the body, the projection extending laterally from the body relative to an extent of the flow passage and method.
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TECHNICAL FIELD
The present invention relates to a micro base station apparatus and a method of assigning subbands.
BACKGROUND ART
Recently, micro base station apparatuses (home base station: Home eNB, hereinafter HeNB) to form small cells have been developed for complementing dead zones of mobile phone networks. The small cell is referred to as a femto cell, covering a smaller communication area than one conventional cell. Conventional large base station apparatuses to form cells having large communication areas (Macro base station: Macro eNB, hereinafter referred to as an MeNB) are set beforehand through an appropriate design of placement of stations by operators. Interference between cells does not make a significant problem owing to an ICIC (Inter Cell Interference Coordination) control function between the MeNBs. In contrast with this, end users can set HeNBs in any place and there is no ICIC control function between the HeNB and the MeNB. Interference between the HeNB and the MeNB therefore makes a significant problem in HeNB. Especially, the placement of the HeNB should not interfere with the communications of any existing MeNB. This is because the MeNB is used for forming an existing communication area, for example, for mobile phone networks, and it is necessary to avoid inconvenience such as sudden disconnection of the mobile phones caused by a newly placed HeNB.
With LTE (Long Term Evolution) which has been standardized by international standards organization 3GPP (3rd Generation Partnership Project), subbands allocated to the HeNB are scheduled in a frequency band (including a plurality of subbands) available for the HeNB (see, for example, Non-patent Literature 1). The HeNB assigns subbands based on the resulting schedule and communicates with a communication terminal apparatus (hereinafter, referred to as HUE: Home UE) connected to the HeNB.
With LTE, MeNBs (surrounding MeNBs) are connected to each other by an X2 interface. Each eNB (an MeNB and an HeMB), and an MME (Mobility Management Entity)/S-GW (Serving Gateway) or an HeNB GW are connected by an S1 interface (see, for example, Non-Patent Literature 2). By contrast with this, LTE has no interface directly connecting the MeNB and the HeNB.
CITATION LIST
Non-Patent Literature
NPL 1
R4-093651 “Intercell interference management for HeNBs”(ETRI)
NPL 2
3GPP TS 36.300 v9.2.0, “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2”
SUMMARY OF INVENTION
Technical Problem
In the above conventional technique, subbands assigned to the HeNB through scheduling are fixed (the same subband) over a plurality of frames. When the MeNB and the HeNB exchange no control information at this time, the MeNB may assign the same subband as the subband allocated to the HeNB, to a communication terminal apparatus connected to the MeNB (hereinafter referred to as an MUE: Macro UE). That is to say, subbands used in the MeNB and the HeNB may overlap.
In this case, when the MUE receives downlink signals (desired signals) from the MeNB, the MUE may receive interference due to signals transmitted from the HeNB to the HUE in downlink. Also, when the MeNB receives uplink signals (desired signals) from the MUE, the MeNB may receive interference due to signals transmitted from an HUE located in the vicinity of the MeNB to the HeNB in uplink. In view of the above, the communications of the HeNB may interfere with the existing communications of the MeNB.
When the HeNB receives uplink signals (desired signals) from the HUE, the HeNB may receive interference due to signals transmitted from an MUE located in the vicinity of the HeNB to the MeNB in uplink. When the HUE receives downlink signals (desired signals) from the HeNB, the HUE may receive interference due to signals transmitted from the MeNB to the MUE in downlink. That is to say, the communications of the MeNB may interfere with the communications of the HeNB.
Here, the exchange of control information (for example, information indicating used MeNB subbands) between the MeNB and the HeNB prevents subbands used between the MeNB and the HeNB from overlapping. However, there is no interface that directly connects the MeNB with the HeNB, as described above. Furthermore, when the MeNB and the HeNB exchange information using an Si interface, the information need to be transmitted through other devices (for example, MME/S-GW), so that the delay of a process occurs.
It is an object of the present invention to provide a micro base station apparatus and a subband assigning method that can suppress interference between an HeNB and an MeNB without exchanging information between the MeNB and the HeNB.
Solution to Problem
A micro base station apparatus according to the first aspect of the present invention is a micro base station apparatus forming a smaller cell than a cell formed by a macro base station apparatus, and employs a configuration including: a generation section that generates an assigning pattern of subbands assigned to the micro base station apparatus among a plurality of subbands available for the micro base station apparatus, the assigning pattern having a subband combination which varies every predetermined time interval; and an assignment section that assigns the subbands to a communication terminal apparatus connected to the micro base station apparatus, based on the assigning pattern.
A method for assigning subbands according to the second aspect of the present invention is a method for assigning subbands in a micro base station apparatus forming a smaller cell than a cell formed by a macro base station apparatus, and employs a configuration including the steps of: generating an assigning pattern of subbands assigned to the micro base station apparatus among a plurality of subbands available for the micro base station apparatus, the assigning pattern having a subband combination which varies every predetermined time interval; and assigning the subbands to a communication terminal apparatus connected to the micro base station apparatus based on the assigning pattern.
Advantageous Effects of Invention
According to the present invention, it is possible to suppress interference between an HeNB and an MeNB without exchanging information between the MeNB and the HeNB.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a block diagram showing a configuration of an HeNB according to Embodiment 1 of the present invention;
FIG. 2 is a drawing showing an assigning pattern according to Embodiment 1 of the present invention;
FIG. 3 is a drawing showing an assigning pattern according to Embodiment 1 of the present invention;
FIG. 4 is a drawing showing an assigning pattern according to Embodiment 1 of the present invention;
FIG. 5 is a block diagram showing a configuration of an HeNB according to Embodiment 2 of the present invention;
FIG. 6 is a drawing showing an assigning pattern according to Embodiment 2 of the present invention;
FIG. 7 is a drawing showing an assigning pattern according to Embodiment 2 of the present invention;
FIG. 8 is a block diagram showing a configuration of an HeNB according to Embodiment 3 of the present invention;
FIG. 9 is a drawing showing an assigning pattern according to Embodiment 3 of the present invention;
FIG. 10 is a drawing showing an assigning pattern according to Embodiment 3 of the present invention;
FIG. 11 is a drawing showing an assigning pattern according to Embodiment 4 of the present invention;
FIG. 12 is a drawing showing an assigning pattern according to Embodiment 4 of the present invention;
FIG. 13 is a block diagram showing an HeNB according to Embodiment 5 of the present invention;
FIG. 14 is a drawing showing an assigning pattern in discontinuous subbands; and
FIG. 15 is a drawing showing an assigning pattern in discontinuous subbands.
DESCRIPTION OF EMBODIMENTS
Embodiments according to the present invention will be described below in detail with reference to the drawings. In the following explanation, embodiments will be described using an LTE as an example,
(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of an HeNB forming a smaller cell than one formed by an MeNB. In HeNB 100 shown in FIG. 1 , pattern generating section 101 receives as input information showing the number of subbands used by HeNB 100 (the number of used subbands) and a total number of subbands available for HeNB 100 . Pattern generating section 101 then generates an assigning pattern of subbands assigned to HeNB 100 (and an HUE), based on the number of used subbands and the total number of subbands. Specifically, pattern generating section 101 selects subbands assigned to HeNB 100 (an HUE) (the number of used subbands) from among a plurality of subbands available for HeNB 100 (the total number of subbands), and generates an assigning pattern including the selected subbands. Pattern generating section 101 generates an assigning pattern having a subband combination which varies every predetermined time interval (one frame in the present embodiment). The predetermined time interval is not limited to one frame, and may be a plurality of frames (this is the same as in the following embodiments).
Assignment section 102 assigns subbands to an HUE based on the assigning pattern inputted from pattern generating section 101 .
Notification section 103 notifies an HUE connected to HeNB 100 of notification information showing subband assignment result in assignment section 102 .
Details of a process in HeNB 100 will be then described.
In the following description, subbands available for HeNB 100 are defined to be subbands 1 to 12 (subband total number: 12) as shown in FIG. 2 . Subbands used for HeNB 100 in each frame are assumed to be four (the number of used subbands: 4). As shown in FIG. 2 , MUEs are assigned to three subbands 6 to 8 over a plurality of frames.
Pattern generating section 101 generates an assigning pattern of subbands assigned to HeNB 100 (Here, four subbands) among twelve subbands 1 to 12 shown in FIG. 2 , every frame. At this time, pattern generating section 101 generates an assigning pattern having a subband combination which varies every frame. Pattern generating section 101 randomly selects four subbands from subbands 1 to 12 shown in FIG. 2 every frame, thereby generating an assigning pattern having a subband combination which varies every frame, for example.
In frame 1 shown in FIG. 2 , pattern generating section 101 , for example, generates an assigning pattern including a combination of subbands 2 , 6 , 7 , and 11 . As shown in FIG. 2 , pattern generating section 101 also generates an assigning pattern including a combination of subbands 2 , 4 , 10 , and 12 in frame 2 , an assigning pattern including subbands 1 , 3 , 5 , and 9 in frame 3 , an assigning pattern including subbands 2 , 3 , 8 , and 11 in frame 4 .
Here, it is assumed that HUE 1 and HUE 2 are connected to HeNB 100 . As shown in FIG. 3 , assignment section 102 assigns subbands to each of HUE 1 and HUE 2 based on the assigning pattern shown in FIG. 2 . In frame 1 shown in FIG. 3 , assignment section 102 assigns subbands 6 and 11 to HUE 1 , and assigns subbands 2 and 7 to HUE 2 among subbands 2 , 6 , 7 , and 11 shown in the assigning pattern, for example. In frame 2 shown in FIG. 3 , assignment section 102 similarly assigns subbands 4 and 12 to HUE 1 , and assigns subbands 2 and 10 to HUE 2 among subbands 2 , 4 , 10 , and 12 shown in the assigning pattern. In frame 3 and frame 4 shown in FIG. 3 , assignment section 102 assigns subbands in the same manner as the above.
Pattern generating section 101 and assignment section 102 perform the same process as the above on frames other than frames 1 to 4 (frame 5 and thereafter, not shown).
Then, notification section 103 notifies HUE 1 and HUE 2 of notification information showing a subband assignment result shown in FIG. 3 .
In view of the above, even if the same subband is assigned to the HUE and the MUE in a frame (for example, frame 1 shown in FIG. 3 ), varying a subband combination included in a subband assigning pattern every frame reduces the probability that the same subband is assigned to the HUE and the MUE in the next frame (for example, frame 2 shown in FIG. 3 ). That is to say, each subband (subbands 1 to 12 shown in FIG. 3 ) is equally assigned to HeNB 100 , so that the probability that subbands used for HeNB 100 and the MeNB overlap over a plurality of frames is reduced.
Accordingly, the above process reduces the probability that signals transmitted from an HeNB to the HUE in downlink interfere with the MUE when the MUE receives downlink signals (desired signals) from the MeNB, for example. Moreover, the above process reduces the probability that signals transmitted from the MeNB to the MUE in downlink interfere with the HUE when the HUE receives downlink signals (desired signals) from the HeNB.
Next, as shown in FIG. 4 , a case will be described where an MeNB is assigned to three subbands 6 to 8 over a plurality of frames as with FIG. 3 . In FIG. 4 , pattern generating section 101 of HeNB 100 generates the assigning pattern shown in FIG. 2 and assignment section 102 assigns subbands to UEs based on the assigning pattern shown in FIG. 2 .
In FIG. 4 as well, the above process reduces the probability that signals transmitted from an HUE located in the vicinity of the MeNB to the HeNB in uplink interfere with the MeNB over a plurality of frames when the MeNB receives uplink signals (desired signals) from the MUE, for example. The above process reduces the probability that signals transmitted from an MUE located in the vicinity of the HeNB to the MeNB in uplink interfere with the HeNB over a plurality of frames when the HeNB receives uplink signals (desired signals) from the HUE.
That is to say, varying a subband combination included in a subband assigning pattern, every frame can randomize (average) interference between the MeNB (MUE) and the HeNB (HUE) as shown in FIG. 3 and FIG. 4 . This makes it possible to reduce the probability that the communications of HeNB 100 interfere with the communications of an existing MeNB and to reduce the probability that the communications of the MeNB interfere with the communications of HeNB 100 .
HeNB 100 also generates a subband assigning pattern based on only a total number of subbands available for HeNB 100 and the number of used subbands for HeNB 100 . That is to say, HeNB 100 can generate a subband assigning pattern without exchanging information (for example, information showing the used MeNB subbands) with the MeNB.
According to the present embodiment, it is possible to suppress interference between an HeNB and an MeNB without exchanging information between the MeNB and the HeNB.
(Embodiment 2)
FIG. 5 is a block diagram showing a configuration of an HeNB according to the present embodiment. Here, in FIG. 5 , the same components as in FIG. 1 will be assigned the same reference numerals, and overlapping descriptions will be omitted.
In HeNB 200 according to the present embodiment shown in FIG. 5 , detection section 201 detects signals from an MUE (uplink signals transmitted from the MUE to an MeNB) from signals received in the reception section of HeNB 200 (not shown).
Specification section 202 specifies subbands (positions and the number of subbands) to which signals from the MUE are assigned among a plurality of subbands, using the signals detected in detection section 201 . Specification section 202 , for example, specifies subbands to which signals having lager power than a preset threshold are assigned among the signals detected in detection section 201 . In other words, specification section 202 specifies the subbands (interference bands) which may interfere with HeNB 200 (or the HUE). Specification section 202 then outputs subband information showing the specified subbands to pattern generating section 203 .
Pattern generating section 203 generates an assigning pattern of subbands assigned to HeNB 200 (and the HUE) based on the number of used subbands of HeNB 200 and the subband information inputted from specification section 202 . Specifically, pattern generating section 203 selects subbands assigned by HeNB 200 to the HUE, in subbands other than subbands to which signals from the MUE are assigned (interference bands), from among a plurality of subbands available for HeNB 200 , and generates an assigning pattern including the selected subbands (subbands assigned to the HUE).
Next, a process in HeNB 200 according to the present embodiment will be described in detail.
In the following description, subbands available for HeNB 200 are assumed to be subbands 1 to 12 (subband total number: 12) as shown in FIG. 6 as with Embodiment 1. Subbands used for HeNB 200 in each frame are assumed to be four (the number of used subbands: 4) as with Embodiment 1.
In FIG. 6 , specification section 202 specifies three subbands 6 to 8 as subbands (interference bands) to which signals having lager power than a preset threshold are assigned, among the signals from the MUE detected in detection section 201 .
Pattern generating section 203 generates an assigning pattern of subbands (four subbands) assigned to HeNB 100 in subbands (subbands 1 to 5 and subbands 9 to 12 ) other than subbands 6 to 8 (interference bands) specified in specification section 202 , among twelve subbands 1 to 12 shown in FIG. 6 .
Pattern generating section 203 , for example, generates an assigning pattern including a combination of subbands 2 , 4 , 9 , and 11 among subbands 1 to 5 and subbands 9 to 12 (subbands other than subbands 6 to 8 ) as shown in FIG. 6 .
Here, HUE 1 and HUE 2 are assumed to be connected to HeNB 200 as with Embodiment 1 ( FIG. 3 ). Assignment section 102 assigns subbands 4 and 11 to HUE 1 , and assigns subbands 2 and 9 to HUE 2 among subbands 2 , 4 , 9 , and 11 shown in the assigning pattern, as shown in FIG. 6 .
In view of the above, HeNB 200 generates a subband assigning pattern to the HUE in subbands other than subbands to which signals which may interfere with HeNB 200 (HUE) (signals from an MUE) are assigned. That is to say, HeNB 200 does not assign subbands to which signals having a possibility of interfering with HeNB 200 (HUE) are assigned, to the HUE.
By this means, HeNB 200 (HUE) and the MUE which may interfere with HeNB 200 are not assigned to the same subband over all frames. Accordingly, in FIG. 6 , signals transmitted from the HeNB to the HUE in downlink do not interfere with the MUE when the MUE receives downlink signals (desired signals) from the MeNB, for example. Moreover, signals transmitted from the MeNB to the MUE in downlink do not interfere with the HUE when the HUE receives downlink signals (desired signals) from the HeNB.
Similarly, even when the MeNB is assigned to three subbands 6 to 8 over a plurality of frames instead of the MUE shown in FIG. 4 (not shown), for example, signals transmitted from the HUE located in the vicinity of an MeNB to the HeNB in uplink do not interfere with the MeNB when the MeNB receives uplink signals (desired signals) from the MUE. Moreover, signals transmitted from an MUE located in the vicinity of the HeNB to the MeNB in uplink do not interfere with the HeNB when the HeNB receives signals (desired signals) from the HUE.
HeNB 200 also generates a subband assigning pattern based on only the signals from an MUE, which are detected in detection section 201 , a total number of subbands available for HeNB 200 , and the number of used subbands of HeNB 200 . That is to say, HeNB 200 can generate a subband assigning pattern without exchanging information (for example, information showing the used MeNB subbands) with the MeNB, as with Embodiment 1.
In view of the above, according to the present embodiment, it is possible to suppress interference between an HeNB and an MeNB without exchanging information between the MeNB and the HeNB as with Embodiment 1.
In the present embodiment, a case has been described where pattern generating section 203 in HeNB 200 employs the same subband combination included in the subband assigning pattern every frame. Pattern generating section 203 may vary a subband combination included in the assigning pattern every frame by combining the present embodiment with Embodiment 1. For example, pattern generating section 203 randomly selects four subbands every frame in subbands (subbands 1 to 5 and subbands 9 to 12 ) other than subbands 6 to 8 (interference bands) specified in specification section 202 from among twelve subbands 1 to 12 , as shown in FIG. 7 , thereby generating an assigning pattern having a subband combination which varies every frame.
This makes it possible to avoid assigning a subband to HeNB 200 (HUE) in interference bands (subbands 6 to 8 in FIG. 7 ) and prevent HeNB 200 (HUE) from receiving interference from the MUE (an MUE for which signals are assigned to subbands having higher received signal power than a threshold). Furthermore, employing the assigning pattern having a subband combination which varies every frame as with Embodiment 1 in subbands other than the interference bands can randomize (average) interference between other MUEs (MUEs for which signals are assigned to subbands having received signal power equal to or less than a threshold) and HeNB 200 , and suppress interference between the MeNB and HeNB 200 .
(Embodiment 3)
FIG. 8 is a block diagram showing a configuration of an HeNB according to the present embodiment. Here, in FIG. 8 , the same components as in FIG. 5 will be assigned the same reference numerals, and overlapping descriptions will be omitted.
In HeNB 300 according to the present embodiment, specification section 301 specifies subbands (positions and the number of subbands) to which signals from an MUE are assigned among a plurality of subbands, using the signals detected in detection section 201 , as with specification section 202 in Embodiment 2. Furthermore, specification section 301 specifies received signal power (that is to say, interference power) in subbands to which signals from the MUE are assigned.
Subband number determination section 302 first classifies a plurality of subbands available for HeNB 300 into a plurality of subband groups according to the level of the specified received signal power in specification section 301 . That is to say, subband number determination section 302 groups the plurality of subbands available for HeNB 300 into subband groups including subbands having the same degree of received signal power. Subband number determination section 302 then determines the number of subbands used for an assigning pattern every subband group such that HeNB 300 is assigned to subband groups having lower received signal power. Here, a total number of subbands determined in each subband group is the number of used subbands of HeNB 300 .
Pattern generating section 303 generates an assigning pattern of subbands assigned to HeNB 300 (and an HUE) based on the number of subbands determined in subband number determination section 302 . Specifically, pattern generating section 303 generates the assigning pattern of subbands by extracting the number of subbands determined in each subband group in subband number determination section 302 from subbands in each subband group. That is to say, pattern generating section 303 generates the subband assigning pattern such that a larger number of subbands forming a subband group having lower received signal power are assigned to HeNB 300 , among the plurality of subband groups resulting from the classification according to the level of received signal power.
Next, a process in HeNB 300 according to the present embodiment will be described in detail.
In the following description, subbands available for HeNB 300 are assumed to be subbands 1 to 12 (subband total number: 12) as shown in FIG. 9 as with Embodiment 1. Subbands used for HeNB 300 in each frame are assumed to be six (the number of used subbands: 6).
In FIG. 9 , specification section 301 specifies subbands (subbands 3 to 11 ) to which signals from the MUEs are assigned, using the signals detected in detection section 201 . Furthermore, specification section 301 specifies received signal power in subbands to which signals from the MUEs are assigned. In HeNB 300 , subbands 6 to 8 (subbands to which signals from MUE 2 are assigned) have the highest received signal power, subbands 3 to 5 (subbands to which signals from MUE 3 are assigned) have the second highest received signal power, and subbands 9 to 11 (subbands to which signals from MUE 1 are assigned) have the third highest received signal power as shown in FIG. 9 . Meanwhile, HeNB 300 does not detect any signals from the MUEs in subbands 1 , 2 , and 12 , and received signal power in subbands 1 , 2 , and 12 is lowest.
Subband number determination section 302 then classifies subbands 1 to 12 shown in FIG. 9 into a plurality of subband groups according to the level of the specified received signal power in specification section 301 . Specifically, subband number determination section 302 classifies subbands into a subband group including subbands 1 , 2 , and 12 having the lowest received signal power, a subband group including subbands 9 to 11 having the second lowest received signal power, a subband group including subbands 3 to 5 having the third lowest received signal power, and a subband group including subbands 6 to 8 having the highest received signal power.
Next, subband number determination section 302 determines the number of subbands used for the assigning pattern every subband group such that HeNB 300 is assigned to a subband group having lower received signal power. Since the number of subbands used for HeNB 300 is six, subband number determination section 302 determines the number of subbands used for an assigning pattern in a subband group including subbands 1 , 2 , and 12 as three, determines the number of subbands used for the assigning pattern in a subband group including subbands 9 to 11 as two, determines the number of subbands used for the assigning pattern in a subband group including subbands 3 to 5 as one, and determines the number of subbands used for the assigning pattern in a subband group including subbands 6 to 8 as zero, for example.
Pattern generating section 303 then generates a subband assigning pattern based on the number of subbands in each subband group determined in subband number determination section 302 . That is to say, pattern generating section 303 generates the subband assigning pattern such that a larger number of subbands forming a subband group having lower received signal power are assigned to HeNB 300 . As shown in FIG. 9 , pattern generating section 303 extracts all subbands 1 , 2 , and 12 since subband number determination section 302 has determined the number of subbands as three in the subband group including subbands 1 , 2 , and 12 , for example. As shown in FIG. 9 , pattern generating section 303 also extracts two subbands of subbands 9 and 11 from subbands 9 to 11 since subband number determination section 302 has determined the number of subbands as two in the subband group including subbands 9 to 11 . The same applies to subband group including subbands 3 to 5 shown in FIG. 9 . On the other hand, pattern generating section 303 extracts no subband in the subband group including subbands 6 to 8 shown in FIG. 9 .
That is to say, pattern generating section 303 generates the assigning pattern including the combination of subbands 1 , 2 , 4 , 9 , 11 , and 12 among subbands 1 to 12 as shown in FIG. 9 .
In view of the above, a subband group having lower received signal power (that is to say, the power of interference signals to HeNB 300 (or the HUE)) has a larger number of subbands used for the assigning pattern. Here, subbands forming a subband group having the highest received signal power (subbands 6 to 8 ) are not used for the assigning pattern as with Embodiment 2.
Here, HUE 1 , HUE 2 , and HUE 3 are assumed to be connected to HeNB 300 . As shown in FIG. 9 , assignment section 102 assigns subbands 4 and 12 to HUE 1 , assigns subbands 2 and 9 to HUE 2 , assigns subbands 1 and 11 to HUE 3 among subbands 1 , 2 , 4 , 9 , 11 , and 12 shown in the assigning pattern.
As the power of signals from the MUE (received signal power), that is, the power of interference signals is high, the effect on the communications of HeNB 300 increases. Meanwhile, subbands having lower power (the power of interference signals) of signals from the MUE are likely to be assigned to HeNB 300 . In other words, subbands having higher power (the power of interference signals) of signals from the MUE are not likely to be assigned to HeNB 300 . Especially, HeNB 300 does not assign subbands (subbands 6 to 8 in FIG. 9 ) forming a subband group having the highest power of signals (the power of interference signals) from the MUE among a plurality of subbands to HeNB 300 .
The present embodiment avoids assigning subbands to HeNB 300 (HUE) in a subband which is likely to receive interference from an MUE and therefore can suppress interference from the MUE.
HeNB 300 also generates a subband assigning pattern based on only signals from the MUE, which are detected in detection section 201 , a total number of subbands available for HeNB 300 , and the number of subbands used for HeNB 300 as with Embodiment 2. That is to say, HeNB 300 can generate the subband assigning pattern without exchanging information (for example, information showing the used MeNB subbands) with the MeNB as with Embodiment 2.
In view of the above, the present embodiment can suppress interference between an HeNB and an MeNB without exchanging information between the MeNB and the HeNB as with Embodiment 1. The present embodiment also avoids assigning subbands to the HeNB in subbands receiving interference from the MUE (interference bands) as with Embodiment 2. Furthermore, HeNB is likely to be assigned to subbands which are not likely to receive interference from the MUE in the present embodiment. This makes it possible to further suppress interference between the MeNB and the HeNB.
In the present embodiment, a case has been described where pattern generating section 303 in HeNB 300 employs the same subband combination included in a subband assigning pattern every frame. However, pattern generating section 303 may vary a subband combination included in the assigning pattern every frame by combining the present embodiment with Embodiment 1. As shown in FIG. 10 , subband number determination section 302 , for example, classifies twelve subbands 1 to 12 into a plurality of subband groups according to received signal power, and determines the number of subbands used for the assigning pattern every subband group such that HeNB 300 is assigned to subbands forming a subband group having lower received signal power as with FIG. 9 . Pattern generating section 303 then extracts subbands used for the assigning pattern based on the number of subbands in each subband group, which is determined in subband number determination section 302 . At this time, pattern generating section 303 varies a combination of subbands used for an assigning pattern every frame as shown in FIG. 10 .
This avoid assigning subbands to HeNB 300 in a subband which is likely to receive interference, and can thereby suppress interference between the MeNB and HeNB 300 as with the present embodiment. Furthermore, Embodiment 3 can randomize (average) interference between the MeNB and HeNB 300 using an assigning pattern having a subband combination which varies every frame and therefore suppress interference between the MeNB and HeNB 300 as with Embodiment 1.
(Embodiment 4)
In HeNB 300 ( FIG. 8 ) according to the present embodiment, subband number determination section 302 first classifies a plurality of subbands available for HeNB 300 into a plurality of subband groups according to the level of the received signal power specified in specification section 301 as with Embodiment 3. Subband number determination section 302 then determines the number of subbands used for an assigning pattern every subband group such that subbands are assigned to HeNB 300 in sequence from subbands forming a subband group having lower received signal power. Here, a total number of subbands determined in each subband group is the number of subbands used for HeNB 300 .
Pattern generating section 303 generates an assigning pattern of subbands assigned to HeNB 300 (and an HUE) based on the number of subbands determined in subband number determination section 302 . Specifically, pattern generating section 303 generates a subband assigning pattern such that subbands are assigned to HeNB 300 in sequence from subbands forming a subband group having lower received signal power among a plurality of subband groups classified according to the level of received signal power.
Next, a process in HeNB 300 according to the present embodiment will be described in detail.
In the following description, subbands available for HeNB 300 are assumed to be subbands 1 to 12 (subband total number: 12) as shown in FIG. 11 as with Embodiment 3 ( FIG. 9 ). Subbands used for HeNB 300 in each frame are assumed to be four (the number of used subbands: 4).
In HeNB 300 , subbands 6 to 8 (subbands to which signals from MUE 2 are assigned) have the highest received signal power, subbands 3 to 5 (subbands to which signals from MUE 3 are assigned) have the second highest received signal power, and subbands 9 to 11 (subbands to which signals from MUE 1 are assigned) have the third highest received signal power as shown in FIG. 11 as with Embodiment 3 ( FIG. 9 ). On the other hand, HeNB 300 does not detect any signals from the MUEs in subbands 1 , 2 , and 12 , and the received signal power is the lowest level.
Accordingly, subband number determination section 302 classifies subbands 1 to 12 shown in FIG. 11 into a subband group including subbands 1 , 2 , and 12 having the lowest received signal power, a subband group including subbands 9 to 11 having the second lowest received signal power, a subband group including subbands 3 to 5 having the third lowest received signal power, and a subband group including subbands 6 to 8 having the highest received signal power as with Embodiment 3 ( FIG. 9 ).
Next, subband number determination section 302 determines the number of subbands used for the assigning pattern every subband group such that subbands are assigned to HeNB 300 in sequence from subbands forming a subband group having lower received signal power. Since the number of subbands used for HeNB 300 is four, for example, subband number determination section 302 first determines the number of subbands used for the assigning pattern in a subband group including subbands 1 , 2 , and 12 having the lowest received signal power as three. Here, while the number of subbands used for HeNB 300 is four, the number of determined subbands is three. Subband number determination section 302 therefore needs to further determine another subband. Subband number determination section 302 further determines the number of subbands used for the assigning pattern as one (=4−3) in a subband group including subbands 9 to 11 having the second lowest received signal power. A total number of subbands determined in each subband group is the number of used subbands for HeNB 300 (that is to say, four). Accordingly, subband number determination section 302 determines the number of subbands used for the assigning pattern as zero in a subband group including subbands 3 to 5 and a subband group including subbands 6 to 8 .
Pattern generating section 303 then generates the subband assigning pattern such that subbands are assigned to HeNB 300 in sequence from subbands forming a subband group having lower received signal power. As shown in FIG. 11 , pattern generating section 303 , for example, extracts all subbands 1 , 2 , and 12 since subband number determination section 302 has determined the number of subbands as three in the subband group including subbands 1 , 2 , and 12 . As shown in FIG. 11 , pattern generating section 303 also extracts, one subband, for example, subband 10 , from subbands 9 to 11 since subband number determination section 302 has determined the number of subbands as one in the subband group including subbands 9 to 11 . On the other hand, pattern generating section 303 extracts no subband in the subband group including subbands 3 to 5 and the subband group including subbands 6 to 8 shown in FIG. 11 .
That is to say, pattern generating section 303 generates an assigning pattern including a combination of subbands 1 , 2 , 10 , and 12 among subbands 1 to 12 as shown in FIG. 11 .
Here, HUE 1 and HUE 2 are assumed to be connected to HeNB 300 . Assignment section 102 assigns subbands 1 and 12 to HUE 1 , and assigns subbands 2 and 10 to HUE 2 among subbands 1 , 2 , 10 , and 12 shown in the assigning pattern as shown in FIG. 11 .
In view of the above, HeNB 300 assigns subbands to HeNB 300 in sequence from subbands (subbands having lower interference from signals of an MUE) having lower received signal power (that is to say, power of interference signals to HeNB 300 (or an HUE)). The subbands assigned to HeNB 300 (subbands included in the assigning pattern) are a combination of subbands having lower interference from signals of the MUEs among a plurality of subbands available for HeNB 300 (subbands 1 to 12 in FIG. 11 ). This makes it possible to suppress interference between HeNB 300 (HUE) and an MeNB (MUE) to the lowest level.
HeNB 300 also generates the subband assigning pattern based on only signals from the MUEs, which are detected in detection section 201 , a total number of subbands available for HeNB 300 , and the number of subband used for HeNB 300 as with Embodiment 3. That is to say, HeNB 300 can generate the subband assigning pattern without exchanging information (for example, information showing the used MeNB subbands) with the MeNB as with Embodiment 3.
In view of the above, the present embodiment can suppress interference between an HeNB and an MeNB without exchanging information between the MeNB and the HeNB as with Embodiment 1. The present embodiment preferentially assigns subbands to the HeNB in sequence from subbands having a lower effect from signals of the MUEs, and therefore can suppress interference between the MeNB and the HeNB to the lowest level.
In the present embodiment, a case has been described where pattern generating section 303 in HeNB 300 employs the same subband combination included in a subband assigning pattern every frame. However, pattern generating section 303 may vary a subband combination included in the assigning pattern every frame by combining the present embodiment with Embodiment 1, As shown in FIG. 12 , subband number determination section 302 , for example, classifies twelve subbands 1 to 12 into a plurality of subband groups according to received signal power, and determines the number of subbands used for the assigning pattern every subband group in such that subbands are assigned to HeNB 300 in sequence from subbands forming a subband group having lower received signal power as with FIG. 11 . Pattern generating section 303 then extracts subbands used for the assigning pattern based on the number of subbands in each subband group determined in subband number determination section 302 . At this time, pattern generating section 303 varies a combination of subbands used for an assigning pattern every frame as shown in FIG. 12 . Furthermore, pattern generating section 303 varies subbands assigned to different HUEs (HUE 1 and HUE 2 in FIG. 12 ) in subbands used for the assigning pattern, every frame.
This makes it possible to preferentially assign subbands to HeNB 300 in sequence from subbands having a lower effect from signals of the MUEs, and to suppress interference between the MeNB and the HeNB to the lowest level as with the present embodiment. Furthermore, Embodiment 4 can randomize (average) interference between the MeNB and HeNB 300 using an assigning pattern having a subband combination which varies every frame and therefore suppress interference between the MeNB and HeNB 300 as with Embodiment 1.
(Embodiment 5)
In the present embodiment, a plurality of HeNBs which are adjacent to each other will be described. In the following description, a case where three HeNBs 1 to 3 are adjacent to each other will be described as shown in FIG. 13 . HeNBs 1 to 3 shown in FIG. 13 include the configuration of HeNB 100 ( FIG. 1 ) according to Embodiment 1, for example.
That is to say, pattern generating section 101 in each of HeNBs 1 to 3 shown in FIG. 13 generates an assigning pattern having a combination of subbands assigned to the HeNB varies every frame in subbands available for the HeNB as shown in FIG. 3 . It is noted that HeNBs 1 to 3 shown in FIG. 13 independently set assigning patterns used in the HeNBs.
In view of the above, HeNBs 1 to 3 shown in FIG. 13 which are adjacent to each other independently generate assigning patterns. HeNBs 1 to 3 are therefore likely to use different assigning patterns in each frame. Specifically, although there is a possibility that a plurality of adjacent HeNBs generate the identical assigning patterns in a certain frame (the probability of using the same subband), the probability of generating the identical assigning patterns in a plurality of continuous frames is reduced. This makes it possible to randomize (average) interference which may be given between HeNBs 1 to 3 adjacent to each other shown in FIG. 13 .
Accordingly, the present embodiment, for example, can reduce the probability that signals transmitted from a certain HeNB to an HUE connected to the HeNB in downlink interfere with an HUE connected to another HeNB adjacent thereto over a plurality of frames. The present embodiment can reduce the probability that signals transmitted from an HUE connected to a certain HeNB to the HeNB in uplink interfere with another adjacent HeNB over a plurality of frames.
HeNBs 1 to 3 shown in FIG. 13 can randomize (average) interference between HeNBs and an MeNB (not shown) as with Embodiment 1 and can suppress interference between the HeNBs and the MeNB.
HeNBs 1 to 3 shown in FIG. 13 each generate a subband assigning pattern based on only a total number of subbands available for HeNB 100 , and the number of subbands used for HeNB 100 as with Embodiment 1. That is to say, HeNBs 1 to 3 shown in FIG. 13 can each generate the subband assigning pattern without exchanging information (for example, information showing the used subbands in each apparatus) with the MeNB, and with adjacent HeNBs.
In view of the above, the present embodiment can suppress interference between an HeNB and an MeNB without exchanging information between the MeNB and the HeNB as with Embodiment 1. Furthermore, the present embodiment can suppress interference between HeNBs without exchanging information between a plurality of adjacent HeNBs.
In the present embodiment, a case has been described where HeNBs 1 to 3 shown in FIG. 13 include the configuration of HeNB 100 ( FIG. 1 ) according to Embodiment 1. However, HeNBs 1 to 3 shown in FIG. 13 may include the configuration of the HeNB according to Embodiments 2 to 4 (HeNB 200 ( FIG. 5 ), HeNB 300 ( FIG. 8 )). In this case, the HeNB can obtain the same effect as that of each embodiment and suppress interference with HeNBs as with the present embodiment,
Embodiments of the present invention have been described above.
The embodiments have been described using an LTE system as example, but the present invention is not limited to this, and can also be applied to all radio communication standards which allow a mixture of the MeNB and the HeNB.
In the above embodiments, an example in which continuous subbands are used has been described. The present invention is not limited to the case of using continuous subbands, but can be applied to a case of using discontinuous subbands, for example, as shown in FIGS. 14 and 15 and can obtain the same effect as that of the above embodiments. In FIG. 14 and FIG. 15 , the groups of subbands 1 to 4 , subbands 5 to 7 , and subbands 8 to 10 are discontinuous. FIG. 14 shows a case of employing the same subband combination included in a subband assigning pattern every frame, FIG. 15 shows a case of using different subband combination included in a subband assigning pattern every frame.
The disclosure of Japanese Patent Application No. 2010-047985, filed on Mar. 4, 2010, including the specification, drawings and abstract, is incorporated herein by reference in its entirety.
Industrial Applicability
The present invention is suitable for a mobile communication system including an MeNB, an MUE, an HeNB, and an HUE.
Reference Signs List
100 , 200 , 300 HeNB
101 , 203 , 303 Pattern generating section
102 Assignment section
103 Notification section
201 Detection section
202 , 301 Specification section
302 Subband number determination section
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Provided is a small base station apparatus (HeNB), wherein interference between the HeNB and an MeNB can be inhibited, without any exchange of information between the HeNB and the MeNB. In the HeNB ( 100 ), which forms a cell smaller than a cell formed by the MeNB, a pattern generation unit ( 101 ) generates an assigning pattern of subbands to be assigned to the HeNB ( 100 ), from among a plurality of subbands that can be used by the HeNB ( 100 ), wherein combinations of subbands are different for each of the frames. An assignment unit ( 102 ) assigns subbands to communication terminal apparatuses connected to the HeNB ( 100 ), on the basis of the assigning pattern.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image reproduction device and method thereof, and more particularly to a technique of reproducing thumbnail images of a stereo image (hereinafter referred to as a “3D image”) composed of plural images obtained by capturing the identical subject from plural viewpoints.
2. Description of the Related Art
There has hitherto been proposed an image data production device which produces an image file having recorded thereon a 3D image being image information corresponding to plural viewpoints, its thumbnail image, and three-dimensional control information for displaying as the 3D image (Japanese Patent Application Laid-Open No. 2004-349731).
In Japanese Patent Application Laid-Open No. 2004-349731, as the thumbnail image corresponding to the 3D image, there is described the following plural types of thumbnail images and the like.
(1) Images obtained by directly scaling down and arranging 3D images of all viewpoints (2) Image obtained by extracting and scaling down a 3D image of one viewpoint (3) Image embedded with a symbol indicating that the image is three-dimensional
There has also been proposed an image file production device which produces a stereo image file (3D image file) having recorded thereon a 3D image and a thumbnail image file having recorded thereon a two-dimensional image (hereinafter referred to as a “2D image”) as the thumbnail image of the 3D image (Japanese Patent Application Laid-Open No. 2004-349732). The 3D image file and the thumbnail image file corresponding to the 3D image are named under the naming rule based on DCF (Design rule for Camera File system: unified recording format for digital camera), but these two image files are named so as to have the same file name and different extensions, so that these are associated with each other.
In Japanese Patent Application Laid-Open No. 2004-349731, as the thumbnail image corresponding to a 3D image, there is described an example of plural types of thumbnail images, but only one thumbnail image is recorded in one image file. Thus, even in an image reproduction device for 3D image capable of reproducing various types of thumbnail images, one fixed thumbnail image preliminarily recorded on the image file is all that can be displayed; for example, when different types of thumbnail images are recommended by each device, there is a problem that displaying of thumbnail images recommended by each device or displaying of the thumbnail image of a type preliminarily set by the user cannot be performed.
In Japanese Patent Application Laid-Open No. 2004-349732, there is no description of the type of thumbnail image corresponding to 3D image. Consequently, when an image reproduction device for reproducing a 3D image reproduces a thumbnail image based on a thumbnail image file having recorded thereon a 2D thumbnail image, one fixed thumbnail image preliminarily recorded on the thumbnail image file is all that can be displayed. Thus, the problem similar to that with the invention described in Japanese Patent Application Laid-Open No. 2004-349731 arises.
The present invention addresses this problem, with the object of providing an image reproduction device and method thereof which can reproduce in a short length of time, an optimum one of different thumbnail images of plural types produced as the thumbnail image of a 3D image, or a thumbnail image of a type desired by a user.
SUMMARY OF THE INVENTION
To achieve the above object, an image reproduction device according to a first aspect of the present invention includes: a thumbnail image read device which reads a thumbnail image file having recorded thereon two or more types of thumbnail images produced based on a stereo image composed of a plurality of images obtained by capturing the identical subject from a plurality of viewpoints; a thumbnail image selection device which selects one thumbnail image to be used for displaying from among the plurality of thumbnail images recorded on the read thumbnail image file; and a thumbnail image reproduction device which causes the selected thumbnail image to be displayed on a display device.
That is, a desired thumbnail image is selected and displayed from the thumbnail image file having preliminarily recorded thereon two or more types of thumbnail images, so a thumbnail image of a type set by the device, or a desired thumbnail image appropriately set by the user can be reproduced in a short length of time.
A thumbnail image can be produced based on the original image (stereo image) at the time of reproduction; but in this case, it takes time to produce a thumbnail image, and particularly when many 3D image files are recorded, it takes long time to display all the thumbnail images. According to the aspect of the present invention, since a plurality of types of thumbnail images file preliminarily produced are looked up, a thumbnail image can be quickly displayed.
According to a second aspect of the present invention, the image reproduction device of the first aspect further includes a stereo image read device which reads a stereo image file having recorded thereon the stereo image and associated with the thumbnail image file, wherein when a thumbnail image is contained in the stereo image file associated with the thumbnail image file, the thumbnail image read device also reads the thumbnail image.
Accordingly, even in a reproduction device which does not look up a thumbnail image file, also, the thumbnail image of a 3D image can be quickly reproduced without producing a new thumbnail image based on the 3D image.
According to a third aspect of the present invention, in the image reproduction device of the first aspect: the thumbnail image file may contain management information including a thumbnail image identifier for identifying the type of each thumbnail image; and the thumbnail image selection device automatically selects based on the management information, a thumbnail image corresponding to a preliminarily set thumbnail image identifier. Accordingly, in the image reproduction device, the type of a thumbnail image to be reproduced can be easily selected.
An image reproduction device according to a fourth aspect of the present invention includes: a thumbnail image read device which reads a thumbnail image file having recorded thereon one or more types of thumbnail images produced based on a stereo image composed of a plurality of images obtained by capturing the identical subject from a plurality of viewpoints; a stereo image read device which reads a stereo image file associated with the thumbnail image file and having recorded thereon along with the stereo image, one thumbnail image of a type different from the thumbnail image recorded on the thumbnail image file; a thumbnail image selection device which selects one thumbnail image from among the plurality of thumbnail images recorded on the read thumbnail image file and the stereo image file; and a thumbnail image reproduction device which causes the selected thumbnail image to be displayed on a display device.
That is, a desired thumbnail image can be selected from among the plurality of types of thumbnail images recorded in a classified manner on the stereo image file and the thumbnail image file. In addition, one thumbnail image is recorded on the stereo image file, so the thumbnail image of the 3D image can be quickly reproduced even in a reproduction device which does not look up the thumbnail image file.
According to a fifth aspect of the present invention, in the image reproduction device of the fourth aspect: each of the thumbnail image file and the stereo image file may contain management information including a thumbnail image identifier for identifying the type of a thumbnail image; and the thumbnail image selection device automatically selects based on the management information, a thumbnail image corresponding to a preliminarily set thumbnail image identifier.
An image reproduction device according to a sixth aspect of the present invention includes: an image read device which reads a stereo image file having recorded thereon a stereo image composed of a plurality of images obtained by capturing the identical subject from a plurality of viewpoints, and two or more types of thumbnail images produced based on the stereo image; a thumbnail image selection device which selects one thumbnail image to be used for displaying from among the plurality of thumbnail images recorded on the read stereo image file; and a thumbnail image reproduction device which causes the selected thumbnail image to be displayed on a display device.
According to the sixth aspect of the present invention, since a desired thumbnail image is selected and displayed from the stereo image file having preliminarily recorded thereon two or more types of thumbnail images, the thumbnail image of a type set by the device, or a desired thumbnail image appropriately set by the user can be reproduced in a short length of time. In addition, even in the reproduction device which does not look up a thumbnail image file, the thumbnail image of the 3D image can be quickly reproduced without producing a new thumbnail image based on the 3D image.
According to a seventh aspect of the present invention, in provided the image reproduction device of the sixth aspect: the stereo image file contains management information including a thumbnail image identifier for identifying the type of a thumbnail image; and the thumbnail image selection device automatically selects based on the management information, a thumbnail image corresponding to a preliminarily set thumbnail image identifier.
According to an eighth aspect of the present invention, there is provided the image reproduction device of any one of the second, fourth, fifth, sixth and seventh aspects further includes: an instruction device which gives an instruction of reproducing a stereo image corresponding to the thumbnail image displayed on the display device; and a stereo image display device which reads in response to inputting of the instruction from the instruction device, the stereo image instructed to be reproduced from the stereo image file and causes the stereo image to be displayed on the display device.
An image reproduction method according to a ninth aspect of the present invention includes the steps of: reading a thumbnail image file having sequentially recorded thereon two or more types of thumbnail images produced based on a stereo image composed of a plurality of images obtained by capturing the identical subject from a plurality of viewpoints; selecting one thumbnail image to be used for displaying from among the plurality of thumbnail images recorded on the read thumbnail image file; and causing the selected thumbnail image to be displayed on a display device.
According to a tenth aspect of the present invention, the image reproduction method of the ninth aspect further includes the step of reading a stereo image file having recorded thereon the stereo image and associated with the thumbnail image file, wherein the thumbnail image selection step selects one thumbnail image to be used for displaying from among the plurality of thumbnail images recorded on the read thumbnail image file and the stereo image file.
An image reproduction method according to an eleventh aspect of the present invention includes the steps of: reading a thumbnail image file having recorded thereon one or more types of thumbnail images produced based on a stereo image composed of a plurality of images obtained by capturing the identical subject from a plurality of viewpoints; reading a stereo image file associated with the thumbnail image file and having recorded thereon along with the stereo image, one thumbnail image of a type different from the thumbnail images recorded on the thumbnail image file; selecting one thumbnail image to be used for displaying from among the plurality of thumbnail images recorded on the read thumbnail image file and the stereo image file; and causing the selected thumbnail image to be displayed on a display device.
An image reproduction method according to a twelfth aspect of the present invention includes the steps of: reading a stereo image file having recorded thereon a stereo image composed of a plurality of images obtained by capturing the identical subject from a plurality of viewpoints, and two or more types of thumbnail images produced based on the stereo image; selecting one thumbnail image to be used for displaying from among the plurality of thumbnail images recorded on the read stereo image file; and causing the selected thumbnail image to be displayed on a display device.
According to aspects of the present invention, since a thumbnail image of a type set by the device is selected and displayed from among plural different-type thumbnail images preliminarily produced as the thumbnail image of a 3D image and recorded on the image file, an optimum thumbnail image or a thumbnail image of a type desired by the user can be reproduced in a short length of time.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating a schematic configuration of an imaging device (digital camera) with an image reproduction device according to the present invention;
FIG. 2 is a block diagram illustrating an internal configuration of an image file production device arranged in the digital camera;
FIGS. 3A to 3D are views illustrating examples of plural types of thumbnail images produced by a thumbnail image production unit;
FIG. 4 is a view illustrating an exemplary file structure of a thumbnail image file;
FIGS. 5A to 5D are views illustrating an exemplary file structure of a 3D image file;
FIG. 6 is a view illustrating a directory structure of a recording medium having stored therein the 3D image file and the thumbnail image file;
FIG. 7 is a view illustrating a file structure of a thumbnail image file according to another embodiment;
FIG. 8 is a view illustrating a directory structure of a recording medium having stored therein the 3D image file and the thumbnail image file;
FIG. 9 is a block diagram illustrating an internal configuration of an image production device arranged in a digital camera;
FIG. 10 is a flowchart illustrating an embodiment of the image reproduction operation in reproduction mode;
FIG. 11 is a flowchart illustrating details of the thumbnail image file read procedure in the flowchart illustrated in FIG. 10 :
FIG. 12 is a flowchart illustrating another embodiment of the image reproduction operation in reproduction mode; and
FIGS. 13A , 13 B and 13 C are each a view illustrating a file structure according to another embodiment of 3D image file.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described below with reference to the accompanying drawings showing preferred embodiments thereof.
[Schematic Configuration of Digital Camera]
FIG. 1 is a block diagram illustrating a schematic configuration of an imaging device with an image reproduction device according to the present invention.
The imaging device (digital camera) 1 includes imaging units 10 and 12 which capture the identical subject from plural viewpoints (viewpoint 1 and viewpoint N (N being 2 or more)) to capture a 3D image, an image file production device 100 which retrieves plural images captured by the imaging units 10 and 12 , a recording device 200 which records a 3D image file and a thumbnail image file produced by the image file production device 100 onto an external recording medium such as a memory card, or a recording medium incorporated in the camera, and an image reproduction device 300 which reads the 3D image file and thumbnail image file recorded on the recording medium and reproduces a 3D image and thumbnail image.
[Image File Production Device]
FIG. 2 is a block diagram illustrating an internal configuration of an image file production device 100 .
The image file production device 100 mainly includes a 3D image production unit 110 , a thumbnail image production unit 120 , a tag data production unit 130 , a thumbnail image file production unit 140 , a 3D image file production unit 150 , a controller 160 and a storage unit 170 .
The controller 160 controls each unit in an integrated manner according to a prescribed program. Stored in the storage unit 170 are the program executed by the controller 160 , setting data of each unit, and the like.
The 3D image production unit 110 is input with plural images captured by the imaging units 10 and 12 arranged in plural viewpoint positions, and according to the present embodiment, produces a 3D image composed of plural images integrated as one image.
When no integrated 3D image is produced, the 3D image production unit 110 may be omitted. In addition to the plural images obtained by capturing the identical subject from plural viewpoints, the plural images input to the 3D image production unit 110 include a range image indicating imaging distances determined for each pixel of an image representing the subject. Alternatively, the 3D image production unit 110 may produce a range image based on plural images obtained by capturing the identical subject from plural viewpoints.
The thumbnail image production unit 120 produces thumbnail images of plural types corresponding to a 3D image based on the integrated image produced by the 3D image production unit 110 or on prior-to-integration images of plural viewpoints.
FIGS. 3A to 3D illustrate an example of plural types of thumbnail images produced by the thumbnail image production unit 120 .
FIG. 3A illustrates a thumbnail image produced by scaling down an integrated image (3D image) of four viewpoints in a case where they are produced by the 3D image production unit 110 to which images of four viewpoints are input.
FIG. 3B illustrates a thumbnail image produced by scaling down only a left image (or right image) when the right and left images of two viewpoints are input.
FIG. 3C illustrates a thumbnail image with a symbol mark (R) indicating the right image, produced by scaling down only a right image (or left image) when the right and left images of two viewpoints are input.
FIG. 3D illustrates a thumbnail image produced by integrating a scaled-down 2D image with a scaled-down range image when the 2D image and the range image corresponding to the 2D image are input. In this case, the range image is an image in which as the distance is closer, a higher pixel value is allotted.
The tag data production unit 130 produces tag data of a thumbnail image file and 3D image file, and outputs the respective tag data to the thumbnail image file production unit 140 and 3D image file production unit 150 . In the thumbnail image file described later, plural types of thumbnail images are recorded in combination; thus, the tag data production unit 130 also produces management information for managing plural thumbnail images, so tag data produced by the tag data production unit 130 are different from those of conventional image files.
The thumbnail image file production unit 140 produces a thumbnail image file based on the plural types of thumbnail images produced by the thumbnail image production unit 120 and the tag data for thumbnail image file produced by the tag data production unit 130 .
FIG. 4 illustrates an exemplary file structure of the thumbnail image file produced by the thumbnail image file production unit 140 .
As illustrated in FIG. 4 , in the thumbnail image file, the management information on plural types of thumbnail images is recorded immediately subsequent to a header, and plural thumbnail images (first, second, . . . , k-th) are sequentially recorded subsequent to the management information.
Here, the management information includes, as illustrated in FIG. 4 , “thumbnail image identifier” (type ID) for identifying the type of each thumbnail image and “offset” indicating the position (address) in the file on which the thumbnail image corresponding to type ID is recorded.
In this case, since the management information is recorded immediately subsequent to the header, it is possible to select a thumbnail image to be reproduced before reading the thumbnail image, and thus it is possible to read only the thumbnail image to be reproduced.
Meanwhile, the 3D image file production unit 150 produces a 3D image file based on the integrated image (3D image) produced by the 3D image production unit 110 and tag data for 3D image file produced by the tag data production unit 130 .
FIGS. 5A to 5D illustrate an exemplary file structure of the 3D image file produced by the 3D image file production unit 150 .
The 3D image file illustrated in FIG. 5A has a file structure in which one integrated image (3D image) is recorded subsequent to the header on which tag data are recorded. The tag data include information indicating the areas of images of four viewpoints and information (length of baseline, angle of convergence and the like) on the position of viewpoints of each image; these pieces of information are used during reproduction in the 3D image reproduction device.
The 3D image file illustrated in FIG. 5B has a file structure in which plural images (3D image) captured from plural viewpoints are recorded being combined in each frame one by one subsequent to the header on which tag data are recorded. The tag data include information indicating the areas of plural images and information (length of baseline, angle of convergence and the like) on the position of viewpoints of each image; these pieces of information are used during reproduction in the 3D image reproduction device.
The 3D image file illustrated in FIG. 5C has a file structure in which a thumbnail image is recorded subsequent to the header on which tag data are recorded, and management information of the thumbnail image is recorded subsequent to the thumbnail image, and a 3D image is recorded subsequent to the management information.
The 3D image file illustrated in FIG. 5D has a file structure in which management information is recorded subsequent to the header on which tag data are recorded, and a thumbnail image is recorded subsequent to the management information, and a 3D image is recorded subsequent to the thumbnail image.
In producing the 3D image file illustrated in FIG. 5C or 5 D, the 3D image file production unit 150 is input with one of plural types of thumbnail images produced by the thumbnail image production unit 120 . As the management information, a thumbnail image identifier (type ID) of thumbnail image in the 3D image file is recorded. As the 3D image to be recorded on the 3D image file illustrated in FIG. 5C or 5 D, any of the 3D images illustrated in FIGS. 5A and 5B can be used.
[Recording Device]
In the recording device 200 illustrated in FIG. 1 , a thumbnail image file produced by the thumbnail image file production unit 140 and a 3D image file produced by the 3D image file production unit 150 are recorded on a recording medium.
FIG. 6 illustrates a directory structure of the recording medium. As illustrated in FIG. 6 , a DCF folder ( 100 -FUJI . . . ) is produced under a DCF image route directory DCIM (Digital Camera IMages), and the 3D image file and thumbnail image file are stored in the DCF folder.
Folder names and file names are automatically produced based on a prescribed naming rule and assigned to the DCF folder, 3D image file and thumbnail image file produced in this way.
In the present embodiment, folder names and file names are automatically produced based on the DCF rule. Here, the folder name of DCF folder is produced as illustrated in the following table.
TABLE 1
FREE CHARACTER
RULE
FOLDER NUMBER (100-999)
(5 CHARACTERS)
EXAMPLE
100
ABCDE
In this case, it is recommended that, when no DCF folder is present directly under DCF image route directory DCIM, any value be allotted to the initial value of the folder number, or when a DCF folder is present, a sequence number (maximum number+1) be allotted to the folder number of the newly produced DCF folder.
The file name of image file (DCF file) is produced as illustrated in the following table.
TABLE 2
FREE CHARACTER
RULE
(4 CHARACTERS)
FILE NUMBER (0001-9999)
EXAMPLE
ABCD
0001
In this case, it is recommended that, when no DCF file is present in the DCF folder, any value be allotted to the initial value of the file number, or when a DCF file is present, a sequence number (maximum number+1) be allotted to the file number of the newly produced DCF file.
As illustrated in FIG. 6 , the 3D image file and the thumbnail image file corresponding to the 3D image file have different extensions (the extension of the 3D image file being jpg, the extension of thumbnail image file being th 3 ) but a shared file name; thus the two files are associated with each other.
FIG. 7 is a view illustrating a file structure of a thumbnail image file according to another embodiment produced by the thumbnail image file production unit 140 illustrated in FIG. 2 .
As illustrated in FIG. 7 , in this thumbnail image file, one (first thumbnail image) of plural types of thumbnail images is recorded immediately subsequent to a header, and management information is recorded immediately subsequent to the first thumbnail image, and thumbnail images (second thumbnail image, . . . , k-th thumbnail image) other than the first thumbnail image are recorded immediately subsequent to the management information.
In the management information, “offset” of the second and subsequent thumbnail images and “thumbnail image identifier” (type ID) of the first to the k-th thumbnail images are recorded.
According to the thumbnail image file of the above file structure, even in an image reproduction device which cannot look up the management information, since the file structure from the header till the first thumbnail image is under a specification identical to that of DCF-rule thumbnail images file, at least the first thumbnail image can be reproduced.
Also, as the extension of the thumbnail image file, thm (the same as the DCF thumbnail image file) is used as illustrated in FIG. 8 . Accordingly, compatibility with the conventional DCF thumbnail image file can be ensured.
[Image Reproduction Device]
Details of the image reproduction device 300 illustrated in FIG. 1 will be described.
FIG. 9 is a block diagram illustrating an internal configuration of the image production device 300 .
The image reproduction device 300 mainly includes a 3D image read unit 310 , a thumbnail image file read unit 320 , a thumbnail image selection unit 330 , a 3D image reproduction unit 340 , a thumbnail image reproduction unit 350 , a controller 360 and a storage unit 370 .
The controller 360 controls each unit in an integrated manner according to a prescribed program. Stored in the storage unit 370 are the program executed by the controller 360 , setting data of each unit, and the like.
The 3D image read unit 310 and the thumbnail image file read unit 320 can read a 3D image file and a thumbnail image file from the recording device 200 , respectively.
The thumbnail image selection unit 330 selects a thumbnail image of a type preliminarily set on the device from among plural types of thumbnail images, and outputs the selected thumbnail image to the thumbnail image reproduction unit 350 .
The thumbnail image reproduction unit 350 causes the thumbnail image input via the thumbnail image selection unit 330 to be displayed on a display unit, such as a liquid crystal monitor arranged in the digital camera 1 , or on an external display unit for 3D image connected to the digital camera 1 .
When the user selects a desired thumbnail image (a 3D image to be reproduced) from among the thumbnail images (for example, an index image composed of plural thumbnail images) displayed on the display unit, the 3D image reproduction unit 340 displays the 3D image input via the 3D image read unit 310 on the display unit.
The 3D image reproduction unit 340 produces a 3D image which can be recognized as a 3D image when special eyeglasses are worn and displays the image on the display unit, or when the display unit can reproduce a 3D image without using special eyeglasses (for example, a directional display), produces a 3D image corresponding to the display unit and displays the image on the display unit.
[Procedure of Image Reproduction]
When the digital camera 1 illustrated in FIG. 1 is switched to reproduction mode, 3D image reproduction becomes possible.
FIGS. 10 and 11 are flowcharts illustrating the image reproduction operation in reproduction mode.
As illustrated in FIG. 10 , firstly a 3D image file is read from the recording medium (step S 10 ) and subsequently a thumbnail image file is read (step S 20 ).
Here, since there is a case ( FIG. 5A or 5 B) where no thumbnail image lies in the 3D image file, it is as illustrated in FIG. 11 , it is determined whether a thumbnail image lies in the 3D image file or not (step S 0 ), and if so, the operation proceeds to step S 10 ; if not, step S 10 is skipped and the operation proceeds to step S 20 .
Subsequently, a thumbnail image to be displayed is selected from among the read thumbnail images (step S 30 ). More specifically, the type ID of the thumbnail image recorded in the management information of tag data illustrated in FIG. 4 is checked against the preliminarily set thumbnail image identifier (type ID), and a thumbnail image having type ID identical to the preliminarily set type ID is selected. In this case, when the image files are read at steps S 10 and S 20 , it is sufficient to read only the management information in the image file.
Subsequently, the thumbnail image selected at step S 30 is read from the thumbnail image file (or the 3D image file) based on the offset to the thumbnail image recorded in a manner associated with type ID, and the read thumbnail image is caused to be displayed on the display unit (step S 40 ).
Generally, the thumbnail image is displayed as an index image composed of plural thumbnail images. More specifically, one thumbnail image is selected for each image file stored in the recording medium, and the selected thumbnail images are read to produce and display an index image of thumbnail images.
Subsequently, a desired thumbnail image is selected from the index image, and when an instruction of reproducing a 3D image corresponding to that thumbnail image is given (step S 50 ), a 3D image is read from a 3D image file associated with the thumbnail image file on which the selected thumbnail image has been recorded, and the 3D image is caused to be displayed on the display unit (step S 60 ). When the selected thumbnail image has been recorded on the 3D image file, the original image (3D image) is read from that 3D image file to display the 3D image on the display unit.
FIG. 12 is a flowchart illustrating another embodiment of the image reproduction operation in reproduction mode. In FIG. 12 , the same step numbers are assigned to steps corresponding to those of the flowchart of FIG. 10 , and a detailed explanation thereof is omitted.
The image reproduction operation illustrated in FIG. 12 is different from the one illustrated in FIG. 10 in that when a thumbnail image desired to be displayed has been recorded in the 3D image file, the operation of reading a thumbnail image file is omitted.
More specifically, it is determined whether or not a thumbnail image has been recorded on the 3D image file read from the recording medium (step S 100 ).
If so, the type ID of the thumbnail image recorded in the management information (refer to FIG. 5C ) is read (step S 110 ), and it is determined whether or not this read type ID agrees with type ID of the thumbnail image desired to be displayed (step S 120 ).
If the read type ID agrees with the type ID of the thumbnail image to be displayed, a thumbnail image recorded on the 3D image file is read (step S 130 ), the operation proceeds to step S 40 . In this case, a thumbnail image file is not read.
Meanwhile, at step S 100 , when it is determined that no thumbnail image has been recorded on the 3D image file ( FIG. 5A or 5 B), or at step S 120 , when it is determined that the thumbnail image recorded on the 3D image file is not the thumbnail image desired to be displayed (disagreement of type ID), the operation proceeds to step S 20 .
At step S 20 , a thumbnail image file is read. Then, the type ID of the thumbnail image is read from the management information of the thumbnail image file (step S 140 ), and a thumbnail image having type ID identical to the preliminarily set type ID is read from the thumbnail image file (step S 150 ), and the operation proceeds to step S 40 .
When a thumbnail image desired to be displayed does not lie in either of the 3D image file and thumbnail image file, one of the plural thumbnail images (for example, the first thumbnail image) may be displayed.
Alternatively, when a thumbnail image desired to be displayed does not lie in either of the 3D image file and thumbnail image file, the thumbnail image desired to be displayed may be produced and displayed based on the 3D image. Further, the thumbnail image thus produced may be added to the thumbnail image file and at the same time the management information may be updated.
Another Embodiment of 3D Image File
According to the aforementioned embodiment, a 3D image file and thumbnail image file are separately produced and recorded in a manner associated with each other. However, according to another embodiment of 3D image file, plural types of thumbnail images are recorded on a 3D image file without producing a thumbnail image file.
Each of FIGS. 13A , 13 B and 13 C is a view illustrating a file structure according to another embodiment of 3D image file.
The first file structure of 3D image file illustrated in FIG. 13A is obtained by replacing the area for thumbnail image and management information illustrated in FIG. 5C with that for the first to the k-th thumbnail images of FIG. 7 .
There can be a case where compatibility can be ensured by using the first file structure described above. However, if it is limited to a case where the structure is applied to the existing Exif (Exchange Image File Format) standard, actually the size limit of Exif standard may be infringed depending on the total value of thumbnail image size, so that compatibility cannot be ensured.
The second file structure of 3D image file illustrated in FIG. 13B can solve the above problem of the first file structure; the structure is obtained by storing only the first thumbnail image in the area of thumbnail image and management information of FIG. 5C and arranging, subsequent to the 3D image (original image), the thumbnail management information and the second to the k-th thumbnail images.
The 3D image in the first or second file structure may be an integrated image as illustrated in FIG. 5A or an image obtained by separating and combining images corresponding to each viewpoint illustrated in FIG. 5B .
The third file structure of 3D image file illustrated in FIG. 13C is applied only to a case where images corresponding to each viewpoint are separately arranged as the 3D image; the header, the first thumbnail image and the 3D image corresponding to the first viewpoint are recorded in an Exif-compliant format, and subsequent to these, thumbnail management information, the second to the k-th thumbnails and the 3D images corresponding to the second to the k-th viewpoints are arranged.
In the image file production devices which produce the 3D image files illustrated in FIGS. 13A 13 B and 13 C, the thumbnail image file production unit 140 in the image file production device 100 illustrated in FIG. 2 is not needed, and plural types of thumbnail images produced by the thumbnail image production unit 120 and tag data produced by the tag data production unit 130 are all output to the 3D image file production unit 150 to produce the 3D image files illustrated in FIGS. 13A , 13 B and 13 C.
Further, in the image file production device which reproduces the 3D image file illustrated in FIG. 13 , the thumbnail image read unit 320 in the image reproduction device 300 illustrated in FIG. 9 is not needed.
In the above description of the present embodiment, the image file production device and image reproduction device are incorporated in the digital camera. However, the image file production device and image reproduction device may be each a separate device.
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An image reproduction device comprises: a thumbnail image read device which reads a thumbnail image file having recorded thereon two or more types of thumbnail images produced based on a stereo image composed of a plurality of images obtained by capturing the identical subject from a plurality of viewpoints; a thumbnail image selection device which selects one thumbnail image to be used for displaying from among the plurality of thumbnail images recorded on the read thumbnail image file; and a thumbnail image reproduction device which causes the selected thumbnail image to be displayed on a display device. Thereby, the device enables to reproduce in a short length of time, an optimum one of different thumbnail images of plural types, or a thumbnail image of a type desired by a user.
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RELATED APPLICATION
[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/091,037, filed Dec. 12, 2014, the entire disclosure of which is hereby incorporated herein by reference.
TECHNICAL FIELD
[0002] In various embodiments, the present invention relates to additive manufacturing techniques such as three-dimensional (3D) printing, and in particular to the additive manufacturing of metallic objects.
BACKGROUND
[0003] Additive manufacturing techniques such as 3D printing are rapidly being adopted as useful techniques for a host of different applications, including rapid prototyping and the fabrication of specialty components. To date, most additive manufacturing processes have utilized polymeric materials, which are melted, layer-by-layer, into specified patterns to form 3D objects. The additive manufacturing of metallic objects presented additional challenges, but techniques have been more recently developed to address these challenges.
[0004] Existing technologies for the additive manufacture of metal structures may generally be classified in three categories: laser sintering, adhesive bonding followed by sintering, and molten metal deposition. The two sintering technologies use a bed of metal powder in the build area, and the powder particles are selectively joined to one another to form the desired pattern. When one layer is completed, more metal powder is spread over the first layer, and powder particles are joined to the previous layer in the pattern required for that layer. The process continues with fresh powder spread over the entire surface of the build area and then selectively joined, building the desired structure layer by layer. The finished part is retrieved from inside the powder bed, and the powder is then emptied from the build area to begin the next part.
[0005] However, the use of metal powder as a raw material can be problematic for several reasons. Metal powder is expensive to produce, and generally is more expensive than a wire made from the same material for the same volume of material. Metal powders are difficult and dangerous to handle. For example, metal powder that is spilled may form dust in the air that is dangerous to inhale, and such dust may even be an explosion risk. In addition, the amount of powder required for conventional additive manufacturing technologies is many times greater than that required to make the part, as the entire build area must be filled with powder. This increases the cost of the process and leads to attrition and waste of powder, which may not be readily reused. Conventional powder-based processes are also very slow because the spreading of concurrent layers of powder typically must be done precisely to the required layer thickness and must be done across the entire build area for each layer.
[0006] Laser sintering uses a high power laser as the source of heat to fuse particles. Lasers have many safety risks, especially at the powers required for fusing metals. Using lasers as a source of heat causes issues because the particles must be heated top down to add enough heat to fuse them to the previous layer. Such top-down heating requires much more heat than would be needed if the heat was applied directly to the joining surfaces, which slows down the overall process and causes the excess heat to be dissipated into the powder bed. Because of this, there is the danger of unwanted sintering particles in the area around that which the laser is heating. Therefore, the process requires the use of metals and alloys that have poor heat conduction.
[0007] Adhesive bonding uses glue to join adjacent powder particles instead of directly fusing the particles by laser energy, but the process is otherwise similar. Glue is selectively sprayed to form a pattern, and powder is added layer by layer to form the structure. To make a mechanically sound metal part, the structure generally must be removed from the powder bed and placed in a furnace to sinter the bonded metal powders. The sintering multiplies the complexity of the process and well as the time required to produce parts.
[0008] In molten-metal deposition techniques, heat to liquefy the metal is derived from plasma or electric arc. The molten metal is then sprayed in the pattern desired to form a structure by building layers as the metal cools. The resolution achieved by spraying metal is generally poor compared to other processes, to the extent that hybrid machines have been developed to deposit metal, allow it to cool, and then use a milling tool to machine it to size. The speed of the process is slow because sufficient time must be allowed to cool the underlying layer before it can be built upon, as the heat generated by the plasma or electric arc are very high. It is further slowed by the machining process if good resolution is required.
[0009] In view of the foregoing, there is a need for improved additive manufacturing techniques for the fabrication of metallic parts that do not utilize metal powders as raw materials, do not generate excessive heat, and do not require time-consuming and uneconomical sintering steps for solidification.
SUMMARY
[0010] In accordance with various embodiments of the present invention, metal objects are fabricated layer by layer in a controlled manner utilizing metal wire as feedstock, enabling the manufacture of 3D structures. Embodiments of the invention only utilize as much feedstock as required to form the object being fabricated, eliminating most (if not all) of the waste and/or recovery processes associated with powder-based techniques. The metallic wire feedstock is more easily handled and enables faster fabrication, as it is deployed only at the exact points where the solid structure is being fabricated. The wire is heated upon contact with the fabrication platform or a previous layer of the structure being fabricated via a pulse of electric current, forming a molten droplet (or “particle”) at the point of contact. The molten droplets adhere in place, enabling the layer-by-layer fabrication of the part. Advantageously, only the single melting/deposition step is required, obviating the need for separate sintering steps to bond the metal particles together. In addition, current is typically only applied to the wire upon contact with the fabrication platform or a previous layer of the structure being fabricated, thereby minimizing heating of the wire (and the structure being fabricated) and preventing formation of electrical arcs at the wire tip.
[0011] Embodiments of the present invention have the advantage that heat is generated at the point of contact between adjacent particles (i.e., between the tip of the wire feedstock and the fabrication platform or a previous layer of the structure being fabricated), exactly where the heat is required for fusion. This allows much lower heat input than that utilized in laser-heating techniques. The lower heat input enables faster overall processing, no risk of unwanted heating of surrounding particles, and the use of many different metals and alloys. It also reduces safety concerns, and the build area typically is maintained at a lower temperature.
[0012] Embodiments of the present invention solve the problems inherent to existing approaches by leveraging knowledge of established gas metals arc welding (GMAW), resistive spot welding (RSW), and computer-aided manufacturing (CAM) technologies. Embodiments of the invention utilize inert gas shielding and a fine metal wire electrode as both an electrode and source of metal feedstock (similarly to GMAW), an electric current that heats and melts the feed metal and base metal due to contact resistance (similarly to RSW), and can control the motion of the metal wire electrode/feedstock in three dimensions through a computer-controlled interface, allowing for deposition of material in the desired shape (similarly to CAM). These features enable the production of 3D metal structures using any of a variety of metals and metal alloys with minimal safety concerns at low cost.
[0013] In an aspect, embodiments of the invention feature a method of layer-by-layer fabrication of a three-dimensional metallic structure upon an electrically conductive base. A first layer of the structure is formed by depositing a plurality of metal particles onto the base. Each metal particle is deposited by (i) disposing a metal wire in contact with the base, and (ii) passing an electrical current through the metal wire and the base. A portion of the metal wire melts to form the metal particle on the base. One or more subsequent layers of the structure are formed by depositing pluralities of metal particles over the first layer of the structure. Each metal particle is deposited by (i) disposing the metal wire in contact with a previously deposited metal particle, and (ii) passing an electrical current through the metal wire, the previously deposited metal particle, and the base. A portion of the metal wire melts to form the metal particle on the previously deposited metal particle.
[0014] Embodiments of the invention may include one or more of the following in any of a variety of combinations. A gas may be flowed over at least a tip of the wire during deposition of the metal particles. The gas may reduce or substantially prevent oxidation of the metal particles during deposition. The gas may increase a cooling rate of the metal particles during deposition. After deposition of each metal particle, a relative position of the metal wire and the base may be changed with one or more mechanical actuators (e.g., stepper motors, solenoids, etc.). The metal wire may include, consist essentially of, or consist of stainless steel, copper, and/or aluminum. A porosity of at least a portion of the structure may be controlled by (i) altering a spacing between adjoining contact points between the metal wire and the base or underlying particles, and/or (ii) altering a magnitude of the current applied between the metal wire and the base. A computational representation of a three-dimensional structure may be stored. Sets of data corresponding to successive layers may be extracted from the computational representation, and each of the forming steps may be performed in accordance with the data. A size of at least one metal particle may be selected by controlling a speed of retraction of the metal wire therefrom (e.g., during and/or after deposition). An outer portion of the metal wire may be removed before the metal wire is melted to form at least one of the metal particles. An amount of metal wire utilized to form the first layer and the one or more subsequent layers of the structure may be tracked and/or stored. The metal particles may be formed in response to heat arising from, at least in part (e.g., substantially entirely due to), contact resistance at the tip of the wire (i.e., resistance resulting from contact between the tip of the wire and an underlying structure, e.g., the base or an underlying particle).
[0015] In another aspect, embodiments of the invention feature an apparatus for the layer-by-layer fabrication of a three-dimensional metallic structure from particles formed by melting a metal wire. The apparatus includes or consists essentially of an electrically conductive base for supporting the structure during fabrication, a wire-feeding mechanism for dispensing wire over the base, one or more mechanical actuators for controlling a relative position of the base and the wire-feeding mechanism, a power supply for applying a current between the wire and the base sufficient to cause the wire to release a metal particle (e.g., via heat arising from contact resistance between the wire and an object in contact therewith, e.g., the base), and circuitry for controlling the one or more actuators and the power supply to create the three-dimensional metallic structure on the base from successively released metal particles.
[0016] Embodiments of the invention may include one or more of the following in any of a variety of combinations. The circuitry may include or consist essentially of a computer-based controller for controlling the one or more mechanical actuators and/or the power supply. The computer-based controller may include or consist essentially of a computer memory and a 3D rendering module. The computer memory may store a computational representation of a three-dimensional structure. The 3D rendering module may extract sets of data corresponding to successive layers from the computational representation. The controller may cause the mechanical actuators and the power supply to form successive layers deposited metal particles in accordance with the data. Metal wire may be disposed within the wire-feeding mechanism.
[0017] In yet another aspect, embodiments of the invention feature a method of layer-by-layer fabrication of a three-dimensional metallic structure upon an electrically conductive base. A sacrificial raft structure is formed by depositing a plurality of metal particles onto the base. Each metal particle is deposited by (i) disposing a first metal wire in contact with the base, and (ii) passing an electrical current through the first metal wire and the base. A portion of the first metal wire melts to form the metal particle on the base. A first layer of the structure is formed by depositing a plurality of metal particles onto the sacrificial raft structure. Each metal particle is deposited by (i) disposing a second metal wire in contact with the sacrificial raft structure, and (ii) passing an electrical current through the second metal wire, the sacrificial raft structure, and the base. A portion of the second metal wire melts to form the metal particle on the sacrificial raft structure. One or more subsequent layers of the structure are formed by depositing pluralities of metal particles over the first layer of the structure. Each metal particle is deposited by (i) disposing the second metal wire in contact with a previously deposited metal particle, and (ii) passing an electrical current through the second metal wire, the previously deposited metal particle, the sacrificial raft structure, and the base. A portion of the second metal wire melts to form the metal particle on the previously deposited metal particle.
[0018] Embodiments of the invention may include one or more of the following in any of a variety of combinations. The density and/or the porosity of the sacrificial raft structure may be less than that of the structure. The sacrificial raft structure may define one or more openings therethrough. The sacrificial raft structure may include, consist essentially of, or consist of a plurality of layers. A thickness of at least one of the layers of the sacrificial raft structure may be greater than a thickness of at least one of the layers of the structure. A thickness of at least one of the layers of the sacrificial raft structure may be greater than a thickness of all of the layers of the structure. A thickness of a bottommost layer of the sacrificial raft structure (i.e., the layer of the sacrificial raft structure directly in contact with the base) may be greater than a thickness of at least one of, or even all of, the layers of the structure. After fabrication of the structure, the sacrificial raft structure may be removed from the base, and at least a portion of the structure may remain on the sacrificial raft structure. After the sacrificial raft structure is removed from the base, the sacrificial raft structure may be separated from the structure. The first and second metal wires may include, consist essentially of, or consist of different materials (e.g., different metals). The first and second metal wires may include, consist essentially of, or consist of the same material (e.g., the same metal). The metal particles may be formed in response to heat arising from, at least in part (e.g., substantially entirely due to), contact resistance at the tip of the wire (i.e., resistance resulting from contact between the tip of the wire and an underlying structure, e.g., the base, the raft, or an underlying particle).
[0019] These and other objects, along with advantages and features of the present invention herein disclosed, will become more apparent through reference to the following description, the accompanying drawings, and the claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and may exist in various combinations and permutations. As used herein, the terms “approximately” and “substantially” mean ±10%, and in some embodiments, ±5%. The term “consists essentially of” means excluding other materials that contribute to function, unless otherwise defined herein. Nonetheless, such other materials may be present, collectively or individually, in trace amounts. For example, a structure consisting essentially of multiple metals will generally include only those metals and only unintentional impurities (which may be metallic or non-metallic) that may be detectable via chemical analysis but do not contribute to function.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the present invention are described with reference to the following drawings, in which:
[0021] FIG. 1 is a schematic of an additive manufacturing apparatus in accordance with various embodiments of the invention;
[0022] FIGS. 2A-2F are schematics of the deposition of metallic particles during the fabrication of a three-dimensional object in accordance with various embodiments of the invention;
[0023] FIG. 3 is a schematic of a printed three-dimensional object having regions of different particle resolutions in accordance with various embodiments of the invention;
[0024] FIG. 4A is a schematic of particles printed with low porosity in accordance with various embodiments of the invention;
[0025] FIG. 4B is a schematic of particles printed with high porosity in accordance with various embodiments of the invention;
[0026] FIGS. 5A-5C schematically depict deposition of a particle from a wire in accordance with various embodiments of the invention;
[0027] FIGS. 5D-5F schematically depict particles of different sizes deposited via use of different wire-retraction rates in accordance with various embodiments of the invention;
[0028] FIG. 6 is a schematic of a mechanical wire-tracking system in accordance with various embodiments of the invention;
[0029] FIG. 7 is a schematic of an optical wire-tracking system in accordance with various embodiments of the invention;
[0030] FIG. 8 is a schematic of an anti jamming mechanism in accordance with various embodiments of the invention;
[0031] FIGS. 9A and 9B are schematic plan views of sacrificial structures printed between the baseplate and a desired printed part in accordance with various embodiments of the invention;
[0032] FIG. 9C is a schematic cross-sectional view of a part printed on a sacrificial structure on a baseplate in accordance with various embodiments of the invention;
[0033] FIG. 10A is a schematic illustration of removal of a sacrificial structure and printed part thereover from a baseplate in accordance with various embodiments of the invention; and
[0034] FIG. 10B is a schematic illustration of removal of a sacrificial structure from a printed part in accordance with various embodiments of the invention.
DETAILED DESCRIPTION
[0035] In accordance with embodiments of the invention, 3D metal structures may be fabricated layer-by-layer using an apparatus 100 , as shown in FIG. 1 . Apparatus 100 includes a mechanical gantry 105 capable of motion in one or more of five or six axes of control (e.g., one or more of the XYZ planes) via one or more actuators 110 (e.g., motors such as stepper motors). As shown, apparatus 100 also includes a wire feeder 115 that positions a metal wire 120 inside the apparatus, provides an electrical connection to the metal wire 120 , and continuously feeds metal wire 120 from a source 125 (e.g., a spool) into the apparatus. A baseplate 130 is also typically positioned inside the apparatus and provides an electrical connection; the vertical motion of the baseplate 130 may be controlled via an actuator 135 (e.g., a motor such as a stepper motor). An electric power supply 140 connects to the metal wire 120 and the baseplate 130 , enabling electrical connection therebetween. The motion of the gantry 105 and the motion of the wire feeder 115 are controlled by a controller 145 . The application of electric current from the power supply 140 , as well as the power level and duration of the current, is controlled by the controller 145 .
[0036] The computer-based controller 145 in accordance with embodiments of the invention may include, for example, a computer memory 150 and a 3D rendering module 155 . Computational representations of 3D structures may be stored in the computer memory 150 , and the 3D rendering module 155 may extract sets of data corresponding to successive layers of a desired 3D structure from the computational representation. The controller 145 may control the mechanical actuators 110 , 135 , wire-feeding mechanism 115 , and power supply 140 to form successive layers deposited metal particles in accordance with the data.
[0037] The computer-based control system (or “controller”) 145 in accordance with embodiments of the present invention may include or consist essentially of a general-purpose computing device in the form of a computer including a processing unit (or “computer processor”) 160 , the system memory 150 , and a system bus 165 that couples various system components including the system memory 150 to the processing unit 160 . Computers typically include a variety of computer-readable media that can form part of the system memory 150 and be read by the processing unit 160 . By way of example, and not limitation, computer readable media may include computer storage media and/or communication media. The system memory 150 may include computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM) and random access memory (RAM). A basic input/output system (BIOS), containing the basic routines that help to transfer information between elements, such as during start-up, is typically stored in ROM. RAM typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit 160 . The data or program modules may include an operating system, application programs, other program modules, and program data. The operating system may be or include a variety of operating systems such as Microsoft WINDOWS operating system, the Unix operating system, the Linux operating system, the Xenix operating system, the IBM AIX operating system, the Hewlett Packard UX operating system, the Novell NETWARE operating system, the Sun Microsystems SOLARIS operating system, the OS/2 operating system, the BeOS operating system, the MACINTOSH operating system, the APACHE operating system, an OPENSTEP operating system or another operating system of platform.
[0038] Any suitable programming language may be used to implement without undue experimentation the functions described herein. Illustratively, the programming language used may include assembly language, Ada, APL, Basic, C, C++, C*, COBOL, dBase, Forth, FORTRAN, Java, Modula-2, Pascal, Prolog, Python, REXX, and/or JavaScript for example. Further, it is not necessary that a single type of instruction or programming language be utilized in conjunction with the operation of systems and techniques of the invention. Rather, any number of different programming languages may be utilized as is necessary or desirable.
[0039] The computing environment may also include other removable/nonremovable, volatile/nonvolatile computer storage media. For example, a hard disk drive may read or write to nonremovable, nonvolatile magnetic media. A magnetic disk drive may read from or writes to a removable, nonvolatile magnetic disk, and an optical disk drive may read from or write to a removable, nonvolatile optical disk such as a CD-ROM or other optical media. Other removable/nonremovable, volatile/nonvolatile computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The storage media are typically connected to the system bus through a removable or non-removable memory interface.
[0040] The processing unit 160 that executes commands and instructions may be a general-purpose computer processor, but may utilize any of a wide variety of other technologies including special-purpose hardware, a microcomputer, mini-computer, mainframe computer, programmed micro-processor, micro-controller, peripheral integrated circuit element, a CSIC (Customer Specific Integrated Circuit), ASIC (Application Specific Integrated Circuit), a logic circuit, a digital signal processor, a programmable logic device such as an FPGA (Field Programmable Gate Array), PLD (Programmable Logic Device), PLA (Programmable Logic Array), RFID processor, smart chip, or any other device or arrangement of devices that is capable of implementing the steps of the processes of embodiments of the invention.
[0041] Embodiments of the invention form metal structures via metal particles formed at the molten tip of a metal wire, as shown in FIGS. 2A-2F . As shown, the formation of the desired 3D structure typically begins with the deposition of a single particle 200 melted from the wire 120 onto the baseplate 130 . The particle 200 and subsequent particles may have any morphology but may be considered to be substantially spherical. Additional particles 205 , 210 are deposited one by one adjacent to previously deposited particles, and the heat from the formation of each new particle partially melts the adjacent particles and fuses them together. Once all of the particles that need to be adjacent to one another on a single layer for the desired structure have been deposited, deposition of particles 215 , 220 , 225 begins one by one on top of the previous layer of fused particles 200 , 205 , 210 . Deposition continues in this manner, layer by layer, until the entire structure is completed. Each layer of the structure may be composed of a different number of particles, depending on the desired shape of the structure, and particles in an overlying layer need not be (but may be, in various embodiments) deposited directly on top of a particle of an underlying layer.
[0042] The diameter of the particles will typically determine the height of each layer, and as such may at least in part dictate the resolution at which structures may be formed. The diameter of the particles may be changed by changing the diameter of the metal wire 120 , as well as the deposition parameters (e.g., current level), and thus the resolution of the structure may be controlled dynamically during the process. In general, higher resolution will increase the time required to form the structure, and lower resolution will decrease it. Therefore, sections of 3D structures may be fabricated with high resolution to hold a tight mechanical tolerance or to be more visually appealing, and others sections may be fabricated at low resolution to increase the speed of deposition, as shown in FIG. 3 . FIG. 3 depicts a printed structure 300 composed of a low-resolution portion 305 at least partially surrounded by a high-resolution portion 310 . As shown, the low-resolution portion 305 includes or consists essentially of multiple larger particles 315 , while high-resolution portion 310 includes or consists essentially of multiple smaller particles 320 . The portions 305 , 310 may include pores 325 between particles that result from empty space remaining between particles during melting thereof.
[0043] The porosity of the fabricated 3D structure may be determined, at least in part, by the spacing and/or extent of fusion between adjacent particles, as shown in FIGS. 4A and 4B . FIG. 4A depicts two particles fused closely together, resulting in a smaller porosity signified by smaller porous region 400 (which may, in a completed part, be at least a portion of a pore therewithin), and FIG. 4B depicts two particles fused together to a lesser extent, resulting in higher porosity signified by a larger porous region 410 . Deposition parameters may be varied to determine the degree of fusion between particles, mainly through the amount of heat generated during deposition. If heat is increased, fusion between particles will be greater, and porosity will generally be lower. If enough heat is generated, the resulting structure may have substantially no porosity, which may be preferred to achieve specific mechanical properties. Conversely, less heat will cause less fusion, and porosity will be higher. A more porous structure will typically have a lower weight than a fully dense structure. Since the amount of heat may be controlled dynamically during deposition, sections of the 3D structure may be intentionally made more porous than other sections. For example, a porous filter may be contained in an internal passage of a larger 3D structure. In general, the application of less heat will require less time, so the speed of deposition may be increased if porosity is desired or may be tolerated in sections of the structure. Materials with high porosity typically have low tensile strength but may achieve good compressive strength. Structures may be designed so that areas in compressive loading may be produced with some porosity, leading to faster deposition speed, and also lower weight of the finished structure.
[0044] In accordance with embodiments of the present invention, metal particles are formed by melting the tip of the metal wire 120 with electric current. The wire 120 may have a substantially circular cross-section, but in other embodiments the wire 120 has a cross-section that is substantially rectangular, square, or ovular. The diameter (or other lateral cross-sectional dimension) of the metal wire 120 may be chosen based on the desired properties of deposition, but generally may be between approximately 0.1 mm and approximately 1 mm. The metal wire 120 is one electrode, and the metallic baseplate 130 of the apparatus 100 is the other electrode, as shown in FIG. 1 . When the wire 120 is in physical contact with the baseplate 130 , the two are also in electrical contact. There is an electrical resistance between the wire 120 and baseplate 130 (i.e., contact resistance) due to the small surface area of the fine wire 120 and the microscopic imperfections on the surface of the baseplate 130 and the tip of the wire 120 . The contact resistance between the wire 120 and baseplate 130 is the highest electrical resistance experienced by an electric current that is passed between the two electrodes (i.e., the wire 120 and baseplate 130 ), and the local area at the contact point is heated according to Equation 1 (i.e., Joule's First Law).
[0000] Q=I 2 ×R×t Equation 1
[0045] The heat generated (Q) is in excess of the heat required to melt the tip of the wire 120 into a particle and to fuse the particle to adjacent particles. The heat is determined by the amount of current passed (I), the contact resistance between the wire 120 and baseplate 130 (R), and the duration of the application of current (t). (Thus, embodiments of the present invention form particles without use or generation of electrical arcs and/or plasma, but rather utilize contact-resistance-based melting of the wire.) Current and time (I and t) may be controlled during the process via controller 145 and power supply 140 , and in various embodiments of the invention, a high current is utilized for a short duration (as opposed to a lower current for a longer duration) to increase the speed of deposition. The required current and duration depends on the desired deposition properties, but these may generally range from approximately 10 Amperes (A) to approximately 1000 A and approximately 0.01 seconds (s) to approximately 1 s. After the first layer of fused particles is completed, the previous layer of particles, which are in electrical contact with the baseplate 130 , act as the second electrode. As the process proceeds, one electrode (the metal wire 120 ) is consumed as metal from the tip of the wire 120 is utilized to form the particle.
[0046] The use of a consumable metal wire as an electrode is similar to GMAW, in that the wire feedstock may be stored on large spools and feed continuously to continue the deposition process. Thus, there are many metal and metal alloy wires that are readily available at low cost. The devices and techniques for the mechanical motion of feeding the wire and making electrical contact between the wire and the power supply are also known to those of skill in the art. In order to protect the deposited metal from oxidation, an inert gas (such as Ar) or semi-inert gas (such as N 2 or CO 2 ) may be flowed over the area around the metal wire electrode to displace oxygen. For example, gas may be flowed continuously at a rate of, e.g., approximately 0.7 m 3 /hr during the deposition process when the metal is at high temperature or is molten. Advantageously, gas flow rates may be increased beyond what is required to provide a shielding effect to increase the rate at which deposited metal cools. Cooling rate may also affect the resulting mechanical properties of the metal, and with dynamic control during deposition, sections of the structure may be fabricated with different mechanical properties. For example, a high cooling rate may be used on the surface of a structure to increase hardness and wear resistance, while a slower cooling rate may be used on the interior to maintain ductility and strength.
[0047] In accordance with embodiments of the invention, the material for the baseplate electrode 130 is selected for good electrical conductivity and compatibility with the metal that is being deposited. The baseplate 130 is typically non-consumable and thus is not damaged and need not be replaced during normal operation. The baseplate material may be chosen to allow weak adhesion of the deposited metal to it, so that the first layer of deposited metal will hold the structure firmly in place on the baseplate 130 during further deposition. For example, if the deposited metal is steel, copper or aluminum may be appropriate materials for the baseplate 130 . Copper and aluminum have a high electrical conductivity, will not alloy with steel and change the composition of the deposited metal, and have good thermal conductivity so heat generated at the deposition area may be quickly conducted away, and there is no danger of melting the baseplate 130 . The surface finish of the baseplate 130 may be slightly rough, so that the metal of the first layer melts into the fine surface features (e.g., scratches) of the baseplate 130 and allows for weak adhesion. The surface finish of the baseplate 130 may be chosen to give the appropriate amount of adhesion so the structure is held firmly during deposition, but that a reasonable force may be used to remove the finished structure from the baseplate 130 at the end of deposition. The baseplate 130 may be made easily replaceable so that it may be changed to an appropriate material for the desired deposition metal.
[0048] The morphology of the deposited particles may be controlled through the diameter of the metal wire 120 , as well as the deposition parameters. The diameter of the deposited particle will typically be roughly the same diameter as the wire 120 . The diameter of the particle may be increased by feeding additional wire 120 into the particle while it is still molten. The shape of the top of the particle may be influenced by the retraction of the wire 120 while the particle is still molten, for example, where the top of the particle may be drawn into a peak via wire retraction. If the particle is allowed to partially cool, the wire 120 may be used to push the top of the particle to flatten the particle. These manipulations of the particle morphology may be used to change the porosity of the structure.
[0049] Similarly, retraction of the still molten wire tip from the previously deposited particle may be used to control the morphology of the tip of the wire 120 , as illustrated in FIGS. 5A-5C . In various embodiments of the invention, if the wire 120 is retracted quickly, the tip will be drawn into a sharp point. FIG. 5A depicts the initial formation of a particle 500 melting from the tip of wire 120 . In FIG. 5B , the wire 120 is retracted from the particle 500 , which is still at least partially molten. As shown, the tip of the wire 120 begins to neck down, decreasing its diameter. FIG. 5C illustrates the sharp tip 510 of the wire 120 after full retraction and separation from the particle 500 . The speed to retraction may thus be used to control the diameter of the tip of the wire 120 . Since the diameter at the tip is the effective diameter of the wire 120 for the next deposition, this controlled necking may be used to deposit particles with a diameter smaller than the bulk wire diameter. In this manner, higher resolution deposition is possible with larger wire diameters. FIGS. 5D-5F illustrate different sized particles 500 that may be deposited using the same wire via control of the wire's retraction speed when depositing the previous particle.
[0050] Control of the application of electric current may be used to influence the deposition of particles. Open-loop control of the applied current is enabled via choosing the desired intensity of power along with the duration prior to deposition. The intensity level may be calibrated to achieve a specific voltage or current at a constant contact resistance. However, the contact resistance may vary at each deposition site, as well as vary during the particle deposition itself. Open-loop control may therefore result in the application of too much or too little heat during deposition, and the fusion between particles may be affected. With proper calibration, open-loop control may be used successfully for deposition. In other embodiments of the invention, closed-loop control is used. In closed-loop control, the voltage and current are measured during deposition, and the contact resistance may be calculated according to Equation 2 (i.e., Ohm's Law).
[0000] R=V/I Equation 2
[0051] Because the contact resistance is calculated dynamically, the power of the applied electric current may be precisely controlled, thus resulting in the exact amount of heat being applied during deposition to achieve the desired deposition parameters and/or particle characteristics. A small AC current on the order of 1 mV to 100 mV may be applied in addition to the DC current of the deposition circuit to determine the impedance response of the system. The impedance may also be measured dynamically and used for feedback control. Closed-loop control may beneficially eliminate failed parts due to incomplete fusion of particles and minimize heat input into the structure during deposition.
[0052] In addition to the data that may be measured from the electric circuit of the deposition (i.e., the circuit formed by the baseplate 130 and wire 120 via controller 145 and power supply 140 ), additional sensors may be utilized to gather complementary data. Temperature measurements of the deposition site on the baseplate 130 or other points on the printed part or apparatus 100 may be measured using contact sensors such as thermocouples or thermistors, and non-contact methods such as infrared (IR) sensors and optical pyrometry. Temperature data may then be used by the system control loop to ensure the desired deposition parameters.
[0053] Other sensors may be used to detect the build surface, i.e., the baseplate 130 or the previously deposited layer of particles of the part being printed. Sonar or capacitive response systems may be used to map the surface and detect any areas that are not in specification, allowing for corrective action (e.g., rework such as additional particle deposition in areas having high porosity or missing material). All the data collected for feedback control may also be logged and then analyzed at the network level to develop automatic calibration processes to improve the function of any connected apparatus 100 .
[0054] To take advantage of the particle-by-particle deposition mechanism in embodiments of the present invention, the design process may be tailored to make use of a voxel system. The 3D rendering module 155 may assign properties to certain sections of the part based the deposition parameters desired using, e.g., computer-aided design (CAD) software. For example, if an internal section of a part should be porous to act as a filter, that section in the CAD design may be selected, and the user may assign values to parameters such as the percent porosity desired. In tandem with the voxel-based extension for the 3D rendering module 155 , computer-aided manufacturing software may be utilized to translate the desired voxel properties into the toolpath and deposition parameters required to produce the user's CAD design.
[0055] Another example of a voxel-based design is the design of a heat sink. In the CAD design utilized by the 3D rendering module 155 , the user may specify properties such as the material and density to direct heat through a specific area of the part. This concept may be used to keep heat-sensitive areas of the same part cool, without having to make the part from multiple pieces or via multiple different depositions. The voxel-based design system may also be leveraged with control of surface textures of either external or internal surfaces. A surface may intentionally be made with a very high surface area to give a part a high-friction surface, a highly radiant surface to cool more effectively, give an electrode higher conductivity, or allow for enhanced adhesion of a surface coating.
[0056] To deposit particles in precise locations, the metal wire electrode 120 and baseplate 130 may be positioned with computer-controlled mechanical actuators 110 , 135 , in a manner similar to that utilized by CAM machine tools. There are many mechanical systems that may accomplish the required motion, using a combination of electric, hydraulic or pneumatic motors and linear actuators, belts, pulleys, lead screws, and other devices. In one embodiment, the metal wire electrode 120 is situated on a gantry system 105 that allows motion in the X and Y directions, as described above. The baseplate electrode 130 moves independently on the Z axis. The feed of metal wire 120 may be controlled by another independent actuator controlling source 125 . The timing, duration, and power of the electric current used for deposition are controlled by controller 145 . The formation of a structure, controlled by signals from controller 145 , may proceed according to the following example. The structure is a simple cube, formed from eight particles each having a diameter of 1 unit.
[0057] 1. The gantry 105 moves wire 120 to the first position (X 0 ,Y 0 ) in the XY plane.
[0058] 2. The baseplate 130 moves to a position close to the tip of the metal wire 120 in the Z axis (Z 0 ).
[0059] 3. Wire 120 is fed from source 125 until it contacts the baseplate 130 .
[0060] 4. Electric current flows through the electrodes (i.e., the baseplate 130 and wire 120 ), melting the tip of the wire 120 and forming a metal particle on the baseplate 130 .
[0061] 5. The gantry 105 moves the wire 120 to the next position in the XY plane (X 1 ,Y 0 ).
[0062] 6. Wire 120 is fed to contact the baseplate 130 , current is passed, and another particle is formed.
[0063] 7. The gantry 105 moves the wire 120 in the XY plane and forms two more particles at X 1 ,Y 1 and X 0 ,Y 1 .
[0064] 8. The baseplate 130 moves one unit away from the metal wire 120 (Z 1 ).
[0065] 9. The gantry 105 moves the wire 120 to (X 0 ,Y 0 ), wire 120 is fed from source 125 until it makes contact with the particle underneath, and a new particle is formed on top of the previously deposited particle.
[0066] 10. The gantry 105 moves the wire 120 to each remaining XY position again in order, depositing a particle at each on top of the previous layer.
[0067] Like many CAM tools, the metal-based additive manufacturing process in accordance with embodiments of the present invention may be combined with other tools and/or processes in a single machine. Examples of this are a gantry-type machine as described above with a polymer extruder tool and a milling cutter tool attached to the gantry alongside the metal deposition tool. In this manner, hybrid structures may be built from a combination of polymer and metal, using the combination to increase the speed of building the structure, reduce the cost of the structure, or using the material that has the desired properties for that portion of the structure. For example, a part fabricated in accordance with embodiments of the present invention may have a structure that is largely built from a non-conductive polymer but that also features internal printed metallic electric circuits. The milling cutter may be used to machine any precision surfaces required on the structure. This concept may be expanded to include any number of tools in a single machine to perform any operation required for the formation of the required structure.
[0068] Multiple parts may be produced in succession in an automated fashion with no human user involvement. After a part is complete, an arm may cross the baseplate 130 and remove the part, depositing it into a collection area. Once the baseplate 130 is cleared of the previous part and the removal arm, the next part may be fabricated. In some embodiments of the present invention, calculations for the deposition parameters performed by 3D rendering module 155 are based on a static diameter value for the metal wire or polymer filament. However, the diameter of the supplied filament may be variable, as described above, and these variations may cause poor printing performance, jamming/clogging of the wire feeder 115 (e.g., a nozzle), or in severe cases damage to mechanical systems of apparatus 100 . It may also be desirable to detect the absence of wire 120 to determine when the source 125 has been exhausted. Additionally, a precise measure of the absolute length of wire 120 consumed may be logged and used to develop algorithms to better project the total wire 120 required and the time to complete a print.
[0069] In various embodiments of the present invention, in order to sense and track the use of wire 120 (or its absence), the apparatus 100 incorporates a system that includes or consists essentially of either a mechanical wheel that is in contact with the wire 120 , or an optical system that has an unimpeded view of the 120 . FIG. 6 schematically depicts a mechanical wire-tracking system 600 that includes a wheel 610 that contacts the wire 120 at a point within the wire feeder 115 as the wire 120 is fed from source 125 during printing. The motion of the wire 120 may be recorded by a digital encoder connected to the wheel 610 . The amount of wire 120 utilized during a period of time may be calculated from the encoder readout. As shown, the wheel 610 may be connected to a mechanism such as a spring-loaded lever 620 that urges the wheel 610 against the wire 120 . In this manner, deflections of the lever 620 may be used to calculate the diameter of the wire 120 . Absence of wheel motion or a very small diameter measurement will typically indicate that the source 125 has been emptied of wire 120 .
[0070] FIG. 7 depicts an optical wire-tracking system 700 that may be incorporated into various embodiments of the present invention. An optical image sensor 710 may be utilized to determine movement in of the wire 120 based on microscopic changes in the wire's surface and therefore be used to measure absolute length of wire 120 utilized during a printing process. A light 720 angled on the backside of the wire 120 facing the sensor 710 may be used to measure the diameter of the wire 120 based on the area of light blocked by the wire 120 . Multiple sensors 710 may be used to provide more accurate measurements in multiple axes with respect to the wire 120 . Similarly to the wire-tracking system 600 , the motion and diameter of the wire 120 may be used to calculate total length of wire utilized, detect when source 125 is out of wire, etc.
[0071] Printers in accordance with embodiments of the present invention may also incorporate an anti jamming mechanism to prevent drastically oversized wire from causing a jam or other damage to the wire feeder (e.g., the nozzle thereof). For example, a ring having an inside diameter matching the maximum allowable wire diameter may be disposed within the wire feeder 115 or between the wire feeder 115 and the source 125 . The wire 120 may be passed through the ring, and if it is oversized, the wire may become stuck in the ring or otherwise be unable to pass through the feeder 115 for printing. This condition may be sensed by, e.g., wire-tracking system 600 or 700 , and reported to the operator. Additionally, FIG. 8 depicts an embodiment of such a ring 800 . As shown, ring 800 may have a sharp edge on the inner diameter so that the wire 120 may be automatically trimmed to the proper diameter as it passes through the ring 800 .
[0072] Some printed parts, particularly those having high densities and/or variable or complicated geometries, may be difficult to remove from the baseplate 130 after printing. In various embodiments of the invention, a sacrificial structure (or “raft”) may be printed on the baseplate 130 before the part and utilized to enable removal of the part from the baseplate 130 . In various embodiments, the structure of the raft is selected to facilitate anchoring of the part to the baseplate 130 and enable electrical conductivity between the part (i.e., the wire electrode) and the baseplate 130 while facilitating removal of the raft from the finished part after printing. Furthermore, rafts having the same size and/or shape and/or interior configuration may be utilized for parts having very different geometries, thereby enabling a standardized process for removal of different parts from the baseplate 130 —after printing, the raft (and the printed part thereover) is removed from the baseplate 130 , and then the raft is removed from the part. In various embodiments, the raft may include, consist essentially of, or consist of, e.g., metal and/or polymer. In various embodiments, the raft is not printed by the apparatus 100 but is provided by other means (e.g., fabricated by another apparatus and affixed (e.g., adhered) to the baseplate 130 prior to printing of a desired part). In various embodiments, the raft includes, consists essentially of, or consists of one or more materials different from that utilized to fabricate a part thereon. For example, wires including, consisting essentially of, or consisting of different metals may be utilized to print the raft and to print one or more parts thereover.
[0073] FIGS. 9A and 9B are schematic top views of rafts 900 fabricated in accordance with embodiments of the present invention. As shown, the raft may include or consist essentially of one or more layers of material printed (e.g., using wire 120 ) over the baseplate 130 before printing of the desired part. In order to facilitate subsequent removal of the raft from the printed part, the raft may be composed of, e.g., a series of stripes 910 or a grid pattern 920 of the printed material, as shown in FIGS. 9A and 9B . That is, in various embodiments, the raft 900 defines one or more openings therethrough that extend between the baseplate 130 and a part printed over the raft 900 , rather than the raft 900 being composed of a solid sheet of material. The raft 900 may be printed utilizing a wire 120 that corresponds to the wire 120 (i.e., the same material and/or the same wire diameter and/or deposition conditions) utilized to print the part over the raft 900 , or the raft 900 may be printed utilizing a different material, different wire diameter, and/or different deposition conditions (e.g., wire withdrawal rate).
[0074] In various embodiments, the raft 900 is at least partially composed of printed areas having thicknesses 930 with gaps 940 therebetween. The sizes of thicknesses 930 and/or gaps 940 may be selected to control the adhesion between the raft 900 and the printed part and/or the baseplate 130 . Instead or in addition, the height (i.e., vertical thickness) of all or a portion of the raft 900 may be selected to facilitate subsequent printing of a part thereover. FIG. 9C depicts a part 950 printed over an exemplary raft 900 composed of one or more bottom layers 960 , one or more middle layers 970 , and one or more top layers 980 . The bottom layer 960 may have a thickness greater than the layer thickness typically utilized for printing parts in order to, e.g., isolate the part from any roughness or unevenness of the surface of the baseplate 130 . For example, if printed parts are typically composed of layers having thicknesses of approximately 0.6 mm, then at least the bottom layer 960 of the raft 900 may have a thickness greater than 0.6 mm, e.g., greater than 1 mm, or even thicker. The exemplary raft 900 in FIG. 9C also contains one or more middle layers 970 that typically do not mechanically contact either the baseplate 130 or the part 950 . The middle layer(s) 970 may, for example, provide structural stability to the raft 900 while also providing electrical conductivity through the raft 900 . The top layer 980 may have a structure designed to control the amount of adhesion between the raft 900 and part 950 printed over the raft. For example, the porosity of top layer 980 and/or the size of gaps 940 of the top layer 980 may be increased to decrease the amount of surface area at the interface (and thus the adhesion) between the raft 900 and the part 950 .
[0075] Once the part 950 has been printed as detailed herein, the part 950 and the raft 900 may be separated from the baseplate 130 . FIG. 10A illustrates an exemplary embodiment in which a blade 1000 is utilized to separate the raft 900 from the baseplate 130 . As shown in FIG. 10B , after separation of the raft 900 from the baseplate 130 , the raft may be peeled away from the part 950 .
[0076] In accordance with various embodiments of the invention, the printing apparatus 100 may be a single “station” along an assembly line of modular automated manufacturing stations in order to leverage the automation capabilities of apparatus 100 . For example, a part may be printed utilizing an apparatus 100 and then automatically transferred (via, e.g., a conveyor belt, robotic handler, or similar system) to a finishing station (e.g., rock tumbler, vibration box, bead blasting cabinet, etc.) and thence to a cleaning station for automatic sterilization with UV light, chemicals, etc. The part may then be transferred into, e.g., a plastic wrap station, and then to a packaging station with an automatic labeler that labels the boxed parts as they exit. A parallel assembly line may produce packing material for the printed part. For example, a mold of the printed part may be utilized to shape packaging foam such that it is form-fitted to the finished part. The shaped foam may be fed into the packaging system along with a box in the main assembly line.
[0077] In accordance with various embodiments of the invention, wire-tracking systems such as wire-tracking systems 600 , 700 , as well as rafts (e.g., raft 900 ) and/or other portions of apparatus 100 may be utilized with wires composed of non-metallic materials (e.g., plastic) and/or to print non-metallic (e.g., plastic) objects.
[0078] The terms and expressions employed herein are used as terms and expressions of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof. In addition, having described certain embodiments of the invention, it will be apparent to those of ordinary skill in the art that other embodiments incorporating the concepts disclosed herein may be used without departing from the spirit and scope of the invention. Accordingly, the described embodiments are to be considered in all respects as only illustrative and not restrictive.
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In various embodiments, a three-dimensional metallic structure is fabricated in layer-by-layer fashion via deposition of discrete metal particles resulting from the passing of an electric current between a metal wire and an electrically conductive base or a previously deposited layer of particles.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
REFERENCE TO SEQUENCE LISTING
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention is related to an apparatus for use with a swimming pool; and more specifically, to a pool pillow or bladder for raising or lifting and supporting a pool cover.
[0006] 2. Description of Related Art
[0007] In northern climates, during the winter months of the year when swimming pools are not in use, many pool owners use a cover. The cover helps to keep debris out of the pool making spring cleaning easier. Conventional swimming pool covers are typically a flexible and impervious plastic sheet or tarp placed over the pool. Depending upon the type of pool or pool configuration, the cover is adhered to the ground or in the case of pools with decks water tubes or bags are often placed on the surrounding deck on top of the cover to hold the cover in place.
[0008] Usually the cover rests below the peripheral edge or deck of the pool and on the surface of the pool water. Accordingly, leaves, sticks and other debris along with standing water collects on the cover during the course of the winter and must be removed in early spring prior to taking the cover off and opening the pool. Typically, great care needs to be taken when removing the cover to avoid dirty water and debris collected on top of the cover from draining into the pool. Removal often includes using a small pump to pump any standing water off the cover and then removing the cover with the debris located thereon. In many cases, leaves or other debris mixes with the water on the cover and clogs the pump making cleanup and uncovering the pool much more difficult.
[0009] Many different designs and systems have been employed in an attempt to prevent water and debris from collecting on the cover. One example of such a pool cover is illustrated in U.S. Pat. No. 3,600,721 to Pusey. Pusey discloses a cover formed of a sheet of impervious material supported on its periphery by a raised inflatable tubular segment. The cover is free-floating and unattached to the pool sides but fits snugly against the pool sides to provide protection against dirt and debris entering the pool.
[0010] U.S. Pat. No. 4,685,254 to Terreri discloses a swimming pool cover support and method of covering a pool using an inflatable balloon to elevate the center of the cover to prevent accumulation of debris on the cover.
[0011] U.S. Pat. No. 4,825,479 to Bonneau discloses an inflatable swimming pool cover. The cover is impervious to air and has a skirt that extends into the water. Air pumped into the space between the cover and the surface of the water inflates and raises the cover to an arched configuration such that the cover floats on a cushion of air. A plurality of elastic cables secure the cover to the swimming pool.
[0012] U.S. Pat. No. 6,539,559 to Creech et al. discloses an anti-litter float or balloon for a swimming pool. The balloon continuously abuts the containing wall and prevents litter from being dispersed into the pool water. Flaps or other element resistant covers can be used for mooring the balloon to batten down the pool.
[0013] U.S. Pat. No. 6,694,539 to Kordell et al. discloses a pool cover that has a centrally located bubble and a series of inflatable branches connected to the centrally located bubble. The bubble is inflatable as well as the branches, which serve as a framework. A series of cover sections are located between the series of branches. The branches also serve as a means to removably tie down or attach the pool cover to the pool structure or adjacent securing objects.
[0014] A problem with using the prior art is that an air gap exists below the cover and above the water surface. Such a gap allows the cover to flap or vibrate on windy days. One way to reduce such vibration is to keep the cover taut; however, this results in additional problems in attempts and methods to anchor or hold the cover in place. Such systems often result in the use of heavier and stronger covers needed to support the anchor. Further, depending upon the geographic location, snowfall in colder climates can cause the cover to collapse as the weight may cause the balloon to burst or compress. Accordingly, to address these issues, the pool cover is typically arranged such that it lies on the surface of the water and located below the peripheral edge of the poolside whereby dirt and debris collect on the pool cover.
SUMMARY OF THE INVENTION
[0015] According to a preferred embodiment of the invention, there is provided an apparatus for use with a swimming pool cover. The apparatus includes a support member, a bladder attached to the support member and a conduit connected to and extending from the bladder with the conduit configured for bidirectional fluid flow used to inflate and deflate the bladder.
[0016] In a further embodiment of the invention, the support member is buoyant and floats or rests on the surface of the water located in the swimming pool. The support member further operates to hold the bladder in position.
[0017] An additional embodiment of the invention includes a method for covering and uncovering a swimming pool. The method including placing an apparatus having a buoyant support member and an inflatable bladder underneath a swimming pool cover with the bladder in a deflated position. The bladder is inflated to raise the swimming pool cover to a level above an upper edge of the pool periphery whereby any debris located on the pool cover falls or can be rinsed off or removed prior to removing the cover.
[0018] Accordingly, it is an object of the present invention to provide an apparatus and method enabling removal of a pool cover without allowing water and debris located on top of the cover from entering the pool.
[0019] These objects and other features, aspects and advantages of this invention will be more apparent after a reading of the following detailed description, appended claims and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view of an apparatus for use with a swimming pool cover according to an embodiment of the present invention.
[0021] FIG. 2 is a side sectional view of the apparatus for use with a swimming pool cover as illustrated in FIG. 1 .
[0022] FIG. 3 is a top view of the apparatus for use with a swimming pool cover as illustrated in FIG. 1 .
[0023] FIG. 4 is a schematic side view of an apparatus for use with a swimming pool cover according to the present invention illustrated in a deflated condition in a swimming pool.
[0024] FIG. 5 is a schematic side view of an apparatus for use with a swimming pool cover according to the present invention illustrated in an inflated condition in a swimming pool.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Turning now to FIGS. 1-3 there is shown one embodiment of an apparatus for use with a swimming pool cover, seen generally at 10 , according to the present invention. The apparatus 10 includes a support member, illustrated as an outer tube or ring 12 and an inflatable and deflatable bladder 14 . A plurality of clips 16 attach the bladder 14 to the outer tube or ring 12 . An air line 18 connects to the bladder 14 and is used to inflate or deflate the bladder 14 .
[0026] The support member 12 is buoyant and both supports and locates the bladder 14 on the water surface. Accordingly, the support member 12 has a construction or design enabling it to float on the water surface. For example, in one embodiment the support member 12 includes a hollow elongated portion. In other embodiments, the support member 12 may be an inflatable tube, a solid tube made of an expanded polystyrene material, or any other material or construction that retains its shape and floats on the surface of the water.
[0027] The bladder 14 is capable of being inflated and deflated and as such is made of a sufficiently resilient and impervious material such as rubber or vinyl. The air line 18 is connected to the bladder 14 and provides a conduit for air flow when inflating or deflating the bladder 14 . As illustrated a plurality of clips 16 are used to attach the bladder 14 to the support member 12 . In one embodiment, the clips 16 are secured to the support member 12 and engage a portion of the bladder 14 such as an ear or tab 20 . In this manner, the bladder 14 can be removed or replaced as needed. Further, while shown separate from the support member 12 , and attached by clips 16 , the bladder 14 can be made integral with the support member 12 . For example, a circumferential bead or welt could divide a single member into two sections with one being the support member 12 and the other section being the bladder 14 .
[0028] In keeping with the present invention, the support member 12 while shown in the instant embodiment as a circular, closed shape, annular member the support member 12 can be shaped depending upon the pool design. For example, the support member 12 may include a plurality of its spaced apart sections joined by connecting members. As illustrated, the support member 12 defines an interior opening in which the bladder 14 is located. Depending upon the design, the bladder 14 may also be located outside the support member 12 as opposed to positioned in the interior opening. With the size of the support member 12 being such that it is typically spaced two to three feet from the peripheral edge of the pool. Accordingly, for a rectangular pool, the support member 12 will typically have a rectangular shape wherein the bladder 14 has a similar rectangular shape or it may have a different shape.
[0029] Turning to FIGS. 4-5 , there is shown a schematic representation of an apparatus 10 in use with a swimming pool cover 30 . As illustrated in FIG. 4 , the apparatus 10 , with the bladder 14 in the deflated condition is placed in the pool 22 with the support member 12 . The bladder 14 , in a deflated condition, floats on the water which is typically below the top surface of the deck or railing 26 . The outer top periphery of the support member 12 , when floating on the water is above the deck or railing 26 . The apparatus 10 is typically located on the water surface 24 such that it is equally spaced from the inner peripheral edge 28 of the pool 22 . Spacers or support lines, cables or other members can be used for this purpose. Once the apparatus 10 is located in the pool 22 , the pool cover 30 is placed over the pool 22 and secured to the pool 22 . As shown in FIG. 4 , the pool cover 30 may (if it has accumulated water on the top surface of the pool cover 30 ) rest on the water surface 24 and will contact the upper most periphery of the support member 12 of the apparatus 10 which extends above the deck or railing 26 . In this manner gaps between the pool cover 30 and the water surface 24 are minimized, thereby minimizing lifting, vibration and flapping of the pool cover 30 . In the configuration illustrated in FIG. 4 , over time water, snow, dirt and debris may accumulate on the pool cover 30 . During installation it may be desired to inflate the bladder 14 to help place the pool cover 30 on the pool 22 and center the apparatus 10 . Once the pool cover 30 is in place, the bladder 14 can then be deflated.
[0030] When it is desired to remove the pool cover 30 from the pool 22 , the bladder 14 is inflated to the position shown in FIG. 5 . To inflate the bladder 14 , air from a suitable source such as a portable air pump (not shown) is supplied through the air line 18 to the bladder 14 . Inflation of the bladder 14 continues until it lifts the pool cover 30 to a height above the deck or railing 26 of the pool 22 whereby any water, dirt or debris remaining on the pool cover 30 either runs off or may be washed off with a garden hose. Further, to the extent a large amount of water remains on the pool cover 30 inflation of the bladder 14 causes the water to congregate near the inner peripheral edge 28 adjacent the deck or railing 26 where it can easily be pumped off. Once a suitable amount of water located on the pool cover 30 is removed, the entire pool cover 30 can be raised above the deck or railing 26 of the pool 22 and sprayed off with a garden hose, after which the pool cover 30 can be removed without dirt or debris falling from the pool cover 30 into the pool 22 .
[0031] Accordingly, the present invention provides an apparatus 10 that is disposed under the pool cover 30 and operates to lift the pool cover 30 prior to removal thereof to assist in the removal of any dirt and debris or standing water left on the pool cover 30 . While shown with a standard pool cover 30 , typically a sheet of a polypropylene, polyester or vinyl material, especially those that are impervious and require that any standing water be pumped off the pool cover 30 , the apparatus 10 can be used with any type of pool cover 30 .
[0032] It should be understood that in some instances the bladder 14 may be fully or partially inflated to support the pool cover 30 during the entire time the pool cover 30 is located on the pool 22 . In these instances, the apparatus 10 self centers and raises the pool cover 30 thereby reducing any accumulation of dirt, debris or standing water on the pool cover 30 .
[0033] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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An apparatus and method used in conjunction with a swimming pool cover for covering and uncovering a swimming pool to reduce or prevent standing water, dirt or debris from entering the pool when uncovering the pool. The apparatus includes a buoyant support member, and inflatable/deflatable bladder attached to the support member and a conduit for providing a fluid used to inflate and deflate the bladder. In operation, inflation of the bladder raises the pool cover above the pool deck, railing or peripheral edge whereby standing water, dirt or debris can be removed or washed from the cover prior to removing the cover from the pool.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to providing computerized simulations of real-world views. In particular, the present invention is directed towards a sensor and display-independent quantitative per-pixel stimulation system.
[0003] 2. Description of the Related Art
[0004] Pilots of aircrafts or other pilot-controlled vehicles sometimes guide their aircraft over a given terrain with the assistance of vision-augmenting equipment known as sensors, including, for example, Night Vision Goggles (NVG's) and Low Level Light Television Cameras (LLLTV's). Sensors typically are used to convert hard-to-see imagery in one or more of the visible and/or invisible spectral bands into imagery that is more clearly visible to the human eye. Sensors often display imagery that is different from the one a pilot may be accustomed to seeing naturally with his or her own eyes (also known as an out-the-window view). Therefore, it is desirable to train pilots ahead of time so that they can correctly interpret what they see with sensors during actual flights.
[0005] Flight simulators are commonly used to simulate flight training environments. Flight simulators typically include one or more video display screens onto which video images are projected by one or more projectors. Two known approaches are used in pilot training: simulation systems and stimulation systems.
[0006] Simulation systems display images as they would appear to a pilot using a given sensor. For example, if NVGs are being simulated, the display shows an image on a head-mounted display as it might appear to a pilot wearing NVGs. Since the displayed image already incorporates the wavelength translations performed by the sensor—i.e. the system displays simulated images—these types of systems do not allow the pilot to use actual vision-augmenting equipment during training. This is considered a drawback of simulated systems, because a pilot's experience using the simulator will differ from that during actual flight-for example, wearing NVGs, a pilot may see a sensor-based image occupying most of his field of vision, but may see a regular out-the-window image using his peripheral vision. Since in a simulated system only a sensor-adjusted image is displayed, and is based on head tracking, the experience differs from that of the real world. The disparity between the simulator and the real world experience is further augmented by the pilot not being able to wear the sensor equipment.
[0007] Stimulated systems, on the other hand, provide a pilot with a stimulated image that can be viewed using an appropriate sensor, e.g., one that can be worn by the pilot. Again using the example of NVGs, with a stimulated system the images displayed will match the spectral wavelengths to which the NVGs are sensitive, allowing the pilot to use a real pair of NVGs and thus provide a more realistic experience. However, because display systems vary widely in their display characteristics, the spectra emitted by one system might appear drastically different than those emitted by a second system, and the real world image different still. Accordingly, stimulated systems are generally of lower fidelity than simulated systems, providing only a qualitative experience versus the more quantitative experience of simulated systems.
[0008] Accordingly, what is needed is a system and method for providing high-quality stimulated imaging.
SUMMARY OF THE INVENTION
[0009] The present invention enables a sensor-independent per-pixel stimulating spectral method and apparatus that is configurable across different display systems and which combines quantitative simulated sensor rendering with a stimulated system.
[0010] Initially, a display system to be used with a system of the present invention is characterized according to the particulars of its emissions. An image generator (IG) generates a test pattern that is then displayed by the display system to be characterized. A spectroradiometer measures radiant power emanating from the display and stores the data. The process is repeated for various combinations of test pattern images—for example, for a color-independent RGB display, each value of red, each value of green, and each value of blue is measured.
[0011] Once the display has been characterized (also known as calibrated), the present invention creates color lookup tables that map simulated luminance to stimulating color values. This mapping is specific to the display that has been characterized and to the sensor that will be used with the display.
[0012] Once the display has been characterized and the color lookup tables created, the present invention is ready to be used for flight (or other) simulation. A simulated image stream is received by the present invention, and using the color lookup tables, for each luminance value provided in the stream, a set of RGB values (or other input values, depending on the display technology involved) is determined that will produce the equivalent stimulated image on the display system. Those color values are then provided to the display system by the IG, and displayed for use with the appropriate sensor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 illustrates a method for performing sensor and display-independent sensor stimulation in accordance with an embodiment of the present invention.
[0014] FIG. 2 illustrates a system for providing stimulated images in accordance with an embodiment of the present invention.
[0015] FIG. 3 is a block diagram illustrating a display characterization function in accordance with an embodiment of the present invention.
[0016] FIG. 4 illustrates a method for automatic display calibration in accordance with an embodiment of the present invention.
[0017] FIG. 5 illustrates an example spectral radiance graph in accordance with an embodiment of the present invention.
[0018] The figures depict preferred embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] FIG. 1 illustrates three steps of a method for performing sensor and display-independent sensor stimulation. First, the display system that will be used in conjunction with the sensor is characterized 102 according to the particulars of its emissions. Next, sensor-dependent color lookup tables that map simulated luminance to stimulating color values are created 104 . This mapping is specific to the display that has been characterized and to the sensor that will be used with the display. Finally, a simulated image stream is received by the present invention, and using the color lookup tables, for each luminance value provided in the stream, a set of RGB values (or other input values, depending on the display technology involved) is determined 106 that will produce the equivalent stimulated image on the display system. Those color values are then provided to the display system for use with the appropriate sensor. Each of these steps is described further below.
[0000] System Architecture
[0020] FIG. 2 illustrates a system 200 for providing stimulated images in accordance with an embodiment of the present invention. System 200 includes an image generator (IG) 202 and its calibration engine 206 , a simulator engine 204 , and color lookup tables 208 . Each of these components is further described below. FIG. 2 also includes a simulated data stream 210 , a display system 212 , a sensor 214 , and a pilot 216 , meant to represent a user of system 200 .
[0000] Calibration
[0021] Because each display system has its own particular characteristics, the exact spectral emissions from the display system will vary between systems receiving the same input. Indeed, even a single display system may develop different characteristics over time, for example as the projector ages. Consequently, it is preferable to first calibrate system 200 for use with a particular display system 212 .
[0022] FIG. 3 illustrates a way in which display characterization is preferably performed. Image generator 202 creates or displays a color video image assigned to a given color or video level. For display calibration, image generator 202 preferably includes a test pattern generator. IG 202 sends images for display to display system 212 . Display system 212 is a monitor, screen, video projector, rear projector, dome, or any other device adapted to display an image. During display calibration, display system 212 receives images from IG 202 and displays the images. The display is then measured by a spectroradiometer 330 . That is, the radiant power or energy per wavelength emanating from display system 212 is measured by the spectroradiometer 330 . In one embodiment, spectroradiometer 330 is the PR-715 spectroradiometer, by Photo Research Inc. of Chatsworth, Calif.; in an alternative embodiment, spectroradiometer 330 is the Minolta R-1000 by Konica Minolta of Japan. Spectroradiometer 330 returns the results of its measurements to IG 202 , which stores the data sets, e.g., in database 304 .
[0023] The result of the display calibration is a series of power spectral tables or datasets for each measured color video level, or for each of the display input levels.
[0024] FIG. 4 is a trace diagram of a method for automatic display calibration performed by system 200 in accordance with one embodiment of the present invention. Initially, at step 400 , calibration engine 206 sets intensity values for red, green and blue to a minimum value, e.g., 0 intensity. IG 202 generates 410 an image such as a test pattern and sends it to display system 212 , which then displays 490 the image. A test pattern in a preferred embodiment corresponds to specified red, green and blue values. The example of FIG. 4 illustrates the case in which initially only red values are displayed, and then green and then blue data values are added in as described below. Calibration engine 206 next activates 412 spectroradiometer 330 to perform spectral measurements. Spectroradiometer 330 measures 492 emissions from display system 412 and sends 420 the measurements back to calibration engine 206 . Assuming for purposes of the illustrated example that there are 256 possible values of red intensity, calibration engine 206 increments 430 the value (intensity) of the image being displayed by a delta amount. If 440 the new red-value does not exceed a maximum red value, the process returns to step 410 and the image with the new red value is then measured by spectroradiometer 330 . Once all of the red intensity values have been measured, the red intensity value is reset 450 to its original value, and values are then measured for each green intensity value (i.e. for each intensity value of green, 256 values of red intensity are measured). Once 460 the value of green intensity reaches its maximum, blue values are then measured 470 for each intensity value of red and green. At the conclusion of all steps, emissions for intensity values for each combination of red, green and blue have been measured and stored by calibration engine 206 . In this example, 256×256×256=16,777,216 measurements.
[0025] In an alternative embodiment using display systems that feature true color independence, such as on CRT RGB video projectors, the number of measurements taken can be reduced. Because of their color independence, there is no need to measure all color parameter combinations—only the independent values of each color. In the case of RGB color parametric space, if 256 levels are used, only 256+256+256=768 measurements will be required, compared the 16,777,216 measurements required when a display system lacks color independence.
[0026] FIG. 5 illustrates an example spectral radiance graph 500 for a measurement taken with a red value of 255, and blue and green values of 0 each.
[0000] Color Lookup Table Determination
[0027] System 200 uses color lookup tables 208 to map simulated luminance to stimulating color values. That is, color lookup tables 208 indicate for a particular simulated luminance that is part of simulated data stream 210 what corresponding color values of a stimulated image would produce that simulated luminance given a particular sensor and a particular display device. Once the stimulated color values are known they can be sent by image generator 202 to display system 212 and viewed by pilot 216 using sensor 214 .
[0028] As is known by those of skill in the art, a sensor 214 such as NVGs enables increased perception of the environment by amplifying and translating the wavelengths captured by the sensor. A particular sensor has a spectral response that is characteristic of that sensor and can be determined experimentally using methods known to those of skill in the art, or obtained from the manufacturer of the sensor. The spectral response of the sensor is the response of the sensor to a power at a given wavelength (or range of wavelengths).
[0029] Thus, simulator engine 204 constructs a color lookup table by iterating through the various color value combinations, e.g., RGB values from 0 to 255. For each color value, simulator engine 204 determines the actual image that would be displayed by the particular display system 212 , and the stimulated luminance value that would be produced by the sensor from the displayed image values. Performing this step for each color value and then sorting by resulting luminance provides a color lookup table 208 that system 200 then can use to map from a luminance value to a color value set that can be used with the specified sensor on the calibrated display system.
[0030] In an alternative embodiment, luminance values that result in deviant colors—i.e. those colors that vary substantially from grayscale values—are excluded from the lookup table. This has the effect of producing images that while still stimulating the sensor create less distracting colors for an observer not wearing a sensor such as NVGs, as well as being less distracting through peripheral vision of an observer who is wearing a sensor like NVGs, which only covers a subset of the field of view. This takes advantage of the fact that unaided human vision at night or at low light levels is not very perceptive of small color deviations from gray scale.
[0000] Run-Time Operation
[0031] System 200 uses color lookup table 208 to render pixels or texels appropriate to the display system 212 and sensor 214 in use in the simulator. Simulator engine 204 takes as input a simulated data stream 210 provided by conventional real-time sensor simulation software or hardware, determines a corresponding stimulating color value set by referring to color lookup table 208 , and generates an image using IG 202 that is then displayed by display system 212 . Because the color lookup table 208 is specific to the display system 212 in use as well as to the sensor in use, the stimulated image generated by IG 202 will look to a pilot 216 using sensor 214 and display system 212 essentially identical to the simulated image originally provided by the simulated stream 210 . However, because the image is stimulated instead of simulated, the pilot has the advantage of being able to participate in a much more real-world simulation, e.g., by wearing NVGs that correctly account for peripheral vision effects, head motion, and the like—and because the stimulated image is accurate for the display system and the sensor in use, the lack of fidelity that previously plagued stimulated image systems is not present when using system 200 .
[0032] The present invention has been described in particular detail with respect to a limited number of embodiments. Those of skill in the art will appreciate that the invention may additionally be practiced in other embodiments. First, the particular naming of the components, capitalization of terms, the attributes, data structures, or any other programming or structural aspect is not mandatory or significant, and the mechanisms that implement the invention or its features may have different names, formats, or protocols. Further, the system may be implemented via a combination of hardware and software, as described, or entirely in hardware elements. Also, the particular division of functionality between the various system components described herein is merely exemplary, and not mandatory; functions performed by a single system component may instead be performed by multiple components, and functions performed by multiple components may instead performed by a single component. For example, the particular functions of the image generator and so forth may be provided in many or one module.
[0033] Some portions of the above description present the feature of the present invention in terms of algorithms and symbolic representations of operations on information. These algorithmic descriptions and representations are the means used by those skilled in the art of sensor simulation to most effectively convey the substance of their work to others skilled in the art. These operations, while described functionally or logically, are understood to be implemented by computer programs. Furthermore, it has also proven convenient at times, to refer to these arrangements of operations as modules or code devices, without loss of generality.
[0034] It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the present discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system memories or registers or other such information storage, transmission or display devices.
[0035] Certain aspects of the present invention include process steps and instructions described herein in the form of an algorithm. It should be noted that the process steps and instructions of the present invention could be embodied in software, firmware or hardware, and when embodied in software, could be downloaded to reside on and be operated from different platforms used by real time network operating systems.
[0036] The present invention also relates to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, application specific integrated circuits (ASICs), or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus. Furthermore, the computers referred to in the specification may include a single processor or may be architectures employing multiple processor designs for increased computing capability.
[0037] The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may also be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will appear from the description above. In addition, the present invention is not described with reference to any particular programming language. It is appreciated that a variety of programming languages may be used to implement the teachings of the present invention as described herein, and any references to specific languages are provided for disclosure of enablement and best mode of the present invention.
[0038] Finally, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention.
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Sensor independent display characterization system spectrally characterizes a display system to measure radiant power emitted by the display system that displays a video image to a trainee pilot during sensor stimulation. A sensor spectral response for each wavelength produced by the stimulated sensor is determined. A stimulated luminance for each color level of the displayed image or for a range of color levels is computed. A color look up table that maps computed stimulated luminance to a set of stimulating color values is generated. When a trainee pilot looks at the displayed image using a sensor having a sensor response that was used in computing the stimulated luminance, the pilot will see an image that was created by simulated spectral rendering. The displayed image is an accurate, display and sensor independent image that the pilot can see during the real flight.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates a display device using organic electroluminescence elements, light-emitting diodes or other similarly light-emitting elements. More particularly, the present invention relates to a display device having a driving circuit which can suppresses changes of light emission intensity of the light emitting elements.
[0003] 2. Description of the Related Art
[0004] Display devices are known employing for example organic EL (electroluminescence) elements. Organic EL elements can be driven with low DC voltage. In addition, organic EL elements are light-emitting elements, so, compared with optically transparent elements such as liquid-crystal elements, they provide a wide field of view angle, a bright display surface and are of small thickness and light weight. Organic EL elements can therefore be employed as large-capacity display devices for various applications.
[0005] A technique for driving organic EL display devices is disclosed in for example Japanese Laid-open publication number 301355/1994.
[0006] The electrical characteristic of an organic EL element is disclosed in FIG. 7 of this publication. An organic EL element emits light when current flows in the forward direction between the anode and cathode. However, the light emission intensity of an organic EL element depends not merely on the current between the anode and cathode but also on the voltage between the anode and cathode. Consequently, in order to match the light emission intensity of the organic EL element accurately with the design value, it is necessary to control both the current and the voltage between the anode and cathode.
[0007] An organic EL display device comprises a large number of organic EL elements arranged in matrix fashion. With such a construction, when a large number of organic EL elements emit light simultaneously, the amount of current flowing to ground becomes very large. The cathode potential of the organic EL elements therefore rises, due to the internal resistance of the drive circuit. Consequently, the voltage between the anode and cathode of the individual organic EL elements is decreased. That is, the light emission intensity of the individual organic EL elements may be lowered due to a large number of organic EL elements emitting light simultaneously.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide a display device wherein the change of the amount of light of the light-emitting elements caused by change of the number of light-emitting elements that emit light simultaneously is small.
[0009] For this purpose, a display device according to the present invention comprises: a display panel comprising light-emitting elements arranged in matrix fashion; a plurality of data lines that apply anode potential to light-emitting elements of the same column; a plurality of scanning lines that apply cathode potential to light-emitting elements of the same row; and a control circuit that adjusts the voltage between the anode and cathode of the light-emitting elements in accordance with the number of light-emitting elements that emit light simultaneously.
[0010] The control circuit suppresses change of the voltage between the anode and cathode of the light-emitting elements caused by change of the number of light-emitting elements that emit light simultaneously. In this way, change of the amount of light of the light-emitting elements is suppressed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Other objects and advantages of the present invention will be described with reference to the appended drawings.
[0012] [0012]FIG. 1A is a circuit diagram illustrating the overall layout of a display device according to a first embodiment;
[0013] [0013]FIG. 1B is a circuit diagram illustrating an example layout of a positive electrode output circuit illustrated in FIG. 1A;
[0014] [0014]FIG. 1C is a circuit diagram illustrating an example layout of a negative electrode output circuit illustrated in FIG. 1A;
[0015] [0015]FIG. 2 is a diagram given in explanation of the operation of a drive circuit according to a first embodiment;
[0016] [0016]FIG. 3A is a circuit diagram illustrating the overall layout of a display device according to a second embodiment;
[0017] [0017]FIG. 3B is a circuit diagram illustrating an example layout of a positive electrode output circuit illustrated in FIG. 3A;
[0018] [0018]FIG. 4A is a circuit diagram illustrating the overall layout of a display device according to a third embodiment; and
[0019] [0019]FIG. 4B is a circuit diagram illustrating an example layout of a positive electrode output circuit illustrated in FIG. 4A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Embodiments of the present invention are described below with reference to the drawings. In the drawings, the size of the various constituent components, their shape and arrangement relationships are shown only diagrammatically to a degree such as to enable the present invention to be understood; also, numerical conditions described below are given merely by way of example.
[0021] First Embodiment
[0022] [0022]FIG. 1A to FIG. 1C are circuit diagrams illustrating the layout of a display device according to a first embodiment of the present invention.
[0023] As shown in FIG. 1A, this matrix type display device comprises a display panel 100 , a shift register 110 , AND gate 120 , display number counter 130 , address decoder 140 , display data RAM (random access memory) 150 , negative electrode control RAM 160 , positive electrode output circuits 170 - 1 to 170 -n and negative electrode output circuits 180 - 1 to 180 -n.
[0024] Display panel 100 comprises n×n (for example 128×128) organic EL elements EL 11 to ELnn, data lines SEG 1 to SEGn and scanning lines COM 1 to COMn. EL elements of the same column are connected with the same data line. Also, EL elements of the same row are connected with the same scanning line.
[0025] Shift register 110 inputs serial display data DA with a timing supplied by clock CK and converts the data DA into n-bit parallel signals. In the display data of the present embodiment, high-level indicates “ignited” and low-level indicates “not ignited”.
[0026] AND gate 120 inputs the display data DA and clock signal CK, and outputs the logical product of these signals.
[0027] Display number counter 130 inputs the output signal of AND gate 120 and counts the number of high-level signals. The count result is output. The output count value indicates the number of “ignited” data items in the display data of a single row.
[0028] Address decoder 140 outputs for example a 64-bit address signal A to display data RAM 150 and negative electrode control RAM 160 . Address signal A is employed as the write address and read address of RAM 150 and 160 .
[0029] Display data RAM 150 stores the display data DA that is input from shift register 110 . In addition, display data RAM 150 outputs the bits of the storage data to positive electrode output circuits 170 - 1 to 170 -n.
[0030] Negative electrode control RAM 160 stores the count value of display number counter 130 . Also, negative electrode control RAM 160 generates a negative electrode control signal using this stored value and outputs this to negative electrode output circuits 180 - 1 to 180 -n. 3-bit negative electrode control signals are supplied to each of the negative electrode output circuits 180 - 1 to 180 -n. The negative electrode control signals SK 1 , SK 2 , SK 3 that are supplied to negative electrode output circuits 180 - 1 are shown in FIG. 1. There are no particular restrictions on the method of determining the value of the negative electrode control signal. In this embodiment, when the count value is 1 to 32, only signal SK 1 is high-level; when the count value is 33 to 64, only signal SK 2 is high-level; and when the count value is 65 or more, only signal SK 3 is made high-level. With this method, negative electrode control signals SK 1 , SK 2 and SK 3 can be generated using only the most higher three bits of the count value. The negative electrode output circuits that are not selected are supplied with low-level negative electrode control signals which are also 3-bit.
[0031] Positive electrode output circuits 170 - 1 to 170 -n input display data of corresponding bits from display data RAM 150 . The bits of the display data DA are subjected to inverted value/DA conversion when they are written to RAM 150 , before being input to positive electrode output circuits 170 - 1 to 170 -n. Positive electrode output circuits 170 - 1 to 170 -n output potentials corresponding to the values of the display data DA to the corresponding data lines to SEG 1 to SEGn. As shown in FIG. 1B, positive electrode output circuit 170 - 1 comprises a constant-current element 171 , a pMOS transistor 172 and an nMOS transistor 173 . Constant-current element 171 inputs power source voltage Vs (for example 20 volt) being supplied for the data line and outputs a constant current. Constant-current element 171 is constituted by for example an MOS transistor of fixed gate potential. pMOS transistor 172 is connected at its source to the output of constant-current element 171 , is connected at its drain to data line SEG 1 and is connected at its gate with the lowest bit of display data RAM 150 . Also, nMOS transistor 173 is connected at its source with the ground line, is connected at its drain with data line SEG 1 and is connected at its gate with the lowest bit of display data RAM 150 . Consequently, when the input display data/DA is low-level, positive electrode output circuit 170 - 1 outputs a prescribed high level voltage and when the input display data/DA is high-level potential outputs a prescribed low-level potential i.e. zero volts. The construction of the other positive electrode output circuits 170 - 2 to 170 -n is the same as the construction of positive electrode output circuit 170 - 1 .
[0032] The negative electrode output circuits 180 - 1 to 180 -n discharge the current that is input from the cathodes of organic EL elements EL 11 to ELnn through scanning lines COM 1 to COMn to the ground line. The negative electrode output circuit 180 - 1 corresponding to scanning line COM 1 adjusts the cathode potential of organic EL elements EL 11 to Eln 1 in accordance with the signals SK 1 , SK 2 and SK 3 that are input from negative electrode control RAM 160 . As shown in FIG. 1C, negative electrode output circuit 180 - 1 comprises an OR gate 181 , pMOS transistor 182 and three nMOS transistors 183 - 1 , 183 - 2 and 183 - 3 . OR gate 181 outputs the logical sum of signals SK 1 , SK 2 and SK 3 . pMOS transistor 182 is connected at its source with power source Vc being supplied for the scanning line (for example 20 volt), is connected at its drain with scanning line COM 1 and is connected at its gate with the output of OR gate 181 . nMOS transistor 183 - 1 is connected at its source with the ground line, is connected at its drain with scanning line COM 1 and inputs signal SK 1 from its gate. nMOS transistor 183 - 2 is connected at its source with the ground line and at its drain is connected with scanning line COM 1 and inputs signal SK 2 from its gate. nMOS transistor 183 - 3 is connected at its source with the ground line, is connected at its drain with scanning line COM 1 and inputs signal SK 3 from its gate. The ratios of the ON resistances of nMOS transistors 183 - 1 , 183 - 2 , 183 - 3 may be selected at will. In this embodiment, the ratios of the ON resistances of nMOS transistors 183 - 1 , 183 - 2 and 183 - 3 are set to 4:2:1. The ratios of the ON resistances can be set by the gate widths of nMOS transistors 183 - 1 , 183 - 2 , and 183 - 3 , for example. The constructions of the other negative electrode output circuits 180 - 2 to 180 -n are the same as the construction of negative electrode output circuit 180 - 1 .
[0033] Next, the principles of operation of a display device according to this embodiment will be described using FIG. 1A to FIG. 1C and FIG. 2. Hereinbelow, the case where n=128 will be described by way of example.
[0034] [0034]FIG. 2 is a concept diagram given in explanation of the operation of the display device illustrated in FIG. 1A to FIG. 1C.
[0035] First of all, the operation of reading display data DA will be described.
[0036] Display data DA is input to shift register 110 from outside in serial form synchronized with clock CK. The input display data DA is converted to data corresponding to one row worth of data, namely 128-bit parallel data. Simultaneously, display data DA in serial form and clock CK are also input to AND gate 120 . The output of AND gate 120 is input to display number counter 130 . As a result, the display number counter 130 counts the number of “ignition” data contained in one row of display data DA. The converted display data DA is sequentially stored in display data RAM 150 and the count value is simultaneously stored in negative electrode control RAM 160 . The storage position of the display data and the storage position of the count value are determined in accordance with the address signal A that is output from address decoder 140 .
[0037] Next, the operation of displaying the first row of display panel 100 will be described. The operation of displaying the second and subsequent rows of display panel 100 is the same as in the case of the first row.
[0038] Address decoder 140 outputs an address signal A corresponding to the display data of the first row. This address signal A is input to RAM 150 and 160 . Display data RAM 150 outputs of 128-bit data/DA (i.e. the inverted value of the display data DA) corresponding to the address signal A to positive electrode output circuits 170 - 1 to 170 -n. Also, negative electrode control RAM 160 outputs negative electrode control signals SK 1 , SK 2 and SK 3 to negative electrode output circuit 180 - 1 .
[0039] Positive electrode output circuits 170 - 1 to 170 -n (n=128) input the corresponding bits of data/DA. As described above, positive electrode output circuits 170 - 1 to 170 -n output high level when data/DA is low level and output low level when the bit signal is high-level (see FIG. 1B) . The outputs of positive electrode output circuits 170 - 1 to 170 -n are applied to the anodes of the organic EL elements EL 11 , EL 21 , . . . , ELnn through data lines SEG 1 to SEGn.
[0040] Negative electrode output circuit 180 - 1 inputs negative electrode control signals SK 1 , SK 2 and SK 3 . pMOS transistor 182 turns OFF when any of negative electrode control signals SK 1 , SK 2 and SK 3 is high-level. Also, nMOS transistor 183 - 1 turns ON when signal SK 1 is high-level, nMOS transistor 183 - 1 turns ON when signal SK 2 is high-level and nMOS transistor 183 - 3 turns ON when signal SK 3 is high-level. Low-level potential (ground potential) is therefore applied through scanning line COM 1 to the cathodes of organic EL elements EL 11 , EL 21 , . . . , ELn 1 of the first row.
[0041] As a result, forward voltage is applied to the organic EL elements whose anodes have high-level potential applied to them while the voltage between the anode and cathode of organic EL elements which have low-level potential applied to their anodes is zero volts. For example, when positive electrode output circuit 170 - 1 is outputting high level and the other positive electrode output circuits 170 - 2 to 170 -n are outputting low level, organic EL element EL 11 , since forward voltage is being applied thereto, emits light, but the other organic EL elements do not emit light (see FIG. 2).
[0042] As described above, when the number of organic EL elements that are simultaneously ON is 1 to 32, only signal SK 1 is high-level; when the number is 33 to 64, only signal SK 2 is high-level; when it is 65 or more, only signal SK 3 is high-level. Consequently, when the number of organic EL elements that are simultaneously ON is 1 to 32, only nMOS transistor 173 is turned ON; when the number is 33 to 64, only nMOS transistor 174 is turned ON; when it is 65 or more, only nMOS transistor 175 is turned ON. Also, as described above, the ratios of the ON resistances of nMOS transistors 183 - 1 , 183 - 2 and 183 - 3 are set to 4:2:1. Consequently, if the ON resistance of an nMOS transistor is taken as R, the resistance of negative electrode output circuit 180 - 1 when the number of organic EL elements that are ON is 1 to 32 is 4R, when this number is 33 to 64 is 2R and when it is 65 or more is R.
[0043] The current that flows out to ground from scanning line COM 1 through negative electrode output circuits 180 - 1 to 180 -n becomes larger as the number of organic EL elements that are simultaneously ON is increased. As a result, if the resistance of negative electrode output circuit 180 - 1 is fixed, the amount of voltage drop of the negative electrode output circuit 180 - 1 increases as the number of organic EL elements that are simultaneously ON is increased, so the voltage between the anodes and cathode of the organic EL elements that are in the ON state becomes smaller. In contrast, with the display device of this embodiment, the resistance of negative electrode output circuit 180 - 1 becomes smaller as the number of organic EL elements that are simultaneously ON is increased. Consequently, with the display device of this embodiment, change of the voltage between the anode and cathode of the organic EL elements can be suppressed so, as a result, changes of light emission intensity of the organic EL elements can be suppressed.
[0044] In addition, this embodiment has the advantage that, since the resistance of negative electrode output circuits 180 - 1 to 180 -n is controlled using display number counter 130 and negative electrode control RAM 160 , the display device circuit layout can be simple.
[0045] In this embodiment, the resistance of negative electrode output circuits 180 - 1 to 180 -n is controlled using three nMOS transistors 183 - 1 to 183 - 3 , but four or more transistors could be employed.
[0046] Second Embodiment
[0047] [0047]FIG. 3A. and FIG. 3B are circuit diagrams illustrating the layout of a display device according to a second embodiment of the present invention. In FIG. 3A, structural elements given the same reference symbols as in FIG. 1A are respectively the same as in FIG. 1A.
[0048] As shown in FIG. 3A, a display device according to this embodiment comprises a decoder 310 . In addition, the internal construction of negative electrode output circuits 320 - 1 to 320 -n of the display device of this embodiment differs from the first embodiment.
[0049] Decoder 310 inputs a negative electrode control signal from negative electrode control RAM 160 and outputs gate control signals. Here, outputs gate control signals G 1 , G 2 , . . . , G 8 are input to the negative electrode output circuits 320 - 1 . The number of gate control signals and G 1 to G 8 which are high-level signals is determined in accordance with the value of the binary number indicated by the negative electrode control signal. For example, when the value of the negative electrode control signal is 000, only signal G 1 is set to high level; when the value of the negative electrode control signal is 001, gate control signals G 1 and G 2 are set to high level; and when the value of the negative electrode control signal is 010 the gate control signals G 1 , G 2 and G 3 are set to high level. When the value of the negative electrode control signal is 111, all of the gate control signals G 1 to G 8 are set to high level. In this embodiment, the higher three bits of the count value of the display number counter 130 are employed as the value of the negative electrode control signal. The number of high-level gate control signals therefore increases when the count value becomes larger.
[0050] The negative electrode output circuits 320 - 1 to 320 -n discharge to the ground line the current output from the cathodes of organic EL elements EL 11 to ELnn through scanning lines COM 1 to COMn. As shown in FIG. 3B, negative electrode output circuit 320 - 1 comprises an OR gate 321 , a pMOS transistor 322 , and eight nMOS transistors 323 - 1 , 323 - 2 , . . . , 323 - 8 . OR gate 321 outputs the logical sum of signals G 1 to G 8 . pMOS transistor 322 is connected at its source with power source Vc being provided to the scanning line (for example 20 volt), is connected at its drain with scanning line COM 1 and is connected at its gate with the output of OR gate 321 . nMOS transistors 323 - 1 to 323 - 8 are connected at their sources with the ground line, are connected at their drains with scanning line COM 1 and input corresponding signals G 1 to G 8 from their gates. The ON resistances of nMOS transistors 323 - 1 to 323 - 8 are the same. The constructions of the other negative electrode output circuits 320 - 2 to 320 -n are the same as the construction of negative electrode output circuit 320 - 1 .
[0051] Next, the principles of operation of a display device according to this embodiment will be described. Hereinbelow the description will be given taking as an example the case where n=128.
[0052] The operation of reading display data DA is the same as in the case of the first embodiment, so the description thereof will not be repeated.
[0053] Hereinbelow, the operation of displaying the first row of display panel 100 will be described. The operation of displaying the second and subsequent rows of display panel 100 is the same as in the case of the first row.
[0054] Address decoder 140 outputs address signal A corresponding to the display data of the first row. This address signal A is input to RAM 150 and 160 . Display data RAM 150 outputs 128-bit data/DA (i.e. the inverted value of display data DA) corresponding to address signal A to the positive electrode output circuits 170 - 1 to 170 -n. Also, negative electrode control RAM 160 outputs negative electrode control signals G 1 through G 8 to negative electrode output circuit 180 - 1 .
[0055] Positive electrode output circuits 170 - 1 to 170 -n (n=128) input the corresponding bits of the data/DA. As described above, when the data/DA is low-level, positive electrode output circuits 170 - 1 to 170 -n output high level and when the bit signal is high level output low level (see FIG. 1B). The outputs of positive electrode output circuits 170 - 1 to 170 -n are applied to the anodes of the organic EL elements EL 11 to ELnn through data lines SEG 1 to SEGn.
[0056] Decoder 310 inputs negative electrode control signals SK 1 , SK 2 and SK 3 . Also, as described above, decoder 310 makes some or all of the gate control signals G 1 to G 8 high level and makes the other gate control signals low level. In this way, the nMOS transistors corresponding to the high-level gate control signals are turned ON and the nMOS transistors corresponding to the low-level gate control signals are turned OFF. Since some or all of the nMOS transistors 323 - 1 to 323 - 8 are ON, scanning line COM 1 is low level.
[0057] As a result, forward voltage is applied to the organic EL elements which have high-level potential applied to their anodes but the voltage between the anode and cathode of the organic EL elements which have low-level potential applied to their anodes is zero volts. For example, when positive electrode output circuit 170 - 1 outputs high level and the other positive electrode output circuits 170 - 2 to 170 -n output low level, forward voltage is applied to the organic EL element EL 11 , so this emits light but the other organic EL elements do not emit light.
[0058] As described above, in this embodiment, the number of high-level gate control signals becomes larger as the count value of the display number counter 130 becomes larger. Consequently, in the-case of negative electrode output-circuit 180 - 1 , more nMOS transistors are turned ON as the count value becomes larger. The resistance of negative electrode output circuit 180 - 1 is the combined ON resistance of the nMOS transistors that are turned ON. The resistance of negative electrode output circuit 180 - 1 therefore becomes smaller as the count value is increased. With the display device of this embodiment, changes of the voltage between the anodes and cathode of the organic EL elements can therefore be suppressed and, as a result, changes in the light emission intensity of the organic EL elements EL can be suppressed.
[0059] In this embodiment, the resistance of the negative electrode output circuits 180 - 1 to 180 -n was controlled using eight nMOS transistors; however, nine or more transistors or seven or less transistor could be employed.
[0060] Third Embodiment
[0061] [0061]FIGS. 4A and 4B is a circuit diagram illustrating the construction of a display device according to a third embodiment of the present invention. In FIG. 4A structural elements that have the same reference symbols as in FIG. 1A are respectively the same as in FIG. 1A.
[0062] As shown in FIG. 4A and FIG. 4B, a display device according to this embodiment comprises a negative electrode controller 410 . Furthermore, the internal structure of the negative electrode output circuits 420 - 1 to 420 -n of the display device of this embodiment is different from that of the first embodiment.
[0063] [0063]FIG. 4B is a circuit diagram illustrating the internal structure of negative electrode controller 410 and negative electrode output circuit 420 - 1 . Only portions of the negative electrode controller 410 of FIG. 4B that are associated with negative electrode output circuit 420 - 1 are illustrated.
[0064] Negative electrode controller 410 comprises an OR gate 411 and a digital/analogue converter 412 . OR gate 411 inputs negative electrode control signals SK 1 , SK 2 and SK 3 from negative electrode control RAM 160 and outputs the logical sum of these signals as control signal CL 1 . Digital/analogue converter 412 inputs the signal values of the negative electrode control signals SK 1 to SK 3 as 3-bit binary information and outputs an analogue voltage signal CL 2 of a value corresponding to this information.
[0065] Negative electrode output circuit 420 - 1 comprises a pMOS transistor 421 and nMOS transistor 422 . pMOS transistor 421 is connected at its source with power source Vc (for example 20 volt) and is connected at its drain with scanning line COM 1 and inputs signal CL 1 from its gate. nMOS transistor 422 is connected at its source with the ground line and is connected at its drain with scanning line COM 1 and inputs signal CL 2 from its gate.
[0066] Next the principles of operation of a display device according to this embodiment will be described. Hereinbelow the case where n=128 will be taken as an example.
[0067] The operation of reading display data DA is the same as in the case of the first embodiment so the description thereof will not be repeated.
[0068] The operation of displaying the first row of display panel 100 will now be described. The operation of displaying the second and subsequent rows of display panel 100 is same as in the case of the first row.
[0069] Address decoder 140 outputs address signal A corresponding to the display data of the first row. This address signal A is input to RAM 150 and 160 . Display data RAM 150 outputs 128 bit data/DA (i.e. the inverted value of the display data DA) corresponding to address signal A to positive electrode output circuits 170 - 1 to 170 -n. Also, negative electrode control RAM 160 outputs negative electrode control signals SK 1 , SK 2 and SK 3 to negative electrode controller 410 .
[0070] Positive electrode output circuits 170 - 1 to 170 -n (n=128) output corresponding bits of the data/DA. As described above, positive electrode output circuits 170 - 1 to 170 -n output high level when data/DA is low level and output low level when the bit signal is high level (see FIG. 1B) . The outputs of positive electrode output circuits 170 - 1 to 170 -n are applied to the anodes of organic EL elements EL 11 to ELnn through data lines SEG 1 to SEGn.
[0071] Negative electrode controller 410 inputs negative electrode control signals SK 1 to SK 3 . The output CL 1 of OR gate 411 is high-level except for when all of signals SK 1 to SK 3 are zero. pMOS transistor 421 is therefore OFF. Also, digital/analogue converter 412 outputs analogue voltage CL 2 . Consequently, nMOS transistor 422 is turned ON. As a result, scanning line COM 1 becomes low-level i.e. ground potential. Consequently, in the same way as in the first embodiment described above, of the organic EL elements EL 11 , EL 21 , . . . , ELn 1 that are connected with scanning line COM 1 , the organic EL elements that are connected with high-level data lines emit light.
[0072] As described above, the value of the analogue voltage signal CL 2 changes in accordance with the values of negative electrode control signals SK 1 to SK 3 , so the ON resistance of nMOS transistor 422 changes in accordance with the values of signals SK 1 to SK 3 . Specifically, the ON resistance of nMOS transistor 422 becomes smaller as the count value of counter 130 becomes larger. Consequently, with the display device of this embodiment, changes of the voltage between the anode and cathode of the organic EL elements can be suppressed, so, as a result, changes of light emission intensity of the organic EL elements EL can be suppressed.
[0073] With the display device of this embodiment, the ON resistance of the scanning line is controlled solely by a single nMOS transistor 422 , so the number of transistors can be reduced.
[0074] In this embodiment, the negative electrode control signals were 3-bit signals, but they could be signals of four bits or more and they could be signals of two bits. The precision of control of the ON resistance can be increased as the number of bits is increased.
[0075] The number of organic EL elements of the display panel 100 is not restricted but the advantages of the present invention become more marked as the number of organic EL elements becomes larger.
[0076] In the first to the third embodiments, display panel 100 was constituted by organic EL elements, but the present invention could also be applied to display panels employing light-emitting elements of other types, for example light-emitting diodes.
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Display device wherein the change of the amount of light of the light-emitting elements caused by change of the number of light-emitting elements that emit light simultaneously is small. This display device includes: a display panel having light-emitting elements arranged in matrix fashion; data lines for applying anode potential to light-emitting elements of the same column; scanning lines for applying cathode potential to light-emitting elements of the same row; and a control circuit that adjusts the voltage between the anode and the cathode of the light-emitting elements in accordance with the number of light-emitting elements that emit light simultaneously. The control circuit suppresses changes of the voltage between the anode and the cathode of the light-emitting elements caused by a change in the number of light-emitting elements that emit light simultaneously. In this way, change of the amount of light of the light-emitting elements is suppressed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a 35 U.S.C. §371 national stage application of PCT/US2009/038520 filed Mar. 27, 2009, which claims the benefit of U.S. Provisional Patent Application No. 61/040,328 filed Mar. 28, 2008, both of which are incorporated herein by reference in their entireties for all purposes.
BACKGROUND
In subsea or other underwater well drilling procedures an established practice is to run, land, and set casing hangers and annulus packoffs in a submerged wellhead housing by means of a running tool connected to a drill string or other pipe string. The hanger is run into the wellhead using the running tool until the hanger lands on a casing hanger shoulder in the wellhead or on a previously installed hanger. The packoff is then run in and set in the annulus between the hanger and the wellhead housing the hanger running tool to form a seal between the hanger and the wellhead. The hanger and packoff are each releasably connected to the running tool and the running tool is retrievable after the hanger and packoff have been set. However, once the running tool is retrieved, the hanger and/or the packoff may not be sufficiently restrained from above, even with an additional hanger later installed. Thus, there is the possibility that even a set packoff may travel within the wellhead and potentially compromise the integrity of the seal between the hanger and the wellhead.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more detailed description of the embodiments, reference will now be made to the following accompanying drawings:
FIG. 1 is cross section view of a loading shoulder installed in a wellhead housing above a previously installed casing hanger and packoff assembly;
FIG. 2 is a cross section view of a close up of the loading shoulder of FIG. 1 ;
FIG. 3 is a cross section of a running tool and a loading shoulder being run into the wellhead housing;
FIG. 4 is a cross section view of the loading shoulder landed onto the previously installed casing hanger with the loading ring and the lock ring in the set position;
FIG. 5 is cross section view of the loading shoulder locked in position with the running tool removed;
FIG. 6 is a cross section of a casing hanger landed on the loading shoulder; and
FIG. 7 is a cross section of a packoff assembly installed on the casing hanger of FIG. 6 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
In the drawings and description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawing figures are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. The present invention is susceptible to embodiments of different forms. Specific embodiments are described in detail and are shown in the drawings, with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce desired results. Any use of any form of the terms “connect”, “engage”, “couple”, “attach”, or any other term describing an interaction between elements is not meant to limit the interaction to direct interaction between the elements and may also include indirect interaction between the elements described. The various characteristics mentioned above, as well as other features and characteristics described in more detail below, will be readily apparent to those skilled in the art upon reading the following detailed description of the embodiments, and by referring to the accompanying drawings.
Referring to FIGS. 1 and 2 , a loading shoulder 10 is shown installed in a wellhead housing 12 above a previously installed casing hanger 14 and packoff assembly 16 . The loading shoulder 10 includes an energizing ring 18 , a lock ring 20 , a loading ring 22 , and a hold-down ring 24 . The loading shoulder 10 typically includes only metal components. However, the loading shoulder 10 may also include non-metal components that are capable of providing support for a casing hanger. As shown, the lock ring 20 is positioned externally to and in between the energizing ring 18 and the loading ring 22 . Also, the energizing ring 18 , the lock ring 20 , and the loading ring 22 include angled surfaces for sliding engagements at 26 and 28 , respectively. The lock ring 20 is also expandable and may either be a segmented ring, a “C” ring, or any other suitable expandable configuration. Further, the lock ring 20 is shown in a configuration for engaging a corresponding lock ring groove 42 in the wellhead. It should be appreciated, however, that the lock ring 20 and the lock ring groove 42 may be any suitable configuration for proper locking engagement of the loading shoulder 10 . Additionally, the energizing ring 18 and the loading ring 22 overlap in a loading ring threaded connection 30 with the loading ring 22 threaded into the energizing ring 18 .
Opposite the portion threaded into the energizing ring 18 , a catch ring 32 extends from an interior surface of the loading ring 22 into an annular groove 34 on the outside surface of the hold-down ring 24 . Although the catch ring 32 is secured to the loading ring 22 , the size of the groove 34 allows both vertical and rotational movement of the hold-down ring 24 relative to the loading ring 22 . However, the catch ring 32 only allows a certain amount of vertical travel of the hold-down ring 24 relative to the loading ring 22 before the catch ring 32 engages an edge of the groove 34 .
In addition to the catch ring 32 , the loading ring 22 interacts with the hold-down ring 24 through a hold-down ring threaded connection 36 . The direction of the threads of the hold-down ring threaded connection 36 may either be right-handed or left-handed. However, the threads of the hold-down ring threaded connection 36 are an opposite turn than the threads of the loading ring threaded connection 30 . Thus, if the loading ring threaded connection 30 threads are right-hand threads, the hold-down ring threaded connection 36 will include left-hand threads and vice versa.
FIG. 3 illustrates the loading shoulder 10 being run into a wellhead housing 12 for landing on a previously installed casing hanger 14 and packoff assembly 16 . The loading shoulder 10 is run into the wellhead housing 12 using a loading shoulder running tool 38 connected to a drill string or other pipe string. As shown, the landing shoulder 10 is in the unset position and as such may be configured to be run though a blowout preventer stack 40 attached above the wellhead housing 12 . The running tool 38 is used to land the loading shoulder 10 onto a previously installed casing hanger 14 with both the loading ring 22 and the lock ring 20 in the unset position. When landed, the lock ring 20 is aligned with a corresponding lock ring groove 42 in the wellhead housing 12 . Additionally, the lower portion of the hold-down-down ring 24 engages the upper portion of the previously installed casing hanger 14 in a tongue-and-groove arrangement 44 that restrains relative rotation between the hold-down ring 24 and the casing hanger 14 . It should be appreciated, however, that any arrangement suitable for restraining relative rotation may be used.
To set the loading shoulder 10 , the running tool 38 rotates the energizing ring 18 . Because of the tongue-and-groove engagement 44 , both the hold-down ring 24 and the loading ring 22 resist being rotated with the energizing ring 18 . Consequently, the energizing ring 18 rotates relative to the loading ring 22 and the hold-down ring 24 . Because of the loading ring threaded connection 30 , the rotation of the energizing ring 18 relative to the loading ring 22 draws the loading ring 22 further into the energizing ring 18 . Doing so actuates the lock ring angled engagements 26 , 28 to expand the lock ring 20 into engagement with the lock ring groove 42 in the wellhead 12 as shown in FIG. 4 .
Rotation of the energizing ring 18 relative to the loading ring 22 proceeds until either the loading ring threaded connection 30 bottoms out or the lock ring 20 becomes fully expanded into the wellhead lock ring groove 42 . At such time, the loading ring 22 no longer rotates relative to the energizing ring 18 and begins to rotate with the energizing ring 18 . However, the tongue-and groove arrangement 44 still restrains the hold-down ring 24 from rotating, thus producing relative rotation between the loading ring 22 and the hold-down ring 24 with the catch ring 32 rotating within the annular groove 34 .
As previously mentioned, the threads of the hold-down ring threaded connection 36 turn in a different direction than the threads of the loading ring threaded connection 30 . Thus, although the energizing ring 18 rotation direction draws the loading ring 22 further into the energizing ring 18 , the same rotation direction expands the hold-down ring 24 out from the loading ring 22 . Thus, rotation of the loading ring 22 as described expands the hold-down ring 24 out from the loading ring 22 to restrain movement of the casing hanger 14 as well as the packoff assembly 16 below.
As shown in FIG. 5 , once the loading shoulder 10 is set, the running tool 38 may then be disengaged from the loading shoulder 10 and retrieved from the wellhead housing 12 . Further drilling, completion, or other well operations may then proceed.
As shown in FIGS. 6 and 7 , the loading shoulder 10 provides a bi-directional loaded shoulder for the installation of an additional casing hanger 46 that is run into the wellhead 12 and landing on the loading shoulder 10 . When landed, the weight of the casing hanger 46 and the casing string 48 may thus be transferred at least in part to the wellhead housing 12 through the loading shoulder 10 . As shown in FIG. 7 , an additional packoff assembly may also be installed to form a seal between the additional casing hanger 46 and the wellhead 12 .
The loading shoulder 10 may thus provide a positive lock in both the direction extending into the wellbore and the direction extending out of the wellbore to support an additional casing hanger 46 above as well as restrain the casing hanger 14 and packoff assembly 16 below.
While specific embodiments have been shown and described, modifications can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments as described are exemplary only and are not limiting. Many variations and modifications are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims.
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A well production system including a wellhead and a first casing string supported from a first casing hanger landed on a shoulder in the wellhead bore. A loading shoulder assembly is installable in the wellhead and includes an energizing ring, a loading ring threaded into the interior of the energizing ring, a lock ring, and a hold-down ring threaded into the interior of the loading ring. The hold-down ring engages the first casing hanger to prevent rotation of the hold-down ring and restrain rotation of the loading ring. The lock ring is expandable from an unset position into supporting engagement with the wellhead in a set position upon rotation of the energizing ring. The hold-down ring is also moveable axially out of the loading ring to restrain the first casing hanger.
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BACKGROUND OF THE INVENTION
[0001] This invention generally relates to brazing methods, including processes and materials for use in the manufacturing, coating, repair, and build-up of superalloy components. More particularly, this invention relates to a method of brazing a superalloy, in which microwave energy is employed to melt a braze alloy that contains minimal or no melting point depressants relative to the superalloy being brazed.
[0002] Nickel, cobalt, and iron-base superalloys are widely used to form high temperature components of gas turbine engines. While some high-temperature superalloy components can be formed as a single casting, others are preferably or required to be fabricated by other processes. As an example, brazing is widely used to fabricate gas turbine components, as in the case of high pressure turbine nozzle assemblies. Brazing techniques conventionally encompass joining operations performed at an elevated temperature but sufficiently below the melting points of the superalloys being joined so as not to cause grain growth, incipient melting, recrystallization, or unfavorable phase formation that can lead to degradation of the alloys. In carrying out the brazing process, an appropriate braze alloy is placed between the interface (faying) surfaces to be joined, and the faying surfaces and the braze alloy therebetween are heated in a vacuum to melt the braze alloy. The braze alloy melts at a lower temperature than the superalloy base material as a result of containing one or more melting point depressants, such as boron and/or silicon in an amount greater than the superalloy(s) being brazed. For example, whereas superalloys containing intentional amounts (above impurity levels) of boron and/or silicon typically contain less than 0.1 weight percent of each, braze alloys that contain boron and/or silicon as melting point depressants typically contain at least 2.0 weight percent boron, or at least 6.0 weight percent silicon, or both silicon and boron at a ratio of about 3:1. On cooling, the braze alloy solidifies to form a permanent metallurgical bond.
[0003] During engine operation, gas turbine engine components are subject to strenuous high temperature conditions under which various types of damage or deterioration can occur. As examples, erosion and oxidation reduce wall thicknesses of turbine nozzles and vanes, and cracks can initiate at surface irregularities and propagate as a result of stresses that are aggravated by thermal cycling. Because the cost of components formed from superalloys is relatively high, it is often more desirable to repair these components rather than replace them. In response, brazing techniques have been developed for crack repair and wall thickness build-up that entail placing a braze alloy filler metal on the surface area requiring repair, and then heating the filler metal in a vacuum to above its melting point, but below that of the surface substrate, so that the molten filler metal wets, flows, and fills the damaged area.
[0004] While widely employed to fabricate and repair gas turbine engine components, conventional brazing processes have notable disadvantages. For example, the entire component must be subjected to a vacuum heat treatment, which is a very lengthy process in a production environment, unnecessarily exposes undamaged regions of the component to high temperatures, and can potentially remelt joints in other sections of the component. Furthermore, though braze alloys typically have compositions similar to the base metal of the component being brazed, the presence of boron and/or silicon in a braze alloy as a melting point suppressant reduces the mechanical and environmental properties of the resulting brazement as a result of the minimal ductility of the borides and silicides they form by reaction with refractory elements. Boron and silicon can also diffuse into the base metal repaired by the brazement to adversely affect the mechanical and environmental properties of the component.
[0005] Microwave brazing has been investigated as a potential candidate for eliminating these issues, as heating can be localized to selected areas of a component. The general approach has been to use a susceptor (e.g., SiC enclosure) that is heated when exposed to microwave energy and, in turn, transfers the heat to the component by radiation. Drawbacks include the lack of local heating of the braze alloy only, as an entire region of the component is inevitably heated, and significant heat loss from radiation in directions away from the intended brazement.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention generally provides a process for heating a braze alloy by microwave radiation so that heating of the alloy is selective and sufficient to cause complete melting of the alloy and permit metallurgical bonding to a substrate on which the alloy is melted, but without excessively heating the substrate so as not to degrade the properties of the substrate. The invention is particularly beneficial for use in brazing operations for the purpose of metallurgically joining superalloys and coating, repairing, and building up of superalloy surfaces.
[0007] The process generally entails providing metallic powder particles having essentially the same metallic composition, with at least some of the metallic powder particles being sufficiently small to be highly susceptible to microwave radiation. A mass of the metallic powder particles is then applied to a surface of a substrate, after which the mass is subjected to microwave radiation so that the metallic powder particles within the mass couple with the microwave radiation and sufficiently melt to metallurgically bond to the substrate. The microwave radiation is then interrupted and the mass is allowed to cool, solidify, and form a solid brazement.
[0008] According to a preferred aspect of the invention, the metallic powder particles may have the same metallic composition as the substrate on which the mass of particles was applied and melted. According to another aspect of the invention, all of the metallic powder particles are sufficiently small to be significantly more susceptible to absorbing microwave energy than the substrate, which predominantly reflects the microwaves. As a result, complete melting of the particles can be achieved accompanied by only surface melting of the substrate caused by heat transfer from the particles to the substrate by thermal conduction. Such a result may be obtained even if the metallic powder particles have the same or even higher melting temperature than the substrate. Finally, melting of the particles can be achieved even if their metallic composition is free of melting point depressants, such as boron and silicon, beyond amounts conventionally used in superalloys.
[0009] From the above, it can be appreciated that the process of this invention can be applied to various processes in which heating of a powdered material is desired, for example, the forming of coatings including the repair or build-up of a damaged surface and the metallurgical joining of components by brazing. Because heating is by microwave radiation, the heating rate and melting of the powder particles are influenced by susceptibility to microwave radiation instead of location relative to a heating source or relative to any surface contacted by the powder mass. This aspect of the invention enables the powder mass to melt prior to melting of the surface contacted by the mass. As a result, the powder particles can be formed of an alloy having the same melting temperature (for example, within 150° C.) as the surface contacted by the powder mass.
[0010] Other objects and advantages of this invention will be better appreciated from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 schematically represents a mass of powder metal particles between a pair of substrates, in which the powder metal particles are susceptible to microwave heating to enable microwave brazing in accordance with an embodiment of the present invention.
[0012] FIG. 2 schematically represents a mass of powder metal particles similar to that of FIG. 1 but deposited on a surface of a substrate containing a defect in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The invention will be described with specific reference to processing of components for a gas turbine engine, and particularly the fabrication and repair of such components with a braze material. However, the invention has application to a variety of components, materials, and processes other than those discussed, and such variations are within the scope of this invention.
[0014] FIGS. 1 and 2 depict embodiments of this invention, in which consistent reference numbers are used to identify functionally similar structures. FIG. 1 schematically represents a mass 10 of powder metal particles 12 between and contacting opposing surfaces of two substrates 14 and 24 to be metallurgical joined by the particles 12 , and FIG. 2 schematically represents a mass 10 of powder metal particles 12 deposited on a surface of a substrate 14 for the purpose of repairing a defect in the surface. As discussed below, the invention provides a process by which the particles 12 are melted and resolidified to form brazements that join the substrates 14 and 24 of FIG. 1 and repair the surface defect of FIG. 2 . Though the mass 10 of particles 12 is shown as being directly placed between the substrates 14 and 24 in FIG. 1 , and the mass 10 of particles 12 is shown as placed directly within the defect in FIG. 2 , it will be understood by those skilled in the art that the particles 12 could be placed adjacent a gap between the substrates 14 and 24 in FIG. 1 or over the defect in FIG. 2 , and allowed to flow into the gap and defect by capillary action when molten. In both FIGS. 1 and 2 , the particles 12 are shown as being contained within a binder 30 that, according to known brazing practices with braze pastes, burns off during the brazing process, which is preferably performed in an inert or low pressure atmosphere to minimize oxidation of the particles 12 and any surfaces (e.g., substrates 14 and 24 ) to which the particles 12 are bonded. Either or both substrates 14 and 24 may be formed of a superalloy, whose composition or compositions will depend on the particular type of component and its anticipated operating conditions. As will be noted below, various other metallic materials are also possible for the substrates 14 and 24 , and therefore within the scope of the invention.
[0015] According to the invention, the mass 10 of particles is melted as a result of being subjected to microwave radiation 26 , as discussed in more detail below. The powder particles 12 can be formed of a variety of materials, limited only by the requirement that the particles 12 have a composition that is capable of being heated by microwave radiation 26 and is compatible with the materials of the substrates 14 and 24 while at the maximum heating temperature induced by microwave radiation 26 . Materials capable of being heated when subjected to microwave radiation include non-conductors and conductors under appropriate conditions. Microwave radiation has varying electric and magnetic fields that are believed to cause direct electric heating and heating through magnetic effects, respectively. For compatibility with the metallic substrates 14 and 24 , the particles 12 employed by this invention are metallic and are believed to be heated by a combination of electrical and magnetic effects, with the latter possibly being the dominant effect. Compatibility is assured if the particles 12 have the very same composition as that of the substrates 14 and 24 , though suitable compatibility can also be achieved if the particles 12 and substrates 14 and 24 do not have compositions prone to detrimental interdiffusion at elevated temperatures that would lead to loss of desired mechanical or environmental properties. The particles 12 may be a conventional braze alloy that contains significant amounts of one or more melting point depressants, such as up to two weight percent boron or up to six weight percent silicon, or some combination of both. Conversely, the particles 12 may contain elements capable of serving as a melting point depressant at only impurity levels or in only limited amounts that do not exceed the levels for those same elements in the substrate 14 or substrates 14 and 24 being brazed, for example, less than 0.1 weight percent for both boron and silicon in typical nickel-base superalloys. Another alternative is to form the particles 12 to have a composition that contains lower amounts of boron and/or silicon than typically added as a melting point depressant, for example, less than one weight percent of boron and/or less than three weight percent of silicon. As such, it is possible for the particles 12 to contain one or more melting point suppressants, though not at levels that would lead to an unacceptable loss of properties in the substrates 14 and 24 as a result of diffusion of the suppressant into the substrates 14 and 24 during heating of the particles 12 and later during the life of the substrates 14 and 24 . Furthermore, the particles 12 can be formed of a superalloy such as of the type used in turbine applications, or an alloy whose base composition is similar to that of the substrates 14 and 24 but modified to contain alloying constituents different from or at different levels than the substrates 14 and 24 . Though all of the particles 12 are not required to have the same composition, the present invention permits such uniformity.
[0016] According to a preferred aspect of the invention, at least some and preferably all of the powder particles 12 must be sufficiently small to be highly susceptible to microwave radiation 26 , thereby preferentially coupling with the microwave radiation 26 (as compared to the substrates 14 and 24 ) to significantly enhance heating and melting of the particles 12 by the microwave radiation 26 . Coupling with the microwave radiation 26 is believed to be the result of the metallic particles 12 being sufficiently conductive to generate eddy currents induced by the magnetic field of the microwave radiation 26 , while possibly also possessing a level of electrical resistivity capable of generating joule heating from the eddy currents. It is known that the magnetic loss component of susceptibility for a material in very fine powder size is dependent on factors such as microwave power and frequency. Conversely, for a given microwave power and frequency, the interaction between microwave and individual metals or alloys will be optimum at a distinct particle size, usually on the order of a few tens of nanometers for conventional microwave conditions (about 2.45 GHz and about 1 to about 10 kW power). Particle sizes above or below that size will not couple as well with the microwave radiation. Consequently, suitable and preferred maximum sizes for the particles 12 will depend on the particular application, temperatures, and materials involved. Generally speaking, it is believed that a maximum particle size is on the order of about 150 mesh (about 100 micrometers), more preferably less than 325 mesh (about 44 micrometers). Minimum particle sizes can be as little as nanoscale, e.g., less than 100 nanometers such as on the order of about 10 nanometers.
[0017] In contrast to the particles 12 , bulk metals such as the substrates 14 and 24 tend to reflect microwave radiation. As noted above, this aspect of the present invention makes possible the brazing of superalloy substrates 14 and/or 24 with alloys having the very same composition as the substrate 14 / 24 , as well as alloys with the same or even higher melting point as the substrate 14 / 24 . For example, a nickel-base superalloy component can be joined or repaired with a braze material of the same nickel-base superalloy composition or another nickel-base alloy, in other words, an alloy whose base metal is the same as the base metal of the substrate 14 / 24 . In this manner, degradation of the properties of the substrate 14 / 24 resulting from interdiffusion with the braze material can be essentially if not entirely avoided. In view of the capability of melting particles 12 formed of an alloy having a melting point above that of the substrate 14 / 24 , it should be appreciated that the term “brazing” as used herein is not limited to the conventional limitation of a joining operation performed at a temperature below the melting point of the metals being joined.
[0018] Microwave radiation is preferably applied to the powder mass 10 in a multi-mode cavity, which as known in the art provides for a microwave field that does not establish a standing wave, but instead provides a uniform amplitude of both its magnetic and electric components. Alternatively, a single-mode cavity can be used, in which case a standing or traveling wave is propagated, enabling imposition, to a certain extent, the relative amplitudes of the electric and magnetic components of the microwave field. A wide range of microwave frequencies could be used with the present invention, though regulations generally encourage or limit implementation of the invention to typically available frequencies, e.g., 2.45 GHz and 915 MHz, with the former believed to be preferred. However, it should be understood that other frequencies are technically capable of use. A benefit of using a lower frequency is the greater associated wavelength, which may be better suited for higher power transmission or processing of larger components. Suitable microwave power levels will depend on the size and composition of the particles 12 , but are generally believed to be in a range of about 1 to about 10 kW, though lesser and greater power levels are also foreseeable.
[0019] In an experiment using a multi-mode microwave cavity, about 5 grams of a nanoscale-sized nickel powder and about 25 g of a nickel powder sieved to −325 mesh were subjected to microwave radiation at frequencies of about 2.45 GHz and power levels of about 1 kW. A maximum temperature of about 1140° C. (about 2085° F.) was obtained for the finer nickel powder, while the coarser nickel powder only attained a temperature of about 817° C. (about 1500° F.), evidencing the greater susceptibility of the finer powder particles to heating by microwave radiation.
[0020] While the invention has been described in terms of particular embodiments, it is apparent that other forms could be adopted by one skilled in the art. Accordingly, the scope of the invention is to be limited only by the following claims.
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A process for heating a braze alloy by microwave radiation so that heating of the alloy is selective and sufficient to cause complete melting of the alloy and permit metallurgical bonding to a substrate on which the alloy is melted, but without excessively heating the substrate so as not to degrade the properties of the substrate. The process entails providing metallic powder particles having essentially the same metallic composition, with at least some of the particles being sufficiently small to be highly susceptible to microwave radiation. A mass of the particles is then applied to a surface of a substrate, after which the mass is subjected to microwave radiation so that the particles within the mass couple with the microwave radiation and sufficiently melt to metallurgically bond to the substrate. The microwave radiation is then interrupted and the mass is allowed to cool, solidify, and form a solid brazement.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to apparatuses for controlling the exchange of air through doorways or other openings to refrigerated spaces, and more particularly to an improved conditioned air vestibule for use at a doorway of a refrigerated or cold storage room.
2. Description of the Prior Art
Doors provide access to cold storage rooms from anterooms or loading docks or other adjacent spaces for material handling vehicles and pedestrian traffic. Traffic through the doors is frequently heavy particularly at peak periods of the day so that the doorways are necessarily open at least a substantial portion of the time and many are kept open continuously during such peak traffic periods. Such open doorways present problems both with regard to operation and maintenance of refrigeration equipment and with regard to the productivity and safety of the facility.
As is recognized, an open doorway to a refrigerated space permits the heavier refrigerated air to flow out of the refrigerated space through the lower half of the opening and an equal mass of warm humid air to flow inward through the upper half. In this air exchange, warm air entering the refrigerated space is referred to in the industry as infiltration air, and cold air escaping is sometimes referred to as exfiltration air.
When a warm air mass encounters a cold air mass, precipitation commonly occurs, the eventuality of this phenomenon depending upon conditions of the two air masses relative to one another. The form of precipitation, i.e., water droplets or airborne ice crystals, depends upon the temperature of the mixture.
The warm and cold side conditions at the entrance to subfreezing cold storage rooms or freezer rooms are generally in the precipitation range relative to each other, at least during mild and warmer weather, and almost always in the warmer climates. As warm air enters through the top of a freezer room door, precipitation in the form of airborne ice crystals is visible as haze while visible fog frequently appears outside the door as cold air escapes from the bottom of the door and mixes with the warm humid outside air. Warm side fog can obstruct the vision of personnel, including vehicle operators, working in the area. In addition, the chilled fog-laden air frequently causes wet slippery floors in the vicinity of the doorway with consequent hazards not only to personnel but also to equipment and material.
Precipitation from infiltration air is generally found to be even more objectionable than fog outside the door. The airborne ice crystals result in frost or snow accumulation on ceilings, walls, and freezer room appurtenances as well as on products stored in the room. Such frost frequently grows to many inches in thickness and can result in snow droppings which cause icy floors and present extremely slippery and hazardous conditions for forklift trucks. Further, the airborne ice crystals may be drawn into the refrigeration equipment and produce premature clogging of the coils, as compared with normal evaporator coil icing, thereby reducing the refrigeration effect and adding coil defrosting burden. The result is a substantial reduction in refrigeration efficiency and may require installation of additional evaporator coils or oversized refrigeration equipment.
Many attempts have been made to reduce the air exchange at open refrigerated warehouse doors. One approach has been to employ an air curtain across the door, with the forced flow of relatively high velocity air across the opening serving to restrict the normal air exchange resulting from the temperature differential. It is also known to condition air used in such air doors by heating the air employed in the air curtain to reduce precipitation both inside and outside the refrigerated space. Examples of such devices may be found, for example, in U.S. Pat. Nos. 3,218,952, 3,817,160, 4,516,482 and U.S. Pat. No. Des. 264,561.
A relatively short conditioned air vestibule having two spaced air curtain doors employing conditioned air in the air curtain is illustrated in U.S. Pat. No. Des. 140,200. Such devices, while effective in reducing precipitation both inside and outside a refrigerated warehouse door, they don't eliminate such precipitation.
Physical barriers, particularly the well-known strip doors, are also widely used to restrict the flow of air through an open refrigerated warehouse door. Such strip doors employ transparent vinyl strips which enable personnel and vehicles to push through, with the strips quickly falling back into place to act as an air flow barrier when the obstruction has cleared the door.
Another known system for controlling precipitation from infiltration or exfiltration air employs a step-down room at the door, with the step-down room having a physical barrier such as a strip door or rigid push-through door at each end for restricting air exchange. The air inside such step-down rooms is heated to a non-fogging or non-frost producing level and to prevent airborne crystal formation in the refrigerated room as a result of air infiltration. This level of heat is normally found sufficient to prevent fog formation as a result of air exfiltration from the step-down room. The known step-down rooms are of sufficient size to permit material handling vehicles to enter one end and the door to close behind it before reaching and pushing through the door at the other end. Such arrangements are therefore costly both because they occupy substantial floor space and because of the relatively large volume of heated air required.
Large step-down rooms also have generally been considered objectionable in that their tunnel configuration tends to restrict the vision of forklift operators and therefore can present a safety hazard. For this reason, it has been common practice to provide two step-down rooms to enable one way traffic entering and leaving the cold storage room.
The use of push through strip doors is also objectionable in that the strips tend to become less transparent with use and may present an obstruction to vision. Further, frost or fog condensation on the strip surfaces not only obstruct vision, but the wet, cold surfaces are generally considered objectionable by personnel passing through the door. The relatively heavy plastic strips can also drag lightweight items such as empty cartons from material handling equipment.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide an efficient, effective and energy conserving conditioned air vestibule which is operable to control air exchange through a cold storage room door and which overcomes many of the defects of the prior art apparatus.
Another object is to provide such a conditioned air vestibule which may be installed on either the warm side or the cold side of existing cold storage room doors and which is operable to greatly reduce the flow of infiltration air into and exfiltration air out of cold rooms.
Another object is to provide such a conditioned air vestibule which occupies a minimum of floor space and which may safely be used for two way traffic through the cold storage room door.
Another object is to provide such a conditioned air vestibule including means for conditioning air within the vestibule so that any airflow through the vestibule will not result in precipitation.
Another object is to provide such a conditioned air vestibule which is effective in maintaining all see-through and other surfaces of the vestibule clear of frost and moisture.
Another object is to provide such a conditioned air vestibule which is economical to operate and which requires a minimum of maintenance.
The foregoing and other objects and advantages of the invention are achieved in a first preferred embodiment wherein multiple air-curtain apparatuses for controlling and conditioning the flow of air through an opening in a vertical wall of a cold storage room comprises at least three air curtain units arranged in aligned, spaced-apart and substantially parallel relationship to form a vestibule positioned adjacent to and in register with said opening. Each of said units comprises (1) first and second vertically oriented air manifold members respectively positioned adjacent the sides of said opening and extending from the bottom to the top of said opening, said first manifold member being an air discharge means including longitudinally-disposed, laterally-positionable directional blades arranged from top to the bottom thereof, and said second manifold member being an air return means and having air inlet means disposed from the top to the bottom thereof, and (2) air transport means including air blower means connected to said first manifold member and adapted to supply pressurized air thereto, and further including air return means connecting said second manifold member to inlet means of said blower means. The air curtain units are arranged so that their respective first manifold members are proximate or adjacent to the second manifold members of the next adjacent air curtain units and the blades of said first manifold members are preselectively sized and set or directed as follows:
i) said blades at the top of said first manifold members are sized and are set at a preselected maximum discharged air momentum countering relatively warm and moist air flow through said opening into said room;
ii) said blades at the bottom of said first manifold members are sized and are set at a preselected maximum orientation toward said cold storage room to provide maximum discharged air momentum countering relatively heavy cold air from said room through said opening; and
iii) said blades, on a preselected graduated basis, are sized and set so that the blades, at a preselected intermediate position, have (1) an orientation parallel to said opening and toward said second manifold members; and (2) a reduced preselected discharged air momentum.
The above-described first embodiment provides significant improvements in performance over all known prior art arrangements.
A second preferred embodiment of the invention yields even greater economy of operation by adding a heating function to one of the air curtain units. This aspect of the invention is relevant to vestibules comprising three or more air curtains.
A third preferred embodiment yields even greater economy of operation; this embodiment combines at least two air curtains in a vestibule with one of the air curtains discharging heated air and another of the air curtains discharges cooled air.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the invention will be apparent from the detailed description contained hereinbelow, taken in conjunction with the drawings, in which:
FIG. 1 is an isometric drawing of a prior art double-curtain conditioned air vestibule;
FIG. 2 is an isometric showing of a prior art discharge air assembly which may be used with the apparatus shown in FIG. 1;
FIG. 2a is an enlarged view of the air straightener used in FIG. 2;
FIG. 3 is a front elevation view, on a smaller scale, of the device shown in FIG. 2;
FIGS. 3, view A--A, view B--B, and view C--C are views of FIG. 3 as viewed along section lines A--A, B--B and C--C;
FIG. 4 is a diagram showing a cross-section of a structure including a freezer or cold storage room and an outer room, or anteroom, or loading dock, with a doorway provided in a wall of the freezer leading to the outer or anteroom, FIG. 4a is a psychrometric chart of standard form with dry-bulb air temperature and air humidity ratio on the X and Y axes respectively, and with a saturation line depicted;
FIG. 5 is a schematic showing a prior art double-air curtain with heat;
FIG. 6 depicts schematically one embodiment of my invention, comprising three or more air curtains arranged in a vestibule;
FIGS. 7, 8 and 9 are schematics depicting another embodiment of my invention comprising three or more air curtains arranged in vestibules with at least one of the vestibules having auxiliary heat means for heating the air supplied to the supply duct or manifold of the air curtain;
FIGS. 10, 11, 12 and 13 depict schematically another embodiment of my invention comprising two or more air curtains with heat being supplied to the supply manifold of one of the air curtains and with another of the air curtains having auxiliary air cooling means for supplying cooled air to the supply manifold thereof;
FIG. 14 is a schematic diagram of a vestibule comprising four separate spaced-apart air curtains, A, B, C and D showing one possible orientation of the vestibule with respect to the opening in the wall between the anteroom and freezer, and also showing how the supply (M S ) and return (M R ) ducts or manifolds are alternated in the vestibule;
FIG. 15 is a schematic showing a double curtain air unit with heavy arrows showing primary airflow and lighter arrows showing secondary airflow;
FIG. 16 shows three possible orientations of the vestibule with respect to the opening in the wall between the anteroom and freezer;
FIG. 16a shows the vestibule within the freezer room and abutting the opening;
FIG. 16b shows the vestibule positioned in the opening and having portions in both the anteroom as well as the freezer;
FIG. 16c shows the vestibule positioned in the anteroom in register with and abutting the wall opening;
FIG. 17 is an isometric schematic of a dual air-curtain apparatus with heating and cooling, and with the control means for controlling the heating and the cooling of the air being supplied to the supply duct of the two air curtains respectively; and
FIG. 18 is an isometric showing of a prior art intake-air assembly which may be used with the air curtain units shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a prior art showing of a pair of air curtains configured as a vestibule, i.e., air curtain unit M and air curtain unit BB, each comprising first and second vertically oriented air manifold members, i.e., air discharge ducts or supply manifolds M S and air return ducts or manifolds M E . The units AA and BB are shown spaced apart with sidewall means SW positioned therebetween to prevent lateral air from entering the vestibule. Each of the air curtain units has associated therewith a fan or blower means F positioned on top of the structure, adapted to receive air from the return ducts or manifolds M R and to supply air under pressure to the supply manifolds M S .
FIG. 2 shows a prior art discharge air assembly or manifold M S ; the assembly is an elongated rectangular duct or plenum having a top opening 20 receiving pressurized air 21 from a motor driven blower or fan F (see FIG. 1). A constant velocity baffle 22 positioned within the plenum extends from the upper left hand corner diagonally downward at an angle to a bottom intermediate position as shown. The discharge air assembly further includes a housing 26 for a plurality of air straighteners 28, the air straighteners being shown in greater detail in FIG. 2A. The air straighteners 28 comprise a slanted upwardly portion 28A adapted to be impacted by the air 21 moving vertically down as shown in FIG. 2 and a air straightener horizontal portion 28B; the function of the air straighteners is to systematically, and with minimum air turbulence, capture the vertically moving air 21 and have it discharged out of assembly M S on a horizontal basis as is depicted in FIG. 2A. A pair of directional blades 29 and 30 extend longitudinally from the top to the bottom of the housing 26, and are preset at a preselected orientation by suitable means such as brackets (not shown) to achieve the orientation shown in FIG. 3AA, FIG. 3BB and FIG. 3CC. More specifically, it will be noted that, as viewed in FIG. 2, the tops of the blades 29 and 30 are angled to the left side of unit M S ., while the bottom ends of 29 and 30 are angled to the right. It should further be noted that the blades 29 and 30 are spaced apart at the top and at the bottom a greater amount than the spacing at the midpoint or preselected intermediate point; the purpose of this is to provide a variation in the momentum of the air flowing through the blades. This is depicted in FIG. 2 by schematic air vectors 35-40. The width of the shaft of the arrows is intended to be indicative of the magnitude of the momentum of the air. Thus, for example, air vectors 35 and 40 at the top and bottom, respectively, of the assembly, have the largest air momentum; vectors 36 and 39 are of intermediate values of momentum; and vectors 37 and 38, which are closest of the middle or center of the assembly, are of the smallest air momentum.
FIG. 18 shows a prior art return or intake air assembly, or manifold M R ; the assembly is an elongated rectangular duct or plenum having a top opening 11 adapted to being connected to the intake of fan F (see FIG. 1); the total air return is represented by the vector 12.
Manifold M R has an inward-facing side 13 with top and bottom characterized air intake apertures 14 and 15; the characterization being preselected to cause the air flow into M R to substantially match the airflow from the discharge or supply manifold M S , it being understood that the airflow from MS is horizontally, or laterally across the vestibule to M R . Thus, in FIG. 18 the intake momentum vectors are identified by reference numerals 2, 3 and 4 (on the top) and 5, 6 and 7) on the bottom; vectors 2 and 7 on the top and bottom, respectively, are the largest; vectors 4 and 5 closest to the middle are the smallest; and intermediate vectors 3 and 6 represent air momentum of intermediate values.
FIG. 4 is helpful for understanding the physics associated with the aforementioned problems associated with a doorway or other opening in a wall of a refrigerated warehouse. A freezer room 42 has an associated outer or anteroom 43 with a wall 44 positioned between the two rooms. A wall opening such as a doorway 45 may be adapted to be closed off selectively by a conventional door 46. Whenever the door is open (a frequent occurrence for a busy warehouse) relatively warm, humid and light air 50 infiltrates from the anteroom 43 into the freezer room 42 through the top portion opening 45 while simultaneously relatively heavy, cold air 51 is exfiltrated from the freezer room into the anteroom through the lower half of the opening. This problem is well understood and the consequences of the infiltration and the exfiltration are very significant. As indicated above, the light, moist air infiltrated into the freezer room forms airborne ice crystals which can fall onto the floor to create dangerous icy and slippery floors; the ice crystals also can cause ice to be formed on the walls and the goods which are being stored in the warehouse; thus a hazardous working environment as well as damage to the goods can be created.
Concurrently, the heavy, cold air exfiltrated from the freezer room through the open doorway or opening can create a substantial amount of fog in the anteroom zone which creates an additional hazard for personnel. Also, the floor in the anteroom may become wet and slippery; another hazard.
FIG. 4A shows a psychrometric chart which will be understood by those skilled in the art to correlate the above-described actions of FIG. 4 with respect to the formation of the airborne ice crystals in the freezer room 42.
FIG. 5 is a schematic of a prior art double-air-curtain apparatus, i.e., air curtains 60 and 61 arranged to form a vestibule associated with an opening in a wall of a freezer room (not shown). Air curtain 60 has supply and return manifolds S and R on the right and left respectively as shown. The nomenclature R and S being used both for this figure as well as for FIGS. 6-13 to designate, respectively, return air manifolds and supply manifolds. It will be further noted that the air curtain 61 has manifolds which are the reverse of air curtain 60, i.e., the return manifold is on the right and the supply manifold is on the left as depicted. The prior art arrangement shown in FIG. 5 had a certain level of effectiveness for reducing the aforesaid problems of icing, fog, and energy consumption, but has not proven fully satisfactory from the standpoint of operating cost.
FIG. 6 depicts a first embodiment of my invention, namely a multiple air curtain apparatus for controlling and conditioning the flow of air through an opening in a vertical wall of a cold storage room and comprising at least three air curtain units arranged in aligned, spaced-apart and substantially parallel relationship to form a vestibule positioned adjacent to and in register with the wall opening. In FIG. 6, three air curtains 63, 64 and 65 are arranged in aligned, spaced-apart and substantially parallel relationship to form a vestibule positioned adjacent to and in register with the opening (not shown). It will be noted from FIG. 6 that the return and supply manifolds are alternated. Thus the return manifold of air curtain 63 is proximate or adjacent to the supply manifold at the left end of air curtain 64. Further, the return manifold for air curtain 65 is at the left end thereof as shown, and so forth. Significant economic advantage is derived from using the invention depicted in FIG. 6; this configuration of three or more air curtains has been found to significantly reduce the amount of warm moist air infiltrating into the freezer room and to simultaneously reduce the amount of cold air exfiltrating from the freezer room and to lower the operating cost.
A second embodiment of my invention is depicted in FIGS. 7, 8 and 9 wherein a plurality of at least three air curtain units are arranged in aligned, spaced-apart and substantially parallel relationship to form a vestibule positioned adjacent to and in register with the wall opening (not shown). The difference between this embodiment and the embodiment shown in FIG. 6 is that a heat stage is provided for one (or more) of the air curtain units. Thus, in FIG. 7 three air curtain units 67, 68 and 69 are provided, with the heating means being associated with air curtain 69 most proximate to the freezer room. The heating means is identified by reference numeral 70 for the apparatus depicted schematically in FIG. 7.
FIG. 8 depicts four air curtains, 71, 72, 73 and 74 arranged in a vestibule with air curtain 74 having heating means 75 associated therewith proximate to the freezer room. An optional arrangement from that shown in FIG. 8 is depicted in FIG. 9 wherein four air curtains 76, 77, 78 and 79 are arranged in a vestibule and with heating means 80 being associated with air curtain 78.
A third embodiment of my invention is depicted in the schematic representation shown in FIGS. 10, 11, 12 and 13; these configurations can be characterized as at least two air curtain units arranged in aligned, spaced-apart and substantially parallel relationship to form a vestibule positioned adjacent to and in register with a wall opening, and further characterized by one of the air curtains associated therewith having heating means for heating the air which is discharged from the air discharge means of the supply manifold, and further comprising cooling means associated with another of the air curtains in the vestibule for cooling the air being discharged from the air discharge means of the air supply manifold. The aforementioned heating and cooling functions are preselected with respect to the locations of the anteroom and the freezer room so as to significantly reduce the amount of water vapor infiltrated into the freezer room.
FIG. 10 depicts a pair of air curtains 82 and 83 having respectively cooling and heating means 84 and 85.
FIG. 11 shows three air curtains 87, 88 and 89 arranged to form a vestibule, and air curtains 87 and 88 have respectively associated therewith cooling means 90 and heating means 91.
FIG. 12 shows four air curtains 93, 94, 95, and 96 arranged to form a vestibule and air curtains 93 and 95 have associated therewith respectively cooling means 97 and heating means 98.
FIG. 13 depicts four air curtains 100, 101, 102 and 103 arranged to form a vestibule and air curtains 101 and 102 have respectively cooling means 104 and heating means 105.
It will be noted in the systems depicted in FIGS. 10, 11 and 12 that the cooling means is associated with the air curtain most proximate to the anteroom; the function of the cooling of the air being discharged by the supply manifold is to remove moisture from the air infiltrating into the freezer room. Thus, it is usually most efficient to have the "cooling" air curtain closest to the anteroom. The arrangement shown in FIG. 13 is a modification of this principal wherein the cooling function is in the second air curtain spaced away from the anteroom. It will be noted, however, that for all variations of this embodiment of the invention, as exemplified by FIGS. 10-13, the air curtain which includes the heating function is always positioned between the wall opening and the air curtain having the cooling function. Stated otherwise, the progression is from the anteroom, the cooling function, the heating function and, finally, the freezer room.
FIG. 14 depicts a plurality of air curtains A, B, C and D arranged in aligned, spaced-apart and substantially parallel relationship to form a vestibule positioned adjacent to and in register with the depicted wall opening in a wall positioned between a freezer room and an anteroom. It will be understood that some means such as a sidewall SW depicted in FIG. 1 would be provided between the air curtains to prevent air from the sides of the vestibule infiltrating into the inner passageway of the vestibule. It should also be understood that the schematic arrangement shown in FIG. 14 is applicable to the arrangements depicted in FIGS. 5-13.
FIG. 16 shows schematic variations of the relationship of the vestibule with respect to the wall between the freezer and the anteroom. In FIG. 16A, the vestibule (which should be understood to comprise at least two air curtain units) is positioned substantially within the freezer room and with the air curtain units being arranged in aligned, spaced-apart and substantially parallel relationship, and in register with the opening in the wall. The arrangement shown in FIG. 16B has the vestibule positioned so as to straddle the wall opening and the arrangement in FIG. 16C has the vestibule positioned substantially in the anteroom but adjacent to the opening.
In FIG. 15, a double air curtain is shown in plan view, with the heavy arrows showing primary airflow from the supply manifolds to the return manifolds and the lighter arrows show a secondary airflow which, as depicted, is shown to have a clockwise vortex-like action or flow.
FIG. 17 is an isometric depiction of a double air curtain embodiment of the invention having both the heating and cooling function, the air curtains being identified by references A and B. Air curtain A is positioned most adjacent to the freezer side of the vestibule and comprises the elements labeled in the figure which include a return duct and supply duct connected, as described above, with a motor driven fan. It should be specifically noted that a heating coil or heating means is inserted in the ductwork connecting the fan to the supply duct.
Likewise, the air curtain B has a supply duct and a return duct, and a motor driven fan, a cooling coil being provided to cool the pressurized air being transferred from the fan to the supply duct. FIG. 17 may be considered to be a depiction of the cooling coil and the heating coil being associated with a heat pump.
While a preferred embodiment of the invention has been illustrated, it will be understood that variations may be made by those skilled in the art without departing from the inventive concept. Accordingly, the invention is to be limited only by the scope of the following claims.
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An improved, low-cost conditioned air vestibule for use on a doorway of a refrigerated storage room permits unobstructed passage of vehicles while effectively reducing the exchange of air through the doorway and substantially eliminating precipitation both inside and outside the doorway.
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This application is a continuation, of application Ser. No. 676,328, filed Nov. 29, 1984, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a throttling control choke valve. More particularly, this disclosure pertains to a wider operating range choke valve and reduced valve seat and stem seat erosion. The disclosure also pertains to valve body erosion and corrosion resistance and detection.
Variable choke valves or fluid flow regulation valves are used in flow lines leading from oil and/or gas producing wells and sometimes in flow lines leading to water injection wells. These flow line chokes have movable means for varying the amount of restriction to be imposed by the choke on the fluids flowing through the flow line. Three types of movable means are in general use. One type valve uses dual parallel discs with a circular aperature in each disc. The maximum flow rate is dependent on the size of the hole and throttling action is obtained by varying the amount of alignment of the holes. A second type of choke valve uses a cylindrical perforated cage in combination with a cylindrical piston or a cylindrical sleeve. Either the piston or sleeve or the cage is movable to vary the size and number of perforations through which the fluids may flow from the inlet to outlet side of the valve. The third type of valve employs a valve stem with a tapered end which is moved in and out of a similarly tapered member in the valve to vary the amount of opening through which the fluids may flow. This type of choke valve is commonly referred to as a needle and seat valve. Without a change of inner members, these common choke valves have limited effective flow rate range abilities, generally operating between 30% and 80% of full capacity. Ideally a choke control valve should be able to control the flow of liquids and gases, including entrained particles, over a range from a few percent to 90% at variable pressure differentials without the need for changing inner valve choke members. For example, some oil and gas producing operations occur in very cold areas where it is important to maintain sufficient liquid flow, for example, about 5%, to prevent freezing or congealing of the liquid in the line.
The requirements for choke valves are among the most severe, for any valve service choke control valves are subject to greatly aggrevated erosion and/or corrosion of the inner surface of the valve body and the inner valve members in the valve just before, at, and just downstream of the point of throttling. The aggrevated erosion and corrosion is a combination of several conditions. Petroleum fluids frequently contain sand-like mineral particles, brine and acid gases. The erosive and corrosive characteristics of petroleum fluids in throttle valves is aggrevated by the effects of increased fluid turbulence, impingement on metal surfaces and fluid cavitational phenomena. Ideally the valves should have long life and should be easy to maintain. Choke valve designers have tried without total success to eliminate erosion and corrosion. It has become common practice to use erosion and corrosion resistant pistons, sleeves, cages, tapered stem tips, and valve seats made of or plated or lined with tungsten carbide, chrome stainless, stellite and ceramics. It has also become common practice to line the valve body inlet, chamber and outlet with such erosion and corrosion resistant materials. Despite these preventive measures, valve seats and members still continue to erode altering the control characteristics and abilities of the valve and frequently rendering the valve unreliable. In addition, valve bodies still continue to fail. Failures are dangerous, environmentally undesirable and clean ups and repairs costly. Routine X-ray, ultrasound and other procedures for detecting body erosion, pitting or other forms of metal loss are rendered unrealible by the such carbide and other preventive materials. Ideally the choke valve should be designed in a way that minimizes erosion of the critical valve shut off points and of surfaces on the movable part of the valve and on mating seat surfaces. Moreover, ideally metal loss adjacent the inner surfaces of the valve should be detectable before substantial erosion and corrosion of the valve body occurs.
Accordingly, it is the primary object of this invention to provide a variable choke control and shutoff valve leaving the aforementioned ideal charcteristics.
SUMMARY OF THE INVENTION
There are provided several embodiments of a throttle choke control valve for petroleum production and injection wells. In all embodiments the valve has inlet, chamber and outlet sections with valves set and throttle means movably disposed to be moved into and out of the valve set and control flow through the valve. In several variations, the more erosive outlet sections or the other sections or the entire valve body are lined with erosion and corrosion liners in a manner such that if the liners erode or corrode through fluid will pass to one or more monitoring passages and to one or more detection points in the valve body and the maintenance friendly liner or liners may be replaced.
Further embodiments concern a throttle means operable over a wide range of flow rates from a few percent to almost total flow. The throttle means is a special nose piece with at least one throttling flow passage communicating with longitudinal flow passage in the outlet part of the nose piece. More preferably, there are at least two longitudinally spaced apart throttling passages of different size communicating with the longitudinal outlet flow passage in the outlet of the nose piece. The throttling passages act like fixed orifices for the low range of flow rates. These throttling passages also reduce erosion by causing a significant portion of the fluid to impinge upon fluid and lessen erosion of the upper part of the valve seat. Another variation pertains to a tapering positive shut off section of the nose piece upstream of throttling passages inside the nose piece. Unlike prior valves, the positive shut off section tapers at an angle different from a taper in the inlet part of a passage through the valve seat. This causes shut off to occur at the rim edge of the passage through the valve seat where there is no erosion thereby assuring positive shut off after extended use. This tapering arrangement also assures virtually no erosion of the initial part of the valve seat passage increasing the uniform choke action of the nose piece. Still another variation relates to a concavely tapering section of the nose piece downstream of the internal throttling passages. Preferably special choke nose piece is combined with the erosion and corrosion resistant liners previously mentioned.
BRIEF DESCRIPTION OF THE DRAWING
The drawing is a cross-sectional view of the internal features of the flow line choke valve of this invention.
DETAILED DESCRIPTION OF THE INVENTION
Generally speaking, this invention is for a flow line choke control valve for oil and gas production and injection wells.
The drawing shows the choke control valve. The valve comprises valve body means 11 which maybe made of one or more structural elements to define by inner inlet surface 12 an inlet flow passage, and by inner chamber surface 13 a chamber flow passage, and by inner outlet surface 14 and outlet flow passage. Adjacent the point where the inner chamber flow passage defined by inner chamber valve body surface 13 communicates with the outlet flow passage defined by outlet inner body surface 14 is valve seat means 15 with a valve seat flow passage extending therethrough defined by tapering valve seat wall 16 starting at the chamber end of the flow passage and by nontapering valve seat wall 17. The tapering valve seat walls taper at a specific angle with respect to the center line or longitudinal axis of the valve seat means for reasons hereinafter described in detail. Surrounding the flow passage through valve seat chamber inlet end 18 has a substantially flat surface which is substantially perpendicular to the longitudinal axis of the valve seat means and which meets with tapering surface 16 at juncture 19 which as hereinafter described forms the shut off seat of the valve. The internal flow passage through the inlet, chamber, valve seat and outlet of the valves allow fluids to flow from inlet end 20 through the valve body to outlet end 21 in the direction shown. Inlet ends 20 and 21 are adapted in conventional fashion to be connected into a flowline. Typically, the flange type connection with seal means in depressions 22 and 23 and bolt holes 24, 25, 26 and 27 will be used.
Movably disposed within valve seat means 15 and the chamber or throat of the valve is valve throttle means 28 which is adapted to be moved into and out of the valve seat means and to control the rate of fluid flowing through the control valve. The means for moving the throttle into and out of valve seat forms no part of this invention, but for illustrative purposes the throttle means is shown connected to stem 29 which moves into and out of the valve by handle 30. The stem is supported by conventional chamber end plug means 31 with conventional stem sealing means 32 with stem sealing rings 33 and 34 and outer inner seal rings 35 and 36 and outer seal ring 37. The stem seals and plug means may be held in place in any conventional fashion, e.g., screw plugs, set screws etc. For illustrative purposes, it is shown held in place by threads 38. For illustrative purposes, typical nibolt type retention system 39 is shown.
Throttle means 28 is shown with optional enlarged chamber end 40. The throttle means is also shown with a nose piece defined by outer wall surface 41, tapering wall suface 42 and outlet end surface 43. Tapering wall surface 42 is preferably concavely shaped. The longitudinal length of nose piece surfaces 41 and 42 must be at least one half inch for reasons hereinafter made apparent. The nose piece has centrally located flow passage 44 extending longitudinally from outlet end 43 toward the chamber part of the valve body. This central nose piece flow passage communicates with at least one first throttling flow passage 45 which extends from central passage 44 outwardly through outer nontapering surface 41 of the nose piece to the flow passage passing through the valve seat means. Preferably central flow passage 44 will also communicate with at least one second throttling flow passage 46 which extends from the central flow passage outwardly through outer surface 41 of the nose piece to the flow passage passing through the valve seat means. Throttling flow passages 45 and 46 are shown in the form of a cross, but central flow passage 44 and throttling flow passage 45 and central flow passage 44 and throttling flow passage 46 may be T-shaped, L-shaped, Y-shaped or any other shape. The throttling flow passage or passages could also be a ring of 6 to 20 or more flow passages. A T-shape or double T-shape or a greater number of radial flow passages is preferred since this causes the greatest amount of radial fluid flow into the throttling passages and the greatest amount of fluid impinging on fluid to reduce erosion of the valve. For reasons hereinafter made apparent, first throttling flow passage 45 is adapated to conduct a greater rate of fluid flow than second throttling flow passage 46 and the inlet of the second throttling flow passage is paced longitudinally further from nose piece outlet end 43.
As shown, the cross section of the nose piece optionally tapers to a smaller size cross section starting at a point spaced longitudinally toward outlet end 21 of the valve body from first throttling flow passage 45. As previously noted, tapering surface 42 is preferably concavedly shaped for throttling. This reduces erosion in the valve seat and in the outlet of the valve. More importantly it lessens the chances of erosion of surface 16 and surface 17 of the valve seat means 15.
At a point longitudinally toward the chamber of the valves from second throttling passage 46, throttle means 28 tapers or enlarges to a larger predeterimined size which is larger than the flow passage through valve seat means 15. The taper is at a specified angle with respect to the centerline or longitudinal axis of the valve seat means. This angle of taper must be greater than the angle of taper of valve seat means tapering surface 16. In this way when throttle means 28 is moved into the valve seat means, tapering surface 47 of the throttle means is adapted to contact valve seat means 15 at rim juncture 19. This part of the valve seat means is not erroded thereby assuring positive shut off of the valve even after extended use.
Inside the outlet flow passage of the valve body defined by inner outlet body surface 14 is outlet liner means 48 having outer liner end 49 and inner liner end 50. The outlet liner has inner surface 51 defining a central outlet liner flow passage extending through outlet liner means 48. Outer surface 52 of the outlet liner and inner outlet surface 14 are adapted to define an outlet monitoring flow passage behind the liner. This flow passage is designed to permit monitoring for a hole or leak in outlet liner means 48. Communicating with this outlet monitoring passage is flow passage 53 through the outlet part of the valve body. The passage is monitored for fluids leaking through a hole in the liner. This may be accomplished in any known way, for example, pressure means, chemical means or electrical means. The test flow passage will be adapted accordingly. Near inner end 50 of outlet liner 48 is inner outlet liner sealing means 54 adapted to form a fluid tight seal between outer surface 52 of the liner and inner outlet surface 14 of the valve body. Any type of sealing means may be used, for example, seal rings, threads or tapered surfaces. Similarly near outer end 49 of liner 48 is outer oulet sealing means 55 adapted to form a fluid-tight seal between outer surface 52 of the liner and inner outlet surface 14 of the valve body. The type of seal used will depend on the final valve configuration. Usually seal rings like O-rings will be used. The sealed monitoring passage may be formed in any suitable fashion. It is preferred that the liner be press fitted into the valve body. Therefore, the monitoring flow passage is shown as being formed by a spiralling groove created around the outer surface of the liner.
In a similar fashion inside the inlet flow passage of the valve body defined by inner inlet body surface 12, there is shown optional inlet liner means 56 having outer liner end 57 and inner inlet liner end 58. The inlet liner has inner surface 59 defining a central inlet liner flow passage extending through inlet liner means 56. Outer surface 60 of the inlet liner and inner inlet surface 12 are adapted to define an inlet monitoring flow passage behind inlet liner means 56. This flow passage is designed to permit monitoring for a hole or leak in inlet liner means 56. Communicating with this inlet monitoring passage is flow passage 61 through the inlet part of the valve body. The passage is monitored for fluids leaking through the liner. This may be accomplished in any known way, for example, pressure means, chemical means or electrical means. This test flow passage will be adapted accordingly. Near inner end 58 of inlet liner means 56 is inner inlet sealing means 62 adapted to form a fluid tight seal between outer surface 60 of the liner and inner inlet surface 12 of the valve body. Any type of sealing means may be used, for example, seal rings, threads or tapered surfaces. Similarly near outer end 57 of liner 56 is outer inlet sealing means 63 adapted to form a fluid tight seal between outer surface 60 of the liner and inner inlet surface 12 of the valve body. The type of seal used will depend on the final valve configuration. Usually seal rings like O-rings will be used. The sealed monitoring passage way is formed in any suitable fashion. It is preferred that the liner be press fitted into the valve body. Therefore, the monitoring flow passage is shown as being formed by a spiralling groove created around the outer suface of the liner.
Optional chamber liner means 64 is shown inside chamber flow passage of the valve body defined by inner chamber body surface 13. The chamber liner means has ends 65 and 66 and inner surface 67 which defines a central chamber liner flow passage extending through chamber liner means 64. This flow passage communicates with the flow passage through valve seat means 15. Outer suface 69 of the chamber liner and inner chamber surface 13 of the valve body are adapted to define a chamber monitoring flow passage behind the liner. This flow passage is designed to permit monitoring for a hole or leak in chamber liner means 64. Communicating with this chamber monitoring passage is flow passage 69 through the chamber part of the valve body. The passage is monitored for fluids leaking through the liner. This may be accomplished in any known way, for example, pressure means, chemical means or electrical means. This test flow passage will be adapted accordingly. Near end 65 of the chamber liner means 64 is sealing means 70 adapted to form a fluid-tight seal between outer surface 68 of the liner and inner chamber surface 13 of the valve body. Similarly, near end 66 is sealing means 71 adapted to form a fluid-tight seal between outer surface 68 of the liner and inner chamber surface 13 of the valve body. Any type of sealing means may be used, for example, seal rings, threads or tapered surfaces. The type of seal used will depend on the final valve configuration. Usually seal rings like O-rings will be used. Chamber inlet liner means 64 has aperture 72 through the wall of the chamber liner means. The aperture communicates with the central flow passage in the liner and with the inlet flow passage in the inlet of the valve body or the central flow passage of inlet liner means 56 whichever is applicable. Surrounding aperture 72 is sealing means 73 adapted to form a fluid-tight seal between outer surface 68 of the chamber liner surfaces and inner surface 13 of the body. The sealed monitoring passage may be formed in any suitable fashion. The monitoring flow passage is shown as being formed by grooves around the outer surface of the liner. However, since aperture 72 interrupts the spiralling path, the spiralling grooves are shown interconnected by groove 74 running longitudinally of the liner.
The valve seat means, the throttle means and the liner may be made of erosion and corrosion resistant materials like tungsten carbide, stellite, stainless steels, such as 316 or 174-PH ceramics, 12 chromium, or other materials treated with a hardening process such as gas diffusion processes or coated or lined with these materials. Moreover, the surfaces may be coated with other corrosion resistant materials. In this way, the entire valve body or only the parts subjected to the greatest erosion may be trimmed with erosion-resistant materials and the continuity of the trim monitored for holes or leaks.
In operation, when the choke control valve is installed in the shut off position with fluid pressure in the inlet and chamber of the valve, fluid flow is prevented by contact between rim juncture 19 of valve seat means 15 and tapered surface 47 of throttle means 28. When valve stem 29 pulls the throttle means into valve chamber, the shut off seat is broken and fluid flows between tapered surface 16 of the valve seat means and tapered surface 47 of the throttle means. If the throttle means is moved far enough, the first throttling stage of the control valve is activated. This first stage is represented by smaller throttling flow passage 46 which communicates with central flow passage 44. Optional throttling flow passage 45 remains shut off by inner nontapering valve seat wall 17. Smaller throttling flow passage 46 acts like a fixed orifice and in most cases will be designed to give a right amount of small flow without partial eclipse. For example, the flow will be designed to prevent freezing or congealing of fluids inside the flow line. It is contemplated that this flow will be around 3% to 7% in rigidly cold areas. When the throttle means is opened, the fluid flows radially into flow passages 46. The fluid impinges upon itself at the juncture of flow passage 46 and central flow passage 44. This fluid on fluid impingement reduces erosion in the throttling means and dissipates some of the erosion energy in fluid before it passes through and out of central flow passage 44 to the outlet end of the valve.
When the throttle means is moved further out of valve seat means 15, the second stage of the choke control is activated as throttling flow passage 45 is moved past inner nontapering wall 17 and adjacent tapering wall 16. The second stage is of the same general design as the first stage but it is larger and flow through the second stage is combined with the fluid flowing in the smaller first stage. Moreover, fluid from the first stage impinges on fluid flowing radially in the second stage. The flow rate in the second stage can be fine tuned by eclipsing part of throttle flow passage 45. This second stage provides throttling action over flow rates ranging between the first stage and the other stages of the control valve. Other intermediate stages may be added by adding throttling flow passages.
When throttling means is moved further out of the valve seat, tapered surface 42, preferably concave, moves into the tapered area of valve seat means 15 and flow through the first and second states is combined with flow between the concave surface and inner surface nontapering valve seat surface 17 until the throttle means is completely out of the valve seat means. This reduces the chances of erosion of the throttling surfaces and provides virtually full range control with reduced erosion and corrosion. Any erosion that does occur will occur toward the outlet of the valve away from rim juncture 19, tapered surface 16, and the top part of nontapered surface 17 thereby assuring more reliable throttle and shut action of the valve over a longer period of time. There is also less pressure drop through the throttling means of the valve at full open, less direct solids impingement on valve surfaces, and the valve is self cleaning of solids. If erosion of one or more of the liners 48, 56 or 64 occurs and a hole is formed in a liner, fluid leaks into the appropriate monitoring passage which serve to conduct the fluid to the appropriate test arrangement through the wall of the valve body. All of the monitoring passages could be interconnected and only one test arrangement used, but use of three separate trim liners and monitoring flow passages helps to isolate the point of trouble if the valve is made up of separate parts.
Having illustrated and described embodiments of this invention in some detail, it will be understood that these descriptions and illustrations have been offered by way of example only and that the invention is to be limited in scope only by the appended claims.
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A flow line control valve is provided with internal erosion and corrosion trim liners and means for detecting for leaks in the liners. There is also provided fuller range, positive shutoff throttle means designed to reduce erosion and corrosion of the throttling parts and valve seat. The low flow rate throttling action is provided by progressive and accumulative flow through one or more stages of throttling flow passages of and by a nose end of the throttling means. Preferably the nose end is concavely tapered. Also preferably two or more stages of throttling spaced apart flow passages of increasing size are employed. Postive long lasting shut-off is assured by combining throttling and seat surfaces of different angles of taper.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the invention
[0002] The present application relates to a novel method for manufacturing a prostaglandin analogue which is used for active ingredients of pharmaceuticals.
[0003] 2. Art Related
[0004] Oxidation of hydroxyl group is an important reaction step to produce a prostaglandin analogue having keto group on the 5-membered ring and/or the omega chain of its prostanoic acid skeleton.
[0005] Swern oxidation that has been conventionally used for prostaglandin syntheses requires manufacturing equipment that can operate at a very low reaction temperature (−70 to −40C.). In addition, when the prostaglandin analogue has a carboxyl group in the molecular, protection of the carboxyl group is needed before Swern oxidation.
[0006] Traditional oxidation using heavy metal reagents such as chromic acid can be used for oxidation of compounds having carboxyl group. However, most of heavy metals are toxic and occasionally not suitable as industrial production methods for pharmaceuticals.
[0007] Although Dess-Martin oxidation also can, be used to oxidize compounds having carboxyl group, the heat- and shock-sensitivity of this oxidizing reagent is published (Chem Eng. News, July 16, 3, 1990, the cited reference is incorporated into the present application by reference). In addition, this oxidizing reagent is not easily available as an industrial raw material from the market.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide a new method for manufacturing a prostaglandin analogue having one or more keto groups on the 5-membered ring and/or the omega chain, which can be carried out easily under relatively mild conditions.
[0009] The present invention provides a method for manufacturing a prostaglandin analogue represented by formula (I):
wherein
wherein R1 is a protecting group for hydroxy group;
wherein R2 is a protecting group for hydroxy group;
wherein R3 is a protecting group for hydroxy group, R4 and R5 are hydrogen atom, halogen atom, lower alkyl or lower alkoxy group or when R4 and R5 are lower alkyl at the same time, R4 and R5 taken together may form a cyclic group,
provided that at least one of X 1 , Y 1 and Z 1 is;
A is —CH 3 , —CH 2 OH, —COCH 2 OH, —COOH or a functional derivative thereof;
B is a single bond, —CH 2 —, —CH 2 —CH 2 —, —CH═CH— or —C—C—, —CH 2 —CH 2 —CH 2 —, —CH═CH—CH 2 —, —CH 2 —CH═CH—, —C═C—CH 2 — or —CH 2 —C═C—;
Ra is bivalent saturated or unsaturated lower-medium aliphatic hydrocarbon group, which is unsubstituted or substituted by halogen atom, alkyl, hydroxy, oxo, aryl or heterocyclic group, provided that one or more carbon atoms of the aliphatic hydrocarbon group may optionally be replaced with oxygen, nitrogen or sulfur atom; and
Rb is hydrogen atom; saturated or unsaturated lower-medium aliphatic hydrocarbon group which may be substituted by halogen, oxo, hydroxy, lower alkoxy, lower alkanoyloxy, cyclo(lower)alkyl, cyclo (lower) alkyloxy, aryl, aryloxy, heterocyclic or heterocyclic oxy; cyclo(lower)alkyl; cyclo(lower)alkyloxy; aryl; aryloxy; heterocyclic; or heterocyclic oxy,
which comprises the step of, reacting a compound of formula (II):
wherein, X 2 is the same as X 1 except for when
Y 2 is the same as Y 1 except for when
Z 2 is the same as Z 1 except for when
provided that at least one of
and
A, B, Ra and Rb are the same as above;
with a co-oxidizer under the presence of a tetramethylpyperidine-1-oxyl derivative.
[0010] The compound of formula (I) can be used for manufacturing pharmaceuticals. (see, for example, U.S. Pat. Nos. 5,073,569, 5,166,174, 5,221,763, 5,212,324, 5,739,161 and 6,242,485 (the cited references are herein incorporated by reference)
DETAILED DESCRIPTION OF THE INVENTION
[0011] In the definition of above formulae, the term “unsaturated” in the definitions for Ra and Rb is intended to include at least one or more double bonds and/or triple bonds that are isolatedly, separately or serially present between carbon atoms of the main and/or side chains.
[0012] The term “lower-medium aliphatic hydrocarbon” means a hydrocarbon having a straight or branched chain of 1 to 14 carbon atoms, wherein the side chain has preferably 1 to 3 carbon atoms. The preferred Ra has 1 to 10, more preferably, 6 to 10 carbon atoms, and the preferred Rb has 1 to 10, more preferably, 1 to 8 carbon atoms.
[0013] The term “halogen” includes fluorine, chlorine, bromine, and iodine atoms.
[0014] The term “lower” means a group having 1 to 6 carbon atoms unless otherwise specified.
[0015] The term “lower alkyl” means a straight- or branched-chain saturated hydrocarbon group having 1 to 6 carbon atoms, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, and hexyl.
[0016] The term “lower alkoxy” means a lower alkyl-O— wherein the lower alkyl is as described above.
[0017] The term “lower alkanoyloxy” means a group represented by the formula RCO—O—, wherein RCO— is an acyl formed by oxidation of a lower alkyl as described above, for example, acetyl.
[0018] The term “lower cycloalkyl” means a group formed by cyclization of a lower alkyl group containing 3 or more carbon atoms as described above, for example, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.
[0019] The term “cyclo(lower)alkyloxy” means a group represented by the formula cycloalkyl-O—, wherein cycloalkyl is described above.
[0020] The term “aryl” includes aromatic hydrocarbon rings (preferably monocyclic groups), which may be substituted, for example, phenyl, tolyl and xylyl. Examples of the substituents in this case include halogen, and halogen substituted lower alkyl group, wherein halogen atom and lower alkyl group are as described above.
[0021] The term “aryloxy” means a group represented by the formula ArO—, wherein Ar is an aryl group as described above.
[0022] The term “heterocyclic” includes mono- to tri-cyclic, preferably monocyclic heterocyclic group which is 5 to 14, preferably 5 to 10 membered ring having optionally substituted carbon atom and 1 to 4, preferably 1 to 3 of 1 or 2 type of hetero atoms selected from nitrogen, oxygen and sulfur atoms. Examples of the heterocyclic group include furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, furazanyl, pyranyl, pyridyl, pyridazyl, pyrimidyl, pyrazinyl, 2-pyrrolinyl, pyrrolidinyl, 2-imidazolinyl, imidazolidinyl, 2-pyrazolinyl, pyrazolidinyl, piperidino, piperazinyl, morpholino, indolyl, benzothienyl, quinolyl, isoquinolyl, purinyl, quinazolinyl, carbazolyl, acridinyl, phenanthridinyl, benzimidazolyl, benzimidazolonyl, benzothiazolyl, phenothiazinyl. Examples of the substituent in this case include halogen, and halogen substituted lower alkyl group, wherein halogen atom and lower alkyl group are as described above.
[0023] The term “heterocyclic-oxy” means a group represented by the formula HcO—, wherein Hc is a heterocyclic group as described above.
[0024] The term “functional derivative” of A includes salts, preferably pharmaceutically acceptable salts, ethers, esters, and amides.
[0025] Examples of suitable “pharmaceutically acceptable salts” include nontoxic salts which are commonly used, and salts with inorganic bases, for example, alkali metal salts (sodium salt, potassium salt and the like); alkaline earth metal salts (calcium salt, magnesium salt and the like); ammonium salts; salts with organic bases, for example, amine salts (such as methylamine salt, dimethylamine salt, cyclohexylamine salt, benzylamine salt, piperidine salt, ethylenediamine salt, ethanolamine salt, diethanolamine salt, triethanolamine salt, tris(hydroxymethylamino)ethane salt, monomethyl-monoethanolamine salt, lysine salt, procaine salt, and caffeine salt); basic amino acid salts (such as arginine salt, and lysine salt); tetraalkyl ammonium salts and the like. These salts may be manufactured from, for example, corresponding acids and bases in accordance with a conventional manner or salt exchange.
[0026] Examples of the ethers include alkyl ethers, for example, lower alkyl ethers such as methyl ether, ethyl ether, propyl ether, isopropyl ether, butyl ether, isobutyl ether, t-butyl ether, pentyl ether and 1-cyclopropyl ethyl ether; and medium or higher alkyl ethers such as octyl ether, diethylhexyl ether, lauryl ether and cetyl ether; unsaturated ethers such as oleyl ether and linolenyl ether; lower alkenyl ethers such as vinyl ether, allyl ether; lower alkynyl ethers such as ethynyl ether and propynyl ether; hydroxy(lower)alkyl ethers such as hydroxyethyl ether and hydroxyisopropyl ether; lower alkoxy (lower)alkyl ethers such as methoxymethyl ether and 1-methoxyethyl ether; optionally substituted aryl ethers such as phenyl ether, tosyl ether, t-butylphenyl ether, salicyl ether, 3,4-di-methoxyphenyl ether and benzamidophenyl ether; and aryl(lower)alkyl ethers such as benzyl ether, trityl ether and benzhydryl ether.
[0027] Examples of the esters include aliphatic esters, for example, lower alkyl esters such as methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, t-butyl ester, pentyl ester, and 1-cyclopropylethyl ester; lower alkenyl esters such as vinyl ester, and allyl ester; lower alkynyl esters such as ethynyl ester, and propynyl ester; hydroxy(lower)alkyl esters such as hydroxyethyl ester; and lower alkoxy(lower)alkyl esters such as methoxymethyl ester, and 1-methoxyethyl ester as well as, for example, optionally substituted aryl esters such as phenyl ester, tosyl ester, t-butylphenyl ester, salicyl ester, 3,4-dimethoxyphenyl ester, and benzamidephenyl ester; and aryl(lower)alkyl esters such as benzyl ester, trityl ester, and benzhydryl ester.
[0028] An amide for A is a group represented by formula: —CONR′R″, wherein R′ and R″ independently represent hydrogen atom, lower alkyl, aryl, alkyl- or aryl-sulfonyl, lower alkenyl or lower alkynyl. Examples of amides include mono- or di-lower alkyl amides such as methylamide, ethylamide, and dimethylamide; aryl amides such as anilide, and toluidide; and alkyl- or aryl-sulfonyl amides such as methylsulfonyl amide, ethylsulfonyl amide, and tolylsulfonyl amide.
[0029] Preferred examples of A include —COOH, and a pharmaceutically acceptable salt, an ester and an amide thereof.
[0030] Preferred B is —CH 2 —CH 2 — which provides the structure of so-called, 13,14-dihydro type prostaglandin derivative.
[0031] Preferred Ra is a hydrocarbon having 1-10 carbon atoms, more preferably, 6-10 carbon atoms. One or more carbon atom of the hydrocarbon group may optionally be replaced with oxygen, nitrogen or sulfur atom
[0032] Examples of Ra include, for example, the following groups:
—CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —, —CH 2 —CH═CH—CH 2 —CH 2 —CH 2 —, —CH 2 —CH 2 —CH 2 —CH 2 —CH═CH—, —CH 2 —C≡C—CH 2 —CH 2 —CH 2 —, —CH 2 —CH 2 —CH 2 —CH 2 —CH (CH 3 )—CH 2 —, —CH 2 —CH 2 —CH 2 —CH 2 —O—CH 2 —, —CH 2 —CH═CH—CH 2 —O—CH 2 —, —CH 2 —C≡C—CH 2 —O—CH 2 —, —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —, —CH 2 —CH═CH—CH 2 —CH 2 —CH 2 —CH 2 —, —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —CH═CH—, —CH 2 —C≡C—CH 2 —CH 2 —CH 2 —CH 2 —, —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —CH(CH 3 )—CH 2 —, —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —, —CH 2 —CH═CH—CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —, —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —CH═CH—, —CH 2 —C≡C—CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —, —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —CH 2 —CH (CH 3 )—CH 2 —,
[0050] Preferred Rb is hydrogen atom or a hydrocarbon containing 1-10 carbon atoms, more preferably, 1-8 carbon atoms and, which may be substituted by halogen atom such as fluorine.
[0051] In the specification and claims, the term “a protecting group for hydroxy” means a functional group which is introduced to protect the hydroxy group from oxidization. In the present invention, the protecting group may be any group as long as it can act as such. Examples of the protecting groups may include methyl, methoxymethyl, ethyl, 1-ethoxyethyl, benzyl, substituted benzyl, allyl, tetrapyranyl, t-butyldimethylsilyl, triethylsilyl, triisopropylsilyl, diphenylmethylsilyl, formyl, acetyl, substituted acetyl, benzoyl, substituted benzoyl, methyloxycarbonyl, benzyloxycarbonyl, t-buthloxycarbonyl and allyloxycarbonyl groups.
[0052] The compound of formula(II) used in the present invention has been known to the art and may be obtained by any known means for preparing prostaglandin analogues. For example, U.S. Pat. Nos. 5,073,569, 5,166,174, 5,221,763, 5,212,324, 5,739,161 and 6,242,485(the cited references are herein incorporated by reference) disclose a compound of formula (II) having an OH— group and a method for preparing the same as an intermediate or an objective substance.
[0053] Examples of the tetramethylpiperidine-1-oxyl derivative used in the present invention may include 2,2,6,6,-tetramethylpiperidine-1-oxyl (TEMPO), 4-hydroxy-2,2,6,6,-tetramethylpiperidine-1-oxyl, 4-amino-2,2,6,6,-tetramethylpiperidine-1-oxyl, 4-oxo-2,2,6,6,-tetramethylpiperidine-1-oxyl, 4-methoxy-2,2,6,6,-tetramethylpiperidine-1-oxyl, 4-acetoamide 2,2,6,6,-tetramethylpiperidine-1-oxyl, 4-carboxy-2,2,6,6,-tetramethylpiperidine-1-oxyl, 4-cyano 2,2,6,6,-tetramethylpiperidine-1-oxyl and 4-acetylamino 2,2,6,6,-tetramethylpiperidine-1-oxyl.
[0054] The amount of the tetramethylpiperidine-1-oxyl derivative used in the reaction may be about 0.001-5.0 mole, preferably about 0.001-0.2 mole per one molar equivalent of the hydroxyl group of the starting compound to be oxidized or a compound of formula (II).
[0055] The co-oxidizer used in the present invention may be any as long as it can convert the tetramethylpiperidine-1-oxyl derivative into the active form. Examples of co-oxidizers may include hypohalogenous acid such as hypochlorous acid or a salt thereof, halogenous acid such as bromous acid or a salt thereof, compounds having polyvalent iodine such as iodobenzene acetate, peroxides such as 3-chloro-perbenzoidc acid, N-halogen substituted succinimides such as N-chloro succinimide.
[0056] The amount of the co-oxidizer in the reaction may be 1.1-3 molar equivalents, preferably 1.1-2 molar equivalents and more preferably 1.1-1.5 molar equivalent per one molar equivalent of the hydroxy group to be oxidized.
[0057] The reaction may be conducted in an organic solvent, an aqueous solvent, a mixture thereof, or a two-phase solvent system consisting of an organic and an aqueous solvents.
[0058] Examples of organic solvents used in the present invention may be aromatic hydrocarbon solvent such as toluene, aliphatic hydrocarbon solvent such as hexane, halogen containing solvent such as dichloromethane, ketones such as acetone, esters such as ethyl acetate.
[0059] The aqueous solvent may contain a pH adjusting agent such as sodiumhydrogen carbonate, pH buffering such as potassium dihydrogen phosphate and sodium dihydrogen phosphate.
[0060] According to the present invention, a halogenated salt such as sodium bromide, potassium bromide, tetrabutylammonium bromide, and tetrabuthlammonium chloride may be added to the reaction in order to facilitate the reaction. The amount of the halogenated salt to be added is not limited and may be about 1.0-2.0 molar equivalents per one molar equivalent of the hydroxyl group to be oxidized.
[0061] In the present invention, the alcohol compound of formula (II) is reacted with the co-oxidizer under the presence of the tetramethylpiperidine-1-oxyl derivative. According to the present invention, the reaction may be carried out at a temperature of −10 to 50° C., preferably, about 0 to 20° C.
[0062] The present invention will be illustrated in more detail by way of the following examples. These examples should not be used as any limitation of the present invention.
EXAMPLE 1
[0063]
[0064] An alcohol compound (1) 0.102 g (0.20 mmol) was dissolved in ethyl acetate 0.69 ml, and TEMPO in ethyl acetate 0.313 ml (10 mg/ml, 0.02 mmol) was added thereto. The mixture was cooled to 0C. Three percent aqueous sodium hydrogen carbonate 0.56 ml (0.2 mmol) and potassium bromide 23.8 mg (0.20 mmol) were added thereto. About 0.9M aqueous sodium hypochlorite 0.27 ml (0.24 mmol) was added dropwise to the reaction, and the mixture was stirred for 30 minutes at 0° C. and added with saturated aqueous sodium thiosulfate. Then, the reaction mixture was extracted three times with ethyl acetate. The extract was washed with dilute hydrochloric acid, saturated aqueous sodium hydrogen carbonate and brine, dried with anhydrous magnesium sulfate, filtered and concentrated under vacuum. The residue was purified with silica gel flash chromatography (column: BW-300 60 g, ethyl acetate-hexane 30:/0) to give the desired compound (2) as colourless-oil. Yield 0.101 g (99.3%).
[0065] 1 H NMR (200 MHz in CDCl 3 , TMS=0 ppm) δ 0.88 (3H, t, J=6.5 Hz) 1.24 (6H, t, J=6.5 Hz) 1.20-2.80 (36H, m) 2.25 (2H, t, J=7.6 Hz) 3.41-3.60 (1H, m) 3.74-3.98 (1.5H, m) 4.14 (0.5H, q, J=7.0 Hz) 4.54-4.60 (0.5H, m) 4.64-4.71 (0.5H, m) 5.00 (1H, septet, J=6.2 Hz)
EXAMPLE 2
[0066]
[0067] An alcohol compound (3) 0.172 g (0.361 mmol) was dissolved in toluene 1.25 ml, potassium bromide 43 mg (0.36 mmol) was added thereto and the mixture was cooled to 0° C. Neutral phosphate buffer 3.6 ml and TEMPO in toluene 0.56 ml (10 mg/ml, 0.0361 mmol) were added thereto. About 0.9M aqueous sodium hypochlorite 0.48 ml (0.433 mmol) was added dropwise to the reaction, and the mixture was stirred for 20 minutes at 0° C. Saturated aqueous sodium thiosulfate and 1N hydrochloric acid 0.36 ml were added to the reaction. Then, the reaction mixture was extracted three times with ethyl acetate. The extract was washed with water and dilute hydrochloric acid, dried with anhydrous magnesium sulfate, filtered and concentrated under vacuum. The residue was purified with silicagel column (column: FL-60D, 36 g) to give the desired compound (4) as colourless oil. Yield 0.161 g (94.0%).
[0068] 1 H NMR (200 MHz in CDCl 3 , TMS=0 ppm) δ 0.92 (3H, t, J=7.0 Hz) 1.11-2.45 (29H, m) 2.34 (2H, t, J=7.3 Hz) 2.65-3.11 (3H, m) 3.42-3.60 (1H, m) 3.75-3.97 (1.5H, m) 4.16 (0.5H, q, J=7.3 Hz) 4.54-4.65 (0.5H, m) 4.65-4.74 (0.5H, m)
EXAMPLE 3
[0069]
[0070] An alcohol compound (5) 0.107 g (0.20 mmol) was dissolved in toluene 0.38 ml, and TEMPO in toluene 0.62 ml (10 mg/ml, 0.04 mmol) was added thereto. The mixture was cooled to 0° C. Three percent aqueous sodium hydrogen carbonate 0.56 ml(0.2 mmol) and potassium bromide 23.8 mg (0.20 mmol) were added thereto. About 0.9M aqueous sodium hypochlorite 0.27 ml (0.24 mmol) was added dropwise to the reaction, and the mixture was stirred for 45 minutes at 0° C. After that, the reaction mixture was added with saturated aqueous sodium thiosulfate and then, extracted three times with ethyl acetate. The extract was washed with dilute hydrochloric acid, saturated aqueous sodium hydrogen carbonate and brine, dried with anhydrous magnesium sulfate, filtered and concentrated under vacuum. The residue was purified with silica gel flash chromatography (column: BW-300 70 g, ethyl acetate-hexane 25:75) to give the desired compound (6) as colourless oil. Yield 0.102 g (95.7%).
[0071] 1 H NMR (200 MHz in CDCl 3 , TMS=0 ppm) δ 0.92 (3H, t, J=7.1 Hz) 1.11-2.13 (26H, m) 2.03 (3H, s) 2.30 (2H, t, J=7.4 Hz) 2.13-2.44 (3H, m) 2.73-3.15 (3H, m) 3.40-3.55 (1H, m) 3.62-4.00 (2H, m) 3.67 (3H, s) 4.47-4.60 (1H, m) 5.01-5.13 (1H, m)
EXAMPLE 4
[0072]
[0073] An alcohol compound (7) 0.114 g (0.20 mmol) was dissolved in toluene 0.38 ml, and TEMPO in toluene 0.62 ml (10 mg/ml, 0.04 mmol) was added thereto. The mixture was cooled to 0° C. Three percent aqueous sodium hydrogen carbonate 1.12 ml (0.4 mmol) and potassium bromide 48 mg (0.40 mmol) were added thereto. About 0.9M aqueous sodium hypochlorite 0.54 ml (0.48 mmol) was added dropwise to the reaction, and the mixture was stirred for 30 minutes at 0° C. After that, the reaction mixture was added with saturated aqueous sodium thiosulfate and then, extracted three times with ethyl acetate. The extract was washed with dilute hydrochloric acid, saturated aqueous sodium hydrogen carbonate and brine, dried with anhydrous magnesium sulfate, filtered and concentrated under vacuum. The residue was purified with silica gel flash chromatography (column: BW-300 70g, ethyl acetate-hexane 30:70) to give the desired compound (8) as colourless oil. Yield 0.107 g (94.7%).
[0074] 1 H NMR (200 MHz in CDCl 3 , TMS=0 ppm) δ 0.92 (3H, t, J=7.1 Hz) 1.14-2.45 (27H, m) 2.35 (2H, t, J=7.5 Hz) 2.62-3.10 (3H, m) 3.43-3.60 (1H, m) 3.74-3.95 (1.5H, m) 4.15 (0.5H, q, J=7.5 Hz) 4.54-4.63 (0.5H, m) 4.63-4.72 (0.5H, m) 5.11 (2H, s) 7.29-7.43 (5H, m)
EXAMPLE 5
[0075]
[0076] An alcohol compound (9) 0.204 g (0.509 mmol) was dissolved in dichloromethane anhydrous 15 ml, and TEMPO in toluene 0.796 ml (10 mg/ml, 0.0509 mmol) was added thereto. Solid [bis(acetoxy)iodo]benzene (BAIB) 0.180 g (0.560 mmol) was added to the mixture and the mixture was stirred for 6 hours at room temperature. After that, saturated aqueous sodium thiosulfate was added to the reaction and the reaction mixture was extracted three times with ethyl acetate. The extract was washed with dilute hydrochloric acid, saturated aqueous sodium hydrogen carbonate and brine, dried with anhydrous magnesium sulfate, filtered and concentrated under vacuum. The residue was purified with silica gel flash chromatography (column: BW-300 80 g, ethyl acetate-hexane 20:80) to give the desired compound (10) as colourless oil. Yield 0.190 g (93.6%).
[0077] 1 H NMR (200 MHz in CDCl 3 , TMS=0 ppm) δ 1.10-2.48 (19H, m) 2.07 (3H, s) 2.29 (2H, t, J=7.42 Hz) 2.76-3.07 (1H, m) 3.36-3.56 (1H, m) 3.66 (3H, s) 3.74-3.88 (1H, m) 4.31-4.50 (1H, m) 4.50-4.63 (1H, m) 5.08-5.21 (1H, m) 9.78 (1H, dd, J=3.0, 10.2 Hz)
COMPARATIVE EXAMPLE 1
[0078]
[0079] Oxalyl chloride 0.61 ml (6.99 mmol) was dissolved in dichloromethane 7 ml and the solution was cooled to −78° C. DMSO 0.99 ml (13.98 mmol) was added slowly dropwise thereto and the mixture was stirred for 10 minutes. The alcohol compound (11) 1.05 g (2.33 mmol) in dichloromethane was added dropwise thereto and the reaction mixture was stirred for 1 hour. After that, triethylamine 2.03 ml (14.56 mmol) was added dropwise to the reaction and stirred for further 1 hour at 0° C. Then, water was added to the reaction and the reaction mixture was extracted with dichloromethane. The extract was washed with brine, dried with anhydrous magnesium sulfate, filtered and concentrated under vacuum. The residue was purified with silica gel flash chromatography (column: Merck 7734 40 g, ethyl acetate-hexane 20:80) to give the desired methylthioester (12). Yield 1.15g (94.0%)
[0080] 1 H NMR (200 MHz in CDC13, TMS=0 ppm) δ0.88 (3H, t, J=6.8 Hz) 1.27 (6H, bs) 2.24 (3H, s) 1.45-2.82 (27H, m) 3.43-3.59 (1H, m) 3./4-3.90 (1H, m) 3.92 (0.5H, q, J=6.8 Hz) 4.16 (0.5H, q, J=6.8 Hz) 4.57 (0.5H, bs) 4.67 (0.5H,bs) 5.13 (3H, s) 5.28-5.54 (2H, m)
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The present invention provides a new method for manufacturing a prostaglandin analogue having one or more keto groups on the 5-membered ring and/or omega chain, which comprises the step of treating a corresponding hydroxyl group containing compound with a co-oxidizer under the presence of a tetramethylpyperidine- 1 -oxyl derivative to form the desired prostaglandin analogue. The method of the invention can be carried out easily under relatively mild conditions.
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RELATED APPLICATIONS
[0001] This application relates to, claims the benefit of the filing date of, and incorporates by reference, the U.S. patent application Ser. No. 08/922,898 entitled “System and Process for Object Rendering on Thin Client Platforms,” having inventors Bo Wu and Ling Lu, filed Sep. 3, 1997.
COPYRIGHT DISCLAIMER
[0002] A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright 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 rights whatsoever.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention generally relates to a method of providing full feature program processing according to a variety of standard language codes such as HTML, JAVA and other standard languages, for execution on a thin client platform. More particularly the invention relates to methods for compiling and rendering full feature standard HTML and JAVA programs into a format which is efficient for a limited processing resource platforms.
[0005] 2. Description of Related Art
[0006] Standard HTML and JAVA programs, and other hypertext languages, are designed for computers having a significant amount of data processing resources, such as CPU speed and memory bandwidth, to run well. One feature of these object specifying languages is the ability to specify a graphic object for display using relative positioning. Relative positioning enables the display of the graphic object on displays having a wide range of dimensions, resolutions, and other display characteristics. However, relative positioning of graphic objects requires that the target device have computational resources to place the graphic object on the display at specific coordinates. Thus, there are a number of environments, such as TV set top boxes, hand held devices, digital video disk DVD players, compact video disk VCD players or thin network computer environments in which these standard object specifying languages are inefficient or impractical. The original HTML and JAVA programs run very slowly, or not at all, in these types of thin client environments. To solve these problems, simpler versions of HTML and JAVA have been proposed, which have resulted in scripting out some of the features. This trades off some of the nice functionality of HTML and JAVA, which have contributed to their wide acceptance. Furthermore, use in thin client environments of the huge number of files that are already specified according to these standards, is substantially limited.
SUMMARY OF THE INVENTION
[0007] The present invention provides a system and method for processing an Display object specified by an object specifying language such as HTML, JAVA or other languages relying on relative positioning, that require a rendering program utilizing a minimum set of resources, for use in a target device that has limited processing resources unsuited for storage and execution of the HTML rendering program, JAVA virtual machine, or other rendering engine for the standard. Thus, the invention can be characterized as a method for storing data concerning such an object that includes first receiving a data set specifying the object according to the object specifying language, translating the first data set into a second data set in an intermediate object language adapted for a second rendering program suitable for rendering by the target device that utilizes actual target display coordinates. The second data set is stored in a machine readable storage device, for later retrieval and execution by the thin client platform.
[0008] The object specifying language according to alternative embodiments comprises a HTML standard language or other hypertext mark up language, a JAVA standard language or other object oriented language that includes object specifying tools.
[0009] The invention also can be characterized as a method for sending data concerning such an object to a target device having limited processing resources. This method includes receiving the first data set specifying the object according to the first object specifying language, translating the first data set to a second data set in an intermediate object language, and then sending the second data set to the target device. The target device then renders the object by a rendering engine adapted for the intermediate object language. The step of sending the second data set includes sending the second data set across a packet switched network such as the Internet or the World Wide Web to the target device. Also, the step of translating according to one aspect of the invention includes sending the first data set across a packet switched network to a translation device, and executing a translation process on the translation device to generate the second data set. The second data set is then transferred from the translation device, to the target device, or alternatively from the translation device back to the source of the data, from which it is then forwarded to the target device.
[0010] According to other aspects of the invention, the step of translating the first data set includes first identifying the object specifying language of the first data set from among a set of object specifying languages, such as HTML and JAVA. Then, a translation process is selected according to the identified object specifying language.
[0011] According to yet another aspect of the invention, before the step of translating the steps of identifying the target device from among a set of target devices, and selecting a translation process according to the identified target device, are executed.
[0012] In yet another alternative of the present invention, a method for providing data to a target device is provided. This method includes requesting for the target device a first data set from a source of data, the first data set specifying the object according to the object specifying language; translating the first data set to a second data set in an intermediate language adapted for execution according to a second rendering program by the target device. The second data set is then sent to this target device. This allows a thin platform target device to request objects specified by full function HTML, JAVA and other object specifying languages, and have them automatically translated to a format suitable for rendering in the thin environment.
[0013] Thus, the present invention provides a method which uses a computer to automatically compile standard HTML, JAVA and other programs so that such programs can run both CPU and memory efficiently on a thin client platform such as a TV set top box, a VCD/DVD player, a hand held device, a network computer or an embedded computer. The automatic compilation maintains all the benefits of full feature HTML and JAVA or other language.
[0014] The significance of the invention is evident when it is considered that in the prior art, standard HTML and JAVA were reduced in features or special standards are created for the thin client environment. Thus according to the prior art approaches, the standard programs and image files on the Internet need to be specially modified to meet the needs of special thin client devices. This is almost impossible considering the amount of HTML and JAVA formatted files on the Web. According to the invention each HTML file, compiled JAVA class file or other object specifying language data set is processed by a standard full feature HTML browser JAVA virtual machine, or other complementary rendering engine, optimized for a target platform on the fly, and then output into a set of display oriented language codes which can be easily executed and displayed on a thin client platform. Furthermore, the technique can use in general to speed up the HTML and JAVA computing in standard platforms.
[0015] Other aspects and advantages of the present invention can be seen upon review of the figures, the detailed description and the claims which follow.
BRIEF DESCRIPTION OF THE FIGURES
[0016] FIG. 1 is a simplified diagram of a end user thin platform for execution of a compiled code data source according to the present invention.
[0017] FIG. 2 is a simplified diagram of a user workstation and server for precompiling a composed data set according to the present invention.
[0018] FIG. 3 is a simplified diagram of a precompiler for a HTML formatted file.
[0019] FIG. 4 is a simplified diagram of a precompiler for a JAVA coded program.
[0020] FIG. 5 is a class inheritance hierarchy for a precompiler for HTML.
[0021] FIG. 6 is a flow chart for the HTML precompiler process.
[0022] FIG. 7 illustrates the compiled HTML structure according to one embodiment of the present invention.
[0023] FIG. 8A -8B illustrate a compiled HTML run time engine for execution on the thin platform according to the present invention.
[0024] FIG. 9 is a flow chart of the process for precompiling a JAVA program according to the present invention.
[0025] FIG. 9A is a flow chart of one example process for translating the byte codes into a reduced byte code in the sequence of FIG. 9 .
[0026] FIG. 10 is a schematic diagram illustrating use of the present invention in the Internet environment.
[0027] FIG. 11 is a schematic diagram illustrating use of the present invention in a “network computer” environment.
[0028] FIG. 12A is a schematic diagram illustrating use of the present invention in an off-line environment for producing a compiled format of the present invention and saving it to a storage medium.
[0029] FIG. 12B illustrates the off-line environment in which the stored data is executed by thin platform.
DETAILED DESCRIPTION
[0030] A detailed description of preferred embodiments of the present invention is provided with respect to FIGS. 1-12A and 12 B. FIGS. 1-2 illustrated simplified implementation of the present invention. FIGS. 3-9 and 9 A illustrate processes executed according to the present invention. FIGS. 10-12A and 12 B illustrate the use of the present invention in the Internet environment or other packet switched network environment.
[0031] FIG. 1 illustrates a “thin” platform which includes a limited set of data processing resources represented by box 10 , a display 11 , and a “compiled code” rendering engine 12 for a display oriented language which relies on the data processing resources 10 . The end user platform 10 is coupled to a compiled code data source 13 . A compiled code data sources comprises, for example a VCD, a DVD, or other computer readable data storage device. Alternatively, the compiled code data source 13 consists of a connection to the World Wide Web or other packet switched or point-to-point network environment from which compiled code data is retrieved.
[0032] The limited data processing resources of the thin platform 10 include for example a microcontroller and limited memory. For example, 512 k of RAM associated with a 8051 microcontroller, or a 66 MHz MIPS RISC CPU and 512 k of dynamic RAM may be used in a representative thin platform. Other thin user platforms use low cost microprocessors with limited memory. In addition, other thin platforms may comprise high performance processors which have little resources available for use in rendering the compiled code data source. Coupled with the thin platform is a compiled code rendering engine 12 . This rendering engine 12 is a relatively compact program which runs efficiently on the thin platform data processing resources. The rendering engine translates the compiled code data source data set into a stream of data suitable for the display 11 . In this environment, the present invention is utilized by having the standard HTML or JAVA code preprocessed and compiled into a compiled HTML/JAVA format according to the present invention using the compiler engine described in more detail below on a more powerful computer. The compiled HTML/JAVA codes are saved on the storage media. A small compiled HTML/JAVA run time engine 12 is embedded or loaded into the thin client device. The run time engine 12 is used to play the compiled HTML/JAVA files on the thin platform 10 . This enables the use of a very small client to run full feature HTML or JAVA programs. The machine can be used both online, offline or in a hybrid mode.
[0033] FIG. 2 illustrates the environment in which the compiled code data is generated according to the present invention. Thus for example, a developer workstation 20 is coupled with image rendering tools such as HTML, JAVA, or other image tools 21 . The workstation 20 is coupled to a server for the composed data 22 . The server includes a precompiler 23 which takes the composed data and translates it into the compiled code data. Compiled code data is then sent to a destination 24 where it is stored or rendered as suits the needs of a particular environment. Thus for example, the destination may be a VCD, DVD or the World Wide Web.
[0034] According to the environment of FIG. 2 compiled HTML and JAVA “middleware” is implemented on an Internet server. Thus the thin set top box or other compiled code data destination 24 is coupled to the Internet/Intranet through the compiled HTML/JAVA middleware 22 , 23 . A small compiled HTML/JAVA run time engine is embedded in the thin destination device. All the HTML/JAVA files created in the workstation 20 go through the middleware server 22 to reach the thin client devices. The HTML/JAVA files are converted to the compiled format on the fly by the precompiler 23 on the middleware server 22 . The server 22 passes the compiled code onto the destination device. This allows for most software updates of precompiler techniques to be made in the server environment without the need to update the destination devices. Also, any changes in the run time engine that need to be executed in the destination device 24 can be provided through the link to the server 22 .
[0035] FIGS. 3 and 4 illustrate simplified diagrams of the precompilers for HTML and JAVA respectively. In FIG. 3 , standard HTML files are received at input 500 and applied to a HTML parser 501 . The output of the parser is applied to a command module 502 which includes a HTML rendering engine 503 , and memory resident HTML objects optimizing engine 504 . The output consists of the compiled HTML output engine 505 generates the output with simplified graphics primatives.
[0036] The basic class inheritance hierarchy for the HTML precompiling is shown in FIG. 5 . The process of translating a HTML file to the compiled HTML structure of the present invention is illustrated in FIG. 6 . The process begins at point 800 in FIG. 6 . The first step involves loading the HTML file into the rendering device. Next information concerning the target device is loaded (step 820 ). The HTML file is then parsed by searching for HTML tags, and based on such tags creating the class structure of FIG. 5 (step 830 ).
[0037] Using the parameters of the target device, and the parsing class structure set up after the parsing process, the algorithm does HTML rendering based on a class hierarchy adapted to the dimensions and palette of the target device (step 840 ). This fixes the coordinates of all the graphic objects specified by the HTML code on the screen of the target device. For example, the paragraphs are word wrapped, horizontal rules are placed in particular places, the colors are chosen, and other device specific processes are executed.
[0038] After the rendering, all the display information is saved back into the class structure of FIG. 5 . Finally the process goes through the class hierarchy and outputs the rendering information in compiled HTML format (step 850 ). The compiled HTML instructions are primitives that define rectangles, text, bitmaps and the like and their respective locations. After outputting the compiled instructions, the process is finished (step 860 ).
[0039] A simplified pseudo code for the HTML compilation process is provided in Table 1.
TABLE 1 Copyright EnReach 1997 function convert_html (input : pointer) : chtmlfile; // this takes a pointer to an HTML file and translates it into a CHTML binary file begin deviceInfo := LoadDeviceInfo( ); // Loads size and colors of target device Parse HTML file // use a parser to break the HTML file up into // tags represented in a fashion suitable for display For each HTML tag (<IMG ...> = 1 tag, <P> a paragraph </P> = 1 tag), select a sequence of CHTML instructions to render the tag on the output device. As instructions are selected, colors and positioning are optimized based on the device size and palette. CHTML instructions include: TITLE string TEXT formatted text at a specific position, complex formatting will require multiple CHTML TEXT instructions IMAGE image information including image-map, animation info, image data ANCHOR HTML reference Basic geometric instructions such as: SQUARE, FILLEDSQUARE, CIRCLE, FILLEDCIRCLE, and LINE, permit the complex rendering required by some HTML instructions to be decomposed into basic drawing instructions. For example, the bullets in front of lists can be described in CHTML instructions as squares and circles at specific locations. CHTML instructions including TEXT and IMAGE instructions can be contained within anchors. The CHTML compiler must properly code all instructions to indicate if an instruction is contained in an anchor. The CHTML instructions can then be written to the output file along with some header information. end;
[0040] Table 2 sets forth the data structure for the precompiling process.
TABLE 2 Copyright EnReach 1997 /* HTML font structure */ typedef struct tagHTMLFont { char name[64]; int size; int bold; int italic; int underline; int strikeout; } HTMLFont; /* FG point structure */ typedef struct tagFGPoint { int fX; int fY; } FGPoint; /* FG rectangle structure */ typedef struct tagFGRect { int fLeft; int fTop; int fRight; int fBottom; } FGRect; /* html node types, used by hType attribute in HTML_InfoHead structure */ #define HTML_TYPE_TITLE 0 /* title of the html page */ #define HTML_TYPE_TEXT 1 /* text node */ #define HTML_TYPE_CHINESE 2 /* Chinese text node */ #define HTML_TYPE_IMAGE 3 /* image node */ #define HTML_TYPE_SQUARE 4 /* square frame */ #define HTML_TYPE_FILLEDSQUARE 5 /* filled square */ #define HTML_TYPE_CIRCLE 6 /* circle frame */ #define HTML_TYPE_FILLEDCIRCLE 7 /* filled circle */ #define HTML_TYPE_LINE 8 /* line */ #define HTML_TYPE_ANCHOR 9 /* anchor node */ #define HTML_TYPE_ANIMATION 10 /* animation node */ #define HTML_TYPE_MAPAREA 11 /* client side image map area node */ /* header info of compiled html file */ typedef struct tagHTML_FileHead { unsigned int fBgColor; /* background color index */ unsigned int fPaletteSize; /* size of palette */ } HTML_FileHead; /* header info of each html node */ typedef struct tagHTML_InfoHead { unsigned int hType; /* type of the node */ unsigned int hSize; /* size of htmlInfo */ } HTML_InfoHead; /* html info structure */ typedef struct tagHTML_Info { HTML_InfoHead htmlHead; /* header info */ unsigned char htmlInfo[1]; /* info of the html node */ } HTML_Info; /* html title structure */ typedef struct tagHTML_Title { unsigned int textLen; /* length of text buffer */ char textBuffer[1]; /* content of text buffer */ } HTML_Title; /* html text structure */ typedef struct tagHTML_Text { FGPoint dispPos; /* display coordinates */ int anchorID; /* anchor id if it's inside an anchor, −1 if not */ HTMLFont textFont; /* font of the text */ unsigned int textColor; /* color index of the text */ unsigned int textLen; /* length of text buffer */ char textBuffer[1]; /* content of text buffer */ } HTML_Text; /* html Chinese structure */ typedef struct tagHTML_Chinese { FGPNT dispPos; /* display coordinates */ int anchorID; /* anchor id if it's inside an anchor, −1 if not */ unsigned int textColor; /* color index of the text */ unsigned int bufLen; /* length of the bitmap buffer (16 * 16) */ char textBuffer[1]; /* content of text buffer */ } HTML_Chinese; /* html image structure */ typedef struct tagHTML_Image { FGRect dispPos; /* display coordinates */ int anchorID; /* anchor id if it's inside an anchor, −1 if not */ int animationID; /* animation id if it supports animation, −1 if not */ int animationDelay; /* delay time for animation */ char mapName[64]; /* name of client side image map, empty if no image map */ void *data; /* used to store image data */ unsigned int fnameLen; /* length of the image file name */ char fname[1]; /* image filename */ } HTML_Image; /* square structure */ typedef struct tagHTML_Square { FGRect dispPos; /* display coordinates */ unsigned int borderColor; /* bordercolor index */ } HTML_Square; /* filled square structure */ typedef struct tagHTML_FilledSquare { FGRect dispPos; /* display coordinates */ unsigned int brushColor; /* the inside color index */ } HTML_FilledSquare; /* circle structure */ typedef struct tagHTML_Circle { FGRect dispPos; /* display coordinates */ unsigned int borderColor; /* border color index */ } HTML_Circle; /* circle structure */ typedef struct tagHTML_FilledCircle { FGRect dispPos; /* display coordinates */ unsigned int brushColor; /* the inside color index */ } HTML_FilledCircle; /* line structure */ typedef struct tagHTML_Line { FGPoint startPos; /* line starting position */ FGPoint endPos; /* line end position */ int style; /* style of the line (solid, dashed, dotted, etc.) */ unsigned int penColor; /* pen color index */ } HTML_Line; /* anchor structure */ typedef struct tagHTML_Anchor { int anchorID; /* id of the anchor */ unsigned int hrefLen; /* length of href */ char href[1]; /* url of the anchor */ } HTML_Anchor; /* animation structure */ typedef struct tagHTML_Animation { int animationID; /* id of the animation */ unsigned int frameTotal; /* total number of animation frames */ long runtime; /* animation runtime */ }HTML_Animation; #define SHAPE_RECTANGLE 0 #define SHAPE_CIRCLE 1 #define SHAPE_POLY 2 /* image map area structure */ typedef struct tagHTML_MapArea { char mapName[64]; /* name of client side image map */ int shape; /* shape of the area */ int numVer; /* number of vertix */ int coords[6][2]; /* coordinates */ unsigned int hrefLen; /* length of href */ char href[1]; /* url the area pointed to */ } HTML_MapArea;
[0041] An example routine for reading this file into the thin platform memory follows in Table 3.
TABLE 3 Copyright EnReach 1997 reading this file: #define BLOCK_SIZE 256 /* returns number of nodes */ long read_chm(const char *filename, /* input: .chm file name */ HTML_Info ***ppNodeList, /* output: array of (HTML_Info *) including anchors */ YUVQUAD **ppPalette, /* output: page palette */ unsigned int *palette_size) /* output: palette size */ { int fd; char head[12]; long total_nodes = 0; long max_nodes = 0; HTML_FileHead myFileHead; HTML_InfoHead myInfoHead; HTML_Info *pNodeInfo; void *pNodeData; long i; HTML_InfoHead *pHead; if (!ppNodeList ∥ !ppPalette ∥ !palette_size) return 0; (*ppNodeList) = NULL; (*ppPalette) = NULL; (*palette_size) = 0; /* open file */ fd = _open(filename, _O_BINARY | _O_RDONLY); if(fd < 0) return 0; /* read header and check for file type */ if(_read(fd,head, 10) != 10) { _close(fd); return 0; } if (strncmp(head, “<COMPHTML>”, 10)) { _close(fd); return 0; } /* read file header */ if (_read(fd, &myFileHead, sizeof(HTML_FileHead)) != sizeof(HTML_FileHead)) { {_close(fd); return 0; } (*palette_size) = myFileHead.fPaletteSize; /* read the palette */ if((*palette_size) > 0) { (*ppPalette) = (YUVQUAD *) malloc(sizeof(YUVQUAD) * (*palette_size)); if (_read(fd, (*ppPalette), sizeof(YUVQUAD) *(*palette_size)) != (int) (sizeof(YUVQUAD) * (*palette_size))) { _close(fd); return 0; } } /* read anchors along with other html nodes */ while (1) { if (_read(fd, &myInfoHead, sizeof(HTML_InfoHead)) != sizeof(HTML_InfoHead)) { break; } if (myInfoHead.hSize > 0) { pNodeInfo = (HTML_Info *) malloc(myInfoHead.hSize + sizeof(HTML_InfoHead)); if (!pNodeInfo) break; memcpy(pNodeInfo, &myInfoHead, sizeof(HTML_InfoHead)); if (_read(fd, &pNodeInfo[sizeof(HTML_InfoHead)], myInfoHead.hSize) != (int) myInfoHead.hSize) { break; } /* check if we need to do memory allocation */ if (total_nodes >= max_nodes) { if(!max_nodes) { /* no node in the list yet */ (*ppNodeList) = (HTML_Info **) malloc( sizeof (HTML_Info *) * BLOCK_SIZE); } else { (*ppNodeList) = (HTML_Info **) realloc((*ppNodeList), max_nodes + sizeof (HTML_Info *) * BLOCK_SIZE); } if(!(*ppNodeList)) break; max nodes += BLOCK_SIZE; } (*ppNodeList)[total_nodes] = pNodeInfo; total_nodes++; } } _close(fd); /* test our data */ for (i = 0; i < total_nodes; i++) { pNodeInfo = (*ppNodeList)[i]; pHead = (HTML_InfoHead *) pNodeInfo; pNodeData = pNodeInfo + sizeof(HTML_InfoHead); if(pHead−>hType == HTML_TYPE_TEXT) { HTML_Text *pText = (HTML_Text *) pNodeData; } else if (pHead−>hType == HTML_TYPE_IMAGE) { HTML_Image *pImage = (HTML_Image *) pNodeData; if (pImage−>fnameLen > 0) { /* load the image file */ pImage−>data = load_ybm (pImage−>fname); } } else if (pHead−>hType == HTML_TYPE_ANCHOR) { HTML_Anchor *pAnchor = (HTML_Anchor *) pNodeData; } else if (pHead−>hType == HTML_TYPE_ANIMATION) { HTML_Animation *pAnimation = (HTML_Animation *) pNodeData; } else if (pHead−>hType == HTML_TYPE_MAPAREA) { HTML_MapArea *pMapArea = (HTML_MapArea *) pNodeData; } else if (pHead−>hType == HTML_TYPE_LINE) { HTML_Line *pLine = (HTML_Line *) pNodeData; } else if (pHead−>hType == HTML_TYPE_SQUARE) { HTML_Square *pSquare = (HTML_Square *) pNodeData; } else if (pHead−>hType == HTML_TYPE_CIRCLE) { HTML_Circle *pCircle = (HTML_Circle *) pNodeData; } else if (pHead−>hType == HTML_TYPE_FILLEDSQUARE) { HTML_FilledSquare *pFilledSquare = (HTML_FilledSquare *) pNodeData; } else if (pHead−>hType == HTML_TYPE_FILLEDCIRCLE) { HTML_FilledCircle *pFilledCircle = (HTML_FilledCircle *) pNodeData; } else if (pHead−>hType == HTML_TYPE_TITLE) { HTML_Title *pTitle = (HTML_Title *) pNodeData; } } return total nodes; }
[0042] The compiled HTML file structure is set forth in FIG. 7 as described in Table 2. The file structure begins with a ten character string COMPHTML 900 . This string is followed by a HTML file header structure 901 . After the file header structure, a YUV color palette is set forth in the structure 902 this consists of an array of YUVQUAD values for the target device. After the palette array, a list 903 of HTML information structures follows. Usually the first HTML information structure 904 consists of a title. Next, a refresh element typically follows at point 905 . This is optional. Next in the line is a background color and background images if they are used in this image. After that, a list of display elements is provided in proper order. The anchor node for the HTML file is always in front of the nodes that it contains. An animation node is always right before the animation image frames start. The image area nodes usually appear at the head of the list.
[0043] The HTML file header structure includes a first value BgColor at point 906 followed by palette size parameters for the target device at point 907 . The YUVQUAD values in the color palette consist of a four word structure specifying the Y, U, and V values for the particular pixel at points 908 - 910 . The HTML information structures in the list 903 consist of a type field 911 , a size field 912 , and the information which supports the type at field 913 . The type structures can be a HTML_Title, HTML_Text, HTML_Chinese, HTML_Xxge, HTML_Square, HTML_FilledSquare, HTML_Circle, HTML_FilledCircle, HTML_Line, HTML_Author, HTML_Animation, . . . .
[0044] Functions that would enable a thin platform to support viewing of HTML-based content pre-compiled according to the present invention includes the following:
[0000] General Graphics Functions:
[0000]
int DrawPoint (int x, int y, COLOR color, MODE mode);
int DrawLine (int x1, int y1, int x2, int y2, COLOR color, MODE mode);
int DrawRectangle(int x1, int y1, int x2, int y2, COLOR color, MODE mode);
int FillRectangle(int x1, int y1, int x2, int y2, COLOR color, MODE mode);
int ClearScreen(COLOR color);
Color Palette:
int ChangeYUVColorPalette( );
Bitmap Function:
int BitBlt(int dst_x1, int dst_y1, int dst_x2, int dst_y2, unsigned char *bitmap, MODE mode);
String Drawing Functions:
int GetStringWidth(char *str, int len);
int GetStringHeight(char *str, int len);
int DrawStringOnScreen(int x, int y, char *str, int len, COLOR color, MODE mode);
Explanation:
All (x, y) coordinates are based on the screen resolution of the target display device (e.g. 320×240 pixels).
COLOR is specified as an index to a palette.
MODE defines how new pixels replace currently displayed pixels (COPY, XOR, OR, AND).
Minimum support for DrawLine is a horizontal or vertical straight line, although it would be nice to have support for diagonal lines.
The ChangeYUVColorPalette function is used for every page.
BitBlt uses (x1, y1) and (x2, y2) for scaling but it is not a requirement to have this scaling functionality.
String functions are used for English text output only.
[0062] Bitmaps are used for Chinese characters.
[0063] FIGS. 8A and 8B set forth the run time engine suitable for execution on a thin client platform for display of the compiled HTML material which includes the function outlined above in the “display” step 1220 of FIG. 8B .
[0064] The process of FIG. 8A starts at block 1000 . The run time engine is initialized on the client platform by loading the appropriate elements of the run time engine and other processes known in the art (step 1010 ). The next step involves identifying the position of the file, such as on the source CD or other location from which the file is to be retrieved and setting a flag (step 1020 ). The flag is tested at step 1030 . If the flag is not set, then the algorithm branches to block 1040 at which the flag is tested to determine whether it is −1 or not. If the flag is −1, then the algorithm determines that a system error has occurred (step 1050 ) and the process ends at step 1060 . If the flag at step 1040 is not −1, then the file has not been found (step 1070 ). Thus after step 1070 the algorithm returns to step 1020 to find the next file or retry.
[0065] If at step 1030 , the flag is set to 1 indicating that the file was found, then the content of the file is retrieved using a program like that in Table 3, and it is stored at a specified address. A flag is returned if this process succeeds set equal to 1 otherwise it is set equal to 0 (step 1080 ). Next the flag is tested (step 1090 ). If the flag is not equal to 1 then reading of the file failed (step 1100 ). The process then returns to step 1020 to find the next file or retry.
[0066] If the flag is set to 1, indicating that the file has been successfully loaded into the dynamic RAM of the target device, then the “Surf_HTML” process is executed (step 1110 ). The details of this process are illustrated in FIG. 8B . Next the current page URL name is updated according to the HTML process (step 1120 ). After updating the current URL name, the process returns to step 1020 to find the next file.
[0067] FIG. 8B illustrates the “Surf_HTML” process of step 1110 in FIG. 8A . This process starts at point 1200 . The first part is initialization step 1210 . A display routine is executed at step 1220 having the fixed coordinate functions of the precompiled HTML data set. First, the process determines whether applets are included in the file (step 1230 ). If they are included, then the applet is executed (step 1239 ). If no applets are included or after execution of the applet, then a refresh flag is tested (step 1240 ). If the flag is equal to 1, then it is tested whether a timeout has occurred (step 1250 ). If a timeout has occurred, then the current page is updated (step 1260 ) and the process returns set 1210 of FIG. 8B , for example.
[0068] If at block 1240 the refresh flag was not equal to 1, or at block 1250 the timeout had not expired, then the process proceeds to step 1270 to get a user supplied input code such as an infrared input signal provided by a remote control at the target device code. In response to the code, a variety of process are executed as suits a particular target platform to handle the user inputs (step 1280 ). The process returns a GO_HOME, or a PLAY_URL command, for example, which result in returning the user to a home web page or to a current URL, respectively. Alternatively the process loops to step 1270 for a next input code.
[0069] As mentioned above, FIG. 4 illustrates the JAVA precompiler according to the present invention. The JAVA precompiler receives standard full feature JAVA byte codes as input on line 600 . Byte codes are parsed at block 601 . A JAVA class loader is then executed at block 602 . The classes are loaded into a command module 603 which coordinates operations of a JAVA virtual machine 604 , a JAVA garbage collection module 605 , and a JAVA objects memory mapping optimizing engine 606 . The output is applied by block 607 which consists of a compiled JAVA bytecode format according to the present invention.
[0070] The process is illustrated in FIG. 9 beginning at block 1500 . First the JAVA bytecode file is loaded (block 1510 ). Next, the JAVA classes are loaded based on the interpretation of the bytecode (step 1520 ). Next the classes are optimized at step 1530 . After optimizing the classes, the byte codes are translated to a reduced bytecode (step 1540 ). Finally the reduced bytecode is supplied (step 1550 ) and the algorithm stops at step 1560 . Basically the process receives a JAVA source code file which usually has the format of a text file with the extension JAVA. The JAVA compiler includes a JAVA virtual machine plus compiler classes such as SUN.TOOLS.JAVAC which are commercially available from Sun Micro Systems. The JAVA class file is parsed which typically consists of byte codes with the extension CLASS. A class loader consists of a parser and bytecode verifier and processes other class files. The class structures are processed according to the JAVA virtual machine specification, such as the constant pool, the method tables, and the like. An interpreter and compiler are then executed. The JAVA virtual machine executes byte codes in methods and outputs compiled JAVA class files starting with “Main”. The process of loading and verifying classes involves first finding a class. If the class is already loaded a read pointer to the class is returned, if not, the class is found from the user specified class path or directory, in this case a flash memory chunk. After finding the class, the next step is executed. This involves loading the bytes from the class file. Next, class file bytes are put into a class structure suitable for run time use, as defined by the JAVA virtual machine specification. The process recursively loads and links the class to its super classes. Various checks and initializations are executed to verify and prepare the routine for execution. Next, initialization is executed for the method of the class. First the process ensures that all the super classes are initialized, and then cause the initialization method for the class. Finally, the class is resolved by resolving a constant pool entry the first time it is encountered. A method is executed with the interpreter and compiler by finding the method. The method may be in the current class, its super class or other classes as specified. A frame is created for the method, including a stack, local variables and a program counter. The process starts executing the bytecode instructions. The instructions can be stack operations, branch statements, loading/storing values, from/to the local variables or constant pool items, or invoking other methods. When an invoked method is a native function, the implemented platform dependent function is executed.
[0071] In FIG. 9A , the process of translating JAVA byte codes into compiled byte codes (step 1504 of FIG. 9 ) is illustrated. According to the process FIG. 9A , the high level class byte codes are parsed from the sequence. For example, Windows dialog functions are found ( 1570 ). The high level class is replaced with its lower level classes ( 1580 ). This process is repeated until all the classes in the file become basic classes ( 1590 ). After this process, all the high level functions have been replaced by lower level level basic functions, such as draw a line, etc. ( 1600 ).
[0072] JAVA byte codes in classes include a number of high level object specifying functions such as a window drawing function and other tool sets. According to the present invention, these classes are rendered by the precompiler into a set of specific coordinate functions such as those outlined above in connection with the HTML precompiler. By precompiling the object specifying functions of the JAVA byte code data set, significant processing resources are freed up on the thin client platform for executing the other programs carried in a JAVA byte code file. Furthermore, the amount of memory required to store the run time engine and JAVA class file for the thin client platform according to the present invention which is suitable for running a JAVA byte code file is substantially reduced.
[0073] FIG. 10 illustrates one environment in which use of the present invention is advantageous. In particular, in the Internet environment a wide variety of platforms are implemented. For example, an end user workstation platform 100 is coupled to the Internet 101 . An Internet server platform 102 is also coupled to the Internet 101 and includes storage for JAVA data sets, HTML data sets, and other image files. A server 103 with an intermediate compiler according to the present invention for one or more of the data sets available in the Internet is coupled to the Internet 101 as well. A variety of “thin” platforms are also coupled to the Internet and/or the server 103 . For example, an end user thin platform A 104 is coupled to the server 103 . End user thin platform B 105 is coupled to the server 103 and to the Internet 101 . End user thin platform C 106 is coupled to the Internet 101 and via the Internet all the other platforms in the network. A variety of scenarios are thus instituted. The source of data sets for end user platform C 106 consists of the World Wide Web. When it requests a file from server 102 , the file is first transferred to the intermediate compiler at server 103 , and from server 103 to the end user platform 106 . End user platform A 104 is coupled directly to the server 103 . When it makes a request for a file, the request is transmitted to the server 103 , which retrieves the file from its source at server 102 , translates it to the compiled version and sends it to platform A 104 . End user platform B is coupled to both the server 103 and to the Internet 101 . Thus, it is capable of requesting files directly from server 102 . The server 102 transmits the file to server 103 from which the translated compiled version is sent to platform B 105 . Alternatively, platform B may request a file directly from server 103 which performs all retrieval and processing functions on behalf of platform B.
[0074] FIG. 11 illustrates an alternative environment for the present invention. For example, the Internet 120 and an Intranet 121 are connected together. A server 122 is coupled to the Intranet 121 and the Internet 120 . The server 122 includes the HTML and JAVA intermediate compiling engines according to the present invention as represented by block 123 . The server 122 acts as a source of precompiled data sets for thin client platforms 124 , 125 and 126 each of which has a simplified run time engine suitable for the compiled data sets. Thus the powerful HTML/JAVA engine resides on the network server 122 . The thin network computers 124 , 125 , 126 are connected to the server have only the simplified run time engine for the compiled image set. Thus, very small computing power is required for executing the display. Thus computing tasks are done using the network server, but displayed on a thin network computer terminals 124 - 126 .
[0075] FIGS. 12A and 12B illustrate the off-line environment for use of the present invention. In FIG. 12A , the production of the compiled files is illustrated. Thus, a standard object file, such as an HTML or JAVA image, is input online 1300 to a compiler 1301 which runs on a standard computer 1302 . The output of the compiler on line 1303 is the compiled bitmap, compiled HTML or compiled JAVA formatted file. This file is then saved on a non-volatile storage medium such as a compact disk, video compact disk or other storage medium represented by the disk 1304 .
[0076] FIG. 12B illustrates the reading of the data from the disk 1304 and a thin client such as a VCD box, a DVD box or a set top box 1305 . The run time engine 1306 for the compiled data is provided on the thin platform 1305 .
[0077] Thus, off-line full feature HTML and JAVA processing is provided for a run time environment on a very thin client such as a VCD/DVD player. The standard HTML/JAVA objects are pre-processed and compiled into the compiled format using the compiler engine 1301 on a more powerful computer 1302 . The compiled files are saved on a storage medium such as a floppy disk, hard drive, a CD-ROM, a VCD, or a DVD disk. A small compiled run time engine is embedded or loaded into the thin client device. The run time engine is used to play the compiled files. This enables use of a very small client for running full feature HTML and JAVA programs. Thus, the machine can be used in both online, and off-line modes, or in a hybrid mode.
[0078] The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. It is intended that the scope of the invention be defined by the following claims and their equivalents.
[0079] What is claimed is:
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A system for processing an object specified by an object specifying language such as HTML, JAVA or other languages relying on relative positioning, that require a rendering program utilizing a minimum set of resources, translates the code for use in a target device that has limited processing resources unsuited for storage and execution of the HTML rendering program, JAVA virtual machine, or other rendering engine for the standard. Data concerning such an object is generated by a process that includes first receiving a data set specifying the object according to the object specifying language, translating the first data set into a second data set in an intermediate object language adapted for a second rendering program suitable for rendering by the target device that utilizes actual target display coordinates. The second data set is stored in a machine readable storage device, for later retrieval and execution by the thin client platform.
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BACKGROUND OF THE INVENTION
The invention relates to an apparatus for feeding blanks to a packaging machine, especially for the production of hinge-lid (cigarette) packs, the blanks produced elsewhere being fed as a blank stack to a blank magazine located at the machine, and individual blanks for producing the packs being extracted from this.
On packaging machines with a high production capacity, especially on cigarette-packaging machines, the sufficient availability of blanks presents a particular problem. When packs are made of relatively thick packaging material (cardboard), it is often customary to manufacture individual blanks separately from the packaging material and feed blank stacks to the packaging machine. It is particularly important, here, that a sufficient stock of blanks should be formed in the region of the packaging machine and supplemented to the necessary degree.
SUMMARY OF THE INVENTION
The object on which the invention is based is to provide an apparatus for driving a stock of blanks to be fabricated elsewhere and carry them to a packaging machine; the blanks are transferred automatically, as required, from a larger stock of blanks for a blank magazine belonging to the packaging machine.
To achieve this object, the apparatus according to the invention is characterized in that, at any particular time, several blank stacks can be advanced to the packaging machine on a transportable stack carrier (stack pallet) and can be successively extracted from the stack carrier and fed to the blank magazine by means of a stack conveyor.
Stack carriers (stack pallets) with a large capacity are loaded at a suitable central point with blank stacks which are arranged in closely packed rows on the stack carrier. The stack carriers are movable, in particular by means of rollers on rails, and can thus be advanced to the respective packaging machine.
The stack carriers assume a predetermined exact (variable) relative position in relation to the packaging machine, in such a way that blank stacks can be removed in succession from the stack carrier, as required, by the stack conveyor and conveyed to the blank magazine located at the machine. The stack carrier is preferably arranged at the rear of the packaging machine. The stack conveyor transports the blank stacks to the front of the packaging machine, where the blank magazine is arranged in an upper region. Accordingly, the stack conveyor consists of an elevator located at the rear of the packaging machine, a cross-conveyor following this above the packaging machine, and a lowering conveyor leading to the blank magazine.
The elevator is equipped with a stack pick-up for each blank stack, preferably an upper and a lower clamping jaw movable relative to one another. A particular blank stack is grasped between the clamping jaws and conveyed upwards.
The stack carriers are designed in a special way. In the region of a supporting base, there are lateral (along the longitudinal edge) recesses, through which the lower clamping jaw of the elevator can pass in order to pick up or take up the stack. A recess of this type is assigned to each row of the blank stacks. As a result of a shift of the (part) rows on the stack pallet or as a result of the movement of the latter, the blank stacks are brought successively into the pick-up position for the stack conveyor.
The apparatus according to the invention is also designed for two-track operation of the packaging machine. In this case, according to a proposal of the invention, there is a branch in the region of the stack conveyor, preferably at the transfer from the elevator to two crossconveyors running next to one another.
Alternatively, in order to increase the output, two stack carriers (stack pallets) can be advanced to the packaging machine, a separate stack conveyor being assigned to each stack pallet.
Further features of the invention relate to the design of the stack carriers (stack pallets) and to the conveyors for transporting the blank stacks.
Exemplary embodiments of the invention are explained in detail below with reference to the drawings.
In these:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a diagrammatic side view of the apparatus for storing blank stacks and transferring them to a packaging machine,
FIG. 2 shows a transverse view of the apparatus according to FIG. 1, with parts of the packaging machine omitted,
FIG. 2a shows a detail of the apparatus in a view offset 90° relative to FIG. 2,
FIG. 3 shows a plan view of the apparatus in a lower plane (above a stack carrier),
FIG. 4 shows a plan view in an upper plane (in the region of cross-conveyors),
FIG. 5 shows a cross-conveyor as a detail in horizontal projection, on an enlarged scale (sectional plane V--V in FIG. 1),
FIG. 6 shows a plan view of a stack carrier (pallet) in the loaded state,
FIG. 7 shows a representation similar to that of FIG. 6, after the preparation of a first row of blank stacks for take-over by a stack conveyor,
FIG. 8 shows a representation of the stack carrier according to FIG. 6 and 7 after the discharge of several blank stacks,
FIG. 9 shows a side view of a stack carrier (stack pallet),
FIG. 10 shows a cross-section through a stack pallet in the sectional plane X--X of FIG. 8,
FIG. 11 shows a representation similar to that of FIG. 2 for a version of the apparatus with two stack carriers and separate stack conveyors,
FIG. 11a shows a detail of the exemplary embodiment according to FIG. 11 in a view offset 90°,
FIG. 12 shows a plan view of the apparatus according to FIG. 11,
FIG. 13 shows a plan view of the apparatus according to FIGS. 11 and 12 in an upper plane (crossconveyor).
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The exemplary embodiments illustrated relate to the feeding of a packaging machine 20 for cigarettes with blanks 21. The blanks 21 made elsewhere by being punched from cardboard-like packaging material serve for producing hinge-lid packs. The conventionally shaped blanks 21 are combined into blank stacks 22 consisting of a relatively large number of blanks 21. These blank stacks 22 are conveyed in succession to a blank magazine 23 belonging to the packaging machine 20. The individual blanks 20 are extracted from the blank magazine 23 on the underside and introduced into the packaging process. In the present case, a rolling-off device 24 of known design is provided for extracting the blanks 21.
The principal component of the apparatus for feeding the packaging machine 20 with blanks 21 is a stack carrier, here designed as a stack pallet 25. The blank stacks are stored on this, namely on a base plate 26, until they are taken off by a stack carrier 27.
The stack pallets 25 are loaded at a central point and fed to the packaging machine 20, in the present case at the rear of this, so that access to the front of the packaging machine 20 is not impeded. The stack pallet 25 is movable by means of wheels 28, in the present case on running rails 29 attached to the floor.
The stack pallet 25, rectangular as seen in horizontal projection, is equipped at the rear with a supporting wall 30, approximately at the height of the blank stack 22. On the remaining sides, a rim 31 of less overall height is provided all around, in order to secure the blank stacks 22 on the base plate 26. In the present exemplary embodiment, the dimensions of this are such that 28 blank stacks 22 are accommodated. Each blank stack 22 has a height of approx. 450 mm. This results in a load of the stack pallets 25 corresponding to approximately 1 hour's requirement of blanks for the packaging machine 20 at a machine output of 700 packs per minute.
The blank stacks 22 are arranged on the base plate 26 in transverse stack rows 32, 33 placed close to one another. The blanks 21 have their longitudinal extension directed transversely relative to the stack rows 32, 33. The blank stacks 22 are lifted off in succession from the stack pallets 25 in the region of a discharge station 34 by the stack conveyor 27. This is located in the region of the discharge station 34. The stack pallets 25 are so positioned and movable relative to the discharge station 34 that the blank stacks 22 can each be received along a longitudinal edge of the stack pallet 25.
For this purpose, the stack pallet 25 on its base plate 26 is provided laterally, in particular along one longitudinal side, with recesses 35 which, in the present exemplary embodiment, are T-shaped as seen in horizontal projection. The recesses 35 are open towards the sides. In the region of the recesses 35, the stack pick-up of the stack conveyor 27 can grasp the blank stack 22 from below and carry it in the upward direction. In the present exemplary embodiment, the pick-up for a blank stack 22 consists of two (upper and lower) clamping jaws 36 and 37, between which a particular blank stack 22 is received. Clamping jaws 36, 37 are movable away from one another and together in order to grasp and release the blank stack 22. In the present case, the lower clamping jaw 36 passes from below through the particular recess 35 of the base plate 26 located at the discharge station 34 and thus discharges the blank stack 22 resting in the region of this recess 35.
The blank stacks 22 on the stack pallets 25 are moved successively into the region of the discharge station 34. For this purpose, at least the particular stack row 33 to be discharged is released from the remaining stack rows 32 on the stack pallet 25, so that the blank stacks 22 of this are free. To this effect, the blank stack 22 located in the discharge station 34 and positioned at the edge of the respective stack row 33 is retained between the clamping jaws 36, 37. On the opposite side of the stack rows 33, a transverse slide 38 is activated. This comes up against the outer face of the outer blank stack 22 of this stack row 33. As a result of transverse pressure exerted by the transverse slide 38, the complete stack row 33 is compressed and thus fixed as a single unit. The stack pallet 25 can now be moved back a little way, in the present case from the position according to FIG. 6 into the position according to FIG. 7. As a result, because of the clearance on the base plate 26 the (front) stack row 33 is released from the following one, thereby forming a transverse gap 39. At the same time, the likewise T-shaped clamping jaws or the lower clamping jaw 36 is shifted relatively in the recess 35 of the discharge station 34, in particular likewise from the position according to FIG. 6 into that according to FIG. 7. The recesses 35 have appropriately large dimensions. After a slight retraction of the transverse slide 38 and consequently the removal of the transverse pressure, the first blank stack 22 located at the edge of this stack row 33 can now be conveyed upwards.
In order to discharge the further blank stacks 22 of this (front) stack row 33, the remaining blank stacks 22 of the latter are shifted successively in the direction of the discharge station 34 by the transverse slide 38 (see FIG. 8). When this stack row 33 has been removed completely, the same procedure is adopted for the next one, the stack pallet 25 first being moved further a stroke corresponding to a stack row 32.
By means of appropriate devices the stack pallet 25 can be advanced (automatically) to the packaging machine 20 and moved to and fro in the region of the latter to the extent described. For this purpose, a clip 40 for fastening a drive member is attached to the rear side of the stack pallet 25 or to its supporting wall 30.
In the present case, the angular transverse slide 38 is displacable by means of a spindle mechanism. Part of the transverse slide 38 is mounted as a spindle nut 43 on an elongate spindle 42 mounted fixedly on a gear casing 41. The spindle 42 is driven to rotate by means of a motor 44.
In the exemplary embodiments illustrated, the stack conveyor 27 consists of several individual conveyors adjoining one another. An elevator 45 is arranged in the region of the discharge station 34. In a region above the packaging machine 20, in particular in a transfer station 46, there follows a cross-conveyor 47 which leads transversely over the packaging machine 20 to the front of the latter. The blank stacks 22 are transferred from this cross-conveyor 47 to a lowering conveyor 48. This is followed to the bottom by the blank magazine 23.
The elevator 45 can be designed in various ways. In the present exemplary embodiment, it is a spindle conveyor with a fixed vertical spindle 49. This is mounted rotatably in a floor bearing 50 and likewise rotatably in an upper supporting bearing 51 which is connected in a suitable way to the structure of the packaging machine 20. The rotary drive of the spindle 49 is effected in the region of the upper supporting bearing 51 by means of a servo-motor 52 with a pinion 53 via a gear wheel 54.
The lower clamping jaw 36 is mounted on the spindle 49 by means of an elongate spindle nut 74. When the spindle 49 rotates, the lower clamping jaw 36 is thus moved up and down. The upper clamping jaw 37 is likewise mounted slideably on the spindle 49 by means of a guide sleeve 55, but without engagement with the thread of the spindle 49. In this way, this upper clamping jaw 37 can also be moved upwards by means of or together with the spindle nut 74. The spindle nut 74 and the guide sleeve 55 are designed with telescopic ends 56. These overlap one another when the clamping jaws 36 and 37 are in the clamping position. The manner in which these are actuated is not shown for the sake of this simplified representation. For example, the upper clamping jaw 37 can be moved relative to the lower clamping jaw 36 by means of a pressure-medium cylinder, and the clamping force can be transmitted in this way.
In the region of the transfer station 46, the upper clamping jaw is released in an upper end position after reaching the lower clamping jaw. The blank stack 22 can now be pushed off the lower clamping jaw 36 in transverse direction by means of a pushing-off device 57. On the upper side located opposite the platform 58, the blank stack 22 is fixed by a cover plate 59.
After the platform 58, the blank stacks 22 pass between upper and lower central conveyor belts 60 and 61. The blank stacks 22 are transported in the region of the platform 58 by means of the pushing-off device 57. The conveyor belts 60 and 61 are driven, so that the blank stacks 22 are transported in the direction of the arrow.
A transfer member for the blank stacks 22 is located at the end of the cross-conveyor 47 and of the conveyor belts 60, 61. Two supporting arms 63 and 64 are mounted pivotably on a transversely directed supporting rod 62 (FIG. 2a). These are equipped, at the lower ends, with transversely directed supporting legs 65, on which a blank stack 22 is received when it leaves the conveyor belts 60, 61. For this purpose, the supporting arms 63, 64 are moved away from one another on the supporting rod 62 by means of a suitable drive member (for example a pressure-medium cylinder), so that the blank stack 22 can be conveyed into the region between the supporting arms 63, 64. When the supporting arms 63, 64 are brought together into the position according to FIG. 2a, the blank stack 22 is consequently grasped, and at the bottom it rests on the supporting legs 65 angled inwards and forwards. Owing to the shape of the supporting arms 63, 64 (angular cross-section), the blank stack 22 is grasped laterally and also at the rear over its entire height.
As a result of a pivoting movement of the supporting arms 63, 64, the blank stack 22 is brought into an inclined position (FIG. 1). A lowering conveyor 48 can now receive the blank stack and feed it to the blank magazine 23. In the present case, the lowering conveyor 48 is designed as a supporting web 66 movable up and down also upwards and backwards. This is moved under the blank stack 22 held by the supporting arms 63, 64 (FIG. 1). After the supporting arms 63, 64 have been moved away from one another, the blank stack 22 is fed to the blank magazine 23 as a result of a downward movement of the supporting web 66. The supporting web 66 is then retracted, moved into the upper position and brought under the next blank stack 22. The design and drive of the supporting web 66 correspond essentially to those of the member used for the same purpose in the subject of patent application DE-A-3,402,514.
The productivity of the apparatus can be increased as shown in the exemplary embodiment of FIG. 4 by blank stacks 22 being conveyed into two tracks in the region of the cross-conveyor 47 and thereafter. For this purpose, the first cross-conveyor 47 of the design described is arranged after the transfer station 46. The connecting platform 67 leads transversely from this to a second crossconveyor 68. This is of a design identical or similar to that of the cross-conveyor 47 described. The blank stacks 22 delivered by the elevator 45 are fed alternately to the cross-conveyor 47 and the cross-conveyor 68. The transverse movement to the latter is executed by means of a slide 69 which conveys blank stacks 22 via the connecting platform 67 to the cross-conveyor 68 from the free side in the region of the platform 58. A pushing-off device 70 corresponding to the pushing-off device 57 is assigned to the cross-conveyor 68. The further conveyor members, in particular the lowering conveyor 48, and the blank magazine 23 are likewise duplicated.
FIGS. 11 to 13 show details of an apparatus, in which a first stack pallet 25 with blank stacks 22 is advanced to the packaging machine 20 (to its rear) in the way described, and a further second stack pallet 71. This stack pallet 71 is of the same design as the stack pallet 25 described. Furthermore, this second stack pallet 71 is assigned a separate elevator 72 which is of the same design as the elevator 45 already described. The arrangement is such that the clamping jaws 36, 37, each movable on a spindle nut 74 and belonging to the two elevators 45 and 72 are directed away from one another, so that the stack pallets 25 and 71 can be advanced from opposite sides to the elevators 45 and 72 arranged immediately adjacent to one another. The spindles 49 of these are arranged at a slight distance from one another and are supported rotatably on a common floor bearing 73.
Each of the elevators 45, 72 conveys the blank stacks 22 to a cross-conveyor and to a lowering conveyor in the way described. Accordingly, two separate stack conveyors are used here, and these can be operated independently of one another.
Details of the apparatus can be designed differently from those of exemplary embodiments illustrated. Thus, the pack pallets 25 can have assigned to them an upper cover plate which, in the region of the discharge station 34, has a suitable recess for the passage of a particular blank stack 22. The cover plate keeps the remaining or neighbouring blank stacks 22 from being lifted together with it.
The apparatus described can be used to particular advantage in conjunction with a packaging machine for hingelid packs according to German Patent P 24 40 006. This packaging machine is equipped with a folding turret 75 which is rotatable about a vertical axis and which is illustrated diagrammatically in the drawings. The blank magazine 23 or the blank magazines are arranged above the folding turret 75, so that the blanks can be fed to the folding turret 75 in the way described in Patent P 24 40 006.
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For supplying a sufficient quantity of prefabricated blanks (21) to packaging machines (20), blank stacks (22) are brought up to the packaging machine (20) on a stack pallet (25). By the use of at least one stack conveyor (27), the blank stacks (22) are taken off from the stack pallet (25) in succession and conveyed to a blank magazine (23) of the packaging machine (20).
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BACKGROUND OF THE INVENTION
This invention relates generally to banding articles and particularly to a novel band for applying implosion protection to a cathode ray tube (CRT).
There are varied instances in the art where there is a need for a tensioned band about an article. In many instances the band must be accurately tensioned with a predetermined tension. An example of a case where a band must be applied to an article with a known tension is that of implosion protecting a CRT. A CRT includes a large evacuated glass envelope. Because the envelope is evacuated, atmospheric pressure tends to collapse, or implode, the tube resulting in a potentially hazardous condition. It has been learned that the hazard of implosion can be greatly reduced by applying a tensioned band around the envelope in the stress area which exists on the sidewall between the faceplate and the frit seal where the faceplate panel and the envelope funnel are joined.
In one method of applying a band to a CRT, the free end of the band is passed completely around the sidewall to form a loop about the sidewall. The free end of the band is overlapped by the looped band and thus lies between the looped band and the sidewall. The free end is firmly grasped by a holding device and a tensioning device pulls the other end of the band to tension the looped band around the article. After the desired tension is reached, the overlapped portion between the two ends is crimped to permanently retain the tension in the looped band. A problem frequently arises in the implosion proofing of a CRT because the free end of the band must be firmly grasped while the tensioning force is being applied. Accordingly, the holding device typically is heavy and quite bulky. Accommodation of the bulky holding device, necessitates the displacement of the band from the CRT sidewall. As a result, when the holding device is removed, the band closes against the sidewall resulting in a substantial relaxation of the band tension.
The instant invention is directed toward a novel band configuration which prevents the tensioned band from moving against the CRT sidewall when the holding device is removed.
The instant invention can be made using the invention described in Application Ser. No. 200,538 filed of even date herewith by Laurence B. Kimbrough and entitled "Holding and Notching Tool for CRT Implosion Protection" now U.S. Pat. No. 4,356,845.
SUMMARY OF THE INVENTION
A tensioning band is looped about an article to be tensioned. A first end of the band is overlapped by the looped band to lie between the looped band and the article. A second end of the band lies outside the loop to form the overlapped portion between the two ends. The overlapped portion is permanently crimped together. The first end includes notches on both edges to form tabs which extend away from the plane of the end to keep the looped band spaced from the article in the vicinity of the first end.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view, partially broken away, showing an implosion protection band looped around a CRT.
FIG. 2 is a top view, partially broken away, showing an implosion protection band looped around a CRT.
FIG. 3 is a preferred embodiment of the instant invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIGS. 1 and 2, an implosion protection band 10 is looped around a CRT along the stress area on the faceplate panel sidewall between a faceplate panel 16 and a frit seal 17 where the faceplate panel 16 is joined to a funnel portion 18 of the CRT envelope. The band 10 is connected to a supply of banding material (not shown) by a broken off end 11. A free end 12 of the band is arranged between the looped band and the CRT resulting in an overlapped portion 13 between the two ends 11 and 12. A clip 14 is placed over the overlapped portion 13 and a crimping device of known type crimps the clip and overlapped portion together.
During tensioning the free end 12 is firmly grasped by a holding device and a tensioning device pulls the end 11 of the looped band 10 to tension the band tightly around the CRT. The holding device preferably is of the type described in the previously referenced U.S. Pat. No. 4,356,845. The holding device must resist the pulling force of the tensioning device to avoid relative movement between the free end 12 and the CRT and thus must be quite bulky. Accommodation of the holding device between the looped band and the free end 12, therefore, requires the looped band to be displaced from the CRT. As a result, when the holding device is removed the band closes against the CRT resulting in a substantial relaxation of the tension in the band. The instant invention overcomes this difficulty by prohibiting the looped band from moving into contact with the CRT and thus substantially reduces the tension relaxation.
As shown in FIG. 3, the free end 12 of the band 10 has a plurality of notches 19a along one edge and a plurality of similar notches 19b along the other edge. The notches 19a and 19b along the two edges preferably are transversely aligned across the width of the end 12. During the formation of the notches 19a and 19b, the metal is not removed but rather is bent over to form a plurality of tabs 20a and 20b spaced along the two edges of the free end 12.
The number of notches, and thus also the number of tabs, is a function of the desired tension to be applied to the band 10. Accordingly, as the desired tension increases the number of notches also can be increased since the sides of the notches resist the pulling force. The depth of the notches also is a function of the desired tension because the sides of the notches resist the pulling force. Accordingly, the notch depth also can be increased as the desired tension increases. However, the portion of the band remaining between the notches must be sufficiently strong to withstand the pulling force of the tensioning device. Accordingly, the notches 20a and 20b each have a depth which preferably is about 6% to 8% of the transverse width of the band. The tabs 20a and 20b are formed to extend away from the CRT toward the looped band 10. Accordingly, as more clearly shown in FIG. 2, space is provided to accommodate a holding device between the looped band 10 and the CRT sidewall. However, when the holding device is removed, the looped band 10 cannot move against the CRT because the tabs 20a and 20b inhibit such movement.
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A tensioning band includes a plurality of notches in the free end. Formed in the notches are tabs which extend between the free end and the tensioned loop to prevent the loop from moving against the article being tensioned and thereby relaxing the tension.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Application is a completion application based on co-pending United States Provisional Application Ser. No. 06/196,723, filed Apr. 13, 2000, having the title “Animal Trap”, the disclosure of which is hereby specifically incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates, in general, to improvements in traps for small animals in the form of a cage structure for trapping and holding, without harming, the animal whereby the animal can be relocated to another area. More particularly, the invention relates to spring and gravity actuated closure arrangements for use in such cage structures.
[0004] 2. Description of Prior Art
[0005] Animal traps comprising a cage of metal mesh and constructed with locking means for locking a trap door in a closed position are known. The animal trap typically includes a tripping mechanism that is tripped when the animal is lured into the cage to obtain bait placed therein and operates to cause the trap door to move between an open position and into a closed position. A locking mechanism cooperates to releasably lock the trap door in the closed position.
[0006] In some animal traps, the trap door falls by gravity and into engagement with a lock member to ensure that the door does not open and allow the trapped animal to escape. These traps are simple in operation and construction.
[0007] However, since animal traps are typically placed outside and are subject to the environment, they can rust or otherwise be subject to mud or other material. A trap door that relies solely on gravity to move into its closed position might have to rely on its ability to overcome the problems associated with its prolonged exposure to the environment and may not close at all or only partially, thereby permitting the animal to escape from the cage.
[0008] To overcome certain problems associated with the environment, some animal traps have arranged springs and linkage rods together with one another and with the trap door whereby to positively bias the trap door into the closed position or a latch member into a locked relation with the trap door. Depending on the spring and trap door arrangement, a biased trap door could close about and harm the animal.
[0009] There is always a need for improvement in animal traps that enable a small animal to be trapped without harm.
[0010] An object of this invention is the provision of an animal trap that enables small animals to be safely trapped in a cage for relocation to another place.
[0011] Another object of this invention is an animal trap having an improved closure, tripping and locking means for containing an animal that enters the trap.
[0012] Still another object of this invention is the provision of an animal trap for small animals, the trap including a simple yet effective tripping mechanism that is actuated by the animal entering the trap.
SUMMARY OF THE INVENTION
[0013] According to a first embodiment of this invention there is provided an animal trap including a tripping mechanism operably connected to a spring-loaded closure structure that cooperates with a trap door to provide positive and rapid snap closure of the trap door without harming the animal. In particular, the animal trap comprises:
[0014] a cage having a top, a bottom, a back, and side walls of mesh or like material, the side walls joining the top, bottom, and back walls whereby to form an enclosure having a front opening enterable by an animal,
[0015] a trap door having a top edge portion hingedly affixed to the top of the cage and a bottom edge portion, said trap door being rotatable between a raised cage open position permitting entry into the cage and into a lowered cage closed position wherein the trap door is in covering relation with the front opening, this door being sized substantially equal to the size of the first opening;
[0016] a trip lever hingedly affixed to the cage and disposed within the enclosure, the trip lever being tripped by an animal trying to get to bait in the back of the cage;
[0017] a trip rod rotatably mounted to said cage and including a catch member for engaging and maintaining the trap door in the raised cage open position,
[0018] a linkage structure connecting the trip rod to the trip lever, and
[0019] a spring operated locking structure for biasing the trap door from said raised position and toward said lowered position and releasably maintaining the trap door in the lowered cage closed position,
[0020] whereby movement of the trip lever is transmitted by the linkage structure to the trip rod causing the trip rod to rotate and the catch member to be dislodged from its engagement with the trap door whereupon gravity and the spring operated locking structure act to drive the trap door into closing relation with the front opening.
[0021] The spring operated locking structure comprises a brace member having a first end portion hingedly connected to the trap door proximate to the bottom edge portion thereof and a second end portion, a spring member connecting the bottom edge portion of the trap door to the brace member, and a catch member proximate to the top of the cage for engaging the second end portion of the brace member. In the lowered cage closed position, the free end of the brace member positions the hinged end thereof so as to drive the bottom edge portion of the trap door downwardly and into the cage closed position.
[0022] Preferably, the cage includes a front wall of mesh or like material and is provided with a central opening for the animal to enter, the front wall being adapted to be covered by the trap door when in the lowered cage closed position. Preferably, the front wall is disposed at an acute angle to the bottom wall, generally between about 40°-60° thereto. In a particular embodiment, the front wall is at about 45° to the bottom wall and forms the hypotenuse of a 45° right triangle.
[0023] In the raised cage open position, the brace member is folded onto the trap door and disposed between the trap door and the top wall of the cage. The second end of the brace member abuts the top wall and cooperates with the spring member (and gravity) to force the brace member and trap door downwardly and away from the top wall of the cage. Substantially simultaneously with release of the trap door, the force of gravity pulls the trap door downwardly, and the spring pulls the brace member away from its overlapped relation with the trap door. The spring forces the free end of the brace member against the top wall of the cage and into engagement with the catch member, the free end acting to drive the trap door (to which the hinged end of the brace member is connected) downwardly.
[0024] In the lowered cage closed position, the brace member and the trap door are at an acute angle to one another. The brace member has its second end portion positioned against the top wall and its first edge portion forcing the trap door into the closed position.
[0025] According to a second embodiment of this invention there is provided an animal trap including tripping and locking mechanisms operably connected to a closure structure that includes a trap door which operates under gravity to move between a raised position (generally parallel to the top wall of the cage) and to a lowered position (generally vertically extending between the top and bottom walls) to provide positive and rapid closure of the trap door without harming the animal. Similar to the first embodiment, the animal trap of this embodiment comprises a generally rectangularly configured cage comprised of walls of mesh-like construction or material otherwise apertured and having a front opening by which an animal can enter the cage to get to bait in the back of the enclosure.
[0026] More particularly, the animal trap of this embodiment comprises:
[0027] a pair of laterally spaced parallel guide posts, the posts extending vertically between the top and bottom walls proximate to the open front of the cage,
[0028] a trap door hingedly affixed to the top of the cage at the front thereof and movable between raised and lowered positions, the trap door having a bottom edge adapted to be proximate to the top and bottom walls, respectively, when the trap door is in the raised and lowered positions, respectively,
[0029] a guide collar connected to the trap door and to the guide posts, the guide collar being mounted to the guide posts for movement relative thereto and between said positions and locking the trap door in the lowered position,
[0030] a lock wheel for releasably holding the guide collar in the raised position and the trap door proximate to the top wall of the cage, the lock wheel being rotatable from a holding position for holding the guide collar in the raised position to a releasing position for releasing the guide collar and trap door,
[0031] a tripper mechanism responsive to the animal entering the cage and operable to release the lock wheel for rotation between said holding and releasing positions, and
[0032] a resetting mechanism for resetting the trap door in the raised position, the resetting mechanism including at least a portion of said guide collar acting on said lock wheel to rotate said lock wheel into the holding position.
[0033] A feature of this invention is an animal trap comprised of screen, open mesh, expanded metal and the like construction, which enables wind to pass through without the cage tumbling and allows the bait to be seen and detected by an animal.
[0034] Another feature of this invention is an animal trap which efficiently and safely captures small animals, such as rats, skunks, raccoons and other varmints or the like, for relocation.
[0035] A desirable feature of the gravity operated and/or spring assisted animal cages described herein above is the simplicity of design, trap setting, ease of animal release, and trap resetting. In a first embodiment, re-setting is staged by the brace member being disengaged and folded over onto the trap door and the combination snapped into the raised position. In a second embodiment, the cage is merely turned 180° over onto itself, causing the guide collar which is coupled to the trap door, to move the trap door back to the raised position and lockingly engage with a lock member.
[0036] For a more complete understanding of the invention, reference is made to the following detailed description and accompanying drawings. In the drawings, like reference characters refer to like parts throughout the several views in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] [0037]FIGS. 1 and 2 are perspective views, looking rearwardly and forwardly, respectively, of a first embodiment of an animal trap according to the present invention, the animal trap including a closure arrangement and trap door therefor that is spring-loaded and operates under the force of gravity.
[0038] [0038]FIGS. 3A and 3B are side and front elevation views of the animal trap, with portions of side wall material removed to show detail, illustrating a trip lock arrangement maintaining a trap door in a raised (cage open) open position whereby to permit animal entry into the cage.
[0039] [0039]FIGS. 4A and 4B are side and front elevation views of the animal trap, corresponding to FIGS. 3A and 3B, respectively, illustrating the trip lock arrangement and the trap door in a lowered (cage closed) position whereby to prevent the animal escaping from the cage.
[0040] [0040]FIGS. 5 and 6 are perspective views, looking rearwardly and forwardly, respectively, of a second embodiment of an animal trap according to the present invention, the animal trap including a closure arrangement and a trap door therefor that uses the force of gravity to close and reset the trap door.
[0041] [0041]FIGS. 7A and 7B are side and front elevation views, respectively, of the animal trap of FIGS. 5 and 6 and illustrate a trip lock arrangement maintaining the trap door in a raised (cage open) open position whereby to permit animal entry into the cage.
[0042] [0042]FIGS. 8A and 8B are side and front elevation views of the animal trap, corresponding to FIGS. 7A and 7B, respectively, and illustrate the trip lock arrangement and the trap door in a lowered (cage closed) position to prevent the animal from escaping from the cage.
[0043] [0043]FIGS. 9A and 9B are partial cutaway views corresponding to FIGS. 7A and 7B, respectively, and show the trap door and a latch member in the raised (cage open) position, and the trap door after having been released and moving downwardly towards the lowered (cage closed) position.
[0044] [0044]FIGS. 10 and 11 are partial views of a modified trap door assembly in a door closed and a door open position, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] Turning now to the drawings, according to this invention, FIGS. 1 - 4 and FIGS. 5 - 9 , respectively, illustrate preferred embodiments of an animal trap for small animals, the traps being denoted generally by the numbers 10 and 100 . As will be detailed herein below, the animal traps 10 and 100 are similar to each other in that each includes a generally rectangularly formed cage member formed of a mesh or suitably apertured material, has an opening at a front end thereof for an animal to enter, a door closure arrangement that includes a trap door that rotates under the force of gravity from a raised to a lowered position, and a trip lock arrangement that is releasably connected to the trap door and triggered by the animal.
[0046] The embodiments primarily differ from one another in the operation of the closure and trap door arrangement. In the animal trap 10 the trap door operates, in part, under the force of gravity and under the action of a spring member. In the animal trap 100 , the trap door closes solely under the force of gravity.
[0047] Turning to the first embodiment, and in particular to FIGS. 1 - 4 , the animal trap 10 comprises an elongated, generally rectangularly shaped, mesh cage. The cage has generally parallel top and bottom walls 14 and 16 of rectangular shape, generally square front and back walls 18 and 20 , and a pair of generally parallel sidewalls 22 and 24 of rectangular shape joining the top, bottom, back and front walls. The cage or enclosure defines an interior for trapping the animal and which is enterable only through an opening 12 formed centrally of the front wall 18 .
[0048] Each of the walls 14 , 16 , 18 , 20 , 22 and 24 are formed by a rectangular grid of reinforcement members 26 to provide body and strength to the enclosure and by a mesh screen 28 to form a complete closure. Preferably the reinforcement members and mesh screen are comprised of steel.
[0049] Additionally, if desired, primarily depending on the size and nature of the animal to be trapped, the cage could be constructed in a more durable fashion. In particular, according to this invention, the walls and door of the cage may be comprised of a woven wire openwork construction, or what is oftentimes referred to in the art as “expanded” sheet metal. Expanded sheet metal is the result of a process whereby a single sheet of metal is simultaneously cut or slit and then opened by stretching the sheet whereby to produce a mesh or latticework comprised of a series of diamond-shaped openings. Desirably, the general shape of the cage enclosure can be made by the use of only a single sheet of expanded metal that is provided with three 90° bends whereby to form the walls 14 , 22 , 16 , and 22 , and to which shape are attached the front and back walls 18 and 20 . The cage walls would be adjoined by any suitable method, such as by welding or other method known by those skilled in the art.
[0050] However, if suitably dimensioned, the walls and mesh could be comprised of a suitable polymeric material, wood, reed or other natural material. It is to be understood that many materials that are apertured (or comprised of a foraminous material) would suffice and be known to those skilled in the art. Importantly, the walls of the cage should be suitably apertured to enable the animal to see and smell bait placed in the interior of the cage.
[0051] According to this invention, the front wall 18 is at an acute angle to the bottom wall 16 and is generally disposed at an angle of about 40°-60° thereto. Preferably, the front wall 18 is at an angle of about 45° to the top and bottom walls 14 and 16 and forms the hypotenuse of a 45° right triangle.
[0052] A trap door 30 of generally rectangular shape and having a top and a bottom edge portion 32 and 34 , respectively, is hingedly affixed at the top edge portion 32 thereof to the front wall 18 of the cage. Preferably, the trap door 30 is constructed in a manner similar to that of the above described wall members and comprises a rectangular grid of horizontally and vertically extending reinforcement members 26 and a mesh screen 28 secured thereto. The trap door 30 , the opening 12 and the front wall 18 are generally rectangular and/or square in shape, concentric with one another, and the door dimensioned to be slightly larger than that of the opening.
[0053] Two or more cylindrical or ring shaped sleeves or hinge members 36 are laterally spaced and fitted about the topmost horizontally disposed reinforcement member 26 on the trap door 30 and a horizontally disposed reinforcement member 26 on the front wall 18 . By such connection, the trap door 30 is rotatably mounted to the cage for rotation relative thereto about at an axis “A”. The trap door 30 rotates between a first (cage open) position raised above the front opening 26 and generally horizontally disposed relative to the top and bottom walls 14 and 16 , and into a second (cage closed) position disposed in lowered covering relation with the front opening and partially engaged with the front wall 18 .
[0054] A trip lever or trip plate 38 of generally rectangular shape and having a top and a bottom edge portion 40 and 42 , respectively, is hingedly affixed at the bottom edge portion 42 thereof to the bottom wall 16 of the cage in the back of the enclosure. The trip lever or trip plate 38 is tripped (i.e., depressed) by the weight of an animal crawling thereover trying to get to bait “B” placed in the back of the cage.
[0055] Preferably, the bait is not attached to the trip plate. The bait would be positioned between the back wall 20 and the trip plate 38 .
[0056] The trip plate 38 is of similar construction as the walls and comprises a rectangular grid of reinforcement members 26 covered with mesh 28 . Two or more cylindrical or ring shaped sleeve or hinge members 36 are used to connect a reinforcement member on the bottom wall 16 and which extends laterally between the sidewalls 22 and 24 to a corresponding horizontally disposed reinforcement member on the trip lever 38 . By such mounting, the top edge portion 40 of the trip plate 38 is adapted to rotate about an axis “C” and about the plane of the bottom wall 16 and move towards the bottom wall 16 of the cage.
[0057] Although the trip plate 38 is shown as being angled upwardly towards the front wall, the trip plate could also angle upwardly towards the back wall 20 . Additionally, although shown as being hingedly connected to the bottom wall, the trip plate 38 could be mounted for rotation to a support bar (See FIGS. 5 - 9 ) that extends between the side walls.
[0058] An axially elongated trip (or actuator) rod 44 is rotatably mounted to the sidewall 22 of the cage and extends between the trap door 30 at the forward end of the cage and the trip plate 38 at the rearward end of the cage. Two or more or more cylindrical or ring shaped hinge members 36 are used to connect the trip rod 44 to a horizontally extending reinforcement member 26 forming the sidewall 22 . The trip rod 44 includes an L-shaped link or catch member 46 at the forward end thereof for seating under a side edge 48 of the trap door 30 and maintaining the trap door in the first (cage open) position. As will be described hereinbelow, rotation of the trip rod 44 about its axis “D” operates to dislodge the catch member 46 from engagement with the trap door and release the trap door for closing movement.
[0059] A linkage structure comprising first and second links 50 and 52 connects the trip rod 44 to the trip plate 38 . The first link 50 extends transversely from the trip rod 44 at the rearward end thereof and is generally parallel to the top wall 14 when the catch member 46 holds the trap door 30 in the cage open position. The second link 52 is arranged vertically and has a first end 54 hingedly connected to the first link 50 and a second end 56 hingedly connected to a reinforcement member 26 along the edge of the trip plate 38 .
[0060] A spring operated locking structure comprising a brace member 58 , a catch member 60 and a coil spring 62 is provided for biasing the trap door 30 towards the second (cage closed) position in covering relation to the opening 12 and releasably maintaining the trap door in the second position.
[0061] The brace member 58 is generally planar, rectangularly shaped, and is of similar construction as the walls and comprises a rectangular grid of reinforcement members 26 covered with mesh screen 28 . In particular, the brace member 58 has first and second edge portions 64 and 66 and is hingedly affixed at the first edge portion 64 thereof to the trap door 30 proximate the bottom end portion 34 thereof. Two or more cylindrical or ring shaped sleeve or hinge members 36 are used to connect a laterally extending reinforcement member on the trap door 30 to a laterally extending reinforcement member on the brace member 58 .
[0062] By hingedly mounting the first edge portion 64 to the trap door, the second edge portion 66 of the brace member 58 is adapted to rotate about an axis “E” relative to the trap door. As will be described, the brace member 58 is initially horizontally disposed between the trap door and the top wall 14 in folded, confronting relation above the trap door. Upon release, the trap door is movable by gravity and in a “springing movement” by the brace member 58 vertically downwardly and into a substantially vertical orientation, the bottom end portion 34 of the trap door being driven against the bottom wall 16 and the trap door being disposed against the front wall 20 and in covering relation with the opening 12 .
[0063] The catch member 60 is in the form of a pair of L-shaped catch links, which extend downwardly from the top wall 14 of the cage for engaging the second edge portion 66 of the brace member 58 . Preferably, the catch links 60 are extensions of a reinforcement member that forms part of the top wall 14 . It is to be understood, however, that the catch links could extend from the sidewalls, if desired.
[0064] The coil spring 62 has a first end connected to a reinforcement member of the trap door 30 at the bottom end portion thereof and a second end connected to a reinforcement member of the brace member 58 . When the trap door is in the first (cage open) position, the coil spring 62 biases the free edge portion 66 of the brace member 58 against the top wall 14 and the bottom end portion 34 of the trap door away from the top wall. Upon rotation of the actuator rod 44 , the catch member 46 is released from the trap door, and gravity causes the (free) bottom end portion 34 of the trap door to fall. The force of the coil spring 62 causes the brace member 58 to flip or swing away from the trap door, substantially simultaneously driving the second edge portion 66 of the brace member 58 towards and into engagement with the catch link(s) 60 , and the first edge portion 64 (and bottom end portion 34 of the trap door 30 ) towards the bottom wall 16 , resulting in the brace member 58 forcing the trap door downwardly and against the front wall 18 .
[0065] In the first position, the brace member 58 is folded onto the trap door 30 and squeezed between the trap door 30 and the top wall 14 of the cage, the top wall 14 , the brace member 58 and the trap door 30 being generally parallel to one another. The free end or second edge portion 66 of the brace member 58 is spring loaded or biased by the coil spring 62 against the top wall 14 thereby urging the trap door 30 and the brace member 58 away from the top wall 14 . The coil spring 62 , acting proximate to the hinged connection between the brace member 58 and the trap door 30 , urges the brace member and the trap door downwardly and away from the top wall 14 of the cage. The coil spring 62 acts to rotate or pull the brace member 58 away from its overlapped relation with the trap door and drive the trap door into the second position against the front wall 18 .
[0066] In the second (cage closed) position, the brace member 58 and the trap door 30 are at an acute angle to one another. As noted above, the front wall 18 forms the hypotenuse and the brace member 58 and trap door 30 the legs of a 45° right triangle to provide for maximum force against the trap door. The brace member 58 is generally vertically disposed with its second edge portion 66 positioned proximate the top wall 14 and engaged by the L-shaped catch members 60 formed with the cage structure and its first edge portion 64 forcing the trap door into the closed position.
[0067] In operation, the user would place bait “B” in the back of the cage, between the back wall 20 and the trip plate 38 . The animal would enter the cage through the front opening 12 and proceed to the bait, stepping onto the trip plate 38 , the weight of the animal causing the trip plate to move in a downwardly direction “F” towards the bottom wall 16 of the cage.
[0068] Downward rotation of the trip plate 38 is transmitted by the link 52 to the trip rod 44 via the first link 50 at the rearward end of the trip rod 44 . Due to its hinged connection, the link 50 rotates (i.e., moves) in a downwardly direction “G” and the trip rod 44 rotates relative to is axis “D”, causing the forward end thereof to rotate and the catch link 46 to rotate in the direction “H” and be dislodged from its engagement with the side edge 48 of the trap door 30 whereupon gravity and the coil spring 62 act to drive the trap door downwardly and into closing relation against the front opening 12 .
[0069] Simultaneously with release of the trap door, the free edge portion 66 of the brace member 58 drives the free end 34 of the trap door downwardly away from the top wall 14 , springs upwardly and away from the trap door, and is captivated in the catch links 60 extending from the top wall 14 . The hinged first edge portion 64 of the brace member 58 drives the trap door downwardly against the front wall 18 . The acutely angled front wall 18 and relationship between the trap door and brace member result in the brace member being generally vertically disposed with the hinged end of the brace member driving the free end of the trap door firmly into a closed position.
[0070] To open or reset the animal trap, the user substantially simultaneously forces and rotates the brace member 58 away from the catch links 60 and towards the front wall 18 and the trap door towards the top wall. Sufficient upward movement will bring the trap door into lodged engagement with the catch link 46 .
[0071] Turning now to FIGS. 5 - 9 , a second embodiment of an animal trap according to this invention, generally indicated by the number 100 , comprises an elongated, generally rectangularly shaped cage that is closed on five of its sides with the side corresponding to the front wall thereof defining a closable front opening 112 sized to permit entry of a small animal into the cage to obtain bait “B” placed in the rearward (interior) end of the cage.
[0072] In particular, the cage is formed by a top and a bottom wall 114 and 116 , a pair of opposed sidewalls 122 and 124 , and a back wall 120 . A trap door 130 for closing the front opening 112 is hingedly connected to the cage by an axially elongated support bar 136 and is adapted to rotate relative to the support bar and the front opening from a raised (cage open) position to a lowered (cage closed) position. In the raised position, as shown by reference to FIGS. 5, 6, 7 A, 7 B, and 9 A, the trap door is generally horizontally disposed relative to the top and bottom walls 114 and 116 and in juxtaposition with the top wall 114 . In the lowered position, as shown by reference to FIGS. 8A and 9B, the trap door is at an acute angle to the top and bottom walls.
[0073] Preferably, the walls 114 , 116 , 122 , 124 and 120 of the cage and the trap door 130 are formed of expanded sheet metal, as described hereinabove. In such construction, a single continuous planar rectangular sheet of expanded metal is bent to form the walls 114 , 122 , 116 and 124 , and the two free edges of the sheet thus bent are adjoined (e.g., welded together) to form a rectangular shell structure that is fixedly secured (e.g., welded) to the back wall 120 and in encircling relation thereto whereby to form the rectangular cage having an open front.
[0074] The trap door 130 is generally planar, rectangularly shaped, and includes a top edge portion 132 that is hingedly secured to the support bar 136 for rotation relative thereto and a bottom edge portion 134 . The support bar 136 has its opposite axial ends 136 a and 136 b , respectively, secured to the sidewalls 122 and 124 whereby to be disposed in generally parallel relation to the top and bottom walls 114 and 116 and to position the top edge portion 132 of the trap door proximate to the top wall 114 .
[0075] In the embodiment shown, the length of the trap door (i.e., the distance between the opposite edge portions 132 and 134 ) is somewhat greater than the vertical height (i.e., the distance between the top and bottom walls 114 and 116 ) of the cage, and the width of the trap door is less than the distance between the sidewalls 122 and 124 . As such, when mounted, the trap door may swing relative to the cage walls and between the raised and lowered positions.
[0076] When in the lowered (or cage closed) position, the trap door is oriented at an acute angle to the top and bottom walls 114 and 116 . The bottom edge portion 134 of the trap door engages the bottom wall 116 and the trap door angles inwardly and upwardly towards the top wall.
[0077] As will be appreciated from the discussion herein below, a steeper angle will contribute to a trap door closure that is more difficult for the animal to dislodge. However, if too steep, the door may not rotate rapidly and function in the manner of a drop gate. Preferably, the trap door is disposed at an angle of between 60° and 80° relative to the bottom wall 116 . More preferably, the trap door is at an acute angle of about 75° to the bottom wall.
[0078] A guide structure is provided for guiding the trap door between the raised and lowered positions. Preferably, the guide structure includes a pair of axially elongated guide rods 168 and 170 and a generally rectangularly shaped guide collar 172 .
[0079] The guide rods 168 and 170 , respectively, have opposite end portions 168 a and 168 b and 170 a and 170 b that are connected to the cage and space the axially extending portion of each guide rod so as to be forwardly from the front opening of the cage and in parallel relation to one another and to the sidewalls 122 and 124 . As shown, the end portions 168 a and 170 a , and 168 b and 170 b , respectively, are fixedly connected to the top and bottom walls 114 and 116 . As connected, the axes of the guide rods are generally perpendicular to respective planes including the top and bottom walls 114 and 116 and the axis of the support bar. If desired, the end portions of the guide rods could be connected to the sidewalls 122 and 124
[0080] In the embodiment shown, a folded-over reinforcement plate (or frame) 126 is secured to the edges of the trap door and also to the free end portions of the walls 114 , 122 , 116 , and 124 of the expanded metal sheet structure whereby to reinforce (or rigidify) the trap door 130 and the front opening 112 . Preferably, the opposite end portions 168 a , 168 b and 170 a , 170 b of the respective guide rods 168 and 170 are fixedly connected to the portion of the reinforcement frame 126 that extends along the top and bottom walls 114 and 116 .
[0081] The guide collar 172 is adapted to connect the trap door 130 to the guide rods 168 and 170 and constrain the combined vertical and rotational movement of the trap door relative to the front opening 112 of the cage. The guide collar 172 comprises a pair of axially elongated guide beams 174 and 176 connected to a pair of centrally bored guide sleeves 178 whereby to form a rectangular shaped opening sized to fit about the trap door. The guide sleeves 178 are mounted to a respective guide rod 168 and 170 for sliding movement therealong.
[0082] In the embodiment shown, when the guide sleeves 178 are mounted to the guide rods, the guide beams 174 and 176 are generally horizontally disposed and in parallel spaced apart relation with one another and with the top and bottom walls 114 and 116 . The guide beams 174 and 176 are in juxtaposition with the exterior and interior faces of the trap door (i.e., distal and proximate to the cage interior) with the guide rods spacing the guide beam 174 outwardly from the front opening of the cage.
[0083] As an important feature of this embodiment, the guide beam 174 serves several functions. First, the guide beam 174 functions as a handle for carrying and positioning the cage. The guide beam or handle 174 enables the user to carry the cage to a location for trapping an animal and also to carry the cage with a trapped animal to a remote location for release. Further, the guide beam or handle enables the user to position or otherwise maneuver the cage, such as for turning the cage 180° onto itself and positioning the top wall 114 so as to be engaging the ground, such as for effectuating release of an animal and resetting of the cage.
[0084] Second, the guide beam 174 provides the user with a way to set/reset the trap. The user grasps the handle and lifts the guide collar 172 upwardly, causing the interiorly disposed guide beam 176 to engage the rear (interiorly facing) side of the trap door and progressively cam the trap door upwardly, enabling the user to access an actuator rod 140 , a release plate 164 , and a coil spring 162 therewithin—useful in setting/resetting the trap. The trap setting, resetting and/or trap release operation is described in greater detail herein below.
[0085] Preferably, a circular disc or spacer 170 is provided on the exterior guide beam 174 for spacing the axial extension of the guide beam 174 from direct contact with the exteriorly facing surface of the trap door. In some environments, problems might arise from material on the trap door resisting downward sliding movement between the guide collar and the trap door. The spacer disc 170 engages the trap door in a “point contact” and transmits gravity forces from the collar 172 to the trap door to enhance closing movement of the trap door.
[0086] Preferably and according to this invention, a releasable latching structure is provided for maintaining the trap door 130 in the raised or lowered positions. The latching structure comprises a trip plate 138 , a link arm 144 fixedly connected to the trip plate, the axially elongated actuator rod 146 having a rearward end portion 148 connected to the link arm 144 and a forward end portion 150 , and a latch keeper 152 releasably connectible to the forward end portion 150 of the actuator rod. The trip plate 138 is generally planar, rectangular in shape, and has a lateral width that is substantially the same as the distance between the sidewalls 122 and 124 . The trip plate is hingedly connected along a laterally extending bottom edge portion 142 thereof to a pivot bar 154 extending laterally between and connected to the sidewalls of the cage, such that a distal laterally extending top edge portion 140 of the trip plate is capable of rotation towards the bottom wall 116 of the cage. While the trip plate is preferably comprised of expanded metal, the plate may also be comprised of a mesh screen or like apertured material.
[0087] The link arm 144 is proximate to the pivot bar 154 and projects perpendicularly upwardly from the trip platel 38 to a connectible end portion 145 . The end portion 145 is pivotably connected to the rearward end portion 148 of the actuator rod 146 such that with downward movement (i.e., rotation) of the trip plate, the end portions 145 and 148 will rotate and/or move towards the back wall 120 of the cage and the link arm will pull the actuator rod 146 rearwardly and in a direction away from the latch keeper 152 .
[0088] The latch keeper 152 is connected to the cage by a plate member 153 and is proximate the top wall of the cage and the front opening thereof for releasably engaging the interior guide beam 176 . Preferably, the plate member 153 is connected to the reinforcement frame 126 forming the shape of the open end.
[0089] The latch keeper 152 comprises a latch housing 184 including forward and rearward housing portions 186 and 188 that form an elongated bore 190 for slidably receiving the forward end portion 150 of the actuator rod therewithin, and a U-shaped locking wheel 192 . The forward housing portion 186 is generally formed by a plate member having been folded-over to include a pair of parallel, vertically disposed, spaced-apart plate members. The locking wheel 192 is connected to the forward housing portion 186 by a pin 193 for rotation relative within the folded over plate members and between a locked and an unlocked position.
[0090] The locking wheel 192 includes an upper arm 194 proximate to the top wall, a central body portion provided with a locking detent 196 sized to receive the forward end portion 150 of the actuator rod, and a lower arm 198 provided with a shoulder 199 which is adapted to engage a lower edge 187 of the forward housing portion 186 . The locking detent 196 includes an axial flat and a shoulder portion and is formed by cutting away a portion of the locking wheel.
[0091] The lower edge 187 places a limit on the clockwise rotation (as viewed in FIG. 9A) of the lower arm 198 following release and downward movement of the trap door from the raised (cage open) position and positions the upper arm 194 for effectuating counterclockwise rotation (as viewed in FIG. 9B) of the locking wheel 192 following upward movement of the trap door from the lowered (cage closed) position back into the raised position.
[0092] An axially elongated, generally cylindrical coil spring 162 has opposite ends 162 a and 162 b , respectively, connected to the rearward housing portion 188 and the actuator rod 146 and acts to pull the forward end portion 150 of the actuator rod 146 towards the locking wheel 192 for locking engagement within the locking detent 196 therein. Preferably, the actuator rod is generally cylindrical and the coil spring is circumposed around the exterior of the actuator rod.
[0093] According to a particular feature of this invention, an axially elongated release plate 164 is slidably connected to the actuator rod and has an end portion thereof connected to the rearward end 162 b of the coil spring. Manual force on the release plate 164 in a direction away from the locking wheel 192 operates to axially withdraw the forward end portion 150 of the actuator rod from captured engagement within the locking detent 196 and releases the locking wheel for rotation and repositioning of the arms 194 and 198 .
[0094] Preferably, the forward end portion 150 and the axial flat of the detent 196 are formed with complementary tapered faces, indicated generally at 151 and 191 . Advantageously, when the trap door is in the raised (cage open) position (See FIG. 9A), the tapered face 151 of the actuator rod provides a smooth seated engagement with the locking detent. When the trap door is in the lowered (cage closed) position (See FIG. 9B), the tapered face 151 engages the outer periphery of the locking wheel 192 whereby to inhibit retrograde rotation of the locking wheel and maintain the locking shoulder 199 positioned against the lower edge 187 of the forward housing 186 . Further, upon resetting of the locking wheel, the tapered face 151 enhances smooth reentry into the locking detent.
[0095] In operation, to set the cage, the cage is taken to a location to trap an animal and the bottom wall placed on the ground. The exterior guide beam or handle 174 of the guide collar 172 is grasped and lifted vertically towards the top wall 114 . The trap door 130 is lifted slightly and the release plate 164 pulled rearwardly against the bias of the coil spring 162 , the plate pulling the actuator rod rearwardly from engagement within the locking detent, thereby releasing the locking wheel 192 for rotation. The locking shoulder 199 of the locking wheel 192 is rotated into position against the lower edge 187 of the forward housing portion 186 , thereby positioning the upper and lower arms 194 and 198 of the locking wheel to open downwardly.
[0096] Alternatively, to reset the trap, the cage could merely be turned over onto itself. The top wall 114 would be supported on the ground and the bottom wall 116 would be facing upwardly
[0097] The handle (exterior guide beam) 174 of the guide collar 172 is grasped and lifted vertically, causing the interior beam 176 to simultaneously engage and lift the trap door towards the top wall of the cage. Upon sufficient upward movement, the interior guide beam 176 engages the upper arm 194 of the locking wheel, causing the locking wheel and the upper and lower arms thereof to rotate. As a result, the locking detent 196 is rotated into alignment with the bore 190 , whereupon the forward end portion 150 of the actuator rod 146 is biased into the locking detent by the coil spring 162 . The animal trap is then set to capture an animal.
[0098] Bait is set into the interior of the cage, between the trip plate 138 and the back wall 120 . Because of the apertured expanded metal wall structure, a small animal can both see and smell the bait in the trap and be attracted thereto
[0099] A small animal enters the cage and steps on the trip plate 138 , causing the trip plate 138 to be depressed, the trip plate and link arm 144 to rotate, the actuator rod to be pulled rearwardly, and the forward end portion 150 of the actuator rod to be withdrawn from the locking detent. The locking wheel 192 is released and rotates relative to the forward housing portion 186 , causing the upper and lower arms 194 and 198 thereof to rotate and be oriented so as to open downwardly (towards the bottom wall of the cage). Rotation of the lower arm 198 releases the interior guide beam 176 of the guide collar and brings the shoulder 199 of the arm 198 into engagement with the lower edge 187 of the forward housing portion 186 , whereupon the tapered face 151 at the forward end of the actuator rod is driven against the locking shoulder to maintain the locking wheel in the rotated to position.
[0100] Substantially simultaneously with the actuator rod being disconnected from engagement with the locking detent, the force of gravity will act to rotate the lower arm, whereupon the guide collar and any “enhancement” weights that may have been added to the trap door and/or guide collar will cause the guide collar and the trap door to fall. The lower edge portion 134 of the trap door will come to rest on the bottom wall 116 and be positioned thereagainst by the guide collar.
[0101] The guide collar 172 will resist the trap door from opening as a result of any horizontal opening forces transmitted against the trap door by an animal trying to escape from the cage. That is, the collar will inhibit vertical rise of the trap door.
[0102] For release, the exterior guide beam or handle 174 is grasped, and used to carry the cage and trapped animal to a desired release location. The handle is again grasped and the animal cage is turned 180° such that the top wall 114 is on the ground. At this point, gravity will cause the guide collar 172 and the trap door to fall towards the top wall. The interior guide beam 176 will act against the interior wall of the trap door and gravity will urge the guide collar against the trap door and the guide collar and the trap door to fall downwardly towards the locking wheel.
[0103] The guide beam 176 will fall into the space between the upwardly open arms 194 and 198 , engage the upper arm 198 , and cause the locking wheel to rotate, thereby causing the locking detent to be rotated into alignment with the actuator rod. The coil spring will then bias the forward end portion of the actuator rod into the locking detent, resetting the animal cage for another trapping.
[0104] Accordingly, there is provided herein animal cages for capturing, without harming, small animals, the cages being simple, efficient, having positive closure arrangements that are gravity and/or gravity and spring assisted in operation.
[0105] Although various embodiments of the invention have been disclosed for illustrative purposes, it is to be understood that one skilled in the art can make variations and modifications without departing from the spirit of the invention.
[0106] In a further embodiment hereof and as shown in FIGS. 10 and 11, it is contemplated that the guide mechanism or assembly that engulfs the cage door, i.e., the guide rods, guide collar, and guide beams may be replaced with a handle assembly.
[0107] In accordance herewith, a cage door 210 has an outwardly and laterally extending door latch rod 212 secured thereto. The door latch rod 212 is fixed to the cage door 210 by any suitable means such as by welding or the like and is used to raise the door to a cage open position. Alternatively, the handle may be pivotally secured to the door.
[0108] As shown the latch mechanism, generally denoted at 214 includes a keeper assembly 216 and a rotatable wheel 218 similarly constructed to the wheel and rod 192 , 193 discussed hereinabove. However, according hereto, the handle 212 is positively locked between the upper and lower areas 194 , 198 , respectively, of the wheel 192 .
[0109] Thus, when the rod is raised it causes the door to rotate upwardly therewith. When the rod engages the arm 194 it causes rotation of the wheel 192 and the detent 196 is positively locked by the rod 150 in the manner heretofore discussed. When the plate 138 is positioned in the same manner discussed hereinabove, rotation of the wheel about the pin 193 releases the rod 212 permitting the door 210 to drop.
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A live animal trap for capturing and restraining a small animal comprises a rectangular mesh cage having an open front sized to admit an animal to be trapped, and a trap door hingedly affixed to the cage and movable between raised and lowered positions, respectively, permitting entry to and preventing escape from the cage. Embodiments are disclosed of gravity and/or spring assisted latching and tripping structures for releasably securing the trap door in the open position and responsive to an animal seeking to get to bait in the back of the cage. In one, a spring assisted brace member is hingedly affixed to and drives the lower end of the trap door into the closed position. In another, a multipurpose guide collar locks and drives the trap door in and for movement between the raised and lowered positions, and assists in animal release and in resetting of the trap.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to hydraulic actuator devices and more particularly to such devices which hydraulically drive linear or rotary actuators.
2. Description of the Prior Art
It has long been recognized that hydraulic, as opposed to purely mechanical or electromechanical actuation is more desireable for certain applications. One reason for this is that hydraulic systems have been found more practical in applications requiring high reliability and large force/velocity capability combined with rapid response. For example, a majority of commercial and military aircraft today use hydraulic actuation for their primary flight control surfaces. However, hydraulic servoactuation has certain limitation, foremost of which is the need for a central hydraulic supply system. A hydraulic pump is required, together with a prime mover to drive the pump, a reservoir, an accumulator, piping to convey the hydraulic pressure to each remotely located servoactuator, etc. There is considerable cost and installation expense, potential maintenance problems due to leakage from the piping, substantial energy losses at the pump, undesirable noise, and for aircraft installations considerable weight and bulk of hardware.
There have been many attempts to replace hydraulic servoactuation systems with electromechanical servoactuation systems, thereby eliminating the central hydraulic supply system. These attempts have accelerated, due to recent development in servomotors using rare earth permanent magnets, and recent developments in the electronic control hardware that such motors require. However, the necessary gearing (and often clutches) between such improved electric motors and the load have emerged as the weak link, and have not improved to the degree necessary to replace hydraulic servoactuation in many applications.
The present invention uses electric motor actuation rather than a central hydraulic supply, but substitutes a self-contained hydraulic transmission for the mechanical transmission. This avoids many of the problems which have not been able to be solved in the mechanical clutches and gears. For example, the present invention can provide an effective gear ratio of 2,000 to 1 or higher between the motor and load, without using any gears. This eliminates the gear tooth fatigue problems encountered in electromechanical servoactuators. The need for clutches in redundant mechanical systems is eliminated; a failed servoactuator constructed in accordance with the present invention can be backdriven by other parallel servoactuators.
Another problem that has long plagued hydraulic systems is leakage. Leakage is essentially eliminated in the present invention by means of a design which provides only one possible leakpoint, rather than the many such potential leakpoints in the prior art. This results in greatly reduced maintenance expense.
Still another problem of prior hydraulic systems is filtration of the fluid. Conventional filtration of the hydraulic fluid is not possible where the flow of the hydraulic fluid is not unidirectional. Flow reversals sweep out contaminant particles created by pump wear. The present invention provides a filtration design which solves this problem, assuring long life for the servoactuator.
In the present invention, the electric motor drives the hydraulic pump on a demand basis, generating only the required pressure and flow. Compared to the prior art, this conserves energy, reduces electrical power costs, and also generates less noise (important in industrial applications). This creates a drive of high efficiency. Still further, the present invention provides self contained failure detection capabilities to reduce maintenance costs.
SUMMARY OF THE INVENTION
It is, therefore, an objective of the present invention to provide a self-contained hydraulic actuator which can be operated electrically. It is also an objective of the present invention to provide such a device which can be monitored electrically. Another objective of the present invention is to provide such a device which is reliable, light weight and compact.
It is also an objective of the present invention to provide an electro-hydraulic actuator with improved sealing characteristics. Yet another objective is to provide such an actuator with an improved filtration ability and an improved actuator rod positioning ability. Still further, it is an objective to provide such an actuator with an improved failure detection system.
In accordance with these and other objectives, the present invention provides an electro-hydraulic actuator which includes an actuator rod having a piston thereon for moving the rod by hydraulic pressure. A fixed displacement bi-directional hydraulic pump is provided for pumping hydraulic fluid to move the actuator rod. A reversible electric motor is mechanically connected to and drives the hydraulic pump. An actuator manifold contains the pump and a reservoir of hydraulic fluid in which the electric motor is submerged. The manifold also includes the actuator cylinder which contains the piston and hydraulic passages connecting the pump to the hydraulic reservoir and the cylinder as required for moving the actuator rod.
The cylinder chamber in which the piston moves is divided by the piston into a "retract" chamber at the forward end and a "extend" chamber at the rearward end of the cylinder. A one way filter system can be provided for either or both of the "retract" and "extend" chambers. The one way filter system is comprised of a passage having a filter and check valve therein allowing fluid flow through the filter only as fluid moves to supply the actuator chamber for a "retract" or "extend" direction of motion. This prevents backwash of contaminants from the filter as reverse flow occurs, while still providing a single filter unit for each actuator package.
In an embodiment where the front or retract chamber of the cylinder has a different volume than the rear chamber, movement of the piston causes an imbalance of hydraulic fluid which is preferably compensated for by an improved rotating piston pump constructed in accordance with the present invention. This piston pump has an asymmetrical port plate. The first port of this plate has a different radial extent from the second port which provides different sizes for the first and second ports. These sizes are matched to the volume/rod movement ratio of the chamber to which each of the ports is open when the pump rotates. A third port allows the pump to drive the differential volume of hydraulic fluid to and from a variable volume chamber.
The pump and motor of the present invention are preferably reversible variable speed devices, to allow variable speed movement of the actuator rod in either direction by means of electrical signals to the motor. Also, it is preferable that a variable displacement gas reservoir be disposed adjacent to the hydraulic reservoir chamber and separated therefrom by a movable membrane. This movable membrane allows volumetric changes due to thermal gradients of the hydraulic fluid.
Separate temperature sensors are provided in the hydraulic and gas reservoirs of the present invention to measure temperature changes in the gas reservoir and the reservoir of hydraulic fluid. In addition to the temperature measurement the sensors can detect, by the rate of temperature change, the presence of gas in the hydraulic fluid or the presence of oil in the gas chamber.
Also preferably, the present invention provides a position sensor connected to the actuator rod which is driven by the piston of the hydraulic cylinder. In addition, the hydraulic circuit is provided with a load limiter/relief valve, which limits the actuator force output to a preset value.
For a further understanding of the invention, and further features, objectives, and advantages thereof, reference may be had to the following description taken in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross sectional view of a device constructed in accordance with the present invention.
FIG. 2 is a plan view of the device shown in the FIG. 1.
FIG. 3 is a cross sectional view of a portion of the device shown in FIG. 1.
FIG. 4 is a schematic view of a portion of the device shown in FIG. 1.
FIG. 5 is a schematic view of the same type as shown in FIG. 4 showing an alternate embodiment of a device constructed in accordance with the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1 and FIG. 2, a device constructed in accordance with the present invention is shown at 11. The device shown is an actuator of the type used to control flight surfaces in an aircraft.
Although the device 11 is designed specifically for an aircraft, those skilled in the art will recognize that this electro-hydraulic actuator can be adapted for use in many other applications. The device 11 includes a trunion 12 which is formed at one end of the housing 13 to allow the electro-hydraulic actuator 11 to be attached to the structure of an aircraft. The rod end of the actuator shaft 15 can be attached to the flight surface to be moved by the actuator 11.
The housing 13 is comprised of a single piece which extends from an hydraulic fluid reservoir 17 to a cylinder chamber 19 in which a piston 20 moves. The piston 20 is attached to shaft 15 and divides the cylinder chamber 19 into a front chamber 22 and a rear chamber 24.
Disposed within the reservoir 17, and immersed in the hydraulic fluid which fills the reservoir 17, is a hydraulic pump 23 driven by an electric motor 25. The electric motor 25 drives the pump 23 to move hydraulic fluid between the chambers 22 and 24 to extend or retract the actuator shaft or rod 15. Hydraulic fluid passages 27 are machined in housing 13 to port the fluid between the pump 23 and the chambers 22 and 24.
The pump 23 and the electric motor 25 are reversible and operate so that as fluid is being supplied to one of chambers 22 and 24 it is being drawn from the other of the chambers 22 and 24. In this way, the extension and retraction of the actuator rod 15 is positively driven by the pressure of the hydraulic fluid in both of chambers 22 and 24. The pump 23 is bolted to the housing 13 and connected to the motor 25 by a shaft coupling 37. A pin 33 indexes the motor 25 so that the motor 25 is held fixed with respect to the housing 13. Wires 26 disposed in a cavity 28 in housing 13 provide electric power to electric motor 25. A plate 39 separates the portion of reservoir 17 containing the motor 25 from the portion of reservoir 17 containing pump 23. Seals and bearings 41 are provided in plate 39 surrounding shaft 37.
The region surrounding the pump 23 and the interior of the motor 25 are at the reservoir pressure. Consequently, leakage from the pump does not cause leakage of hydraulic fluid from the system; the leakage simply returns to the reservoir, where the fluid is reused. Similarly, no pressure seals are required between the pump 23 and motor 25 interior, eliminating a source of wear and failure present in the prior art.
The portion of the hydraulic reservoir 17 which extends around the motor 25 is provided with heat exchanger fins 35. Because the reservoir 17 is filled with hydraulic fluid, heat from the motor 25 can be rapidly transferred to the housing 13 and dissipated by the fins 35. This advantage results from immersing the motor 25 in hydraulic fluid.
Another advantage of this arrangement of parts is the relatively low weight of hydraulic fluid required to operate the actuator. Relatively little volume of hydraulic fluid is required other than the amount necessary to fill the front and rear chambers 22 and 24.
Referring now to FIG. 3, the pump 23 is shown in more detail. The pump 23 is a piston type device. The pump shaft 37 is supported by bearings 43 rotates in a pump housing 45. An assembly of pistons such as pistons 49 and 51 are located in an array around the shaft 37 and connected to rotate therewith. The pistons 49 and 51 are moved in a reciprocating motion as they rotate by means of a swash plate 47 which is designed at a sufficient angle from a perpendicular to shaft 37 to cause the desired amount of fluid displacement by the pistons 49 and 51.
The pistons 49 and 51 are reciprocated in a piston manifold 48. As the pistons 49 and 51 reciprocate they move hydraulic fluid into and out of the pump 23 through openings 50 and 52 in manifold 48. The pump port plate 53 at the end of pump 23 has shaped openings (see FIG. 5) located adjacent the openings 50 and 52 as the pistons rotate, which directs the fluid to and from the passages 29 and 31.
As the shaft 37 rotates, hydraulic fluid is driven to and from the passages 29 and 31. Reversal of the motor and shaft rotation reverses the flow. Thus, the rate of hydraulic flow is directly proportional to the speed of rotation of the pump shaft 37.
Pumps of the type shown as pump 23 of the present invention are well known to those skilled in the art. Although such pumps are especially advantageous for the present invention, it is believed that other reversible hydraulic pumps could be used.
Operation of the motor 25 and pump 23 can result in the generation of heat. It is, therefore, desireable to monitor the temperature in the hydraulic fluid. Temperature sensor 61 is attached to the upper end of reservoir 17 for this purpose. In addition, however, sensor 61 has a resistance heating device which can be pulsed so that the temperature change caused by the heat from the pulsed heating device can be measured. If the decay characteristics of the temperature change following the pulsing of the heating device is too slow, this indicates that undissolved gas is present in the hydraulic fluid and maintenance of the actuator is required.
To allow for changes in the amount of the hydraulic fluid in the reservoir 17, an air filled metal bellows 58 is sealingly connected to the top of the reservoir. The bellows 58 is filled with an inert gas such as nitrogen and, therefore, can expand or contract with the amount of hydraulic fluid in the reservoir 17. A fill port 62 is attached to the housing 13 for filling the bellows 58. A temperature sensor 63 is attached to the housing 13 at upper end of the bellows 58 to allow the temperature of the gas to be measured. As with sensor 61, sensor 63 is provided with a thermocouple to allow the temperature decay characteristics of the gas to be monitored. This allows the presence of liquid in the bellows to be detected. A fill port 60 containing a filter 65 is provided for introducing hydraulic fluid to reservoir 17.
Fluid passages and cavities 67 are provided in the housing 13 to allow hydraulic fluid to be conveyed between various auxiliary components and to protect the system. For example, the passages and cavities 67 extend to the blind end of the housing, past the shaft seal of shaft 15, to prevent a build-up of hydraulic fluid at the end of shaft 15. The passages 67 also connect with a quick-disconnect fitting 66 to allow the actuator to be filled with hydraulic fluid.
The passages 67 also extend from the reservoir 17 to a pressure transducer 70. The pressure transducer 70 allows remote electrical monitoring of the static hydraulic pressure in reservoir 17. Pressure variations in the reservoir 17 may occur due to the thermal expansion or contraction of the fluid or due to depletion of the fluid caused by mechanical, structural or seal failure. The pressure transducer 70 allows remote electrical monitoring of the fluid pressure so that maintenance can be scheduled prior to failures and so that failures can be detected.
The passages 67 also connect the reservoir 17 to a loadlimiter relief valve 68. This valve 68 is connected to passages 29 and 31 to limit the hydraulic fluid loads in the front and rear chambers 22 and 24. When hydraulic pressure in either of these two chambers exceeds a predetermined force level of the load-limiter relief valve 68, fluid is relieved to the reservoir 17 through passages 67. The predetermined force level of the relief valve 68 can be adjusted by means of a spring which bears on a valve piston of the valve 68. Check valves are provided to prevent flow from chamber 22 to chamber 24 and vice versa, even through both are connected to relief valve 68.
A rotary position encoder 83 is attached to the housing 13 adjacent the shaft 15. The position encoder 83 operates by reading movement of a rack and pinion mechanism which forms a part of the encoder 83. The rack portion of the encoder is disposed parallel to and moves with the shaft 15. The rotation of the pinion is electrically detected and can be electrically remotely read so that the position of the shaft 15 is determined. In other words, the encoder 83 produces electrical signals which indicate the amount of extension or retraction of the actuator shaft 15. This allows a confirmation of the extend or retract commands given to the motor 25. It also provides a more direct reading of the location of the shaft 15.
Rotating piston pumps of the type shown in FIG. 3 are well known. However, the present invention provides an improvement to the porting in the pump port plate 53 to compensate for the type of actuator rod shown in FIG. 5. As shown in FIG. 5, the rod 15 does not extend through the piston head 20 so that the front chamber 22 has a different volume to rod movement ration than the rear chamber 24. In a conventional rotating piston pump, the ports 55 and 57 are symmetrical and, therefore, an equal amount of fluid is driven through each port. For an unbalanced piston as shown in FIG. 5, this requires some of the fluid to be pumped to or from a variable volume excess fluid reservoir.
The present invention provides an extra port 59 in the port plate 53 which balances the flow to or from a variable volume chamber 69. By controlling the size of port 59, a precise flow to and from the chamber 69 will balance the flows to chambers 22 and 24. This produces a much more efficient movement of fluid by providing a positive displacement of the fluid to and from the chamber 69. Check valves 71 and 73 can be provided to correct any slight differences in the flow to the chamber 69.
Referring now to FIG. 4, the present invention also provides an improved filtration of the fluid conveyed to and from the actuator "extend" and "retract" chambers 22 and 24. The "retract" passage 31 has a one way filter and a check valve 79 which allows fluid to pas through the filter 83 only in the direction from the pump 23 toward the "retract" chamber 22. A bypass circuit with check valve 81 allows fluid to flow only in the direction opposite the flow allowed by check valve 79.
Similarly, the "extend" passage 29 has a one way filter, and a check valve 77 which allows flow from pump 23 toward chamber 24. Flow from chamber 24 toward pump 23 passes through the bypass passage 74 around the filter 78.
Thus, the electro-hydraulic actuator system of the present invention is well adapted to obtain the objectives and advantages mentioned as well as those inherent therein. While presently embodiments of the invention have been described for the purpose of this disclosure, variations and changes in the construction or arrangements of parts can be made by those skilled in the art, which changes are encompassed within the spirit of this invention as defined by the amended claims.
The foregoing disclosure and showing made in the drawings are merely illustrative of the principles of this invention and are not to be interpreted in a limiting sense.
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An electro-hydraulic actuator having an electric motor disposed in a hydraulic fluid reservoir and connected to drive a hydraulic fluid pump. The actuator includes a piston rod which extends or retracts as a piston is hydraulically driven in a cylinder. An actuator housing forms the reservoir and cylinder and contains hydraulic passages connecting the pump, reservoir and cylinder. The actuator includes a one-way filter for filtering the hydraulic fluid. The hydraulic pump is preferably a rotating piston type and includes a port plate which allows the pump to drive the piston while the retract and extend chambers of the pump have different or unbalanced fluid drive ratios. A load limiting valve protects the system from excessive hydraulic pressure and a position sensor detects the position of the piston rod.
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RELATED CASE INFORMATION
[0001] The current application is a Continuation-In-Part of U.S. application Ser. No. 12/814875, filed Jun. 14, 2010 and U.S. application Ser. No. 12/408422, filed Mar. 20, 2009 which claims benefit of U.S. Provisional Application No. 61/039521, filed Mar. 26, 2008, the contents of which are incorporated herein in their entireties.
BACKGROUND OF THE INVENTION
[0002] Energy expended by people performing physical exercise can be converted into useful energy by using generators and other energy conversion devices. Human powered generators are well known and have been the subject of many patented inventions. For example, U.S. Pat. No. 4,389,047 to Hall and U.S. Pat. No. 3,210,643 to Stern each describe early human powered generators. However, devices for converting human power to useful energy have not become popular because the amount of energy that can be generated by a single person is quite small.
[0003] Collectively, the amount of energy expended by humans during exercise is very large. For example, in many fitness centers dozens of pieces of fitness equipment are used almost continuously during a given day. It would be desirable to redirect some of the energy expended by fitness center clients which is now almost entirely lost as heat, for use elsewhere by transmission to municipal public power grid. A system and method for collecting energy generated by human powered devices is described in Applicant's pending U.S. patent application Ser. No. 12/408,422 which is incorporated herein by reference in its entirety. In order to provide motivation to entice the public to participate in a system of human powered energy generation, it would be desirable to provide a system for tracking energy generated by exercise equipment and providing for rewards commensurate to an amount of power generated.
SUMMARY OF THE INVENTION
[0004] Illustrative embodiments of the present invention provide a system and method for securely measuring and tracking exercise performed by individuals and energy generated by human powered devices. An amount of exercise and/or energy generated is quantified and converted to reward points usable in a rewards incentive program. Exercise performed and/or energy generated on individual exercise equipment is measured by measurement apparatus on the equipment. In an embodiment of the invention, legacy exercise equipment, such as exercise equipment already in use may be retrofitted with a measuring apparatus, electric generator and/or user interface for use in accordance with embodiments of the invention.
[0005] Reward points are issued locally to a user's portable stored value device or card, or may be accumulated on a remotely administered user account. A user interface disposed locally with the exercise equipment receives a user identification and either provides points to the user's stored value device or card, or provides notification to the user of credits being provided to the remote user account. In an illustrative embodiment, the user identification is unique, protected, verifiable and secure.
[0006] A redemption point, in communication with remote user accounts, communicates over a network to verify sufficient credits and authorizes rewards to a user commensurate with available earned or awarded credits. The redemption point operator and/or the issuer of exercise points can also be rewarded for their participation in the exercise rewards program.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The foregoing and other features and advantages of the present invention will be better understood from the following detailed description of illustrative embodiments, taken in conjunction with the accompanying drawings in which:
[0008] FIG. 1 is a schematic block diagram illustrating a system for encouraging human powered energy generation according to an illustrative embodiment of the present invention; and
[0009] FIG. 2 is a process flow diagram illustrating a method for issuing exercise reward credits according to an illustrative embodiment of the present invention.
[0010] FIG. 3 is a process flow diagram illustrating method for exchanging exercise reward credits according to an illustrative embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0011] An illustrative embodiment of the invention provides an exercise credit exchange system and method in which a user enrolls to become a member of an exercise credit exchange program and may pay an enrollment fee, for example. Upon enrollment, the user is issued a memory device such as swipe card bearing a chip or magnetic strip, for example, a portable memory device or other type of “key”. When the member utilizes exercise equipment an amount of credit associated with their workout is registered on their key and on a corresponding user account maintained by a program administrator, for example. Keys can store the credit information themselves and/or may communicate the credit information via an electrical connection or wirelessly to a networked module for remote storage and/or administration, for example.
[0012] The amount of credit may be directly related to an amount of time that a user is using a particular piece of exercise equipment, an amount of work that the user performs using a particular equipment or some combination of time and work expended on the particular equipment, or achievement of a fitness goal, for example. Alternatively, the amount of credit may be awarded for time spent at a heath club or for simply visiting a health club. In an illustrative embodiment, the amount of credit is awarded based upon an amount of energy generated by a member and transmitted to a distribution grid as the user uses exercise equipment having generating/transmitting capability. Extra “green” points may be awarded for energy generated on certain types of equipment, or at certain locations, for example.
[0013] Points of varying amounts may be provided to reward certain other actions by the member, such as for joining a health club, making certain purchases or expenditures at a health club (for juices, power bars, food, coffee, water, equipment, clothing, locker rentals, preferred uses of facilities, etc.), for example. In an illustrative embodiment, reward points may be exchanged by a user for value, for example at a redemption point.
[0014] In the illustrative embodiment, the amount of credit and information aggregated by the member can be transported and transferred between or among members of the member's family or affinity group, for example, without regard to geographic location. The member's account information related to aggregation and use of exercise credits may be reviewable by the member over the Internet, for example.
[0015] The key and the user account are securely maintained to prevent tampering and to protect the integrity of the information stored. The exercise credits are transportable in that they may be earned/aggregated at any health/fitness club participating in the exercise credit exchange program wherever a member happens to be and with any participating partner, for example. In an illustrative embodiment, the exercise credits may also be aggregatable with other rewards programs, such as frequent flyer miles, for example.
[0016] The exercise credits correspond to or can be exchanged for or translated into rewards points that are redeemable for value such as cash, merchandise, discounts, air travel, hotel stays, or utility payments, for example. Illustratively, credits can be redeemable at the club level for value such as discounts or merchandise, at a participating partner for services/merchandise or from a financial institution such as a bank to initiate a banking relationship, or receive more favorable terms in an existing banking relationship, for example. Exercise credits may also be exchanged to receive discounted health insurance or life insurance premiums as indication of living a healthy lifestyle. In the illustrative embodiment, participating partners my also be required to pay certain fees to be allowed participation in the exercise credit exchange program.
[0017] The various embodiments of an exercise credit exchange system as described herein provide incentive to exercise, incentive to be loyal to participating health clubs and incentives to utilize services and/or products of participating partners. In addition to exchanging exercise credits for goods and services, it is envisioned that some number of exercise credits could be exchanged for carbon credits as part of a governmental or commercial cap and trade system of environmental regulation.
[0018] An exercise reward system according to an illustrative embodiment of the present invention is described with reference to FIG. 1 . The exercise reward system 100 includes at least one piece of exercise equipment 102 and a measurement apparatus 104 configured to quantify an amount of exercise performed by a user on the exercise equipment 102 . At least one electronic memory 106 is configured to store exercise credits identified to the user in response to the quantified amount of exercise performed.
[0019] In the illustrative embodiment, a user interface 108 is configured in communication with the measurement apparatus 104 . The user interface is configured for receiving a user identifier for identifying the credits for association with the user. In an illustrative embodiment, the user interface is configured for notifying the user of an amount of the credits associated with the user. At least one processor 110 is configured in communication with the measurement apparatus 104 . The processor 110 is configured to receive the quantified amount of exercise from the measurement apparatus 104 and convert the quantified amount of exercise to exercise credits based on a predetermined formula. In an illustrative embodiment, the predetermined formula can determine a credit amount based on bonuses or incentives, for example.
[0020] At least one network 112 is provided in communication with the processor 110 and configured for communicating the exercise credits to the electronic memory 106 . In an illustrative embodiment the electronic memory 106 may include a portable memory device such as a stored value card, a USB memory stick or an RFID transponder, for example.
[0021] The illustrative embodiment also includes a database 114 operable in conjunction with the processor 110 and the memory 106 for accumulating and storing exercise credits and corresponding user identifiers. At least one redemption point computer 116 can be configured in communication with the network 112 for receiving at least a portion of the redemption points and providing value to the user in exchange for the received redemption points. In at least one embodiment of the invention, credits may be stored in one or more user accounts on the database 114 wherein the accounts may be managed by software running on an administration server 118 in communication with the network, for example.
[0022] The various embodiments of the present invention may include a human powered generator 120 configured with the exercise equipment for generating electricity in response to use of the exercise equipment 102 by the user. Circuitry in communication with the generator 120 is configured for transmitting the electricity to a power distribution grid 122 , for example. In the illustrative embodiment, the quantified amount of exercise performed is a measure of the electricity transmitted to the power grid 122 , for example. The power generated may also be used for powering an electrical device 123 , or charging a battery 125 , for example.
[0023] Embodiments of human powered exercise devices are described in Applicant's co-pending U.S. patent application Ser. No. 12/408,422 which is incorporated herein by reference. It should be understood that exercise equipment 102 having a generator 120 , user interface 108 and/or measurement apparatus 104 according to embodiments of the present invention may be manufactured in such a configuration in the factory and sold as an integrated piece of equipment. Alternatively, it should be understood by persons having ordinary skill in the art that existing exercise equipment 102 including equipment long deployed in fitness centers and homes, for example, could be retrofitted with generators 120 , user interfaces 108 , and/or measurement apparatus 104 within the scope of the present invention.
[0024] In another embodiment which is described with reference to FIG. 2 , the present disclosure provides a method 200 for issuing reward credits. The method 200 includes the steps of receiving identification of an exercise equipment user 202 and quantifying 208 an amount of exercise performed by the user. Exercise credits are added 210 to an account identified to the user in response to the quantified amount of exercise performed by the user on the exercise equipment. Calculation of an amount of exercise credits may also be based on various bonuses and/or incentives, for example.
[0025] In the illustrative embodiment, electricity is generated 204 by the user's exertion on the exercise equipment. The electricity may be used directly for charging a battery or powering an electric device, or it may be supplied to a power distribution grid 206 . In the illustrative embodiment, the quantified amount of exercise performed for which the user receives credit is a measure of the electricity transmitted to the power distribution grid, or used for charging a battery or powering an electric device, for example.
[0026] In another embodiment of the invention which is described with reference to FIG. 3 , a method for exchanging reward credits 300 is provided. The method includes the steps of receiving a notification 302 of a number of exercise credits issued to an exercise equipment user in exchange for an amount of exercise performed by the user on the exercise equipment; and maintaining 304 a user account of exercise credits identified to the user. In the illustrative embodiment, the exercise credits are a measure of electricity generated by the user by using the equipment and transmitted to a power distribution grid. In an illustrative embodiment, an issuer account is maintained 306 for one or more issuers to keep track of an amount of exercise credits issued by particular issuers.
[0027] In the illustrative embodiment, the method includes the steps of receiving a request 308 to authorize a redemption of exercise credits by the user and confirming 310 that the user account includes sufficient exercise credits to satisfy the request. Authorization for the redemption is issued 314 in response to the confirmation step(s) 310 .
[0028] In an illustrative embodiment, an issuer account of exercise credits issued by an issuer is maintained 306 . Value is provided 316 to the issuer as a function of an amount of exercise credits issued to the user and redeemed at the redemption point. In the illustrative embodiment, a redemption point account recording exercise credits redeemed at a redemption point may also be maintained 312 . Value is provided 318 to the redemption point operator as a function of exercise credits redeemed at the redemption point. In the illustrative embodiment, value is also provided 320 to the user at the redemption point.
[0029] While the invention has been described with reference to illustrative embodiments, it will be understood by those skilled in the art that various other changes, omissions and/or additions may be made and substantial equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated any use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another.
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A system and method for securely measuring and tracking exercise performed by individuals and energy generated by human powered devices is provided. An amount of exercise and/or energy generated is quantified and converted to reward points usable in a rewards incentive program. Exercise performed and/or energy generated on exercise equipment is measured by measurement apparatus on the equipment. Reward points are issued locally to a user's portable stored value device or card, or may be accumulated on a remotely administered user account. A user interface disposed locally with the exercise equipment receives a user identification and provides credits to the user's stored value device or card, or provides notification to the user of credits being provided to the remote user account. A redemption point in communication with remote user accounts communicates over a network to verify sufficient credits and authorizes rewards to a user commensurate with available credits.
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FIELD OF THE INVENTION
[0001] The invention relates to a chip card comprising a display.
BACKGROUND OF THE INVENTION
[0002] In this context, a chip card is any pocket-sized card with an embedded integrated circuit that comprises hardware logic, a memory or a microcontroller/microprocessor which can process information. Chip cards can be categorized in accordance with different criteria. Particularly, chip cards can be categorized as memory-chip cards that comprise a relatively simple logic and as processor-chip cards that comprise, for instance, an operation system. Particularly processor-chip cards can receive an input signal which is processed, by way of an integrated circuit application, and deliver an output signal. Generally, chip cards can be contactless or contact chip cards, or can be a combination of both.
[0003] Contact chip cards may include a contact module on their fronts. This contact module may be gold plated and has a size of approximately 1 cm by 1 cm and may contain a chip at the back. The contact chip card may communicate with a reader. When inserted into the reader, electrical connectors of the reader contact the contact module for reading information from and writing information back to the chip card. Since normally the chip card does not include a battery, energy is supplied to the contact chip card by the reader. Contact chip cards are, for instance, standardized by ISO/IEC 7816 or ISO/IEC 7810.
[0004] In a contactless chip card, the integrated circuit communicates with the reader in a contactless manner, for instance through Radio-frequency identification (RFID). Contactless chip cards are, for instance, standardized by ISO/IEC 14443 or ISO 15693. Contactless chip cards are also known as transponders which may or may not include an active energy source, such as a battery. Transponders not having a battery are also known as passive transponders and transponders comprising a battery are known as active transponders.
[0005] International application for patent No. 94/20929 discloses a chip card that comprises an electronic data memory, an interface means connected to the data memory, to allow access to a reader, and a data display operable to display information indicative of the contents of the data memory.
[0006] Chip cards may be used, inter alia, as banking cards, transportation ticketing, loyalty cards, or e-passports. Because of this, a relatively high security level against fraudulent tampering of the card must be assured. Even though the data display may be meant to decrease danger of fraud and tempering of the usage of the chip card, the data display as an additional component potentially allows additional methods for fraud and tempering. Additionally, the display potentially increases power consumption.
OBJECT AND SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to provide a chip card comprising a display, which potentially uses less electric energy and whose security level against fraudulent misuse is increased.
[0008] The object is achieved in accordance with the invention by means of a chip card comprising a chip card controller, a display, a timing device configured to wake up at least parts of the chip card, and a display driver operatively coupled to the chip card controller and to the display, and being configured to drive the display.
[0009] The inventive chip card comprises the display that may, for instance, be an electrophoretic display, an electrochrome display, or a Liquid crystal based display. In order to drive the display, the chip card needs the display driver. A display driver may be a demultiplexer at the direct contact of the display. A display driver may also or alternatively determine which voltage should be where on the display. This functionality may also be referred to as display controller. Furthermore, the inventive chip card comprises the timing device, for instance, a timer or a clock, particularly a real-time clock, which is configured to wake up at least parts of the inventive chip card. The timing device may particularly be an integral part of the display driver. This may be achieved by forming the display driver as a single integrated circuit which includes the timing device.
[0010] The timing device is configured to wake up at least parts of the inventive chip card. Thus, the timing device is configured to wake up the entire chip card or only one or some of its components, such as its chip card controller or its display driver.
[0011] The timing device can be used for several purposes. The timing device may be configured to generate a signal at pre-defined time instances, periodically, or after a pre-defined time period after an internal action of the chip card, or at a certain time/date as it is possible with a real time clock. The signal is then used for waking up the desired parts of the chip card. Particularly, when the timing device is the real time clock, an alarm function of the real time clock could be used as a signal for waking up the chip card or at least parts of the chip card.
[0012] The signal generated by the timing device may, for instance, be used to periodically wake up the entire inventive chip card or parts thereof, particularly its chip card controller, or to wake up the chip card or parts thereof at pre-defined time instances. The timing device may also be used to wake up the chip card or parts thereof after a pre-defined time period after a certain action of the chip card. The timing device may particularly be used to initiate clearing and/or resetting the display after a pre-defined time period. Then, the part of the chip card to be woken up is the display. This may be achieved by waking up the chip controller which then can send a signal to the display driver to clear and/or reset the display. The timing device can also be configured to control directly the display driver to reset and/or clear the display. This embodiment of the inventive chip card is particularly advantageous if the display is a bistable display which continues displaying its content without a power source.
[0013] In one embodiment of the inventive chip card, this integrated circuit includes the timing device, but not the chip card controller. This embodiment results in a relatively high level of integration of the inventive chip card, potentially decreasing production cost. On the other hand, the separation of the chip card controller and the display driver potentially increases the level of security. A full integration of most or all components, especially an integration of the chip card controller and the display driver including the timing device into a single integrated circuit results in an increased number of outputs, potentially alleviating eavesdropping of the entire chip card.
[0014] In one embodiment, the inventive chip card further comprises access to at least one electric power source operatively coupled to the timing device and/or to the display device, wherein the display driver further comprises, as an integral part, a power management functionality configured to manage electric power that is available from the at least one power source for at least the timing device. In this embodiment, the inventive chip card includes power management capability particularly intended to reduce power consumption of the chip card. The power management functionality is also an integral part of the display driver. This may particularly be achieved by integrating the power management functionality into the single integrated circuit that may form the display driver. While the timing device is running, the power for the remaining parts of the chip card, besides the power management functionality or at least a wake-up circuit of the power management functionality, might be turned off.
[0015] The power management functionality is configured to manage at least the electric power for the display driver, i.e. the display driver is configured to perform its own power management. In one embodiment of the inventive chip card, the power management functionality is also responsible to carry out the power management for the chip card controller. This potentially reduces further electric power consumption of the inventive chip card.
[0016] The power management functionality may particularly be configured to turn off power for the chip card controller while the display writes information to the display and/or displays display information. Then, the chip card controller, which may be, for instance, a microprocessor or a microcontroller, is only powered when absolutely necessary.
[0017] The inventive chip card may particularly be configured to communicate with an external reader utilizing its chip card controller. Then, the inventive chip card comprises at least one appropriate communication interface. The inventive chip card may communicate with the reader contactlessly or in a contactbound manner, and thus may include a contactless communication interface or a contact interface. The contact communication interface may be in accordance with ISO 7816 and the contactless communication interface may comprise an antenna and may be in accordance with ISO 14443. It is also possible that the inventive chip card comprises both, a contact communication interface and a contactless communication interface.
[0018] When communicating with the reader, the inventive chip card may be powered via the appropriate communication interface. Thus, the power source of the inventive chip card may be formed by a communication interface. The power source, however, may also be a battery which may be non-chargeable or be chargeable utilizing, for instance, power from the communication interface.
[0019] If the inventive chip card comprises access to at least two different power sources, then the power management functionality may be configured to select one of the power sources in accordance with availability of the power sources and/or in accordance with pre-defined criteria. For instance, the power management functionality may be configured to select, if the chip card is activated, only the battery as the power source for the chip card if no power is available via the communication interface. It is also possible to switch from the battery as the power source for the chip card to the communication interface as the power source for the chip card if power becomes available via the communication interface. This enhances the lifetime of the battery.
[0020] If the inventive chip card comprises the contact communication interface, then the power management functionality of the display driver may be configured to select the contact communication interface as the preferred power source for the chip card. When including the contact communication interface, then power is delivered to the chip card from the reader in a contactbound manner. This results in a relatively strong power source potentially enhancing reliable power delivery to the inventive chip card.
[0021] The power management functionality, when applied, is integrated into the display driver which may be formed as the single integrated circuit. In one embodiment of the inventive chip card, this integrated circuit includes the timing device and, if equipped with the power management functionality, also the power management functionality, but not the chip card controller. This embodiment results in a relatively high level of integration of the inventive chip card, potentially decreasing production cost. On the other hand, the separation of the chip card controller and the display driver potentially increases the level of security. A full integration of most or all components, especially an integration of the chip card controller and the display driver including the timing device and the power management functionality into a single integrated circuit results in an increased number of outputs, potentially alleviating eavesdropping of the entire chip card. Additionally, since according to this embodiment, the chip card controller and the display driver are not integrated into a single integrated circuit, the power management functionality, if included into the inventive chip card, can relatively easily shut off the chip card controller while still activating the display driver. This results in a further improved power management, because updating the display by the display driver may take a relatively long time and support by the chip card controller is not needed during this time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention will be described in greater detail hereinafter, by way of non-limiting examples, with reference to the embodiments shown in the drawings.
[0023] FIG. 1 is a chip card comprising a display;
[0024] FIG. 2 is a flow chart illustrating a power strategy of the chip card; and
[0025] FIG. 3 is a flow chart illustrating a power takeover strategy of the chip card.
DESCRIPTION OF EMBODIMENTS
[0026] FIG. 1 shows a chip card 1 comprising a substrate 2 , a microcontroller 3 , a memory 4 , a display driver 5 , and a display 6 operatively coupled to the display driver 5 . The display driver 5 and the memory 4 are operatively coupled to the microcontroller 3 , and the microcontroller 3 , the memory 4 , the display driver 5 , and the display 6 are embedded in the substrate 2 . The memory 4 may be an EEPROM, the substrate 2 may be made from plastics, and the display 6 may be an electrophoretic display.
[0027] For the exemplary embodiment, the chip card 1 comprises a contact communication interface 7 and a contactless communication interface 8 , each operatively coupled to the microcontroller 3 and to the display driver 5 . The communication interfaces 7 , 8 are embedded in the substrate 2 . The contact communication interface 7 may be, for instance, in accordance with ISO 7816 and the contactless communication interface 8 , which may comprise an antenna, may be, for instance, in accordance with ISO 14443. Utilizing its communication interfaces 7 , 8 , the chip card 1 can communicate with a reader 9 that comprises an appropriate communication interface not explicitly shown in the figures.
[0028] If the reader 9 comprises a contact communication interface, then the chip card 1 may be inserted into the reader 9 such that the contact communication interface of the reader 9 contacts the contact communication interface 7 of the chip card 1 in a manner per se known in the art. Then, communication between the reader 9 and the chip card 1 can be carried out via the contact communication interface 7 . Furthermore, electric energy for the chip card 1 can also be supplied via the contact communication interface 7 .
[0029] If the reader 9 comprises a contactless communication interface, then the reader 9 can communicate contactlessly with the chip card 1 utilizing the contactless communication interface 8 . Communication may then be carried out utilizing Radio Frequency Identification (RFID) per se known in the art. The chip card 1 may then be powered utilizing the field emitted by the reader 9 .
[0030] For the exemplary embodiment, the chip card 1 further comprises a battery 10 embedded in the substrate 2 . The battery 10 is an example of an active power source and may be a chargeable or a non-chargeable battery. Therefore, the chip card 1 may be powered by the battery 10 or via the communication interfaces 7 , 8 .
[0031] For the exemplary embodiment, the display driver 5 is formed by a single integrated circuit that does not include the microcontroller 3 , the memory 4 , and the communication interfaces 7 , 8 . Furthermore, the chip card 1 comprises power management functionality integrated into the integrated circuit forming the display driver 5 . The power management functionality is indicated by a power management unit 11 in FIG. 1 . Besides the communication interfaces 7 , 8 , the battery 10 is operatively coupled to the display driver 5 such that its power management unit 11 can perform power management of the chip card 1 as will be explained below.
[0032] The display 6 is intended to display information stored or calculated by microcontroller 3 , for instance, in the memory 4 . The microcontroller 3 controls the display driver 5 such that it drives appropriately the display 6 .
[0033] For the exemplary embodiment, the chip card 1 , i.e. its components can be powered by three different power sources, namely the battery 10 , or via the communication interfaces 7 , 8 when communicating with the reader 9 . The purpose of the power management unit 11 is, inter alia, to choose the appropriate power source.
[0034] If the reader 9 is a contact reader, then the chip card 1 may be inserted into the reader 9 such that the contact communication interfaces 7 of the reader 9 and the chip card 1 make contact. Then, not only communication between the reader 9 and the chip card 1 is carried out via the contact communication interface 7 , but also electric power is delivered via the contact communication interface 7 to the chip card 1 . If operated in this mode, the system, i.e. the display driver 5 including its power management unit 11 and the microcontroller 3 wake up upon detecting an electric supply voltage at the contact communication interface 7 . For the exemplary embodiment, the electric power is fed directly from the contact communication interface 7 to the microcontroller 3 and to the display driver 5 .
[0035] If the reader 9 is a contactless reader, then the chip card 1 communicates with the reader 9 via its contactless communication interface 8 when the chip card 1 is in the vicinity of the reader 9 . The reader 9 emits a field which powers the chip card 1 . For the exemplary embodiment, the electric power is fed directly from the contactless interface 8 to the microcontroller 3 and to the display driver 5 including its power management unit 11 .
[0036] The chip card 1 further comprises a real-time clock 12 which, for the exemplary embodiment, is an integral part of the display driver 5 by being integrated into the single integrated circuit forming the display driver 5 . The real-time clock 12 may also be a separate chip. The real-time clock 12 may be programmed to generate and send a signal at pre-defined time instances, periodically, or after a pre-defined period of time the display 6 has displayed some display information or at a preprogrammed time/day, see alarm function RTC (Day-time, week, . . . ). The signal generated by the real-time clock 12 may be used to wake-up the microcontroller 3 and/or the display driver 5 , to display some display information on the display 6 , or to clear and/or reset the display 6 after the pre-defined time period. When being configured to clear and/or reset the display 6 after the pre-defined time period, the chip card 1 can be configured such that the real time clock 12 wakes up the microcontroller 3 such that the microcontroller 3 can control the display driver 5 in order to clear and/or reset the display 6 . The real time clock 12 can also be configured to only wake up the display driver 5 to clear and/or reset the display 6 without waking up the microcontroller 3 .
[0037] For the exemplary embodiment it is possible that even though the chip card 1 is not in contact with the reader 9 the display 6 is turned on by the real-time clock 12 . For the exemplary embodiment, the power management unit 11 then wakes up the display driver 5 in response to the signal of the real-time clock 12 . Then, the display driver 5 wakes up the microcontroller 3 by powering it utilizing the battery 10 and utilizing its power management functionality. If the voltage level of the battery 10 is too high for the microcontroller 3 , then the display driver 5 may include a voltage converter configured to down convert the battery voltage to a level suitable for the microcontroller 3 . The voltage converter may be integrated into the single integrated circuit that forms the display driver 5 or to save power at the microcontroller 3 . The voltage converter may also be used if the voltage available at the communication interfaces 7 , 8 are too high for the microcontroller 3 .
[0038] Upon receiving electric power, the microcontroller 3 retrieves display information stored in the memory 4 and sends the retrieved display information to the display driver 5 . The microcontroller 3 may also or alternatively perform a mathematical operation on the data before sending it to the display driver 5 . The display driver 5 then writes the display information to the display 6 for displaying. Furthermore, after having sent the display information to the display driver 5 , the microcontroller 3 sends a signal to the display driver 5 to turn off the power supply for the microcontroller 3 . After having written the display information to the display 6 , the display driver 5 shuts off automatically. Furthermore, after having displayed the display information for the pre-defined time period, the real-time clock 12 initiates the automatic clearing of the display 12 .
[0039] For the exemplary embodiment, the power management unit 11 carries out, after being activated, the following power priority strategy if more than one power source is available for the chip card 1 . The power strategy is summarized in FIG. 2 .
[0040] If more than one power source is available, then the power management unit 11 selects the strongest power source for powering the chip card 1 , particularly the microcontroller 3 , the display driver 5 , and the real-time clock 12 . Should power be available via the contact communication interface 7 , then the power management unit 11 always selects this power source such that the chip card 1 , i.e. its microcontroller 3 and the display driver 5 are powered via the contact communication interface 7 .
[0041] If no power is available via the contact communication interface 7 , then the power management unit 11 checks if power for the microcontroller 3 and the display driver 5 is available via the contactless communication interface 8 . If this is the case, then the power management unit 11 selects the contactless communication interface 8 to power the chip card 1 .
[0042] If power is neither available via the contactless communication interface 8 nor via the contact communication interface 8 , then the power management unit 11 selects the battery 10 to power the chip card 1 .
[0043] Additionally, the chip card 1 is configured to power the real-time clock 12 by the battery 10 as long as no power is available via the communication interfaces 7 , 8 .
[0044] During operation of the chip card 1 it may happen that the power source currently used is lost or that a stronger power source than currently used becomes available. For the exemplary embodiment, the power management unit 11 further implements the following power takeover strategy which is summarized in FIG. 3 :
[0045] A) Assuming, the chip card 1 is initially powered via the contact communication interface 7 and power is lost via the contact communication interface 7 , but power is available via the contactless communication interface 8 . If information to be displayed on the display 6 has been completely received from the reader 9 , then this information is displayed utilizing the display 6 and the display driver 5 is powered via the contactless interface 8 , otherwise the chip card 1 is shut off. This is indicated by an arrow 31 in FIG. 3 .
[0046] B) Assuming, the chip card 1 is initially powered via the contactless communication interface 8 and power is lost via the contactless communication interface 8 . If information to be displayed on the display 6 has been completely received from the reader 9 , then this information is displayed utilizing the display 6 and the display driver 5 is powered by the battery 10 , otherwise the chip card 1 is shut off. This is indicated by an arrow 32 in FIG. 3 .
[0047] C) Assuming, the chip card 1 is initially powered via the contact communication interface 7 , power is lost via the contact communication interface 7 , and no power is available via the contactless communication interface 8 . If information to be displayed on the display 6 has been completely received from the reader 9 , then this information is displayed utilizing the display 6 and the display driver 5 is powered by the battery 10 , otherwise the chip card 1 is shut off. This is indicated by an arrow 33 in FIG. 3 .
[0048] D) Assuming, the chip card 1 is currently powered by the battery 10 . If power becomes available via the contactless communication interface 8 , then the power management unit 11 selects that the chip card 1 is powered via the contactless communication interface 8 . This is indicated by an arrow 34 in FIG. 3 .
[0049] E) Assuming, the chip card 1 is currently powered via the contactless communication interface 8 and power becomes available via the contact communication interface 7 . Then, the reader 9 will reset the microcontroller 3 via the contact communication interface 7 and the chip card 1 will be powered by the contact communication interface 7 . This is indicated by an arrow 35 in FIG. 3 .
[0050] F) Assuming, the chip card 1 is currently powered by the battery 10 . If power becomes available via the contact communication interface 7 , then the power management unit 11 selects that the chip card 1 is powered via the contact communication interface 7 . This is indicated by an arrow 36 in FIG. 3 .
[0051] The reader 9 will reset the microcontroller 3 , but the display driver 5 will continue to operate using the contact power source. This is useful, because updating the display 6 by the display driver 5 may take a relatively long time and support by the microcontroller 3 is not needed during this time.
[0052] The chip card 1 described above comprises the two communication interfaces 7 , 8 . This is not absolutely necessary. The chip card 1 can also comprise only one of the communication interfaces. Furthermore, the chip card 1 does not necessarily need the battery 10 . Additionally, the button 12 and the button interface 13 , generally an input device with associated input interface are optional.
[0053] Instead of the real-time clock 12 the chip card 1 can comprise a timer which is an integral part of the driver display 5 by being integrated into the single integrated circuit forming the display driver 5 . This timer may particularly be configured to generate and send a signal after a pre-defined period of time after having been activated. This signal may be used to trigger a desired action of the chip card 1 , such as clearing the display 6 .
[0054] Finally, it should be noted that the aforementioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be capable of designing many alternative embodiments without departing from the scope of the invention as defined by the appended claims. In the claims, any reference signs placed in parentheses shall not be construed as limiting the claims. The word “comprising” and “comprises”, and the like, does not exclude the presence of elements or steps other than those listed in any claim or the specification as a whole. The singular reference of an element does not exclude the plural reference of such elements and vice-versa. In a device claim enumerating several means, several of these means may be embodied by one and the same item of software or 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 chip card ( 1 ) comprises a chip card controller ( 3 ), a display ( 6 ), a timing device ( 12 ), and a display driver ( 5 ) operatively coupled to the chip card controller ( 3 ) and to the display ( 6 ). The display driver ( 5 ) is configured to drive the display ( 6 ). The chip card ( 1 ) comprises a timing device ( 12 ) that is configured to wake up at least parts of the chip card ( 1 ).
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TECHNICAL FIELD
[0001] The present invention relates to a combustion apparatus for combusting and treating dry distillation gas generated during a waste treatment by means of dry distillation.
BACKGROUND ART
[0002] A waste treatment system comprising a combustion apparatus for treating waste by means of dry distillation in a pyrolysis furnace, with which dry distillation gas generated during the waste treatment is burnt for detoxification and resultant heat is extracted for recycling, is disclosed in patent document 1 filed by the applicant of the present application. (Japanese published patent application No.2001-108210)
[0003] The waste treatment system disclosed in said patent document comprises a pyrolysis furnace, an inert gas generator, and a generated gas treatment device. Dry distillation residue caused by the dry distillation treatment of waste in the pyrolysis furnace is transferred to the inert gas generator and inert gas generated from the dry distillation residue is returned to the pyrolysis furnace. The dry distillation gas generated during the waste treatment by means of the dry distillation is burnt in the generated gas treatment device to be extracted as heat for recycling, or if the generated gas is high in heat quantity, to be reformed and recovered as oil.
[0004] The dry distillation gas is less susceptible to dust contamination than combustion gas generated by incineration of waste, and thus it is beneficial in that combustion atmosphere can be maintained at high temperature while at the same time a level of exhaust gas can be kept low. The waste treatment by means of dry distillation is thus more advantageous than ordinary incineration treatment in the areas of exhaust gas detoxification and thermal recycling.
[0005] This type of waste treatment apparatus is required to be equipped with a means of preventing a fire and an explosion.
[0006] Conventionally, multiple nozzles with small diameter are bundled to act as a porous nozzle and used for burning the dry distillation gas. Combustion air is infused from the circumference space of each nozzle into the combustion chamber so that it mixes with the dry distillation gas and increases combustion temperature. With this arrangement, backfiring can be prevented by using the nozzles with small diameter.
[0007] Disadvantageously, however, the dry distillation gas can still get contaminated with a small amount of dust resulting from treating various types of waste and such dust would problematically block feed openings. It is ineffectual to simply enlarge the apertures of the porous nozzle in order to solve this problem, since it would cause backfiring that would blow back through the feed openings to the pyrolysis furnace and set off an explosion.
[0008] Also disadvantageously, a flow volume and a flow rate of the dry distillation gas may change at intake openings and the feed openings where a flow channel of the dry distillation gas varies in width and direction, thus the dust contained in the dry distillation gas would become solated and remain on the wall.
[0009] The solated material accumulated over an extended time period of continuous running of the apparatus becomes solid as time progresses, making it difficult to be removed. This can result in defects such as blocking of the feed openings, which consequently causes turbulent flow of the dry distillation gas to be supplied to the combustion chamber.
[0010] Still disadvantageously, an amount of the dry distillation gas to be supplied to the combustion chamber widely fluctuates, because of irregular generation of the dry distillation gas as a result of treating a mixture of various wastes. The flow rate of the dry distillation gas thus becomes turbulent, which could result in backfiring.
SUMMARY OF THE INVENTION
[0011] The present invention intends to provide an improved combustion apparatus with a low risk of a fire and an explosion, in which a nozzle is prevented from being blocked with dust contained in dry distillation gas so that backfiring would not be caused.
[0012] In order to achieve this objective, a combustion apparatus for treating dry distillation gas as defined in claim 1 comprises: a gas pipe for supplying a combustion chamber with dry distillation gas generated during a waste treatment by means of dry distillation; an air pipe for supplying a front edge of said gas pipe with combustion air; and a combustion nozzle formed at said front edge of said gas pipe; wherein, said air pipe is centrally placed inside said gas pipe so as to construct a coaxial double pipe, and said combustion nozzle is formed as a circular combustion nozzle at said front edge of said gas pipe.
[0013] In the combustion apparatus for treating dry distillation gas as defined in claim 2 , said air pipe is supported to be axially rotatable, and scrapers are further provided with blades of said scrapers being in contact with a circumference surface of said air pipe.
[0014] In the combustion apparatus for treating dry distillation gas as defined in claim 3 , an inner circumferential surface of said front edge of said gas pipe is beveled inward at predetermined angle to form a narrowed portion, and said air pipe is supported to be movable back-and-forth relative to said narrowed portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a side view of a combustion apparatus for treating dry distillation gas according to the present invention.
[0016] FIG. 2 is a partially sectional plain view of the combustion apparatus for treating dry distillation gas according to the present invention.
[0017] FIG. 3 is a sectional view of FIG. 2 along the line F-F.
[0018] FIG. 4 is a sectional view of FIG. 2 along the line A-A.
[0019] FIG. 5 is a sectional view of FIG. 2 along the line C-C.
[0020] FIG. 6 is a sectional view of FIG. 5 along the line B-B.
[0021] FIG. 7 is a sectional view of FIG. 2 along the line D-D.
[0022] FIG. 8 is a partially enlarged view of FIG. 2 .
[0023] FIG. 9 is a side view of a back-and-forth shifting apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] The present invention would be better understood when explained with references to the attached drawings. FIG. 1 is a side view of a combustion apparatus for treating dry distillation gas 1 according to the present invention, and FIG. 2 is a partially sectional plain view of the combustion apparatus for treating dry distillation gas 1 .
[0025] The combustion apparatus for treating dry distillation gas 1 consists of a gas feeding unit 3 and an air feeding unit 4 with an air pipe 5 running through both the feeding units.
[0026] The gas feeding unit 3 is comprised of a gas pipe 30 and a gas feeding tower 31 . The air pipe 5 is placed inside the gas pipe 30 in order to form a coaxial double pipe, which is inserted into a combustion chamber 20 to form a combustion nozzle.
[0027] The air feeding unit 4 comprises an outer cylinder 40 , to which an air feeding tower 43 is jointed. The air feeding unit 4 is located so as that it shields air feeding apertures 50 made on the air pipe 5 .
[0028] A fixed base 10 and a movable base 11 facing each other are placed underneath the rear section of the air pipe 5 . The movable base 11 is sidably connected to the fixed base 10 via a back-and-forth shifting apparatus 6 .
[0029] A support frame 12 and a set of four support rollers 13 are provided at each end of the movable base 11 . As shown in FIG. 3 , the rotatable support rollers 13 mounted on the support frame 12 hold a roller guide 14 that is provided on the air pipe 5 .
[0030] FIG. 4 further shows a motor 15 mounted on the movable base 11 and a guide 51 provided around the air pipe 5 , between which a transmission means 16 such as a heat-proof belt is rolled over to allow the air pipe 5 to rotate.
[0031] FIG. 5 is a sectional view of the gas feeding unit 3 along the line C-C and FIG. 6 is a sectional view of the gas feeding tower 31 along the line B-B.
[0032] The gas feeding unit 3 is constructed with the gas feeding tower 31 being jointed on the circumference of the gas pipe 30 . The gas pipe 30 is inserted into a nozzle inserting port 21 of a combustion furnace 2 . A circular gap A is formed between the gas pipe 30 and the air pipe 5 coaxially placed in the gas pipe 30 .
[0033] Dry distillation gas is supplied from the gas feeding tower 31 and runs through a cylindrical gap between the gas pipe 30 and the air pipe 5 to be finally infused into the combustion chamber 20 from the circular gap A at the front edge of the gas pipe 30 .
[0034] A risk of backfiring can be decreased by elongating a distance between the gas feeding tower 31 and the front edge of the gas pipe 30 , since the dry distillation gas infused from the circular gap A would be more stable as said distance gets longer than it is actually required depending on gas density or flow resistance rate.
[0035] Finders 35 are mounted on the circumference of the gas pipe 30 with an angle relative to a tangent for the purpose of viewing a state of dust adhering. The gas feeding tower 31 is also provided with the finders 35 . The finders 35 may be equipped with cleaning nozzles for cleaning a pipe wall in the dry distillation gas atmosphere.
[0036] A pair of scrapers 33 is supported by a supporting member 32 built in the gas feeding tower 31 and blades of the scrapers 33 are in contact with the circumference of the air pipe 5 . The scrapers 33 are positioned so as that they are double-tiered but without having scraping areas overlap each other. As the air pipe 5 rotates, the dust accumulated on the circumference of the air pipe 5 can be scraped off.
[0037] A tank B equipped with a seal damper 34 is located on the lower side of the gas feeding tower 31 . In an embodiment illustrated in FIGS. 5 and 6 , a sliding seal damper 34 is used for sealing the tank B from the gas feeding tower 31 that is under the dry distillation gas atmosphere. The tank B is further provided with a vent. As the tank B can be sealed off with the seal damper 34 , scraped dust pieces in the tank B can be regularly taken out from the vent even when the combustion chamber is running. The seal damper 34 can take forms other than sliding type, such as a butterfly type.
[0038] FIG. 7 is a sectional view of the air feeding unit 4 along the line D-D. The air feeding unit 4 comprises the outer cylinder 40 and the air feeding tower 43 . The outer cylinder 40 is sectioned into an upper outer cylinder 41 and a lower outer cylinder 42 , and the air feeding tower 43 is integrally connected to the lower outer cylinder 42 . The air pipe 5 has the air feeding apertures 50 , which are dividing the circumference of the air pipe 5 into 5 segments in the embodiment of FIG. 5 . The upper outer cylinder 41 and the lower outer cylinder 42 are jointed together to cover said air feeding apertures 50 .
[0039] Combustion air is supplied from the air feeding tower 43 and passes through the air feeding apertures 50 to enter into the air pipe 5 . The combustion air then runs through the air pipe 5 and is eventually delivered into the combustion chamber 20 via an air feeding port 52 .
[0040] The combustion air and the dry distillation gas are thus blended to be burnt together, and generate an inert gas such as carbon dioxide.
[0041] FIG. 8 is a partially sectional plain view of a nozzle.
[0042] The aforesaid gas pipe has its front inner circumference beveled inward to form a narrowed portion. In the illustrated embodiment, a corner of the combustion chamber at the nozzle inserting inlet 21 is alternatively formed with an angle α, but the gas pipe 30 may instead be formed with an angle at its front edge to form the narrowed portion. The air pipe 5 also has its front edge beveled inward with an angle β, which is smaller than the angle α. The opening width of the circular gap A can be adjusted by these angles α and β together with the back-and-forth shifting apparatus 6 , whose details will be explained later.
[0043] In the gas feeding unit 3 , a packing stopper 36 is provided on the inner wall of the gas pipe 30 . A packing 38 is impregnated with a substance such as carbon so that it achieves heat resistance along with decay resistance, and is fitted into the circular gap A. The packing 38 is then pressed with a presser flange to be bonded by pressure.
[0044] Also in the air feeding unit 4 , the packing 38 is used for sealing a jointed region of the upper outer cylinder 41 and the lower outer cylinder 42 as well as a contact site of the air pipe 5 and the outer cylinder 40 so as to form a so called “swivel” structure.
[0045] The dry distillation gas and the combustion air would not only contain toxic components, but also they could reach a very high temperature. It is therefore necessary that areas being under the dry distillation gas atmosphere or the combustion air atmosphere be blocked from outside air by means such as the packing 38 . The dry distillation gas and the combustion air in fact reach a few hundreds degrees C. in temperature, and thus the belt used as the transmission means 16 and the packing 38 need to be provided with sufficient heat resistance and decay resistance.
[0046] FIG. 9 is a side view of the back-and-forth shifting apparatus 6 .
[0047] The back-and-forth shifting apparatus 6 has a handled screw shaft 60 . The movable base 11 can be moved back-and-forth relative to the fixed base by turning the handled screw shaft 60 . This back-and-forth movement is transmitted via the support rollers 13 and shifts the air pipe 5 back-and-forth as well, thereby adjusting the opening width of the circular combustion nozzle.
[0048] The present invention constructed as described above will operate as follows.
[0049] The dry distillation gas is supplied from the gas feeding unit 3 and runs through a cylindrical gap between the gas pipe 30 and the air pipe 5 to be finally infused into the combustion chamber 20 from the circular gap A at the front edge of the gas pipe 30 .
[0050] The combustion air is supplied from the air feeding tower 43 and passes through the air feeding apertures 50 to enter into the air pipe 5 . The combustion air then runs through the air pipe 5 and is eventually delivered into the combustion chamber 20 via an air feeding port 52 , where the combustion air and the dry distillation gas are blended and burnt together.
[0051] The amount of the dry distillation gas to be generated would largely fluctuate depending on types and conditions of waste, but the amount of the dry distillation gas to be supplied can be stabilized by adjusting the width of the circular gap A with the aid of the angle α and β given at the front edge of the gas pipe 30 together with the back-and-forth shifting apparatus 6 .
[0052] The finders 35 are mounted on the circumference of the gas pipe 30 , enabling viewing of the pipe wall to which the dust contained in the dry distillation gas would adhere. The finders 35 may be equipped with the cleaning nozzles so that the pipe wall under the dry distillation gas atmosphere can be cleaned when the combustion apparatus is not in operation. At the same time, however, the present invention is arranged with the scrapers 33 being in contact with the circumference of the air pipe 5 that is rotatably supported by way of the support rollers 13 mounted on the movable base 11 , the motor 15 , and the transmission means 16 , and therefore the dust accumulated on the pipe wall of the air pipe 5 can be scrapped off even while the dry distillation treatment is being operated.
[0053] The dust so scraped from the pipe wall are dropped in the tank B that is located on the lower side of the gas feeding tower 31 , and can be regularly or continuously taken out therefrom.
[0054] The combustion air as previously described may be replaced by high-temperature steam. When the dry distillation gas is exposed to the high-temperature steam, it becomes separated and generates inert gas such as carbon dioxide, thereby producing the identical effects of the combustion air. Even advantageously, the volume of the gas to be finally exhausted can be significantly reduced, since the high-temperature steam does not contain nitrogen.
INDUSTRIAL APPLICABILITY
[0055] As defined in claim 1 , the present invention is constructed in a double pipe structure so that it forms the circular combustion nozzle, thereby achieving the feed opening for the dry distillation gas with sufficient width. With this arrangement, a large amount of the dry distillation gas can be evenly supplied and a blockage of the feed opening with dust pieces can be prevented, thereby lowering a danger of backfiring.
[0056] As defined in claim 2 , the present invention is constructed with the rotatable air pipe and the scrapers, with which the dust accumulated on the pipe wall can be scraped off while the apparatus is continuously being in operation. With this arrangement, the dry distillation gas can be stably supplied from the feed opening without any turbulence, thereby preventing backfiring.
[0057] As defined in claim 3 , the present invention is constructed with the air pipe that is movable back-and-forth so that the width of the circular combustion nozzle can be adjusted in proportion to the amount of the generated dry distillation gas. With this arrangement, the dry distillation gas can be supplied from the feed opening at a constant flow volume and a flow rate, thereby preventing backfiring.
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The present invention intends to provide an improved combustion apparatus with a low risk of a fire and an explosion, in which a nozzle is prevented from being blocked with dust contained in dry distillation gas so that backfiring would not be caused. A combustion apparatus for treating dry distillation gas is thus constructed with a gas pipe for supplying a combustion chamber with dry distillation gas generated during a waste treatment by means of dry distillation and an air pipe for supplying a front edge of the gas pipe with combustion air, wherein the air pipe is placed inside the gas pipe to construct a coaxial double pipe so that it forms a circular combustion nozzle at the front edge of the gas pipe.
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[0001] This application is a continuation of co-pending U.S. patent application having Ser. No. 10/300,382 filed on Nov. 19, 2002. These and all other extrinsic materials discussed herein are incorporated by reference in their entirety. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
FIELD OF THE INVENTION
[0002] The field of the invention is cutting devices and apparatus, knives and utility knives.
BACKGROUND OF THE SUBJECT MATTER
[0003] Industries that utilize cutting devices and apparatus in everyday and/or routine activities, such as opening boxes and bags, cutting and sizing cardboard, rope, heavy paper, fabric, plastic bags and the like and any other activity or task that requires the use of a cutting device or apparatus requires or mandates that the cutting device or apparatus meet certain minimum safety criteria, and ultimately, wants a cutting device or apparatus that maximizes safety features for the operator, while. allowing the operator to easily perform the desired tasks with the cutting device or apparatus.
[0004] There are many reasons that industries want safer cutting devices and safer conditions for employees, including a) minimizes workplace accidents, b) minimizes lost time on the job of employees, c) acts as a possible marketing tool for the employer to potential employees, d) reduces risk from an insurance standpoint and could contribute to lower insurance premiums or additional coverage and e) reduces liability-based legal actions and arbitrations.
[0005] There have been many attempts to manufacture a safer utility knife or cutting device. U.S. Pat. No. 5,878,501 issued to Owens et al. on Mar. 9, 1999 describes one such attempt to create a safer utility knife. The Owens utility knife comprises a blade cover that shields the operator from an exposed blade edge when the utility knife is not in use. The operator exposes the cutting surface of the blade by depressing two buttons on the side of the utility knife that are connected to the blade cover. Once the buttons are depressed, they can be pulled back away from the blade, thus pulling back the blade cover and exposing the cutting surface of the blade. However, once the cutting surface of the blade is exposed, only a conscious movement by the operator of depressing the buttons and pulling them towards the cutting surface can pull the blade cover over the cutting surface of the blade protecting the operator from further exposure to the cutting surface.
[0006] In U.S. patent application Ser. No. 09/804,451 filed on Mar. 12, 2001, which is commonly assigned and is incorporated herein by reference in its entirety, Votoloto improved on the Owens utility knife by providing a blade cover that can be pulled back from the cutting surface of the blade by using a trigger lever. If the trigger lever is depressed too quickly, such as what might occur in a panic situation, an intercept member causes disengagement of the blade cover from the trigger lever, thus causing the blade cover to return to a position where the cutting surface of the blade is covered by the blade cover. While the Votolato utility knife is an advancement in safety for utility knives and cutting tools, there are still aspects of that knife that could be improved. For example, there is no automatic function that closes the blade cover over the cutting surface in non-panic-type of situations, such as completion of a cutting job.
[0007] In addition to safety requirements, companies that utilize cutting devices and apparatus also would like to see certain ergonomic, sanitary and aesthetic features incorporated into the cutting device or apparatus, as mentioned previously herein. With respect to the sanitary requirement, industries that rely on the cutting device to be sanitary are the food service, food preparation and food sales industries, along with any other industries or companies where utility knives could contact food or food preparation surfaces. Another requirement or focus would be to eliminate loose razor blade contamination of food, food stuff, food preparation areas, food processing batches, pharmaceutical batches, chemical batches and other products that are easily contaminated by loose razor blades and razor blade pieces.
[0008] Therefore, there is a need for a cutting device or apparatus that a) is safe to use by the operator, b) reduces workplace accidents and the risk of workplace accidents, c) is ergonomically safe and effective, d) is sanitary for use around and in preparing consumer products, e) is aesthetically pleasing in an environment, such that it will be regularly used, and f) eliminates or greatly minimizes contamination of consumer products by loose blades and loose blade pieces.
SUMMARY OF THE INVENTION
[0009] A cutting apparatus has been produced that eliminates the common occurrence of raw razor blades contaminating everything from food and food products to garbage cans to shelves in retail stores. Furthermore, the cutting apparatus comprises a guard assembly that, when activated, opens the blade cover and allows only one cut to be made with the exposed blade before the unidirectionally-locking blade cover snaps back over the exposed blade and locks into a closed position, thus preventing laceration-related accidents. In addition, if the operator continues to activate the guard assembly (squeezing, pulling and/or depressing the trigger and/or releasing the trigger and continuing to hold it in the released position during and after the cut has been made) after one cut has been made with the exposed blade, the unidirectionally-locking blade cover will still snap back over the exposed blade, despite the position of the trigger. Once the blade cover snaps back over the exposed blade and locks into the closed position, the locking device is activated and acts to hold the blade cover securely over the blade until the blade assembly is further activated by releasing the trigger from the depressed position and depressing or pulling the trigger once again.
[0010] As described herein, a cutting apparatus comprises a) a handle assembly; b) a guard assembly coupled to the handle assembly, wherein the guard assembly comprises a unidirectionally-locking blade cover, a trigger and a locking device; and c) a removable blade assembly coupled to the handle assembly, wherein the blade assembly comprises a blade guard, a blade and a holder apparatus.
[0011] Also as described herein, a method of using a safety cutting apparatus comprises a) providing a surface; b) providing the safety cutting apparatus described herein; c) releasing the trigger; d) applying the blade to the surface; and e) cutting the surface, wherein cutting comprises making only one continuous cut in the surface.
BRIEF DESCRIPTION OF THE FIGURES
[0012] FIG. 1A-1B are contemplated embodiments of the safety cutting apparatus.
[0013] FIG. 2 shows a contemplated embodiment of the safety cutting apparatus.
[0014] FIG. 3A-3C shows contemplated embodiments of the safety cutting apparatus.
[0015] FIG. 4A-4B shows contemplated embodiments of the blade assembly.
[0016] FIG. 5A-5B shows contemplated embodiments of the blade assembly.
DETAILED DESCRIPTION
[0017] A cutting apparatus has been produced that eliminates the common occurrence of raw razor blades contaminating everything from food and food products to garbage cans to shelves in retail stores. Furthermore, the cutting apparatus comprises a guard assembly that, when activated, opens the blade cover and allows only one cut to be made with the exposed blade before the unidirectionally-locking blade cover snaps back over the exposed blade and locks into place, thus preventing laceration-related accidents. In addition, if the operator continues to activate the guard assembly after one cut has been made with the exposed blade, the unidirectionally-locking blade cover will still snap back and lock into place over the exposed blade, despite the position of the trigger. As used herein, the phrase “if the operator continues to activate” means that if the operator is releasing, squeezing, depressing and/or pulling the trigger or releasing the trigger and continuing to hold it in the released position during and after the cut has been made, the unidirectionally-locking blade cover will still snap back and lock into place over the exposed blade, despite the position of the trigger. Once the blade cover snaps back over the exposed blade, the locking device is activated and acts to hold the blade cover securely over the blade until the blade assembly is further activated by releasing the trigger from the depressed position and depressing, releasing, squeezing or pulling the trigger once again.
[0018] As described herein, a contemplated cutting apparatus 10 is shown in FIG. 1A-1B and comprises a) a handle assembly 100 ; b) a guard assembly 140 coupled to the handle assembly 100 , wherein the guard assembly 140 comprises a unidirectionally-locking blade cover 145 , a trigger 150 and a locking device 155 ; and c) a removable blade assembly 180 coupled to the handle assembly 100 , wherein the blade assembly 180 comprises a blade guard 185 , a blade 190 and a holder apparatus 195 .
[0019] The handle assembly 200 of the cutting apparatus, as shown in FIG. 2 , is designed to a) comfortably and ergonomically fit the hand of the operator for ease of use, b) couple with the blade assembly 280 and c) couple with the guard assembly 240 , where the blade cover 245 and trigger 250 are shown. The handle assembly 200 can be designed as shown to have venting openings 210 or “pass-throughs” throughout the handle allowing for the hand holding it to “breath”, thus resulting in a cooling effect on the hand holding it. The vents 210 in the handle assembly 200 also contribute to the light weight of the knife. In other contemplated embodiments, the handle assembly 200 may comprise a solid handle—i.e. without vents 210 or pass-throughs. In this case, a removable gripper cover (not shown) comprising a breathable material may cover the handle. For example, the breathable material may comprise holes or pores that allow the material to stay dry during long periods of use. Furthermore, the gripper cover can be removable and either disposable or washable, so that the handle stays clean during use by several operators over a period of time or during prolonged use by one user. In these embodiments, the removable gripper cover would slip onto the distal end of the handle assembly away from the blade assembly and cover the portion of the handle assembly up to the trigger and trigger opening.
[0020] Also, as contemplated and as shown in FIGS. 3A-3C , the cutting apparatus 30 comprises a guard assembly 340 coupled to the handle assembly 300 , wherein the guard assembly 340 comprises a unidirectionally-locking blade cover 345 , a trigger 350 and a locking device 355 which comprises a pawl 356 . In some contemplated embodiments, the blade assembly 380 is covered by a movable, spring-loaded unidirectionally-locking blade cover 345 . A locking device 355 contained within the handle assembly 300 locks the blade cover 345 over the blade 390 . As mentioned, releasing by squeezing, pulling and/or depressing a trigger 350 on the exterior of the handle assembly 300 unlocks the blade cover 345 and allows only one cut to be made in a material or on a surface (not shown). This safety feature is activated by a) releasing—squeezing, pulling and/or depressing—the trigger 350 on the exterior of the handle assembly 300 , thus deactivating the locking device 355 ; b) pressing the unidirectionally-locking blade cover 345 against a surface in order to make a cut into a surface or material; and c) exposing the blade 390 by rotating the blade cover 345 back into the handle assembly 300 . The exposed is shown in FIG. 3B . Once the cut is made and the operator pulls the blade 390 out of the material or surface, pressure is removed from the blade cover 345 and the blade cover 345 rotates back over the blade 390 and locks. The locked blade cover 345 over the blade 390 is shown in FIG. 3C . In order to make another cut, the trigger 350 must be released—depressed, pulled and/or squeezed again. Therefore, as used herein, the “unidirectionally-locking” blade cover 345 is defined, in that the blade cover 345 only locks in place in one direction, and that direction is when the blade cover 345 is covering the blade 390 . When the blade cover 345 is unlocked and the blade 390 is exposed, the blade cover 345 is not locked into place exposing the blade 390 , but is instead held into an open position (exposing the blade 390 ) by the pressure exerted on the blade cover 345 by the surface or material being cut.
[0021] As mentioned and as shown in FIG. 3A , the guard assembly 340 comprises three active parts—the trigger 350 , a locking device 355 which comprises a pawl 356 , and the blade cover 345 . In one contemplated embodiment, two springs and/or spring-like devices, one spring 357 for the blade cover and one spring 358 for the pawl, activate these parts (a “spring and pawl assembly”). The trigger 350 is activated via its own integral, molded spring arm 342 , which includes components 341 , 342 A and 342 B. The handle assembly 300 provides the pivots and stops 343 A, 343 B necessary for mounting and limiting the travel of the active parts and springs. The blade cover 345 and the trigger 350 pivot on the handle assembly 300 ; the pawl 356 and its spring 358 pivot on the blade cover 345 . The pawl 356 links rotary motion from the blade cover 345 to the trigger 350 . The configuration and material of the pawl 356 allow it to flex sideways and spring back even though it is rigid in all other directions. A portion of the pawl 356 rides in a looped pathway on the trigger 350 . Two ramped steps on the pathway limit the pawl's 356 travel to one direction. This forces it, once it starts along the pathway, to finish a complete loop. This one-direction travel is what allows locking of the blade cover 345 to be accomplished independent of the trigger position.
[0022] Normally, the trigger 350 rests where the pawl 356 cannot enter the pathway. Because the pawl 356 cannot enter the pathway, or move anywhere else within the handle assembly 300 , the blade cover 345 cannot move from covering the blade 390 . Releasing the trigger 350 positions the pathway where the pawl 356 can enter it, which allows the blade cover 345 to rotate, thus exposing the blade 390 when pressure is exerted on the blade cover 345 from the surface and/or material to be cut (not shown). If the trigger 350 is released at this point, before the blade cover 345 is moved at all, the blade cover 345 relocks. If however, the blade cover 345 is pressed against a surface and/or material to make a cut, the blade cover 345 is rotated into the handle assembly 300 exposing the blade 390 . As the blade cover 345 rotates, it moves the pawl 356 and causes the pawl 356 to travel along the pathway. As it does, it flexes laterally to ride up and over the ramped steps, and springs back once past the ramped steps.
[0023] After the pawl 356 travels over the first step, it cannot retrace its path and enters the return segment of the pathway. Now, when pressure is taken off the blade cover 345 , its return spring rotates it back over the blade 390 . This rotation causes the pawl 356 to continue over a second step. If the trigger 350 has already been released, the pawl 356 simply returns to the locked starting position. However, if the trigger 350 has not been released, the pawl 356 could return to the unlocked starting position. To prevent this, the pathway is configured to hold the pawl 356 against the second step, which also keeps it from retracing its path. As a result, the blade cover 345 is locked, and remains so until the trigger 350 is completely released and squeezed again.
[0024] The blade assembly 480 is shown in FIG. 4A and is completely removable from the handle assembly (not shown) and comprises a blade guard 485 , a blade 490 and a holder apparatus 495 . Furthermore, the blade assembly 480 is designed to hold only one blade 490 at a time. The blade 490 is fixedly coupled to the holder apparatus 495 , and therefore, moves only when the holder apparatus 495 moves. The blade assembly 480 is disposable in relation to the cutting apparatus (not shown) and is safe to handle by the operator prior to coupling to, during coupling to and upon removal from the handle assembly (not shown). The blade guard 485 is designed to effectively cover and lock over either the cutting surface of or the entire blade 490 until the blade assembly 480 is coupled to the handle assembly (not shown). As the blade assembly 480 is being coupled to the handle assembly, the blade guard 485 retracts from covering the cutting surface of or the entire blade 490 and locks into place by coupling with a latch 496 The latch 496 holds the blade guard 485 in place and away from the cutting surface of the blade 490 until the blade assembly 480 is removed from the handle assembly. The blade guard 485 effectively eliminates all the injuries and contamination-related issues caused from raw blade handling and also from someone reaching down into a trash receptacle and getting cut by an exposed blade. And as mentioned earlier, the herein-described blade assembly and ultimately the cutting apparatus eliminates loose razor blade contamination of food, food stuff, food preparation areas, food processing batches, pharmaceutical batches, chemical batches and other products that are easily contaminated by loose razor blades and razor blade pieces.
[0025] In some embodiments, and as shown in FIG. 4B , however, the blade assembly 480 is not removable from the handle assembly (not shown), but is instead fixed into the handle assembly, such that when the blade life expires and/or the blade 490 dulls, the entire cutting apparatus (not shown) can be disposed of by the operator. In these embodiments, the entire cutting apparatus becomes the blade assembly—meaning that the entire cutting apparatus is removable and disposable. In those embodiments where the blade assembly 480 is not removable from the handle assembly, there will not be a blade guard 485 coupled to the blade assembly 480 , since there is no assembly step or removal step of the blade assembly to and from the handle assembly.
[0026] As an example of one contemplated embodiment and as shown in FIGS. 4A and 4B , the holder apparatus 495 of the blade assembly 480 provides spring snaps that 1) latch (latch 496 ) the blade guard 485 over the blade 490 when the blade assembly 480 is out of the handle assembly (not shown), and 2) latch (latch 497 ) the blade assembly 480 into the handle assembly. The blade guard 485 incorporates an additional latch 498 that latches the shield into the handle assembly independent of the latch 497 for the handle assembly. This additional latch 498 is to insure, as described below, that the blade guard 485 recovers the blade 490 as the blade assembly 480 is being removed from the handle assembly. A stop tab on the blade guard 485 travels in a track on the holder apparatus 495 of the blade assembly 480 and prevents the blade guard 485 from being pulled off of or detached from the blade assembly 480 in part or altogether.
[0027] When the blade assembly 480 is first inserted into the handle assembly, the blade assembly 480 travels freely until stops on the blade guard 485 hit the handle assembly and latch 498 engages. As more pressure is applied to the blade assembly 480 , latch 496 is over-ridden and the holder apparatus 495 of the blade assembly 480 continues to slide into the handle assembly uncovering the blade 490 as it does. When the blade assembly 480 reaches the limit of its travel, latch 497 engages locking the blade assembly 480 into the handle assembly.
[0028] To remove the blade assembly 480 , the user operates latch 497 and pulls the holder apparatus 495 of the blade assembly 480 out of the handle assembly (not shown). Because the blade guard 485 is still latched by latch 496 , the holder apparatus 495 moves independent of the blade guard 485 , recovering the blade 490 . When the stop tab reaches the end of its travel, latch 496 re-latches and latch 498 is over-ridden allowing the entire blade assembly 480 , with the blade 490 now recovered by the blade guard 485 , to be pulled free of the handle assembly.
[0029] FIGS. 5A and 5B show another contemplated blade assembly 580 where in FIG. 5A the blade guard 585 is locked in the open position exposing the blade 590 and in FIG. 5B the blade guard 585 is covering the blade 590 in the closed position. In FIG. 5B the blade 590 is shown as dotted lines to indicate that its covered by the blade guard 585 .
[0030] In contemplated embodiments, the blade assembly will, in part or in total, be a bright florescent color to aid in finding them should the assembly be left on shelves or fall into product. In other embodiments, the blade assembly may be suitably marked with any color that will make the assembly readily visible to the naked eye when the assembly is on a shelf, in a consumer product or in a trash can. This prominent color marking or treatment results in the drastic reduction and/or elimination of the blade assemblies contaminating food, retail shelves, and other products. Prominent color marking and/or color treatment will also result in fewer injuries to consumers and the high legal and medical costs associated with those injuries.
[0031] In some contemplated embodiments, the blade may be set into the blade cartridge such that the blade is exposed at differing potential cutting depths. For example, in some instances, the blade may be exposed only a few millimeters, in order to cut thin surfaces. In other instances, the blade may be exposed at least a centimeter or more in order to cut corrugated cardboard surfaces or other thick surfaces. In these instances, the color coding of the blade cartridge may be set such that different colors indicate different blade cutting depths. For example, fluorescent green may indicate a cutting depth of 4 mm, while cherry red indicates a cutting depth of 1 cm, and so forth. In other instances, the number of stripes or dots on the blade cartridge may indicate cutting depth of the blade. For example, a fluorescent green blade cartridge with 4 bright orange dots may mean a cutting depth of 4 mm (1 mm corresponding for each dot, 1 stripe every 1 cm), while a cherry red blade cartridge with one bright yellow stripe means 1 cm cutting depth. This stripe and dot color coding will help those who are color blind or who otherwise have trouble distinguishing one color.
[0032] In a contemplated embodiment, the blade comprises metal while the remaining components of the cutting apparatus comprise an organic or inorganic-based material, such as a particular kind of plastic, composite material or other suitable material. However, it is contemplated that every component of the cutting apparatus may comprise metal, a metal-based material, an organic-based material, an inorganic-based material, an organometallic-based material, a composite material and/or a combination thereof. Materials contemplated herein may further comprise polymers and/or monomers. It is contemplated that suitable materials are those materials that can be used to form a cutting apparatus capable of cutting or slicing into a layer or layers of matter, such as paper, cardboard, plastic, metal sheeting, wood, glass, drywall and the like.
[0033] As used herein, the term “metal” means those elements that are in the d-block and f-block of the Periodic Chart of the Elements, along with those elements that have metal-like properties, such as silicon and germanium. As used herein, the phrase “d-block” means those elements that have electrons filling the 3d, 4d, 5d, and 6d orbitals surrounding the nucleus of the element. As used herein, the phrase “f-block” means those elements that have electrons filling the 4f and 5f orbitals surrounding the nucleus of the element, including the lanthanides and the actinides. Preferred metals include titanium, silicon, cobalt, copper, nickel, zinc, vanadium, aluminum, chromium, platinum, gold, silver, steel and stainless steel. More preferred metals include titanium, silicon, copper, aluminum, nickel, platinum, gold, silver and tungsten. Most preferred metals include titanium, aluminum, silicon, copper and nickel. The term “metal” also includes alloys, metal/metal composites, metal ceramic composites, metal polymer composites, as well as other metal composites.
[0034] As used herein, the term “monomer” refers to any chemical compound that is capable of forming a covalent bond with itself or a chemically different compound in a repetitive manner. The repetitive bond formation between monomers may lead to a linear, branched, super-branched, or three-dimensional product. Furthermore, monomers may themselves comprise repetitive building blocks, and when polymerized the polymers formed from such monomers are then termed “blockpolymers”. Monomers may belong to various chemical classes of molecules including organic, organometallic or inorganic molecules. The molecular weight of monomers may vary greatly between about 40 Dalton and 20000 Dalton. However, especially when monomers comprise repetitive building blocks, monomers may have even higher molecular weights. Monomers may also include additional groups, such as groups used for crosslinking.
[0035] As used herein, the term “crosslinking” refers to a process in which at least two molecules, or two portions of a long molecule, are joined together by a chemical interaction. Such interactions may occur in many different ways including formation of a covalent bond, formation of hydrogen bonds, hydrophobic, hydrophilic, ionic or electrostatic interaction. Furthermore, molecular interaction may also be characterized by an at least temporary physical connection between a molecule and itself or between two or more molecules.
[0036] Contemplated polymers may also comprise a wide range of functional or structural moieties, including aromatic systems, and halogenated groups. Furthermore, appropriate polymers may have many configurations, including a homopolymer, and a heteropolymer. Moreover, alternative polymers may have various forms, such as linear, branched, super-branched, or three-dimensional.
[0037] There are several benefits and advantages to using the cutting apparatus described herein, including but not limited to:
inexpensive to manufacture due to minimal use of material and parts built in safety mechanisms that allow for one single cut or slice into a material eliminates loose razor blades and associated medical, insurance, financial and time losses because of razor blade-related accidents minimizes many of the lacerations associated with the knives and cutting devices on the market today, especially the lacerations that result from the cutting device slipping off of the surface and into the operator's leg, arm, abdomen, etc. ergonomically sound in that the cutting apparatus is light-weight and easy to handle based on design modifications
[0043] In some additional embodiments of the cutting apparatus, the apparatus comprises a tape piercing member that is located on the distal end of the handle assembly. The tape piercing member is designed to break or pierce tape found holding box flaps or other surface areas closed on most boxed items or otherwise contained items. This tape piercing member is a safe and easy way to cut open a box without having to use the blade. The tape piercing member is also used to eliminate the damage to the contents of the box or container caused by a blade opening the box or container with the contents being cut by the blade.
[0044] Thus, several specific embodiments and applications of the cutting apparatus have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.
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A cutting apparatus has a unidirectionally-locking blade cover that automatically snaps back over the exposed blade after each cut, and a dependent, index finger operated unlocking trigger.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sewing machine and more particularly relates to a sewing machine having an indicating device which is electrically operated to indicate a plurality of selected patterns arranged to be stitched in combination.
2. Related Art
Now a sewing machine having a zigzag stitching function for forming the patterns of zigzag stitches is available in the market and is widely used. Such a sewing machine is generally provided with an indicating device for indicating the patterns selected by the user for confirmation at the time of stitching the selected patterns.
The pattern data for stitching patterns are generally formed up in consideration of the difference in efficiency of circular arc movement of machine needle and of forward and reverse movement of a work feeding mechanism. It is, therefore, unavoidable that the pattern data indicated as being in the indicating device will be different from the actually stitched result of the patterns. Therefore, the indication data for indicating patterns are generally prepared by using the bit map data for each of the patterns to be selectively stitched.
SUMMARY OF THE INVENTION
However, in the recent years, the sewing machine has come to have many functions including optional combination of patterns, optional enlargement and reduction of patterns and so on. In fact, the conventional indicating function is not sufficient for satisfying such variation of patterns to be stitched.
For example, in case the patterns are to be stitched in combination, the patterns are not indicated in a combined state, but are indicated individually. Further, in case the patterns are optionally enlarged or reduced by the user, the patterns indicated will remain as unchanged.
The invention has been provided to eliminate such defects and disadvantages of the prior art.
For attaining the object, the invention has been made in connection with a sewing machine for stitching optionally selected patterns in accordance with pattern data, and the sewing machine comprises a means for giving indication data for said pattern data, a means for arranging said indication data in accordance with a combination of said pattern data, a means for changing said indication data in accordance with the change of said pattern data, a means for indicating said indication data in a manner that said indication data may be scrolled, a means for designating an initial one of the pattern data indicated at said indicating means.
With the combination of elements, in case the patterns are optionally combined, the indication data is indicated in accordance with the combined patterns and may be changed in accordance with change of the pattern data. Such indication data as indicated will be confirmed by the machine user as being the same with the stitched result of patterns which are selected to be stitched. Further, since the means for indicating the indication data may be so formed as to scroll the indicated patterns, all of the patterns may be indicated even if a series patterns to be indicated are beyond the indication area of the indicating device. Further, with a means provided to designate the pattern data to be changed at the indication surface of the indicating means, the machine user may change the pattern data while the user is watching the indication data.
Further, according to the invention, in case the same patterns are combined linearly, the same patterns may be indicated in series while the image treatment is performed, wherein the stitch end point of indication data for the pattern data preceding the next indication data for the next pattern data is made to be a stitch start point of the next indication data for the next pattern data. Therefore, the actually indicated patterns may be substantially the same with the patterns to be actually stitched.
Further, according to the invention, in case the pattern data preceding the initial pattern data for the patterns indicated at the indicating means is the same with the initial pattern data, it is discriminated whether or not the initial pattern data overlaps the preceding pattern data. In case it is discriminated that the initial pattern data overlaps the preceding pattern data, the image treatment is started from the preceding pattern data so that the overlapped portion of pattern data may be indicated at the indicating means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing the embodiment of the invention.
FIG. 2 is an explanatory view showing the operation of the embodiment of the invention.
FIG. 3 is another explanatory view showing the operation of the embodiment of the invention.
FIG. 4 (A) is an explanatory view showing the operation of the embodiment of the invention in connection with FIG. 3 .
FIG. 4 (B) is an explanatory view showing the operation of the embodiment of the invention in connection with FIG. 4 (A).
FIG. 5 is a flow chart showing the operation of the embodiment of the invention.
FIG. 6 is a flow chart showing the operation of the embodiment of the invention in connection with FIG. 5 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will be described in reference to the attached drawings.
In FIG. 1, a CPU 1 including a microcomputer is provided to control the essential parts of a sewing machine. A pattern data memory 2 has the stitch data of predetermined zigzag patterns stored therein and is connected to the CPU 1 . An indication data memory 5 has the indication data stored therein as corresponding to the patterns stored in the pattern data memory 2 and is connected to the CPU 1 .
A pattern selecting/combining device 3 is provided so as to be operated by a machine user to select one or a plurality of patterns in combination from the patterns stored in the pattern data memory 2 . A pattern modifying device 4 is provided so as to be operated by a machine user to modify, for example, to reduce, enlarge or reverse the selected pattern or patterns.
A pattern indicating device 8 is provided to indicate thereat the pattern or patterns selected by the pattern selecting/combining device 3 so that the indicated pattern or patterns may be confirmed by the machine user.
An indication data combining device 6 is provided to form up a list therein of the patterns which are selected in combination. An image treating device 7 is provided to treat the image of combined patterns in accordance with the pattern list so that the treated image of patterns may be indicated at the pattern indicating device 8 .
In case the selected pattern or patterns are to be modified, a pattern modifying signal is transmitted to the image treating device 7 so that the modified image of a pattern or patterns in combination may be indicated at the pattern indicating device 8 .
A cursor device 9 is provided which is operated with operation of a button or the like by the machine user to indicate a cursor at the indicating device 8 so that the cursor may be used to point to an optional one of the patterns indicated at the pattern indicating device 8 . The cursor may be pointed to a pattern which is to be indicated at an initial position or which is to be modified.
The pattern data selected, combined and modified by the pattern selecting/combining device 3 is recorded in a pattern data recording memory 50 . A stitching mechanism 51 is operated to perform a stitching operation in accordance with the pattern data recorded in the pattern data recording memory 50 .
As is described hereinbefore, the indication data combining device 6 will operate to form up a list of indication data in reference to the indication data stored in the indication data memory 5 in accordance with the patterns combined by the pattern selecting/combining device 3 , and the image treating device 7 will produce the indication data on the basis of the indication data list so that the indication data corresponding to the combined patterns to be stitched may be indicated at the indicating device
Further, in response to a pattern modifying signal, the image treating device 7 will produce new indication data on the basis of the indication data stored in the indication data memory 5 so that a modified pattern may be indicated at the indicating device 8 .
According to the embodiment, the combined patterns are indicated as arranged linearly from left to right as shown in FIGS. 2 through 4. The image treating device 7 will treat the image of patterns so as to be continuous to one another in case the patterns are of an identical type.
FIG. 2 shows that a pattern 60 and a pattern 61 are in a combined state. In this case, the stitch end point E 0 of the pattern 60 may be indicated as the stitch start point S 1 of the pattern 61 .
However as shown in FIG. 3, in case a pattern 62 is repeatedly stitched in series wherein the stitch end point E 2 is not at the end of the pattern and terminates at a stitch start point S 2 , it becomes necessary to make a special treatment of pattern image. More precisely, as shown in FIG. 4, in case the second pattern 63 of the same pattern is indicated in the first position at the pattern indicating device 8 , it becomes necessary to indicate a portion D of the pattern 62 which overlaps the stitch start point S 3 of the pattern 63 .
The indication may be realized by a special treatment of pattern image as follows:
In FIG. 5, when the first pattern is selected, the initial data is decided from the position data of a cursor so that a cursor 90 may come to an optional position in the indicating device 8 while the currently indicated data is disappeared, and then the pattern image position is initialized (Steps S 1 , S 2 , S 3 ). Subsequently the indication data for the initial pattern is read out (step S 4 ). Subsequently it is determined whether or not the read out indication data is identical with the preceding indication data (step S 5 ). In case the read out indication data is identical with the preceding indication data, the image treatment jumps to the subroutine (FIG. 6) (step S 6 ). In case the read out indication data is not identical with the preceding indication data, the pattern which is at the cursor position is turned to blue and a cursor line is drawn (steps S 7 , S 8 , S 9 ) while the other patterns are treated to turn to red (step S 10 ), and then the indication of pattern is started from the pattern image start position (step S 11 ). Subsequently, the width between the pattern indication start point and the pattern indication end point of the pattern indication start data is needed to the pattern image position to make the next indication start point (step S 12 ). Subsequently it is checked whether or not the next data exists in the list (step S 12 ). In case the next data exists, the indication of the next indication data is carried out (step S 14 ). In this case, it is checked whether or not the indicating area of the pattern indicating device 8 remains to be further available (step S 15 ). In case there is no indicating area remaining available, the image treatment is finished. In case the indicating area remains, the image treatment returns to step S 7 and the same operation is repeated.
The pattern image treatment at the step S 6 will be described in reference to FIGS. 4 and 6.
The indication data for the initial pattern 63 is read out (step S 20 ) and the pattern image start position is initialized (step S 21 ). Then as shown in FIG. 4, it is discriminated whether or not there is the portion D overlapping the preceding pattern (steps S 22 , S 23 ). In case there is no overlapping portion, the image treatment comes to end. In case there is an overlapping portion, it is discriminated whether or not the preceding pattern 62 is identical with the currently indicated pattern 63 (step S 24 ). In case the preceding pattern is not identical with the currently indicated pattern, the image treatment comes to end. In case the preceding pattern is identical with the currently indicated pattern, the indication data for the preceding pattern 62 is set as a pattern image start data (step S 25 ) and the pattern image start position is displaced to the pattern image start point S 2 of the preceding pattern 62 by the data width (step S 26 ). In case the pattern image start data is the initial data of the pattern list, the image treatment comes to end (step S 27 ). In case the width of the pattern image start position fails to exceed the overlap width D, it becomes necessary to further displace the pattern image start position. In this case, the image treatment is returned to the step start point S 24 (step S 28 ).
As is described above, provided that at the step S 26 , image treatment is started from the pattern 62 while the pattern 63 is indicated as the initial pattern at the pattern indicating device 8 , the overlap portion D at the end part of the preceding pattern 62 may be properly indicated at the pattern indicating device 8 as shown in FIG. 4 .
In case a plurality of optionally selected patterns are stitched in combination, the indication data for the patterns may be indicated at the indicating device and may be changed in accordance with the change of the selected patterns. Thus the machine user may confirm the patterns to be stitched before starting the stitching operation of the patterns.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications are intended to be included within the scope of the following claims.
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Disclosed is a sewing machine having an indicating device for indicating selected patterns in a manner that the same may be substantially the same with the actually stitched result of the selected patterns, wherein the patterns selected by a user by operation of a pattern selecting/combining device 3 are indicated at an indicating device 8 and wherein in response to an optional combination or modification of the selected patterns, an image treating device 7 accordingly treats the image of the indicated patterns to indicate the same at the indicating device 8 . The pattern data are stored in a pattern data memory 50 and a stitching mechanism 51 is operated in accordance with the pattern data stored in the pattern data memory 50 , thereby to form the patterns of stitches.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 07/392,669, filed Aug. 11, 1989 now abandoned, which in turn is a continuation of application Ser. No. 208,834 filed Jun. 16, 1988, now U.S. Pat. No. 4,903,472 granted Feb. 27, 1990, which in turn is a continuation of application Ser. No. 940,508 filed Dec. 11, 1986, now abandoned, which in turn is a continuation-in-part of application Ser. No. 904,768 filed Sep. 5, 1986, now abandoned, which in turn is a continuation of application Ser. No. 600,363 filed Apr. 13, 1984, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a process and apparatus for the spinning of fiber yarns, possibly comprising at least one core.
The production of the threads can be effected on numerous spinning systems. Ring-traveler systems, self-twisting systems, free-end systems, braiding systems, etc. are known.
One special type of thread consists of the core threads in which a core thread is wrapped with a sheathing of staple fibers. Methods of producing core threads are described, in particular, in U.S. Pat. Nos. 1,373,880, 2,024,156, 2,210,884, 2,313,058, 2,504,523, 2,526,523, 3,017,740 and 3,038,295.
The production of core threads can be effected on numerous systems of spinning commonly employed for the manufacture of threads from staple fibers. However, particularly in the case of the ring-traveler system, spun core threads generally have the drawback of being limited in speed of production to the speed of the machines used and therefore to the system of twisting employed.
Self-twisted core threads are known from U.S. Pat. No. 4,033,102. An original manner of producing self-twisted core threads is described in French Patents 7,918,173 and 7,913,995. The advantage of this process is that it requires only unidirectional movements of constant speed. On the other hand, its great drawback is that it imposes sudden, extensive variations in twist, and therefore in tension on the thread, which limit the effectiveness thereof with respect to the speed of production and increase the danger of the sliding of the cover fibers with respect to the core.
French Patent 8,111,642 avoids these drawbacks and permits a high speed of production without sliding of the cover fibers with respect to the core and produces, after doubling, a unidirectional torsion of the twist. Its great drawback is that it requires the use of one or more continuous filaments serving as vector for the cover fibers, which may be a drawback in the final product.
The present invention makes it possible to obtain fiber yarns with or without cores with an extremely high speed of production, obtained by the consolidating of the strength of the fiber yarn, preferably at the time when it must withstand stresses.
Conventional spinning processes, such as described in U.S. Pat. Nos. 4,414,800 and 4,484,436, include the following steps:
(a) drafting at least two rovings of fibers to intermediate yarns;
(b) false twisting the intermediate yarns;
(c) assembling the intermediate yarns; and
(d) twisting the assembled intermediate yarns to a twisted yarn.
The twisting of the assembled intermediate yarns may be accomplished by winding the assembled intermediate yarns by means of a two-for-one twister to a twisted yarn.
Such conventional processes produce a fiber yarn which primarily has two twisted and assembled intermediate yarns without a core. However, it is also possible that a core may be present.
SUMMARY OF THE INVENTION
The present invention relates to the problem of breaking of the yarn during the spinning process. Breaking occurs particularly in two circumstances:
(1) at the start of the spinning (or the piecing) of the yarn; and
(2) during twisting of the assembled intermediate yarns to a twisted yarn.
The present invention is directed to improvements to conventional spinning processes which serve to overcome the problem of breaking.
It is therefore an object of this invention to provide a process for spinning a yarn of fibers by drafting at least two rovings of fibers to intermediate yarns, false twisting the intermediate yarns, assembling the intermediate yarns and twisting the assembled intermediate yarns to a twisted yarn, which process operates in an efficient manner and can be advantageously operated efficiently at high speeds.
Another object of this invention is to provide a spinning process in which breakage of the yarn is decreased.
A further object of this invention is to provide a process for spinning a yarn which produces a yarn of increased strength.
The foregoing and other objects are attained in accordance with the present invention.
In one embodiment, a process is provided for start spinning or piecing at least two yarns of fibers, which process includes forming strands for start-spinning or piecing by introducing a continuous filament into each roving, false twisting the strands, assembling the strands at a given point of convergence, cutting each filament upstream of its introducing point, removing the filament from the strands and twisting the strands without the filament to a twisted yarn.
The present invention provides a valuable advance over the state of the art. When starting a spinning process, such as after a break in the yarn, the strength of the intermediate yarn drafted from the rovings of fibers is not sufficient to allow the process to work correctly. To obviate this problem, applicant has discovered that by adding continuous filament to each roving of fibers upstream of the drawing rolls, the strands of drafted rovings and continuous filaments advantageously run through the drawing rolls and the twister.
The present invention provides a process which can produce a fiber yarn without a core. Therefore, the continuous filament is needed only temporarily and means are provided for its removal. Thus, continuous filament is advantageously cut upstream of its introducing point, that is, upstream or before the drawing rolls. Further, the cut filament can be separated from the yarn by a removing device, such as a suction device, preferably located upstream of the winding roll and final twisting means.
The continuous filament is "continuous" only in the sense that it runs continuously when necessary. Clearly, the continuous filaments are not introduced into the rovings when not necessary and, in any case, are removed before final twisting. Preferably, the final strands which are twisted do not contain the continuous filaments.
A further embodiment of the present invention concerns the problem of breaking while twisting the assembled intermediate yarns to a twisted yarn. By the present invention, this problem of breaking is advantageously avoided by introducing a false twisting of the assembled intermediate yarns, supplementary to the false twisting of the intermediate yarns, before the last twisting.
These advantages are achieved by a process for the spinning of fiber yarns in which at least one roving of fibers is drawn between feed points of said roving and pairs of drawing rolls, upstream of which a continuous filament is introduced and, in accordance with the invention, the strands formed by each roving of fibers and each continuous filament are twisted by a twisting member, preferably a friction-twisting member, by causing them to converge at one and the same point located upstream or downstream of the twisting member. The thread thus formed is passed through a pair of delivery rolls located behind the twisting member, the thread is wound onto a suitable support and the thread thus formed by the strands is possibly doubled on a doubling frame.
This process is such that at a given precise point the thread is imparted sufficient coherence to permit the doubling. Thus the fiber yarn is not broken. The coherence is preferably imparted to the thread between the point of the taking on of twist and the point of the winding of the thread.
The thread which is thus formed in accordance with the invention is doubled on a conventional doubling frame, for instance of ring-traveler, double-twist or double-stage type in order to impart the final twist.
In accordance with another embodiment, the coherence is imparted to the thread by sizing the fibers, namely by the addition of a cohesive product to the fibers, for instance, before fiber rovings are drawn, in particular at the time of the preparation of the rovings or, more preferably, after the twisting of the strands and before the winding up thereof.
In accordance with the invention, the thread which is wound up is such that there is no assembling twist, which is avoided by adjustment of the tension. In the event that such assembling twist should exist due to the irregularities in operation of the twisting member related to the irregularities in mass of the thread, it is a non-uniform random twist or alternate twist or self-twist. It is therefore not uniform either in pitch or in intensity. The invention makes it possible to avoid such an undesired assembling twist of the wound-up thread.
In order to produce a core-less thread, the continuous filament or filaments are cut before the winding is effected. The continuous filament or filaments are preferably cut upstream of the drawing rolls. This constitutes a method of starting manufacture which is in no way limitative and other manners of procedure can be contemplated.
In accordance with one particular embodiment of the invention, at least two rovings of fibers are drawn separately between feed points and pairs of drawing rolls; the continuous threads are fed; they are introduced into said rovings upstream of the different drawing rolls; and the strands formed are caused to converge at a given point of a twisting member. The strands formed are passed through a pair of delivery rolls and the continuous filaments cut, upstream of the drawing rolls, before the winding up of the remaining assembly. The assembly formed by the fibers is then placed on a doubling frame where strength of the thread is assured between the point of winding of the thread on the bobbin and the point of the taking on of twist.
This purpose is also achieved by a device for the spinning of fiber yarns comprising possibly at least one continuous filament and having:
means for producing at least two strands of fibers,
means for feeding at least one continuous filament into each strand,
means for the false twisting of the strands, preferably by friction,
means for regulating the tension of the strands, preferably located downstream of the twisting means, and possibly means for eliminating the continuous filament,
winding means,
means for twisting the yarn,
means imparting sufficient coherence to permit doubling.
Preferably, the coherence means are located between the point of winding of the thread on the bobbin and the point of the assumption of torsion upon doubling.
In accordance with the invention, the thread which is wound has a very special structure. In fact, it is formed of at least two strands placed side by side and having a small residual twist, possibly alternate and very slight, sufficient to assure coherence of the cover fibers on the filament and insufficient to cause the assembling of the two strands by self-twisting in uniform and constant manner.
Finally, the thread after doubling is such that the fibers are all substantially parallel to each other in the axis of each strand with a variation equal to the very slight residual twist present in the thread before doubling, but such that one can dissociate the two strands by untwisting.
There is actually concerned a two-strand thread.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention and the advantages which it provides will, however, be better understood from the embodiments of its reduction to practice which are given below by way of illustration but not of limitation and which are shown in the accompanying drawing, in which:
FIG. 1 is a diagrammatic view, in perspective, of a spinning apparatus before the stopping of the continuous filament in the event that the point of convergence is upstream of the twister;
FIG. 2 is a diagrammatic view, in perspective, of an apparatus for the obtaining of a double thread before the placing in torsion and after the cutting of the filament, in the event that the point of convergence is downstream of the twister;
FIG. 3 is a perspective view of a device which makes it possible to obtain strength of the yarn between the point of winding of the yarn on the bobbin and the point of assumption of torsion of a doubling frame;
FIG. 4 is a sectional view through the device of FIG. 3, mounted on the winding reel of a double-twist doubler;
FIG. 5 is a perspective view of a variant of the device of FIG. 3;
FIG. 6 is a perspective view of another variant of the device of FIG. 3;
FIG. 7 is a diagrammatic view of the device of FIG. 5, mounted on a ring-traveler doubling frame;
FIG. 8A is a view of the thread after doubling in accordance with the invention;
FIG. 8B is a view of a thread of the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the invention, a spinning process is carried out by drawing a roving of fibers 5a between a feed point 2a and a pair of drawing rolls 4a. The drawing system comprises furthermore a pair of drawing belts 3a. Parallel to this, a roving of fibers 5b is drawn separately by a drawing system comprising a feed point, namely a pair of feed rolls 2b, a pair of drawing belts 3b and a pair of drawing rolls 4b.
Upstream of the drawing rolls (4a, 4b) a continuous filament (6a, 6b) is introduced. There are thus formed two strands, each consisting of a roving of fibers and a filament. The strands thus formed are twisted together by a twister 7 and are guided by two guides 8 and 9. The two strands then pass through a pair of rolls 10 before being drawn in by a suction device 13 before eliminating the continuous filaments for instance by cutting, by means of a pair of manual shears, upstream of the drawing rolls.
The continuous filaments which have thus been cut are therefore led away to waste by the suction device 13.
FIG. 2 shows the spinning device after the cutting of the filaments, when the yarn of fibers is wound on a roll 11.
It is important to have a number of fibers in sufficient cross section relative to the coherence of the fibers, the cleanness of the roving and the tension between the drawing rolls 4 and the delivery rolls 10. With respect to the coherence between the fibers, it may be of interest to add to th fibers, at the time of the preparation of the rovings, a size which increase this coherence between the fibers, for instance, a paraffin size or a size containing colloidal silica. This also has the effect of facilitating the doubling.
In the event that the point of covergence is upstream of the twisting member, it is also important to regulate the tension between the drawing rolls and the delivery rolls 10 in such a manner as to have a suitable distance h between the drawing rolls 4 and the point of coinvergence 12 of the threads, relative to the twist imparted and the speed of travel. In fact, a twist is present in each of the individual strands between the point of convergence 12 of the strands and the point where the strand is grasped last by the drawings rolls 4, but this twist is not incorporated in the resultant thread. This twist is present in the strands prior to the convergence in an equilibrium amount which depends on the geometry of the system and the spinning parameters. This state of affairs described above may, in practice, be modified. In fact, irregularities being present at random in the strands, a part of the twist is incorporated in strands in a randomly varying manner. Such a twist is, however, of slight intensity.
If the tension is too little, then tool little torsion is present in the strand between the drawing rolls 4 and the point of convergence 12, which results in losses of fibers at the outlet of the drawing rolls 4, as a result of poor interlocking of the fibers. For example, excellent results have been obtained with a speed of 215 meters per minute with a draw, between the drawing rolls 4 and the delivery rolls 10, of 1.53% and a thread of 2×25 tex composed of 45% wool of 27 microns and 55% polyester of 3 denier. Thus, the difference in speed between the drawing rolls 4 and the delivery rolls 10 is adjusted as a function of the spinning parameters and the speed of travel. If the tension, on the other hand, is too great, the thread is excessively tensioned, resulting in the risk of breakage.
In the event that friction-twisting members are employed which assure both a component of twist and a component of advance of the thread, it may be of interest to adjust the tension of the thread by varying this component of advance, independently of the adjustment of the tension between the delivery and drawing rolls. For example, when two endless crossed belts are used, this adjustment is effected by variation of the angle of the two belts.
By the present invention, the problem of breaking while twisting the assembled intermediate yarns to a twisted yarn is advantageously avoided. When the yarn of fibers is at the stage of the doubling, its strength is, in general, too slight to permit operation without problems and the thread frequently breaks between the point of winding of the thread on the bobbin and the point of the assumption of twist.
Now it has been found that a very slight additional coherence was sufficient to assure the winding of the thread. As a function of the initial coherence of the fibers, a simple cohesive sizing may be sufficient. This cohesive product may be added to the fibers either at the time of the preparation of the rovings or at the location of the spinning machine, between the strand twisting member and the winding member.
In cases in which this is not sufficient or in cases in which sizing is not to be effected, it has been found that the addition of a few turns of twist, by means of a false twisting device, made before the final twisting was sufficient to assure a good winding.
False twisting devices are known. They may be rotary or operate by friction. They may be static and a single winding on a rod may assure a twisting by rolling upstream of the rod when pulling on the thread, provided that the angle of the thread with respect to the rod, the diameter of the rod as a function of the diameter of the thread, as well as the pitch of the thread on the rod and the coefficient of friction of the material of the rod are properly selected.
The example of FIG. 3 is a device which satisfies these requirements. In consists of a body 14 of light material which supports a rod 15 having the form of a semicircle arranged on the upper part of the body 14.
The use of the device of FIG. 3 will, however, be better understood from FIG. 4 which show a cross section through a double-twist boubling spindle in which the bobbin of threadd 16 is placed on the pot 17 where it is centered by the centerer 18. The unwinding thread 19 upon leaving the bobbin passes through the eye 20 of the winding reel 21. The thread is then wound on the rod 15 which is supported by the body 14, itself fastened by any means (not shown) on the reel 21. After having effected a certain number of turns, the thread returns into the body of the extender 22 where it will receive the first turn of twist imparted by the torsion disk (not shown) in order then to pass between the pot 17 and the anti-balloon wire 23 where it receives the second turn of twist before being wound on a bobbin (not shown).
In general, in a double-twist doubling machine, the tension of the thread and therefore the number of winding turns on the torsion disk is adjusted by a spring piston, a torsion blocker, not shown, which is located in the extender 22.
In the case of the user of the device according to the invention it is necessary either to remove this pistion and thus the twist moves back to the rod 15, or to have a distance between this piston and the rod 15 which is less than the length of the fibers.
When using the device, the tension of the thread is adjusted by varying the following parameters:
number of turns of winding of the thread 19 on the rod 15;
diameter of the rod 15;
coefficient of friction of the material of the rod 15;
angle alpha formed by the thread 19 and the rod 15 at the time when the thread arrives on the rod.
One can vary the rotation of the reel 21 by conventional means, for instance its weight, its coefficient of fricition, etc. One can, as in the case of a conventional double-twist doubling machine, vary the force of the spring of the torsion blocker, in the event that one is used.
For example, good results have been obtained with the thread of 2×25 tex described previously on a double-twist doublign frame with a spindle speed of 11,000 rpm and a twist of 371 turns per meter, namely a developed length of 59.2 meters per minute, using the device described in FIG. 4 in which the thread made one turn on a spring steel rod of 0.5 mm diameter, without using a twist blocker.
Good results were obtained with a thread of 22×33 tex one of the strands of which is formed of a filament of 300 denier of bright triacetate, without fiber coverage and the other strand is formed of 100% acrylic fibers dull, 3 denier, without filament. The assembly being twisted to 260 turns of spindles at a double-twist spindle speed of 10,000 rpm using the device described in FIG. 4 in which the thread 19 made two winding turns on the rod 15 which had a diameter of 0.25 mm, and without using torsion blocker.
A variant of the device is shown in FIG. 5, in which the thread is wound on a straight rod.
As a function of the threads to be doubled, one can have different angles between the rod and the vertical so as to change the angle of the thread with respect to the rod in order to vary the intensity of false twist.
The examples of forms of the device described are given by way of illustration and not of limitation. The only requirement is that there is a winding of the thread on the rod with a suitable angle of the thread with respect to the rod. More generally, one uses any device which permits false twisting between the winding-on and the assumption of twist, which permits the winding of the thread upon the twisting without it breaking due to its small strength.
Another variant of the device is shown in FIG. 6 where the rod is spiraled in the shape of a cone.
In the event that doubling is effected by a different doubling technique, for instance with a ring doubling frame as shown in FIG. 7, it will be sufficient to place a rod 24 between the bobbin 25 and the delivery rolls 26 in order to have a certain angle of the thread with respect to the rod so as to impart sufficient false twist for the winding, in order to obtain a distance between the rod and the delivery rolls less than the length of the fibers. In this case the tension is determined by the weight of the traveler 27.
In the event that doubling is effected by the double-step doubling technique, it will be sufficient to adapt the device of FIG. 7 to the first doubling assembling step.
Thus, in accordance with the invention one obtains a yarns of fibers comprising at least two strands which does not have any discontinuity such as knots, splices or stoppage points and which permits the production of bobbins of thread of large weight, for instance of a weight of at least 1 kg in the case of fine threads, for instance of about 10 tex, and bobbins of thread of at least 10 kg in the case of thick threads, for instance threads of about 1000 tex.
One such thread is shown in FIG. 8A. As can be seen, the fibers 28 are substantially much more parallel to each other than the fibers 29 of a thread of the prior art, all other things being equal.
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The present invention relates to a process for start spinning or piercing at least two yarns of fibers, which process includes forming strands for start-spinning or piecing by introducing a continuous filament into each roving, false twisting the strands, assembling the strands at a given point of convergence, cutting each filament upstream of its introducing point, removing the filament from the strands and twisting the strands without the filament to a twisted yarn. This process serves to overcome the problem of breaking at the start of the spinning. Also by the present invention, the problem of breaking while twisting the assembled intermediate yarns to a twisted yarn is avoided by introducing a false twisting of the assembled intermediate yarns, supplementary to the false twisting of the intermediate yarns, before the last twisting.
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CONTRACTUAL ORIGIN OF THE INVENTION
The United States Government has rights in this invention pursuant to Contract No. DE-AC07-76ID01570 between the United States Department of Energy and EG&G Idaho, Inc.
This is a continuation of application ser. No. 08/010,089, filed Jan. 27, 1993.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to means and method for spray-forming a metal, polymer, or metal/polymer matrix deposit on a substrate and, in particular, to means and method for pressurized injection liquid-feed spraying.
2. Discussion of the Prior Art
This invention relates to a method and apparatus for producing a spray of finely atomized liquid droplets of controlled size distribution, velocity, heat content, flux, and flow pattern. The primary function of the device is to spray form near-net-shape solids and coatings of metals, polymers, and composite materials by directing a spray of atomized droplets onto a suitably shaped substrate or mold. Powders of these materials are produced by allowing the droplets to solidify in-flight.
Tremendous growth in the science and technology of atomization has occurred in the past decade. The discipline is now recognized as a major international field of research. Atomization of liquids involves the disintegration of a bulk liquid into fine droplets, and devices used to generate atomized sprays are designated as atomizers or nozzles. Methodologies for generating sprays include discharging a liquid at high velocity into a relatively slow-moving stream of air or other gas, the ejection of a liquid from the periphery of a cup or disk rotating at high velocity, and the exposure of a relatively slow-moving liquid to a high-velocity gas. The latter approach is employed in the present invention.
Atomized sprays find use in a wide range of applications including spray-drying, cooling, combustion, painting, and powdered metal production. Spray-forming is another application of atomized sprays but differs in that atomized droplets of engineered alloys, plastics, and composite materials are spray-deposited onto a suitably shaped substrate or pattern to produce a free-standing, near-net-shape, or net-shape solid. The properties of the spray-formed product reflect the interplay of the characteristics of the spray plume and substrate onto which the spray is deposited. Spray-forming can offer unique opportunities for simplifying materials processing without sacrificing and, oftentimes substantially improving, product quality. In addition to near-net-shape fabrication capabilities, spray-forming is applicable to a wide range of metals and nonmetals and offers property improvements through rapid solidification (e.g., in the case of metals, refined microstructures, extended solid solubilities, and reduced segregation). Economic benefits result from process simplification and the elimination of unit operations. In addition to general spray-forming applications, the present invention has also been used to form coatings and powders of metals, polymers, and composite materials.
This instant invention is an improvement to the spray-forming process which has been developed at the Idaho National Engineering Laboratory (INEL), which is currently referred to as the Controlled Aspiration Process (CAP). The CAP process is set forth in detail in U.S. Pat. No. 4,919,853 issued to Alvarez and Watson on Apr. 24, 1990, and entitled "Apparatus And Method For Spraying Liquid Materials", the disclosure of which is herein incorporated by reference. The CAP process of spray-forming metals aspirates a molten metal into the throat of a converging/diverging gas nozzle, where the liquid is atomized into a directed spray of rapidly cooling droplets. The gas flowing in the nozzle may be ambient air or an inert gas which then accelerates the aspirated molten metal droplets toward a suitable substrate, against which the droplets impact before completely solidifying. Under ideal operating conditions, the incident metal consolidates into a suitable deposit.
Some problems occur with reproducible ideal operating conditions. In some instances, the molten metal does not atomize into a uniform cross-section spray. Aspiration only works within a narrow range of gas supply pressures. This difficulty is heightened by liquids within certain properties, such as, for example, kinematic high viscosity. Aspiration also limits the location of the liquid feed tube within the throat area of the nozzle. Aspiration limits particle size, particle size distributions, particle velocities, particle cooling rates, nozzle geometry, etc. Accordingly, it would be desirable to have an alternative means and method for atomizing the molten metal within a spray nozzle, as to provide for greater flexibility for controlling the properties of the spray which in turn dictate the properties of the spray-formed deposit.
SUMMARY OF THE INVENTION
This invention provides a method and apparatus for producing a spray of finely atomized liquid droplets of metals, polymers, and composite materials by gas atomization of the bulk liquid. Independent control of the atomizing gas velocity, liquid-feed rate, atomizing gas temperature, and other parameters provides flexibility for controlling the atomization behavior of the liquid, the gas/liquid heat-transfer behavior, and the multiphase flow behavior of the spray.
The primary function of the invention is to spray-form near-net-shape solids and coatings of metals, polymers, and composite materials by directing a spray of atomized droplets onto a suitably shaped substrate or mold. Control of size distribution, velocity, and heat content of the atomized droplets as well as the flux, and flow pattern of the spray are important attributes of the invention since they critically influence the properties of the spray-formed product. Powders of metals, polymers, and composite materials are also produced by allowing the atomized droplets to solidify in-flight.
Atomization of the bulk liquid is accomplished by pressure feeding the liquid through one or more orifice into the flow channel of a nozzle having a converging/diverging or converging geometry that is transporting high-temperature gas at flow velocities ranging from high subsonic through supersonic. The gas disintegrates the liquid and entrains the resultant droplets in a highly directed two-phase (or multiphase) flow. For metals, in-flight convection cooling of the droplets followed by conduction and convection cooling at the substrate results in rapid solidification of the deposit. This restricts grain growth and improves product homogeneity by reducing the segregation of impurities. The shape of the spray-formed object is largely dictated by the geometry of the substrate or pattern onto which the spray is deposited, allowing complex shapes to be readily produced. The device has been used to produce spray-formed products of metals, polymers, and polymer/metal matrix composites having a wide variety of shapes and applications. Multiple nozzles, or multiple liquid feed ports on a single nozzle, are utilized for co-depositing more than one metal, ceramic, or polymer. Aerosols containing solid particles are pressure-fed into the nozzle with a molten metal or polymer when spray-forming particulate reinforced metal and polymer matrix composites.
Briefly, then, the present invention comprises a means and method for pressurized feed injecting of a molten metal, polymer, or metal/polymer matrix composite liquid material into a pressurized gas flow which atomizes and accelerates the molten metal droplets toward a desired substrate. The means and method of injecting the molten metal into the pressurized gas flow provide a more efficient atomization of the liquid metal into suitable droplets as well as a uniform and controllable liquid feed behavior. The molten-metal injection delivery may be timed (pulsed) to provide a repeatable batch delivery of atomized metal droplets to a desired substrate.
The means and methods of controlled molten-metal injection into pressurized gas flow of the invention includes injecting the molten metal to any desired portion of the pressurized gas nozzle, such as, for instance, any predetermined distance from the nozzle discharge or the input gas flow to the nozzle, any predetermined injection area across the radial cross-section of the nozzle, and in any direction relative to the pressurized gas flow. Preferred embodiments of the invention then encompass injecting the pressurized metal into the nozzle, throat, downstream of the throat, or upstream of the throat in the direction of the gas flow, 180° out of phase with the direction of the gas flow, and any angle of incidence with the gas flow therebetween. Preferred embodiments of the invention also include reducing the pressure within the liquid reservoir sufficient to interrupt the flow of liquid and interrupt the injection of liquid into the pressurized gas flow to provide for timed/pulsed batch deposition.
Other objects, advantages, and capabilities of the present invention will become more apparent as the description proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be better understood and further advantages and uses thereof may become more readily apparent when considered in view of the following detailed description of the exemplary embodiments, taken with the accompanied drawings, in which:
FIG. 1 is a front, partial-elevation view of the pressurized injection-feed spray apparatus constructed according to the teachings of the invention;
FIG. 2 is a side section view taken along lines 2--2 of FIG. 1 illustrating a converging/diverging spray nozzle having a liquid inlet in the converging portion of the nozzle ;
FIG. 3 is a side section view taken along lines 2--2 of FIG. 1 illustrating a converging spray nozzle embodiment of the invention;
FIG. 3A is a front elevation taken along lines 3A--3A of FIG. 3
FIG. 4 is a side section view taken along lines 2--2 of FIG. 1 again illustrating a converging/diverging nozzle having a liquid inlet in the diverging portion of the nozzle architecture, and showing liquid contained in the reservoir and the liquid flow through the liquid orifice down to the spray nozzle and the spray pattern resulting therefrom;
FIG. 5 is a graph showing the velocity of gas inside and external to the spray nozzle of the present invention for various nozzle-inlet pressures;
FIG. 6 is a graph showing the velocity of gas at the exit plane of the spray nozzle of the present invention for a particular operating pressure;
FIG. 7 is a plot of static pressure at the liquid inlets measured as a function of nozzle-inlet pressure;
FIG. 8 is a tin powder sample, consisting primarily of spherical particles, formed using the method and apparatus of the present invention;
FIG. 9 is another tin powder sample, consisting of a mixture of spherical and prolate ellipsoidal particles, formed using the method and apparatus of the present invention;
FIG. 10 is still another tin powder sample, consisting of irregular particle shapes, formed using the method and apparatus of the present invention;
FIG. 11 is a histogram plot showing the count-frequency distribution versus powder size of tin sprayed according to the methods and apparatus of the present invention;
FIG. 12 is a histogram plot showing the mass-frequency distribution versus powder size of tin sprayed according to the method and apparatus of the present invention;
FIG. 13 is a plot that gives the calculated velocity of a 20 μm tin droplet as a function of distance from the exit of the spray nozzle of the present invention for various nozzle pressures;
FIG. 14 is a plot that gives the calculated temperature of a 20 μm tin droplet as a function of distance from the exit of the nozzle of the present invention for various liquid-metal temperatures;
FIG. 15 is a photomicrograph of spray-formed tin deposit produced according to the method and apparatus of the present invention;
FIG. 16 is a photomicrograph of conventionally cast tin;
FIG. 17 is a photomicrograph of a spray-formed polymer deposit produced according to the method and apparatus of the present invention;
FIG. 18 is a photomicrograph of a particulate-reinforced metal matrix composite consisting of silicon carbide particulate embedded in an aluminum 6061 alloy matrix produced according to the method and apparatus of the present invention.
FIG. 19 is a side-section view of a multiple liquid metal disposition apparatus; and
FIG. 20 is a side-section view of an aerosol injection apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and to FIGS. 1-4, in particular, there is shown a front partial-elevational view of a pressurized liquid injection-feed spray-forming apparatus and three side section views of converging/diverging (FIG. 2), converging (FIG. 3), converging/diverging but with a different feed location (FIG. 4) spray nozzle embodiments of the invention, taken along the lines 2--2 of FIG. 1, respectively. Pressurized liquid injection-feed spray-forming apparatus 10 includes a pressurizable liquid reservoir 12 and spray nozzle 14. Pressurizable liquid reservoir 12 includes body 16 and lid 18 which has multiple passages 22 fitted with suitable leak-type fittings 24 and couplings 26, so as to allow pressurized conduits, such as, for instance pressuring means 27, inert-gas inlet tube 28 valve 29 (FIGS. 1, 2, and 4), pressure tap 32, thermocouple's 34 instrumentation wires 36, and stopper rod 38. Stopper rod 38 is in mechanical communication with feed-injection valve 42, which fits in interruptible fluid communication with valve seat 44. Spray nozzle 14 includes body 16 having a gas-flow channel 46 passing therethrough. Gas-flow channel 46 has a predetermined architecture which will be described later. Liquid-orifice inlet 48 is in fluid communication with valve seat 44 through conduit 52 such that, when feed-injection valve 42 is opened, reservoir fluid 54 flows into flow channel 46 and is atomized by the gas flow therein producing spray pattern 56. Both liquid reservoir 12 and spray nozzle 14 are circumvented by heaters 58, the operation of which will be described later.
Again, referring to FIGS. 1-4, the main components of the pressurized feed-injectant spray apparatus 10 of the invention, then, are the pressurizable liquid reservoir 12 and the spray nozzle 14. Each is independently heated to the desired temperature by heaters 58 using conventional methods such as resistance heating, induction heating, electron bombardment heating, etc. The nozzle body is heated to prevent the liquid from freezing before entering the gas flow channel where atomization occurs. Conventional heating methods are also used to control the temperature of the atomizing gas over a wide range of temperatures. Depending upon the application, gas temperatures ranging from room temperature to above the melting point of the sprayed liquid have been used.
The liquid reservoir and lid are sealed using a heat-resistant gasket 62 which allows the reservoir to be pressurized or evacuated. The liquid reservoir and nozzle are sealed in a similar way using a heat-resistant gasket 64 that is compatible with the liquid to be sprayed as well as the materials of the nozzle and liquid reservoir at the operating temperature. The reservoir's lid contains fittings used to provide leak-tight couplings for inert-gas inlet tube 28, a pressure tap 32 for measuring the pressure of the gas within the reservoir, a thermocouple 34 for measuring the temperature of the liquid, and a stopper rod 38 for starting/stopping the flow of liquid to the nozzle. The inert-gas inlet 28 is used to generate a positive pressure or vacuum above the liquid as desired. This allows control of the feed rate of liquid into the nozzle and control of the atmosphere that the liquid is exposed to. A positive pressure is used to increase the liquid flow rate into the nozzle, and a partial vacuum is used to reduce or prevent the flow of liquid.
The flow channel 46 of the spray nozzle 14 may have a converging section, a constricted section or "throat" 66, and a diverging exit channel 68 (FIGS. 2 and 4) or a straight-walled exit channel 72 (FIG. 3). The former is referred to as a "converging-diverging" design while the latter is a "converging" design. Converging/diverging nozzles having included converging and diverging angles of up to 40° have been designed, constructed, and tested. Cross-sections of the nozzle along the length of the flow channel may be circular 71 FIG. 3A, i.e., the flow channel of the nozzle may have an axis of symmetry down its center along the length of the flow channel or "rectangular" ("linear") as at 73 (FIG. 1), in which case the flow channel has a vertical plane of symmetry down the center of the nozzle along its length. FIG. 1 illustrate nozzles with "rectangular" cross-sections.
The liquid to be sprayed is fed into the nozzle 14 from the liquid reservoir through a liquid orifice inlet 48 which may be, for example, a single tube, a series of tubes, or a linear single-slit orifice 75 of FIG. 21 with predetermined orientations relative to the gas flow that spans the width of the flow channel 46. The termination point of these tubes (or slits) can be located anywhere along the length of the nozzle 14 or within the flow channel 46, and need not be located near the nozzle's throat or constriction. FIGS. 2 and 4 give two examples. In FIG. 4 the acute angle liquid inlets 48 are located near the nozzle's exit 74 to prevent accumulation of the liquid on the walls of the nozzle which would reduce the atomization efficiency. The liquid inlets are usually located where the gas velocity is high to enhance the atomization efficiency. This is possible with the present invention because the flow rate of liquid into the nozzle can be decoupled from the flow rate of gas (or nozzle pressure) through the nozzle by adjusting the pressure inside the liquid reservoir. In principle, any gas-to-liquid mass ratio (G/L) can be achieved by adjusting the flow rate of atomizing gas (nozzle pressure) and liquid reservoir pressure. Choice of liquid inlet dimensions is dictated by desired spray properties such as liquid throughput and G/L. G/L influences the atomization efficiency, increasing the efficiency as G/L increases. In general, for a given throughput, the use of smaller diameter, liquid-inlet tubes (or slit) increases the atomization efficiency. The liquid inlet tubes (or slit) are subject to clogging when they are located within the flow channel as illustrated in FIGS. 2-4. This is due to heat sinking by the surrounding atomizing gas. This condition is circumvented by heating the atomizing gas near the melting point of the sprayed metal. Alternatively, the liquid-inlet tubes (or slit) can be heated using conventional heating techniques, such as resistance heating, to maintain the liquid in a fluid state. A ceramic filter is also often used at the inlet to the liquid-inlet tubes (slit) to prevent clogging from slag or other impurities which may be present in the liquid metal. The liquid reservoir and nozzle are constructed using materials that are compatible with the liquid to be sprayed. Generally, refractory ceramics, such as boron nitride, alumina, and zirconia, are suitable. Some metals are also suitable construction materials for certain applications. Choice of atomizing gas is guided by its physicochemical properties and cost. Normally, a gas that is compatible with the components of the invention and the sprayed liquid is used. Examples include argon, helium, nitrogen, and air. Under some circumstances, however, a controlled reaction between the liquid and atomizing gas is desirable. An example is the use of nitrogen gas when atomizing low-carbon steel alloyed with aluminum. Improvements in the mechanical properties of the spray-formed product are observed due to the formation of aluminum nitride particles which presumably serve as grain-boundary pinning sites that help refine the steel's microstructures. The atomizing gas may also be seeded with reactive species, such as the halogen gases, to initiate polymerization reactions when spray-forming certain polymers.
Liquid metals including various tin alloys, zinc allows, aluminum alloys, brasses, bronzes, copper alloys, stainless steels, carbon steels, and others have been successfully spray-formed using the method and apparatus of the present invention despite the broad differences in the physical properties of these liquid metals.
Multiple liquid metals or polymers are co-deposited by pressure feeding the metals into a single nozzle using multiple feed ports 80 and 82 and pressurizable liquid reservoirs 84 and 86 (FIG. 19) or by using multiple spray nozzles. Polymeric materials are spray-formed using several approaches. Polymers dissolved in an appropriate solvent can be readily sprayed. Control of gas temperature provides a convenient method for varying the evaporation rate of the solvent. Another approach is to melt and pressure feed the polymer into the spray nozzle. A third approach involves in-flight melting (via heated gas) of powdered polymers fed into the nozzle in aerosol form. Metal-matrix and polymer-matrix composites are spray formed by co-depositing the ceramic phase with a metal or polymer, respectively. The ceramic phase is introduced into the nozzle as an aerosol. Typically, this phase is introduced upstream of the entrance location of the metal or polymer. The atomizing gas is used to heat the ceramic phase to the desired temperature. Independent control of both the atomizing gas and liquid metal (or polymer) temperatures allows control of the extent of ceramic matrix interfacial reactions, surface wetting, and bonding.
During a typical spray-forming trial with a molten metal, metal is added to the reservoir and heated above its melting point to the desired temperature while maintaining a purged inert gas atmosphere within the reservoir. Simultaneously, the spray nozzle is heated to near the melting point of the metal to prevent solidification of the melt, and the atomizing gas is heated to the desired temperature. After the nozzle and liquid reservoir pressures are set for the desired spray conditions, the stopper rod is lifted. Liquid metal flows through the liquid orifice(s), which are shown in FIG. 2, by way of example, as a series of tubes protruding midway into the gas stream at a location upstream of the nozzle's throat. Upon contacting the high-velocity gas stream, the metal is sheared and atomized into fine droplets that are entrained in the two-phase flow and transported to a substrate or mold where they rapidly solidify to form a metal deposit. The following experimental conditions are chosen depending upon the physicochemical properties of the liquid to be sprayed, desired spray properties (droplet size, temperature, velocity, flow pattern), desired liquid throughput, desired spray formed product shape, and other considerations: nozzle geometry, liquid orifice size, shape, orientation, and location, substrate material, substrate temperature, substrate or nozzle speed, substrate shape, atomizing gas, liquid temperature, reservoir pressure, nozzle temperature, atomizing gas temperature, static gas pressure at the nozzle inlet, gas flow rate, ambient entrained gas and its temperature, and others.
SPRAY CHARACTERIZATION AND NOZZLE PERFORMANCE RESULTS
Single-Phase Flow Characterization
An understanding of the atomization behavior and characteristics of the flow field are important because the properties of the spray-formed product reflect the interplay of the characteristics of the spray plume (droplet size distribution, velocity, heat content, flux, and flow pattern) and substrate (material properties, surface finish, and temperature). Gas-flow field characterization studies of INEL pressurized feed-injection spray-forming nozzles have been conducted. Their single- and multiphase flow behaviors have also been extensively modelled. Flow-field diagnostics were performed using stagnation and static pressure probes constructed from small-diameter hypodermic tubing. The flow field along the centerline of the nozzle was mapped by traversing the probes from the center of the throat, through the diverging section, and into the free jet region. Gas velocities were calculated from static and stagnation pressure measurements using compressible flow theory at twelve nozzle inlet pressures. FIG. 5 summarizes results for the nozzle design shown in FIGS. 2 and 4--a converging/diverging nozzle with included inlet and outlet angles of 6°. Room temperature argon and a back pressure of about 86 kPa (12.5 psia) were used. Supersonic flows were observed downstream of the throat for nozzle-inlet pressures exceeding about 120 kPa (17.5 psia). The supersonic flow region extended about 10 mm before it began to shock down through what is believed to be a series of weak oblique shocks. The flow was driven to supersonic velocity outside the nozzle with nozzle inlet pressures in excess of about 223 kpa (32 psia).
The flow field was also mapped at the nozzle's exit plane. Results for the velocity profile are given in FIG. 6. The profile is symmetric with no indication of flow separation. Flow separation has been observed and has been computationally verified in nozzles with excessively large divergence angles. This undesirable condition is avoided as much as possible, since it can result in poor atomization performance in terms of large, average, droplet size and a broad distribution of droplet sizes.
The magnitude and uniformity of suction, i.e., the difference between atmospheric pressure and local static pressure at the liquid orifices, were evaluated for a nozzle having inlet and exit angles (included angles) of 6° using static pressure probes placed perpendicular to the flow direction. Results using room temperature argon and a back pressure (i.e., "back pressure" is the ambient pressure at the discharge of the nozzle) of 86 kPa (12.5 psia) are given in FIG. 7. The local static pressure measured at each of six liquid orifices is plotted against the nozzle inlet pressure, giving rise to the envelope of curves. The curve profiles are parabolic-like: the pressure at the liquid orifices decreased with increasing nozzle inlet pressure from atmospheric pressure to a minimum and then increased again. The well depth, which corresponds to the magnitude of the suction, is approximately 42 kPa (6 psia). Above an inlet pressure of approximately 200 kPa (29 psia) the pressure at the liquid orifices rises above atmospheric pressure.
The suction uniformity is best at lower nozzle pressures. At high flows, the individual curves diverge with a larger reduction in suction at liquid orifices nearest the side walls (L.O. #1 and L.O. #6 in FIG. 7) due to drag effects.
As the nozzle wall and atomizing gas temperatures were increased, the depth of the well in FIG. 7 decreased, the well broadened, and the minimum was shifted slightly to lower nozzle inlet pressures. A given nozzle typically exhibited a logarithmic-like dependence of suction with temperature, with a decrease in suction of about 25% as the operating temperature was increased from 300 to 1875K. This was largely due to the increase in gas viscosity.
Operation of the nozzle in the aspiration mode (this is how U.S. Pat. No. 4,919,853' nozzle is operated) is limited to the region within the parabolic-like well in FIG. 7. This limited range of operating pressures is undesirable because it defines a limited range of gas velocities. Atomization of a liquid depends on the square of the velocity difference (V 2 ) between the atomizing gas and the liquid. Furthermore, for a given liquid orifice dimension, the flow rate of liquid into the flow channel depends on the nozzle pressure, and the flow is cut off if the pressure is too high. Atomization efficiency is influenced by the dimensions of the liquid stream entering the nozzle. In order to obtain a large liquid flow rate into an aspirating nozzle, larger liquid orifices are required or a nozzle pressure nearer the minimum in FIG. 7 is required. Both of these will result in a low gas-to-metal mass ratio and poorer atomization efficiency.
Atomization Behavior
During gas atomization, a liquid is disintegrated into relatively fine droplets by the action of aerodynamic forces that overcome surface tension forces which consolidate the liquid. The liquid's viscosity and density also influence atomization behavior but, typically, play a more secondary role. Viscosity affects both the degree of atomization and the spray pattern by influencing the amount of interfacial contact area between the liquid and gas. Viscous liquids oppose change in geometry more efficiently than low viscosity liquids, making the generation of a uniform spray jet more difficult for a given set of flow conditions. Density influences how the liquid responds to momentum transfer from the gas. Light liquids accelerate more rapidly in the gas jet. Disintegration efficiency is reduced because atomization takes place at lower relative velocities.
Liquid metals are characterized by moderately high viscosity, high density, and very high surface tension compared to common liquids such as methanol, water, and acetone. These properties, and the intrinsic high temperature requirements, make the atomization of liquid metals more difficult than with most liquids. As a result, liquid-metal spray-forming nozzles need to be designed to provide good gas/metal coupling with efficient kinetic energy transfer from the gas. With the spray-forming nozzles of the present invention, the liquid metal enters the flow channel with a low axial velocity (for the case of normal injection). There it contacts a high-velocity high-temperature inert gas. High-temperature gas is used to help maintain the liquid metal in a fluid state throughout breakup and to prevent the metal from freezing as it enters the nozzle. Relatively large droplets or sheets form initially which then undergo secondary atomization by various mechanisms depending upon local flow patterns, flow velocity, mass loading, and the physical properties of the gas and liquid metal.
The dynamics of droplet breakup in high-velocity flows are quite complicated. Historically, the Weber number, We, has been a useful predictor of breakup tendency. We represents the ratio of inertial forces to surface tension forces: ##EQU1## where ρ is the density of the gas, V is the relative velocity between the flow field (gas) and the drop, D is the diameter of the drop, and σ is the surface tension of the drop. Breakup of liquid drops will not occur unless the Weber number exceeds a critical value, We crit . The critical Weber number associated with the atomization of liquid tin using the nozzles shown in FIGS. 2 and 4 is estimated to be close to 1 for a nozzle operating at an inlet pressure of 207 kPa (30 psia) absolute, with argon gas heated to 300° C. We crit was calculated for a 14 μm droplet using the surface tension of the bulk liquid at its melting point, and the measured gas and droplet flow velocities. The density of the gas was calculated using compressible flow theory. In contrast, the Weber number associated with breakup of a 3 mm tin droplet at the liquid's injection point is estimated to be about 280 under the same nozzle conditions.
Atomization usually proceeds through stages, producing a range of droplet sizes. High-speed video techniques have been applied to examine metal breakup in spray-forming nozzles of the present design, and at least two breakup mechanisms have been observed depending upon the flow conditions and mass loading. One of these, termed "bag breakup", was observed at low-nozzle inlet pressures. "Bag breakup" has been observed in a number of studies on a variety of liquids in both steady and transient flow fields. This type of breakup, and the related "bag and stamen breakup", has been correlated with initial Weber numbers 12<We<100. In "bag breakup", the center portion of a drop's front surface first becomes concave and then is blown out downstream to form a hollow bag attached to a more massive torroidal rim. The bag bursts, producing a shower of relatively fine droplets and filaments. Surface tension then consolidates the rim into one or more fragments which can undergo breakup depending upon the Weber number.
Another breakup mechanism, associated with higher initial Weber numbers (100<We), has also been observed in these nozzles. This mechanism is termed "stripping" ("sheet stripping" and "wave crest stripping" are examples) and occurs when a droplet deforms in a manner nearly opposite to "bag breakup". The drop flattens on the downstream side and presents a convex surface to the flow. Depending on the relative velocity and physical properties of the liquid, the edges of the deformed drop elongate into sheets and fine filaments or drops which later detach.
Examination of unconsolidated powders collected during spray forming with linear converging/diverging nozzles provides insight into the breakup mechanisms taking place. Normally an abundance of spherical or near-spherical shapes are found, as the SEM photograph in FIG. 8 illustrates. Other shapes have been observed, however. For example, the intermixing of prolate ellipsoidal particles with fine spherical tin particles in FIG. 9 suggests that the former resulted when liquid tin filaments, generated during "bag breakup" or "stripping", solidified in-flight The irregular powder shapes shown in FIG. 10 were formed using the same nozzle but at low gas flow rates. These large, irregular shapes are suggestive of parent droplets which began to undergo "bulgy" deformation and breakup but which were frozen in-flight. The bulges and protuberances appear larger than expected if due solely to solidification shrinkage.
In general, conditions which favor the formation of a narrow-droplet size distribution and a small, average droplet size are preferred in most spray-forming applications. The size distribution of high purity (99.8% by wt.) tin powders collected during spray-forming experiments has been evaluated using wet and dry sieving techniques. The powder was produced using a bench-scale linear converging nozzle of our own design having a 6° inlet and a transverse throat width of 17 mm. The nozzle, which was machined in-house from boron nitride stock, was operated at a pressure of 207 kPa (30 psia) with argon, heated to about 300° C. as the atomizing gas Liquid tin was super-heated about 70° C. above its melting point and pressure-fed into the nozzle through a series of liquid orifice holes that spanned the width of the nozzle. The driving pressure of the liquid was about 2.5 psia greater than ambient. The gas-to-metal mass ratio was measured to be about 10 with a metal throughput of about 0.5 kg/s per meter of nozzle throat width. The powder was collected in a chamber, passivated, and size analyzed by sieving through fine mesh screens of 300, 250, 210, 150, 125, 90, 75, 63, 53, 38, 25, 18, 15, 10, and 5 μm. Few particles larger than 125 μm were observed.
FIG. 11 is a histogram plot that gives the count frequency distribution versus powder size. The ordinate gives the count frequency normalized for the sieve size range, expressed as a percentage of the total counts. The plot indicates that about 85% of the powder particles were <5 μm in diameter. The average particle size was calculated to be 4 μm. The plot in FIG. 12 is a histogram plot that relates mass frequency to powder size for the same tin powder sample, again normalized for the size range of the sieves. When compared with FIG. 11, this distribution reflects the significance of the mass weighting factors (which go as d 3 ) imposed by relatively small numbers of more massive particles. Since most spray-forming applications are mass intensive, the distribution in FIG. 12 is a more representative description of the powder (and spray plume) size distribution. The Sauter (or area) mean diameter, d sm , and volume mean diameter, d w , were calculated to be 23 μm and 31 μm, respectively, using the following equations: ##EQU2## d sm is particularly useful in evaluating droplet sizes for surface area intensive processes, such as evaporation and heat transfer. It is sensitive-to-finer droplets while d vm is sensitive-to-coarser droplets. Together they give a balanced view of the powder size. The mass median diameter, d m , was determined to be 23 μm by interpolation of the cumulative weight versus size data. It is the diameter corresponding to 50% cumulative weight (d 50 ). The geometric standard deviation, σ v =(d 84 /d 16 ) 1/2 , was calculated to be 1.5, indicating a narrow-droplet size distribution in the spray plume.
In addition to controlling droplet size and shape, as described above, the present invention can be used to control droplet velocity in the spray jet. FIG. 13 gives an example. The plot gives the velocity of a 20 μm tin droplet as a function of distance from the exit of the nozzle for various nozzle pressures. The data was calculated for the converging-diverging nozzle illustrated in FIGS. 2 and 4. The tin was super-heated to 300° C. and sprayed, using argon, into a chamber with a back pressure of 12.5 psia. The spray jet entrained room temperature argon. Higher back pressures would result in more rapid deceleration of the droplets in the spray jet. Lower back pressures would result in less rapid deceleration of the droplets.
The present invention can also be used to control droplet temperature (and heat content) in the spray jet. FIG. 14 illustrates one example. The plot gives the temperature of a 20 μm tin droplet as a function of distance from the exit of the nozzle for various liquid metal temperatures. The data was calculated for the converging/diverging design of FIGS. 2 and 4. Argon gas was used at a nozzle pressure of 30 psia and a back pressure of 12.5 psia. The spray jet entrained room temperature argon. Higher back pressures, lower entrained gas temperatures, or the use of an entrained gas with a larger thermal diffusivity (e.g., helium) would result in more rapid cooling of the droplets.
The present invention can also be used to control the shape of the spray jet by engineering the shape of the flow channel of the nozzle, particularly the exit portion, or by inducing turbulence in the spray jet. For example, under similar operating conditions, spray jets produced using a converging/diverging nozzle with a small exit angle exhibit less divergence than spray jets produced with nozzles having large divergence angles. Nozzle gas velocity, mass loading, and back pressure also influence the spray jet's flow pattern and, hence, the shape of the deposit. In general, high gas velocities, low mass loadings, and low back pressures favor the formation of a more collimated spray jet. A deposit onto a flat surface is generally more gaussian (less flat) under these conditions. On the contrary, low gas velocities, high mass loadings (high liquid-to-gas mass ratios), and high back pressures favor the formation of spray jets with wider divergences. Deposits onto flat surfaces formed under these conditions are flatter having a truncated gaussian or very flat profile in cross-section. Mass loading can have a very significant effect in this regard. The liquid droplets can cause significant turbulence in the multiphase flow behavior which can result in significant divergence of the spray jet. This phenomena is favorable if the goal is to spray-form flat metal, polymer, or composite strip.
Control of these spray properties (particle size, particle size distribution, velocity, particle temperature (heat content), flux, and flow pattern) is important in spray forming since the characteristics of the spray-formed product depends on these properties and those of the substrate. FIG. 15 is a photomicrograph (400×) of a tin deposit spray formed onto a room-temperature polyethylene substrate using the method and apparatus of the present invention. It is an example of the fine-grained equiaxed microstructures that can be produced--much finer than the cast tin microstructure shown in FIG. 16 (also 400×).
Examples Of The Use Of The Present Invention For Spray-Forming Other Materials
Polymers
The conditions described below were used to form thin, uniform polymer (linear polyphosphazene (PPOP)) deposits. Due to the chemical stability of the polymer, atmosphere control was relaxed and the polymer was sprayed in air using argon as the atomizing gas.
Near-net-shape deposits of PPOP were formed by directing a spray of atomized droplets of the polymer dissolved in tetrahydrofuran (THF) onto glass substrates. The spray was generated using a linear converging/diverging nozzle of our own design machined from commercial boron nitride rod. The nozzle had an entrance and exit angle (included angle) of 14°, a throat width of 0.66" transverse to the flow direction, and a throat height of 0.094". Seven percent (by weight) solution of linear (PPOP) in THF was sprayed. The weight average molecular weight of the polymer was measured to be about 750,000 amu by gel permeation chromatography. Five-percent and three-percent solutions having a polymer weight-average molecular-weight exceeding one million amu were also sprayed but were found to give less satisfactory results. The solution was warmed to 45° C. to lower its viscosity and fed into the nozzle operating at a static pressure of 137 kPa (20 psia). The solution was aspirated through six small orifices that spanned the width of the nozzle. Solution throughput was about 0.4 Kg/sec per meter of nozzle throat width. The corresponding gas-to-polymer solution mass ratio was about 4. The solution was sheared and atomized, resulting in very fine droplets that were entrained by the gas stream and transported to a moving glass substrate. Solvent molecules were shed from the atomized particles during their flight, and the remainder of the solvent evaporated at the substrate. While control of atomizing gas temperature provided a convenient vehicle for adjusting the evaporation rate of the solvent, room temperature argon was used because the equilibrium vapor pressure of THF (145 torr at 20° C.) was high enough to allow facile evaporation of the solvent. Upon impacting the substrate, individual polymer molecules within adjacent droplets interwove while shedding any remaining solvent.
The polymer/solvent spray was deposited onto 8.3 cm×8.3 cm glass plates, maintained at room temperature. The plates were swept through the spray plume to yield deposits 1 to 10 μm thick. A typical deposit covered the glass plate to a thickness of about 5 μm and was fully dried and consolidated in only about 1 sec.
SEM analysis was used to evaluate the polymer deposit's surface structure and thickness. An example is given in FIG. 17. Over the width of the glass plates the deposit appeared homogeneous and of uniform thickness. Close examination revealed that the deposit was asymmetric, with a thin, dense region at the substrate/deposit interface and a relatively thick, uniform build-up of translucent, "spongy" polymer material away from the substrate.
Particulate Reinforced Metal Matrix Composites
Metal matrix composites (MMCs) combine metallic properties, such as high thermal and electrical conductivity, toughness, and thermal shock resistance, with ceramic properties, such as corrosion resistance, strength, high modulus, and wear resistance. The partitioning of these properties depends on the choice and volume fraction of ceramic and metal, but usually the improved properties come at some cost, such as loss of ductility and toughness relative to the matrix material. A variety of casting and powder metallurgical processing methods for particulate reinforced metal matrix composites have become available over the last two decades, and these efforts have spawned several commercial products. The development of efficient processing technologies, however, remains the greatest roadblock to large-scale commercial use of particulate-reinforced metal matrix composites. In a recent workshop sponsored by the Office of Naval Research, processing was found to be the most important area for current research and development of MMCs. Innovative development was found to be urgently needed in near-net-shape production technologies, in particular, in semifinished shapes (rods, tubes, and strip).
Spray-forming provides a unique processing approach for particulate reinforced MMCs by offering flexibility and control of particulate volume fraction together with inherent near-net-shape and rapid solidification fabrication capabilities. Process flexibility and a reduction in the number of unit operations translates to substantial savings in time, capital equipment, and energy. The present invention provides a novel approach for producing particulate reinforced MMCs which can be seen in FIG. 20. The reinforcement phase is pressure fed into the nozzle in the form of an aerosol upstream of the entry location of the molten metal at 88. Pressurizing means 92 pressurized the solid particle reservoir 94 to discharge the aerosol gas and powder via conduit means 96 into nozzle entry 88. The particulate enters the nozzle at or near room temperature but is quickly heated by the atomizing gas to the desired temperature. The liquid metal is heated about 100° C. above its liquidus temperature, pressure fed into the nozzle, atomized, and co-deposited with the reinforcement phase. Gas and liquid metal temperature control allow control of the extent of matrix/particulate wetting and interfacial reactions. The transit time of the multiphase flow to the substrate is on the order of milliseconds. Upon impacting the substrate, matrix solidification rates are expected to be high (>103K/sec), significantly restricting macrosegregation effects which are often observed in slowly cooled cast composites. This approach, therefore, largely bypasses two major problems areas experienced in most particulate reinforced MMC fabrication methods: control of matrix/particulate interfacial reactions and wetting, and non-uniform blending caused by density differences between the matrix and reinforcement phases.
Composite strip of 6061 aluminum reinforced with SiC particulate (˜13 μm diameter) was spray formed using the method and apparatus of the present invention. 6061 aluminum alloy was also sprayed without the reinforcement phase using the method and apparatus of the present invention. Particulate volume fraction in the composites ranged from 4 to 15%, as determined by acid dissolution of the matrix. Optical microscopy of polished samples indicated a uniform distribution of particulate in the matrix phase; an example is given in FIG. 17. As-deposited density of the matrix strip, measured by water displacement using Archimedes' principle, was 90 to 95% of theoretical. Photomicrographs of polished samples, however, revealed that as little as 30% thickness reduction was needed for full densification of both the composite and pure 6061 alloy materials.
As-deposited composite strip was sectioned and hot rolled at 450° C. to 80% thickness reduction. Samples were then heat treated to yield a -T6 temper. Room-temperature tensile properties were evaluated for eight samples. The composite material had small but significant (about 10%) improvements in ultimate and yield strength over commercial 6061-T6 strip, but a reduction in elongation. Ultimate tensile strength, yield strength, and elongation were as high as 337 MPa, 308 MPa, and 9.5% respectively, in the spray formed and hot rolled composite strip. The tensile strength of commercial 6061-T6 aluminum strip is typically about 310 MPa, with a yield strength of 275 MPa, and an elongation of 12%. While these preliminary results are encouraging, evaluation of a larger number of test samples is necessary to establish statistical validity.
In conclusion, then, the present invention comprises a means and method for pressurized feed-injection of molten metals, polymers, or metal/polymer matrix composites into a pressurized gas flow which atomizes and accelerates the molten metal droplets toward a desired substrate. The present invention is an improvement over the aspiration method disclosed in Alvarez.
These improvements occur because the present invention decouples the atomization and aspiration functions of the patented design, resulting in greater spray-nozzle design flexibility and enhanced atomization efficiency. Other experimentally verified improvements include: the ability to pressure-feed liquids into the nozzle at rates independent of gas flow conditions; the ability to utilize higher nozzle pressures and higher gas-flow rates; the ability to locate the liquid orifice(s) anywhere along the length of the nozzle or anywhere within the gas-flow channel; the use of smaller liquid orifice(s) for a given liquid throughput; the use of nozzle designs that improve the pattern of the multiphase flow field; and the use of the device for producing particulate reinforced and other composites.
The aspiration method is limited to a converging/diverging design. The present invention covers converging as well as converging/diverging designs. This allows the use of gas flow channels that improve the spray pattern.
In the aspiration method, two liquid-feed methods are described: "orthogonal" and "in-line". In both cases the liquid enters the flow channel of the nozzle "at or near the choke point", i.e., the nozzle's throat This is an important difference between the two designs. The pressurized feed nozzle design allows the liquid to be fed into the nozzle anywhere within the flow channel and anywhere along the length of the nozzle, including upstream or downstream of the throat as shown in FIGS. 2 and 4 of the present invention.
Operation of the aspiration method nozzle is limited to a narrow range of operating parameters. Use of a pressurized feed allows the nozzle to be operated at virtually any nozzle pressure and gas flow rate. This is significant because atomization of a given liquid improves as the relative velocity between the liquid and the gas increases. Higher nozzle pressures and, hence, higher gas velocities are possible with the pressurized feed nozzle. Moreover, the pressurized feed nozzle allows independent control of the liquid's flow rate and the nozzle operating pressure.
The present nozzle design allows liquid-feed rate and nozzle pressure (nozzle gas-flow rate) to be completely independent. This allows the use of higher gas velocities and smaller liquid-inlet orifice(s) for better atomization.
In the aspiration method, described in U.S. Pat. No. 4,919,853, it is stated, "An important aspect of the supersonic nozzle of the subject invention is the ability to control the shape of the exiting spray. When the exit pressure equals the ambient pressure, the spray maintains the same cross section as the nozzle exit. When the exit pressure is lower, the spray converges and when the exit pressure is higher the spray diverges." In general, this simple one-to-one correspondence between exit pressure and spray shape is not observed with the present invention.
The invention described in U.S. Pat. No. 4,919,853 does mention feeding two liquids into the nozzle from separate liquid feeds (col. 6, line 25). However, there is no mention of feeding solid particulate, whiskers, or fibers into the nozzle and co-depositing the material with metal or polymers to form metal or polymer matrix composites.
While a preferred embodiment of the invention has been disclosed, various modes of carrying out the principles disclosed herein are contemplated as being within the scope of the following claims. Therefore, it is understood that the scope of the invention is not to be limited except as otherwise set forth in the claims.
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A spray apparatus and method for injecting a heated, pressurized liquid in a first predetermined direction into a pressurized gas flow that is flowing in a second predetermined direction, to provide for atomizing and admixing the liquid with the gas to form a two-phase mixture. A valve is also disposed within the injected liquid conduit to provide for a pulsed injection of the liquid and timed deposit of the atomized gas phase. Preferred embodiments include multiple liquid feed ports and reservoirs to provide for multiphase mixtures of metals, ceramics, and polymers.
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FIELD OF THE INVENTION
The present invention relates in general to a handloom and pertains, more particularly, to the use of a supplementary beater that is manipulated in association with the weaving procedure.
BACKGROUND OF THE INVENTION
By way of example, reference may be made to U.S. Pat. No. 4,195,670 to Orr et al. for the description of a handloom that is of a type usable with a reed device. As will be described in further detail hereinafter, a reed is a comb-like device through which the warp threads are threaded to maintain the warp threads in a spaced apart relationship. A beater is used for holding the reed and is in the form of a movable frame (beater) which regulates the density of weft. The typical handloom is for creating woven fabrics. For this purpose, the beater is transitioned so as to firmly engage a weft yarn with the warp yarns. However, this normal loom function does not enable any variance in the weft yarn patterns.
Accordingly, it is an object of the present invention to provide a supplementary beater that is adapted for manual insertion into the shed and for the purpose of providing an undulating weft pattern in the fabric weave.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a handloom for constructing a fabric weave and that includes a warp beam, a harness for supporting and controlling warp threads, a reed defining a shed and disposed adjacent to the harness for supporting warp threads, and a shuttle for passing weft threads, one at a time, into the shed. The improvement in accordance with the present invention is comprised of a supplementary beater adapted for manual insertion into the shed and for the purpose of providing an undulating weft pattern in the fabric weave.
In accordance with other aspects of the present invention the supplementary beater is elongated, having opposed elongated side edges; one of the side edges has an undulating surface edge; the opposed side edge is straight; the undulating surface extends along a center section of the supplementary beater; the undulating surface edge has straight edges on either side thereof; both edges of the supplementary beater have a pointed cross-section; one of the side edges has a saw tooth shape; one of the side edges has a square tooth shape.
In another version of the present invention there is provided a method of using a handloom for constructing a fabric weave and that includes a warp beam, a harness for supporting and controlling warp threads, a reed defining a shed and disposed adjacent to the harness for supporting warp threads, and a shuttle for passing weft threads, one at a time, into the shed, The method comprises providing a supplementary beater and manually inserting the supplementary beater into the shed and for the purpose of providing an undulating weft pattern in the fabric weave. This method may also include moving the supplementary beater in a direction transverse to the warp thread direction to alter the undulating weft pattern. This method may also include the supplementary beater being automatically controlled to control the undulating weft pattern.
BRIEF DESCRIPTION OF THE DRAWINGS
It should be understood that the drawings are provided for the purpose of illustration only and are not intended to define the limits of the disclosure. In the drawings depicting the present invention, all dimensions are to scale. The foregoing and other objects and advantages of the embodiments described herein will become apparent with reference to the following detailed description when taken in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view of a supplementary beater construction in accordance with the principles of the present invention;
FIG. 2 is a fragmentary perspective view showing the undulating surface of the supplementary beater;
FIG. 3 is a plan view of the supplementary beater;
FIG. 4 is an enlarged fragmentary plan view of the supplementary beater;
FIG. 5 is a cross-sectional view taken along line 5 - 5 of FIG. 4 ;
FIG. 6 is a perspective view of a handloom and depicting various components thereof;
FIG. 7 is a fragmentary perspective view of a portion of the handloom showing the step of inserting the shuttle;
FIG. 8 is a fragmentary perspective view showing a reinsertion of the shuttle;
FIG. 9 is a schematic side view of a portion of the handloom illustrating the weft thread being inserted into the shed;
FIG. 10 illustrates a single one of the warp yarns positioned relative to the weft yarns;
FIG. 11 is a fragmentary perspective view illustrating the use of the supplementary beater of the present invention;
FIG. 12 is a side view similar to that illustrated in FIG. 9 but also illustrating the supplementary beater in position within the shed;
FIG. 13 is a schematic diagram illustrating the supplementary beater in the manner in which it is altering the position of the weft yarn;
FIG. 14 is a plan view of further steps taken by the supplementary beater to vary the weft yarn patterns;
FIG. 15 is a photograph of the weft yarn configuration; and
FIGS. 16 and 17 illustrate alternate embodiments of the supplementary beater.
DETAILED DESCRIPTION
Reference is now made to FIGS. 1-5 of the present application for an illustration of the supplementary beater that is used in the procedure with a handloom such as the one illustrated in FIG. 6 herein. Thus, in FIGS. 1-5 there is illustrated a supplementary beater 10 that is elongated in shape having opposed elongated sides 10 A and 10 B. The side 10 A is substantially straight as illustrated in the drawings while the side 10 B has an undulating surface as noted in the drawings. Also, each of these opposed sides are illustrated in the cross-sectional view of FIG. 5 as being somewhat pointed. In addition to the supplementary beater being elongated, it is substantially flat with flat opposed sides 10 C and 10 D as illustrated in the cross-sectional view of FIG. 5 . The supplementary beater illustrated in FIGS. 1-5 may be used to create the weft yarn pattern such as illustrated in FIG. 15 herein.
Reference may also be made to alternate supplementary beater configurations as illustrated in FIGS. 16 and 17 . FIG. 16 illustrates more of a sawtooth-type undulating pattern. The supplementary beaters illustrated in FIGS. 16 and 17 may be of basically the same constructions as illustrated in FIGS. 1-5 with the exception of the configuration of the undulating surface. In FIG. 17 the undulating surface has a trapezoidal configuration.
Reference is now made to the perspective view of FIG. 6 for an illustration of a handloom. Because the various components of the handloom are well known, the components are not described in great detail herein. The handloom 20 includes, for example, a breast beam 22 at one end and a back beam 24 at the other end; a beater 26 that supports the reed 28 ; and the harness 30 . Associated with the beater 26 is the shuttle race 32 . In FIG. 6 , for the sake of simplicity, none of the yarns are illustrated. However, reference may now be made to, for example, FIGS. 7 and 8 for an illustration of a portion of the handloom particularly at the beater 26 .
The handloom holds the threads, known as warp threads or ends in a taut condition. These warp threads are raised or lowered to form a shed 25 , or opening through which the weft, or filler threads is inserted to create an interlacement or fabric. The warp threads are controlled by means of heddles at the harness 30 . Thus, the handloom is comprised of a framework to hold warp threads rigid while the weft thread is interlaced.
The beater is a movable frame that holds the reed, which orders the warp yarns and regulates the density of the weft yarns. By pulling the beater forward, it pushes the weft into place against the warp yarns. The beater is attached to either the top or bottom of the loom by a pair of upright battens which allow it to swing freely. After each new pick of weft has been passed through the shed, the beater is normally pulled against the web in such a way that the reed packs the new weft against the previous weft.
The reed 28 is a comb-like device that is parallel to the harnesses and through which the warp ends are threaded after they leave the heddles. The reed is supported by the beater to space the warp ends according to the desired weave. The reed may be provided in a variety of spacings, lengths and heights depending upon the construction of the particular hand loom. The shed is an opening through which the weft is inserted to create interlacement or fabric. The shed is formed by lowering or raising the warp threads.
Reference is now made to the fragmentary perspective view of FIG. 7 which shows the sets of warp threads 40 . FIG. 7 also illustrates the beater 26 and the shuttle 34 being held in the hand of the user and supporting a single weft thread 36 . FIG. 7 illustrates the shuttle 34 about to be placed into the shed 25 between warp threads. FIG. 8 illustrates the shuttle 34 emerging from the shed 25 .
Reference is now made to the schematic side view of FIG. 9 which illustrates a portion of the handloom. This illustrates the weft thread 36 disposed within the shed 25 as previously illustrated in FIGS. 7 and 8 . FIG. 9 also shows the harness 30 and its supported heddles. Reference may also be made to the plan view of FIG. 10 showing the warp threads at 40 and the interlaced weft thread 36 .
Reference is now made to the fragmentary perspective view of FIG. 11 for an illustration of the use of the supplementary beater 10 previously illustrated in FIGS. 1-5 . In FIG. 11 , the supplementary beater 10 is illustrated as inserted into the shed 25 between sets of warp threads 40 . It is positioned so that the undulating surface 10 B faces the previously inserted weft thread 36 . FIG. 11 illustrates the supplementary beater 10 about to be moved in the direction of arrow A to engage and position the illustrated weft thread 36 . Thus, the supplementary beater 10 can be moved in the direction of arrow A as well as in a transverse manner to the threads 40 such as in the direction of arrow B in order to alter the configuration of the weft thread 36 . In this regard refer also to the side schematic view of FIG. 12 that illustrates a position of the supplementary beater 10 relative to the weft thread 36 .
Reference is now also made to the plan view of FIG. 13 for an illustration of the supplementary beater 10 as moved in the direction of arrow A within the shed 25 . FIG. 13 illustrates the undulating surface 10 B of the supplementary beater forming an undulation in the thread 36 so that the placement of the thread 36 essentially matches in contour the contour of the undulating surface 10 B of the supplementary beater 10 . In this regard refer also to the plan view of FIG. 14 that shows the supplementary beater 10 engaging with a weft thread 36 . The diagram of FIG. 14 illustrates the manner in which the supplementary beater 10 may be moved both in the direction of arrow A but also possibly transversely in the direction of arrow B so as to alter the undulating pattern. FIG. 14 illustrates a series of weft threads at 36 A. It can be seen there that these threads have different undulating configurations which are a function of the particular placement and movement of the supplementary beater 10 as each weft thread is engaged thereby. Refer also to the diagram of FIG. 15 which is a photograph illustrating the various weft threads at 36 and the corresponding warp threads 40 . It can be seen from FIG. 15 that the weft threads, as controlled from the manipulation of the supplementary beater, become disposed in different undulating patterns. This provides a totally unique fabric configuration.
Having now described a limited number of embodiments of the present invention, it should now be apparent to those skilled in the art that numerous other embodiments and modifications thereof are contemplated as falling within the scope of the present invention, as defined by the appended claims.
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A supplementary beater used with a handloom for constructing a fabric weave, and an associated method of use thereof. The handloom includes a warp beam, a harness for supporting and controlling warp threads, a reed defining a shed and disposed adjacent to the harness for supporting warp threads, and a shuttle for passing weft threads, one at a time, into the shed. The supplementary beater is adapted for manual insertion into the shed and for the purpose of providing an undulating weft pattern in the fabric weave.
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Genus: Vitis (complex interspecific hybrid lineage).
BACKGROUND AND SUMMARY OF THE INVENTION
The new grape plant named ‘Improved Chancellor’ is of Vitis parentage, with the breeding chart tracing the lineage as shown in FIG. 3 .
The new grapevine resulted from stably introducing a plant expressible tfdA gene from Ralstonia eutrophus into Chancellor grapes. The tdfA gene confers resistance in plants to the phenoxy herbicides, especially 2,4 D (2,4-diphenoxyacetic acid). For a general discussion, see U.S. Pat. Publication No. 2003-0154507. This resistance improves the performance of grapevines, which are by nature exquisitely sensitive to the phenoxy herbicides, with deleterious effects observed with drift of herbicide from fields in the area, especially grain fields sprayed to control broadleaf weeds. Damage from drift negatively affects growth and/or yield in affected vineyards.
DESCRIPTION OF THE INVENTION
The transgenic 2, 4-D resistant ‘Chancellor’ grape was produced via genetic engineering. Embryogenic callus was initiated from ovary explants dissected from flower buds 10-14 days before anthesis on Nistch and Nistch (1969) medium containing 9 μM 2, 4-D, 17 μM IASP, and 1 μM BAP in darkness. Embryogenic callus was proliferated and maintained in NN medium containing 2 μM 2, 4-D, 0.2 μM TDZ and 4 μM IASP (Long Term Maintenance Medium, LTMM). Embryogenic callus cultivated for 5 weeks in LTMM was infected with Agrobacterium tumefaciens strain LBA4404:pAL4404 carrying a pBIN19 plant transformation plasmid vector containing the tfdA gene construct. The 864 bp tfdA gene in the construct is driven by the CaMV35S core promoter and linked to the nos gene terminator. Transformed embryogenic cells were selected on LTMM containing 350 mg l −1 kanamycin and induced to develop somatic embryos on NN medium supplemented with 10 μM IASP, 8 μM NOA, 1 μM TDZ, 1 μM ABA and 2.5 g l −1 activated charcoal (Embryo Development and Maturation Medium, EDMM). Somatic embryos were germinated and converted into plantlets in ½ MS (Murashige & Skoog, 1962) medium containing 0.5 μM BA+0.025 μM NAA. PCR analysis of regenerated plantlets with tfdA-specific primers showed they contained the tfdA gene. The expression of the tfdA gene in the transgenic plants was demonstrated by their 2, 4-D resistance during spray tests. Transgenic plants survived treatment with 0.5, 5, and 10 kg ha −1 of 2-ethylhexyl ester of 2, 4-D. These rates killed non-transgenic plants.
Spray tests utilized applications of 2,4D corresponding to field application rates of 0, 0.5, 5 and 10 kg/ha of a commercial herbicide preparation (LV400, Growmark Inc). After spraying, the transgenic plant and wild type plants were allowed to dry and then transferred to an isolation greenhouse, and they were observed for damage over a period of three weeks. The wild type plants showed signs of damage within two hours of spraying and they were all dead within one week. While the transgenic plant showed minor, short lived injury (leaf epinasty) for up to seven days at the 2 higher doses of 2 4-D, there was full recovery, with normal growth at the end of two weeks.
The original vine of ‘Improved Chancellor’ arose from selection among embryogenic cells developed in vitro. The cells had been transformed with the tfdA gene. About 20 plants were regenerated between 2002 and 2003; ‘Improved Chancellor’ was selected from these. It was then micropropagated by cuttings in Urbana, Ill. Those resulting plants were stable and typical of the original vine. ‘Improved Chancellor's’ resistance to 2,4-D was confirmed in 2004 in the original plant and in asexually propagated material from the original plant. Subsequent asexual propagations of the variety have also proven stable with true to type plants.
COMPARISON WITH PARENTAL CULTIVAR
The new grape plant named ‘Improved Chancellor’ resembles the parent grape, from which it was produced by genetic modification, but it differs in that it is significantly less sensitive to herbicide 2,4-D. The fruit color, flavor and texture is expected to be similar to the original grape. Vigor of the new variety is the same as the parent plant in absence of herbicide. However, vigor of ‘Improved Chancellor’ is increased over that of the parent plant in the presence of herbicide.
DESCRIPTION OF THE FIGURES
FIG. 1 Shows canes, leaves, and tendrils of ‘Improved Chancellor’ (left) in comparison to the parent (right)
FIG. 2 Shows fruit clusters of parental ‘Chancellor’ at harvest.
FIG. 3 Shows the breeding chart tracing the lineage of ‘Improved Chancellor’.
DETAILED BOTANICAL DESCRIPTION OF THE INVENTION
The following description of grapevine contains references to color names taken from the Ridgeway Color Standards and Color Nomenclature (1912, Hoen and Co., Baltimore, Md.). Descriptors used herein conform to those set forth by the International Board for Plant Genetic Resources Institute Grape Descriptors ( Vitis spp.) of 1983 and/or 1997 which were developed in collaboration with the Office International de la Vigne et du Vin (OIV) and the International Union for the Protection of New Varieties of Plants (UPOV) and published in Descriptors for Grapevine ( Vitis spp.) (Anonymous, International Plant Genetic Resources Institute, 1997, ISBN 92-9043-352-3).
Descriptions of the new invention apply to vines of ‘Improved Chancellor’ grown in an isolation greenhouse in the year 2005. These vines were in their first year of growth having been transplanted from in vitro to the greenhouse in December 2004. The parent clones (control) were growing on their own roots in Urbana, Ill. The descriptions of the parent plants apply generally to the new variety grown under similar circumstances elsewhere:
VINE
General:
Vigor.— Too young to give valid data. Productivity.— Unavailable. Hardiness.— Unavailable. Rootstock.— None.
LEAVES
Mature leaves: Average blade length 8.6 cm. Average blade width 12.5 cm.
Size of blade.— Large. Shape.— Pentagonal. Anthocyanin coloration of main veins on the upper side of the blade. Present at base of veins on mature leaves, Dahlia Purple, 67.V-R.m Plate XII. Anthocyanin coloration of main veins on lower leaf surface.— Clear Yellow Green, 31.Y-G. Plate VI. Mature leaf profile.— Undulating. Blistering surface of blade upper surface.— Absent. Leaf blade tip.— Curved downward. Margins.— Serrate. Apex.— Acuminate. Base.— Sagittate. Thickness.— 0.06552 in. Undulation of blade between main and lateral veins.— Medium. Shape of teeth.— Conical, both sides convex. Length of teeth.— 3.8 mm. Ratio length/width of teeth.— About 1:1.6. General shape of petiole sinus.— Y-shaped. Tooth at petiole sinus.— Absent. Petiole sinus limited by veins.— Absent. Shape of upper lateral sinus.— Open Y-shaped. Prostrate hairs between veins on lower surface of blade.— Absent. Erect hairs between veins on lower surface of blade.— Absent. Prostrate hairs on main veins on lower surface of blade.— Present. Density of erect hairs on main veins on lower surface of blade.— Sparse. Prostrate hairs on main veins on upper surface of blade.— Absent.
Upper surface:
Summer color.— Civette green, 31′ Y-G. Plate XVIII. Autumn color.— Variety's Green, 31′. Y-G Plate XVIII. Surface texture.— Smooth. Surface appearance.— Medium glossy. Goffering of blade.— Medium on mature leaves.
Lower surface:
Summer color.— Mineral green, 31′. Y-G. i Plate XVIII. Autumn color.— Grass Green, 33. G-YG Plate VI. Anthocyanin coloration of main veins on lower leaf surface.— Clear Yellow Green, 31. YG Plate VI. Glossiness.— Low. Pubescence.— Mildly present. Surface texture.— Medium leathery. Surface appearance.— Dull.
Petiole:
Length of petiole.— 5.8 cm — mean of 10 petioles. Diameter.— 2.2 mm — mean of 10 petioles. Fall color.— Varies along petiole from Deer Rose Pink, 71. V-RR. Plate XII) to Amaranth Purple, 69. Rv-R Plate XII. Length of petiole compared to middle vein.— In fall petioles are about 50% to 100% longer than the vein. Density of prostrate hairs on petiole.— Sparse on young leaves; absent on mature leaves. Density of erect hairs on petiole.— Dense on young leaves. Shape of base of petiole sinus.— Mostly open, with inside outline ovate.
TENDRILS
Number.— Tendrils at all nodes above node #2; abort on older growth. Length.— 14.8 cm. Diameter.— 1.4 mm. Texture.— Smooth. Color.— Mineral green, 31′. Y-G. i Plate XVIII, with occasional Brown vinaceous, 5′″.OO-R Plate XXXIX to Pale Veronese Green, 31′. Y-G, Plate XVIII.
WOODY SHOOT
Trunk:
Trunk circumference.— 0.4 cm. at 1 meter height. Mean of 10 plants. Shape.— Circular. Surface texture.— Smooth — canes still young. Outer bark color.— Vinaceous Tawny, 11″ orange Plate XXVIII.
Canes:
Shape of canes in cross section.— Broadly elliptical. Internode length.— 6.7 cm. Mean of 10 canes counting nodes #3-6. Width at node.— About 0.75 cm. Mean of 10 canes measuring nodes #3-6. Surface.— Smooth. Main color.— Bright Clalcedony Yellow, 25′ YG-Y-i Plate XVII. Fall color.— Carob brown, 9′. OR-O Plate XIV. Lenticels.— Inconspicuous. Erect hairs on nodes.— Absent. Erect hairs on internodes.— Absent. Growth of axillary shoots.— Moderately prolific. Shape of nodes in cross section.— Circular to broadly elliptical. Number.— Lateral shoots generally develop at all nodes above node #5. Length.— Grow to about 0.5 to 1 m. Diameter.— 2.9 mm — mean of 10 laterals. Internode length.— 6.3 cm — mean of 10 canes. Color.— Wintergreen, 33′.GY-G, Plate XVIII to Dark Maroon Purple, 71′.V-RR, Plate XXVI.
Buds:
Shape.— Conical. Length.— 2.8 mm. — mean of 9 buds node. Width.— 3.2 mm. mean of 9 buds node. Color.— Vinaceous Tawny, 11″ orange Plate XXVIII.
FLOWERS — Data from mature field parent ‘Chancellor’ plants
General:
Flower sex.— Perfect. Length of first inflorescence.— 5.2 cm. — Mean of 7 inflorescences. Position of first flowering nodes.— 2-4. Number of inflorescences per shoot.—# 1 TO 2. Pedicel length.— 2.3 mm. — Mean of 10 pedicels. Calyptra color.— Light Turtle green, 31″. Y-G Plate XXXII. Ovary length.— 1.5 mm. — Mean of 10 ovaries. Ovary width.— 1.2 mm. — Mean of 10 ovaries. Ovary color.— Light fluorite green, 33″.GY-G., Plate XXXII. Filament length.— 1.9 mm. Composite mean of single filaments each from 5 flowers. Filament color.— Pale Turtle Green, 31″. Y-G Plate XXXII. Anther length.— 0.55 mm. Composite mean of 4 anthers each from 4 flowers. Anther color.— Cream color 19′.YO-Y. f Plate XVI.
FRUIT
Herbicide resistance: Significantly greater resistance to phenoxy herbicides (especially 2,4 diphenoxyacetic acid) than parent ‘Chancellor’ grapevine. The resistance in the ‘Improved Chancellor’ is due to its genetic modification to contain and express the tfdA coding sequence. Transgenic plants survived treatment with 0.5, 5, and 10 kg ha −1 of the 2-ethylhexyl ester of 2, 4-D. These rates killed non-transgenic plants.
References:
Anonymous. International Plant Genetic Resources Institute, 1997, ISBN 92-9043-352-3
Murashige, T. and F. Skoog. 1962. A revised medium for rapid growth and bio-assays with tobacco tissue cultures. Physiologia Plantarum, 15: 473-497.
Nistch, J. P. and C. Nistch. 1969. Haploid plants from pollen grains. Science, 163: 85-87.
Ridgeway, R. 1912. Color standards and color nomenclature. A. Hoen and Company, Baltimore, Md.
Skirvin, R. M., M. A. Norton, A. G. Otterbacher, R. Mulwa, B. Shoemaker, B. Aly, and E. Wahle. 2005. Grape varieties for the different regions of Illinois — 2005. Proceedings 2005 Illinois Small Fruit & Strawberry Schools. NRES 7:29-40.
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A new and distinct transgenic grape plant Vitis vinifera called “Improved Chancellor” which is characterized by greater tolerance to 2,4-diphenoxyacetic acid than is the parent Chancellor grape plant.
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BACKGROUND OF THE INVENTION
The present invention relates to a tunable semiconductor laser adapted for laser oscillation at an optionally variable wavelength.
A GaAs-Ga 1-x Al x As double heterostructure distributed feedback laser diode is known as one of semiconductor lasers for effecting single longitudinal mode oscillation developed for long-distance optical transmission. The laser diode includes an active layer formed with a grating provided by a multiplicity of parallel grooves at a given spacing. The laser diode effects stable oscillation at a selected wavelength λ given by the following equation.
λ=2nΛ/m (1)
where n is the refractive index of the active layer, Λ is the spacing between the grooves of the grating, and m is the order of the Bragg diffraction. Equation (1) indicates that the wavelength λ of the laser beam emitted is dependent on the spacing Λ of the grating, hence stable oscillation, whereas the diode involves the problem that the oscillation wavelength can not be altered. The laser diode may be made wavelength-tunable by utilizing the fact that the refractive index n varies with temperature, but to vary the temperature over a wide range requires a heating or cooling device, while there aries the need to use a constant-temperature chamber or thermostat to maintain the diode at the desired temperature stably. The use of such a device is undesirable when providing the diode in the form of an integrated unit including an optical circuit and other elements. Further because the Ga 1-x Al x As cladding layer must be grown after forming the grating on the active layer, the diode is difficult to fabricate and likely to involve defects at the junction of the active layer and the cladding layer.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a tunable semiconductor laser which is adapted for stable single longitudinal mode oscillation and with which the oscillation wavelength is variable over a wide range.
Another object of the invention is to provide a tunable semiconductor laser which can be integrated with an optical circuit and other elements and which is easy to fabricate.
The tunable semiconductor laser of this invention has an active layer and means for selectively reflecting light of a specified wavelength emitted within the active layer, the reflecting means being capable of varying the wavelength of the light to be reflected and being provided on or above a portion of the active layer. Examples of useful light reflecting means are means for generating a surface acoustic wave (hereinafter referred to as "SAW") having a variable frequency, such as an interdigital transducer (hereinafter referred to as "IDT"), and means for generating SAW's of different frequencies at different locations, such as an IDT having linear electrodes at different spacings, or a plurality of Gunn diodes which are different in the spacing between the electrodes and therefore adapted for oscillation at different frequencies. Other examples of light reflecting means will be described with reference to embodiments.
The presence of the SAW produces on the active layer distributions of refractive indexes repeating at a specified spacing, and only the light of wavelength which is determined by the spacing of the distributions is reflected selectively, so that laser oscillation occurs at the single wavelength selected. Since the frequency of the SAW is tunable and differs from location to location, a laser beam of the desired wavelength can be obtained. Because the IDT or Gunn diodes only need to be provided on or above the active layer of the semiconductor laser, the present laser is easy to fabricate and can be provided in the form of an integrated unit.
Other features and advantages of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view schematically showing an embodiment of the invention;
FIG. 2 is a perspective view schematically showing another embodiment of the invention;
FIG. 3 is a perspective view schematically showing a modification of the embodiment of FIG. 1;
FIG. 4 shows how a SAW spreads out;
FIG. 5 is a perspective view schematically showing another modification;
FIG. 6 shows an enlarged oscillation frequency bandwidth;
FIGS. 7 to 9 are plan views showing other modifications;
FIG. 10 is a perspective view schematically showing another embodiment of the invention;
FIG. 11 is a perspective view schematically showing another embodiment of the invention; and
FIG. 12 is a block diagram showing a wavelength multiplex communication system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a double heterostructure (DH structure) laser embodying the invention. As is well known, the DH structure laser is prepared by growing on an n-GaAs single-crystal substrate 1 an n-Ga 1-x Al x As cladding layer 2, a p-GaAs layer 3 serving as an active region, p-Ga 1-x Al x As cladding layer 4 and a p-GaAs layer 5 by the liquid phase epitaxy technique, forming contacts 6 on the upper and lower surfaces of the resulting structure by vacuum evaporation, and cleaving or cutting the structure to a suitable size. With this laser diode, the cleaved facets at the opposite ends provide an optical resonator, so that when a forward current is passed through the diode and exceeds a threshold value, the p-GaAs layer 3 serves as an active layer for confining light and carriers therein to emit a laser beam A.
A portion of the DH structure is cut out as by etching to partly expose the p-GaAs layer 3. An insulating film 8 of a piezoelectric material, such as ZnO, is formed on the exposed portion of the layer 3, and an IDT 9 is provided on the film 8, for example, by photolithography.
A high-frequency electric field is applied to the IDT 9 by a frequency-variable oscillator 10. This generates from the IDT 9 a SAW which propagates on the insulating film 8 in the direction of emission of the laser beam A. The SAW gives the insulating film 8 distributions of refractive indexes repeating at a specified spacing in the direction of propagation of the beam. Only the light of a wavelength determined by the spacing of the distributions is reflected, with the result that single mode longitudinal laser oscillation occurs at the selected wavelength. Assuming that the wavelength of the SAW is Λ, a laser beam is obtained which has a wavelength λ given by Equation (1). Moreover, the wavelength Λ of the SAW is variable by varying the frequency of the electric field to be applied to the IDT 9, so that the wavelength to be selected is also variable.
It is assumed that the frequency f of the electric field to be applied to the IDT 9 is varied by Δf to produce a variation ΔΛ in the wavelength Λ of the SAW. From Equation (1), the resulting variation Δλ of the oscillation wavelength λ is
Δλ=2nΔΛ/m (2)
When the velocity of propagation of the SAW is V,
V=fΛ (3)
Therefore
Δf=ΔΛ(-f.sup.2 /V) (4)
From Equations (4) and (2)
Δλ=-2nV(Δf/f.sup.2 m) (5)
For example when m is 1, V is 3300 m/s, n is 3.37, f is 20 GHz and Δf is 2 GHz in Equation (4),
Δλ=0.11 μm
Suppose the IDT 9 has an oscillation frequency of 20 GHz to give a laser beam having a wavelength of 1 μm. If the frequency is then varied by 2 GHz, the wavelength of the laser beam varies by 0.11 μm=1100 Å.
FIG. 2 shows an integrated twin guide (ITG) type laser diode embodying the invention. The diode comprises Ga 1-x Al x As cladding layers 12, 14 and 16, GaAs layers 13 and 15 serving as active layers, and a p-GaAs layer 17 which are formed over an n-GaAs substrate 11. Contacts 18 are formed on the upper and lower surfaces of the structure by vacuum evaporation. At each end of the laser, the cladding layer 14 and the overlying layers are cut out, and the exposed portion is covered with an insulating film 19. At least one of the two portions of the films 19 parallel to the GaAs layer 13 is provided with an IDT 9. Like the DH structure laser shown in FIG. 1, the ITG type laser is wavelength-tunable by varying the frequency of the driving electric field to be applied to the IDT 9.
FIG. 3 shows a modified DH structure laser embodying the invention and having an IDT 20 which differs from the IDT shown in FIG. 1 in configuration. The IDT 9 comprises a large number of parallel linear electrodes 9a, and two parallel common electrodes 9b connecting every other electrode 9a. The IDT 20 comprises linear electrodes 20a each in the form of a circular arc, and common electrodes 20b which are not in parallel but are inclined toward each other. The circular arc arrangement of the linear electrodes 20a of the IDT serves to inhibit the spreading out of the oscillation mode and the laser beam to be emitted.
With the IDT 9 shown in FIG. 4, section a and having straight linear electrodes 9a, the SAW generated propagates while spreading out through an angle θ due to a diffraction effect, consequently causing spreading out of the laser oscillation mode or laser beam. However, with the IDT 20 shown in FIG. 4, section b and having the circular arc linear electrodes 20a, the SAW propagates in a converging direction, consequently propagating substantially without spreading out even if the spreading angle θ is considered. This inhibits spreading out of the laser beam A and results in a stable oscillation mode. The light can be confined effectively to assure an improved laser oscillation efficiency, reducing the power needed for the high-frequency electric field to be applied to the IDT 20.
FIG. 5 shows another modification. An IDT 21 provided on an insulating film 8 comprises straight electrodes 21a, and the pitch (the spacing between the adjacent electrodes 21a connected to each common electrode 21b) is varied in the direction of propagation of the SAW produced. When the pitch of all the linear electrodes 9a is the same as is the case with the IDT 9 shown in FIG. 1, the tunable wavelength band is limited to a narrow range since the center wavelength of the SAW is dependent on the pitch. In the case of the IDT 21 shown in FIG. 5, however, the spacings between the electrodes 21a connected to the same electrode 21b are different in corresponding relation to the different wavelengths Λ1 to Λj of the SAW. Accordingly the wavelength of the SAW to be generated from the IDT 21 can be varied by ΔΛ as centered at each of the wavelengths Λ1 to Λj. When this is expressed in terms of the frequency f of the electric field to be applied to the IDT 21, with the frequencies corresponding to the wavelengths Λ1 to Λj represented by f1 to fj, the frequency can be varied by Δf as centered at each of the frequencies f1 to fj. Thus, when the pitches Λ1 to Λj are suitably determined, the bandwidth F of tunable frequencies is j times the bandwidth in the case where the pitches are equal, namely F=j·Δf, as illustrated in FIG. 6. It therefore follows that when the oscillation wavelengths of the DH structure laser are λ1 to λj in corresponding relation to the frequencies f1 to fj, the laser oscillation wavelength can be varied by Δλ of Equation (5) as centered at each of λ1 to λj. Thus the oscillation wavelength of the tunable semiconductor laser is variable over the wide range of j·Δλ.
FIG. 7 shows another modification, wherein linear electrodes 22a to 22c having different pitches are arranged in a direction at right angles to the direction of emission of the laser beam to provide an IDT 22. The laser produces beams having different wavelengths λ1 to λj (j=3) at different beam emitting positions.
FIG. 8 shows another modification, wherein three kinds of circular-arc linear electrodes 23a to 23c, different in pitch, provide an IDT 23. The electrodes are connected together. Since the SAW's generated from such circular-arc linear electrodes tend to converge as already stated, the laser beam emitted is prevented from spreading out.
FIG. 9 shows still another modification, wherein an IDT 24 comprises circular-arc linear electrodes having a continuously varying pitch. In this case, the wavelength of the laser beam emitted varies with the position of emission, and the beam converges at a point. This faciliates optical coupling, for example, to an optical fiber.
With the modifications of FIGS. 5 and 7 to 9, d.c. voltage can be applied to the IDT because distributions of refractive indexes are then produced immediately therebelow.
FIG. 10 shows another embodiment. The DH structure laser shown is provided with an array 25 of Gunn diodes 25c formed on an insulating film 8 and arranged as insulated from each other in a row at right angles to the direction of emission of a laser beam. The spacing between electrodes 25a and 25b differ from diode to diode. One of the Gunn diodes 25c of the array 25 is selectively driven by a change-over switch 26 to generate from the selected Gunn diode a SAW propagating on the film 8 in the direction of emission. As already stated, single mode laser oscillation occurs at a wavelength selected in accordance with the wavelength of the SAW. The wavelength of the SAW is selectively determined by selectively driving one of the Gunn diodes which differ in the spacing of the electrodes to thereby change the oscillation wavelength. Of course, all the Gunn diodes can be driven at the same time.
Generally the Gunn diodes effects oscillation at a frequency f expressed by
f=Vd/L (6)
wherein Vd is the drift velocity of electrons (about 10 7 cm/sec), and L is the electrode spacing of the Gunn. For example, if L is 10 μm, f is 10 GHz. Since the Gunn diodes 25c of the array 25 have different spacings of L1 to L5 between the electrodes 25a and 25b, one of the Gunn diodes, when selected for oscillation, propagates a SAW having a frequency given by Equation (6) with use of the spacing concerned. When the period of the SAW is Λ, the laser oscillation wavelength λ is expressed by Equation (1). Thus the laser oscillation occurs at one of the wavelengths λ1 to λ5 corresponding to the electrode spacing of the Gunn diode driven.
FIG. 11 shows still another embodiment. The DH structure laser includes an active layer 3, and a film 29 of a material producing an electro-optical effect, e.g. BaTiO 3 , is formed on an exposed portion of the layer 3. A periodic grating 27 is formed on the film 29, for example, by the combination of electron beam exposure or holographic exposure and ion beam etching technique. Opposed electrodes 28 are provided on the BaTiO 3 film 29 on the opposite sides of the grating 27.
When d.c. voltage or a.c. voltage is applied across the electrodes by a power source 30, the resulting electro-optical effect varies the refractive index n of the film 29 provided with the grating 27 to vary the oscillation wavelength. Assuming that the voltage is E, the distance between the electrodes 28 is d, and the electro-optical constant of the film 29 is γ, the variation Δn of the refractive index is expressed by
Δ∝γn.sup.3 E/d (7)
Accordingly the variation Δλ of the laser oscillation wavelength is given by Equation (1) as follows.
Δλ=2ΔnΛ/m∝2γn.sup.3 EΛ/dm (8)
Thus if the voltage E is varied, the laser oscillation wavelength can be varied by Δλ. Since BaTiO 3 has a great electro-optical constant (γ 42 =8.2×10 -10 m/V), use of this material produces great variations in the refractive index to enlarge the bandwidth of tunable wavelengths.
While the embodiments of FIGS. 3 to 11 are DH structure lasers embodying the invention, the invention is of course applicable to semiconductor lasers of other types.
The tunable semiconductor laser of the invention is advantageously usable for wavelength multiplex communication. With reference to FIG. 12, laser beam signals having different wavelengths are delivered from a tunable semiconductor laser 32 of the invention to a light wave branching unit 34 via an optical fiber 33 in response to control signals from a central processing unit 31. The branching unit 34 is connected to optical fibers 35 for channels 1, 2, . . . i. The laser beam signals of varying wavelengths are delivered to the optical fibers 35 by real-time transmission upon switching. The tunable semiconductor laser of the invention, even if used singly, gives laser beam signals of different wavelengths in response to control signals and therefore affords a wavelength multiplex communication system of simple construction.
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A tunable semiconductor laser has an active layer, an insulating film made of a piezoelectric material and formed on a portion of the active layer, and an interdigital transducer provided on the insulating film for generating a surface acoustic wave. The laser oscillation wavelength is variable by varying the wavelength of the surface acoustic wave generated by the transducer. When adapted to produce surface acoustic waves of different frequencies at different locations, the transducer affords an enlarged tunable wavelength band. A plurality of Gunn diodes effecting oscillation at different frequencies are usable in place of the transducer.
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