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RELATED APPLICATIONS
This is a continuation-in-part application of Ser. No. 08/846,982 filed May 1, 2001, now U.S. Pat. No. 6,446,682, issued Sep. 10, 2002, which was a continuation of Ser. No. 09/301,851 filed Apr. 29, 1999, now U.S. Pat. No. 6,223,790, each patent being incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to fluid exchange devices for replacing used fluid with a fresh fluid in a fluid circuit, and more particularly to an apparatus and method of use for achieving a fluid exchange of a fluid circulation circuit such as a vehicular automatic transmission, a vehicular power steering system, a vehicular engine oil system, or a vehicular cooling system.
2. Related Background Art
Various devices have been utilized to achieve fluid exchanges for vehicular automatic transmissions. Applicant's U.S. Pat. Nos. 6,378,657; 6,330,934; 6,267,160; 6,223,79; 6,164,346; 6,105,635; 6,082,416; RE36,65; 5,964,278; and 5,318,080 disclose devices, systems, or methods for performing a fluid exchange. Each of these patents are incorporated by reference herein in their entireties. The prior art also includes various externally powered exchange devices wherein the power to effect an exchange procedure is at least in part provided by an electric pump. Some of these externally powered devices utilize a vehicle's electric system for activation. One unresolved problem has been the need for a fluid exchange system which requires no external power source such as an electric motor or compressed air.
A need also exists for a device for servicing vehicular automatic transmissions having the following characteristics: one which requires no external powering source other than the fluid pressure from the accessed fluid circulation circuit; a reciprocating pump having a pump volume which is a fraction of the fluid volume necessary for the fluid exchange; an onboard fresh fluid supply tank reservoir of a capacity sufficient to perform a fluid exchange for most vehicle automatic transmissions; and a pump matching rates of flow and volumes exchanged during the and exchange procedure.
U.S. Pat. No. 6,223,790 discloses a system able to operate without electrical or compressed air power in its 1st and 5th embodiments, both embodiments being reciprocating fluid exchangers, and both of which employ a mechanically actuated spring and detent operated fluid control valve.
The need remains for such a self powered, fluid flow rate and volume equalized, fluid exchange system where any necessary fluid control valving is provided by an alternative mechanism which does not employ spring and detent, such as disclosed in the first and fifth embodiments of U.S. Pat. No. 6,223,790.
A fluid exchange unit for automatic transmissions, power steering and cooling systems which does not require connection to a vehicle's electric system would be desired. In addition, such a unit can be very portable and useful away from a service station given that no external power supply is required to operate the exchange device This portability is viewed as advantageous and desired by service technicians.
SUMMARY OF THE INVENTION
The present invention solves problems existent in prior hydraulic fluid exchange systems. The present invention provides a compact fluid exchange system having a pump volume which is substantially smaller than the total volume of fluid replaced during the exchange process. The apparatus can be used to service hydraulic fluid systems having a variety of circuit sizes, configurations, etc.
Briefly, the invention includes a cyclical pump having a pair of used fluid chambers and a pair of fresh fluid chambers. The pump receives used fluid from an accessed hydraulic fluid circuit into a used fluid chamber, introduces fresh fluid from fresh fluid chamber into the hydraulic fluid circuit, simultaneously refills the other fresh fluid chamber with fresh fluid, and simultaneously discharges spent fluid from the other used fluid chamber into a spent fluid receptacle. Fluid flow relative to the pump assembly is directed by control valves. The pump cycles until the predetermined exchange volume is satisfied (determined by such means as visual or optical comparison of fluid input and output, sensor devices, etc.). The invention permits connection to both a bulk fresh fluid supply and a floor drain, such as those typically found in vehicle repair facilities.
One object of the invention includes a reciprocating pump assembly having a power medium of a pressurized hydraulic fluid, such as used transmission fluid of an operating motor vehicle during a maintenance procedure, or pressurized fresh fluid from an external source.
One object of the invention provides a fluid exchange apparatus released from the requirement of having dedicated on-board fluid reservoirs. A remote bulk fresh fluid supply and remote waste fluid receptacle, such as those found in vehicle repair facilities, may be utilized to practice the present invention. In this manner, a smaller, more compact fluid exchange apparatus is provided.
One object of the present invention is a device which permits an efficient change between different fresh fluids (grades, additive packages, etc.) between or during exchange procedures. The limited volumetric capacity of the pump assembly and associated conduit results in a limited amount of the previous different fresh fluid charge held within the exchange apparatus.
One object of the invention is to provide a fluid exchanger which is self-powered by pressure in the accessed fluid circulation circuit thereby removing the need to connect the exchanger to the electrical system of a vehicle being serviced or to an external electrical outlet or compressed air supply. This allows a high degree of portability and minimizes the potential of electronic component damage.
Another object of the invention is to provide a fluid exchanger which is especially suitable to replace the contents of fluid systems in addition to automatic transmissions in vehicles. There is the need for a fluid exchanger which can be adapted and manufactured to replace the contents of fluid circuits such as those of vehicular cooling systems, engine oil systems, and power steering system, and as well the high flow, high pressure hydraulic circuits of heavy construction and other commercial and industrial equipment such as cranes, fork-lifts, front-loaders, plows, road graders, garbage trucks, hydraulically operated industrial and farm implement machinery, and aircraft hydraulic circuits, as well as many other fluid circulation circuits in everyday use or which will be later developed which can or will benefit from complete or near complete fluid exchanging.
One object of the invention is to provide a fluid control mechanism for a reciprocating fluid exchanger which may be powered by the accessed fluid circulation circuit, including low flow foreign vehicle automatic transmissions.
Another object of the invention is to also provide a fluid control mechanism which is reliably activated and more durable for exchanging the fluid of high fluid flow, high fluid pressure fluid circulation circuits such as large, commercial trucks or other industrial or commercial equipment or machines used in manufacturing.
The present invention provides a fluid exchange system in a preferred embodiment which employs a mechanically actuated pilot valve which in turn fluidly operates a used fluid control valve. A fluid exchange machine of the present invention can be utilize in exchange procedures for low to high fluid pressure systems. High pressure systems may include farm tractors, heavy construction machinery, and industrial machines used in manufacturing.
Another object of the invention is to provide a self-loading fluid exchanger which exchanges approximately equivalent volumes of fresh fluid for used fluid at approximately the same rates of flow, and a fluid exchanger with a pump capacity much smaller than the fluid capacity of its fresh fluid reservoir.
One object of this invention is to provide a simple mechanical automatic bypass valving system which requires no source of electrical power.
Another related object of the invention is a means to manually shift the exchanger into bypass mode.
Another object of the invention is to provide a fluid exchanger which can be utilized to exchange the fluid in other fluid circulation circuits, such as circuits containing motor or engine oil, hydraulic fluid, antifreeze or other coolant, water, chemicals, or products circulated in fluid circuits used in passenger vehicles, and commercial or industrial vehicles or equipment, or machines used in industry including food processing and chemical processing.
DESCRIPTION OF THE DRAWINGS
The present invention will be described hereafter in the Detailed Description of Preferred Embodiments, taken in conjunction with the following drawings, in which the reference numerals refer to like elements throughout.
FIG. 1 is a perspective, partially diagrammatic, illustration of one embodiment of the present invention.
FIG. 2 is a cross sectional view of a portion of the embodiment of FIG. 1 .
FIG. 3 is a cross sectional view of a portion of the embodiment of FIG. 1 .
FIG. 4 is a cross sectional view of a portion of the embodiment of FIG. 1 .
FIGS. 5 through 8 are diagrammatic illustrations of operation of the embodiment of FIGS. 1-4 .
FIG. 9 is a diagrammatic cross sectional view of a control valve for use in an alternative embodiment of the present invention.
FIG. 10 is a diagrammatic cross sectional view of a bypass valve assembly for use in another embodiment of the present invention.
FIG. 11 is a perspective view of a portion of the bypass valve of FIG. 10 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
As shown in FIG. 1 , one embodiment of the invention includes a pump 425 including two reciprocating pistons 453 , 455 linked by a connecting rod 452 within a cylinder block 339 as further depicted in FIG. 2 . Pump 425 includes a first and second used fluid pumping chambers 20 , 30 and a first and second fresh fluid pumping chambers 10 , 40 . The pumping chambers 10 , 20 , 30 , 40 are variable volume chambers with the volume of each being defined by the relative position of the pistons 453 , 455 within cylinders 399 , 401 . As described in more detail hereinafter, in the embodiment of FIGS. 1 through 8 , the driving force for pump 425 is supplied by pressurized used fluid received from an accessed hydraulic circuit wherein the pressurized used fluid is directed, in alternating manner, to either pumping chamber 20 or pumping chamber 30 . Pump 425 has a used fluid control valve assembly 423 in communication with cylinder block 339 and used fluid received from the vehicle or other device being serviced. In an alternative embodiment, such as a device incorporating the valve of FIG. 9 , the driving force for pump 425 may be supplied by pressurized used fluid (as provided by the accessed hydraulic circuit) and pressurized fresh fluid (as provided by an external fluid pump).
Pump 425 has a left cylinder 399 which is secured in position between a left cylinder head 427 and cylinder block 339 by four headbolts, two of which are shown, a headbolt 431 and a headbolt 433 . Pump 425 has a right cylinder 401 which is secured in position between a right cylinder head 429 and cylinder block 339 by four headbolts, two of which are shown, a headbolt 435 and a headbolt 437 . A conduit tee 405 is suitably connected to a port 445 of cylinder head 427 . Conduit tee 405 includes a pair of checkvalves 407 , 409 . A conduit tee 406 is suitable connected to a port 447 of cylinder head 429 . Conduit tee 406 includes a pair of checkvalves 411 , 413 .
A fresh fluid supply conduit 415 is attached to a fresh fluid tank assembly 417 at one end and to checkvalve 407 and checkvalve 411 at its other two ends. Tank 417 has a fill cap 421 which is vented and contains a fresh fluid supply 419 . A fresh fluid conduit 403 is attached at one end to a quick connector 335 and attached to checkvalve 409 and 413 at its other two ends. A waste fluid conduit 317 is arranged at one end to discharge a used fluid 430 into a used fluid receiver 381 and connected to a waste port 307 of cylinder block 339 and to a waste port 309 of cylinder block 339 at its other two ends. A waste conduit assembly 311 is arranged at one end to discharge used fluid 430 into used fluid receiver 381 and is connected to a waste port 353 of valve 423 and to a waste port 355 of valve 423 at its other two ends. A sightglass 318 is provided to conduit assembly 311 . Sightglass 318 permits the operator to view the clarity of fluid within conduit 311 , for example so as to determine completion of an exchange procedure.
A used fluid supply conduit 369 is connected at one end to a quick connector 333 and connected to a port 347 of valve 423 and a port 301 of cylinder block 339 at its other two ends. Connector 333 is adapted to be coupled into the accessed fluid circuit, such as a vehicles automatic transmission cooling circuit so as to receive used fluid therefrom.
A conduit 313 connects a port 357 of valve 423 to a port 303 of cylinder block 339 . A conduit 315 connects a port 359 of valve 423 to a port 305 of cylinder block 339 .
FIG. 2 more fully illustrates pump assembly 425 . Pistons 453 , 455 each include threaded structures 448 , 454 , respectively, for coupling pistons 453 , 455 to connecting rod 452 . Pump 425 has a cylinder block 399 which is secured between cylinder head 427 and cylinder block 339 by four headbolts, two of which are shown in FIG. 1 . Pump 425 has a cylinder 401 which is secured between cylinder head 429 and cylinder block 339 by four headbolts, two of which are shown in FIG. 1 . In this particular embodiment, piston 453 and piston 455 are cylindrical in form, as is connecting rod 452 , and cylinder 399 and cylinder 401 . Other shapes and configurations of pistons, connecting rods, and cylinders can be utilized without departing from the art depicted herein in this embodiment.
Cylinder head 427 is provided with port 445 . Cylinder head 429 is provided with port 447 . Cylinder block 339 is provided with two ports, a port 377 which connects to first used fluid powering chamber 20 , and a port 379 which connects to second used fluid powering chamber 30 .
Cylinder block 339 has a bore 321 into which connecting rod 452 is slidingly received and suitably fitted to provide smooth sliding operation and limited leakage. Cylinder block 339 has two circumferencial glands 329 , 331 which serve to hold two gaskets of suitable material, one per side (not shown), which gaskets are disposed between cylinder 399 and cylinder block 339 , and between cylinder 401 and cylinder block 339 . Cylinder head 427 has a circumferencial gland 332 which serves to hold a gasket of suitable material (not shown) between cylinder 399 and cylinder head 427 . Cylinder head 429 has a circumferencial gland 329 which serves to hold a gasket of suitable material (not shown) between cylinder 401 and cylinder head 429 . If desired, and/or in high pressure embodiment of the present invention, seals can be provided to rod 452 , and pistons 453 and 455 .
FIG. 3 depicts a cross sectional view of cylinder head 339 with a pilot valve spool 323 slidingly received into a pilot valve bore 337 . As described with reference to FIGS. 5-8 , spool 323 is repeatedly engaged and moved by pistons 453 , 455 during an exchange procedure as pistons 453 , 455 travel toward block 339 . Bore 337 includes recessed areas 327 , 328 at respective ends. Valve spool 323 has a right endstop 330 suitably secured to its right end and a left endstop 325 suitably secured to its left end. Endstops 325 and 330 are slidingly insertable into corresponding recessed areas 327 , 328 . Various means can be utilized to secure endstops 325 and 330 on end each of valve spool 323 , such as matingly providing male threads to each end of valve spool 323 and female threads to each endstop 325 and 330 . As with securing pistons 453 and 455 to connecting rod 452 , a suitable thread locking compound can be applied to the threads in order to securely fix endstops 325 and 330 to valve spool 323 . Recessed area 328 is sized to slidingly receive endstop 330 , as is recessed area 327 sized to receive endstop 325 . Valve spool 323 is configured to provide fluid communication between two pair of its ports 301 , 303 , 305 , 307 , 309 at a time.
As with cylinders 399 , 401 and pistons 453 , 455 , alternate shapes for the pilot valve bore 337 and pilot valve spool 323 other than cylindrical can be used without departing from the art depicted herein, as long as the fit between each is suitably snug to prevent unacceptable levels of leakage. Pilot valve bore 337 has five ports 301 , 303 , 305 , 307 , 309 . Port 301 is coupled to conduit 369 . Port 303 is coupled to conduit 315 . Port 305 is coupled to conduit 313 . Waste port 307 and waste port 309 are coupled to waste conduit 317 . No detent or position locking mechanism is required to hold spool 323 in place after it has been moved into each one of its two alternate, shifted positions which occur as a result of the movement of pistons 453 , 455 .
FIG. 4 depicts more clearly the used fluid control valve 423 . Valve 423 has a valve body 361 . Valve body 361 has a valve bore 360 into which a valve spool 367 is slidingly received. Valve bore 360 is provided with seven ports 347 , 349 , 351 , 353 , 355 , 357 , 359 . Valve 423 includes a threaded end plug 363 and a threaded endplug 365 . Port 357 is connected to conduit 313 and port 359 is connected to conduit 315 . Valve body 361 is provided with an O-ring gland 362 at one end and an O-ring gland 364 at the other end. Port 349 is in fluid communication with port 377 of cylinder block 339 . Port 351 is in fluid communication with port 379 of cylinder block 339 . In another embodiment, valve assembly 423 may be is secured directly to cylinder block 339 (not shown). This direct mounting of valve 423 to cylinder block 339 directly connects ports 349 and 351 of valve 423 to ports 377 and 379 of cylinder block 339 , respectively. Port 347 is connected to conduit 369 , and ports 353 and 355 are connected to waste conduit 311 . Valve spool 367 is configured to provide fluid communication between two ports at a time depending on its particular position within valve body 361 . The particular position of valve spool 367 in the valve bore 360 determines which adjacent ports communicate with each other.
Operation of the Embodiment of FIGS. 1 - 4
FIGS. 5 through 8 illustrate operation of the embodiment of the present invention of FIGS. 1 through 4 . FIGS. 5 through 8 are partially diagrammatic in that arrows represent fluid flow within the exchange device during an exchange procedure.
The closed fluid circulation circuit of an automatic transmission, or other hydraulic fluid circulation circuit is accessed and opened to provide a higher pressure side and lower pressure or return side. Adapters with matingly compatible connections (not shown but understood by those with ordinary skill in the art) are connected at one end of each to one side each of the opened fluid circulation circuit, which in this case is the cooling circuit of an automatic transmission. The remaining end of each adapter is matingly connected to a selection of one of the pair of quick connectors 333 and 335 of FIG. 1 , with the adapter connected to the pressure side of the circuit connected to quick connector 333 and the adapter connected to the low pressure or return side of the circuit connected to quick connector 335 . The use of specific adapters or connectors is not an necessary element of the present invention. A variety of connection approaches may be made to inteconnect the exchange device of the present invention with a hydraulic circuit, such as an automatic transmission of a vehicle.
FIGS. 5 through 8 illustrate that valve spool 367 is movable within valve bore 360 in response to fluid pressures communicated through conduits 313 , 315 . The position of valve spool 367 in valve bore 360 of used fluid control valve 423 is determined by the position of valve spool 323 in pilot valve bore 337 which itself is determined by whether piston 453 or piston 455 last made contact valve spool 323 . The direction of movement and the actual point of reversal of direction of movement of piston/rod/piston assembly 453 / 452 / 455 as illustrated in FIGS. 5 through 8 is determined by which of the two positions valve spool 367 of valve 423 is in. There is a causal interdependency between valve spool 323 , valve spool 367 , and the direction of movement of piston/rod/piston assembly 453 / 452 / 455 which results in a circular chain of events. This chain of events starts with the fluid pressure of the accessed fluid circulation circuit maintaining both valve spools 323 and 367 in position while simultaneously moving piston/rod/piston assembly 453 / 452 / 455 in the direction as determined by valve spools 323 and 367 .
When the fluid circulation circuit being serviced is pressurized, in this case when the engine is started and operated to render the automatic transmission operative to pump fluid through its cooling circuit, used fluid flows from the cooling circuit through quick connector 333 , into conduit assembly 369 to thereby supply pressurized used fluid to port 347 of control valve assembly 423 and port 301 of cylinder block 339 . Used pressurized fluid from the accessed hydraulic circuit provides the power necessary to effect a fluid exchange using embodiments of the present invention.
The particular path of the pressurized used fluid after flowing through port 347 is dependent on the position that valve spool 367 is in within valve bore 360 . In any event, pressurized used fluid is directed in alternating manner to one of the used fluid pumping chambers 20 , 30 . In operation, the pistons 453 , 455 move in a repeated cyclical manner. Check valves 407 , 409 , 411 , 413 control the flow of fluid within conduits 403 , 415 .
FIG. 5 illustrates used pressurized fluid being received into valve 423 through ports 347 , 349 and into port 377 of block 339 where it enters used pumping chamber 20 . Pressurized used fluid within chamber 20 forces piston 453 away from block 339 to have the following effects: (1) fresh fluid within chamber 10 is forced into conduit 403 for introduction into the accessed circuit, (2) used fluid within chamber 30 is directed through ports 351 , 355 of valve 423 and into conduit 311 for disposal in receiver 381 , and (3) fresh fluid is drawn into chamber 40 through conduit 415 from fresh fluid supply 417 . Piston 453 continues to move away from block 339 until the condition of FIG. 6 is reached.
FIGS. 6 and 7 illustrate movement of valve spools 367 , 323 relative to that of FIG. 5 . FIGS. 6 and 7 illustrate used pressurized fluid being received into valve 423 through ports 347 , 351 and into port 379 of block 339 where it enters used pumping chamber 30 . Pressurized used fluid within chamber 30 forces piston 455 away from block 339 to have the following effects: (1) fresh fluid within chamber 40 is forced into conduit 403 for introduction into the accessed circuit, (2) used fluid within chamber 20 is directed through ports 349 , 353 of valve 423 and into conduit 311 for disposal in receiver 381 , and (3) fresh fluid is drawn into chamber 10 through conduit 415 from fresh fluid supply 417 . Piston 453 continues to move away from block 339 until the condition of FIG. 7 is reached, i.e. piston 453 is in contact with valve spool 323 . As piston 453 move closer to block 339 , valve spool 323 is biased into its other position as indicated in FIG. 5 .
FIG. 8 illustrates movement of valve spool 323 into its other position thereby effecting a change in the position of valve spool 367 . Upon valve spool 367 assuming the position as indicated in FIG. 8 , used pressurized fluid being received into valve 423 through ports 347 , 349 and into port 377 of block 339 where it enters used pumping chamber 20 . Pressurized used fluid within chamber 20 forces piston 455 away from block 339 to have the following effects: (1) fresh fluid within chamber 10 is forced into conduit 403 for introduction into the accessed circuit, (2) used fluid within chamber 30 is directed through ports 351 , 355 of valve 423 and into conduit 311 for disposal in receiver 381 , and (3) fresh fluid is drawn into chamber 40 through conduit 415 from fresh fluid supply 417 . Piston 453 continues to move away from block 339 until the piston 455 contacts valve 323 . As piston 455 move closer to block 339 , valve spool 323 is biased into its other position as indicated in FIGS. 6 and 7 . The cyclical interaction between pistons 453 , 455 and valves 323 and 367 , as illustrated in FIGS. 5 through 8 , continues during the exchange procedure whereby quantities of used fluid and fresh fluid are exchanged. As pumping chambers 10 , 20 , 30 , 40 have equivalent size, the flow rates between used and fresh fluid are substantially equivalent. The exchange procedure may be terminated by an operator, such as after viewing the used fluid in sightglass 318 to determine completion of the exchange.
FIG. 9 illustrates a combination fresh and used fluid control valve assembly 494 . This valve can be substituted for the used fluid control valve 423 , conduit tees 405 , 406 and checkvalves 407 , 409 , 411 , and 413 of the embodiment of FIGS. 1 through 8 . This substitution is desirable when a pressurized fresh fluid supply is substituted for open, vented tank 417 . Such a pressurized fresh fluid supply (not shown but understood by someone of ordinary skill in the art) can be comprised of the addition of an onboard air powered or electrically powered pump connected in series or parallel (with a bypass around such a pump and a downstream flowing checkvalve) to deliver and/or to augment the flow of fresh fluid 419 from fresh fluid tank 417 . This is indicated when fresh fluid 419 cannot be adequately drawn into pump 425 . An air powered pump (not shown) can be powered by a stored and regulated onboard supply of compressed air held in a suitable pressure vessel. An electric powered pump can be powered by an onboard rechargeable battery or a removable and replaceable battery pack.
Valve 494 has a valve body 471 and is provided with a valve bore 472 receiving a valve spool 473 . Valve body 471 has thirteen ports 451 , 456 , 449 , 455 , 457 , 459 , 461 , 463 , 465 , 467 , 469 , 477 , 481 , of which ports 477 and 481 are integral one each with a threaded end plug 475 , 483 . Both threaded end plugs 475 and 483 are provided with O-ring glands 485 and 479 respectively, to which O-rings which are suitably resistant to fluid 419 of tank 417 and fluid of used fluid receiver 381 . Port 456 is coupled to conduit 352 in fluid communication with port 379 . Port 451 is coupled to a conduit 350 in fluid communication with port 377 . Port 463 is coupled to a conduit 491 which is connected to port 445 . Port 467 is coupled to a conduit 493 which is connected to port 447 . Port 481 is coupled to a conduit 313 which is connected to port 305 . Port 477 is coupled to a conduit 315 which is connected to port 303 . Ports 459 and 469 are coupled to conduit 403 which is coupled to quick connector 335 of FIG. 1 . Ports 461 and 465 are coupled to conduit 415 which is connected to tank 417 of FIG. 1 . Ports 455 and 457 are coupled to conduit 311 which directs fluid into fluid receiver 381 of FIG. 1 . Port 449 is coupled to conduit 369 which is connected to quick connector 333 of FIG. 1 .
The combination fresh & used fluid control valve assembly 494 of FIG. 9 when installed on the first preferred embodiment depicted in FIGS. 1-8 , provides an additional preferred feature of allowing the use of a pressurized fresh fluid source feeding conduit assembly 415 .
In operation, when conduit 313 is provided pressurized fluid from pilot valve spool 323 through conduit 313 while conduit 315 is vented by pilot valve spool 323 through conduit 315 , valve slide 473 of valve assembly 494 is moved to the right side of valve bore 472 and is held in place against threaded end plug 475 . This results in the fluid connection of ports 461 and 463 , 451 and 449 , 456 and 457 , and 467 and 469 , which in turn results in the fluid connection of conduits 491 and 415 , 350 and 369 , 352 and 311 , and 493 and 403 .
This right position (as indicated in FIG. 9 ) of valve spool 473 in valve bore 472 results in the following events: used fluid from conduit 369 is provided to the left used fluid powering chamber 20 which moves piston/connecting rod/piston assembly 453 / 452 / 455 to the left, thereby providing fresh fluid from the left fresh fluid chamber 10 to conduit 403 , and fresh fluid is simultaneously provided to right fresh fluid chamber 40 from tank assembly 417 through conduit 415 , while also simultaneously forcing used fluid from right used fluid powering chamber 30 to be discharged into conduit assembly 311 for delivery into used fluid receiver 381 .
As piston/connecting rod/piston assembly 453 / 452 / 455 reaches its end of stroke against cylinder head 339 , the pilot valve spool 323 is moved into its right position, bring left endstop 330 fully into cavity 328 . This results in pressurized used fluid being provided to conduit 315 and port 477 and pilot valve spool 323 venting the captive fluid through port 481 to conduit 313 . This results in valve spool 473 being moved to its left position against threaded end plug 483 . This shifting of pilot valve spool 473 from its right position to its left position, reverses the movement of piston/connecting rod/piston assembly 453 / 452 / 455 , which then results in the following fluid connections being made by valve assembly 494 , fluid connection is established between ports 463 and 459 , 451 and 455 , 456 and 449 , and 467 and 465 , which in turn results in the fluid connection of conduits 491 and 403 , 350 and 311 , 352 and 369 , and 493 and 415 .
This second position of valve spool 473 in valve bore 472 results in the following events:
used fluid from conduit 369 is provided to the right used fluid powering chamber 30 which moves piston/connecting rod/piston assembly 453 / 452 / 455 to the right, thereby providing fresh fluid from the right fresh fluid chamber 40 to conduit 403 , and fresh fluid 419 is simultaneously provided to left fresh fluid chamber 10 from tank assembly 417 through conduit 415 , while used fluid is also discharged from left used fluid powering chamber 20 into conduit assembly 311 for delivery into used fluid receiver 381 .
Use of valve 494 allows the provision of a delivery pump to conduit assembly 415 . It also allows the application of a flow-augmenting boost pump to conduit assembly 415 . Each of these options establishes the use of the pumping chambers 10 , 40 as combination pumping and powering chambers in addition to chambers 20 , 30 . These options allow the removal of any portion of or all of the total resistance applied to the fluid circulation circuit being serviced with a fluid exchange, thereby allowing the removal of a portion or all of the work being done by the fluid pressure provided by the fluid circulation circuit for the fluid exchange. This is especially useful to increase the speed in which the fluid of low pressure, low flow fluid circulation circuits may be replaced. If the total fluid resistance of a fluid exchange system is significant, flow in the accessed circuit may be reduced to such an extent that damage to the system can occur. Utilization of the present invention may reduce the fluid resistance of a fluid exchange machine so that embodiment of the present invention may be used in a variety of different fluid circuits.
FIGS. 10 and 11 illustrate a float operated automatic bypass valve for use in alternative embodiments of the present invention. FIGS. 10 and 11 do not show the reciprocating parts of the fluid exchanger since a number of embodiments are interchangeably usable. The necessary fluid lines for connecting to the reciprocating part of the fluid exchanger are however shown.
A floater operated bypass valve assembly 200 is comprised of a valve body 203 with a valve slide 201 . Valve body 203 is provided with an incoming port 211 for spent fluid from transmission and an outgoing port 213 for fresh fluid delivery. Valve 203 also has an inlet port 219 for fresh fluid provided by the pump and an outlet port 221 for spent fluid from the accessed circuit. Valve slide 201 has an internal fluid passage 209 which, when in proper position with valve slide 201 in its downward position, connects incoming port 211 to outgoing port 213 . Valve slide 201 has a plug 215 which is secured and sealed into the machining access port end of passage 209 , allowing the easy machining of passage 209 without custom casting if so desired. Valve body 203 and valve slide 201 may be constructed of steel, aluminum or other suitable or desired alloys, or can be constructed of a number of suitable plastics including the highly durable acrylics and carbon fiber compounds as well as suitable nylon type compounds or other special plastic compounds fluorinated for durability and prevention of fluid absorption. Valve slide 201 is provided with a vertical vent passage 217 and an anti-rotation vertical alignment slot 222 . Valve body 203 has a threaded port 224 to receive a male threaded pin 220 for anti-rotation slot 222 .
Valve slide 201 has a circumferential fluid passage for fresh fluid provided by exchanger 223 and a circumferential fluid passage for spent fluid provided to exchanger 225 . A fresh fluid reservoir tank 227 is provided and is connected to valve body 203 and a reinforcing plate 255 by a set of screws 257 and 259 (the additional two screws are not shown). Tank 227 is provided with a float which is connected to valve slide 201 by a male threaded at both ends shaft 231 , which is screwed into a female threaded receiver 232 of valve slide 201 at one end and which is screwed into float 229 at a female threaded receiver 233 . A fluid vent port 234 and a fluid vent port 236 are provided to tank 227 and support plate 255 . Tank 227 has a fresh fluid outlet port 235 which is connected to a fresh fluid inlet supply tube 244 which is in turn also connected to a two position lever operated on/off ball valve 241 which is in turn connected to a drain outlet tube 239 . Float 229 has a female threaded receiver 238 into which a threaded bearing 237 is screwed. Port 219 is connected to a fresh fluid outlet supply tube 245 . Port 221 is connected to spent fluid inlet tube 243 . A fresh fluid outlet hose 247 connects port 213 to a female quick connect 251 . A spent fluid inlet hose 249 connects port 211 to a female quick connect 253 . Quick connect 251 is connected to an adapter which is in turn connected to the outlet side of an opened cooling circuit of an automatic transmission (not shown). Quick connect 253 is connected to an adapter which is in turn connected to the return side of an opened cooling circuit of an automatic transmission (not shown). Valve body 203 is provided with 4 female threaded receivers, of which two are shown, female threaded receivers 256 and 258 which receive screw 257 and screw 259 .
Tank 227 is provided with a cross bar support bracket 263 which has a plunger guide 267 and set of weight saving bracket holes 265 . Plunger guide 267 holds a plunger 273 which has a retainer end 276 on its bottom end and a plunger return spring 271 and a washer 278 on its top end. Plunger 273 is provided with a pivot pin 275 . Bracket 263 has a horizontal lever 277 which has two holes, one placed to hold to pivot pin 275 and the other a slide slot 284 which is rotatable on a slide pin 283 which is affixed to the top of plunger 273 . Horizontal lever 277 is fitted at approximate mid point with a pivot pin 281 which receives a vertical lever 279 . Vertical lever 279 is connected to a manually operated detent assembly (not shown). Note, that pivot pins 275 and 281 and slide pin 283 are provided with suitable fasteners such as end-mounted retainer clip caps (not shown).
Tank 227 and all of its integral parts, including float 229 may be made of steel, aluminum, suitable alloys, or suitable plastics or fiberglass compounds. Float 229 should be highly buoyant and filled with air or other suitable gas or lighter than oil foam plastic, each of which should be either shielded from oil by sealing technology (for example fluorination) or comprised of oil insensitive materials.
When fresh fluid reservoir tank 227 is empty, float 229 is in its lowermost position and causes valve body 201 via shaft 231 to also be in its lowermost position under power provided by the weight of float 229 , bearing 237 and shaft 231 . Float 229 is constructed of material light enough and large enough to be sufficiently buoyant in automatic transmission fluid to overcome its own weight of shaft 231 , the weight of valve slide 201 , and any resistance to movement of shaft 231 and valve slide 201 , all cumulative, such that valve slide 201 will rise to its uppermost position when tank 227 has a sufficient volume of fluid to allow the reciprocating exchanger to operate. On the other hand, the sum total weights of float 229 , bearing 237 , shaft 231 and valve body 201 must be great enough to overcome any resistance to movement that exists when the fluid level in tank 227 has dropped below a level providing any buoyancy to float 229 .
Fresh automatic transmission fluid is added into the fresh fluid reservoir tank 227 to a level well above the float and it is contained herein until consumed and discharged by the reciprocating fluid exchanger disclosed in this specification which can be connected to tubes 243 , 244 and 245 . This fresh fluid then displaces float 229 thereby raising float 229 to its uppermost position which simultaneously raises shaft 231 which pulls valve slide 201 to its uppermost position. Note: if the operator has inadvertently filled tank 227 with the wrong type of fluid desired, he or she can drain that fluid out at drain outlet tube 239 by opening ball valve 241 until that fluid is all out.
Vertical lever 279 is held by a detent mechanism in its upward position (detent mechanism not shown) and is not holding float 229 in its downward position. Of course, the operator can choose to move this lever 279 to a lower detented position at anytime which will move lever 277 downward to overcome plunger return spring 271 and any buoyancy provided by any fluid in tank 227 , thereby causing plunger 273 to move its downward position to make contact with bearing 237 to thereby simultaneously force float 229 and valve slide 201 to their downward positions. Vertical lever 273 can be so moved if the operator desires to use lever 279 as a manual override for the automatic bypass valve function provided by fluid buoyancy to float 229 and can also be manually raised at any time from its lower detented position to its upper detented position.
When vertical lever 279 causes valve slide 201 to move its downward position this causes the valve slide to assume its downward position which establishes a bypass fluid connection between hoses 249 and 247 through ports 211 and 213 through the internal fluid passage 209 of valve slide 201 . Correspondingly when the fluid level in tank 227 is depleted to the point of denying sufficient buoyancy to float 229 , valve slide 201 also is caused to move its downward position under the sum total weight of float 229 , bearing 237 , shaft 232 and the valve slide 201 itself, thereby also establishing a bypass connection between hoses 247 and 249 .
When a bypass connection is established between hoses 247 and 249 , the transmission can freely circulate its fluid through the exchange device and its cooling circuit without any fluid exchanging occurring or without any significant loss of volume of fluid. This can allow the operator time to evaluate the flow rate and clarity of the fluid, as well as determine the current level of fluid in the transmissions pan as verified by checking the dipstick indication.
When vertical lever 279 is in its upward detent position and there is a sufficient level of fluid in tank 227 , the buoyancy provided to float 229 by the fluid raises valve slide 201 to its upward position when thereby causes port 211 to communicate with port 221 through the circumferential fluid passage 225 while simultaneously causing port 213 to communicate with port 219 through circumferential fluid passage 223 , while also simultaneously causing fluid passage 209 to be blocked by valve body 203 . When valve slide 201 is caused to be in its upward position by buoyancy provided to float 229 by a sufficient volume of fluid contained in tank 227 , the communication of port 211 and 221 and the simultaneous communication of port 213 to 219 occurs and this causes the reciprocating fluid exchanger to operate if the transmission is operative to pump fluid into its cooling circuit to circulate therein.
This operation of the reciprocating fluid exchanger then is accompanied by the flow of fresh fluid from tank 227 to the fresh fluid inlet of the reciprocating exchanger (not shown) through tube 244 , the flow of spent fluid from the transmission cooling circuit into and through connector 253 through hose 249 , through port 211 , through circumferential fluid passage 225 , through port 221 and into and through tube 243 to the reciprocating exchanger, and this is also simultaneously accompanied by the outflow of fresh ATF from the reciprocating exchanger to the transmission cooling circuit into and through tube 245 , via passage through port 219 , through circumferential fluid passage 223 , through port 213 , through hose 247 and through connector 251 .
As long as the fluid level of tank 227 is high enough to provide sufficient buoyancy to float 229 , valve slide 201 stays in its upward position and allows the reciprocating fluid exchanger to operate as long as the transmission is operative to pump spent fluid into its cooling circuit to circulate it therein. As soon as the reciprocating exchanger has consumed enough fresh fluid from tank 227 as provided through port 235 and tube 244 to cause the fluid level to drop in tank 227 to the point of denying sufficient buoyancy to float 229 , float 229 drops to its lower position along with valve slide 201 thereby causing the bypass valve assembly 200 to function in its bypass mode. As long as there is a sufficient volume of fresh fluid in tank 227 to provide enough or sufficient buoyancy to float 229 to cause valve slide 201 to assume and remain in its upper position, bypass valve assembly 200 will function in and remain in its fluid exchange mode.
Known to those of ordinary skill in the art are various methods of connecting conduits together and to valves and to quick connectors or other fittings, and these methods include the use of many types of hose barbs, push-lock and ferrule secured, or other types such as tubing inserted into plastic push-lock receivers. For sake of brevity these are not shown. Also known to those of ordinary skill in the art are various methods of establishing fluid communication between desired fluid system components, such a flexible hose type conduits of appropriate composition for the fluid being exchanged, and use of other types of tubing and conduit material including flexible plastic, bent metals of a variety of compositions, and braided high pressure, reinforced hydraulic hose with machine or hand installed end fittings. For sake of brevity these are not shown. As is known to those of ordinary skill in the art, the actual composition and type of any conduit selected as well as the inside diameter chosen must be based on length of fluid delivery, pressure of the fluid and acceptable resistance levels, and the desired operating characteristic of the conduit arrangements. For example, if a fluid exchange system is designed to exchange the fluid of very low flow fluid circulation circuits, a relatively large inside diameter, and relatively short selection and arrangement of conduits is desirable and indicated. For sake of brevity the extensive type, compositions and pressure and chemical resistance ratings of the various type of conduits, flexible and rigid will not be discussed herein since these considerations are understood by those with ordinary skill in the art.
Many other types and configurations of movable fluid separation members (in these embodiments pistons 453 , 455 ) can be used such as diaphragms linked by a connecting rod, or linked rotors. In addition the number of fluid chambers provided, the number of fluid separation members, the number of connecting rods, and the number of pilot valves and fluid control valves can be quite varied without departing from the art. For example, one could construct a fluid exchange system comprised of two pilot valves, each with isolated functions providing half the needed actuation of a pilot valve or valves if more than one used. Such a system could include two pilot valves with isolated functions providing half the needed control and could incorporate four pistons and three connecting rods between them linking them. Alternatively, one could use three diaphragms with two connecting rods and size theses diaphragms such that the volumes of fluid moved by two during operation of the system to exchange fluid equal the volume moved by the third, thus provided proper approximate equalization between fresh fluid introduction to the fluid circulation circuit and used fluid delivery out of the fluid circulation circuit having its fluid exchanged. Any number of sizes and configurations of fluid separation members with the numeric double number of chambers can be selected with the appropriate corresponding number of connecting rods, and as well. Any number of sizes and configurations of pilot valves and fluid control valve can be selected according to this novel art, as long as the necessary functions required for proper reciprocating operation will be provided for, as will be further explicated. A wide selection of suitable materials can be used to construct the preferred embodiments including special fiberglass resins and exotic plastic compounds, depending on the heat and pressures which must be handled, and materials which include specialized aluminum alloys and aluminum/magnesium alloys, as well as various grades of steel. In this case the preferred embodiments pump assembly, pilot valve and fluid control valve are constructed of aircraft grade aluminum alloy. If diaphragms are used as the fluid separation members, the use of seals, if needed at all, is only an issue where the connecting rod slidingly impacts its bore. One could of course alternatively position the used fluid powering chambers at either ends of the pump, one each, and the fresh fluid pumping chambers at the inside bordering the cylinder block, one to each side of it, and this would result in the piston/rod/piston assembly being pushed rather than being pulled. The same pilot valve configuration could be used without affecting the overall fluid changing function, and this would be true for the use of other types of linked fluid separation members, such as diaphragms or rotors. In the case of using pistons as the fluid separation members, such as in the preferred embodiments herein, piston rings and seals of various types can be fitted. Or alternatively, relatively tight piston to cylinder wall clearances can be used providing sufficient sealing without the cost of such seals. In the preferred embodiments herein piston to cylinder wall clearances are approximately 0.001 inch providing an acceptable seal without significant piston to cylinder wall resistance.
Not shown but understood by those with ordinary skill in the art is the manner in which the embodiment of FIG. 1 is connected to an opened fluid circulation circuit which will have its fluid exchanged. After the fluid circulation circuit is opened at a suitable location, adapters which are matingly compatible are then connected to either side of the opened circuit, one each. These adapters terminate in quick connectors which are matingly compatible with the quick connects 333 , 335 of FIG. 1 . The adapter connected to the pressure side of the circuit must then be connected to quick connect 333 and the adapter connected to the low pressure side must then be connected to quick connect 403 . If a fluid flow alignment mechanism (such as depicted in U.S. Pat. Nos.: Re.36,650; 6,082,418; 6,27,160; or 6,330,934) is incorporated into conduits 369 , 403 , it is not necessary for the operator to identify the higher pressure side of the opened circuit before connecting conduits 369 , 403 to the adapters which have been connected to either side of the opened circuit, one to each. Adapters can be constructed of a wide variety of suitable materials and lengths and this will not be discussed further because it is understood by those with ordinary skill in the art and for the sake of brevity.
Another preferred embodiment (not shown) is one which has no pilot valve, but instead has an equivalent structure comprised of a combination of position sensors mounted in either the cylinder block or cylinder heads of the pump assembly and an electrical solenoid operated hydraulic valve receiving fluid pressure from the fluid pressure of the fluid circulation circuit being serviced, directly or indirectly. There are a number of types of position sensors available which function suitable such as use of magnetically triggered micro-switches, hall-effect sensors as well as other more sophisticated types such as inductive sensors. These sensors can be configured and arranged to alternatingly activate a latching relay configuration which in turn alternatingly energizes and holds energized an electric solenoid until de-energized by a second sensor signal at opposite end of stroke which then de-energizes the solenoid of a two-position four way valve or equivalent. Latching relays can mechanical or solid state. Because latching relays can hold their connection even after the triggering electric current is stopped, they are applicable to this embodiment. In this way pressurized fluid pressure and venting are alternatingly provided to each end of the fluid control valve under control of the latching relay and the triggering signals which activate the relays switching of connections. Thus, this positions sensor based valve actuating mechanism can be arranged and configured for a piston to trigger a positions sensor when it reaches its end of stroke, which in turn triggers a latching relay which holds the solenoid on and the valve in that first position until the alternate position sensor is activated by the opposite end of stroke position of that piston (or any other piston used) which thereby unlatches the relay removing power from the solenoid and allows its spring return to the opposite position to hold the valve in its alternate and second position. This embodiment requires an electric supply, but a rechargeable battery or plug in batter pack can be used to allow the desired portability of the unit away from any power supplies and without connection to the electrical systems of the vehicles being serviced. Many other valve types can be used to provide same or the equivalent function, such as the use of two two-position three way valves, one for each end of the control valve which alternatingly provides pressure and vent to waste for each sensed piston end of stroke. One could also use a equivalent selection and arrangement of two position two-way valves such as simple solenoid operated on/off valves, or even a selection of check valves and/or priority valves which attain the same functional results without the same exact, specific structure. What is important is the overall function of the valve configuration, best referred to as a valve control system or configuration, rather than the particular and specific types of valves used and their arrangement and configuration.
In addition, one could use a compressed air powered pilot valve and fluid control valve, with the pilot valve in the cylinder block or at each cylinder head with spring return or equivalent operated by compressed air and which alternatingly routes compressed air and venting to each end of the fluid control valve. Any needed compressed air could be provided to and stored in an onboard pressure tank of the fluid exchange unit and this would still allow the highly desired portability within or around the service center.
It is understood that even though numerous characteristics and advantages of the present invention have been disclosed in the foregoing description, the disclosure is illustrative only and changes may be made in detail. Other modifications and alterations are within the knowledge of those skilled in the art and are to be included within the scope of the appended claims. | This invention provides a fluid system for exchanging used hydraulic fluid with fresh hydraulic fluid in an accessed hydraulic circuit. One particular application provides an exchange apparatus for exchanging fluids of the type found in motor vehicle hydraulic circuits. The exchange apparatus may utilize pressurized spent fluid flow as a fluid power medium to activate the auto-replenishing fluid exchanger system to replace the spent fluid with fresh fluid at equalized flow rates. Alternatively, the exchange apparatus may utilize pressurize fresh fluid as a fluid power medium to activate the exchange system. Additional power may be supplied by an external boost pump to supplement the flow of fluid. | 5 |
BACKGROUND OF THE INVENTION
It is often necessary to establish an electrical connection among electrical leads at various loci within a housing containing a device. The leads may emanate from elements within the housing or may lead into the housing from devices situated outside the housing for connection with elements within the housing. It is cumbersome, time consuming, and labor intensive to effect solder connection among leads within a housing. Further, such solder connections may require rework (in the case of a cold solder joint), or may otherwise provide substandard electrical connection because of such factors as vibration, heat, impurities, or the like.
It would be useful to provide a structure which permits electrical connection among a plurality of leads at a plurality of loci in a housing during assembly of the housing. Mechanical imposition of a bridging structure among selected electrical leads provides a structure for effecting such electrical connection during assembly.
It would also be useful to have such a structure which may be selectively employed for effecting differing electrical connections at different loci, depending upon the apparatus with which it is employed.
SUMMARY OF THE INVENTION
An improved system for selectively effecting electrical connection intermediate a plurality of electrical leads at a plurality of loci in a housing. The housing includes a first housing portion and a second housing portion configured to engage in a predetermined orientation during assembly of the housing. The system comprises an electrical bridging member located in one housing portion of the first housing portion and the second housing portion. The bridging member has a plurality of bias units, each of which is situated substantially at a respective locus of the plurality of loci. The system further comprises a bearing member which is located in the other housing portion and includes a plurality of urging units; there is a respective urging unit substantially in register with each respective locus when the first housing portion and the second housing portion are in the predetermined orientation. The plurality of urging units cooperate with the plurality of bias units during assembly to engage each respective bias unit with a respective electrical lead of the plurality of electrical leads at each respective locus to selectively electrically connect the respective electrical leads.
Such a structure facilitates orientation of components to effect housing assembly and electrical connection with a straightforward linear pressing motion. Such simple motions are particularly useful for automatic implementation.
It is, therefore, an object of the present invention to provide an improved system for selectively effecting electrical connection at a plurality of loci in a housing which may be automatically implemented.
It is a further object of the present invention to provide an improved system for selectively effecting an electrical connection in a plurality of loci in a housing which is configured to selectively accommodate a plurality of different applications with a single structure.
Further objects and features of the present invention will be apparent from the following specification and claims when considered in connection with the accompanying drawings illustrating the preferred embodiment of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of one housing portion appropriately configured for employment of the present invention.
FIG. 2 is a partially sectioned side view of the housing portion illustrated in FIG. 1, viewed along section 2--2 of FIG. 1, engaged with another housing portion to form a housing assembly.
FIG. 3 is a detail of a portion of the bridging member employed in the invention illustrated in FIGS. 1 and 2.
FIG. 4 is a detail of a portion of the invention illustrated in FIGS. 1-3, showing two housing portions poised for assembly.
FIG. 5 is a partially sectioned detail view of the invention illustrated in FIGS. 1-3 showing two housing portions partially engaged.
FIG. 6 is a partially sectioned detail view of the invention illustrated in FIGS. 1-3 showing two housing portions fully engaged.
FIG. 7 is a partially sectioned detail view of the invention illustrated in FIGS. 1-3 similar to the view illustrated in FIG. 5, but illustrating the effect of a distorted contact member during assembly of the housing.
FIG. 8 is a perspective schematic view of portions of a first alternate embodiment of the present invention.
FIG. 9 is a perspective schematic view of portions of a second alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a top plan view of one housing portion appropriately configured for employment of the present invention. In FIG. 1, a housing portion 10 includes a base section 12, a peripheral skirt 14, tab receiving latch mechanisms 16, a plurality of protrusions 18, and a plurality of apertures 20. Protrusions 18 and apertures 20 are representatively indicated in FIG. 1. Housing portion 10 is preferably manufactured of molded plastic material; the size, shape, and location of the various protrusions 18 and apertures 20 may be of significant variety to accommodate different particular uses for housing portion 10 such as switch housing, motor housing, or the like, as is within the capability of those skilled in the art of molding plastic materials. Tab receiving mechanisms 16 are configured and located appropriately to receive tabs from a substantially mating other housing portion (not shown in FIG. 1) to provide an assembled housing of two housing portions such as housing portion 10. Such an assembled housing may be configured to contain a mechanism or device 21 (shown schematically in FIG. 1) in a cavity established intermediate the two housing portions making up the housing.
Included in housing portion 10 among the various protrusions 18 and apertures 20 is an electrical connection system 22. Electrical connection system 22 includes buttressing protrusions 24, 26 which support a bridging contact member 28 generally adjacent electrical leads 30, 32.
In order to facilitate understanding the present invention, like elements will be labeled using like reference numerals in the various figures.
FIG. 2 is a partially sectioned side view of the housing portion illustrated in FIG. 1, viewed along section 2--2 of FIG. 1, engaged with another housing portion to form a housing assembly. In FIG. 2, housing portion 10 is engaged with a housing portion 11. Housing portion 11 engages housing portion 10 substantially atop peripheral skirt 14 above base section 12 of housing portion 10. Electrical connection system 22 is illustrated in side view in FIG. 2 revealing protrusion 26 as having a substantially trapezoidal profile. Bridging contact member 28 has a curved biased profile in predetermined areas (see contact members 40, 42; FIG. 3), and is preferably manufactured of a metal having spring bias properties when bent appropriately. Bridging contact member 28 is, in the assembled housing assembly 13 illustrated in FIG. 2, urged against electrical lead 32 by a pin member 34. Pin member 34 is preferably integrally formed with housing portion 11. Housing portion 11 has a base section 15 with which a plurality of protrusions 17 and apertures 19 are associated. Pin member 34 extends from base section 15 of housing portion 11, and has an integral buttressing structure 36. Buttressing structure 36 provides strength and rigidity to pin member 34 during assembly of housing assembly 13 by engagement of housing portions 10, 11. In the assembled orientation illustrated in FIG. 2, pin member 34 is situated substantially adjacent electrical lead 32 with bridging contact member 28 intermediate pin member 34 and electrical lead 32. Thus, a contact member 42 of bridging contact member 28 (described in greater detail in connection with FIG. 3) is urged against electrical lead 32 by pin member 34 when housing assembly 13 is assembled by appropriately engaging housing portions 10, 11. Similarly, a matching pin member (not shown in FIG. 2) urges a matching contact member 40 (see FIG. 3) of bridging contact member 28 against electrical lead 30 (see FIG. 1) to effect electrical connection between bridging member 28 and electrical lead 30. Since bridging member 28 is electrically continuous, such urging by pin member 34 and its matching pin member associated with electrical lead 30 effects electrical connection intermediate electrical leads 30, 32.
Thus, any component electrically connected to electrical lead 30 is electrically connected to a component connected with electrical lead 32 by the mere engagement of housing portions 10, 11 to form housing assembly 13; no other manufacturing step, such as soldering, application of conducted epoxy adhesive, or the like is required to effect that electrical connection.
FIG. 3 is a detail of a portion of the bridging member employed in the invention illustrated in FIGS. 1 and 2. In FIG. 3, electrical connection system 22 is illustrated as including bridging contact member 28 mounted substantially adjacent but not in electrical contact with electrical leads 30, 32. Bridging contact member 28 includes a base member 38 and integral stamped bearing members or contact members 40, 42. Contact members 40, 42 are electrically continuous with base member 38 and, preferably, are stamped from a blank electrically conductive metal component in a manner to integrally form base member 38 and contact members 40, 42. Mounting dimples 44 provide mechanical interference between protrusion 24 and bridging contact member 28 to ensure bridging contact member 28 remains in place during assembly. Additionally (or, alternatively) bridging contact member may be screw mounted, or heat staked, or plastic pin mounted, or mounted to protrusion 24 by other mountings known in the art for fixing a part to a plastic component.
FIG. 4 is a detail of a portion of the invention illustrated in FIGS. 1-3, showing two housing portions poised for assembly. In FIG. 4, housing portion 11 is poised adjacent housing portion 10, substantially in register with housing portion 10, and ready for engagement to form a housing assembly, such as housing assembly 13 of FIG. 2. Pin member 34 is generally in register with a location adjacent contact member 42.
FIG. 5 is a partially sectioned detail view of the invention illustrated in FIGS. 1-3 showing two housing portions partially engaged. In FIG. 5, housing portion 11 is close to full engagement with housing portion 10 in the process of forming a housing assembly, such as housing assembly 13 of FIG. 2. In FIG. 5, pin member 34 is in abutting relation with contact member 42, with there remaining some distance available for movement of housing portion 11 toward housing portion 10 in assembling a housing assembly.
FIG. 6 is a partially sectioned detail view of the invention illustrated in FIGS. 1-3 showing two housing portions fully engaged. In FIG. 6, housing portion 11 is fully engaged with housing portion 10 to form a housing assembly 13. Pin member 34 has displaced contact member 42 toward electrical lead 32, urging contact member 42 into physical and, consequently, electrical contact with electrical lead 32. In FIG. 6, it is illustrated that pin member 34 may have a resilient property in the fully engaged orientation of housing portions 10, 11. This resilient property results in pin member 34 flexing away from contact member 42 in the fully engaged orientation illustrated in FIG. 6. Such a resilient property is optional and is not required in the design of the present invention. Such a resilient property which results in a bending of pin member 34 away from electrical lead 32 and contact member 42 provides a sort of overtravel feature and lends some manufacturing tolerance forgiveness in forming the various components of the present invention. 0f course, an important feature of the invention is that pin member 34 travel substantially parallel with electrical lead 32 during assembly of housing portions 10, 11 and displaces contact member 42 into physical and electrical contact with electrical lead 32. Another pin member, similar to pin member 34, urges contact member 40 (FIG. 3) toward an electrical lead 30 (FIGS. 1, 3) to couple electrical leads 30, 32 in electrical common through contact members 40, 42 and base member 38 (FIG. 3).
FIG. 7 is a partially sectioned detail view of the invention illustrated in FIGS. 1-3 similar to the view illustrated in FIG. 5, but illustrating the effect of a distorted contact member during assembly of the housing. In FIG. 7, housing portion 11 is in initial engagement with housing portion 10. Contact members 40, 42 are not equally oriented with respect to base member 38 so that a pin member similar to pin member 34 (not shown in FIG. 7) engages contact member 40 at a different time during assembly of housing portions 10, 11 than the time at which pin member 34 engages contact member 42. As engagement of housing portions 10, 11 continues, each of contact members 40, 42 are eventually urged toward their respective electrical leads 30, 32 to effect electrical in-common connection through base member 38. Thus, even if manufacturing tolerances permit uneven displacement of contact members 40, 42 from base member 38 (or if such uneven displacement occurs during handling, assembly, or other operations) the structure of the present invention is forgiving of such differences and operates to correct those differences to uniformly urged contact members 40, 42 against their respective electrical leads 30, 32 when housing portions 10, 11 are engaged.
FIG. 8 is a perspective schematic view of portions of a first alternate embodiment of the present invention. In FIG. 8, a pin array 50 is illustrated comprising a base member 52 and a plurality of pins 54, 54'. In substantial register with pin array 50 is a contact array 56 which includes a base member 58 and a plurality of contact members 60. Thus, each respective pin 54, 54' is aligned with a respective contact member 60 along a respective axis 62. Pins 54' are indicated in phantom to indicate that they may be removed from pin array 50 after manufacture (e.g. by breaking off or cutting off a pin 54') or may be omitted from pin array 50 during manufacture. By such a configuration, a single pin array 50 may be tooled up to be produced in the configuration illustrated in FIG. 8 but may, for particular applications, have one or more of pins 54' removed because, in the particular application for which those pins 54' are removed, its respective contact member 60 is not to be electrically engaged.
FIG. 9 is a perspective schematic view of portions of a second alternate embodiment of the present invention. In FIG. 9, a pin array 70 is illustrated as including a base member 72 and a plurality of pins 74, 74'. In the second alternate embodiment illustrated in FIG. 9, base member 72 is a generally serpentine base member having a plurality of segments non-linearly arranged. Consequently, there is provided a contact array 76 which includes a base member 78 and a plurality of contact members 80; base member 78 is serpentinely arranged generally in register with pin array 70 so that each respective contact member 80 is aligned with a respective pin 74, 74' along a respective axis 82.
In a manner similar to the alternate embodiment indicated in FIG. 8, selected pins 74' may be removed from an already standardly manufactured (e.g., molded) base member 72 so that selected respective contact members 80 will not be displaced when a housing portion fixedly arranged with base member 72 is engaged with a housing portion fixedly arranged with respect to base member 78 during assembly of the two housing portions to form a housing assembly, as generally described in connections with FIGS. 1-3. Such a selectively removable pin 74' capability or structure provides a programmability feature for the present invention in all of its embodiments illustrated in FIGS. 1-9.
It is to be understood that, while the details, drawings and specific examples given describe preferred embodiments, they are for the purpose of illustration, that the apparatus of the invention is not limited to the precise details and conditions disclosed, and that various changes may be made therein without departing from the spirit of the invention which is defined by the following claims. | An improved system for selectively effecting electrical connection intermediate a plurality of electrical leads at a plurality of loci in a housing. The housing includes a first housing portion and a second housing portion configured to engage in a predetermined orientation during assembly of the housing. The system includes an electrical bridging member located in one housing portion. The bridging member has a plurality of bias units, each of which is situated substantially at a respective locus of the plurality of loci. The system further includes a bearing member which is located in the other housing portion and includes a plurality of urging units; there is a respective urging unit substantially in register with each respective locus when the first housing portion and the second housing portion are in the predetermined orientation. The plurality of urging units cooperate with the plurality of bias units during assembly to engage each respective bias unit with a respective electrical lead of the plurality of electrical leads at each respective locus to selectively electrically connect the respective electrical leads. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an axial flow fan of an air conditioner, in which the number of blades is two, and each blade has a part from the hub to a predetermined portion of the blade among a whole part from the hub to an outer end of the blade which is equally applied at a predetermined rake angle, and the other part from the predetermined portion of the blade to the outer end of the blade which is raised in a direction of a pressure surface of the blade, and a ratio of an inner diameter and an outer diameter of the axial flow fan is between about 0.35 and about 0.4.
[0003] 2. Background of the Related Art
[0004] In general, an air conditioner is mounted therein with a refrigerating cycle system composed of a compressor, a condenser, a capillary tube, an evaporator and a heat exchanger. The air conditioner is an apparatus for properly sending cold air formed at the evaporator or warm air generated at the condenser according to an indoor condition, and thus genially maintaining indoor atmosphere.
[0005] The air conditioner may be divided into a window type air conditioner where the refrigerating cycle system is mounted in a single body, a spilt type air conditioner where an indoor unit and an outdoor unit are separated and installed indoors and outdoors respectively, and so forth. Particularly, the spilt type air conditioner is again divided, according to an installation method, into a wall-mounted type, a permanent-mounted type (including a package air conditioner), a ceiling-mounted type, a ceiling-embedded type and so on. Especially, the indoor unit of the spilt type air conditioner may has a structure capable of alternatively using the wall-mounted type and the permanent-mounted type and being simultaneously applied as the ceiling-mounted type according to need of a user, which is referred to as a convertible type indoor unit.
[0006] FIG. 1 schematically shows a general air conditioner.
[0007] Referring to FIG. 1 , the conventional air conditioner is composed of an outdoor unit 20 which is disposed outdoors and exchanges heat with outdoor air, an indoor unit 10 which is disposed indoors and conditions indoor air, and a connecting line 30 which connects the outdoor unit and the indoor unit with each other.
[0008] To be more specific, the outdoor unit 20 is a means for converting a gas refrigerant of low temperature and low pressure, which is inputted from the indoor unit 10 by exchanging heat with the outdoor air, into a liquid refrigerant of low temperature and low pressure, and is composed of a compressor 11 , a condenser 12 and an expansion valve 13 .
[0009] Further, the compressor 11 is a component for converting the gas refrigerant of low temperature and low pressure, which is inputted from the indoor unit 10 , into the gas refrigerant of high temperature and high pressure, and the condenser 12 is a component for converting the gas refrigerant of high temperature and high pressure into a liquid refrigerant of middle temperature and high pressure, and the expansion valve 13 is a component for converting the liquid refrigerant of middle temperature and high pressure into the liquid refrigerant of low temperature and low pressure.
[0010] Here, the condenser 12 is a component for directly exchanging the heat with the outdoor air, and has a separate fan for introducing the outdoor air.
[0011] Meanwhile, the indoor unit 10 lowers an indoor temperature by means of evaporation, which occurs when the liquid refrigerant of low temperature and low pressure introduced from the outdoor unit 20 is converted into the gas refrigerant of low temperature and low pressure.
[0012] The indoor unit 10 is composed of an evaporator 21 and a fan 21 a , wherein the evaporator 21 converts the liquid refrigerant of low temperature and low pressure into the gas refrigerant of low temperature and low pressure. The connecting line 30 is a component for connecting the indoor unit 10 and the outdoor unit 20 to circulate the refrigerant, and is properly disposed according to a distance between the outdoor unit 10 and the indoor unit 10 .
[0013] As set forth above, the outdoor unit 20 of the split-type air conditioner includes the compressor, the condenser, a cooling fan (hereinafter, referred to as “axial flow fan”) which usually generate many noises, and a driving motor for rotating the axial flow fan. The indoor unit 10 includes the evaporator 21 and the blow fan 21 a , and performs refrigeration and circulation of the indoor air.
[0014] FIG. 2 is a perspective view illustrating a general split type air conditioner.
[0015] As shown in FIG. 2 , the indoor unit 10 and the outdoor unit 20 are connected to each other by the connecting line 30 .
[0016] Meanwhile, the axial flow fan 40 , as shown in FIG. 3A , has a hub 42 coupled to a rotational shaft of the driving motor (not shown), and a plurality of blades 44 formed on an outer circumferential surface of the hub 42 , wherein the hub 42 is integrally formed with the blades 44 .
[0017] When the axial flow fan 40 is rotated by the driving motor, a pressure difference is generated between front and rear sides of the plurality of blades 44 formed on the outer circumferential surface of the hub 42 .
[0018] This pressure difference generates a suction force capable of sucking up the air, thus sucking up the outdoor air toward the outdoor unit 20 through the suction. Thus, the outdoor air passes through the condenser 12 provided on an intake side of the outdoor unit. At this point, the outdoor air exchanges the heat with the gas refrigerant flowing through the condenser to condense the gas refrigerant into a liquid state, and then flows out outside the outdoor unit 20 through ventilation of the axial flow fan 40 .
[0019] As for characteristic factors determining a ventilation characteristic of the axial flow fan 40 , they are divided into two types: general factors such as the number of the blades 44 , a (outer) diameter D of the axial flow fan, a (outer) diameter d of the hub and so forth, and so-called blade factors such as a pitch angle β, a peak point of the camber P, a maximum quantity of the camber MC, a length of a chord, a sweep angle α and so forth at the blade, which will be described below with reference to FIGS. 3A and 3B .
[0020] The pitch angle β of the blade, as in FIG. 3B , is an angle between a flow direction of the fluid or the air (x-axis in the figure) and a straight line, namely a chord, running from a leading edge (L.E) of the blade 44 and its trailing edge (T.E).
[0021] Here, the quantity of the camber refers to a length joining the camber (a central line across a cross section of the blade) and the chord. The maximum point of the camber quantity, i.e., the maximum quantity of the camber MC, as in FIG. 3B , refers to the camber quantity between the L.E. of the blade 44 and the camber peak point P on the chord C running from the L.E to the T.E.
[0022] The sweep angle α refers to an angle between two lines that intersect, one of which is one which connects the center of an inner end of the blade 44 or the center of a portion where the blade 44 comes into contact with the hub 42 but goes with a curvature of the blade 44 , and the other is one (Y axis in the figure) which passes through the center (point) of the inner end of the blade 44 and the center (point) of the hub 42 .
[0023] Especially, the sweep angle α is a factor determining a noise of an airflow of the axial flow fan 40 . When the sweep angle α is great, a phase difference of the airflow between the hub 42 and a tip of the blade 44 becomes great. In contrast, when the sweep angle α is great, the phase difference of the airflow becomes small.
[0024] The phase difference of the airflow causes a phase difference between a noise generated at the outer end of the blade 44 and a noise generated at the inner end of the blade 44 . The greater this noise phase difference is, the lower a frequency of the airflow passing through the blade 44 becomes. Hence, the noise becomes lower.
[0025] And, the number of the blades 44 is an important factor determining the airflow noise generated when the axial flow fan 40 is operated.
[0026] One example of this conventional axial flow fan 40 is disclosed in Korean Patent Publication No. 2003-14960, titled AXIAL FLOW FAN OF OUTDOOR UNIT OF AIR CONDITIONER, previously filed by the present applicant and published as of Feb. 20, 2003. As for the disclosed axial flow fan of the outdoor unit of the air conditioner, it includes a hub 42 connected with a rotational shaft of a motor and a plurality of blades 44 integrally formed on an outer circumferential surface of the hub, wherein the number of the blades 44 is set to three, a whole outer diameter of the fan is set to 340±2 mm, and a diameter of the hub 42 is set to 100±2 mm.
[0027] Further, each blade 44 is configured so that the pitch angle β is linearly changed from the hub 42 to the end thereof in a range between 20 degrees and 37 degrees.
[0028] Each blade 44 is also configured so that the peak point of the camber P is formed at a point corresponding to 70% of the chord length in a direction from the L.E thereof to the T.E thereof, and that the maximum quantity of the camber MC is set to 0.5% within each radius from the hub 42 to the end of the blade 44 .
[0029] Further, the sweep angle α of each blade 44 has a range between 47 degrees and 49 degrees when a dimensionless radius coordinate is less than 0.3 and is linearly increased when the dimensionless radius coordinate exceeds 0.3 to have a range between 55 degrees and 57 degrees at the end of the blade.
[0030] For reference, the dimensionless radius coordinate is a factor for taking into consideration of performance of the axial flow fan only by the blades 44 except for the hub 42 , and is determined between 0 and 1 when a position where the blades and the hub come into contact with each other is set to 0, and the end of each blade 44 is set to 1.
[0031] The dimensionless radius coordinate is obtained by the follow formula. r=(R−Rh)/(Rt−Rh), where R is the length from the center of the axial flow fan (i.e. the center of the hub) to a certain position, Rh is the radius of the hub 42 , Rt is the length from the center of the axial flow fan (i.e. the center of the hub) to the end of each blade 44 , namely, the radius of the axial flow fan.
[0032] According to the axial flow fan 40 having three blades 44 in the outdoor unit of the foregoing air conditioner, as shown in FIGS. 4 and 5 , a pressure coefficient and constant pressure efficiency are enhanced as compared to another conventional axial flow fan having four blades. As a result, the motor for the axial flow fan having three blades can be also enhanced in operation efficiency at an operation point, and can be driven with a size smaller than that for another conventional axial flow fan having four blades. In addition, the motor for the axial flow fan having three blades is reduced by about 22% in consumption electrical power required for operation.
[0033] However, when the axial flow fan 40 is driven, a slip stream or wake component is generated at the L.E and T.E of the leading blade 44 , and a turbulent flow component is generated by separation on a negative pressure surface. These two components have influence on the trailing blade 44 , thus deteriorating the performance of the axial flow fan 40 , and simultaneously generating the noise by a turbulent flow.
SUMMARY OF THE INVENTION
[0034] Therefore, an objective of the present invention is to design an axial flow fan within an optimal design range capable of suppressing increase in intensity of a turbulent flow generated from a surface of each blade, increase in thickness of a boundary layer on the surface of each blade and disturbance of an airflow within a region of the hub.
[0035] It is another objective to provide an axial flow fan capable of remarkably reducing a noise within the predetermined frequency range (between about 300 Hz and about 1000 Hz) with respect to the same air volume as the conventional axial flow fan.
[0036] To achieve the above objective, the present invention provides an axial flow fan comprising a hub connected with a rotational shaft of a motor; and at least one blade contacting the hub, wherein the blade has a part from the hub to a predetermined portion of the blade among a whole part from the hub to an outer end of the blade, and the other part from the predetermined portion of the blade to the outer end of the blade, the part being equally applied at a predetermined rake angle, and the other part being raised in a direction of a pressure surface of the blade.
[0037] Further, the axial flow fan has a ratio of an inner diameter and an outer diameter of the axial flow fan between about 0.35 and about 0.4.
[0038] Therefore, according to the present invention, the axial flow fan can reduce the noise as low as possible and increase the pressure coefficient and the constant pressure efficiency compared to the conventional axial flow fan.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The above objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:
[0040] FIG. 1 schematically shows a general air conditioner;
[0041] FIG. 2 is a perspective view illustrating a general split type air conditioner;
[0042] FIGS. 3A and 3B are front and side views of a conventional axial flow fan, respectively;
[0043] FIG. 4 is a graph showing comparison of relation between a pressure coefficient and a flow rate coefficient in a conventional axial flow fan with that of another conventional axial flow fan;
[0044] FIG. 5 is a graph showing comparison of relation between constant pressure efficiency and a flow rate coefficient in a conventional axial flow fan with that of another conventional axial flow fan;
[0045] FIGS. 5A and 5B are front and side views of an axial flow fan according to the present invention, respectively;
[0046] FIGS. 7A and 7B show a state where blades are tilted on an outer circumferential surface of a hub at a certain rake angle in axial flow fans according to the prior art and the present invention;
[0047] FIG. 8 is a graph showing a state where a noise is changed according to a change of a solidity with respect to axial flow fans of the prior art and the present invention;
[0048] FIG. 9 is a graph showing a state where a noise is changed according to a change of a quantity of a camber with respect to axial flow fans of the prior art and the present invention;
[0049] FIG. 10 is graph showing relation between a (constant) pressure coefficient, a constant pressure efficiency and a flow rate coefficient with respect to axial flow fans of the prior art and the present invention; and
[0050] FIG. 11 is a graph showing comparison of a state where a noise is changed according to a change of a frequency of an axial flow fan of the present invention with that of an axial flow fan of the prior art.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0051] An exemplary embodiment of the present invention will now be described with reference to the accompanying drawings.
[0052] FIGS. 6A and 6B are front and side views of an axial flow fan according to the present invention, respectively. FIGS. 7A and 7B show a state where blades are tilted on an outer circumferential surface of a hub at a certain rake angle in axial flow fans according to the prior art and the present invention.
[0053] An axial flow fan 140 of an outdoor unit of an air conditioner according to the present invention is composed of a hub 142 connected with a rotational shaft 141 of a motor, and a plurality of blades 144 integrally formed on an outer circumferential surface of the hub 142 .
[0054] The axial flow fan 140 is configured so that the number of the blades is two, that a ratio of an inner diameter to an outer diameter (i.e. a ratio of the outer diameter of the hub and the outer diameter of the fan) is between about 0.35 and about 0.4, that a solidity, a ratio of the whole area of the fan 140 and an area of the blades, has a range of 0.85±0.05, and that a quantity of a camber of the hub 142 has a range of 5.0%±1.0%.
[0055] Hereinafter, a detailed description will be made on the axial flow fan of the outdoor unit of the air conditioner according to the present invention.
[0056] Meanwhile, when the axial flow fan 140 is driven, a slip stream or wake component may be generated at a leading edge (L.E) and a trailing edge (T.E) of the leading blade 144 , and a turbulent flow component may be generated by separation on a negative pressure surface. These two components may have influence on the trailing blade 144 , thus deteriorating performance of the axial flow fan 140 , and simultaneously generating a noise by a turbulent flow. Thus, the present invention aims at preventing the drawbacks of the axial flow fan 140 .
[0057] Further, the present invention is to suppress increase in intensity of the turbulent flow generated from a surface of each blade 144 , increase in thickness of a boundary layer on the surface of each blade 144 , and disturbance of an airflow within a region of the hub 142 .
[0058] In order to accomplish the objectives, the axial flow fan 140 is formed so that the number of the blades 144 is two, that the ratio of the inner diameter to the outer diameter (i.e. the ratio of the outer diameter of the hub and the outer diameter of the axial flow fan) is between about 0.35 and about 0.4, that the solidity, the ratio of the whole area of the fan 140 and the area of the blades, has the range of 0.85±0.05, and that the camber quantity of the hub 142 has the range of 5.0%±1.0%. With regard to this, the detailed configuration of the present invention is as follows.
[0059] The axial flow fan 140 of the outdoor unit of the air conditioner according to the present invention, as shown in FIG. 6A , is composed of the hub 142 connected with the rotational shaft 141 of the motor, and the plurality of blades 144 integrally formed on the outer circumferential surface of the hub 142 .
[0060] Here, the number of the blades 144 is set to two. The inner and outer diameter ratio of the axial flow fan 140 , i.e. the ratio of the outer diameter of the hub 142 and the outer diameter of the axial flow fan 140 , is set to a range between about 0.35 and about 0.40.
[0061] Further, the ratio of the whole area of the axial flow fan 140 and the area of the blades, i.e. the solidity, has the range of 0.85±0.05, and the camber quantity of the hub 142 has the range of 5.0%±1.0%. The solidity can be expressed by the following formula.
Solidity=(chord× Z )/2 πr
where 2πr: circumference length when a radius is r, chord: straight line joining the L.E of the blade with the T.E of the blade, Z: the number of blades.
[0063] Thus, a value of the solidity presented in the present invention may become a mean value from the hub and a tip, for example, an integral value.
[0064] For the axial flow fan 140 , as shown in FIGS. 7A and 7B , a rake base line of each blade 144 formed on the outer circumferential surface of the hub 142 is tilted from that formed horizontal to the outer circumferential surface of the conventional hub 42 by a rake angle between about 20 degrees and about 23 degrees. Here, the rake angle refers to an angle determining how much to tilt and form the blades 144 on the circumferential surface of the hub 142 .
[0065] As for a state where the blades 144 are formed on the outer circumferential surface of the hub 142 through the rake angle, as shown in FIGS. 7A and 7B , among the whole length from the outer circumferential surface of the hub 142 to the outer end (i.e. tip) of each blade 144 , a part from the outer circumferential surface of the hub 142 to a predetermined portion of each blade 144 is tilted at the rake angle, and the other part from the predetermined portion of each blade 144 and the tip of each blade 144 is provided with a bulge 146 protruded toward a pressure surface. The tip of each blade 144 has the same angle as the rake angle from the outer circumferential surface of the hub 142 to the predetermined portion of each blade 144 . In this manner, a profile of the axial flow fan 140 is formed as a whole.
[0066] In other words, when the section from the outer circumferential surface of the hub to the tip of each blade is divided into two sections, the first section performs rotational displacement at the identical angle, and the second section forms a non-linear angle raised toward the pressure surface. The tip (i.e. a section except for the two sections) is adapted to apply an identical value of the first section.
[0067] At this point, the outer diameter D of the axial flow fan is 460±2 mm, and the outer diameter d of the hub 142 is 170±2 mm.
[0068] Here, a pitch angle, a peak point of a camber, and a sweep angle of each blade 144 are the same as the pitch angle β, the peak point of the camber P, the maximum quantity of the camber MC, and the sweep angle α of the conventional blade 44 shown in FIGS. 3A and 3B . Now, the pitch angle, the peak point of the camber, and the sweep angle of each blade 144 will be described in detail below.
[0069] The pitch angle β of each blade 144 is configured to be linearly changed from the hub 142 to the end of the blade 144 within a range between 37 degrees and 20 degrees.
[0070] Each blade 144 is configured so that the peak point of the camber P is formed at a position corresponding to 70% of a length of a chord in a direction from the front end of the blade to the rear end of the blade, and that the maximum quantity of the camber MC is kept constant at a value of 0.5% within each radius from the hub 142 to the end of the blade 144 .
[0071] Furthermore, the sweep angle α of each blade 144 has a range between about 47 degrees and about 49 degrees when a dimensionless radius coordinate is less than 0.3 and is linearly increased when the dimensionless radius coordinate exceeds 0.3 to have a range between about 55 degrees and about 57 degrees at the end of the blade.
[0072] A change of the noise generated from the axial flow fan configured as set forth above will be described below.
[0073] FIG. 8 is a graph showing a state where a noise is changed according to a change of a solidity with respect to axial flow fans of the prior art and the present invention. FIG. 9 is a graph showing a state where a noise is changed according to a change of a quantity of a camber with respect to axial flow fans of the prior art and the present invention. FIG. 10 is graph showing relation between a (constant) pressure coefficient, a constant pressure efficiency and a flow rate coefficient with respect to axial flow fans of the prior art and the present invention. FIG. 11 is a graph showing comparison of a state where a noise is changed according to a change of a frequency of an axial flow fan of the present invention with that of an axial flow fan of the prior art.
[0074] As seen from the foregoing description and the drawings, the solidity applied to the present invention has a range of 0.85±0.05 and the camber quantity of the hub has a range of 5.0%±1.0%.
[0075] In contrast, the solidity applied to the prior art (Z=3) has a relatively great value compared to that of the present invention, and the camber quantity of the hub has a relatively small value.
[0076] The following description will be made with reference to FIGS. 10 and 11 .
[0077] In the graph of FIG. 10 , an upper line shows a comparison of relation of the (constant) pressure coefficient and the flow rate coefficient in the axial flow fan 140 with that of the conventional axial flow fan 40 , while a lower line shows a comparison of relation of the constant pressure efficiency and the flow rate coefficient in the axial flow fan 140 with that of the conventional axial flow fan 40 .
[0078] For the axial flow fan 140 according to the present invention, the noise change was measured depending on the change of the solidity as the ratio of the whole area of the fan 140 to the area of the blades. It was found that as a result of the measurement, as shown in FIG. 8 , when the ratio of the whole area of the fan 140 to the area of the blades, i.e. the solidity, was about 0.87, the noise was the lowest. Further, the noise change was measured depending on the change of the camber quantity of each blade of the axial flow fan 140 . It was found that as a result of the measurement, as shown in FIG. 9 , when the camber quantity of the blade 144 was about 0.5%, the noise was lowest.
[0079] For the axial flow fan 140 according to the present invention, it can be seen that as shown in FIG. 10 , the pressure coefficient and the constant pressure efficiency were enhanced over the conventional axial flow fan 40 , and that the operation efficiency was also enhanced at the operation point according to the enhancement of the pressure coefficient and the constant pressure efficiency of the axial flow fan 140 as set forth above.
[0080] Further, FIG. 11 is a graph showing comparison of a state where a noise is changed according to a change of a frequency of an axial flow fan of the present invention with that of an axial flow fan of the prior art. As shown in FIG. 11 , it can be seen that when having an air volume equal to that of the conventional axial flow fan 40 , the axial flow fan 140 was subjected to great reduction of the noise in a range between about 300 Hz and about 1000 Hz.
[0081] As set forth above, the present invention relates to the axial flow fan configured so that the number of the blades is two, that a predetermined rake angle is kept constant in the part from the hub to the predetermined portion of the blade among the whole part from the hub to the outer end of the blade and is increased in the pressure surface direction in the other part from the predetermined portion of the blade to the outer end of the blade, and the ratio of the inner diameter to the outer diameter is between about 0.35 and about 0.4.
[0082] Therefore, the axial flow fan of the present invention is designed within an optimal design range (that the solidity, the ratio of the whole area of the axial flow fan and the area of the blades, is about 0.87 and that the camber quantity of the hub is about 5.0%), for example, capable of suppressing increase in intensity of the turbulent flow generated from the surface of each blade, increase in thickness of the boundary layer on the surface of each blade and disturbance of the airflow within the region of the hub. As a result, the axial flow fan of the present invention can reduce the noise as low as possible and increase the pressure coefficient and the constant pressure efficiency compared to the conventional axial flow fan.
[0083] Further, the axial flow fan of the present invention can remarkably reduce the noise within the predetermined frequency range (e.g. between about 300 Hz and about 1000 Hz) with respect to the same air volume as the conventional axial flow fan.
[0084] While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
[0085] For example, the axial flow fan of the present invention may be applied to a refrigerator or other apparatuses for condensing and evaporating a refrigerant.
[0086] Therefore, the above-mentioned description is simply illustrative but not intended to restrict the invention by limitations of the claims. | Disclosed is a axial flow fan of an outdoor unit of an air conditioner. The axial flow fan comprises a hub connected with a rotational shaft of a motor; and at least one blade contacting the hub, wherein the blade has a part from the hub to a predetermined portion of the blade among a whole part from the hub to an outer end of the blade, and the other part from the predetermined portion of the blade to the outer end of the blade, the part being equally applied at a predetermined rake angle, and the other part being raised in a direction of a pressure surface of the blade, and wherein a ratio of an inner diameter and an outer diameter of the axial flow fan is between about 0.35 and about 0.4. | 5 |
BACKGROUND OF THE INVENTION
[0001] The invention is directed to a lighting system, particularly a system of indoor lights.
[0002] Particularly given indoor lights, the multi-faceted lighting jobs that occur indoors and the frequently changing spatial prescriptions, for example given recessed lights, lead to what are in part extremely different forms and light-oriented designs. For example, lights for picture screen workstations require a shielding, i.e. a lowering of the average luminous intensity at the light exit face above a boundary angle to the perpendicular relative to the light exit face in a plurality of planes for a shielding angle of, for example, 60° as required by the applicable standards and proposed standards, so that the limit value of the radiant intensity according to these standards and proposed standards lies at 200 cd/m 2 , 500 cd/m 2 or 1000 cd/m 2 . For other types of lights, for example wall washers or ceiling washers, completely different demands are made of the distribution curve of the light intensity. Accordingly, the light technology of previous lights had to be individually adapted to the respective function and, potentially, also had to be adapted to the respective spatial prescriptions. For example, the shielding is conventionally achieved by the reflector walls and/or by a lamella grid. A change of the shielding angle in the direction perpendicular to the lamp axis requires, for example, a change in the structural height of the electrical devices, which requires a change in the housing. Likewise, the remodeling of a directly emitting lamp into an indirectly emitting lamp according to the conventional technique requires a complete replacement of the reflector. Accordingly, a great number of individual parts had to be manufactured for the individual lights and this increased the manufacturing costs.
SUMMARY OF THE INVENTION
[0003] An object of the invention is to make a possibility available as to how lights, particularly indoor lights of various types, can be more rationally manufactured.
[0004] This object is inventively achieved by a light system composed of a plurality of lights having different light emission properties, particularly recessed lights, built-in lights and/or pendulum lights that respectively have at least one hollow light guide with a cavity into which light from one or more lamps is beamed and has at least one light output device for outputting light from the hollow light guide to a light exit face. The light output device comprises at least one light-permeable element, particularly a light-transmissive plate, having a boundary surface between two media with a different refractive index that is provided with a light-refractive structure in at least one plane directed perpendicularly to the light exit face such that the light intensity distribution curve of the light emerging at the light exit face is influenced in this plane. The lamps comprise a supporting structure, particularly a housing, at or in which at least one optically effective element that influences the beam path of the light output by the lamp, particularly a light output device, a cap reflector or at least one other reflective and/or light-transmissive element of the hollow light guide and/or an input reflector for coupling light from the lamp into the hollow waveguide is attached. The improvements are that at least one optically effective component that influences the beam path of the light emitted by the lamp, particularly a reflective or light-refractive element, is a prefabricated component for every lamp that is dimensioned so that it can be attached and/or installed as optically effective element at or, respectively, in each supporting structure of a lamp of the system.
[0005] The invention is particularly directed to light systems wherein at least some of the lights, particularly all lights, have the lamp or lamps arranged outside the hollow light guide and couple light into the hollow light guide from the outside. The light input in the lamps or lights of the system can, m particular, occur laterally proceeding from a narrow side.
[0006] What is to be understood by a light system in this context is a group or set of real lights that are respectively constructed as described above and that have the common feature in structural terms that at least one optically effective component having said properties can be employed at the support structure of each light. Various lights can comprise mutually corresponding components at corresponding locations of the respective support structure for which the dimensions relevant for the mounting, for example length and width, are identical but that have different optical properties. The totality of the specific lamps forms the light system.
[0007] The aforementioned light-refractive structure that deflects light in a directed fashion and influences the light intensity distribution curve in a plane can, in particular, be a light-refractive structure that essentially prevents a light emission above a limit angle in at least one plane perpendicular to the light exit surface so that a shielding of light emerging at the light exit face is produced in this plane.
[0008] What is understood by a shielding is the lowering of the average radiant intensity at the light exit face above a boundary angle to a perpendicular to the light exit face below a predetermined limit value, for example 200 cd/m 2 , 500 cd/m 2 or 1000 cd/m 2 .
[0009] The aforementioned light-refractive structure can, however, also influence the distribution curve of the light intensity in some other way. For example, a wide-angle light intensity distribution can be produced with a suitable selection of the structure elements, wherein the light intensity distribution curve has a minimum in the region of 0° and has a pronounced maximum in the region between 0° and 90°, whereby the position of the maximum is dependent on the elements of the light-refractive structure employed but is also probably dependent on other components such as, for example, the cap reflector of a hollow light guide. Dependent on the design of the lamp, such a light-angle light intensity distribution can be symmetrical or asymmetrical.
[0010] The invention can provide that, in every lamp, at least a cap reflector, an element of the light output device having a light-refractive structure and/or an input reflector is a prefabricated component that is dimensioned so that it can be attached and/or installed at or, respectively, in each support structure.
[0011] It can be provided that, for all lamps of the system, at least one element of the light output device provided with a light-refractive structure, a cap reflector and/or an input reflector is dimensioned essentially the same in view of the dimensions relevant for the installation or, respectively, attachment in the support structure and preferably comprises the same installation or attachment dimensions overall.
[0012] The relevant dimensions are dependent on the details of the support structure. For example, the height of the component can vary when the support structure or the design of the lamp overall makes no prescription with respect to this dimension.
[0013] The invention provides a system whose elements are constructed in modular fashion, whereby elements of this module can, for example, be input reflectors, cap reflectors and/or prism plates as well as, potentially further elements that can be employed in all lamps of the system.
[0014] In particular, the invention can provide that a light-technical function unit such as light input device or a light output device is modularly constructed of a plurality of elements. For example, the light input from the lamps into the hollow light guide can occur by means of a plurality of input reflectors having standardized dimensioned that are attached to one another in the longitudinal direction of the lamp. Likewise, the light output device can be composed of a plurality of plates having light-refractive structures that have standardized dimensions. Preferably, such a light-technical unit is constructed of elements which have the same dimensions.
[0015] In the inventive light system, a plurality of lamps can have the same support structure and can respectively differ on the basis of one or more optically effective components secured to the support structure that respectively have the same dimensions but exhibit different light-oriented properties.
[0016] The optically effective component can, in particular, be a reflective or a light-refractive element, for example an input reflector, a cap reflector of the hollow light guide and/or a light output device or, respectively, a prism plate or prism foil.
[0017] It can be provided in an inventive lamp system that one or more first lamps comprise an exclusively reflective cap reflector and one or more second lamps comprise partially light-transmissive cap reflector for the output of an indirect light part. The cap reflector of the first lamps is dimensioned so that it can be attached and/or installed at, or, respectively, in the support structure, and the cap reflector of the second lamps is dimensioned so that it can be attached and/or installed at or, respectively, in the support structure. By exchanging the cap reflector, an exclusively directly emitting lamp can, for example, be converted into an indirectly emitting lamp and vice versa.
[0018] It can also be provided that at least two lamps of the system comprise a cap reflector that is respectively dimensioned such that it can be inserted into or attached to the support structure of the respectively other lamp. The cap reflector of the one lamp comprises different reflection properties from the cap reflector of the other lamp, particularly in view of the distribution of the reflected light. As a result of the modification of the reflection properties of a cap reflector, the light intensity distribution can be among the things that is influenced. In particular, asymmetrical light intensity distributions can be achieved in this way.
[0019] The inventive lamp system can also provide that at least two lamps of the system have one or more plates in the respective light output device having a light-refractive structure as a component part of the light output device. These plates are dimensioned so that they can be introduced into or attached to the support structure of the respectively other lamp and the plates of the one lamp have a different light-refractive structure than the plates of the other lamp.
[0020] Instead of a plate, some other planar element having a light-refractive structure can be employed, for example a foil, and this element should preferably be stable in shape or be a component part of a unit that is stable in shape. That stated below with respect to plates applies analogously to foils as well, even when this is not expressly mentioned.
[0021] The light-refractive structure can, for example, be formed into the plates or fashioned in a foil that is attached onto the plate, for example glued on.
[0022] For example, it is thus possible by replacing the prism plate or, respectively, prism plates (or a corresponding foil) to convert a lamp having a shielding for picture screen work stations into a lamp having a wide-angle light intensity distribution or a lamp having an asymmetrical light intensity distribution, a wall washer, a ceiling washer or a wall fixture.
[0023] In particular, it can be provided that at least one plate of the one lamp comprises the same dimensions relevant for the installation or attachment to the support structure as a plate of the other lamp and preferably comprises the same installation or attachment dimensions.
[0024] The plates or foils having the light-refractive structure need not necessarily be directly secured to the support structure of the respective lamp; rather, for example, they can also be connected to a carrying plate that is in turn connected to the housing or to some other support structure. The dimensions of the plate must then enable a mounting into a corresponding opening of the hollow light guide.
[0025] It can be particularly provided that a plate or plates of the one lamp comprise the same length and width as the plate or, respectively, plates of the other lamp.
[0026] The invention can also provide that an input reflector of one or more first lamps is different from an input reflector of one or more second lamps and is dimensioned so that the input reflector of the first lamps can be attached and/or installed at or, respectively, in the support structure of the second lamps and vice versa.
[0027] It can also be provided that an input reflector of the first lamps completely reflects light into the hollow light guide, and the input reflector of the second lamps allows light to partially pass or reflects light partially past the hollow light guide for output of an indirect light part.
[0028] The design of the reflector, whether a cap reflector or an input reflector, for outputting an indirect light part can ensue in various ways. For example, a second light output device having a light-refractive structure can be provided in the reflector, and this device partially reflects light and partially couples light out. The reflector can also have either perforations having different dimensions or surfaces having different transmission properties. For example, an input reflector can be constructed so that it outputs the light of the lamp through an opening extending in its longitudinal direction.
[0029] It is provided in a specific lamp system that, for a group of lamps, the light output face via which light is coupled out from the hollow light guide is different for at least two different lamps of this group. The light output device for at least a part of the lamps of the group has comprises plates arranged side-by-side that are respectively provided with a light-refractive structure that deflects light in a directed fashion, particularly a light-refractive structure generating a shielding, so that at least one plate having a light-refractive structure deflecting light in the directed fashion has the same basic shape and the same relevant dimensions, for example length and width for all lamps of this group as a corresponding plate of all other lamps of the group.
[0030] The group can, in particular, also be identical to the entire lamp system, i.e. comprise all lamps of the system.
[0031] It can thereby be provided that all plates of a lamp of the group, which plates have a light-refractive structure for deflecting light in a directed fashion, have the same basic shape and the same dimensions as the plates with a light-refractive structure of a different structure for all other lamps of the group.
[0032] According to this embodiment, the light output device, which have different dimensions for different lamps, are at least partially constructed of standardized plates. Preferably, the light exit openings are likewise standardized so that they can be constructed of a given plurality of standardized plates with fixed dimensions carrying a light- refractive structure. This, however, will not be capable of being standardized always and for all light-oriented applications of the lamp system. In order to compensate for discrepancies between the dimensions of the standardized plate and the dimensions of the light exit face, for example, a prism plate can be cut during mounting, so that the prism plates that are provided can be inserted overall into the light exit opening.
[0033] The invention can also provide that the plate or plates are separated from one another or from the housing of the hollow light guide for at least one lamp of the system by a plurality of spacer elements, particularly frames or frame elements, which have different dimensions.
[0034] In this way, it is possible to compensate for discrepancies between the dimensions of the prescribed light output face or, respectively, light exit face and the dimensions prescribed by the standardized plates. In order, for example, to bridge this discrepancy, a frame element that is thicker than other frame elements can be inserted between two plates.
[0035] Alternatively, it is also possible to mount the standardized plates spaced from one another on a carrier plate and to fashion the regions of the carrier plate which remain free—insofar as this is required for the light-oriented job that has been raised—by, for example, either silk screening, lacquering or sand blasting so that a light passage into the corresponding regions is either impeded or prevented or light is dispersed in these regions.
[0036] The invention also makes a method available for manufacturing a plurality of lamps of a lamp system that is composed of a plurality of lamps having different light emission properties. The lamps comprise at least one hollow light guide having a cavity into which light is beamed from one or more lamps and have at least one output device for coupling light out of the hollow light guide to a light exit face, so that the light output device comprises at least one light-transmissive element, for example a plate, having a boundary surface between two media with a different refractive index that is provided with a light-refractive structure that deflects light directed in at least one plane perpendicular to the light exit face so that the light intensity distribution curve of the light emerging at the light exit face in this plane is influenced. The lamps have a support structure, particularly a housing, at or in which at least one optically effective element that influences the beam path of the light emitted by the lamp is attached or installed. The method comprises the following steps:
[0037] providing or offering a support structure for different lamps;
[0038] providing or offering a plurality of units of an optically effective component for influencing the beam path of the light emitted by the lamp, said component having dimensions that are compatible with every provided support structure, preferably with the support structure of all lamps of the system, so that the component can be installed in and/or attached to each of the provided support structures; and
[0039] attaching these components in or at the provided support structures of the various lamps.
[0040] According to this method, a standardized component is mounted at all lamps, whereby further components that differ for different lamps can be mounted in order to produce the different light-oriented properties.
[0041] The component can, in particular, be either an input reflector, a light output device, a plate with a light-refractive structure or a reflective cap wall. The support structure can be identical for a plurality of the lamps.
[0042] Further steps for manufacturing different lamp types within the system derive from the above-described lamp types that can be present within a system
[0043] The invention, in particular, also makes a method available for a modular manufacture of a lamp.
[0044] According to one aspect of the invention, a method is made available for manufacturing a lamp, particularly a recessed, add-on, floor or pendulum lamp, having at least one hollow light guide into which light is beamed from one or more lamps, and having at least one light output device for outputting light from the hollow light guide to a light exit face, whereby the light output device has at least one boundary surface between two media having different refractive indices. The boundary surface is provided with a light-refractive structure that deflects light directed perpendicular to the light exit face in at least one plane so that the light intensity distribution curve of the light emerging at the light exit face is influence in this plane, and the lamp comprises a support structure, particularly a housing, to which one or more prefabricated, optically effective component parts that influence the beam path of the light emitted by the lamp are attached, and the structure defines a specific surface for the acceptance of these optically effective component parts. The method comprises the following steps:
[0045] offering or providing one or more pre- fabricated, optically effective components having predetermined dimensions;
[0046] arranging the component or components so that the predetermined surface is completely filled or is filled accept for one or more regions whose dimensions are smaller than the dimensions of the component; and
[0047] fastening the components to the support structure in conformity with this arrangement.
[0048] In the method, the insertion of one or more spacer elements can be provided between or next to the component or the components so that the predetermined surface is completely filled by the spacer elements and the component or, respectively, the components, and the components and the spacer elements are secured to the support structure so that the predetermined surface is filled. In particular, it can also be provided that at least two of the spacer elements have different dimensions.
[0049] The invention can also provide that the light output device has a light output surface via which light is coupled out of the hollow light guide and has a predetermined dimension. The method comprises the following steps:
[0050] offering or providing one or more light-transmissive plates having a light-refractive structure producing a shielding at a base area;
[0051] arranging the plate or plates so that a predetermined area that corresponds to the light exit face is completely filled or filled except for one or more regions whose dimensions are smaller then the dimensions of the plates, whereby spacings from one another or from the edge of the predetermined surface can remain next to or between the plates; and
[0052] fastening the plates in an opening of the housing of the hollow light guide in this arrangement.
[0053] The invention can provide the insertion of one or more spacer elements between or next to the plate or the plates so that the predetermined surface is completely filled by the plate or, respectively, plates and the spacer elements, and can also provide the fastening of the plates and of the spacer elements in an opening of the housing of the hollow light guide so that these limit the cavity of the hollow light guide and, in particular, can thereby provide the connection of at least a part of the spacer elements and of the plate or, respectively, at least a part of the plates to a plate lying thereabove to form a unit.
[0054] The spacer elements can, in particular, be frame elements that hold a plurality of plates together or can also serve for supporting a single plate at the housing of the hollow waveguide or at the lamp housing.
[0055] It can also be provided that, for forming the light output device, a plurality of plates having a light-refractive structure that generates a shielding are arranged side-by-side, at least two thereof comprising the same shape and the same dimensions.
[0056] The invention is based on the surprising perception that it is possible in a significantly greater scope then hitherto possible to construct interior lamps of standardized parts when a hollow light guide is employed as a light-oriented basic unit. The reason for this is, on the one hand, that hollow light guides can be realized with a relatively slight structural height that can be unproblemmatically integrated into the housings of lamps for the greatest variety of light-oriented applications. The output of an indirect light part given a hollow light guide can be realized, for example, in that a wall, for example the roof wall, is fashioned partially light-transmissive. As a result of a corresponding shape of the cap reflector, the shape of the light intensity distribution curve can also be modified without modifying the shielding conditions. Added thereto as a further advantage is that plate-shaped, light-refracted elements are employed for defining the light intensity distribution curve at a light exit face. These elements are realized with essentially the same dimensions regardless of the desired, light-oriented function, and are therefore capable of being interchanged between different lamps. For example, a lamp for picture screen workstations can be converted into a lamp having an asymmetrical light emission characteristic by simply replacing a prism plate. Likewise, other light-oriented elements, for example input reflectors, can be easily modularly combined with a hollow light guide.
[0057] A particular aspect of the present invention is the possibility of constructing specific light-oriented devices, for example the light output device, modularly from standardized basic elements.
[0058] The inventive lamp system particularly comprises lamps, for example recessed, add-on or pendulum lamps wherein the light output device comprises at least one or more units having at least two plates or foils connected to one another. The unit or units are inserted into an opening of the housing of the hollow light guide, which opening limits the cavity of the hollow light guide.
[0059] According to one embodiment of lamps of the system, the light output device comprises a plurality of plates arranged next to one another that are respectively provided with a light-refractive structure on a base area that generates a shielding.
[0060] It can be inventively provided that the light output device of a lamp comprises a stack of at least two plates preferably having the same base area that are respectively provided with a light-refractive structure for generating a shielding. The light-refractive structure of a first plate in a first plane perpendicular to the light exit face essentially prevents the light output above a limit angle relative to the perpendicular vis-a-vis the light exit face. The light-refractive structure of a second plate either does not prevent or only prevents the light emission above a larger limit angle in the front plane, and the light-refractive structure of the second plate essentially prevents a light emission in a second plane perpendicular to the light exit face above a limit angle relative to a perpendicular vis-a-vis the light exit face. The first plate either does not prevent or only prevents the light output above a larger limit angle in the second plane. In particular, the invention can provide that the light output device comprises a plurality of the stacks that are arranged next to one another in order to form the light output face of the light output device.
[0061] The invention can provide that the light- refractive structure of the plates of a light output device comprises line-shaped, light-refractive structural elements or is composed of these elements. The elements have side walls essentially parallel to the line direction that describe an angle at the free end of the structure elements that preferably lies in a range from 90° through 130° for lamps having shielding greater than 90° and that, according to a specific embodiment of the invention, can lie in a range from 110° through 128°. The above-indicated angular ranges from 90° through 130° or, respectively, 110° through 128° are particularly preferred for plates composed of a material having a refractive index of approximately 1.49, but the ranges can also be employed given materials having a refractive index that does not differ all that much from 1.49. This applies to standard materials such as glass or polymethylmethacrylate. Fundamentally, however, the preferred angular ranges can be different for materials having a refractive index different from 1.49, and these preferred angular ranges for these refractive indices can be determined so that the same shielding angles are achieved for a predetermined limit value of the luminous intensity as in the above-specified angular range of 90° through 130° or, respectively, 110° through 128° given a refractive index of 1.49. According to the preferred embodiments, however, this angle should fundamentally be greater than 90° independently of the refractive index for lamps with shielding. Preferably, this angle is the same in all structure elements that, moreover can also all have the same cross-sectional shape and, potentially, identical dimensions as well. Other angles can be expedient for lamps without shielding, whereby angles differing from 90° are also preferred here.
[0062] The limit value of the luminous intensity for a shielding can lie at 200 cd/m 2 , 500 cd/m 2 or 1000 cd/m 2 in conformity with the prevailing standards or, respectively, proposed standards. The shielding angle in standard applications lies in the range of more than 45°, preferably in a range from 50° through 75°, and particularly in a range from 50° through 65°.
[0063] According to the preferred embodiment of the invention, the light-refractive structure elements have a constant cross-section along the line direction that, in particular, can assume the shape of a triangle. The sidewalls of the elements, however, need not be planar but can also be curved. Whereas the side walls directly adjoin one another at the free end of the structure elements according to a preferred embodiment, it can also be provided that the free end of the structure elements is flattened and the side walls are connected by a planar or curved surface. In the case of planar lateral surfaces or lateral surfaces having a planar section at the free end, the aforementioned angle is then defined by the imaginary extension of the planar side walls or, respectively, of the planar sections of the side wall. In a case of the curved side walls, the aforementioned angle can correspond to the angle of a triangle that the cross-section of the light-refractive elements optimally describes, i.e. with optimally little area deviation between the area of the triangle and the cross-sectional area of the light-refractive element. In the case of a convex side wall, i.e. a side wall curved outward, this angle would be formed by the intersecting angle of two tangents that are applied to the sidelines of the cross-section of the light-refractive element, and, in the case of a concave sidewall, i.e. an inwardly curved sidewall, this angle would be defined by two straight lines that are respectively placed between the head point and the foot point with a side line of the cross-section, i.e. a line corresponding to the sidewall in cross-section.
[0064] It can be inventively provided that a respective light-refractive structure having line-shaped structure elements is fashioned in two plates arranged above one another, whereby the lines that define the geometry of the structure of the first plate describe a non-disappearing angle with the lines that define the geometry of the structure of the second plate and preferably reside perpendicularly thereon.
[0065] The light-refractive structures can, for example, be manufactured in that a plate or foil of a standard, light-transmissive material such as glass, polyester, polystyrol, polycarbonate, PET or polymethylmethacrylate, is correspondingly processed or shaped on a surface. Alternatively, a foil that contains the light-refractive structure can also be glued onto such a plate.
[0066] It can also be provided that at least one of a plurality of plates lying above one another is held at least in sections on another plate by one or more frame elements that overlap this plate.
[0067] In order, given an entirely or partially light-transmissive frame, to prevent light that does not meet the shielding conditions from being coupled out in the region of the frame, the light output device can be either lacquered, provided with a silk screening, mirrored or sand blasted at the light exit side in the region of the frame or of the frame elements. Fundamentally, however, this region can remain entirely or partially light-transmissive, namely when the light parts with the exit angle above the shielding angle are so small that the limit value for the average luminous intensity of the entire light exit face, including the regions wherein the light-refractive structures are active, is not exceeded.
[0068] According to a preferred embodiment of the invention, the plates with the light-refractive structure generating a shielding are arranged on a carrier plate that has no particular properties influencing the light intensity distribution curve and that preferably comprises two parallel, smooth base surfaces.
[0069] In particular, it can be provided that at least two plates with a light-refractive structure generating a shielding are arranged side-by-side on a carrier plate and are connected to the carrier plate.
[0070] The invention can provide that the plates provided with a light-refractive structure generating a shielding are held on the carrier plate by at least one frame element which is connected to the carrier plate, and the frame element overlaps one or more of the plates with a light-refractive structure.
[0071] Further plates, particularly plates having a light-refractive structure generating a shielding, can be arranged on the plates lying next to one another, so that a plurality of stacks of at least two plates that preferably respectively comprise a light-refractive structure generating a shielding are arranged overall on the carrier plate and are held on the carrier plate in a suitable way, for example by a frame element or a frame.
[0072] It is provided according to a specific embodiment that at least two, preferably all structured plates arranged next to one another have the same shape and the same base area.
[0073] In particular, the base area of the plates can be quadratic.
[0074] According to this embodiment, the lamp can be standardized in that plates having a light-refractive structure are employed that have permanently prescribed dimensions. These plates can then be manufactured in greater numbers and, thus, more cost-beneficially.
[0075] Further features and advantages of the invention derive from the following, detailed description of an exemplary embodiment with reference to the attached drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0076] [0076]FIG. 1 is a schematic cross-section through a lamp of an inventive lamp system;
[0077] [0077]FIG. 2 is a schematic plan view of a carrier plate with the prism plates mounted thereon;
[0078] [0078]FIG. 3 is an enlarged cross-sectional view of the prism plates taken along the line III-III of FIG. 2;
[0079] [0079]FIG. 4 is an enlarged cross-sectional view of the prism plates taken along the line IV-IV of FIG. 2;
[0080] [0080]FIG. 5 is a partial enlarged cross-sectional view taken along the line V-V of FIG. 2;
[0081] [0081]FIG. 6 is a partial enlarged cross-sectional view taken along the line VI-VI of FIG. 2;
[0082] [0082]FIG. 7 is a bottom plan view of an embodiment of a second lamp of an inventive lamp system;
[0083] [0083]FIG. 8 is a bottom plan view of an embodiment of a third lamp of an inventive lamp system; and
[0084] [0084]FIG. 9 is a bottom plan view of an embodiment of a fourth lamp of an inventive lamp system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0085] [0085]FIGS. 1 and 7 through 9 schematically show four different lamp types that can be part of an inventive lamp system, whereby the inventive lamp systems are not limited to systems having the illustrated lamps or lamps having similar or coinciding properties.
[0086] [0086]FIG. 1 schematically shows an example of an embodiment of a lamp of an inventive lamp system. The lamp according to FIG. 1 comprises a housing, generally indicated at 1 , in which a hollow light guide 3 is arranged. The hollow light guide 3 is composed of a reflective roof wall 5 having two halves 5 a and 5 b inclined at an obtuse angle relative to one another, reflective face or end walls (not shown) at the two end faces as well as a light output device 7 that shall be described in greater detail. The face walls, the roof wall 5 and the light output device 7 together define a cavity 8 with reflective walls.
[0087] The hollow light guide 3 is respectively opened at the two narrow sides. A respective lamp 9 (only shown at one side) is arranged at these open narrow sides, and the lamp couples light into the hollow light guide 3 via an input reflector 11 .
[0088] The housing 1 is composed of an upper housing half 13 to which the roof wall 5 is secured as well as side members or ledges 15 , which overlap the hollow light guide 3 and edge portions of a bottom surface of a light output device 7 and holds the light output device to the hollow light guide 3 . A ballast device 17 is secured to the upper housing part 13 , and the ballast device 17 extends into the region above the hollow light guide 3 wherein the two roof halves 5 a and 5 b have a reduced spacing from the light output device 7 . Accordingly, the halves 5 a and 5 b define an enlarged spatial region in the housing above the hollow light guide 3 , so that a relatively slight overall structural height can be achieved, which feature is advantageous, particularly given an add-on or pendulum.
[0089] The light output device 7 is composed of a carrier plate 20 which has two pairs of quadratic prism plates 22 and 24 or, respectively, 26 and 28 that are arranged above one another. The carrier plate 20 forms the light output surface of the light output device 7 that coincides with a light exit face 29 in the case of this light. The prism plates are provided with a prism structure on a base area that generates a shielding of the light emerging via the light output device 7 and that is explained in greater detail below for the prism plates 22 and 24 .
[0090] The prism plates 22 and 24 are provided with a structure that essentially prevents a light output above a limit angle relative to the perpendicular vis-a-vis the light exit face in specific planes and thereby produces a shielding, and a lowering of the average luminous intensity of the light exit face below a limit value, for example 200 cd/m 2 , 500 cd/m 2 or 1000 cd/m 2 , as required in the applicable standards or, respectively, proposed standards for picture screen workstations.
[0091] At its side facing away from the cavity 8 , the prism plate 24 has a structure of parallel prisms 30 that have a triangular shape in a cross-section perpendicular to their longitudinal axis, as can be seen with reference to FIG. 3. FIG. 3 shows that the prisms directly adjoin one another, comprise ridges 32 a , 32 b , . . . , which ridges are collectively referenced as 32 , uniformly spaced from one another and are separated from one another by depressions 34 a , 34 b , . . . , which are collectively referenced as 34 , that are uniformly spaced from one another. The depressions 34 and the ridges 32 form straight, parallel lines at that surface of the plate 24 facing away from the cavity 8 .
[0092] The shielding can, for example, be produced by total reflection in the prisms. Light in the prisms, given incidence on the boundary surface to an optically thinner medium, for example air, is completely reflected back into the prisms when the incident angle is greater than the angle for the total reflection. Accordingly, the exit angle for the boundary surfaces of the prisms is limited. The side walls of the prisms between the ridges 32 and the depressions 34 , however, reside obliquely relative to the light exit face, so that the limitation of the light exit angle by the limit angle of the total reflection does not necessarily mean a shielding. One possible criterion for a shielding can be derived so that the exit angle with respect to a perpendicular relative to the base area of the light-refractive structure is maximally equal to the shielding angle for the beam paths in the prims up to a predetermined maximum number k (for example, k=1, 2, 3 or 4) of internal reflections in the prisms before a light exit from the structure. Other shielding mechanisms or shielding criteria can also be alternatively or additionally employed.
[0093] It has been shown that a good shielding is achieved for prisms having a cross-section in the form of an equilateral triangle when the following relationships exist between the shielding angle C and the prism angle w for a boundary surface to air.
w/2≦C (1)
w≧2 (2 arcsin(1/n)+90)/3 (2)
tan(w/2)≦(n sin(arcsin(1/n)−3 w/2)+cos(w/2))/(n cos(arcsin(1/n)−3 w/2)+sin(w/2)), (3)
[0094] whereby n is the refractive index of the plate 24 .
[0095] The prism angle w for the currently preferred embodiments with a refractive index of 1.49 lies in the range from 90° through 130°. Preferably, w is in the range from 110° through 128°.
[0096] Instead of the triangular prisms shown in FIG. 3, other prism shapes can also be employed.
[0097] The prism plate 22 (see FIG. 4), like the plate 24 , is provided with a structure of parallel, straight line prisms 36 that comprise ridges 38 a , 38 b , . . . , which are collectively referenced as 38 , and that are separated from one another by depressions 39 a , 39 b , . . . , which are collectively referenced as 39 . Just like the prisms 30 , the prisms 36 produce a shielding in the direction transversely relative to their longitudinal axis, whereby the relationships (1) through (3) can be particularly satisfied. As can be seen with reference to FIGS. 3 and 4, the longitudinal direction of the prisms 30 is perpendicular to the longitudinal direction of the prisms 36 . Together, the prism plates 22 and 24 therefore generate a shielding in planes perpendicular relative to one another that reside perpendicularly on the light exit face 29 . In this way, a shielding is produced in at least two planes. The shielding angle C can be different in these two planes. Accordingly, the prisms 30 and 36 can also exhibit a different prism angle w.
[0098] For the sake of completeness, let it be noted here that the illustrated prisms can also generate a shielding in planes between the two planes perpendicular to the respective longitudinal direction. The same can also apply to other prism shapes.
[0099] The prism plates 26 and 28 have the same structure as the prism plates 22 and 24 and are aligned in the same way relative to one another. The prisms of the plate 22 lie parallel to those of the plate 26 and those of the plate 24 lie parallel to those of the plate 28 .
[0100] The prism plates 22 and 24 or, respectively, 26 and 28 are held at the carrier plate 20 with frame elements 40 and 42 (see FIG. 2). The type of connection is shown in detail in FIGS. 5 and 6. A frame element 40 is provided at the outer edges or sides for the fastening of the prism plates. The frame element 40 comprises a central section 44 at which flanges 46 and 48 adjoin at a right angle at both ends, and these flanges 46 and 48 point in opposite directions. The flange 48 is glued on the plate 20 . The flange 46 overlaps the plates 22 and 24 (or, respectively, 26 and 28 ) and thereby holds these positively locked on the carrier plate 20 .
[0101] A U-shaped frame element 42 is provided in the inside of the light output face in the region between the pairs of plates 22 and 24 or, respectively, 26 and 28 . The U-shaped frame element 42 has two flanges 52 and 54 adjoining at a right angle at opposite sides at its open end, these flanges extending in opposite directions. The base surface 56 of the frame element 42 is glued fast to the carrier plate, whereas the flanges 52 and 54 overlap the plates 22 and 24 or, respectively, 26 and 28 . Overall, three frame elements 40 together with the central frame element 42 form a frame for the two plates 22 and 24 that holds these plates positively against the carrier plate 20 , and three further frame elements 40 together with the frame element 42 form a frame for the two prism plates 26 and 28 that holds these prism plates against the carrier plate 20 . Overall, the carrier plate 20 , the prism plates 22 through 28 as well as the frame elements 40 and 42 form a pre-fabricated unit that is introduced into the opening of the hollow light guide 3 and is held at the hollow light guide by the lateral ledges 15 . The plates and the appertaining prism structures are thereby correctly aligned relative to one another by the frames 40 and 42 and by the fixing against the carrier plate 20 .
[0102] For manufacturing the light output device 7 , the frame elements 40 and 42 are designed according to the geometry of FIG. 2 with the flange elements 46 , 52 and 54 toward the bottom, and, subsequently, the prism plates 22 and 24 or, respectively, 26 and 28 are placed onto the flanges 46 , 52 and 54 so that the frame elements 40 and 42 hold the prism plates essentially free of play. Subsequently, the carrier plate 20 is put into place and glued to the flanges 48 and the base section 56 . Note that the prism structures of the plates 22 through 28 lie in the inside of the light output device 7 . In this way, a unit, which has a smooth, easily cleaned surface on both sides, is formed and the prism structures are terminated by the frame elements 40 and 42 as well as the carrier plate 20 . Preferably, the inner region of the light output device, which has the prism structures, is tightly closed, so that dust or other contaminates cannot penetrate into the region of the prism structures. To this end, a seal (not shown) can be provided between the flanges 46 and the flanges 52 and 54 and the prism plate lying therebelow to seal the gap between the frame and the prims plates. The unit is tightly closed by a glued connection to the carrier plate 20 at the opposite side.
[0103] The light from the lamp 9 or, respectively, the input reflector 11 is partly directly incident onto the plates 22 and 26 . A part of this light passes through the plates 22 and 24 or, respectively, 26 and 28 and emerges at the light exit face 29 . Another part of the light is reflected by the plates 22 and 26 . The roof wall 5 reflects the light incident directly onto it from the lamp 9 or, respectively, the input reflector 11 as well as the light reflected back to it from the plate 22 or, respectively, 26 downward to the light output device 7 .
[0104] [0104]FIGS. 7 through 9 show further lights that can be a component part of an inventive light system. These lights have the same structure as the light shown in FIG. 1, which shall therefore not be explained again, and differ merely on the basis of the design of the light output device 7 . Identical component parts are provided with the same reference characters.
[0105] In the embodiment according to FIG. 7, a pair of prism plates 59 lying above one another (whereof only the upper plate is visible in FIG. 7) are held on a carrier plate 58 by frame elements 40 , as described above with reference to FIG. 4. This embodiment is provided for employment of relatively short fluorescent bulbs, for instance the standard 8W fluorescent bulbs.
[0106] In the exemplary embodiment according to FIG. 8, four pairs of prism plates 60 , 62 , 64 and 68 as described above with reference to FIGS. 1 through 6 are secured on a carrier plate 68 , whereby the outer edges of the prism plates are held against the carrier plate 68 by the above-described frame elements 40 and the inner edges of the prism plates are held against the carrier plate 68 by the above-described frame elements 42 . Preferably, the frame elements 40 and 42 are glued to the carrier plate 68 . Such an embodiment could, for example, be operated with two standard 21W fluorescent bulbs that are respectively arranged at an open narrow side of the hollow light guide 3 .
[0107] [0107]FIG. 9 shows an embodiment of the invention wherein the distance between the lamps 9 is increased. Four pairs of prism plates 80 , 82 , 84 and 86 that are fashioned like the above-described prism plate pairs 22 and 24 or, respectively, 26 and 28 are secured in the above-described way on the carrier plate 88 with frame elements 40 and 42 . Instead of four individual frame elements 42 , a cross-shaped frame element can also be employed whose four arms are fashioned in cross-section like the frame elements 42 and that unites the function of the four frame elements 42 in one component part. This light could, for example, be operated with two 24 W fluorescent bulbs.
[0108] The various embodiments of the light, particularly the embodiments according to FIGS. 1 and 2 and 7 through 9 , form component parts of a light system that comprises lights for differently dimensioned and, accordingly, fluorescent bulbs that have different lengths, whereby all prism plates employed in this system, i.e. the prism plates 22 and 28 and the prism plates of the pairs 52 , 60 through 66 and 80 through 86 , have the same dimensions. For various lights of the system, two, three, four or more prism plates are attached on a carrier plate and connected thereto successively in the longitudinal direction of the lamps (see FIGS. 2 and 8) and/or in a transverse direction relative to the longitudinal direction of the lamps (see FIG. 9). These prism plates are attached with the assistance of frame elements 40 and 42 , so that a composite light exit face arises.
[0109] This is advantageous for rational production with high piece numbers, since the prism plates need not be separately fabricated for each light type. A standardized plate type can be employed for each lamp or light type.
[0110] While the above-described light system was based on a fact that prism plates of the same dimensions were employed for lamps having different length or width, an inventive light system—alternatively or additionally—can also be constructed on the basis of different basic elements. For example, all lights of an inventive light system can have prism plates with the same dimensions but a respectively different light-refractive structure, so that the light-steering properties and, in particular, the shielding properties are respectively different. A light of the system is derived from a different light by the corresponding prism plate being replaced. Likewise, a system can be built with the same carrier structure or the same housing being employed and the differently utilized light-technical components such as lamps, input reflectors, prism plates, cap reflectors, etc., being different. Likewise, a further property of the inventive light system can be provided in that standardized cap reflectors or input reflectors are employed, and these have different light-oriented properties for respectively different lights. For example, one light of the light system can have a cap reflector having two inwardly inclined, planar surfaces, as shown in FIG. 1, a second light of the system can have a cap reflector of the same length and width but with one or more curved surfaces; and a third light can have a cap reflector of the same length and width that is completely flat, etc. Of course, a plurality of the aforementioned design principles can also be combined. For example, a replaceable cap reflector composed of a plurality of modules of given length that can be combined to form cap reflectors of different length can be employed together with a light output device that, as explained above, is constructed of a plurality of standardized prism plates.
[0111] Although various minor modifications maybe suggested by those versed in the art, it should be understood that we wish to embody within the scope of the patent granted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art. cm We claim: | A light system composed of a plurality of lights with each light having different light emission properties. The component parts of each of the lights, such as optically effective components that influence the beam path of the light emitted by the lamp, and end cap reflectors are of a standard dimension so that lights of different configurations can use the same elements to reduce the number of different parts required for the group of different lights of the system. | 5 |
This is a continuation of application Ser. No. 07/404,548, filed Sept. 8, 1989, now abandoned.
BACKGROUND OF THE INVENTION
The present invention is directed to a head band having a depending fabric piece detachably or permanently connected thereto and adapted to cover the neck of the wearer to protect the same from sunburn. The head band may completely or partially encircle the head of the wearer and may be used independently or in conjunction with a cap.
The use of havelocks is old and well known in the art. The most familiar use of a havelock is perhaps the well known Foreign Legion hat which has a substantially cylindrical pillbox-shaped configuration with a front visor and a depending rear covering for protecting the neck from sun or bad weather. An example of such a hat with a havelock is shown in U.S. Pat. No. 2,844,822.
While the havelock shown in U.S. Pat. No. 2,844,822 is of integral one piece construction with the hat material, the havelock could be detachably connected to the hat as shown in U.S. Pat. No. 2,897,510.
SUMMARY OF THE INVENTION
The present invention provides a new and improved sunshield for protecting the neck of the wearer wherein the sheet of fabric material constituting the sunshield may be detachably or permanently connected to a head band. The head band may be supported directly on the head or may be used in conjunction with a cap. When the head band is used in conjunction with a cap, the head band can completely encircle the cap in the vicinity of the head band of the cap, or may be a partial head band which is detachably connected to the cap.
The foregoing and other objects, features and advantages of the invention will be apparent from the following, more particular description of preferred embodiments of the invention as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first embodiment of the present invention showing a sunshield and head band as used in conjunction with a cap.
FIG. 2 is an enlarged perspective detail of the rear of the cap showing the location of a fastener for the head band.
FIG. 3 is a perspective view of the sunshield and head band of FIG. 1 without the cap.
FIG. 4 is a perspective view of the sunshield and head band of FIG. 3 as used without a cap.
FIG. 5 is a perspective view of a sunshield and head band according to a second embodiment of the present invention.
FIG. 5A is a partial detailed showing of the connecting means for the head band of FIG. 5.
FIG. 6 is a perspective view of a partial head band and sunshield according to a third embodiment in detached relation with respect to a cap.
FIG. 7 is a perspective view of a sunshield according to a fourth embodiment of the present invention in detached relation to a cap.
FIG. 8 is a perspective view of a sun shield according to a fifth embodiment in detailed relation to a head band.
DETAILED DESCRIPTION OF THE INVENTION
The sunshield as shown in FIG. 1 is comprised of a sheet of material 10 of any desired configuration. The sheet of material may be a single sheet secured to a head band 12 as illustrated or may be comprised of a plurality of individual sheets which are secured in adjacent or overlapping relationship to each other. The extent to which the sunshield depends from the head band and the circumferential extent of the sunshield relative to the head band can vary widely within the scope of the present invention. The head band 12 may be of stretchable, elastic, knitted material or any other suitable material which would readily accommodate different sized heads. The head band 12 as shown in FIG. 1 is disposed in superimposed relation with the head band of a cap 14 having a visor 16. The cap may be provided with an inverted U-shaped cut out portion 18 which is spanned by an elastic head band 20 so as to render the cap adjustable for different head sizes. A strip of VELCRO fastening material 22 is secured to the elastic band 20 and cooperates with a complementary VELCRO strip 24 secured to the inside of the head band 12 as shown in FIG. 3. The material of the sunshield flap 10 is shown in FIG. 3 as being folded about the head band 12 and secured thereto by means of stitches. The head band may be endless or have ends secured in the hem of the flap. It is also contemplated within the scope of the present invention to have the sunshield flap 10 detachably connected to the head band 12 by means of separate VELCRO fastening strips 13 and 15 as shown in FIG. 8. Thus, the sunshield flap 10 could readily be secured to conventional knitted sweatbands which are in common use. . The sunshield and head band combination as shown in FIG. 3 can be worn directly on the head of a wearer as shown in FIG. 4 without a cap as shown in FIG. 1.
In a second embodiment as shown in FIG. 5, the head band 26 may be constructed of flexible plastic material with the ends disposed in overlapping relation. The overlapping ends may be adjustably secured by a plurality of protuberances 28 and complementary apertures 30 to accommodate the head band to varying head sizes. The sunshield flap 32 may be provided with a pair of spaced apart, tubular hem portions 34 through which the head band 26 may be removably inserted. Thus, the sunshield flap 32 can readily be mounted on or removed from the head band 26 which in turn may be adjustably sized to fit different head sizes.
In the embodiment of FIG. 6, the head band 36 does not completely encircle the head of the wearer, but only extends the width of the flap 38. The partial head band 36 may be of flexible, semi-rigid plastic material having a pair of hooks 39 integrally formed thereon which are adapted to hook over the conventional head band 40 on a cap in the vicinity of an inverted U-shaped cut out portion 42 of the cap 44. The ends of the partial head band 36 extend into blind, tubular hem portions 46 on the upper edge of the sunshield flap 38. Thus, the head band and sunshield flap combination may be detachably connected to a conventional cap and the sunshield flap 38 may be detachably connected to the head band 36 to facilitate washing of the sunshield.
In the embodiment of FIG. 7, the sunshield flap 50 is not used in conjunction with a head band, but is secured directly to the rear of a cap 52 by means of two pairs of complementary VELCRO fasteners 54 and 56. The VELCRO fasteners 54 and 56 are mounted directly on the cap at opposite sides of the U-shaped opening 58 and on opposite corners of the sunshield flap 50.
The material of the head band, the flap and the cap may vary and various types of fasteners may be used in lieu of VELCRO.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention. | An elastic head band is provided with a depending neck shield to protect the wearer's neck from sunburn. The head band may be worn in conjunction with a cap or the neck shield without the head band may be detachably connected to the rear of a cap. | 8 |
This invention relates to a fusible link construction which normally is subjected to a constantly applied force that is resisted by a thermally sensitive link until such link collapses, thereupon resulting in the automatic actuation of a device such as a door closure, a fire extinguisher, or an alarm.
BACKGROUND OF THE INVENTION
A fusible link conventionally is used in those instances in which it is desired that some mechanism operate automatically, but not until there is an increase in temperature such as that resulting from a fire. Mechanisms of the kind adapted for such automatic operation include fire door closing apparatus, sprinkler operating units, alarm systems, and the like. Conventionally, a fusible link is interposed between relatively movable members which are restrained from movement by a temperature sensitive strut until such time as its temperature increases to a predetermined level, whereupon the link collapses and becomes ineffective to prevent relative movement between such members.
Numerous kinds of fusible links have been proposed heretofore, two of which are disclosed in U.S. Pat. Nos. 3,779,004 and 4,346,554. Although such fusible links are reliable, they require multiple parts, rely upon moment arms, and are relatively expensive to manufacture and assemble compared to a link according to the present invention.
SUMMARY OF THE INVENTION
A fusible link constructed in accordance with the invention comprises only four components that are simple to manufacture and easy to assemble. The parts are assembled in such manner as to avoid the necessity of having to rely upon any moment arm, thereby providing a direct relationship between the load rating of and the load applied to the link.
A preferred embodiment of a fusible link constructed in accordance with the invention has a tubular housing provided with a recess in one side thereof through which an arm of a yoke may be accommodated. The arm of the yoke is joined at its opposite ends to parallel legs that are spaced apart a distance sufficient to accommodate therebetween a portion of the tubular housing. At one end of the tubular housing is a seat for one end of a thermally sensitive strut, the opposite end of which seats upon the arm of the yoke. The yoke is maintained in assembled relation with the tubular housing and the strut by key-like guides and a retaining screw that is fitted to the tubular housing forms an anchor at one end of the link, and is adapted for attachment to a force applying member. That end of the yoke opposite the arm is adapted for attachment to another force applying member which, in conjunction with the first-mentioned force applying member, constantly applies a force on the link tending to separate the members thereof, which force normally is overcome by the strut.
The strut contains a eutectic material which, in response to a predetermined rise in its temperature, effects disintegration and collapse of the strut, thereby removing the resistance offered to the forces applied by the force applying members. The housing and yoke members of the strut thus are capable of movement relative to one another. One edge of the recess in the tubular body is formed as an inclined ledge which cams the arm of the yoke outwardly of the recess, thereby permitting separation of the housing and yoke members in response to collapse of the strut.
THE DRAWING
A preferred embodiment of the invention is disclosed in the following description and in the accompanying drawing wherein:
FIG. 1 is an elevational view illustrating the parts of the fusible link in assembled relation;
FIG. 2 is a sectional view taken on the line 2--2 of FIG. 1;
FIG. 3 is a front elevational view of the tubular body member only;
FIG. 4 is a side elevational view of the tubular body member;
FIG. 5 is a front elevational view of the yoke member; and
FIG. 6 is a side elevational view of the yoke member.
DETAILED DESCRIPTION
A fusible link formed in accordance with the preferred embodiment of the invention is designated generally by the reference character 1 and comprises a tubular body member 2, a flat body member or yoke 3, a thermally sensitive strut 4, and a retaining screw 5.
The tubular body 2 has a generally cylindrical housing having a wall 6 through which extends a bore 7 terminating at one end in a shoulder or seat 8. In communication with the bore 7 is an axial port 9, a radial port 10, and a recess 11 defined by parallel, longitudinal sides 12 and 13, a radial top edge 14, and an inclined lower ledge 15. That end of the bore remote from the seat 8 is threaded. The ports 9 and 10, as well as the recess 11, ensure communication of the bore 7 with ambient temperature.
The body or yoke 3 comprises a flat member having parallel, spaced apart legs 16 and 17 connected at corresponding ends by an arm 18 and at their opposite ends by converging limbs 19 and 20 joined to one another by an arcuate connector 21. The legs, the arm, and the limbs of the yoke 3 define an open space 22 the transverse dimension of which is greater than the diameter of the tubular housing 6. The legs 16 and 17 are provided with inwardly directed guide keys 23 which extend inwardly of the space 22, but terminate short of one another. The keys 23 may be slideably accommodated in keyways 24 formed in opposite sides of the housing 6. The arm 18 has an outwardly projecting spike 25 on its outer surface and a dimple or detent 26 in its inner surface.
The strut 4 is conventional and comprises a sealed body 27 formed of a glass material known as quartzoid, or other suitable material, and containing a eutectic liquid such as a mixture of water and glycerin which expands rapidly in response to an increase in its temperature to a predetermined level. The body 27 has at one end thereof a tapered neck 28 that terminates in a tip 29. The opposite end of the body 27 terminates in a convex nose 30.
The retaining screw 5 has a threaded stem 31 adapted for accommodation in the threaded end of the bore 7, such stem 31 terminating at one end in a dimple 32 that is nestable with the spike 25. At its opposite end the stem 31 terminates in an anchor member 33 having an opening 34 therein.
The parts of the link 1 may be assembled by fitting the body 27 of the strut 4 into the bore 7 of the housing 6 in such manner that the strut is interposed between the arm 18 and the seat 8. Thereafter, the yoke 3 may be assembled with the housing by introducing the keys 23 into the keyways 24 and rocking the member 3 in such direction as to enable the arm 18 to enter the bore 7 via the recess 11. The width of the keyways 24 and the distance between the edge 14 of the recess 11 and the nose 30 of the strut body 27 are sufficient to permit such rocking movement of the yoke 3.
When the arm 18 of the yoke 3 occupies the bore 7, the nose 30 of the strut body 27 may be fitted into the dimple 26 of the arm 18, following which the retaining screw 5 may be turned in such direction as to cause its dimple 32 to receive the spike 25 of the arm. Further rotation of the retaining screw 5 will cause the neck 28 of the strut 4 to seat firmly against the seat 8 and the nose 30 to seat firmly in the dimple 26. The strut 4 then will resist further rotation of the retaining screw 5. The force applied to the strut 4 by the retaining screw 5 may be that resulting from turning the screw until it is finger tight or, if a precise force is desired, by applying a torque wrench to the screw 5.
The assembled link then may be coupled at its opposite ends to chain or the like connectors 35 and 36 by means of which a continuous force in tension can be applied on the members 2 and 3 which normally is resisted by the strut 4. Should the ambient temperature to which the strut 4 is subjected reach a selected predetermined level between 160° F. and 500° F., for example, the liquid contained within the strut body 27 will expand suddenly resulting in disintegration and collapse of the strut, thereby removing the resistance to relative movement of the members 2 and 3 due to the force applied thereon via the connectors 35 and 36. Thus, the member 2 may move upwardly, as viewed in FIG. 2, and the member 3 may move downwardly, as viewed in FIG. 2. When the members 2 and 3 have moved a distance sufficient that the arm 18 engages the ledge 15, the arm will be cammed outwardly of the bore 7 through the recess 11, thereby resulting in complete separation of the members 2 and 3.
Of particular significance is the fact that the strut 4 occupies a position directly i line with the force exerted on the members 2 and 3 tending to separate them. As a consequence, no moment arms are involved in calculating the force to which the strut 4 may be subjected, nor does separation of the assembled parts of the link depend upon anything other than collapse of the strut 4. Consequently, the rating of the fusible link can be determined with great precision.
Since the link construction does not rely upon moment arms, springs, or the like, it ca be of compact size, thereby enabling it to be utilized in smaller areas than otherwise would be the case.
The disclosed embodiment is representative of the presently preferred form of the invention, but is intended to be illustrative rather than definitive thereof. The invention is defined in the claims. | A fusible link has a tubular housing having a recess in one side thereof in communication with a bore at one end of which one end of a thermally sensitive strut is seated. A yoke has at one end thereof an arm against which the opposite end of the strut seats. The strut resists relative movement of the housing and the yoke until such time as the strut collapses whereupon the arm is cammed out of the recess enabling separation of the housing and the yoke. | 5 |
[0001] This application is a national phase application of PCT/KR2006/002872, and claims priority from Korean application (KR) 20-2005-0022608 (Aug. 2, 2005) for inventor KIM, Ki Ryong.
TECHNICAL FIELD
[0002] The present invention relates to a road traffic-control signboard assembly, and more particularly, to a road traffic-control signboard assembly having an automatic returns function.
BACKGROUND ART
[0003] Road traffic-control signboards are essential elements in running of vehicles. Since road traffic-control signboards should be optimally recognized at drivers' visual fields, they are usually fixed at right angle to vertical supports which are built vertically at the margin of roads. For example, a conventional road traffic-control signboard assembly will be described below with reference to part of FIG. 1 .
[0004] In the case of the conventional road traffic-control signboard assembly, a road traffic-control signboard 40 is simply fixed to the road traffic-control signboard stay bar 1 which is extended again over the road, using a U-bolt and nut. Therefore, assemblers' manpower can be reduced but the durability thereof is very poor. The following problems are caused. That is, as stated above, the conventional road traffic-control signboard assembly assembles the road traffic-control signboard 40 with the traffic signboard stay bar 1 using the U-bolt and nut. Thus, if strong force is applied to the conventional road traffic-control signboard assembly, because typhoon blows, an initial position of the road traffic-control signboard 40 is changed to thus make the front surface of the road traffic-control signboard 40 turn up to the sky or down to the road, or make it suspended at a slope. As a result, the road traffic-control signboard 40 loses its function and causes a failure in safety running of vehicles.
[0005] In the meantime, if impact is applied to the conventional road traffic-control signboard assembly, due to the excessively loaded freight in freight vehicles or the top portion of special-purpose motor vehicles such as cranes or heavy equipment, the obverse of the road traffic-control signboard 40 is slanted heading toward the road or is damaged. Finally, the same problems as those described above are caused. Hereupon, local government road facilities that receive accident or damage reports ride bucket vehicles and go to sites immediately, in order to straighten the road traffic-control signboard whose initial position has been changed again or replace it by a new one. For this reason, roads are blocked to thus delay a smooth road condition and cause a big economical loss and damage nationalistically. On the other hand, when typhoon blows or after typhoon passes a lot of road traffic-control signboards are out of position over the downtown whole area. In this case, big problems such as confusion, discomfort, and traffic jams are caused.
[0006] Moreover, repair works of long hours cause various kinds of big problems. Hereupon, to solve the above-described problems, this inventor filed a Utility-model application No. 20-2003-0040773 on Dec. 26, 2003 with the Korean Intellectual Property Office entitled “Horizontal support structure for making traffic-control signboards rotate” which has been registered as a Utility-model registration No. 20-0349900-0000 on Apr. 29, 2004. By the way, the above-described registered conventional art greatly changes the structure of the existing road traffic-control signboard stay bar 1 . In principle, the existing road traffic-control signboard stay bar 1 does not cause any problem but is complicated in the structural viewpoint since a coil spring should be is mounted so as to be concentric with the road traffic-control signboard stay bar 1 . As a result, in the case of the conventional art, it is not so easy to manufacture the road traffic-control signboard 40 and assemble it in the road traffic-control signboard stay bar 1 to thus cause the manufacturing cost to greatly rise up and the maintenance to be difficult and to additionally cause an unsafe problem since the weight of the road traffic-control signboard assembly is heavy.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0007] To solve the above problems, it is an object of the present invention to provide a road traffic-control signboard assembly having a generally advanced automatic return function using structure of an existing road traffic-control signboard stay bar 1 as it is, which is preeminently improved in view of the function, economy, assembly, maintenance, weight, etc., in comparison with those of the conventional art. To accomplish the above object of the present invention, according to an aspect of the present invention, there is provided a road traffic-control signboard assembly comprising: a tubular elastic body having an insertion groove so as to be inserted into a road traffic-control signboard stay bar which is connected with a vertical support at right angle and a hole into which a rotation preventing screw can be inserted at right angle; a semicircular upper clamp which is assembled to enclose the tubular elastic body at the upper portion of the tubular elastic body, including a tightener having bolt holes through which a respective bolt is penetratively fixed for fixing a below-described lower clamp, in which the tightener is extended from the semicircular upper clamp, a hole into which a rotation preventive screw can be inserted at right angle, and a hasp which can hang a below-described tension spring on the upper portion of the semicircular upper clamp; a flat lower clamp which is hinged with the upper clamp, having bolt holes through which a respective bolt is penetratively fixed for fixing the upper clamp; a support plate which is assembled in a hinged manner with the lower clamp and the upper clamp, to support a road traffic-control signboard; a hinge pin which assembles the upper clamp, the lower clamp and the support plate all in a hinged manner; a reinforcement plate at the upper portion which a hanger for hanging the tension spring, in front of which the road traffic-control signboard is fixed, and with which the support plate is assembled with bolts and nuts; a tension spring which is assembled between the hasp of the upper clamp and the hanger of the reinforcement plate, which supports the road traffic-control signboard so as to return vertically even if the road traffic-control signboard moves; and bolts and nuts which rigidly tighten the upper clamp and the lower clamp. Preferably, a plate-shaped or rod-shaped stopper is additionally fixed on the upper portion of the upper clamp, so that the erect road traffic-control signboard is not inclined toward the upper clamp Preferably, the material of the tubular elastic body is selected among rubber, sponge, and urethane.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The above and other objects and advantages of the present invention will become more apparent by describing the preferred embodiments thereof in detail with reference to the accompanying drawings in which:
[0009] FIG. 1 is a perspective view showing the whole structure of a road traffic-control signboard assembly according to the present invention; and
[0010] FIG. 2 is a sectional view showing a-state of use of the road traffic-control signboard assembly according to the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0011] Herein below, a road traffic-control signboard assembly according to a preferred embodiment of the present invention will be described. The same reference numeral presented in the drawings show the same element.
[0012] First, the road traffic-control signboard assembly according to the present invention does not change structure of an existing road traffic-control signboard stay bar 1 but uses it as it is. In this point of view, the present invention differs greatly from the conventional art. The present invention has many inventive characteristics in which its structure is very simpler and its durability is more excellent than those of the conventional art.
[0013] That is, referring to FIGS. 1 and 2 in the present invention, a tubular elastic body 30 made of rubber, sponge, or urethane can be simply inserted into a proper position of a road traffic-control signboard stay bar 1 (hereinafter, referred to as a stay bar 1 ). As shown in FIGS. 1 and 2 , an insertion groove 31 that can be inserted into the outer surface of the stay bar 1 . The lower portion of the tubular elastic body 30 is opened and thus the insertion groove 31 can be extended by hands seizing the tubular elastic body 30 . Then, the tubular elastic body 30 can be simply inserted into the stay bar 1 . Finally, the tubular elastic body 30 is closely fixed to the stay bar 1 as shown in FIG. 2 . In the meantime, the tubular elastic body 30 is preferably fabricated in various forms in size, according to change in diameter of the stay bar 1 , but since the tubular elastic body 30 has an elasticity naturally, there is no reason to produce the tubular elastic body 30 in various sizes certainly because there is no problem to use it even if diameter of the stay bar 1 is a little big or small. Further, since the standard and diameter of the stay bar 1 are substantially the same, only one basic type of the tubular elastic body 30 can be used without causing any problems.
[0014] As described above, after the tubular elastic body 30 is inserted into the stay bar 1 , a hole is formed on the stay bar 11 through a hole 32 using a hand drill. The diameter of the hole does not cause any hindrance in intensity of the stay bar 1 . In this case, if the end portion of a rotation preventive screw 16 may be inserted into the hole, the diameter of the hole can be acceptable. Here, the tubular elastic body 30 can be assembled with the stay bar 1 after a hole has been formed on the stay bar 1 .
[0015] Next, after a semicircle upper clamp 10 is positioned at the upper portion of the tubular elastic body 30 , the rotation preventive screw 16 is assembled through the hole 32 of the tubular elastic body 30 and a hole 13 of the upper clamp 10 . Accordingly, as shown in FIG. 2 , the tubular elastic body 30 and the upper clamp 10 can be kept in their positions on the stay bar 1 .
[0016] Then, a flat lower clamp 20 which is assembled with the upper clamp 10 by a hinge pin 15 in a hinged manner, is made to contact the bottom of the stay bar 1 and to be fixed to the stay bar 1 using bolts 50 and nuts 51 , as shown in FIG. 2 .
[0017] Then, a support plate 70 is assembled in a hinged way with the upper clamp 10 and the lower clamp 20 by the hinge pin 15 . Then, a reinforcement plate 60 to which a road traffic-control signboard 40 is fixed, is located in front of the support plate 60 , and is assembled by bolts 41 and nuts 42 . That is, the support plate 70 , the reinforcement plate 60 and the road traffic-control signboard 40 are integrally formed.
[0018] As shown in FIGS. 1 and 2 , a tension spring 80 is hung between a hasp 14 of the upper clamp 10 and a hanger 61 of the reinforcement plate 60 , and assembled. As shown in FIG. 2 , a plate-shaped or rod-shaped stopper 90 is additionally fixed on the upper portion of the upper clamp 10 , so that the erect road traffic-control signboard 40 is not inclined toward the upper clamp 10 .
[0019] As described above, the rotation preventive screw 16 can be replaced by an ordinary pin, bolt, or annular rod. Here, when the tubular elastic body 30 and the upper clamp 10 are assembled with the stay bar 1 after the annular rod is soldered and fixed to the stay bar 1 beforehand, the annular rod can pass through and protrude from the respective holes 32 and 13 . However, in this case, it is naturally expected that it will be difficult to work. Also, the tubular elastic body 30 of the present invention is cut at its lower portion thereof, and thus the insertion groove 31 is opened. Accordingly, the lower clamp 20 contacts justly the bottom of the stay bar 1 , and thus the road traffic-control signboard 40 can be turned by as a big angle as an arrow trajectory of FIG. 2 . As a result, in the case that impact due to collision of a freight vehicle is applied to the lower portion of the road traffic-control signboard 40 , the road traffic-control signboard 40 is smoothly escaped from the impact lest the central portion of the road traffic-control signboard 40 should not be damaged. As being the case, a perfectly pipe-shaped tubular elastic body can be used. In the meantime, as described above, any commercial changes belong to the technical scope of the present invention.
[0020] It is natural that two sets of road traffic-control signboard assemblies according to the present invention be used for one road traffic-control signboard. If the road traffic-control signboard becomes large in size, it is natural that several road traffic-control signboard assemblies be assembled with one stay bar in use.
[0021] As described above, the road traffic-control signboard assembly according to the present invention is used in the state of FIG. 2 . Even if wind force or other impact is applied in front of the road traffic-control signboard 40 in the FIG. 2 state, the road traffic-control signboard 40 is pushed to the left-side direction of the arrow and is turned over within various angle ranges. Thereafter, if the wind force that is, birr or other impact disappeared, the road traffic-control signboard 40 returns to the original position by the pulling force of the tension spring 80 . Here, a reason why the road traffic-control signboard 40 has been pushed backward by the birr or impact which has been applied to the road traffic-control signboard 40 is because the stopper 90 is fixed to the upper clamp 10 , and thus the upper portion of the road traffic-control signboard 40 is not pushed backward based on the hinge pin 15 .
[0022] In the meantime, even in the case that strong wind blows from the left side of the road traffic-control signboard 40 to the right side thereof, in the FIG. 2 state, the road traffic-control signboard 40 is not turned to the left side of the road traffic-control signboard 40 but is turned only to the right side thereof. This is also because the road traffic-control signboard 40 cannot be turned toward the upper clamp 10 by the stopper 90 . Here, a coil spring is assembled with the hinge pin 1 , to thus keep the road traffic-control signboard 40 in its position. However, it is not always necessary to assemble the coil spring with the hinge pin 1 .
[0023] As described above, the present invention provides a road traffic-control signboard assembly having an automatic return function even if impact is applied to a road traffic-control signboard. The conventional art changes the structure of the stay bar 1 , but the present invention does not change the existing stay bar 1 in use. This feature of using the existing stay bar without changing the structure of the stay bar is inventive in itself. Further, the road traffic-control signboard assembly can be simply assembled with and disassembled from the stay bar 1 , and the structure of the road traffic-control signboard assembly is very simple. Accordingly, it is easy to fabricate the road traffic-control signboard assembly. Moreover, the present invention is more excellent in its maintenance, more inexpensive in its manufacturing unit cost, and lighter in its weight to thus enable a very easy installation and maintenance work, than those of the conventional art. As a result, the present invention has an economic efficiency having preeminently improved characteristics.
[0024] Further, a semi-permanent use is possible since the present invention has an excellent durability from the structural characteristic and the frequent breakdown has hardly occurred. In particular, the tubular elastic body 30 does not need to be fabricated according to diameter of the stay bar 1 , even if the diameter of the stay bar 1 alters a little, and the road traffic-control signboard assembly according to the present invention can be flexibly used, to thereby provide an effect of doing a big contribution in enhancing the whole economic efficiency, convenience, workability.
[0025] As described above, the present invention has been described with respect to particularly preferred embodiments. However, the present invention is not limited to the above embodiments, and it is possible for one who has an ordinary skill in the art to make various modifications and variations, without departing off the spirit of the present invention. Thus, the protective scope of the present invention is not defined within the detailed description thereof but is defined by the claims to be described later and the technical spirit of the present invention.
INDUSTRIAL APPLICABILITY
[0026] As described above, the present invention provides a road traffic-control signboard assembly which can be used for a traffic-control signboard. | Provided is a road traffic-control signboard assembly with which a road traffic-control signboard can be assembled while being linked with a vertical support at right angle. The road traffic-control signboard assembly is fitted with and fixed to a road traffic-control signboard stay bar and has a structure of being returned to an original position even if impact by typhoon or collision of vehicles is applied to the road traffic-control signboard. Thus, the road traffic-control signboard assembly prevents a phenomenon that an initial fixed position of the road traffic-control signboard is changed because of impact by typhoon or collision of vehicles which is applied to the road traffic-control signboard, to thereby lose the function of the road traffic-control signboard. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to brake drums and, in particular, to improved finished and balanced brake drums and a method of finishing and balancing such brake drums.
Most brake drums for trucks and similar heavy duty vehicles are comprised of a cast iron brake drum that is subsequently machined to near final tolerances. Typically, the machined brake drum has a slight imbalance that needs to be corrected. Accordingly, the brake drum is subjected to a balancing operation after machining. Such balancing can comprise welding correcting weights to an outer surface of the drum or removing part of the brake drum.
In particular, brake drums that have an integral raised squealer band extending from near an open end of the brake drum can be balanced by removing a portion of the squealer band. Such balancing by removing a portion of the squealer band to a constant or substantially constant depth is shown in U.S. Pat. No. 5,483,855. Another method of balancing is shown in U.S. Pat. No. 4,986,149, which discloses the removing of a crescent or wedge of material from the integral squealer band. It is desirable to provide a machined and balanced brake drum, and a method for machining and balancing such a brake drum.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved machined and balanced brake drum.
It is another object of the present invention to provide an improved method of machining and balancing a brake drum.
It is another object of the present invention to provide an improved method of machining and balancing a brake drum by machining the inner and outer radial surfaces of the brake drum. It is another object of the present invention to provide an improved method of machining and balancing a brake drum by machining the inner and outer surfaces of the hub end of the brake drum.
The improved method for balancing a brake drum in accordance with the present invention utilizes a cutting or milling machine or a lathe to machine the inner and outer radial surfaces of the brake drum. The inner and outer surfaces of the hub end of the brake drum can also be machined. This machining is accomplished in a single operation while the brake drum is held in a chuck assembly. The chuck assembly holds the brake drum at selected points around the outer radial edge of the open end of the brake drum. Such chuck assembly is designed to accurately hold the brake drum during machining to avoid eccentricity in the brake drum as it is rotated in the chuck assembly and exposed in the outer heads. Further, the brake drum is held in the chuck assembly in a manner that allows almost all of the outer radial surface of the brake drum to be machined. The result of the machining is to produce a brake drum that is balanced radially about the central radial axis of the brake drum.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a brake drum in accordance with the present invention;
FIG. 2 is an end view of the hub end of a brake drum in accordance with the present invention;
FIG. 3 is a perspective view of the open end of a brake drum in accordance with the present invention;
FIG. 4 is an end view of the open end of a brake drum in accordance with the present invention;
FIG. 5 is a perspective view of a brake drum held in a chuck assembly in accordance with the present invention;
FIG. 6 is a partial detailed side view of a brake drum held in a chuck assembly in accordance with the present invention;
FIG. 7 is a perspective view in partial cross section of a brake drum held in a chuck assembly with cutting heads also shown.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1-4 of the drawings, a brake drum in accordance with an embodiment of the present invention is shown generally at 10 . It is seen that brake drum 10 is a generally cylindrical structure, having a circular open end 12 and a generally cylindrical braking section 14 extending from open end 12 to hub end 16 . Hub end 16 is seen to comprise a generally flat outer surface 21 and inner surface 23 that terminates by forming circular hub opening 20 . A plurality of wheel lug openings 22 are spaced around outer surface 21 of hub end 16 .
Transition section 18 is seen to extend from braking section 14 to outer surface 21 of hub end 16 . Braking section 14 itself is a generally cylindrical section extending at a nearly normal relation to open end 12 . However, it is also understood that a preferred embodiment of the present invention could have the outer surface 26 of braking section 14 extending at a slightly less than normal angle to open end 12 .
It should be understood that brake drum 10 is typically made of cast iron in a foundry operation. Accordingly, finishing machining operations are necessary. Such machining would include the finishing of an inner surface 25 of braking section 14 to assure a nearly perfect inner cylindrical surface. Such surfaces are necessary to accommodate the brake pads from the braking structure that brake drum 10 would surround.
Referring to FIGS. 5 and 6 , unfinished brake drum 31 is shown to be a generally cylindrical structure. Brake drum 31 is usually made of iron in a foundry casting operation. Accordingly, outer facing surface 41 of hub end 42 , and outer radial surface 44 of brake drum 31 are shown to have an unfinished, as cast surface. Transition area 46 between hub end 42 and outer radial surface 44 is also shown to have an unfinished, as cast surface. Open end 37 of brake drum 31 faces downwardly.
It is understood that an inner facing surface (not shown) of hub end 42 also has an unfinished, as cast surface. Further, an inner radial surface (not shown) of brake drum 31 also has an unfinished, as cast surface.
Chuck assembly 30 is seen to comprise a cylindrical base section 33 . A plurality, usually four, of set up posts 32 are radially adjustably positioned in set-up post supports 52 which are themselves affixed to base section 33 . Set up posts 32 assist in the radically centered positioning of brake drum 31 on base section 33 . This assures that brake drum 31 is radially centered for concentric machining.
A plurality, usually four, of jaw clamps 34 are providing to grasp and hold brake drum 31 on base section 33 . Each jaw clamp 34 itself is held in a jaw clamp support 54 which is affixed to base section 33 . Such jaw clamp 34 is seen to be able to rotate through an arc in order to contact and hold brake drum 31 on base section 33 . Note that the contact between jaw clamp 34 and brake drum 31 is at preselected locations about radial edge 35 of an open end 37 of brake drum 31 . It is seen that the preselected contact locations are rather inobtrusive and leave almost all of the outer radial surface 44 of brake drum 31 open to machining by a cutting head.
Referring now to FIG. 7 , brake drum 31 is seen to also include inner facing surface 43 of hub end 42 , inner radial surface 45 and inner transition surface 47 between inner facing surface 43 of hub end 42 and inner radial surface 45 . Lug openings 57 are also shown in hub end 42 .
Outer hub cutting head holder 62 is seen to support cutting head arm 64 and cutting head edge 66 . It can be seen that as brake drum 31 is rotated about its radial center axis 61 while held in chuck assembly 30 , outer hub cutting head holder 62 can be programmed to have cutting head edge 66 contact and machine the entire outer facing surface 41 of hub end 42 .
Inner hub cutting head holder 72 is seen to support cutting head arm 74 and cutting head edge 76 . It can be seen that as brake drum 31 is rotated about its radial center axis 61 while held in chuck assembly 30 , inner hub cutting head holder 72 can be programmed to have inner hub cutting head edge 76 contact and machine the entire inner facing surface 43 of hub end 42 .
Outer radial cutting head holder 82 is seen to support cutting head arm 84 and cutting head edge 86 . It can be seen that as brake drum 31 is rotated about its radial center axis 61 while held in chuck assembly 30 , outer radial cutting head edge 86 contact and machine virtually the entire outer radial surface 44 and outer transition section surface 46 of brake drum 31 . Only the small area from open end 37 to the bottom 87 of the outer radial surface 44 is not machined in this operation due to the need for jaw clamp 34 to contact brake drum 31 at preselected locations 35 .
Inner radial surface cutting head holder 92 is seen to support cutting head arm 94 and cutting head edge 96 . It can be seen that as brake drum 31 is rotated about its radial center axis 61 while held in chuck assembly 30 , inner radial cutting head holder 92 can be programmed to have inner radial cutting edge 96 contact and machine the entire inner radial surface 45 and inner transition surface 47 .
Accordingly, it is seen how brake drum 31 is machined and balanced in a single operation while held in chuck assembly 30 . | An improved brake drum and method for machining and balancing a brake drum are provided. The inner facing surface and the outer facing surface of the brake drum are machined. The inner and outer faces of the hub end of the brake drum are also machined. The machining is accomplished in a single operation that results in a radially balanced brake drum. | 8 |
RELATED APPLICATIONS
This application is a continuation of U.S. non-provisional application Ser. No. 11/845,054 filed Aug. 25, 2007, now U.S. Pat. No. 7,825,745 issued on Nov. 2, 2010, entitled Variable Bandwidth Tunable Silicon Duplexer. This application also claims priority from U.S. provisional application No. 60/825,387 filed Sep. 12, 2006 entitled “Variable bandwidth tunable silicon duplexer”, incorporated herein by reference.
BACKGROUND
1. Field of Invention
This invention relates to tunable duplexers.
2. Prior Art
A duplexer is a device that isolates a receiver signal from a transmitter signal while permitting a receiver and transmitter to share a common antenna. The duplexer must be capable of handling the transmitter power and be able to provide sufficient isolation to prevent receiver desensitization due to coupling of the transmitter signal into the receiver. When the transmit and receive frequencies are different, filters may be used to reduce the transmit signal levels to an acceptable low level at the receiver input.
Nontunable duplexers used in wide bandwidth systems such as CDMA systems use a well-known method of creating the wide pass band bandpass filters by cascading resonant sections coupled to additional sections. The more sections, the wider the pass band bandwidth. For example, for a CDMA system operating in the AMPSs band, the Tx frequency band is 824 to 849 MHz and the Rx frequency band is 869 to 894 MHz. Fixed nontunable duplexers must be designed to pass all channels in the band. This would require a nontunable filter with a pass band bandwidth of greater than 25 MHz to compensate for process and temperature variations. Many cascaded sections are also needed to achieve this bandwidth and steepness in the transition bands.
In the past, duplexers were a fixed design with the frequency bands of the transmit and receive bands predetermined. A tunable duplexer can simplify the design because of the ability to tune to the desired narrowband channel. The need for tunable duplexers existed and the following references reflect the current state of tunable duplexers and tunable filters.
U.S. Pat. No. 6,990,327 issued to Zheng et al entitled “Wideband Monolithic Tunable High-Q Notch Filter for Image Rejection in RF Application”, incorporated herein by reference, describes a tunable notch filter which is contained on a single integrated chip.
U.S. Pat. No. 6,407,649 issued to Tikka et al entitled “Monolithic FBAR Duplexer and Method of Making the Same”, incorporated herein by reference, describes a monolithic bulk acoustic wave (BAW) duplexer. A patterned piezoelectric material is used as the piexolayer for each of the resonators of the duplexer.
U.S. Pat. No. 6,816,714 issued to Toncich, entitled “Antenna Interface Unit”, incorporated herein by reference, describes a ferro-electric tunable duplexer.
U.S. Patent Application Publication 2003/0199286, inventor D du Toit, entitled “Smart Radio Incorporating Parascan Varactors Embodied Within an Intelligent Adaptive RF Front End”, incorporated herein by reference, describes a radio with an RF front end containing at least one tunable duplexer. The radio incorporates Parascan® electrically controlled dielectric varactors embedded within the RF front end. Parascan® is a trademarked tunable dielectric material developed by Paratek Microwave, Inc. The RF front end described in the publication contains a tunable duplexer and two tunable filters.
An article, entitled “A Novel Electronically Tunable Active Duplexer for Wireless Transceiver Applications”, by B. Sundaram and R. Shastry, published June 2006 in Vol. 54, No. 6 of IEEE Transactions on Microwave Theory and Techniques, describes a 4-port duplexer circuit that uses varactors to enable electronic tuning of the frequency at which isolation is desired.
An article, entitled “Adaptive Duplexer Implemented Using Single-Path and Multipath Feedforward Techniques with BST Phase Shifters”, by T. O'Sullivan, R. York, B. Noren, and P. Asbeck, published January 2005 in Vol. 53, No. 1 of IEEE Transactions on Microwave Theory and Techniques, describes a technique to enhance the isolation of a surface acoustic wave duplexer, which reduces the noise levels in the receive band of the system. Feedforward techniques are used to create an adaptive null in the receive band.
An article, entitled “A Varactor Tuned RF Filter”, by A. Brown and G. Rebeiz, published Oct. 29, 1999 as a submission for review as a short paper to the IEEE Transactions on MTT, describes an electrically tunable filter at 1 GHz. The resonators used in the tunable filter are stripline interdigital fingers with varactor diodes at the ends.
U.S. Patent Application Publication 2005/0148312, inventors Toncich et al, entitled “Bandpass Filter with Tunable Resonator”, incorporated herein by reference, describes a tunable bandpass filter comprising of ferroelectric tunable tank circuits.
SUMMARY OF INVENTION
The present invention is a duplexer circuit that can be used in applications requiring a single antenna port and communicate in full or half duplex mode. Examples include AMPS, GSM, CDMA and PCS cellular phones.
The duplexer circuit of an embodiment of this invention is tunable and can be implemented on a single silicon chip. The duplexer circuit contains tunable bandpass filters which are tuned electronically by varying the capacitance of tank circuits using on-chip or off-chip varactors.
The duplexer contains two tunable bandpass filters, one for received signals and one for transmitted signals, a combining network, and a calibration circuit for setting the values of the tunable elements of the filters. The calibration circuit can be implemented using a state machine.
To achieve the required channel selectivity and the required filter performance, the center frequency, the pass band and the stop band are tunable. The pass band frequency, width, and insertion loss, and the stop band frequency, attenuation, and width, are determined by system requirements.
The ability to tune the bandwidth of the pass band of the filter to a desired narrower bandwidth channel reduces the number of resonant sections required. With the frequency tunable duplexer of the present invention, the bandpass filter can be tuned to one narrow band channel, for example 5 MHz, requiring less resonant sections, fewer components and lower cost, while achieving better signal processing performance.
The duplexer can be made with low cost lower Q inductors. The tunable filter enables positioning of the transmission zeros, herein referred to as stop band zeros or stop band nulls, in the precise location to meet stop band rejection requirements. This ability in conjunction with being able to use narrow bandwidths in the pass band allow for the use of lower Q inductors to meet the steep pass band to stop band transitions necessary. A high attenuation at a nearby frequency relative to the pass band edge can be achieved.
Another advantage of the tunable duplexer is the ability to position stop band zeros such that the nulls created occur at frequencies of known narrowband interfering signals.
High linearity is achieved by using on-chip transformers to step the signal voltages down for signal processing, then stepping up the voltage at the interface ports. Distortion is proportional to the voltage across the varactors, therefore, with a lower voltage across the diodes, the distortion is lower and linearity is improved. Linearity is additionally improved by using “back-to-back” or “totem pole” stacked varactor diodes.
Both the transmit and receive bandpass filters (BPF) are tuned simultaneously to maintain acceptable input return loss, and acceptable pass band and stop band performance. The tuning is performed by the calibration circuit, which provides tuning voltages to the varactors.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the block diagram of the tunable duplexer of the present invention.
FIG. 2 shows a filter response of the present invention where the peak frequency and the null frequency are independently tuned.
FIG. 3 shows the schematic of the tunable duplexer of the present invention.
FIG. 4 shows an example of a schematic of the tunable duplexer of the present invention with varactor capacitance values and inductor values.
FIG. 5 shows the response of the filters using the varactor capacitance values and inductor values given in FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of the tunable duplexer 100 comprising of two varactor-tuned bandpass filters (BPFs), receiver bandpass filter 110 and transmitter bandpass filter 115 , calibration circuit 120 , and a combining network 130 . Duplexed transmitted and received signals couple to TX/RX antenna 140 . The tunable duplexer is fabricated substantially on a single integrated circuit chip.
The transmitter signal at the input of the BPF 115 is stepped down in voltage by on-chip transformers. This improves the linear dynamic range of the BPF. Similarly, the receive signal at the input of the BPF 110 can be stepped down prior to filtering and subsequently stepped up after filtering. The combining network 130 can be simply a node that connects the antenna to the output of the transmitter bandpass filter 115 and the input of the receiver bandpass filter 110 . Due to the frequency dependent input and output characteristics of the bandpass filters 110 and 115 , the out-of-band signal energy is reflected and the in-band energy is passed in a low loss or lossless connection at the combining node. The step-up and step-down ratios in the transmit and receive paths can be different ratios.
The filter 110 and 115 are comprised of cascaded image-parameter filter sections. Each section can be designed using well-known filter design techniques and circuit simulation tools, for example, Agilent's Advanced Design System (ADS). The filters 110 and 115 are combined with the combining network to form a duplexer. The center frequency, the pass band and the stop band are each tunable in order to achieve the desired selectivity, pass band and stop band performance. The tuning control is determined by the calibration circuit 120 .
Calibration circuit 120 controls the tuning of the varactors used in the bandpass filters 110 and 115 . The calibration circuit 120 tunes each of the filters 110 and 115 by controlling the voltage to the varactors of filters 110 and 115 . The filters 110 and 115 have tunable center frequencies and tunable pass band and stop band bandwidths. Several independent tuning voltages may be required and used to tune the various parameters of the filters.
FIG. 2 shows a response of one of the bandpass filters 110 or 115 where f PEAK 202 and fnull 1 to fnull N 204 can be independently tuned. The resonant peak of the filters with a nearby null provides a steep transition from the passband to the stop band. The stop band nulls can be tuned to narrowband interfering, or jammer, frequencies.
FIG. 3 shows the schematic of an embodiment of the present invention, duplexer 300 . Distortion is proportional to the voltage across the varactors; therefore, if the voltage is lower across the varactors, distortion is lower and linearity is improved. In this embodiment of the present invention, a lower voltage is achieved across the varactors by using step-down transformers. Transformer 310 steps down the transmit signal. Transformer 302 steps down the received input signal and steps up the transmitted output signal, preferably with a ratio in the range of 1 to 10, or higher or lower ratios. The ratio is dependent on the center frequency and insertion loss requirements. The combining network may be a node as shown as node 314 that connects the antenna transformer to the transmit and receive filters. Filter block 306 shows the circuitry of one section of the Tx bandpass filter. The duplexer 300 may contain one or more instances of filter block 306 . Filter block 308 shows the circuitry of one section of the Rx bandpass filter. The number of filter blocks 306 and 308 needed is dependent on the required bandwidth and loss for the system. The inductors 315 and 316 in filter blocks 306 and 308 may be on-chip or off-chip. Transformers 310 and 311 may be on-chip transformers that step down the transmitter power amplifier signal and step up the signal coupled to the receiver.
Transformers 302 , 310 and 311 also function to transform impedance where the impedance of the filters can be higher or lower than the impedance of the antenna, transmitter circuit, and receiver circuit. For the ratios shown, the impedance of the filters would be lower by a factor of the square of N. The ratio of each transformer does not need to be the same.
The calibration state machine 317 supplies the voltages to the voltage controlled varactors of filter blocks 306 and 308 . The calibration state machine 317 produces the varactor control voltages for determining the center frequencies of the Tx and Rx bandpass filters and the voltages for determining the bandwidth and stop band frequencies for each filter. In one embodiment, the varactor control voltages are produced by digital-to-analog (D/A) converters driven by the calibration state machine 317 . The voltages may also be produced by D/A converters driven by a microprocessor.
To improve linearity, the varactors of filter sections 306 and 308 can be high voltage varactors. The high voltage varactors can be well-to-substrate junctions or can be fabricated with either existing process steps present on a standard low-cost IC process or with the addition of one or more process steps. An example fabrication technique to form a varactor is using the collector-base junction of a bipolar transistor by appropriately adjusting the implant doses to create a large capacitance tuning range across a high voltage range.
An alternative to achieving improved linearity without the use of high voltage varactors is to switch in multiple fixed value capacitors in parallel with the varactors in the filter. Since a larger proportion of the total capacitance now consists of linear capacitance, the linearity improves and the varactor may no longer need to be of a high-voltage type.
Tuning can be open loop with the voltages driven from a table of predetermined or premeasured values. The predetermined voltage values can be determined during filter synthesis. A set of varactor control voltages are generated for each desired tuning frequency of the duplexer. Additionally, temperature coefficients may be predetermined and added to a table to account for temperature variations. Utilizing temperature monitoring, the predetermined or premeasured voltage values can be adjusted by the temperature coefficients stored in the table.
Alternatively, tuning can be performed using an injected test tone to measure critical filter frequencies, such as the center frequency, bandwidth, and stop band nulls. The injected signal can be swept across the desired operating frequency range to verify the position of critical operating frequencies and provide information for making adjustments to tuning voltages. Open loop tuning can be aided by a calibration measurement made when the system is powered up, periodically, or each time a channel is changed, or each time a call is initiated. The calibration measurement can update the table of values or correction factors.
By implementing the varactors on-chip, techniques for compensating for environmental changes may be improved. Specifically, the temperature coefficients of the on-chip varactors will match very well and this allows the use of a reference varactor whose temperature and temperature coefficient will match very closely with the varactors used in the filters. The capacitance of the reference varactor can be monitored and its tuning voltage can be automatically adjusted to ensure constant capacitance. Alternatively, a full tuning curve can be measured. The reference varactor tuning information can be used to update the tuning voltage of the filter varactors, thereby ensuring very accurate compensation of capacitance drift due to temperature changes, power supply voltage changes, ageing, and other sources of drift.
The Tx and Rx filter topologies are influenced by the relationship of the transmit and receive frequencies. The Tx stop band frequency generally corresponds to the Rx pass band and the Rx stop band should fall into the Tx pass band. For the example shown in FIG. 3 , the Rx pass band is higher in frequency than the Tx pass band.
The varactor capacitance values are interrelated and are determined when the duplexer is synthesized according to system requirements. The values of the voltages that correspond to the capacitance values reside in the calibration state machine or microprocessor. Each filter section produces one null. Therefore, as the number of sections increases, the number of stop band null frequencies increase.
FIG. 4 shows an example of a schematic of the tunable duplexer of the present invention with actual varactor capacitance values and inductor values. The Tx pass band for this example is 824 to 829 MHz and the Tx stop band is 869 to 894 MHz. The Rx pass band is 869 to 874 MHz and the Rx stop band is 824 to 829 MHz.
FIG. 5 shows the response of the filters using the varactor capacitance values and inductor values given in FIG. 4 .
The duplexer of the present invention can be used with transceivers that have selectable frequencies. When the transceiver is tuned to the desired transmit and receive frequencies, the tunable duplexer will also tune to match the frequencies of the transceiver. | A tunable duplexer using voltage-controlled varactors is presented. The center frequency, the pass band, and the stop band are each tunable to meet system requirements. A calibration circuit driving digital to analog converters produces the necessary voltages used in the resonant circuits. The tunable duplexer can be fabricated on a single silicon chip. On-chip transformers can be used to reduce the voltage level of signals in the filters to improve the linearity of the duplexer. | 7 |
TECHNICAL FIELD
The present invention relates to a light reflector, and in more detail, a light reflector for reflecting light from a light source to thereby achieve a high luminance.
BACKGROUND ART
Backlight type liquid crystal displays provided with built-in light sources have a wide market. As one example of such backlight type displays, a typical constitution of a side-light type display unit is shown in FIG. 1 . The unit has a light-guide plate comprising a transparent acryl plate 3 having on one surface thereof a dot-printed plane 2 , a light reflector 1 placed opposing to the dot-printed plane 2 , a diffusing plate 4 placed opposing to the opposite plane of the light-guide plate, and a cold cathode lamp 5 placed in the lateral vicinity of the light-guide plate. In such constitution, light introduced into the light-guide plate from the lateral side thereof causes light emission at the dot-printed plane 2 , to thereby prevent reflection or leakage of the light, which allows the diffusing plate 4 to produce a uniform surface emission of the light.
In such backlight unit, the light reflector functions so as to make an effective use of the light from the light source for display, and thus allows the displays to be adapted to the individual purposes. Since glaring mirror reflection is not preferred in general for the display, and instead it is necessary to provide by scattering reflection a relatively uniform surface luminance to thereby create a natural sight for the user. In particular for the light reflector for use in a liquid crystal display of the side-light type, it is necessary to uniformly reflect the light which otherwise tends to leak backward through the light-guide plate.
It is known from the past to add a white pigment such as titanium oxide or fluorescent brightener to a film composing the light reflector in order to raise the luminance thereof. It is also known to coat a white pigment such as titanium oxide on a metal plate such as aluminum plate to prevent the light transmission and mirror reflection.
As is described in the above, the conventional light reflector has been controlled in the optical functions thereof, such as luminance, through the use of components having optical properties. The present invention, however, shifts a point of view from such use of the optically functional material to the employment of a specific structure of the light reflector per se, to thereby improve the luminance at low cost.
SUMMARY OF THE INVENTION
The present inventors got an idea that, when the light introduced from the lateral side of the light-guide plate is refracted or reflected by the light reflector, a highly efficient reflection will be ensured and thus the luminance can be improved if the light reflector has a number of micro-lenses aligned so as to cover the entire surface thereof, where each micro-lens has an approximately exact circular profile. The present inventors found out that the foregoing problem can be solved at low cost if the function of such micro-lenses are assigned to voids produced in a stretched film, and that a light reflector having a luminance of 1,200 cd/m 2 or above can uniformly reflect the light, which otherwise leaks backward through the light guide plate, to thereby achieve surface emission, which led them to complete the present invention.
That is, the present invention is to provide a light reflector comprising a biaxially stretched film containing a polyolefinic resin and a filler, wherein said filler is an inorganic filler having an average grain size of 0.1 to 8 μm and/or an organic filler having a mean dispersion grain size of 0.1 to 8 μm, said biaxially stretched film has an area stretched factor of 16 to 80, and said light reflector has a luminance of 1,200 cd/m 2 or above.
A volume ratio of the filler to the biaxially stretched film is preferably 3.0 to 35% by volume, and for the case the inorganic filler is used, such inorganic filler preferably comprises calcium carbonate grains having a specific surface area of 20,000 cm 2 /g or above and excluding those with a grain size of 10 μm or above. A ratio L MD /L CD , which is a ratio of stretching factor of said biaxially stretched film in the moving direction L MD to a stretching factor in the crossing direction L CD , is preferably 0.25 to 2.7. The porosity is preferably 15 to 60%, the opacity measured according to JIS (Japanese Industrial Standard) P-8138 is preferably 90% or above. The biaxially stretched film preferably has a multi-layered structure, and may have protective films on the front and/or back surface thereof.
It should now be noted that numerical ranges expressed with “to” in this specification include both end values given before and after “to” as minimum and maximum values, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and features of the invention are apparent to those skilled in the art from the following referred embodiments thereof when considered in conjunction with the accompanied drawing, in which:
FIG. 1 is a schematic sectional view for explaining a method for measuring luminance, where reference numeral 1 is for a light reflector, 2 for a white dot printed plane for reflection, 3 for an acryl plate (light-guiding plate), 4 for a diffusion sheet, 5 for a cold cathode lamp, and 6 for a luminance gauge.
DETAILED DESCRIPTION OF THE INVENTION
The light reflector of the present invention comprises a biaxially stretched film containing a polyolefinic resin and a filler, and features reside in that the filler is an inorganic filler having an average grain size of 0.1 to 8 μm and/or an organic filler having a mean dispersion grain size of 0.1 to 8 μm; that the biaxially stretched film has an area stretched factor of 16 to 80; ant that the light reflector has a luminance of 1,200 cd/m 2 or above. Using a light reflector satisfying these conditions can improve the luminance at low cost and provide a bright backlight.
Constitution and effects of the light reflector according to the present invention will be detailed hereinafter.
Polyolefinic Resin
There is no specific limitation on the polyolefinic resin used for the light reflector of the present invention, and examples of which include ethylene-base resins such as high-density polyethylene and middle-density polyethylene; and propylene-base resins. Two or more of those selected from the above resins may be used in combination. Among the polyolefinic resin, propylene-base resin is particularly preferable in view of chemical resistance and cost.
Examples of available propylene-base resin include propylene homopolymer, and copolymers of propylene as a major component with αolefins such as ethylene, 1-butene, 1-hexene, 1-heptene and 4-methyl-1-pentene. The stereoregularity of the resin is of no specific limitation, where isotactic, syndiotactic and any other stereoregularity to a variety of degrees are allowable. The copolymer may be of binary system, ternary system or quaternary system, and may be a random copolymer or block copolymer.
Such polyolefinic resin is preferably contained in the biaxially stretched film in an amount of 38 to 91.5 wt %, more preferably 44 to 89 wt %, and still more preferably 50 to 86 wt %.
Filler
The filler available in the present invention together with the polyolefinic resin include various types of inorganic and organic fillers.
The inorganic filler can be exemplified as calcium carbonate, fired clay, silica, diatom earth, talc, titanium oxide, barium sulfate and aluminum sulfate.
The organic filler may be made of a material having a melting point (e.g., 170 to 300° C.) or a glass transition point (e.g., 170 to 280° C.) higher than those of the polyolefinic resin, examples of such materials include 6-nylon, 6,6-nylon, cycloolefinic polymer and copolymer of cycloolefin with ethylene.
A single filler may be selected for use in the biaxially stretched film from the above inorganic or organic fillers, or two or more fillers may be selected for combined use. For such combined use, it is also allowable to mix the inorganic and organic fillers.
For the purpose of regulating the size of voids produced by the stretching described later, the average grain size of the foregoing inorganic filler or the mean dispersion grain size of the organic filler is preferably 0.1 to 8 μm, respectively. The average grain size or the mean dispersion grain size exceeding the above range will result in non-uniform voids, and those lower than the above range will fail in obtaining desired voids.
All of “average grain size of the inorganic filler” mentioned in this specification refer to those calculated from the equation below: average grain size ( µm ) = 6 true specific gravity × specific surface area
where, the specific surface area is measured using a measuring instrument (Model SS-100, product of Shimadzu Corporation), and the true specific gravity means the specific gravity of the inorganic filler in a state containing no air.
All of “mean dispersion grain size of the organic filler” mentioned in this specification are obtained by electron microscopic observation of section of the film. More specifically, the values were obtained by embedding the multi-layered stretched resin film in an epoxy resin to be solidified, slicing the resultant solid using a microtome in a direction parallel to the thickness and normal to the major plane of the film, metallizing the cut plane of the slice and observing the embedded porous resin film under a scanning electron microscope at an arbitrary magnification convenient for the observation (e.g., 500× to 2,000×).
In order to produce desirable voids, it is effective to use an inorganic filler having a specific surface area of 20,000 cm 2 /g or above, and excluding grains with a grain size of 10 μm or above (measured using Microtrack, a laser diffraction particle analyzer). In particular, using calcium carbonate grains having such sharp grain size distribution as defined above is preferable.
In order to regulate the amount of voids to be produced by the stretching described later, the amount of compounding the above fillers into the biaxially stretched film is preferably selected in a range from 3.0 to 35% by volume, and more preferably from 4.0 to 30% by volume. The amount of compounding of the filler lower than the above range tends to make it difficult to obtain a sufficient quantity of voids, and, exceeding the above range tends to cause wrinkle by folding due to a poor rigidity.
The biaxially stretched film used in the present invention may be of a mono-layered structure or multi-layered structure, where more preferable is the latter since it allows a broader choice of blend composition at the time of film forming. For the case that the multi-layered structure is a three-layered structure of surface layer/base layer/back layer, and that the base layer contains a propylene-base resin as a major resin, the stretching property of such layer is preferably improved by adding 3 to 25 wt % of a resin, such as polyethylene or ethylene-vinyl acetate copolymer, having a melting point lower than that of the propylene-base resin. The base layer may be added with titanium dioxide as an inorganic filler in an amount of 0.5 to 10 wt %, and more preferably 0.5 to 8.5 wt %. The surface layer and the back layer may be added with titanium dioxide as an inorganic filler in an amount less than 1 wt %, and more preferably 0.1 to 0.9 wt %. The amount of titanium dioxide exceeding the upper limit of the amount of compounding will ruin the whiteness to thereby degrade the luminance, so that the color tone and the contrast in displayed image on the liquid crystal display device tend to become unclear.
The thicknesses of the surface layer and the back layer are preferably 0.1 μm or above, more specifically 0.1 μm or above and less than 1.5 μm, which is preferably less than 15%, more preferably 1 to 10%, and still more preferably 1 to 5%, of the total thickness of the light reflector.
Additives
The biaxially stretched film used for the light reflector of the present invention may optionally be blended with a fluorescent brightener, stabilizer, photo-stabilizer, dispersion aid or lubricant. The stabilizer may be 0.001 to 1 wt % of steric-hindrance phenols, phosphorus-containing compounds or amine-base compounds; the photo-stabilizer may be 0.001 to 1 wt % of steric-hindrance amine-base compounds, benzotriazole-base compounds or benzophenone-base compounds; the dispersion aid for the inorganic filler may be 0.01 to 4 wt % of silane coupling agent, higher aliphatic acids such as oleic acid and stearic acid, metal soap, and polyacrylic acid and polymethacrylic acid or salts thereof.
Forming
The compound containing the polyolefin-base resin and the filler can be formed by the general biaxial stretching process. In a typical biaxial stretching process, the molten resin is extruded in a sheet form using a single-layered or multi-layered T-die or I-die connected to a screw extruder, the obtained sheet is then stretched in the moving direction, which is effected by difference between peripheral speeds of roll groups, and stretching in the crossing direction using a tenter oven, where simultaneous biaxial stretching is possible if the tenter oven is combined with a linear motor.
The stretching temperature is preferably lower by 2 to 60° C. than the melting point of the polyolefinic resin to be employed, and it is typically selected within a range from 152 to 164° C. for the case a propylene homopolymer (m.p. 155-167° C.) is used, and within a range from 110 to 120° C. for high-density polyethylene (m.p. 121-134° C.). The stretching speed is preferably 20 to 350 m/min.
In order to regulate the size of the voids to be produced within the biaxially stretched film, the area stretched factor, which is expressed as (stretching factor in the moving direction L MD )×(stretching factor in the crossing direction L CD ), is preferably within a range from 16 to 80, and more preferably 25 to 70.
In order to regulate the aspect ratio of the voids produced within the biaxially stretched film, a ratio L MD /L CD , which is a ratio of stretching factor in the moving direction L MD to a stretching factor in the crossing direction L CD , is preferably selected within a range from 0.25 to 2.7, and more preferably from 0.35 to 2.3.
The area stretching factor and the L MD /L CD out of the above ranges tend to make it difficult to obtain micro-voids having a shape of approximately exact circle.
In order to regulate the quantity per unit volume of the voids produced within the biaxially stretched film, the porosity is preferably selected within a range from 15 to 60%, and more preferably from 20 to 55%.
The “porosity” in the context of this specification means a value calculated from the equation (1) shown below, in which ρ 0 is the true density, and ρ is the density of said biaxially stretched film, calculated according to JIS P-8118.
The true density is approximately equal to pre-stretching density unless otherwise the pre-stretching material contains a large volume of air.
The biaxially stretched film for use in the present invention has a density generally within a range from 0.55 to 1.20 g/cm 3 , where the density becomes lower and the porosity becomes larger as the amount of the voids increases. A larger porosity desirably improves the reflective characteristics of the surface. porosity ( % ) = ρ 0 - ρ ρ 0 × 100
The post-stretching thickness of the biaxially stretched film is preferably 50 to 400 μm, and more preferably 80 to 300 μm. The thickness smaller than the above range tends to promote backward leakage of the light, and the thickness exceeding the above range undesirably increases the thickness of the backlight unit.
The opacity (JIS P-8138) in the context of the present invention is preferably 90% or above, and more preferably 95% or above. The opacity less than 90% tends to promote backward leakage of the light.
Protective Layer
While the obtained biaxially stretched film can be available as the light reflector of the present invention without further processing, it is also allowable to provide a protective layer on the front surface and/or back surface of the film insofar as it does not ruin optical properties thereof, to thereby protect the film from scratches or foul possibly occur during the fabrication, processing or usage. The protective film can be provided on either side or both sides of the biaxially stretched film.
Method for forming the protective layer include such that co-extruding molten materials of the film and the protective layer using a multi-layered T-die or I-die, and biaxially stretching the obtained stack; such that stretching the film in either direction, extruding thereon a molten material of the protective layer, and stretching the obtained stack in the other direction; and such that biaxially stretching the film, directly or indirectly coating thereon a paint material of the protective layer, and then drying or curing the obtained paint film.
The same polyolefin-base resin and filler with those for the light reflector are available for the protective layer also for the case that the protective layer is stretched together with the film in either direction or both directions. The foregoing additives are also available.
The protective layer formed by post-stretching coating is typically made of a silicone-base material or fluorine-containing material. Such protective layer formed by coating may further be provided on the protective layer formed by stretching together with the film.
The coating may be performed using a roll coater, blade coater, bar coater, air knife coater, size press coater, gravure coater, reverse coater, die coater, lip coater, spray coater or so. The coating is optionally followed by smoothing, drying for removing excessive water or hydrophilic solvent, or curing with the aid of heat, light or electron beam.
The thickness of the protective layer for the light reflector is preferably selected within a range from 0.2 to 80 μm per one side, and more preferably from 2 to 60 μm, so as not to ruin optical properties of the biaxially stretched film.
It is also allowable to provide on at least one side of the protective layer an anchor coat layer and a metallized film stacked in this order to prevent the backward light leakage. This is generally accomplished by coating a polyester-base or polyurethane-base anchor coating material on the protective layer in a dry weight of 0.03 to 5 g/m 2 , and then vapor-depositing a metal to form the metallized film.
Aluminum is a most general material for use in the vapor deposition, where the thickness of the metallized film is preferably 0.025 to 0.5 μm, and more preferably 0.03 to 0.1 μm.
Light Reflector
Shapes of the light reflector of the present invention are not specifically be limited, and can properly be selected depending on the purpose or style of use. While the light reflector is generally used in a form of plate or film, those having any other forms will be included in the scope of the present invention insofar that they are used as the light reflectors.
The light reflector of the present invention is quite valuable as that composing a display device of the backlight type, in particular of side light type. In a liquid crystal display device based on the side light type using such light reflector of the present invention, the light can uniformly be reflected by such light reflector to thereby achieve surface emission, and to thereby create a natural sight for the user.
The light reflector of the present invention is not only applicable to such liquid crystal display device of the backlight type, but also to a device of power-saving type which is designed to reflect room light without using a built-in light source.
The present invention will now be detailed referring to specific Examples, Comparative Examples and Test Examples. Materials, amount of use thereof, ratio of use, operations or the like can properly be modified without departing from the spirit of the present invention. Thus it is to be understood that the present invention is by no means limited to the specific Examples explained below.
EXAMPLES 1 TO 4, COMPARATIVE EXAMPLES 1 AND 2
A composition (A) containing a propylene homopolymer, a high-density polyethylene and a heavy calcium carbonate in the amounts listed in Table 1, and a composition (B) containing a propylene homopolymer and a heavy calcium carbonate in the amounts listed in Table 1 were separately kneaded at 250° C. under fusion using three units of extrusion machine, where two units for the composition (B). The fused materials were then sent to a single co-extrusion die, stacked within such die so that the composition (B) is stacked on both sides of the composition (A), extruded into a sheet form, and then cooled to approx. 60° C. to thereby obtain a stack.
The stack is re-heated to 145° C., and stretched at a magnification listed in Table 1 in the moving direction effected by difference in the peripheral speeds of a number of roller groups; and again heated up to 150° C. and stretched at a magnification listed in Table 1 in the crossing direction using a tenter. The stretched film was further annealed at 160° C., cooled down to 60° C., and having the both edge portions slit off, to thereby produce a three-layered light reflector having a thickness listed in Table 1.
In Comparative Examples 1 and 2, the stack was extruded 6-fold only in the moving direction by properly adjusting the lip aperture of the die, to thereby obtain the uniaxially stretched film having a thickness listed in Table 1.
EXAMPLE 5
The stacked material is re-heated to 145° C., and stretched 5-fold in the moving direction effected by difference in the peripheral speeds of a number of roller groups.
A composition (C) containing a propylene homopolymer and a heavy calcium carbonate in the amounts shown in Table 1 was kneaded under fusion using two units of extrusion machine, and the fused material was then stacked within a co-extrusion die so that the composition (B) is stacked on both sides of the 5-fold stretched sheet. The obtained stack was heated to 160° C. and then stretched 7.5-fold in the crossing direction, to thereby obtain a light reflector having on both sides thereof protective films.
EXAMPLES 6 TO 8
A composition (A) containing a propylene homopolymer, a high-density polyethylene, a heavy calcium carbonate and titanium dioxide having an average grain size of 0.2 μm in the amounts listed in Table 1, and a composition (B) containing a propylene homopolymer, a heavy calcium carbonate and titanium dioxide having an average grain size of 0.2 μm in the amounts listed in Table 1 were separately kneaded at 250° C. under fusion using three units of extrusion machine, where two units for the composition (B). The fused materials were then sent to a single co-extrusion die, stacked within such die so that the composition (B) is stacked on both sides of the composition (A), extruded into a sheet form, and then cooled to approx. 60° C. to thereby obtain a stack.
TEST EXAMPLES
With regard to the individual light reflectors obtained in Examples 1 to 8 and Comparative Examples 1 and 2, the opacity, porosity and luminance were measured. Results of the measurements were summarized in Table 1.
The opacity was measured using a test instrument Model SM-5 (a product of Suga Test Instruments Co., Ltd.) according to JIS P-8142.
The porosity was calculated from the foregoing equation, where density and true density were previously measured according to JIS P-8118.
The luminance was measured as shown in FIG. 1, in which the light reflector 1 was set opposing to the white dot printed plane 2 of the acryl plate 3 (light guide plate), the light from the cold cathode lamp 5 (inverter unit, 12 V, 6 mA bulb current, product of Harison Electric Corporation) was introduced into the acryl plate 3 , and the reflected light was detected using a luminance gauge 6 (Model LS110, a product of Minolta Co., Ltd.).
Results of these measurements were shown in Table 1.
TABLE 1
Constitution of light reflector
Biaxially stretched film
Provi-
Thickness (μm)
Vol-
sion
Thickness
ume
of pro-
of layers
Evaluation of
Surface and back
ratio
tect-
Stretching factor
(B)/(A)/(B)
light reflector
Base layer (A)
layers (B)
of
ive
(-fold)
Total
or
Opa-
Poro-
Lumi-
Composition (wt %)
Composition (wt %)
filler
layer
Mov-
Cros-
thick-
(C)/(B)/(A)/
city
sity
nance
PP1
HDPE
CaCO 3
TiO 2
PP2
CaCO 3
TiO 2
(%)
(C)
Area
ing
sing
ness
(B)/(C)
(%)
(%)
(cd/m 2 )
Ex. 1
65
10
(b) 25
0
70
(b) 30
0
10.1
no
45
5
9
135
0.5/134/0.5
98
47
1250
Ex. 2
65
10
(a) 25
0
70
(b) 30
0
10.1
no
45
5
9
135
0.5/134/0.5
99
47
1340
Ex. 3
60
10
(a) 30
0
97
(b) 3
0
12.4
no
52.3
5.5
9.5
80
0.5/79/0.5
98
47
1300
Ex. 4
75
10
(b) 15
0
97
(b) 3
0
5.5
no
32
4
8
120
1/118/1
99
36
1240
Ex. 5
75
10
(b) 15
0
97
(b) 3
0
12.0
yes
37.5
5
7.5
200
40/1/118/
96
31
1220
1/40
Ex. 6
62
10
(a) 25
3
70
(a) 29.5
0.5
10.8
no
45
5
9
135
0.5/134/0.5
99
47
1360
Ex. 7
62
10
(c) 25
3
70
(c) 29.5
0.5
11.2
no
45
5
9
135
0.5/134/0.5
99
47
1350
Ex. 8
62
10
(c) 25
3
70
(b) 29.5
0.5
11.2
no
45
5
9
135
0.5/134/0.5
99
47
1340
Comp.
60
10
(b) 30
0
97
(b) 3
0
10.3
no
6
6
—
80
8/64/8
76
15
900
1
Comp.
65
10
(b) 25
0
70
(b) 30
0
10.3
no
6
6
—
135
7/121/7
93
17
1150
2
Protective layer composed of 55 wt % of PP2 and 45 wt % of CaCO 3
PP1: propylene homopolymer, MFR = 0.8 g/10 min (230° C., 2.16 kg load), (product of Nihon Polychem Co., Ltd.)
PP2: propylene homopolymer, MFR = 4 g/10 min (230° C., 2.16 kg load), (product of Nihon Polychem Co., Ltd.)
HDPE: high-density polyethylene (HJ381P, product of Nihon Polychem Co., Ltd.)
Types of CaCO 3
(a): heavy calcium carbonate, average grain size = 0.89 μm, specific surface area = 25,000 cm 2 /g, excluding grains with a grain size of 5 μm or above
(b): heavy calcium carbonate, average grain size = 1.8 μm, specific surface area = 12,500 cm 2 /g,
(c): heavy calcium carbonate, average grain size = 0.97 μm, specific surface area = 23,000 cm 2 /g, excluding grains with a grain size of 7 μm or above
TiO 2 : titanium dioxide, average grain size = 0.2 μm.
As is clear from the above, the light reflector of the present invention can improve the luminance at low cost without relying upon components having optical properties. Using the light reflector of the present invention will thus successfully provide a bright backlight type device with a luminance improved from that in the conventional device. | A light reflector comprising a biaxially stretched film containing a polyolefinic resin and a filler, wherein said filler is an inorganic filler having an average grain size of 0.1 to 8 μm and/or an organic filler having a mean dispersion grain size of 0.1 to 8 μm, and said biaxially stretched film has an area stretched factor of 16 to 80, and having a luminance of 1,200 cd/m 2 or above is disclosed. A specific feature of such light reflector of the present invention resides in that improvement in the luminance achieved at low cost is ascribable to the structural feature thereof rather than to the composition. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of Ser. No. 12/166,893 filed on Jul. 2, 2008, which claims the benefit of priority from Japanese Patent Application No. 2007-177983 filed on Jul. 6, 2007, the entire contents of all are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a casting aluminum alloy and a heat treatment method thereof. More specifically, the present invention relates to an aluminum alloy suitably used for a member for which both of an excellent high cycle fatigue strength and an excellent thermal fatigue strength are required, to a casting made of the alloy, and a manufacturing method of the casting. Moreover, the present invention relates to an internal combustion engine cylinder head composed of the aluminum alloy and manufactured by the manufacturing method of the casting.
[0004] 2. Description of the Related Art
[0005] As a casting alloy that has a complicated shape, for which excellent mechanical properties are required, heretofore, aluminum alloy castings have been used, which are of Al-Cu-Si series defined as AC2A, AC2B and AC4B in JIS H 5202, and of Al-Mg-Si series defined as AC4C and AC4CH therein. As castings of these alloys, there are a cylinder head, a cylinder block and the like for an internal combustion engine.
[0006] In these castings, as disclosed in Japanese Patent Laid-Open Publication No. 2006-169594, it is frequent that casting bodies are used, which have been subjected to T6 treatment (aging treatment at a tempering temperature, at which the maximum strength is obtained, after solution heat/quenching treatment) or T7 treatment (treatment for ensuring dimensional stability by overaging after solution heat/quenching treatment) for the purpose of enhancing strength and ductility.
[0007] However, in such a conventional internal combustion engine cylinder head, as engine power has been increased and the cylinder head has been thinned aiming at weight reduction of a vehicle body in recent years, a cyclic stress has tended to be increased. In addition, the cylinder head has had a structure in which a high residual stress generated at the time of the T6 or T7 heat treatment is locally concentrated. Accordingly, in the aluminum alloy casting as described above, it cannot be said that elongation thereof as alternative properties of the high cycle fatigue strength and the thermal fatigue strength is sufficient, and there has been a problem of an increased possibility of a fatigue crack occurrence. Such fatigue cracks may occur from stress-concentrated portions of a top deck and water jacket of the cylinder head, and from a high-temperature portion of an inter-valve portion in a combustion chamber.
[0008] The present invention has been made focusing attention on the above-described problem in the conventional aluminum alloy casting. It is an object of the present invention to provide a casting aluminum alloy that is excellent in elongation as the alternative properties of the thermal fatigue strength and the high cycle fatigue strength and is suitably usable for a casting for which both of the excellent high cycle fatigue strength and the excellent thermal fatigue strength are required, for example, an internal combustion engine cylinder head, to provide a casting made of the aluminum alloy, to provide a manufacturing method of the casting, and further, to provide an internal combustion engine cylinder head composed of the aluminum alloy casting, and to provide an internal combustion engine cylinder head manufactured by the manufacturing method of the casting.
SUMMARY OF THE INVENTION
[0009] As a result of repeating assiduous studies on alloy components, a heat treatment method and the like in order to achieve the above-described objects, the inventors of the present invention found out that the above-described problem can be solved by specifying each of Si, Cu and Mg contents, by performing the T7 treatment for the obtained alloy casting, and so on. In such a way, the inventors came to accomplish the present invention.
[0010] Specifically, the present invention has been made based on the above-described finding. A casting aluminum alloy according to the present invention includes: in terms of mass ratios, 4.0 to 7.0% of Si, 0.5 to 2.0% of Cu, 0.25 to 0.5% of Mg, no more than 0.5% of Fe, no more than 0.5% of Mn, and further, at least one component selected from the group consisting of Na, Ca and Sr, each content of which is 0.002 to 0.02%; and Al and inevitable impurities, which are residues.
[0011] Moreover, in addition to the components ranging from Si to Sr, the casting aluminum alloy according to the present invention further includes: at least one component selected from the group consisting of Ti, B and Zr, each content of which is 0.005 to 0.2% in terns of the mass ratio. Further more, an aluminum alloy casting according to the present invention is characterized in that the aluminum alloy casting is composed of the above-described alloy of the present invention. Moreover, a method for manufacturing an aluminum alloy casting according to the present invention includes: performing, for the above-described aluminum alloy casting, T7 treatment, that is, solution heat treatment for rapidly cooling the aluminum alloy casting after holding the aluminum alloy casting at a temperature of 500 to 550° C. for 2.0 to 8.0 hours; and performing, for the above-described aluminum alloy casting, aging treatment for cooling the aluminum alloy casting after holding the aluminum alloy casting at a temperature of 190 to 250° C. for 2.0 to 6.0 hours.
[0012] Moreover, a cylinder head for an internal combustion engine according to the present invention is characterized in that the cylinder head is composed of the above-described aluminum alloy casting according to the present invention, and further, is characterized in that the cylinder head is manufactured by the above-described manufacturing method, in other words, is subjected to the above-described T7 treatment.
[0013] In accordance with the present invention, since each of Si, Cu and Mg, which are contained in the casting aluminum alloy, is limited to the specific range, and so on, the elongation of the casting by the alloy concerned can be enhanced, and the casting excellent in both of the high cycle fatigue strength and the thermal fatigue strength, for example, the internal combustion engine cylinder head excellent therein can be obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a graph showing influences of a Si content and a Cu content, which are given to a generated amount of casting defects, as results of a shrinkage test for a casting aluminum alloy.
[0015] FIG. 2 shows high cycle fatigue strength, fracture elongation and hardness Rockwell B-scale (HRB) of test pieces.
[0016] FIG. 3 shows high cycle fatigue strength, fracture elongation, and hardness Rockwell B-scale (HRB) of test pieces.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] A description will be made below in detail of a casting aluminum alloy of the present invention and an aluminum alloy casting made of the alloy together with limitation reasons such as alloy components and heat treatment conditions, functions thereof, and the like. Note that, in this specification, “%” represents a mass percent unless otherwise specified.
(1) Si Content: 4.0 to 7.0%
[0018] Si (silicon) has a function to enhance castability. Accordingly, in the case of casting an article, such as a cylinder head, having a complicated shape and a thin-walled portion, it is necessary to add some amount of Si to the article from a viewpoint of fluidity of molten metal (molten aluminum alloy), that is, moldability of a casting. Specifically, if a Si content is less than 4.0%, then the fluidity of the molten aluminum alloy becomes insufficient. Moreover, a semisolid region is spread, shrinkage cavities are dispersed to cause porosities, and a shrink breakage becomes prone to occur. Moreover, Si has a function to enhance a mechanical strength, abrasion resistance and vibration resistance of a casting material.
[0019] However, as the Si content is increased, thermal conductivity and ductility of the alloy are decreased, leading to a deterioration of thermal fatigue properties. If the Si content exceeds 7.0%, then elongation of the alloy is decreased significantly, and moreover, the alloy begins to exhibit a tendency to concentrate the shrinkage cavities. Accordingly, an occurrence of porous cavities is sometimes seen.
[0020] FIG. 1 is a graph showing results of a shrinkage test. Specifically, FIG. 1 shows results, each of which is of measuring a casting defect rate from a difference between a standard specific gravity of the alloy and a specific gravity of a bottom center of a test piece, which was measured by the Archimedean method when the test piece was cast into a conical shape. From this graph, it is understood that casting defects (sum of the porosities and the porous cavities) become the minimum when the Si content is 4.0 to 7.0%, and in addition, an amount of the casting defects is reduced as a Cu content becomes smaller.
[0021] Note that it is more preferable that the Si content be within a range of 5.0 to 7.0%.
[0000] (2) Cu content: 0.5 to 2.5%
[0022] Cu (copper) has an effect to enhance the mechanical strength of the aluminum alloy. This effect becomes significant when a Cu content becomes 0.5% or more. However, as the Cu content is increased, the thermal conductivity and ductility of the alloy are decreased, leading to the deterioration of the thermal fatigue properties. Moreover, as the Cu content is increased, a coagulation folio of the alloy becomes like mush, and the shrinkage cavities are dispersed to cause the porosities.
[0023] As apparent from FIG. 1 , if the Si content is unchanged, then the amount of casting defects is increased as the Cu content is increased, and adverse effects from such an increase of the Cu content become significant by the fact that the Cu content exceeds 2.5%. Accordingly, the Cu content is set within a range of 0.5 to 2.5%, more preferably within a range of 0.8 to 1.3%.
(3) Mg: 0.25 to 0.5%
[0024] If Mg (magnesium) is added to the alloy, then the alloy exhibits a tendency to increase a tensile strength and hardness by being subjected to heat treatment, and to decrease a thermal fatigue strength and elongation thereby. If Mg is added excessively, then Mg is precipitated as Mg 2 Si to decrease the thermal fatigue strength and the elongation. Accordingly, an added amount of Mg is set within a range of 0.25 to 0.5%, more preferably within a range of 0.3 to 0.4%.
[0025] By setting the added amount of Mg within the above-described range, a matrix of the alloy is strengthened by aging precipitation of an inter mediate phase of Mg 2 Si. Meanwhile, if the Mg content exceeds 0.5%, then a surface oxidation amount of the molten aluminum alloy is significantly increased to cause a malfunction that inclusion defects are increased.
[0000] (4) Fe: 0.5% or less
[0026] Fe (iron) is precipitated as a needle-like iron compound, and in general, adversely affects the tensile strength, the fatigue strength, the they dial fatigue strength, the elongation, and the like. Accordingly, an upper limit value of a Fe content is set at 0.5%.
[0027] Note that, since Fe is a harmful component as described above, a smaller content thereof is desirable. It is preferable that the Fe content be set at 0.2% or less. Moreover, it is ideal Fe content be substantially 0%.
[0000] (5) Mn: 0.5% or less
[0028] By adding Mn (manganese) to the alloy, a shape of such a crystallized object containing Fe can be changed from the needle shape that is prone to bring up the decrease of the strength to a massive shape that is less likely to cause a stress concentration.
[0029] If a Mn content is larger than necessary, then an amount of the iron compound (Al-Fe, Mn-Si) is increased. Accordingly, the Mn content is set at 0.5% or less, desirably 0.2% or less. Note that a ratio of Fe: Mn becomes preferably 1:1 to 2:1.
(6) One or More of Na, Ca and Sr: 0.002 to 0.02% Per Each
[0030] In particular, with regard to a material of the cylinder head, in order to enhance thermal fatigue resistance thereof, it is desirable that one or more of these components (Na, Ca and Sr) be added to the alloy, thereby microfabricating Si particles in a cast texture.
[0031] By the improvement treatment for the Si particles, mechanical properties of the alloy, such as the tensile strength and the elongation, are enhanced, and the thermal fatigue strength is also enhanced. However, if the above-described components are added in large amounts, then a region occurs, where a band-like coarse Si phase is crystallized. Such an occurrence of the coarse Si phase is called overmodification, and sometimes results in the decrease of the strength. Accordingly, in the case where these components described above are added to the alloy, a content of each thereof is set within a range of 0.002 to 0.02%. Note that, for a surface of a combustion chamber, where the thermal fatigue strength is an important subject, it is desirable that the alloy be rapidly cooled and coagulated, thereby reducing dendrite arm spacing to 30 pm or less.
(7) One or More of Ti, B and Zr: 0.005 to 0.2% Per Each
[0032] Each of these components (Ti, B and Zr) is an effective component for microfabrication of crystal particles of the cast texture, and accordingly, is added to the alloy according to needs within a range of 0.005 to 0.2%. Moreover, these components are added in a component range where the amount of the casting defects is large, whereby the porous cavities are dispersed, and the shrinkage cavities are removed.
[0033] In the case where the added amount of each of these components is less than 0.005%, no effect is brought up. In the case where the added amount exceeds 0.2%, Al-Fe, Al-B, Al-Zr, TiB, ZrB and the like, which become cores of the crystal particles, are coagulated, whereby a risk of causing the defects is increased.
[0000] (8) T7 Treatment (Solution Heat Treatment, and then Stabilization Treatment)
[0034] Solution heat treatment: rapid cooling after holding at 500 to 550° C. for 2.0 to 8.0 hours
[0035] Aging treatment: air cooling after holding at 190 to 250° C. for 2.0 to 6.0 hours
[0036] Usually, in order to enhance the strength, the cylinder head is subjected to T6 treatment (solution heat treatment, and then artificial aging treatment) or T7 treatment. In the present invention, though being slightly inferior in strength to the T6 treatment, the T7 treatment (solution heat treatment, and then stabilization treatment) is performed since the enhancement of the thermal fatigue strength, the reduction of the residual stress, and the dimensional stability, which are necessary for the cylinder head, are obtained.
[0037] Specifically, the casting aluminum alloy of the present invention, which has the above-described component composition, is subjected to the solution heat treatment under conditions where the temperature is 500 to 550° C. and the treatment time is 2.0 to 8.0 hours, and to the aging treatment under conditions where the temperature is 190 to 250° C. and the treatment time is 2.0 to 6.0 hours.
[0038] By the T7 treatment as described above, there can be obtained 50 HRB as hardness necessary from a viewpoint of preventing permanent sett in fatigue of a seating surface of a head bolt and a gasket seal surface and ensuring abrasion resistance on a fastening surface of the cylinder head with a cylinder block, a sliding portion of a camshaft, and the like.
[0039] When the time of the solution heat treatment is ensured sufficiently, eutectic Si comes to have a roundish shape by diffusion, whereby the stress concentration is relieved, and the mechanical properties such as the ductility will be improved.
EXAMPLES
[0040] The present invention will be described below more in detail based on examples; however, the present invention is not limited to these examples.
(1) Boat-Like Sample Casting Test
[0041] Aluminum alloys with compositions shown in FIG. 2 were molten by an electric furnace, and were subjected to the microfabrication treatment and the Si improvement treatment, and thereafter, boat-like samples with dimensions of 190×40×25 mm were cast. Then, the boat-like samples were subjected to the T7 treatment (solution heat treatment at 530° C. for 5 hours, and then aging treatment at predetermined temperature between 180 to 260° C. for 4 hours). Thereafter, fatigue test pieces and tensile test pieces were cut out of the treated boat-like samples. For each of the test pieces, the high cycle fatigue strength and the fracture elongation were measured, and the hardness Rockwell B-scale (HRB) was measured.
[0042] Results of these are shown in FIG. 2 in combination. With regard to target values of these, a target value of the high cycle fatigue strength is set at 100 MPa or more, a target value of the elongation as the alternative properties of the thermal fatigue strength is set at 10.0% or more, and a target value of the hardness is set at 50 HRB or more.
[0043] Note that, in the high cycle fatigue test, an Ono-type rotating bending fatigue test machine was used, and the number of revolutions thereof was set at 3600 rpm. Then, the fatigue strength of each test piece was evaluated based on a stress amplitude value when the number of repeated bending cycles up to the fracture was 10 7 times.
[0044] As apparent from FIG. 2 , in Examples 1 to 9 where the test pieces contained the alloy components with mass percents of the predetermined ranges and were subjected to the T7 treatment at the aging temperatures of 200 to 240° C., it was confirmed that the test pieces exhibited good performance in all of the high cycle fatigue strength, the fracture elongation and the hardness.
[0045] As opposed to this, in Comparative examples 1 to 10 where the alloy components and the aging temperatures went out of the ranges defined by the present invention, and in Conventional materials 1 and 2 using the AC4CH alloy and the AC2A alloy, which have been used as the conventional cylinder head material, it was found out that at least one of the properties, that is, the fatigue strength, the fracture elongation and the hardness, was low in each test piece thereof, whereby it was impossible to obtain such strength as meeting requirements for a cylinder head material of a high-performance engine.
(2) Cylinder Head Casting Test
[0046] The alloys showing relatively good performance in the boat-like sample casting test were chosen from the above described Examples and Comparable Examples. Then, actual bodies of the cylinder heads of the alloys chosen were cast in a metal die, and were subject to the T7 treatment corresponding to that in the boat-like sample casting test. Thereafter, fatigue test pieces and tensile test pieces were cut out of positions of the cylinder heads cast and treated, which were in the vicinities of the surfaces of the combustion chambers, and were subjected to measurements of the high cycle fatigue strength and the fracture elongation in a similar way to the above, and in addition, were subjected to measurements of the hardness Rockwell B-scale (HRB).
[0047] Results of these are shown in FIG. 3 . With regard to target values in this case, a target value of the high cycle fatigue strength is set at 85 MPa or more, and a target value of the hardness is set at 50 HRB or more.
[0048] Moreover, with regard to the thermal fatigue strength, a simple thermal fatigue test in which a temperature cycle was set as 40° C.-270° C.-40° C. was carried out under completely restrained conditions by using flat test pieces added with V notches, and a target value of results of the simple thermal fatigue strength was set at no less than 100 that is a thermal fatigue lifetime of a TIG-remolten article from the conventional AC2A alloy. As apparent from the results shown in FIG. 3 , also in the castings of the actual bodies of the cylinder heads, it was confirmed that the test pieces in Examples 2-2 and 6-2 corresponding to Examples 2 and 6 of the boat-like sample casting test exhibited good performance in the high cycle fatigue strength, the thermal fatigue lifetime and the hardness, and met, at a high level, the properties required for the cylinder head.
[0049] As opposed to this, though relatively good evaluation results were obtained by the boat-like samples in Comparative examples 4-2 and 8-2 corresponding to Comparative examples 4 and 8 of the boat-like sample casting test, the fatigue strength and the thermal fatigue lifetime were decreased in Comparative example 4-2 owing to an influence of the casting defects, which did not appear in the boat-like samples, since the actual body of the cylinder head was thick-walled.
[0050] Meanwhile, with regard to Comparative example 8-2 where the target value was almost achieved in the boat-like sample casting test, the strength thereof was also low in the actual body test. This is considered to be because Si was not improved by Sr. | A method for manufacturing an aluminum alloy casting includes obtaining the aluminum alloy casting by casting an aluminum alloy into a mold, performing solution heat treatment, rapidly cooling the casting, performing aging treatment, and cooling the casting. The aluminum alloy includes, in terms of mass ratios, 4.0 to 7.0% of Si, 0.5 to 2.0% of Cu, 0.25 to 0.5% of Mg, no more than 0.5% of Fe, and no more than 0.5% of Mn, and at least one component selected from the group consisting of 0.002 to 0.02% of Na, 0.002 to 0.02% of Ca and 0.002 to 0.02% of Sr, a remainder being Al and inevitable impurities. An internal combustion engine cylinder head is composed of the aluminum alloy casting and manufactured by the method of the casting. The aluminum alloy casting is suitable for applications requiring superior elongation, high cycle fatigue strength and high thermal fatigue strength. | 2 |
This application is a continuation of Ser. No. 07/311,144 filed Dec. 15, 1989, now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to a process for the production of pigment/plastic premixes.
As is generally known, titanium dioxide is the most frequently used pigment in the pigmenting of various synthetic products. It can be applied in the forms referred to as rutile or anatase modifications. It can also, however, subsequently be surface treated with SiO 2 or Al 2 O 3 . In addition to titanium dioxide, other inorganic, oxidic pigments such as cobalt blue and cobalt violet also find general application.
A condition for the full development of pigment characteristics in a polymer matrix as well as for disturbance-free processing of the pigment polymer compositions, is the complete destruction of the pigment agglomerates and the homogeneous distribution of the pigment particles in the polymer. This is particularly important in the production of thin coatings or foils (generally between 25-50μ thickness), since agglomeration of pigment may disadvantageously lead to the formation of holes, and thus to the tearing of the foils. A good dispersion is therefore necessary to avoid this problem.
For the pigmentation of polyolefin compositions therefore, pigments are not applied as such, but rather in form of pigment/plastic premixes, the so-called "master batches", in which the pigment is present in a form already dispersed. The production of such master batches takes place in a special operational process. Typically suited for this purpose are kneading machines, roller mills and extruders.
According to the presently existing state of the art, various methods for the production of master batches have been proposed (for example, U.S. Pat. No. 4,650,747; JP 60-75 832). All methods are characterized in that they require the use of dispersing agents (for example, salts or esters of higher fatty acids, such as stearates) and the treatment of the titanium dioxide surface by means of organic or inorganic agents (such as, for example, alkyl titanate, alkanolamine, alkylpolysiloxane, and zircoaluminate).
The above-stated methods are disadvantageous in that, despite the use of dispersing agents and other auxiliary agents, complete homogeneous distribution of the pigment particles is not achieved.
The treatment of the pigment particles with various auxiliary agents seems, above all, to be inferior. Evidently, the pigment particles are only incompletely encased by the auxiliary agents and, at least in part for this reason, optimal dispersion is not attained. Pigment agglomerates that remain become noticeable in the extrusion coating, for example by a high sieve residue, obstruction of the nozzles, or holes and tears in the resulting film.
Furthermore, the agglomeration of dispersed particles sets a limit to the pigment concentration in the composition. As a result, the desired or necessary concentrations of pigments can frequently not be attained.
One further disadvantage lies in the application of the dispersing agents themselves. These can exude out of a coating and precipitate on the surface of the foil or film. This results in difficulties in the further processing of the polyolefin coatings or polyolefin parts.
It is generally known that a polymerization can take place on the surface of a polymer body or solid substance, resulting in the encasement of the body or substance. See, for example, the encasement of glass beads with polyacrylonitrile (N. W. Johnston et al, Polym. Prep. Amer. Chem. Soc. Div., Polym. Chem., Vol. 17, number 2, 1976, page 491). In this case, the polymerization is initiated by means of radical initiators.
In the attempt to transfer such a process to pigments, such as, for example TiO 2 , most particles of the pigment were encased by the polymer. However, the disturbances already mentioned in the extrusion coating caused by high portions of pigment agglomerates appeared to be unchanged. In order to obtain a satisfactory distribution of the pigments, usual quantities of auxiliary agents had to be employed.
GENERAL SUMMARY OF THE INVENTION
The invention provides a process by means of which it is rendered successfully possible to ensure a good distribution of pigments in a polyolefin matrix and to ensure a disturbance-free processing of the polymer composition, for example, into a thin film or foil, and to minimize or eliminate the use of dispersing agents to the greatest extent possible.
In order to solve this task according to the invention, a process is proposed in which the polymerization of ethylene, alone as well as with other alpha-olefins, takes place on the surface of the pigment particles to encapsulate the pigment, whereby the polymerization and associated encapsulation takes place after the surface of the pigment particles has been activated by the addition of a compound of a transition element of the IV to VIII secondary group of the periodic system. After activation, the polymerization takes place on the surface of an inorganic oxidic pigment through the application of a metallo-organic catalyst system.
The process in accordance with the invention described here has the following advantages:
No appearance of pigment agglomerates during the production of the master batches;
Homogeneous distribution of pigment particles in the polymer;
Complete disintegration of pigment agglomerates which are possibly present;
Elimination of dispersing and other auxiliary agents.
DESCRIPTION OF THE DRAWING
FIG. 1 qualitatively depicts the pigment distribution in the polymer matrix of the samples obtained in comparative examples A, B, C.
FIG. 2 depicts the distribution of pigment in the polymer matrix in the samples obtained in examples 1 and 7.
DETAILED DESCRIPTION OF THE INVENTION
The process of this invention contemplates the use of the Ziegler or Phillips catalyst systems, such as the following, for example:
TiCl 3 /Al(C 2 H 5 ) 3 ;
TiCl 4 /MgCl 2 /Al(C 2 H 5 ) 3 ;
TiCl 4 /MgCl 2 /Al(i-C 4 H 9 ) 3 ;
TiCl 4 /Mg(OC 2 H 5 ) 2 /Al(C 2 H 5 ) 3 ;
TiCl 4 /Mg(OC 2 H 5 ) 2 /Al(i-C 4 H 9 ) 3 ;
TiCl 4 /Al(C 2 H 5 ) 2 H;
Ti(OC 2 H 5 ) 4 /Al(C 2 H 5 ) 3 ;
VCl 4 /Al(C 2 H 5 ) 3 ;
VCl 4 /Al(C 2 H 5 ) 2 Cl;
VOCl 3 /Al(i-C 4 H 9 ) 2 Cl;
VOCl 3 /Al(C 2 H 5 ) 2 Cl;
(C 6 H 5 ) 2 Zr(CH 3 ) 2 /aluminum oxane;
(C 6 H 5 ) 2 ZrCl 2 /aluminum oxane;
CrO 3 /SiO 2 ;
Zr(C 2 H 5 ) 3 Cl/SiO 2 ;
as well as others.
In a preferred process, the pigment is suspended in a solvent, such as, for example, a hydrocarbon mixture. The pigment surface is activated in the manner mentioned, and then a gaseous olefin is added. After saturation of the suspension with the olefin, the catalyst system is added in order to initiate the desired polymerization.
The polymerization reaction can, however, also be started before the suspension has been saturated with olefin.
A preferred olefin for use in the process is ethylene or an ethylene/alpha-olefin mixture. A small portion of a fluid or solid alpha-olefin can also be added to the suspension before addition of the gaseous olefin.
The Ti-, V-halogenides, and the combinations of both of these are particularly suitable compounds for the activation of the pigment surface. Titanium ester chlorides and various zirconium compounds, such as, for example, biscyclopentadienyl zirconium dimethyl, are suitable for the activation.
Among inorganic oxidic pigments, there are, for example, all titanium dioxide modifications, with or without inorganic and/or organic surface-treatment, ZrO 2 , cobalt blue, cobalt violet, and other mixed oxides, such as alkaline earth titanates or Zn-titanate.
Surprisingly, the performance of polymerization according to this invention leads to a very homogeneous distribution of the pigment particles. It is believed that the chain growth of the polymer takes place not only externally on the surface of the pigment, but also within its pores, by which disintegration of the pigment particle is caused. The pigment fragments caused by such disintegration also appear to be completely encased by the polymer.
In the first instance, however, the encasement or encapsulation of the pigment occurs after the activation of the pigment surface in accordance with the invention. The activating compound can be at least one component of the catalyst system. The start of polymerization occurs thereafter, through the addition of the catalyst system. The superior effect of the invention is evident from FIGS. 2a and 2b, following Example 7.
Equally satisfactory results were observed in the copolymerization of the ethylene with other olefins. In this, the alpha-olefin can be applied with a chain length of up to approximately C 26 -C 28 .
The regulation of the molecular weight of the polymerization attained during the polymerization can take place in the usual manner, through the use, for example, of hydrogen as a regulator substance.
EXAMPLES OF EXECUTION
EXAMPLE 1
100 g of titanium dioxide (Rutile 2073 type, manufactured by Kronos) and 1.5 l of toluene (dried by means of a molecular sieve) were introduced under a nitrogen atmosphere into a 2 liter glass reaction vessel.
The suspension was heated, during agitation, to 80° C., 1.1 g of TiCl 4 as a surface activator added, and subsequently saturated with ethylene. After saturation has taken place, the polymerization was initiated through the addition of a modified Ziegler catalyst system in a concentration of 1×10 -4 mol/l (relative to the titanium content), whereby ethylene was further introduced. The catalyst system used here was prepared in the manner known to those of skill in the art, such as taught in DE 1,795,197, the teachings of which are incorporated here by reference; it is based on Mg(OC 2 H 5 ) 2 /TiCl 4 /Al(i-C 4 H 9 ) 3 with a molar ratio of Al/Ti=125. The polymerization took place at 80° C., an ethylene pressure of 1.15 bar (total pressure=1.5 bar), and an agitator speed of 1250 RPM.
The ethylene concentration amounted to approximately 0.08 mol/l and could be calculated from the ethylene partial pressure.
The polymerization was stopped by interruption of the addition of ethylene, after 100 g of polyethylene had formed. The reaction product (white powder) was filtered off, washed with acetone, and vacuum dried at 60° C.
EXAMPLE 2
The process was carried out as in Example 1, but 0.25 mol/l hexene-1 was added to the suspension in the reactor before the beginning of the polymerization.
The polymerization was stopped after 100 g of polymer had formed. The copolymer contained 4.5 mol % of hexene-1.
EXAMPLE 3
The process was carried out as in Example 1, but 0.25 mol/l of octene-1 was added to the suspension in the reactor before the beginning of polymerization.
The polymerization was stopped after 100 g of polymer had formed. The copolymer contained 2.5 mol % of octene-1.
EXAMPLE 4
The process was carried out as in Example 1, but 0.25 mol/l of tetradecene-1 was added to the suspension in the reactor before the beginning of the polymerization. The copolymer contained 1.5 mol % of tetradecene-1.
EXAMPLE 5
The process was carried out as in Example 1, but 0.25 mol/l of octadecene-1 was added to the suspension in the reactor before the beginning of the polymerization. The copolymer contained 1.5 mol % of octadene-1.
EXAMPLE 6
The process was carried out as in Example 1, but the suspension was mixed in the reactor with 1.1 g VCl 4 as surface activator, and subsequently saturated with ethylene. The polymerization was started by addition of the [VCl 4 /Al(C 2 H 5 ) 2 Cl]-catalyst in a concentration of 1×10 -4 mol/l, relative to the V-content.
EXAMPLE 7
The process was carried out as in Example 1, but 100 g of cobalt blue was used as a pigment.
COMPARATIVE EXAMPLES
A. The process was carried out as in Example 1, but the reaction was started, however, without surface activation.
B. The process was carried out as in Example 1, but the polymerization was started with 0.6 g of t-butylperoxide maleic acid.
C. For purposes of comparison, reference was made to a master batch of the type generally available commercially (with the use of stearates as auxiliary dispersing agents).
The pigment premixes obtained in the Examples A, B, and described in C were compressed into thin discs at 180° C., and X-ray exposures were made of these.
FIG. 1
a) Sample in accordance with comparative Example A;
b) Sample in accordance with comparative Example B;
c) Sample in accordance with comparative Example C.
FIG. 2
a) Sample in accordance with Example 1;
b) Sample in accordance with Example 7.
The foregoing description provides general information and defines preferred embodiments of the invention. However, other variations and modification of the invention are possible within the scope and contribution of the invention. Therefore this patent is to be limited only by the following claims and their equivalents. | There is described a process for the production of pigment/plastic premixes characterized by homogeneous distribution of pigment in a polymer matrix. The invention is based on the polymerization of olefins carried out by means of a process using Ziegler catalyst. Significantly the polymerization occurs on the surface of the pigment particles, after the prior activation of the pigment particles. | 3 |
FIELD OF THE INVENTION
The present invention relates to a method of determining an in-situ stress of an earth formation, the formation being subjected to an in-situ stress state with a first, a second and a third principal stress. The three principal stresses are generally referred to as the first, the second and the third in-situ stress.
BACKGROUND OF THE INVENTION
In the technology of hydrocarbon production from an earth formation it is often required to know the magnitudes and directions of the in-situ stresses in the formation, or at least to have an indication thereof. Such knowledge is needed, for example, for the purpose of achieving wellbore stability, conducting hydraulic fracturing of the formation, geological modelling or preventing sand production. The direction of the in-situ stresses can be determined in several manners such as differential strain analysis, various acoustic techniques, or so-called minifrac tests. In this respect it is to be understood that one of the in-situ stresses is generally in vertical direction and its magnitude is determined from the weight of the overburden. Therefore, in general only the two horizontal in-situ stresses are subject of investigation with respect to direction and magnitude. It has been tried to determine the magnitudes of the horizontal in-situ stresses by measuring strains and using constitutive properties of the rock to determine the stresses. However, the constitutive properties of the rock are generally not accurately known.
It is therefore an object of the invention to determine more accurately the magnitude of one or more of the in-situ stresses in the earth formation.
SUMMARY OF THE INVENTION
In accordance with the invention there is provided a method of determining an in-situ stress of an earth formation subjected to first, second and a third in-situ stresses, wherein a borehole has been drilled into the formation, the borehole containing a borehole fluid inducing a selected pressure to the borehole wall so that in a region of the formation the first in-situ stress is replaced by another stress depending on said selected pressure induced to the borehole wall, the method comprising the steps of:
selecting a sample which has been removed from said region, the sample having first, second and third reference directions which coincide with the respective directions of the first, second and third in-situ stresses prior to removal of the sample from the formation; and
conducting a plurality of tests on the sample whereby in each test the sample is subjected to selected stresses in the reference directions so as to determine a damage envelope of the sample and to determine from the damage envelope at least one of the second and third in-situ stresses, wherein the magnitude of the selected stress in the first reference direction is substantially equal to the magnitude of said another stress.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows a cross-section of a borehole formed in an earth formation, as used in the method of the invention;
FIG. 1A schematically shows the in-situ stresses present in the earth formation;
FIG. 1B schematically shows a core sample taken from the earth formation; and
FIG. 2 schematically shows an in-situ stress diagram used in an embodiment of the method of the invention.
DETAILED DESCRIPTION
It is to be understood that in the context of the present invention the borehole wall includes both the cylindrical part of the borehole wall and the bottom of the borehole. An important aspect of the invention is that account is taken of the severest stress state to which the sample material has been subjected in order to determine the damage envelope. By “severest stress state” is meant the stress state at which the sample material has undergone the largest amount of damage. For example, if the sample is taken from the borehole bottom, the severest stress state is considered to occur just before removing the sample from the formation whereby the magnitude of the vertical in-situ stress at the location of the sample is replaced by a vertical stress equal to the borehole fluid pressure at the borehole bottom plus the weight of the rock material between the borehole bottom and the location of the sample. If the rock material contains pore fluid, the pore fluid pressure is to be deduced from said vertical stress to find the effective vertical stress (which is the stress carried by the rock grains).
In such severest stress state the ratio of the difference between the horizontal in-situ stresses and the vertical stress, to the mean stress is at a maximum.
The damage envelope (also referred to as the damage surface) is formed by the points in three-dimensional stress space at which the onset of additional damage occurs upon further loading of the sample material. The damage surface can be accurately determined from acoustic emission by the sample material at the onset of additional damage. Such acoustic emission is generally referred to as the Kaiser effect as, for example, described in “An acoustic emission study of damage development and stress-memory effects in sandstone”, B J Pestman et al, Int. J. Rock Mech. Min. Sci. & Geomech. Abstr., Vol. 33, No. 6, pp. 585-593, 1996.
The invention will be described hereinafter in more detail and by way of example with reference to the accompanying drawings.
In the detailed description below it is assumed that the earth formation contains no pore fluid, hence the stresses referred to are effective stresses carried by the rock grains. FIG. 1 shows a borehole 1 formed in an earth formation 3 . The undisturbed formation 3 is subjected to in-situ stresses in vertical and horizontal direction, i.e. a vertical compressive stress σ 1 and two horizontal compressive stresses σ 2 , σ 3 as shown in FIG. 1A in relation to a cube-shaped element 5 of the formation 3 . The borehole 1 is filled with a drilling fluid 7 of selected specific weight such that a vertical pressure P is exerted by the drilling fluid 7 on the borehole bottom 11 . Below the borehole bottom 11 is a region 14 of the formation 3 in which the vertical in-situ stress σ 1 at a specific point is replaced by a stress σ 1 ′ equal to the vertical pressure P from the drilling mud 7 plus the weight of the rock material between the borehole bottom 11 and the specific point. The horizontal in-situ stresses σ 2 , σ 3 in region 14 are not (or only very little) affected by the presence of the borehole.
A coring tool (not shown) is lowered through the borehole 1 to take a cylindrical core sample 16 (FIG. 1B) from region 14 of the formation 3 . In FIG. 1 the core sample 16 is indicated in dotted lines to show the location of the rock material of the core sample 16 prior to taking the sample 16 from the formation 3 . The core sample 16 has a first reference direction 18 , a second reference direction 20 and a third reference direction 22 , which reference directions correspond to the respective in-situ stress directions prior to removal of the sample 16 from the formation 3 . Thus, prior to removal of the sample 16 from the formation 3 , reference direction 18 corresponds to vertical, reference direction 20 corresponds to the direction of in-situ stress σ 2 and reference direction 20 corresponds to the direction of in-situ stress σ 3 . During and after removal of the core sample 16 from the formation 3 the compressive stresses acting in the reference directions are altered when the core sample 16 is stored in a container (not shown) containing a fluid at a moderate hydrostatic pressure.
In a next step a series of pressure tests are carried out on the core sample 16 whereby the sample is subjected to compressive stresses S 1 , S 2 , S 3 in respective reference directions 18 , 20 , 22 . The purpose of the tests is to determine the amount of damage which the material of the core sample 16 has undergone prior to removal from the earth formation 3 and to estimate the horizontal in-situ stresses therefrom. The amount of damage can be represented by a damage envelope in three-dimensional stress space (S 1 , S 2 , S 3 ). Considering that the amount of damage of the sample material is determined by the severest stress state to which the sample material has been subjected (i.e. the stress state causing the largest amount of damage) it is an important aspect of the invention that it is taken into account that the severest stress state of the sample material occurred in the presence of the borehole 1 and prior to removing the sample 16 from the formation. Therefore in the severest stress state the principal stresses are σ 1 ′ in reference direction 18 , σ 2 in reference direction 20 and σ 3 in reference direction 22 .
With reference to FIG. 2, the profile of the damage envelope for S 1 =σ 1 ′ is then determined in a series of tests to estimate the magnitudes of horizontal in-situ stresses σ 2 and σ 3 . During the tests the compressive stress S 1 is kept equal σ 1 ′, while stresses S 2 and S 3 are varied until the onset of additional damage occurs. In the example diagram of FIG. 2 the sample 16 is loaded along stress path 24 to point A at which the onset of additional damage occurs. Such onset of additional damage is determined by measuring acoustic emission from the material, based on the Kaiser effect. Next the stresses S 2 and S 3 are changed along stress paths 26 , 28 to point B, along stress paths 28 , 30 , 32 to point C, along stress paths 32 , 34 , 36 to point D, and along stress paths 36 , 38 , 40 to point E, whereby the points B, C, D, E are determined by the onset of additional damage in accordance with the Kaiser effect. The curve formed by points A, B, C, D, E make up the profile of the damage surface for S 1a=σ 1 ′. In conducting the tests, care is to be taken that the severest stress state of the sample material is not exceeded to a significant extent in order to ensure that the damage profile as determined from the tests accurately represents the severest stress state which occurred before the sample 16 was removed from the formation 3 .
The damage profile in the S 1 , S 2 diagram (for S 1 =σ 1 ′) forms a set of points (S 1 , S 2 ) of which each point could, in principle, represent the in-situ stress state (σ 1 , σ 2 , σ 3 ). A selection is made in a known manner to determine from these points the real in-situ stress state, for example by taking a vertex point in the profile as being representative for the real in-situ stresses state.
In case the rock material contains pore fluid, the total stress at a specific point in the formation is the sum of the effective stress (carried by the rock grains) and the pore fluid pressure. The above method then can be applied in a similar manner for the effective in-situ stresses σ 1e , σ 2e and σ 3e . The vertical effective in-situ stress σ 1e at a specific point is replaced by a stress σ 1e ′ equal to the vertical pressure P from the drilling mud 7 plus the weight of the rock material between the borehole bottom 11 and the specific point minus the pore fluid pressure. The magnitudes of the horizontal effective in-situ stresses σ 2e and σ 3e are then determined in a similar manner as described above with reference to σ 2 and σ 3 . | A method is provided for determining an in-situ stress of an earth formation subjected to first, second and a third in-situ stresses, wherein a borehole has been drilled into the formation, the borehole containing a borehole fluid inducing a selected pressure to the borehole wall so that in a region of the formation the first in-situ stress is replaced by another stress depending on the selected pressure induced to the borehole wall. | 4 |
RELATED APPLICATIONS
This application claims the benefit under 37 C.F.R. §119 of prior filed, co-pending Provisional Application No. 60/073,238, filed on Jan. 30, 1998.
BACKGROUND OF THE INVENTION
The invention relates to a method and apparatus for controlling an induction motor, and particularly to a method and apparatus for providing a constant control of air flow, fluid flow, fluid pressure or other physical output of an induction motor in such a way as to increase the efficiency of the motor.
It is commonly known in the art to provide an air handling system such as a heating, ventilating or air conditioning ("HVAC") system with a blower or fluid pump that either pushes air over or draws air across a heat exchanger or cooling coil to heat or cool the air, respectively, and transfer the air through a system of ducts and vents to a room or rooms where a thermostat is located. The thermostat provides feedback to the system to indicate the temperature in the room or rooms. In this way, the temperature of the air in those rooms is controlled. The blower typically includes a motor and the HVAC system also usually includes a controller for controlling the motor in response to various parameters such as room air temperature, air flow rate, motor speed, and motor torque.
It is also known that the efficiency of the heat transfer between the air and the heat exchanger cooling coil is directly dependent upon the flow rate of air across the heat exchanger or the cooling coil. Moreover, it is known that the total system efficiency can be maximized by maintaining the flow rate of the air at a specific set point. The set point or flow rate at which the system is most efficient is often determined empirically (typically by the manufacturer of the HVAC system), and is programmed into the controller of the motor. As vents in the system are opened or closed, however, the load on the motor changes, thereby changing the motor speed, blower output and stator current. The changing loads experienced by the motor make precise control of the blower output extremely difficult. One method and apparatus for controlling a blower motor under such conditions is shown and described in U.S. Pat. No. 5,656,912, which is incorporated herein by reference.
SUMMARY OF THE INVENTION
In a variable speed induction motor, the current ("I") supplied to the motor includes both a flux generating component ("I flux ") and a torque generating component ("I torque "). In practice, I flux and I torque are about ninety degrees out-of-phase relative to one another. The actual torque ("T") output by the motor is determined by the relationship:
T=k[(I.sub.flux)x(I.sub.torque)];
where k is a known constant.
In prior art applications for variable speed induction motors (including the method and apparatus of U.S. Pat. No. 5,656,912), a flux output is generated that varies relative to the speed at which the motor is operating. However, at less than maximum motor load (for alternating current induction motors used in fluid pump or blower applications) there is a concomitant reduction in torque for the reduction in load. Thus, power is usually wasted because the motor is being supplied with current to generate flux that is in excess of what is necessary to generate the desired torque.
This phenomenon is clearly illustrated in FIGS. 6 and 7. FIG. 6 illustrates the torque and flux vector components of the motor current in the condition wherein the maximum output of the motor is demanded. Both the full flux and full torque components of the motor current are required. Hence, there are lower energy losses than at loads less than the maximum load capability of the motor.
FIG. 7 illustrates the torque and flux vector components of the motor current in a prior art controller. In the scenario of FIG. 7, the output required of the motor demands less than the maximum torque that the motor is capable of generating. However, because the amount of flux generated remains constant, energy losses result.
FIG. 8 illustrates the torque and flux vector components of the motor current of a motor connected to the controller of the present invention and in the condition wherein the output required of the motor demands less than the maximum torque that the motor is capable of generating. Where less than maximum output is required, the current supplied by the controller of the invention is manipulated to reduce the flux losses that result in controllers of the prior art.
Accordingly, the invention provides a method and apparatus for controlling a motor, and particularly, a method and apparatus for controlling an induction motor in an HVAC system to provide constant blower output control at an increased efficiency. Instead of the non-linear voltage-to-frequency relationship used in U.S. Pat. No. 5,656,912, the invention provides a controller for an induction motor that utilizes a linear voltage-to-frequency relationship and, for a given output requested by the thermostat, the controller curve fits the non-linear current feedback that is generated using the linear voltage-to-frequency relationship.
The invention further provides a controller for a motor having at least one stator phase, the controller comprising drive signal means for producing a current flow in the stator phase such that the current flow varies in response to varying load conditions for the motor; monitoring means for monitoring the current flow; change signal means for producing a change signal related to changes in the current flow; manipulation means electrically connected to the change signal means and to the drive signal means for changing the electrical drive signal in response to the change signal; and means for reducing the flux generated by the controller at any motor load that is less than the maximum load capability of the motor to thereby improve the operating efficiency of the motor.
The invention further provides a method for controlling a motor having at least one stator phase, the method comprising the steps of (A) producing an electrical drive signal in the stator phase resulting in a current flow in the stator phase; (B) determining a required motor load; and (C) reducing flux generated by the motor at required motor loads that are less than the maximum motor load capability.
It is a principal advantage of the invention to provide an efficient controller for any motor wherein the current has a known profile relative to the speed of the motor.
It is another advantage of the invention to provide a fluid pump for an HVAC system that provides substantially constant fluid flow or constant pressure irrespective of variations in the load on the fluid pump and at an extremely high efficiency.
It is another advantage of the invention to provide a controller for an induction motor which controller changes the voltage supplied to the motor in response to the total current supplied to the motor and output demanded by the controller.
It is another advantage of the invention to provide a method for controlling an induction motor in a fluid pump to provide a substantially constant fluid flow irrespective of load variations on the motor and at a high efficiency.
Other features and advantages of the invention are set forth in the detailed description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a motor controlled by a controller embodying the invention.
FIG. 2 is a graphical representation of the relationship between the stator current and the frequency of the electrical stimulus used to energize the motor.
FIG. 3 is a graphical representation of the linear relationship between the stator voltage and the frequency of the electrical stimulus that is used for a given desired air flow rate.
FIG. 4 is a graphical representation of the relationship between the desired fluid flow rate and the corresponding motor energization current.
FIG. 5 is a schematic diagram of a controller that is another embodiment of the invention.
FIG. 6 is a graphical vector representation of motor current at the maximum output or load of the motor shown in FIGS. 1 or 5.
FIG. 7 is a graphical vector representation of the motor current of prior art induction motors at less than maximum commanded output or load.
FIG. 8 is a graphical vector representation of the motor current of the motor of FIGS. 1 or 5 at less than maximum commanded output or load.
Before one embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of the construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Schematically illustrated in FIG. 1 of the drawings is a motor controller 10 and a motor 14. While the controller can be used to control any motor in any application, the motor of the preferred embodiment is a three phase induction motor employed in a fluid pump. More particularly, the fluid pump of the preferred embodiment is a blower for use in an HVAC system. As stated above, in HVAC systems, it has been shown that the efficiency of heat transfer between the heat exchanger or cooling coil and the air crossing over the heat exchanger or cooling coil is directly dependent upon the flow rate of the air passing across the heat exchanger or cooling coil. Moreover, it has been determined that the efficiency of the heat exchange is maximized at a specific air flow rate (usually determined by the design characteristics of the heating element or cooling coil).
The motor 14 includes a stator (not shown) having three phase windings, and a rotor (not shown) mounted for rotation about a rotor axis (also not shown). As is commonly known in the art, energization of the stator phases causes rotation of the rotor. The motor 14 also includes an arbor 18 connected to the rotor for rotation therewith. An impeller or blower fan 22 is mounted on the arbor 18 so that as the fan 22 rotates, air is drawn over or forced over the heat exchange unit (not shown) and from there is delivered to a system of ducts (not shown) for distributing the air to a room or rooms. A series of switches 26 selectively electrically connect the motor 14 to electrical power (typically direct current derived from standard alternating current line voltage) in response to control signals produced by the controller 10.
The controller 10 includes a thermostat 30 that is located within the room or rooms to be heated or cooled. The thermostat 30 monitors the room air temperature and generates, in response to the room air temperature, control signals for initiating operation of the motor 14.
The controller 10 also includes a microprocessor 34 connected to the thermostat 30 to receive therefrom the thermostat control signals. The microprocessor 34 is also connected to the switches 26 supplying power to the motor 14. The microprocessor 34 controls the switches 26 to energize the motor 14 so that the fan 22 delivers a constant flow rate volume of air despite any change in the load conditions experienced by the motor 14. Typically, such load changes occur as vents in the duct system are opened or closed. AS is commonly known in the art, a series of drivers 38 are connected between the power switches 26 and the microprocessor 34.
The microprocessor 34 includes a decoder 42 for receiving the thermostat control signals and generating in response thereto a desired air flow rate signal ("CFM d "). The microprocessor 34 also includes drive signal means or energizing means connected to the decoder 42 for producing an electrical drive signal or electrical stimulus resulting in current flow in the stator phase. While various means for producing the electrical drive signal are appropriate, the drive signal means of the preferred embodiment includes a current frequency converter 46 connected to the decoder 42 and a current command calculator 50 connected to the current frequency converter 46.
The microprocessor also includes change signal means for producing a change signal related to changes in stator current flow. While various means for generating the change signal are appropriate, in the preferred embodiment the change signal means includes a comparator 54 connected to the current command calculator 50.
The microprocessor also includes manipulation means connected to the comparator and to the drive signal means for changing the electrical drive signal in response to the output from the comparator 54. While various means for changing the electrical drive signal are appropriate, the manipulation means of the preferred embodiment includes a current regulator or integrator 58 connected to the comparator 54 and a summation node 62 connected to the current regulator 58.
The summation node 62 has an output which is fed back through a delay element 66 to an input of the summation node 62 and to the current command calculator 50. The output of summation node 62 is also connected to a frequency-to-voltage calculator 70. The frequency-to-voltage calculator 70 includes an input connected to the output of decoder 42 to receive the CFM d signal from decoder 42. A pulse width modulator 72 is connected to the frequency-to-voltage calculator 70. The pulse width modulator 72 is connected to the switch drivers 38 to output signals thereto and selectively connect the phases of the motor 14 to electrical power.
The controller 10 also includes monitoring means for monitoring the current flow in the stator phase. Any known means for monitoring or measuring the stator current is appropriate. In the embodiment shown in FIG. 1, the monitoring means is a current sensor 74 connected to at least one of the motor phases to detect motor phase current.
In operation, the microprocessor 34 controls the motor 14 using the relationship between stator current, stator frequency and air flow rate shown in FIG. 2. This relationship has been empirically determined and, as clearly shown in FIG. 2, for a given air flow rate, the stator current versus the stator frequency relationship is generally non-linear, and can be defined by the non-linear equation:
y=ax.sup.2 +(mx+b); where
y=desired stator command current for the present time period (I);
a=a curve fitting constant;
x=stator command frequency for previous time period (ω 1 );
m=slope of current frequency curve (the slope is determined by the blower characteristics, for example, cage size, number of blades, etc.); and
b=the zero frequency or steady state no-load stator current (I 2 ).
By knowing the desired air flow rate at which the HVAC system is to operate, the zero frequency stator current I 2 at that air flow rate and the stator command frequency ω 1 for the previous time period, the microprocessor 34 can easily calculate the desired A stator command current I at which the motor 14 must be energized to generate the desired air flow rate output. If the desired stator command current I differs from the actual stator current I 1 , then the stator command frequency ω 1 can be adjusted to compensate for the difference, which is assumed to be the result of a change in the load on the motor 14. In a broad sense, the controller can be used to control any motor where the relationship between the electrical signal used to energize the motor and the output of the motor is known.
More specifically, and referring to FIG. 1, the decoder 42 receives the thermostat inputs and generates in response to the thermostat inputs an output that is indicative of a desired cubic feet per minute flow output (CFM d ) for the motor blower. The current frequency converter 46 receives the CFM d signal and generates in response to the CFM d signal the zero frequency stator current value (I 2 ). The current frequency converter 46 can generate I 2 using a real time calculation, however, in the preferred embodiment, the current frequency converter 46 is simply a memory based look-up table that stores zero frequency stator current values for a number of different flow rates. The relationship between CFM d and I 2 is shown in FIG. 4. The current frequency converter 46 transmits the zero frequency stator current to the current command calculator 50.
At approximately the same time, the command frequency ω 1 , i.e., the command frequency from the previous 0.6 second time period, is fed back to the current command calculator 50 from the output of the summation node 62. In response to receipt of the zero frequency stator current I 2 and the command frequency signal ω 1 , the current command calculator 50 generates a command current I, i.e., the current at which the motor 14 should be energized for a given blower output. As stated above, the relationship used for this determination is shown in FIG. 2.
The command current I is fed to the comparator 54 and compared against the actual phase current I 1 as measured by the current sensor 74. The current comparator 54 outputs a current error value (ΔI) that represents the difference between the actual stator phase current I 1 and the desired stator phase current I 2 for the desired air flow rate CFM d .
The current error (ΔI) is transmitted to current regulator 58 which integrates the current error signal ΔI to generate a manipulation output (Δω). The manipulation output Δω is added to the previous command frequency ω 1 to generate an updated command frequency ω 2 . The updated command frequency 107 2 represents an updated frequency signal which is required at existing motor current I 1 to maintain the desired blower air flow rate output CFM d . The command frequency ω 2 is transmitted to the frequency-to-voltage calculator 70 which generates an updated command voltage. The frequency-to-voltage calculator 70 uses the relationship shown in FIG. 3 to generate the command voltage and this voltage is input to the pulse width modulator 72 along with the updated command frequency. While the voltage-to-frequency relationship shown in U.S. Pat. No. 5,656,912 was non-linear, the voltage-to-frequency relationship of the preferred embodiment is linear for a given CFM d . The function performed by the frequency-to-voltage calculator 70 is performed using a real time software based calculation based on the equation:
V=K.sub.f ω.sub.2 ;
where V is the updated command voltage, K f is a flux constant to convert the frequency units to voltage units as a function of CFM d , and ω 2 is the command frequency for the stator. The linear relationship between the updated command voltage (V) and the command frequency (ω 2 ) for a given CFM d is shown in FIG. 3. By using a linear voltage-to-frequency relationship and curve fitting the non-linear current feedback, the slope of the voltage-to-frequency curve, i.e., the flux, is adjusted for the various CFM d that is commanded.
In other embodiments (not shown), the results of the function may be precalculated and, like the functions of the current frequency converter 46 and the current command calculator 50, the frequency-to-voltage converter function may be stored in a memory based look-up table. The command frequency (ω 2 ) is also fed back to the current command calculator 50 through the delay element 66 which causes a transmission delay of approximately 0.6 seconds. This period of delay is to account for the fact that the load in the HVAC system changes slowly as the vents are opened or closed and the delay prevents instability of the controller.
In response to the updated command frequency ω 2 and the updated command voltage V, the pulse width modulator 72 generates control signals for the drivers 38 which operate the switches 26 to generate an updated current output for the motor 14 to maintain the desired air flow rate output. The current sensor 74 will continue to measure the stator phase current. If the blower motor load remains the same from one 0.6 second interval to the next, then the stator phase current I, will not change, and there will be no resulting current error signal ΔI generated. As a result, the command frequency ω 2 output at the summation node 62 will not change. Alternatively, if the blower motor load changes from one 0.6 second interval to the next, then a new current error signal ΔI will be generated to cause a recalculation of the command frequency ω 2 as described above.
FIG. 5 illustrates a controller 100 that is an alternative embodiment of the invention. Like parts are identified using like reference numerals. In the embodiment shown in FIG. 5, the current and voltage from the d.c. bus, I dcbus and V dcbus are measured and input to a current calculator 104 along with the command voltage (V) generated by the voltage-to-frequency calculator 70. These parameters are used to calculate an approximated phase current (I phase ) that is input to the comparator 54. The equation used to generate (I phase ) is;
I.sub.phase cos θ=(V.sub.dcbus xI.sub.dcbus)/V.
The use of the current calculator 104 to calculate an approximate phase current eliminates the need for an expensive phase current sensor. Moreover, calculating the estimated phase current from the d.c. bus current and voltage eliminates error that may result from measuring current that is recirculating between the inverter and the phase winding of the motor.
Various features and advantages of the invention are set forth in the following claims: | A method and apparatus for improving the efficiency of an induction motor used in fluid pump and blower applications including a controller that reduces the flux generated by the motor at less than maximum motor loads. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to novel thermosettable cyanate ester resins and to triazines derived therefrom.
Cyanate esters are a class of thermosettable materials of interest in electronics applications because of their ease of processing, low dielectric constant and high glass transition temperature. Aromatic cyanate esters comprising dicyclopentadiene linking moieties are known to cure to triazine resins having high Tg and low moisture absorbance. For high-performance electronic applications, thermosettable resins having increasingly low melt viscosity (for ease and speed of processing) and low water absorbance in the cured state are required.
It is therefore an object of the invention to provide novel cyanate esters having low melt viscosity and low water absorbance in the cured state.
SUMMARY OF THE INVENTION
According to the invention, a cyanate-functional compound is provided which can be described by the formula ##STR2## in which Ar is a C 6-20 aromatic moiety, L is a cyclohexanenorbornane linking moiety, L' is a divalent cycloaliphatic moiety, and each of m and n is a number within the range of 0 to about 10. Such cyanate esters include the product of cyanation of the addition reaction of a phenol and a cyclohexene-norbornene compound such as 5-(3-cyclohexen-1-yl)-bicyclo[2.2.1]hept-2-ene. Such cyanate esters are useful as the resinous component of electrical laminating and encapsulation formulations.
DETAILED DESCRIPTION OF THE INVENTION
The invention cyanate esters can be prepared by reacting the precursor polyphenols (described below) with a cyanogen halide such as cyanogen chloride or cyanogen bromide in the presence of a basic catalyst. The reaction can be carried out at a temperature within the range of about -15° C. to about 60° C., preferably about 0° to about 20° C. Suitable catalysts include alkali metal hydroxides such as sodium hydroxide or potassium hydroxide; alkali metal alkylates such as sodium methylate or potassium methylate; and tertiary amines such as trimethyl amine, triethyl amine, methyl diethyl amine, tripropyl amine, tributyl amine, dimethyl cyclohexyl amine and diethyl aniline. The preferred basic catalyst is triethylamine. The basic catalyst is generally present in the reaction mixture in an amount of at least about 1 mole, preferably about 0.8 to about 1.2 moles, per mole of the cyanogen halide. The cyanogen halide is generally present in an amount within the range of about 0.8 to about 1.5 moles per phenolic hydroxyl group.
The precursor polyphenols can be described by the formula ##STR3## in which Ar is a C 6-20 aromatic moiety, L is a divalent cyclohexanenorbornane moiety, L' is a divalent cycloaliphatic moiety, and each of m and n is a number within the range of 0 to about 10. Such polyphenols can be prepared by the addition reaction of a phenol with a cyclohexenenorbornene compound such as 5-(3-cyclohexen-1-yl)bicyclo[2.2.1]hept-2-ene (herein referred to as the "cyclohexenenorbornene" compound). Suitable phenols include mono- and polynuclear phenols having at least one unsubstituted position ortho- or para- to a phenolic hydroxyl group, such as phenol, cresol, 3,4- and 3,5-dimethylphenol, resorcinol, biphenol, 1-naphthol and bisphenol A or F. Phenol is preferred.
Suitable cyclohexenenorbornene compounds include ##STR4## referred to herein as "monoadduct," "diadduct" and "triadduct," respectively, and isomers thereof.
The starting phenol can also include a derivative L' of a cycloaliphatic diene such as dicyclopentadiene, cyclopentadiene, norbornadiene dimer, norbornadiene, methylcyclopentadiene dimer, limonene, 1,3- and 1,5-cyclooctadiene, α- and γ-terpinene, 5-vinylnorbornene, 5-(3-propenyl)-2-norbornene, and cyclopentadiene oligomers for example. The preparation of such a phenol is illustrated in Example 6 herein.
The cyclohexenenorbornene starting material is an addition product of 4-vinylcyclohexene and cyclopentadiene which can be prepared by contacting 4-vinylcyclohexene and dicyclopentadiene, preferably in the presence of a polymerization inhibitor such as t-butyl catechol, at a temperature of at least about 150° C., preferably about 180° C. to 260° C., for a time within the range of about 2 hours to about 8 hours. Under these conditions, the dicyclopentadiene is cracked to cyclopentadiene, and the vinylcyclohexene and cyclopentadiene undergo an addition reaction to produce a mixture of mono-, di- and poly-adducts as well as cyclopentadiene oligomers (e.g., trimer, tetramer, pentamer, etc.). For recovery of one or more desired compounds, the reaction product mixture containing predominantly 5-(3-cyclohexen-1-yl)bicyclo[2.2.1]hept-2-ene (monoadduct) is allowed to cool to about 50°-70° C. and is stirred under reduced pressure to strip off unreacted vinylcyclohexene. The reaction product is then purified by fractional vacuum distillation for removal of by-products including, optionally, di- and polyadducts, and the purified product is passed through an adsorbent bed for removal of t-butyl catechol. Preparation of a vinylcyclohexene/cyclopentadiene adduct is illustrated in Example 1 herein.
The phenolic precursors of the invention cyanate esters can be prepared by contacting, under addition reaction conditions, the above-described vinylcyclohexene/cyclopentadiene adduct with a molar excess, preferably about 10 to about 30 moles, of the selected phenol per mole of the adduct. The reaction is most efficiently carried out in the presence of a Lewis acid such as BF 3 , coordination complexes thereof such as boron trifluoride etherate, AlCl 3 , FeCl 3 , SnCl 4 , ZnCl 2 , silica and silica-alumina complexes and at an elevated temperature within the range of about 70° to about 200° C., preferably about 100° to about 180° C. The reaction is continued until the desired degree of reaction has been completed, usually for a time within the range of about 30 minutes to about 10 hours, preferably about 1 hour to about 3 hours. Preparation of such polyphenols is illustrated in Examples 2, 4 and 6 herein. Cyanation of the resulting polyphenols to prepare the invention cyanate esters is described above and in Examples 3, 5 and 7 herein.
The invention cyanate-functional compounds are cured by exposure to elevated temperature of at least 150° C., generally within the range of about 150° to about 250° C., for a time which can vary widely depending upon the cure schedule and the thickness of the part, generally greater than about 0.25 hour. Optimum properties in the cured resin can be achieved by a staged heating process employing higher temperature in each stage, as illustrated in the Examples below. The cyanate esters can be co-cured with other cyanate ester compounds and/or with other thermosettable resins such as bismaleimide resins and epoxy resins.
The invention cyanate esters are useful in preparing electrical laminates and in molding compounds.
EXAMPLE 1
Preparation of 5-(3-cyclohexen-1-yl )bicyclo[2.2.1]hept-2-ene
Dicyclopentadiene and 4-vinylcyclohexene in equimolar mixture were heated in an autoclave at 240° C. for 4-4.5 hours. The reaction product was diluted with cyclohexane and passed through a packed bed of alumina to remove the t-butylcatechol inhibitor introduced with the reactants. The resulting product mixture was distilled in a wiped film evaporator at 3 mm Hg pressure at 90° C. to produce a light fraction containing unreacted vinylcyclohexene and dicyclopentadiene and the mono-adducts of 4-vinylcyclohexene and cyclopentadiene. A 150 g sample of this distillate was vacuum distilled using a 10-tray Oldershaw column to give four fractions. The fourth fraction, 65 g, was shown by gas chromatographic analysis to consist of 0.15% dicyclopentadiene, 88.3% endo-5-(3-cyclohexen-1-yl)-2-norbornene, 6.1% exo-5-(3-cyclohexen-1-yl)-2-norbornene and two additional components present in the amount of 1.9% and 2.4% which are believed to be isomeric adducts of the formula ##STR5## several additional components totalling about 0.4%, 0.4% tricyclopentadiene and about 0.4% unidentified components. Analysis of the fraction by nuclear magnetic resonance indicated about 87 mole percent of the endo adduct, about 9 mole percent of the exo adduct and about 5% of the isomeric adducts.
EXAMPLE 2
Preparation of Precursor Polyphenol A.
To a reactor equipped with a stirrer, condensor and addition funnel were added 188.2 g (2.0 mole) of phenol and 1.0 g of BF 3 .Et 2 O catalyst. The mixture was heated to 70° C. and 13.67 g of 5-(3-cyclohexen-1-yl)bicyclo[2.2.1]hept-2-ene was added over a 20-minute period. The temperature was raised to 150° C. over a 11/2-hour period and was held for about 21/2 hours. Unreacted phenol was distilled off. The recovered polyphenol had a terminal hydroxyl group concentration of 0.495 equivalent/100 g and a melting point of 70°-80° C.
EXAMPLE 3
Preparation and Curing of Cyanate Resin.
In 450 ml of chloroform were dissolved 20.65 g (0.195 mole) of cyanogen bromide and 33.55 g (0.195 mole) of polyphenol A derived from the addition reaction of phenol and 5-(3-cyclohexen-1-yl)bicyclo[2.2.1]hept-2-ene. The resulting solution was ice-cooled. Triethylamine (20.72g, 0.20 mole) was stirred into the solution over a period of 60 minutes, during which the reaction temperature was maintained at 5°-10° C. After the reaction was complete, the chloroform solution was washed several times with H 2 O and removed under reduced pressure to give 31.86 g of an amber viscous liquid. IR analysis of the product gave a characteristic absorption band of a cyanic acid ester group at 2250 cm -1 . The product can be represented structurally as ##STR6##
The cyanate acid ester was cured at 200° C. for 2 hours, 220° C. for 2 hours, and 240° C. for 4 hours to provide a cured product having a Tg of 190° C., heat decomposition temperature of 450° C. and water gain of 1.0% (2 weeks 93° C.). Mechanical and electrical properties are shown in Table 1.
EXAMPLE 4
Preparation of Polyphenol Precursor B
To a reactor equipped with a stirrer, condensor and addition funnel were added 376 g (4.0 mole) of phenol and 2.0 g of BF 3 .Et 2 O. The reaction mixture was heated to 70° C., and 48 g (0.2 mole) of diadduct was added over a 20-minute period. The temperature was raised to 150° C. over a 11/2-hour period and held for about 21/2 hours. Unreacted phenol was distilled. The recovered product melted over the range of 85°-95° C. and had a phenolic hydroxyl content of 0.47 eq/100 g.
EXAMPLE 5
Preparation and Cure of Cyanate Resin
The procedure described in Example 3 was repeated starting with 50.0 g of polyphenol B, 24.91 g (0.235 mole) cyanogen bromide and 23.78 g (0.235 mole) of triethylamine. 57.7 g of a glassy solid having a melting point of 45°-55° C. was isolated. The product can be represented structurally as ##STR7##
The product was cured by heating at 200° C. for 2 hours, 220° C. for 2 hours and 240° C. for 4 hours to provide a cured solid having a Tg of 221° C., a heat decomposition temperature of 450° C. and water gain of 1.02% (2 weeks 93° C.). Mechanical and electrical properties are shown in Table 1.
EXAMPLE 6
Preparation of Precursor Polyphenol C
To a reactor equipped with a stirrer, condensor and addition funnel, 295.7 g (3.14 mole) of phenol and 2.0 g of BF 3 .Et 2 O were added. The mixture was heated to 70° C., and 13.67 g (0.07856 mole) of 5-(3-cyclohexen-1-yl) bicyclo[2.2.1]hept-2-ene and 10.29 g (0.07856 mole) of dicyclopentadiene were added over a 20-minute period. The temperature was raised to 150° C. over a 11/2-hour time period and was held for 21/2 hours. Unreacted phenol was distilled off. The recovered polyphenol melted over the range of 70°-78° C.
EXAMPLE 7
Preparation and Cure of Cyanate Resin
The procedure described in Example 3 was repeated starting with 50.03 g (0.291 mole) of polyphenol C, 30.82 g (0.291 mole) of cyanogen bromide and 30.86 g (0.305 mole) of triethylamine. 59.4 g of cyanate resin was isolated as a heavy oil. The product includes the structural units ##STR8##
Curing of the product cyanate-functional material at 200° C. for 2 hours, 220° C. for 2 hours and 240° C. for 4 hours gave a cured product having a Tg of 180° C. and a heat decomposition temperature of 450° C.
EXAMPLE 8
Preparation of Precursor Polyphenol D (Comparison)
To a reactor equipped with a stirrer, condensor and addition funnel were added 188.2 g (2.0 mole) of phenol and 1.0 g of BF 3 .Et 2 O. The reaction mixture was heated to 70° C., and 13.2 g (0.1 mole) of dicyclopentadiene were added over a 20-minute period and held for 21/2 hours. Unreacted phenol was distilled. The recovered product had a melting range of 115°-120° C. and a phenolic hydroxyl content of 0.62 eq/100 g.
EXAMPLE 9
Preparation and Cure of Cyanate Resin (Comparison)
The procedure described in Example 3 was repeated starting with 100 g (0.62 mole) of polyphenol D, 65.7 g (0.62 mole) of cyanogen bromide and 62.74 g (0.62 mole) of triethylamine. 93 g of cyanate resin was isolated as a semisolid. The product can be represented structurally as ##STR9##
The product was cured by heating at 200° C. for 2 hours, at 220° C. for 2 hours and at 240° C. for 4 hours, to produce a product having a Tg of 218° C. (DSC) and 250° C. (DMA, Tan delta) and a heat decomposition temperature of 450° C. The mechanical and electrical properties are shown in Table 1 for comparison.
TABLE 1______________________________________Neat Resin Properties of Cyanate Resins Ex. 3 Ex. 5 Ex. 9______________________________________Tg (DSC) 190 221 218Flexural properties (RT/Dry)Strength (ksi) 13.4 10.7 16.9Modulus (ksi) 540 508 532Elongation (%) 2.5% 2.11% 3.2%Flexural properties (Hot/Wet)Strength (ksi) 8.0 5.34 8.9Modulus (ksi) 440 477 485Elongation (%) 1.9% 1.00% 1.86%Modulus retention (%) 82 94 91Fracture toughness (Kq) 916 503 468Moisture gain (%) 1.1% 1.02% 1.5%Dielectric constant at 1 MHz 2.65 2.73 2.89______________________________________
Cure of Cyanate Resin with Bismaleimide Resin
The cyanate resin prepared in Example 3 (12.72 g) was melt-blended with Compimide® MDAB bismaleimide (6.36 g) at 120°-130° C. The mixture was heated in an oven at 200° C. for 2 hours, at 220° C. for 2 hours and at 240° C. for 4 hours. The resulting cured product had a Tg of 182° C. and a heat decomposition temperature of 450° C.
EXAMPLE 10
Cure of Cyanate Resin with Bismaleimide Resin
The cyanate resin prepared in Example 5 (27.0 g) was melt-blended with Compimide® MDAB bismaleimide (3 g) at 120°-130° C. The mixture was then heated in an oven at 200° C. for 2 hours, at 220° C. for 2 hours and at 240° C. for 4 hours. The resulting cured material had a Tg of 223° C., water gain of 1.29% (2 weeks, 93° C.) and dielectric constant of 2.81 at 1 mHz. | A cyanate-functional compound is provided which can be described by the formula ##STR1## in which Ar is a C 6-20 aromatic moiety, L is a hexanenorbornane linking moiety, L' is a divalent cycloaliphatic moiety, and each of m and n is a number within the range of 0 to about 10. Such cyanate esters include the product of cyanation of the addition reaction of a phenol with a cyclohexene norbornene compound such as 5-(3-cyclohexen-1-yl)bicyclo[2.2.1]hept-2-ene. The resulting cyanate esters have low melt viscosity and low water absorbance in the cured state and are useful as the resinous component of high-performance electrical laminating and encapsulation formulations. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to slurry concentrates used in the fracturing of oil, gas, and geothermal wells. The slurry concentrates are useful fur shale gas fracturing operations. More particularly, the invention relates to slurry concentrates containing a viscosity-enhancing polymer and organic-functionalized hectorite clay.
BACKGROUND OF THE INVENTION
[0002] Fracturing fluids are employed in oil and gas drilling operations, including shale gas and oil fracturing (“fracking”) operations, Several types of fracturing fluids are used in the oil, gas, and geothermal well drilling operations. Water-based fracturing is commonly performed using “slick water”. T. T. Palisch, M. C. Vincent, P. J. Flandren, SPE Production & Operations, 25, 327-344, 2010. Another method used in the industry is known as “dry on fly” fluid fracturing. A third method used in the industry makes use of oil-based fracturing fluids. A fourth type of fracturing fluid may be prepared using a slurry of a viscosity-enhancing polymer.
[0003] Slurry concentrates known in the prior art and based on organoclays, such as bentonite, contain 2-3% crystalline silica, which presents a safety hazard to the workers handling such additives. A desirable slurry concentrate would contain minimal to no crystalline silica and could be handled by workers with less risk of personal harm.
SUMMARY OF THE INVENTION
[0004] A method to improve the stability of a slurry concentrate. A viscosity enhancing polymer, a hectorite organoclay composition and an aliphatic hydrocarbon carrier fluid are combined. The viscosity enhancing polymer is selected from glactomannan gums, guars, derivatized guars, cellulose and cellulose derivatives, starch, starch derivatives, xanthan, derivatized xanthan and mixtures thereof. The hectorite organoclay composition comprises (i) hectorite clay having a cation exchange capacity of at least 110 milliequivalents per 100 grams of clay, 100% active clay basis and (ii) a quaternary ammonium salt having formula (I):
[0000]
[0000] wherein R 1 and R2 are methyl, R 3 is methyl or a linear alkyl group having from 14 to 18 carbon atoms and R 4 is a linear alkyl group having from 14 to 18 carbon atoms, and where X− is an anion, wherein the total amount of quaternary ammonium cation is provided in an amount from about +25% to −25% of the cation exchange capacity of the hectorite clay. The slurry concentrate exhibits a 300 rpm viscosity of less than 300 cP at 40° F. and a syneresis of less than 1% after 72 hours at 70° F. In some embodiments, the slurry concentrate further exhibits a 300 rpm viscosity of less than 120 cP at 70° F. and a syneresis of less than 2.5% after 24 hours at 100° F. In some embodiments, the viscosity enhancing polymer is guar.
[0005] In some embodiments, the amount of viscosity enhancing polymer is between about 40 weight % and 60 weight %. In some embodiments, the amount of hectorite organoclay is between about 1.0 weight % and 3.0 weight %.
[0006] In some embodiments, R 1 , R 2 , and R 3 are methyl and R 4 is a linear alkyl group having from 14 to 18 carbon atoms. In some embodiments, the quaternary ammonium cation is methyl tris[hydrogenated alkyl] ammonium cation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The foregoing summary, as well as the following detailed description of embodiments of the method of the present invention, will be better understood when read in conjunction with the appended drawings of exemplary embodiments. In the drawings:
[0008] FIG. 1 shows pug-milted hectorite concentration in a slurry formulation versus 300 rpm viscosity at 40° F. Viscosity values are given in units of centipoise (cP),
[0009] FIG. 2 shows pug-milled hectorite concentration in a slurry formulation versus % syneresis at 100° F.
[0010] FIG. 3 shows wet processed hectorite concentration in a slurry formulation versus 300 rpm viscosity at 40° F. Viscosity values are given in units of cP.
[0011] FIG. 4 shows wet processed hectorite concentration in a slurry formulation versus % syneresis at 100° F.
[0012] FIG. 5 shows a comparison of the 300 rpm viscosity results in a slurry formulation obtained at 40° F., in units of cP, for slurry concentrates prepared using a different organoclay.
[0013] FIG. 6 shows a comparison of the % syneresis for a slurry formulations prepared using a different organoclay.
DETAILED DESCRIPTION OF THE INVENTION
[0014] In the practice of the present invention, a slurry concentrate is prepared comprising a viscosity enhancing polymer selected from the group consisting of: galactomannan gums, guars, derivatized. guars, cellulose and cellulose derivatives, starch, starch derivatives, xanthan, derivatized xanthan and mixtures thereof; a hectorite organoclay composition, wherein the hectorite organoclay composition comprises (i) a hectorite clay having a cation exchange capacity of at least 110 milliequivalents per 100 grams of clay, 100% active clay basis and (ii) a quaternary ammonium cation having the formula (1):
[0000]
[0015] wherein R 1 and R 2 are methyl, R 3 is methyl or a linear alkyl group having from 14 to 18 carbon atoms and R 4 is a linear alkyl group having from 14 to 18 carbon atoms, wherein the total amount of quaternary ammonium cation is provided in an amount from about +25% to −25% of the cation exchange capacity of the hectorite clay; and an aliphatic hydrocarbon carrier fluid.
[0016] Viscosity Enhancing Polymers
[0017] Viscosity enhancing polymers include galactomannan gums, guars, derivatized guars, cellulose and cellulose derivatives, starch, starch derivatives, xanthan, derivatized xanthan and mixtures thereof. The polymers include natural galactomannan gums, which are complex oligosaccharides that contain a backbone of mannose units with galactose units attached to the mannose backbone, and their derivatives and modifications. The galactomannan gums and their derivatives and modifications may contain attached hydroxyl, carboxyl, sulfate, sulfonate, amino, or amide functional groups. Natural galactomannans can include guar gum, locust bean gum, tara and other gums derived from endosperm seeds, and other gums. Galactomarman derivatives include hydroxyalkyl galactomannans, carboxyalkyl galactomannans, and hydroxyalkyl carboxyalkyl galactomannans. The use of guar, guar derivatives, and related polymers and oligomers as additives for fracturing fluids is further described in U.S. Pat. Nos. 3,081,260, 4,487,867, 5,165,479, 5,439,059, 6,387,853, and 7,790,774, which are incorporated by reference herein in their entirety. Guar is a complex oligosaccharide obtained from natural sources. Guar consists of branched chains of galactose and mannose sugars. Guar is currently widely used as an additive in fracturing fluids. Guar can be derivatized to improve its temperature stability in fracturing applications. The guar and derivatized guar products used as fracturing fluid additives can be powders or dispersions of powders in non-aqueous suspensions.
[0018] Organoclay
[0019] Hectorite is a magnesium-lithium silicate clay in the smectite family. Hectorite possesses a layered structure. To render it suitable for a slurry concentrate, hectorite and other smectite clays can be cation-exchanged to replace lithium and magnesium with other cations that lead to increases in the spacing between the silicate layers. Functionalized hectorite clays can be prepared using branched-chain quaternary ammonium salts as reactants as described in U.S. Pat. Nos. 2,966,506, 4,081,496, 4,105,578, 4,116,866, 4,208,218, 4,391,637, 4,410,364, 4,412,018, 4,434,075, 4,424,076, 4,450,095, 4,517,112, and 5,739,087, which are incorporated herein by reference. Functionalized hectorite clays are also referred to as “organoclays.” The process to produce an organoclay involves the ion exchange of magnesium and lithium ions for the branched or linear-chain quaternary ammonium ions, resulting in the formation of expanded layers within the clay.
[0020] Hectorite organoclay compositions include hectorite and quaternary ammonium cations of formula (I). Functionalized hectorite organoclays can be prepared using branched or linear-chain quaternary ammonium salts as reactants as described in U.S. Pat. Nos. 2,966,506, 4,081,496, 4,105,578, 4,116,866, 4,208,218, 4,391,637, 4,410,364, 4,412,018, 4,434,075, 4,424,076, 4,450,095, 4,517 112, and 5,739,087, which are incorporated herein by reference. The process to produce an organoclay involves the ion exchange of magnesium and lithium ions tier the branched or linear-chain quaternary ammonium ions, resulting in the formation of expanded layers within the clay.
[0021] In some embodiments, the quaternary ammonium cation of formula (I) has R 1 , R 2 , and R 3 are methyl and R 4 is a linear alkyl group having from 14 to 18 carbon atoms. In some embodiments, the quaternary ammonium ion includes trimethyl hydrogenated tallow ammonium salt, also known as 3MHT. In other embodiments, the quaternary ammonium ion also includes dimethyl dihydrogenated tallow quaternary ammonium salts (2 M 2 HT).
[0022] Generally, the viscosity enhancing polymer in the slurry concentrate is present at about 40 weight % to 60 weight %. More preferably, the viscosity enhancing polymer in the slurry concentrate is present at about 45 weight % to 50 weight %. Most preferably, the viscosity enhancing polymer in the slurry concentrate is present at about 47 weight %.
[0023] Generally, the organoclay in the slurry concentrate is present at about 1 weight % to 3 weight %. More preferably, the organoclay in the slurry concentrate is present at about 1.5 to 2.5 weight %. Most preferably, the organoclay is present at about 1.8 weight % to 2.2% weight %.
[0024] Measurements of the viscosity of a slurry concentrate provide a means of assessing the suspension characteristics of the concentrate. It does impact the homogeneity of the polymer delivery system. The viscosity has to be low enough to be able to pump the slurry at low temperatures (e.g., 40° F.) and high enough to suspend the polymer in oil at storage conditions (e.g., 100° F.), Homogeneity will impact the ability to deliver polymers such as guar to the annulus. Slurries do not impact the viscosity of the fluid in the annulus
[0025] Determination of syneresis provides an indication of the homogeneity of the slurry concentrate. Syneresis is defined as the loss of homogeneity that occurs in a slurry when contraction of a gel leads to the expulsion of liquid. As used herein, lower syneresis values generally correlate with a more homogeneous slurry concentrate and a more effective delivery of the slurry concentrate to the annulus which improves the fracturing fluids performance.
[0026] The invention is further described by the following non-limiting examples, which illustrate the surprising superiority of the slurry concentrate.
EXAMPLES
[0027] Slurry concentrates as described below were formulated and tested for functional and theological properties. Two batches were prepared for each screened additive. Samples of each slurry concentrate were used to fill 100 mL glass graduated cylinders for static aging observation at ambient temperature, 40° F., and 100° F. The remaining portion of each slurry concentrate was equally distributed into three 16 ounce glass jars that were stored at ambient temperature, 40° F., and 100° F. The viscosity at 300 revolutions per minute (“rpm”) of each jarred sample was measured using an OFI-800 viscometer (OFI Testing Equipment, Houston, Tex.). Measurements were performed following the procedures described in API RP 13B.
[0028] Syneresis was determined using the following procedure. After a determined time interval, a visual measurement of clear liquid on the top of a 100 ml graduate cylinder filled with slurry concentrate was taken and reported as % syneresis. Since a 100 ml graduate was used, 1 ml of syneresis is equivalent to 1%.
Example 1
[0029] Example 1 illustrates the results obtained from a slurry concentrate prepared according to the present invention. The organoclays were prepared by first placing 85.7 g of 3 MHT in an oven at 65° C. At the same time, 107.9 g of hectorite clay was placed in a bakers tray and warmed in the oven. When the 3 MHT became molten, the 3 MHT and clay were both removed from the oven and the amine was poured onto the clay. The resulting organoclay was hand dispersed with a spatula for 5 minutes. The organoclay was then ground through a hand-turned meat grinder (3 passes). This ground organoclay was then dried in a forced hot air oven at 105° C. for approximately 16 hrs. The dried organoclay was milled using a Brinkman mill (0.5 micron mesh screen, 1 pass). The milled, dried organoclay was used to prepare guar slurries.
[0030] Guar slurries were prepared by charging materials to a 1 L stainless steel beaker using an overhead stirring motor equipped with a 4-paddle, 2.5 cm×1.0 cm stirring blade using the following procedure, which was repeated for each level of organoclay used. EcoNo 818 mineral oil solvent (313.2 g,) was charged to the beaker. The organoclay was then charged at levels of 1.8%, 2.0%, or 2.2% by weight and the mixture was stirred for 5 min at 1000 rpm. Propylene carbonate (4.4 g) was then charged and the mixture was stirred for 5 min at 1250 rpm. Guar (287.4 g) was then added and the mixture was stirred at 1300 to 1500 rpm for 10 min. Tergitol (2.6 g) was then added, and the combined mixture was stirred for 10 min at 1600 to 1800 rpm.
[0031] The results of viscosity measurements at 300 rpm and 40° F. are shown in FIG. 1 . The results of syneresis measurements at 100° F. are shown in FIG. 2 .
Example 2
[0032] Example 2 illustrates the results obtained from a slurry concentrate prepared according to the present invention. The organoclays were prepared by first placing 85.7 g of 3 MHT in an oven at 65° C. At the same time, 107.9 g hectorite clay was added to tap water in a stainless steel reactor, using sufficient tap water to produce a slurry containing 5% by weight of hectorite clay. The stainless steel reactor was equipped with an overhead stirrer and thermal controller. The slurry was warmed to 65° C. When the 3 MHT became molten and the slurry reached temperature, the 3 MHT was charged to the hectorite clay slurry and mixed for 1 hour in the stainless steel reactor. After 1 hour, the organoclay mixture was filtered. The collected organoclay was dried for approximately 16 hours in a forced hot air oven at 105° C. The dried organoclay was milled using a Brinkman mill (0.5 micron mesh screen, 1 pass). The milled, dried organoclay was used to prepare guar slurries.
[0033] Slurry concentrates were prepared by charging materials to a 1 L stainless steel beaker using an overhead stirring motor equipped with a 4-paddle, 2.5 cm×1.0 cm stirring blade using the following procedure, which was repeated for each level of organoclay used. EcoNo 818 mineral oil solvent (313.2 g,) was charged to the beaker. The organoclay was then charged at levels of 1.8%, 2.0%, or 2.2% weight and the mixture was stirred for 5 min at 1000 rpm, Propylene carbonate (4.4 g) was then charged and the mixture was stirred for 5 min at 1250 rpm. Guar (287.4 g) was then added and the mixture was stirred at 1300 to 1500 rpm for 10 min. Tergitol 15S9 (2.6 g) was then added, and the combined mixture was stirred for 110 min at 1600 to 1800 rpm.
[0034] The results of viscosity measurements at 300 rpm and 40° F. are shown in FIG. 3 . The results of syneresis measurements at 100° F. are shown in FIG. 4 .
Example 3
[0035] Example 3 illustrates the results obtained from a slurry concentrate prepared according to the present invention in comparison to a previous slurry concentrate of Example 2. The additives were prepared as described in Examples 1 and 2 above. A control sample using an organoclay prepared from bentonite and methyl benzyl dihydrogenated tallow quaternary ammonium salt (2 M 2 HT) was prepared. The procedure described in example 2 was used to evaluate the slurry concentrate. For the particular lot of guar used in this example, the concentration of bentonite/2 M 2 HT organoclay in the formulation to achieve the target parameters was 2.4 wt. %. This achieved an average viscosity of 260 cP at 300 rpm at 40° F., and a syneresis after 3 days at 100° F. of 1%. The control slurry concentrate was compared to the slurry concentrates prepared in Examples 1 and 2.
[0036] The results of the comparison are summarized in FIG. 5 . The slurry concentrates, prepared according to the present invention, using hectorite/3 MHT organoclay shows superior performance. In particular, the additive prepared using the dry process of Example 1 shows significantly reduced viscosity with similar syneresis, which is a desirable feature for a slurry concentrate. FIG. 5 also illustrates a maximum viscosity acceptable for commercial application of a slurry concentrate.
[0037] FIG. 6 shows the comparative syneresis results for the slurry concentrate prepared according to Examples 1 and 2 using hectorite/3 MHT and the additive prepared using bentonite/2 M 2 HT. The slurry concentrate containing hectorite/3 MHT organoclay showed superior performance. FIG. 6 also illustrates a maximum syneresis acceptable for commercial application of a slurry concentrate.
[0038] The slurry concentrate containing hectorite/3 MHT organoclay, when combined with hydrocarbons or oils, result in unexpected and useful performance characteristics. In particular, slurry concentrates using hectorite/3 MHT organoclay, when combined with hydrocarbons or oils, provide a slurry having a 300 rpm viscosity of less than 300 at 40° F., a 300 rpm viscosity greater than 120 at room temperature, a syneresis of less than 1% after 3 days at room temperature, and a syneresis of less than 2.5% after 1 day at 100° F. | The invention relates to a slurry concentrate which contains a viscosity enhancing polymer and organohectorite clay, which exhibits an unexpected improvement in viscosity and syneresis while exhibiting improved safety characteristics. | 2 |
RELATED APPLICATION INFORMATION
[0001] This application is a continuation of Ser. No. 09/291,129, filed Apr. 12, 1999, which is a continuation-in-part of application Ser. No. 09/030,156, filed Feb. 25, 1998, now U.S. Pat. No. 6,207,373, entitled “METHODS AND APPARATUS FOR DETERMINATION OF LENGTH POLYMORPHISMS IN DNA”, which is a continuation-in-part of application Ser. No. 08/986,065, filed Dec. 5, 1997, now U.S. Pat. No. 6,051,380, entitled “METHODS AND PARAMETERS FOR ELECTRONIC BIOLOGICAL DEVICES”, which is a continuation-in-part of application Ser. No. 08/534,454, filed Sep. 27, 1995, now U.S. Pat. No. 5,849,486, entitled “APPARATUS AND METHODS FOR ACTIVE PROGRAMMABLE MATRIX DEVICES”, which is a continuation-in-part of application Ser. No. 08/304, 657, filed Sep. 9, 1994, now U.S. Pat. No. 5,632,957, entitled “AUTOMATED MOLECULAR BIOLOGICAL DIAGNOSTIC SYSTEM,” (which has been continued into application Serial No. 08,859,644, filed May 20, 1997, now pending, entitled “CONTROL SYSTEM FOR ACTIVE, PROGRAMMABLE ELECTRONIC MICROBIOLOGY SYSTEM”), which is a continuation-in-part of application Ser. No. 08/271,882, filed Jul. 7, 1994, now U.S. Pat. No. 6,017,696, entitled “METHODS FOR ELECTRONIC STRINGENCY CONTROL FOR MOLECULAR BIOLOGICAL ANALYSIS AND DIAGNOSTICS”, which is a continuation-in-part of Ser. No. 08/146,504, filed Nov. 1, 1993, now U.S. Pat. No. 5,605,662, entitled “ACTIVE PROGRAMMABLE DEVICES FOR MOLECULAR BIOLOGICAL ANALYSIS AND DIAGNOSTICS”, (which has been continued into application Ser. No. 08/725,976, filed Oct. 4, 1996, now U.S. Pat. No. 5,605,208, entitled ‘METHODS FOR ELECTRONIC SYNTHESIS OF POLYMERS”), and also a continuation-in-part of application Ser. No. 08/708,262, filed Sep. 16, 1996, now abandoned, entitled “METHODS AND MATERIALS FOR OPTIMIZATION OF ELECTRONIC HYBRIDIZATION REACTIONS”, all incorporated herein by reference as if fully set forth herein.
FIELD OF THE INVENTION
[0002] The methods of this invention relate to systems for genetic identification for disease states and other gene related afflictions. More particularly, the methods relate to systems for the detection of single nucleic acid polymorphisms in nucleic acid sequences for the identification of polymorphisms in viruses, and eukaryotic and prokaryotic genomes.
BACKGROUND OF THE INVENTION
[0003] The following description provides a summary of information relevant to the present invention. It is not an admission that any of the information provided herein is prior art to the presently claimed invention, nor that any of the publications specifically or implicitly referenced are prior art to that invention.
[0004] Molecular biology comprises a wide variety of techniques for the analysis of nucleic acid and protein sequences. Many of these techniques and procedures form the basis of clinical diagnostic assays and tests. These techniques include nucleic acid hybridization analysis, restriction enzyme analysis, genetic sequence analysis, and the separation and purification of nucleic acids and proteins (See, e.g., J. Sambrook, E. F. Fritsch, and T. Maniatis, Molecular Cloning: A Laboratory Manual, 2 Ed., Cold spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1989).
[0005] Most of these techniques involve carrying out numerous operations (e.g., pipetting, centrifugation, and electrophoresis) on a large number of samples. They are often complex and time consuming, and generally require a high degree of accuracy. Many a technique is limited in its application by a lack of sensitivity, specificity, or reproducibility.
[0006] For example, the complete process for carrying out a DNA hybridization analysis for a genetic or infectious disease is very involved. Broadly speaking, the complete process may be divided into a number of steps and sub-steps. In the case of genetic disease diagnosis, the first step involves obtaining the sample (e.g., saliva, blood or tissue). Depending on the type of sample, various pre-treatments would be carried out. The second step involves disrupting or lysing the cells which releases the crude DNA material along with other cellular constituents.
[0007] Generally, several sub-steps are necessary to remove cell debris and to further purify the DNA from the crude sample. At this point several options exist for further processing and analysis. One option involves denaturing the DNA and carrying out a direct hybridization analysis in one of many formats (dot blot, microbead, microplate, etc.). A second option, called Southern blot hybridization, involves cleaving the DNA with restriction enzymes, separating the DNA fragments on an electrophoretic gel, blotting the DNA to a membrane filter, and then hybridizing the blot with specific DNA probe sequences. This procedure effectively reduces the complexity of the genomic DNA sample, and thereby helps to improve the hybridization specificity and sensitivity. Unfortunately, this procedure is long and arduous. A third option is to carry out an amplification procedure such as the polymerase chain reaction (PCR) or the strand displacement amplification (SDA) method. These procedures amplify (increase) the number of target DNA sequences relative to non-target sequences. Amplification of target DNA helps to overcome problems related to complexity and sensitivity in genomic DNA analysis. After these sample preparation and DNA processing steps, the actual hybridization reaction is performed. Finally, detection and data analysis convert the hybridization event into an analytical result.
[0008] Nucleic acid hybridization analysis generally involves the detection of a very small number of specific target nucleic acids (DNA or RNA) with an excess of probe DNA, among a relatively large amount of complex non-target nucleic acids. A reduction in the complexity of the nucleic acid in a sample is helpful to the detection of low copy numbers (i.e. 10,000 to 100,000) of nucleic acid targets. DNA complexity reduction is achieved to some degree by amplification of target nucleic acid sequences. (See, M. A. Innis et al., PCR Protocols: A Guide to Methods and Applications, Academic Press, 1990, Spargo et al., 1996 , Molecular & Cellular Probes, in regard to SDA amplification). This is because amplification of target nucleic acids results in an enormous number of target nucleic acid sequences relative to non-target sequences thereby improving the subsequent target hybridization step.
[0009] The actual hybridization reaction represents one of the most important and central steps in the whole process. The hybridization step involves placing the prepared DNA sample in contact with a specific reporter probe at set optimal conditions for hybridization to occur between the target DNA sequence and probe.
[0010] Hybridization may be performed in any one of a number of formats. For example, multiple sample nucleic acid hybridization analysis has been conducted in a variety of filter and solid support formats (See G. A. Beltz et al., in Methods in Enzymology, Vol. 100, Part B, R. Wu, L. Grossman, K. Moldave, Eds., Academic Press, New York, Chapter 19, pp. 266-308, 1985). One format, the so-called “dot blot” hybridization, involves the non-covalent attachment of target DNAs to a filter followed by the subsequent hybridization to a radioisotope labeled probe(s). “Dot blot” hybridization gained wide-spread use over the past two decades during which time many versions were developed (see M. L. M. Anderson and B. D. Young, in Nucleic Acid Hybridization—A Practical Approach, B. D. Hames and S. J. Higgins, Eds., IRL Press, Washington, D.C. Chapter 4, pp. 73-111, 1985). For example, the dot blot method has been developed for multiple analyses of genomic mutations (D. Nanibhushan and D. Rabin, in EPA 0228075, Jul. 8, 1987) and for the detection of overlapping clones and the construction of genomic maps (G. A. Evans, in U.S. Pat. No. 5,219,726, Jun. 15, 1993).
[0011] New techniques are being developed for carrying out multiple sample nucleic acid hybridization analysis on micro-formatted multiplex or matrix devices (e.g., DNA chips) (see M. Barinaga, 253 Science, pp. 1489, 1991; W. Bains, 10 Bio/Technology, pp. 757-758, 1992). These methods usually attach specific DNA sequences to very small specific areas of a solid support, such as micro-wells of a DNA chip. These hybridization formats are micro-scale versions of the conventional “dot blot” and “sandwich” hybridization systems.
[0012] The micro-formatted hybridization can be used to carry out “sequencing by hybridization” (SBH) (see M. Barinaga, 253 Science, pp. 1489, 1991; W. Bains, 10 Bio/Technology, pp. 757-758, 1992). SBH makes use of all possible n-nucleotide oligomers (n-mers) to identify n-mers in an unknown DNA sample, which are subsequently aligned by algorithm analysis to produce the DNA sequence (see R. Drmanac and R. Crkvenjakov, Yugoslav Patent Application #570/87, 1987; R. Drmanac et al., 4 Genomics, 114, 1989; Strezoska et al., 88 Proc. Natl. Acad. Sci. USA 10089, 1992; and R. Drmanac and R. B. Crkvenjakov, U.S. Patent No. 5,202,231, Apr. 13, 1993).
[0013] There are two formats for carrying out SBH. The first format involves creating an array of all possible n-mers on a support, which is then hybridized with the target sequence. The second format involves attaching the target sequence to a support, which is sequentially probed with all possible n-mers. Both formats have the fundamental problems of direct probe hybridizations and additional difficulties related to multiplex hybridizations.
[0014] Southern, (United Kingdom Patent Application GB 8810400, 1988; E. M. Southern et al., 13 Genomics 1008, 1992), proposed using the first format to analyze or sequence DNA. Southern identified a known single point mutation using PCR amplified genomic DNA. Southern also described a method for synthesizing an array of oligonucleotides on a solid support for SBH. However, Southern did not address how to achieve optimal stringency conditions for each oligonucleotide on an array.
[0015] Drmanac et al., (260 Science 1649-1652, 1993), used the second format to sequence several short (116 bp) DNA sequences. Target DNAs were attached to membrane supports (“dot blot” format). Each filter was sequentially hybridized with 272 labeled 10-mer and 11-mer oligonucleotides. Wide ranges of stringency conditions were used to achieve specific hybridization for each n-mer probe. Washing times varied from 5 minutes to overnight using temperatures from 0° C. to 16° C. Most probes required 3 hours of washing at 16° C. The filters had to be exposed from 2 to 18 hours in order to detect hybridization signals. The overall false positive hybridization rate was 5% in spite of the simple target sequences, the reduced set of oligomer probes, and the use of the most stringent conditions available.
[0016] Currently, a variety of methods are available for detection and analysis of the hybridization events. Depending on the reporter group (fluorophore, enzyme, radioisotope, etc.) used to label the DNA probe, detection and analysis are carried out fluorimetrically, calorimetrically, or by autoradiography. By observing and measuring emitted radiation, such as fluorescent radiation or particle emission, information may be obtained about the hybridization events. Even when detection methods have very high intrinsic sensitivity, detection of hybridization events is difficult because of the background presence of non-specifically bound materials. Thus, detection of hybridization events is dependent upon how specific and sensitive hybridization can be made. Concerning genetic analysis, several methods have been developed that have attempted to increase specificity and sensitivity.
[0017] One form of genetic analysis is analysis centered on elucidation of single nucleic acid polymorphisms or (“SNPs”). Factors favoring the usage of SNPs are their high abundance in the human genome (especially compared to short tandem repeats, (STRs)), their frequent location within coding or regulatory regions of genes (which can affect protein structure or expression levels), and their stability when passed from one generation to the next (Landegren et al., Genome Research, Vol. 8, pp. 769-776, 1998).
[0018] A SNP is defined as any position in the genome that exists in two variants and the most common variant occurs less than 99% of the time. In order to use SNPs as widespread genetic markers, it is crucial to be able to genotype them easily, quickly, accurately, and cost-effectively. It is of great interest to type both large sets of SNPs in order to investigate complex disorders where many loci factor into one disease (Risch and Merikangas, Science, Vol. 273, pp. 1516-1517, 1996), as well as small subsets of SNPs previously demonstrated to be associated with known afflictions.
[0019] Numerous techniques are currently available for typing SNPs (for review, see Landegren et al., Genome Research, Vol. 8, pp. 769-776,1998), all of which require target amplification. They include direct sequencing (Carothers et al., BioTechniques, Vol. 7, pp. 494-499, 1989), single-strand conformation polymorphism (Orita et al., Proc. Natl. Acad. Sci. USA, Vol. 86, pp. 2766-2770, 1989), allele-specific amplification (Newton et al., Nucleic Acids Research, Vol. 17, pp. 2503-2516, 1989), restriction digestion (Day and Humphries, Analytical Biochemistry, Vol. 222, pp. 389-395, 1994), and hybridization assays. In their most basic form, hybridization assays function by discriminating short oligonucleotide reporters against matched and mismatched targets. Due to difficulty in determining optimal denaturation conditions, many adaptations to the basic protocol have been developed. These include ligation chain reaction (Wu and Wallace, Gene, Vol. 76, pp. 245-254, 1989) and minisequencing (Syvänen et al., Genomics, Vol. 8, pp. 684-692, 1990). Other enhancements include the use of the 5′-nuclease activity of Taq DNA polymerase (Holland et al., Proc. Natl. Acad. Sci. USA, Vol. 88, pp. 7276-7280, 1991), molecular beacons (Tyagi and Kramer, Nature Biotechnology, Vol. 14, pp.303-308, 1996), heat denaturation curves (Howell et al., Nature Biotechnology, Vol. 17, pp. 87-88, 1999) and DNA “chips” (Wang et al., Science, Vol. 280, pp. 1077-1082, 1998). While each of these assays are functional, they are limited in their practical application in a clinical setting.
[0020] An additional phenomenon discovered to be useful in distinguishing SNPs is the nucleic acid interaction energies or base-stacking energies derived from the hybridization of multiple target specific probes to a single target. (see R. Ornstein et al., “An Optimized Potential Function for the Calculation of Nucleic Acid Interaction Energies”, in Biopolymers, Vol. 17, 2341-2360 (1978); J. Norberg and L. Nilsson, Biophysical Journal, Vol. 74, pp. 394-402, (1998); and J. Pieters et al., Nucleic Acids Research, Vol. 17, no. 12, pp. 4551-4565 (1989)). This base-stacking phenomenon is used in a unique format in the current invention to provide highly sensitive Tm differentials allowing the direct detection of SNPs in a nucleic acid sample.
[0021] Prior to the format of the current invention, other methods have been used to distinguish nucleic acid sequences in related organisms or to sequence DNA. For example, U.S. Pat. No. 5,030,557 by Hogan et al. disclosed that the secondary and tertiary structure of a single stranded target nucleic acid may be affected by binding “helper” oligonucleotides in addition to “probe” oligonucleotides causing a higher Tm to be exhibited between the probe and target nucleic acid. That application however was limited in its approach to using hybridization energies only for altering the secondary and tertiary structure of self-annealing RNA strands which if left unaltered would tend to prevent the probe from hybridizing to the target.
[0022] With regard to DNA sequencing, K. Khrapko et al., Federation of European Biochemical Societies Letters, Vol. 256, no. 1,2, pp. 118-122 (1989), for example, disclosed that continuous stacking hybridization resulted in duplex stabilization. Additionally, J. Kieleczawa et al., Science, Vol. 258, pp. 1787-1791 (1992), disclosed the use of contiguous strings of hexamers to prime DNA synthesis wherein the contiguous strings appeared to stabilize priming. Likewise, L. Kotler et al., Proc. Natl. Acad. Sci. USA, Vol. 90, pp. 4241-4245, (1993) disclosed sequence specificity in the priming of DNA sequencing reactions by use of hexamer and pentamer oligonucleotide modules. Further, S. Parinov et al., Nucleic Acids Research, Vol. 24, no. 15, pp. 2998-3004, (1996), disclosed the use of base-stacking oligomers for DNA sequencing in association with passive DNA sequencing microchips. Moreover, G. Yershov et al., Proc. Natl. Acad. Sci. USA, Vol. 93, pp. 4913-4918 (1996), disclosed the application of base-stacking energies in SBH on a passive microchip. In Yershov's example, 10-mer DNA probes were anchored to the surface of the microchip and hybridized to target sequences in conjunction with additional short probes, the combination of which appeared to stabilize binding of the probes. In that format, short segments of nucleic acid sequence could be elucidated for DNA sequencing. Yershov further noted that in their system the destabilizing effect of mismatches was increased using shorter probes (e.g., 5-mers). Use of such short probes in DNA sequencing provided the ability to discern the presence of mismatches along the sequence being probed rather than just a single mismatch at one specified location of the probe/target hybridization complex. Use of longer probes (e.g., 8-mer, 10-mer, and 13-mer oligos) were less functional for such purposes.
[0023] An additional example of methodologies that have used base-stacking in the analysis of nucleic acids includes U.S. Pat. No. 5,770,365 by Lane et al., wherein is disclosed a method of capturing nucleic acid targets using a unimolecular capture probe having a single stranded loop and a double stranded region which acts in conjunction with a binding target to stabilize duplex formation by stacking energies.
[0024] Despite the knowledge of base-stacking phenomenon, applications as described above have not resulted in commercially acceptable methods or protocols for either DNA sequencing or the detection of SNPs for clinical purposes. We provide herein such a commercially useful method for making such distinctions in numerous genetic and medical applications by combining the use of base-stacking principles and electronically addressable microchip formats.
SUMMARY OF THE INVENTION
[0025] Methods are provided for the analysis and determination of SNPs in a genetic target. In one embodiment of the invention, SNPs in a target nucleic acid are determined using a single capture site on an electronically addressable microchip (e.g, an APEX type microchip). In this embodiment, both wild type and mutant alleles are distinguished, if present in a sample, at a single capture site by detecting the presence of hybridized allele-specific probes labeled with fluorophores sensitive to excitation at various wave lengths. In another embodiment, base-stacking energies of at least two oligonucleotides are used in conjunction with an APEX type bioelectronic microchip.
[0026] The electronically facilitated method using an APEX type microchip offers several advantages over passive-based hybridization assays when base-stacking is employed. First, electronic addressing under low salt conditions in the presence of stabilizer oligomer inhibits rehybridization of amplicon strands in situations where amplification of target nucleic acid is carried out. This obviates the need for asymmetric amplification or other more complex methods of strand separation. Electronically facilitated methods additionally allow multiple different amplicons to be addressed to discrete sites thereby greatly facilitating multiplexing of multiple patients or multiple amplicons on an open microchip.
[0027] In one embodiment of our system, the amplicons of the target nucleic acid may be anchored to an electronic microchip capture site (i.e. “amplicon down” format) such that multiple amplicons may be placed at the same capture site. The amplicons may be anchored to the capture site on the microchip by attachment moieties located at the 5′ end of the amplicon. Such attachment moieties can be binding agents such a biotin incorporated into one of the amplification primers. The anchored nucleic acids may in turn be probed simultaneously or sequentially.
[0028] By way of example, in implementation of the amplicon down format, a target nucleic acid is first amplified, such as by PCR, SDA, NASBA, TMA, rolling circle, T7, T3, or SP6, each of which methods are well understood in the art, using at least one amplification primer oligomer that is labeled with a moiety useful for attaching the amplification product to a substrate surface. In one embodiment, a biotin moiety can be attached at the 5′ end of the primer. Following amplification, the labeled amplified dsDNA product may be denatured electronically or thermally and addressed to a specified capture site on the microchip surface, thereby making the amplicon behave as an anchored capture moiety. In a preferred embodiment, the complementary strand to the labeled amplification product (i.e., the non-labeled strand) is kept from reannealing to the labeled product by a “stabilizer” oligomer which is inputted into the process during electronic biasing of the labeled targeted amplicon to the capture site. The use of a “stabilizer” oligomer, as provided for in this invention, is unique in that unlike prior base-stacking inventions, it functionally serves two purposes (i.e., to hinder reannealing of complementary amplicons during electronic addressing of the biotinylated target amplicons, and to provide a base-stacking energy moiety for interaction with the second oligomer. This combined functionality effectively lessens the complexity of SNP determination in a microchip format).
[0029] Application of site-specific electronic biasing can allow for directed influencing of the ionic environment at the site of hybridization as well as continuous adjustment of hybridization conditions both during and after hybridization. Such manipulation of electronic environment (specifically the dielectric constant of the solution) can be used to influence directly the base-stacking energies between oligonucleotide probes. Additionally, hybridization is greatly accelerated by the concentration achieved during local electronic addressing. Such a system is also highly flexible in that it allows one to take advantage of both thermal and/or electronic discrimination after hybridization. Moreover, electronic biasing equally facilitates distinguishing hybridization mismatches occurring at the terminal nucleic acid pairs of a hybridized duplex as well as destabilizing mismatches occurring internally (e.g., due to destabilizing caused by misalignment of the base pairs). This ability to detect mismatches allows the current invention to be less restricted in choices for positioning the location of SNP bases on probes although generally, for purposes of this invention, mismatches are desired to occur at the terminal base of a probe. For instance, the SNP relevant base may be incorporated as the terminal base of the reporter probe such that when the stabilizer and reporter probes are annealed to the amplicon, the SNP relevant base will lie adjacent to one of the terminal bases of the stabilizer when both the stabilizer and reporter are annealed adjacently to one another on a target nucleic acid strand.
[0030] Sensitivity and robustness may further be enhanced by the additional inclusion of yet another probe (i.e., the “interfering” probe) designed to be complementary to the non-labeled strand of the amplicon. Use of this probe further helps to compete away the undesired non-labeled amplicon strand from reannealing to the labeled strand.
[0031] In another format of this system, when the stabilizer probe is anchored (i.e. “capture down” format), the system is also simple and multiple amplicons may be placed at the same capture site. These may then be probed simultaneously or sequentially. Generally, although not exclusively, the stabilizer probe will be anchored to the substrate at its 5′ end. Such an arrangement necessarily provides that the SNP base will be complementary to either the 3′ base of the stabilizer/capture or the 5′ base of the reporter probe. Conversely, if the 3′ end of the stabilizer/capture is anchored, then the SNP base will be complementary to either the 5′ base of the stabilizer/capture or the 3′ base of the reporter probe.
[0032] By way of example, in implementation of this capture down format, a target nucleic acid is first amplified, such as by PCR or SDA. The amplified dsDNA product is then denatured and addressed to a specified capture site on the microchip surface that has an anchored stabilizer/capture moiety. In a preferred embodiment, the complementary strand to the desired amplification product strand is kept from reannealing to the desired strand by the stabilizer/capture oligomer that, as described above, serves as a first probe that also participates in base-stacking with a second reporter probe. As in the amplicon down method, the stabilizer/capture oligomer as provided for in this invention is unique in that unlike prior base-stacking inventions, it functionally serves two purposes (i.e., to hinder reannealing of complementary amplicons during electronic addressing of the target amplicons and to provide a base-stacking energy moiety for interaction with reporter oligomer thereby lessening the complexity of SNP determination in a microchip format). As with the target down format, interfering probes may be used. Moreover, multiple amplicons may be probed at any particular capture site.
[0033] In yet another format, multiple SNPs in a target sequence may be detected. In this format, either of the above mentioned amplicon down or capture down formats may be employed. In this format, multiple base-stacking may be used to resolve the presence of closely spaced SNPs at a single locus. For example, where two SNPs are closely spaced, at least two short reporter. oligonucleotides may be base-stacked against a longer stabilizer oligonucleotide. Each reporter may be labeled with a different fluorophore specific for the allele that occurs at each site. For instance, if a locus has two SNPs in close proximity to one another, reporter probes incorporating the wild-type and mutant bases of each SNP site, each containing a different fluorophore may be used to determine which allele is present.
[0034] In yet another embodiment of the invention, SNPs in a target nucleic acid are determined using combined base-stacking energies derived from both 5′ and 3′ ends of a single reporter probe. In this embodiment, the target nucleic acid is amplified (such as by PCR and preferably via the strand displacement amplification (SDA) technique) such that two spaced amplicons of the target are generated. The two amplicons (a first and a second amplicon) may be from the same genetic locus wherein the sequences are closely spaced, or may be from divergent or unrelated genetic loci. In either case, both the amplicon down and the capture down formats may be used. In the case where the capture down format is used, the stabilizer/capture is designed as a “bridging” stabilizer/capture probe to capture both amplicons in a spaced apart fashion so that at least one reporter probe, which may or may not contain SNP sequence at one or the other end, can be “nested” between the amplicons. Where the amplicon down format is used, only one of the amplicons is anchored and a “bridging” stabilizer/capture probe having sequence complementary to the anchored amplicon and the non-anchored amplicon is employed to hybridize the amplicons in a spaced apart fashion allowing at least one reporter probe to be nested. Where multiple SNPs are associated at such a loci, more than one SNP containing reporter probe may be nested and take advantage of multiple base-stacking energies.
[0035] In the case where the amplicons are from different loci, the amplicons may be brought into close proximity with one another using either an anchored bridging stabilizer/capture probe, or an anchored amplicon and a bridging stabilizer/capture probe as described above. The presence of both amplicon sequences may be detected using a reporter probe designed to nest between the captured amplicons using base-stacking energies to stabilize the reporter hybridization as described above. As with the earlier described formats, the reporter probe may incorporate at either and/or both its 5′ and 3′ ends SNP or wild-type sequence associated with either or both loci.
[0036] In a further embodiment, the SNP containing region may contain multiple SNPs and reporter probes can be designed so that more than one reporter probe is used to nest between the first and second amplicons such that each reporter has at least one nucleic acid base on either its 3′ or 5′ end corresponding to a SNP. Thus, such a system can benefit from both multiple reporter signals and multiple base-stacking energies from nesting probes that possess either a single base corresponding to either SNP or wild-type at either the 3′ or 5′ end, or that contain such bases at both 3′ and 5′ ends, thereby increasing sensitivity.
[0037] In another embodiment the stabilizer oligomers are generally 20 to 44-mers and preferably about 30-mers, while the reporter probes are generally 10 to 12-mers and preferably about 11-mers. The lengths of such probes are highly effective in accordance with their use in an electronically addressable microchip format. Reporter probes shorter than 8-mers are generally not functional in the ionic environment of the current system.
[0038] In the preferred embodiment of the invention, electronically aided hybridization is utilized in the process. In one aspect, during the hybridization of the nucleic acid target with the stabilizer probe and/or the reporter probe, electronic stringent conditions may be utilized, preferably along with other stringency affecting conditions, to aid in the hybridization. This technique is particularly advantageous to reduce or eliminate slippage hybridization among probes and target, and to promote more effective hybridization. In yet another aspect, electronic stringency conditions may be varied during the hybridization complex stability determination so as to more accurately or quickly determine whether a SNP is present in the target sequence.
[0039] Hybridization stability may be influenced by numerous factors, including thermoregulation, chemical regulation, as well as electronic stringency control, either alone or in combination with the other listed factors. Through the use of electronic stringency conditions, in either or both of the target hybridization step or the reporter oligonucleotide stringency step, rapid completion of the process may be achieved. Electronic stringency hybridization of the target is one distinctive aspect of this method since it is amenable with double stranded DNA and results in rapid and precise hybridization of the target to the capture site. This is desirable to achieve properly indexed hybridization of the target DNA to attain the maximum number of molecules at a test site with an accurate hybridization complex. By way of example, with the use of electronic stringency, the initial hybridization step may be completed in ten minutes or less, more preferably five minutes or less, and most preferably two minutes or less. Overall, the analytical process may be completed in less than half an hour.
[0040] As to detection of the hybridization complex, it is preferred that the complex is labeled. Typically, in the step of determining hybridization of probe to target, there is a detection of the amount of labeled hybridization complex at the test site or a portion thereof. Any mode or modality of detection consistent with the purpose and functionality of the invention may be utilized, such as optical imaging, electronic imaging, use of charge-coupled devices or other methods of quantification. Labeling may be of the target, capture, or reporter. Various labeling may be by fluorescent labeling, colormetric labeling or chemiluminescent labeling. In yet another implementation, detection may be via energy transfer between molecules in the hybridization complex. In yet another aspect, the detection may be via fluorescence perturbation analysis. In another aspect the detection may be via conductivity differences between concordant and discordant sites.
[0041] In yet another aspect, detection can be carried out using mass spectrometry. In such method, no fluorescent label is necessary. Rather detection is obtained by extremely high levels of mass resolution achieved by direct measurement, for example, by time of flight or by electron spray ionization (ESI). Where mass spectrometry is contemplated, reporter probes having a nucleic acid sequence of 50 bases or less are preferred.
[0042] It is yet a further object of this invention to provide methods that may effectively provide for genetic identification.
[0043] It is yet a further object of this invention to provide systems and methods for the accurate detection of diseased states, especially clonal tumor disease states, neurological disorders and predisposition to genetic disease.
[0044] It is yet a further object of this invention to provide a rapid and effective system and methods for identification, such as in forensics and paternity applications.
[0045] Yet a further object of the invention is to identify SNPs in infectious organisms such as those responsible for antibiotic resistance or that can be used for identification of specific organisms.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] [0046]FIG. 1A is a cross sectional view of one embodiment of an active matrix device useful in accordance with the methods of this invention.
[0047] [0047]FIG. 1B is a perspective view of an active array device useful with the methods of this invention.
[0048] [0048]FIG. 2 is a schematic representation of one embodiment of the method of electronic SNP scoring by a dual fluorescent base-stacking format wherein the target amplicon population comprises wild-type and/or mutant alleles. In this format, one of the target strands is anchored to the capture site (“amplicon down” format). As shown, wild type and mutant alleles may be probed at a single capture site. Where the target includes both alleles, (i.e., heterozygote) reporter probes corresponding to each allele will be detected. Where only one allele is present, (i.e., homozygote) only one reporter probe will be detected. The figure represents detection of a homozygote population.
[0049] [0049]FIG. 3 is a representation of one embodiment of the method of electronic SNP scoring by dual fluorescent base-stacking format wherein the stabilizing probe is anchored to the capture site (“capture down” format). Additionally this figure demonstrates the use of interfering probes to compete out undesired amplicon strands. As is similarly demonstrated in FIG. 2, wild type and mutant alleles may be detected.
[0050] [0050]FIGS. 4 a and 4 b represent one embodiment of the method wherein base-stacking energies of multiple reporter probes are utilized. FIG. 4 a shows the capture down format while FIG. 4 b shows amplicon down format. This multiple base stacking approach is applicable where a target possesses closely spaced SNPs.
[0051] [0051]FIG. 5 represents one embodiment of the invention wherein base-stacking energies are provided by nesting a reporter probe between two target amplicons. In this example, the stabilizer probe has nucleic acid base sequence complementary to both target amplicons. The figure depicts amplicon down format although capture down is equally applicable. Stabilization of the reporter probe in nested fashion signals the presence of both target species and/or any SNP integrated into the 5′ or 3′ terminus, or into both termini, of the reporter probe.
[0052] [0052]FIG. 6 shows that the nested embodiment illustrated in FIG. 5 may also utilize multiple base-stacking energies of multiple reporter probes, each of which may include SNPs. As with the other formats, both amplicon and capture down formats are useful.
[0053] [0053]FIG. 7 shows a nested format in which amplification is carried out using SDA. In this embodiment, the termini of the amplicons necessarily possess sequence related to primers used in SDA that contain an endonuclease restriction site. In this embodiment, SNPs may be either in the reporter termini or alternatively be in amplicon sequence immediately internal to the SDA primer sequence. In either case, mismatches can be detected by destabilizing hybridization of the reporter probe due to mismatches on the reporter itself or mismatches in the amplicon sequence. Additionally, amplicons generated using SDA may use either amplicon or capture down format (capture down shown) and may use multiple reporter stacking.
[0054] [0054]FIGS. 8 a and 8 b are photographs showing hybridization results on the same microchip capture sites using reporter probes corresponding to wild type. and mutant alleles labeled with fluorophores sensitive to two different wavelengths. Results show that homozygous mutant, homozygous wild type, and heterozygosity is clearly detectable. Specifically, the importance of stabilizer oligomer for scoring Factor V SNPs is represented. Five unknown Factor V samples (labeled A through E) were amplified using primers Seq. Id. No. 1 (Biotin-TGTTATCACACTGGTGCTAA) and Seq. Id. No. 2 (ACTACAGTGACGTGGACATC). The amplification product was then electronically targeted to 4 capture sites (columns 1,2, 4, and 5) using a direct current of 400 nAmps/site for 2 minutes. Column 3 was mock targeted and served as background control. The array was then treated with 0.5×SSC, pH 12 for 5 minutes to denature any rehybridized amplified products. Next, 125 nM Factor V stabilizer oligo, Seq. Id. No. 3 (TAATCTGTAAGAGCAGATCCCTGGACAGGC), was electronically biased using direct current of 400 nAps/site to all capture sites in column 1 for 15 seconds, column 2 for 30 seconds, and column 4 for 60 seconds. Column 5 was biased for 60 seconds with buffer only. Final discrimination of the allele-specific reporters at each capture site was achieved at 32° C. in our low salt buffer. The reporter oligomers were a CR6G labeled wild type reporter, Seq. Id. No. 4 (GAGGAATACAG-CR6G), and a Far-Red labeled mutant reporter, Seq. Id. No. 5 (AAGGAATACAG-Far-Red). Results indicate that Samples A and B are homozygous for mutant, Sample C is heterozygous for mutant and wild type, and Samples D and E are homozygous for wild type.
[0055] [0055]FIG. 9 is a photograph showing that base-stacking energy stabilizes oligo reporters. Wild type Hemochromatosis sample was amplified using Seq. Id. No. 6 (Biotin-TGAAGGATAAGCAGCCAAT) and Seq. Id. No. 7 (CTCCTCTCAACCCCCAATA). The amplified sample was then mixed with either (i), no stabilizer oligo (column 1); (ii), 1 μM of the standard Hemochromatosis stabilizer oligomer in which case the stabilizer hybridizes adjacent to the reporter probe (column 2), Seq. Id. No. 8 (GGCTGATCCAGGCCTGGGTGCTCCACCTGG); (iii), a stabilizer oligomer that hybridizes to target with a one base gap between the stabilizer and reporter probe (column 4), Seq. Id. No. 9 (GGGCTGATCCAGGCCTGGGTGCTCCACCTG); or (iv), a stabilizer oligomer Seq. Id. No. 10 (CACAATGAGGGGCTGATCCAGGCCTGGGTG) resulting in a 10 bp gap between itself and the reporter (column 5). The resulting samples were biased simultaneously to two capture sites for a total of 4 minutes using a biased alternating current protocol wherein 700 nAmps/site at 38 msec ‘+’ and 10 msec ‘−’ was used. Column 3 was mock targeted and served as a background control. After passive reporting with wild type reporter oligomer, Seq. Id. No. 11 (CACGTATATCT-CR6G), thermal discrimination of the reporter probe was attained at 32° C. in our low salt buffer. The images represent the wild type reporter only, both before (initial signal) and after thermal denaturation (post-discrimination). Only in the situation where the stabilizer and reporter probes were adjacent was the hybridization stabilized. The same result is obtainable using mutant (data not shown).
[0056] [0056]FIG. 10 shows the impact of stabilizer oligo on signal intensity. An amplified wild type Hemochromatosis sample was mixed with either the standard 30-mer stabilizer oligo (Seq. Id. No. 8), non-complementary random DNA (six different 20-mer to 24-mer oligos), or no DNA (water) at three concentrations (10 nM, 100 nM, and 1 μM). Each combination was biased to duplicate capture sites for 4 minutes using a biased alternating current protocol 800 nAmps/site at 38 msec ‘+’ and 10 msec ‘−’. Capture sites that received either no DNA or random DNA were subsequently biased for 1 minute with 125 nM stabilizer oligo, while capture sites that already received stabilizer were biased for 1 minute with buffer only. Biasing conditions were direct current at 400 nAmps/site. The histogram represents the signal intensities of both the wild type (Seq. Id. No. 11) and mutant (Seq. Id. No. 12, TACGTATATCT-Far Red) reporters post-discrimination, achieved at 28° C.
[0057] Background from capture sites addressed with no DNA was subtracted.
[0058] [0058]FIG. 11 is a chart illustrating that the allele content of unknown Hemochromatosis samples is readily determinable. Sixteen amplified, unknown Hemochromatosis samples were tested using 1 μM Hemochromatosis stabilizer oligo (Seq. Id. No. 8). The samples and stabilizer were electronically targeted to individual capture sites on a 25-site microarray. Biasing was carried out for 4 minutes using an alternating current of 700 nAmps/site at 38 msec ‘+’ and 10 msec ‘−’. Following passive reporting of the two allele-specific reporters (i.e., wild-type Seq. Id. No. 11 or mutant Seq. Id. No. 12), thermal discrimination was achieved at 29° C. The histogram represents the mean fluorescent intensities minus background (signal intensity from a mock targeted site). Results show that samples 1, 7, and 12 are heterozygous, samples 3, 4, 8, 9, 11, 13, and 16 are homozygous for wild type, and samples 2, 5, 6, 10, 14, and 15 are homozygous for mutant.
[0059] [0059]FIG. 12 is a photograph showing multiplex analysis of Hemochromatosis and Factor V. In this figure, the results for Factor V were derived from use of the opposite strand to the results shown in FIG. 8. Two known Hemochromatosis and Factor V samples were each amplified individually. In this case, Factor V samples were amplified using primers Seq. Id. No. 13 (Biotin-ACTACAGTGACGTGGACATC) and Seq. Id. No. 14 (TGTTATCACACTGGTGCTAA). The amplification products were then combined together along with 1 μM of each of their 30-mer stabilizer oligos (i.e., Seq. Id. No. 8 and Seq. Id. No. 15 (TTACTTCAAGGACAAAATACCTGTATTCCT)). Each mixture was electronically biased in quadruplicate for 4 minutes using a biased alternative current of 700 nAmps/site at 38 msec ‘+’ and 10 msec ‘−’. The capture site in column 1 and 2 received a Hemochromatosis wild type and Factor V mutant, while the sites in column 4 and 5 were targeted with both Hemochromatosis and Factor V Heterozygotes. Column 3 was the background control. Reporting was done sequentially, first with the allele-specific Hemochromatosis reporters (Seq. Id. Nos. 11 and 12) and then the allele-specific Factor V reporters (Seq. Id. Nos. 16 (CGCCTGTCCAG-CR6G) and 17 (TGCCTGTCCAG-Far Red). Before Factor V reporters were passively hybridized, all remaining Hemochromatosis reporters were stripped from the microarray. In this experiment, heat discrimination in the low salt buffer was achieved at 28° C. for Hemochromatosis and 43° C. for Factor V. Stripping was carried out at 55° C. in our low salt buffer. The images represent the fluorescent signals from both the wild type and mutant reporters, all after thermal denaturation.
DETAILED DESCRIPTION OF THE INVENTION
[0060] [0060]FIGS. 1A and 1B illustrate a simplified version of the active programmable electronic matrix hybridization system for use with this invention. Generally, a substrate 10 supports a matrix or array of electronically addressable microlocations 12 . For ease of explanation, the various microlocations in FIG. 1A have been labeled 12 A, 12 B, 12 C and 12 D. A permeation layer 14 is disposed above the individual electrodes 12 . The permeation layer permits transport of relatively small charged entities through it, but limits the mobility of large charged entities, such as DNA, to keep the large charged entities from easily contacting the electrodes 12 directly during the duration of the test. The permeation layer 14 reduces the electrochemical degradation that would occur to the DNA by direct contact with the electrodes 12 , possibility due, in part, to extreme pH resulting from the electrolytic reaction. It further serves to minimize the strong, non-specific adsorption of DNA to electrodes. Attachment regions 16 are disposed upon the permeation layer 14 and provide for specific binding sites for target materials. The attachment regions 16 have been labeled 16 A, 16 B, 16 C and 16 D to correspond with the identification of the electrodes 12 A-D, respectively.
[0061] In operation, reservoir 18 comprises that space above the attachment regions 16 that contains the desired, as well as undesired, materials for detection, analysis or use. Charged entities 20 , such as charged DNA are located within the reservoir 18 . In one aspect of this invention, the active, programmable, matrix system comprises a method for transporting the charged material 20 to any of the specific microlocations 12 . When activated, a microlocation 12 generates the free field electrophoretic transport of any charged entity 20 that may be functionalized for specific binding towards the electrode 12 . For example, if the electrode 12 A were made positive and the electrode 12 D negative, electrophoretic lines of force 22 would run between the electrodes 12 A and 12 D. The lines of electrophoretic force 22 cause transport of charged entities 20 that have a net negative charge toward the positive electrode 12 A. Charged materials 20 having a net positive charge move under the electrophoretic force toward the negatively charged electrode 12 D. When the net negatively charged entity 20 that has been functionalized for binding contacts the attachment layer 16 A as a result of its movement under the electrophoretic force, the functionalized specific binding entity 20 becomes attached to the attachment layer 16 A.
[0062] Before turning to a detailed discussion of the inventions of this patent, the general matter of terminology will be discussed. The term “single nucleic acid polymorphism” (SNP) as used herein refers to a locus containing simple sequence motif which is a mutation of that locus.
[0063] A “hybridization complex”, such as in a sandwich assay, typically will include at least two of target nucleic acid, stabilizer probe, and reporter probe.
[0064] An “array” as used herein typically refers to multiple test sites, minimally two or more test sites wherein discrimination between wild type and mutant polymorphisms can be carried out for any target sequence at each individual site. The typical number of test sites will be one for each locus to be tested such that heterozygocity or homozygocity for either allele are distinguishable at each site. The number of loci required for any particular test will vary depending on the application, with generally one for genetic disease analysis, one to five for tumor detection, and six, eight, nine, thirteen or more for paternity testing and forensics. The physical positioning of the test sites relative to one another may be in any convenient configuration, such as linear or in an arrangement of rows and columns.
[0065] In one mode, the hybridization complex is labeled and the step of determining amount of hybridization includes detecting the amounts of labeled hybridization complex at the test sites. The detection device and method may include, but is not limited to, optical imaging, electronic imaging, imaging with a CCD camera, integrated optical imaging, and mass spectrometry. Further, the detection, either labeled or unlabeled, is quantified, which may include statistical analysis. The labeled portion of the complex may be the target, the stabilizer, the reporter or the hybridization complex in toto. Labeling may be by fluorescent labeling selected from the group of, but not limited to, Cy3, Cy5, Bodipy Texas Red, Bodipy Far Red, Lucifer Yellow, Bodipy 630/650-X, Bodipy R6G-X and 5-CR 6G. Labeling may further be accomplished by colormetric labeling, bioluminescent labeling and/or chemiluminescent labeling. Labeling further may include energy transfer between molecules in the hybridization complex by perturbation analysis, quenching, electron transport between donor and acceptor molecules, the latter of which may be facilitated by double stranded match hybridization complexes (See, e.g., Tom Meade and Faiz Kayyem, Electron Transfer Through DNA:Site-Specific Modification of Duplex DNA with Ruthenium Donors and Acceptors, Angew. Chem. Int. Ed., England, Vol. 34, #3, pp. 352-354, 1995). Optionally, if the hybridization complex is unlabeled, detection may be accomplished by measurement of conductance differential between double stranded and non-double stranded DNA. Further, direct detection may be achieved by porous silicon-based optical interferometry or by mass spectrometry.
[0066] The label may be amplified, and may include for example branched or dendritic DNA. If the target DNA is purified, it may be unamplified or amplified. Further, if the purified target is amplified and the amplification is an exponential method, it may be, for example, PCR amplified DNA or strand displacement amplification (SDA) amplified DNA. Linear methods of DNA amplification such as rolling circle or transcriptional runoff may also be used.
[0067] The target DNA may be from a source of tissue including but not limited to hair, blood, skin, sputum, fecal matter, semen, epithelial cells, endothelial cells, lymphocytes, red blood cells, crime scene evidence. The source of target DNA may also include normal tissue, diseased tissue, tumor tissue, plant material, animal material, mammals, humans, birds, fish, microbial material, xenobiotic material, viral material, bacterial material, and protozoan material. Further, the source of the target material may include RNA. Further yet, the source of the target material may include mitochondrial DNA.
[0068] Base-stacking is dependent on the interactions of the ring structure of one base with the base ring of its nearest neighbor. The strength of this interaction depends on the type of rings involved, as determined empirically. While the applicants do not wish to be bound by any theory, among the possible theoretical explanations for this phenomenon are the number of electrons available between the two bases that participate in Pi bond interactions and the efficiency of different base combinations that exclude water from the interior of the helix, thereby increasing entropy. Although the above models are consistent with current data, the possible mechanisms of stacking interactions are not limited to these concepts.
[0069] It has also been observed that modification of bases involved in base-stacking interactions can strengthen Pi bonding, or stacking, between them. As one might predict from the models described above, these modifications provide more electrons for use in Pi bonding and/or an increase to the surface area of the rings, thereby increasing the area of hydrophobicity between the stacked bases. The current system can be modulated in a manner predicted by base-stacking theory and be used to predict additional changes for altering Pi electron behavior thereby underscoring that the mechanism of the invention may be dependent on the nature of Pi bonding between juxtaposed bases.
[0070] In addition to taking advantage of the naturally selected base-stacking interactions, it may be predicted that base modifications that increase the number of electrons in the ring or enlarge the hybdrophobic area would also increase discrimination of match from mismatch hybrids. Taking such information into account we have developed a novel SNP scoring method. It utilizes a combination of electronic-mediated nucleic acid transportation of an amplified target, passive heat denaturation of short fluorescent oligo reporters, and base-stacking energies. Sosnowski et al., Proc. Natl. Acad. Sci. USA, Vol. 94, pp. 1119-1123, (1997) have previously shown that charged DNA molecules can be transported, concentrated, and hybridized on a microchip by use of a controlled electric field. By taking advantage of an active microchip and base-stacking energies, we are able to efficiently target and analyze numerous SNPs with a high level of discrimination.
[0071] To demonstrate the efficacy of this new technique, we developed two model systems. The first is based on Hereditary Hemochromatosis, an autosomal recessive disorder that may lead to cirrhosis of the liver, diabetes, hypermelanotic pigmentation of the skin, and heart failure. The disease is linked to a G to A nucleotide transition at position 8445 in the HLA-H gene (Feder et al., J. Biol. Chem., Vol. 272, pp. 14025-14028, 1997). This locus was subsequently renamed HFE. The second assay centers on the Factor V gene. A mutation at position 1,691 (G to A substitution) leads to an increased risk of venous thrombosis (Bertina et al., Nature, Vol. 369, pp. 64-67, 1994). A SNP scoring methodology that offers both high throughput and cost effectiveness should allow implementation of routine tests for detecting individuals at risk for these, as well as other diseases that correlate to known SNPs, before disease onset. The utility of SNPs as genetic markers is therefore dependent, at least in part, upon the ability to provide accurate scoring of SNPs quickly. We have developed a novel scoring methodology, which fits these criteria.
[0072] Using an active microarray, we are able to miniaturize and accelerate the process of DNA transportation and hybridization. Moreover, the instrument in which the experiments are carried out is automated, which further streamlines this SNP scoring process. Further, this new methodology offers significant advancement in the fidelity of SNP scoring. We have accurately called every unknown sample tested, be it Hemochromatosis or Factor V. We have also successfully analyzed the Factor V SNP from each strand (FIG. 8 and FIG. 12), demonstrating the flexibility of the dual fluorescent base-stacking assay. It allows us to probe either strand, providing the opportunity to generate the most favorable (i.e., most energetic) stacking configuration. This ensures optimal discrimination.
[0073] A frequent problem in analyzing SNPs via conventional hybridization assays is the inability to call heterozygotes with 100% accuracy. Missing one of the two alleles can be as serious as a complete miscall. This problem usually arises when one of the allele-specific reporters (wild-type or mutant) is slightly more thermodynamically stable, often leading to ambiguous results.
[0074] By differentiating reporters based on both base-stacking energies and number of hydrogen bonds, we have been able to essentially normalize and enhance the stability of the correct reporters, thereby allowing easy discrimination between homozygotes and heterozygotes. On average, an amplified homozygote sample, such as for Hemochromatosis and Factor V, yields discrimination values greater than 15-fold between match and mismatch. In the 46 samples analyzed, the poorest discrimination for a homozygote was ˜6.3-fold. On the other hand, heterozygotes yielded ratios of approximately 1:1, and never more than 2:1. Since the discrimination values are so disparate between homozygotes and heterozygotes, it allows us to call homozygotes even if the amplification is biased towards one strand (see FIG. 11).
[0075] We initially chose Hemochromatosis and Factor V to be analyzed as each SNP has been linked to a specific and important disease (Feder et al., 1996 Supra; Bertina et al., 1994 Supra). Moreover, both conditions are relatively prevalent in society. A recent AACC bulletin report suggests that Hemochromatosis may be more prevalent than previously believed (American Association for Clinical Chemistry, Inc., Clinical Laboratory News, Vol. 25, number 2, pp. 16, February 1999). The use therefore of a methodology for early genetic testing of people at risk for these two afflictions should become an important tool in determining people that are heterozygous or homozygous for the mutant allele. This will allow early treatment, thereby improving quality of life.
[0076] We have demonstrated that SNP discrimination by the dual fluorescent base-stacking format works for two different genes. Moreover, we have determined that the method should function in a universal approach in that every possible mismatch for a reporter probe and target with respect to a stabilizer probe is distinguishable. (see Table 2). As shown each combination has strong discrimination values except for one combination. The one example showing a weak discrimination value (2.97) is of little consequence because the opposite strand combination can be substituted in an actual test case.
[0077] As a general description, this invention is best described in conjunction with FIG. 2. Initially, the sample containing a nucleic acid population representing one of or both wild type and mutant alleles is amplified with two primers, one being biotinylated (i.e., amplicon down format). Following the removal of salt, the amplification product 31 , with its biotinylated moiety, and the complementary strand 32 are diluted 1:2 in a final concentration of 50 mM histidine. This solution also contains 1 μM of stabilizer oligomer 33 . The stabilizer oligomer 33 is generally a 30-mer that is 100% complementary to both wild type and mutant alleles. This stabilizer directly abuts the polymorphism site on the target amplicon such that when a perfectly matched mutant reporter 34 or wild-type 35 is added to the system, base-stacking will be present.
[0078] Following introduction of the stabilizer, the reaction solution is heated to 95° C. for 5 minutes to allow the amplicon to denature. This sample, after cooling, is then electronically biased to the capture site of choice on an APEX type microchip. After biasing, the biotinylated amplicon strand 31 is attached to the microchip capture site via the biotin/streptavidin interaction with the permeation layer of the microchip. The 30-mer stabilizer oligomer 33 is hybridized to the amplicon strand 31 through hydrogen bonds.
[0079] The 30-mer stabilizer 33 effectively blocks the binding of the fully complementary nonbiotinylated amplicon strand 32 due the relative higher concentration of the stabilizer 33 (The stabilizer is at 1 μM concentration whereas the amplicon is generally between 500 pM and 5 nM).
[0080] Once the different amplicons (such as in a multiplex assay) have been electronically biased to their respective capture sites, reporting (using oligomers that are generally the probes that are labeled) is carried out. 1 uM of both wild type 35 and mutant 34 reporters (each identical with respect to 9 to 11 bases of the wild type with the terminal base, either 3′ or 5′, (or both), corresponding to either the mutant or the wild-type base) in 50 mM NaPO4/500 mM NaCl (high salt buffer) is allowed to incubate on the microchip for 3-5 minutes. Following incubation of the reporter probes 34 and 35, discrimination is achieved by heating the microchip about 4° C. below melting temperature of the perfectly matched reporter/amplicon in 50 mM NaPO4 (low salt buffer). Imaging is then performed using two different lasers, one corresponding to the fluorophore on the wild-type reporter and one to the fluorophore on the mutant reporter. From these signal intensities, backgrounds are subtracted and specific activities are taken into account. A ratio of wild type to mutant signal is achieved from which the allelic composition of the amplicon products are determined.
EXAMPLE I
[0081] a. Assay for the Discrimination of Single-Nucleotide Polymorphisms.
[0082] SNP scoring on an active matrix chip was accomplished as exemplified by the methodology illustrated in FIG. 2. The target was amplified with one biotinylated primer. A high concentration of 30-mer stabilizer oligo was added to the denatured amplicon and the mixture was electronically addressed to capture sites of interest on the array. Because DNA could be rapidly concentrated and hybridized, this process took place in a period as short as two minutes. The stabilizer oligomer was complementary to the biotinylated amplicon strand (the strand being probed). First, the stabilizer prevented the rehybridization of the complementary target amplicon strand thereby allowing the two allele-specific fluorescently-labeled reporter oligos access to the biotinylated strand. Second, along with the reporter oligos, it conferred base-stacking energy.
[0083] The stabilizer oligo was designed such that its 5′-terminus abutted the polymorphism of interest. The reporter oligos, one perfectly complementary to the wild type allele and one to the mutant allele, were designed such that their 3′-termini encompassed the polymorphism. When the stabilizer and reporter oligomers perfectly matched the target in an adjacently hybridized format, strong base-stacking energy phenomena were realized. In this system the reporters were 11 bp in length which provided excellent base-stacking differential signal between perfect matches and SNP mismatches, notwithstanding the results disclosed by prior researchers as mentioned above. Essentially, the mismatched reporter has one less nucleotide hydrogen bonded to its complement than the matched reporter. Upon stringent discrimination conditions, the perfectly matched reporter remains bound to its complement while the mismatched reporter readily dissociates.
[0084] In situations where the area of the target amplicon to be probed is closer to the 5′ end of the amplicon, the stabilizer can be designed to anneal to the amplicon at a position nearer the 3′ end of the amplicon thereby necessitating that the 3′-terminus of the stabilizer abut the polymorphism and the 5′-terminus of the reporter encompass the polymorphism.
[0085] b. The Stabilizer Oligo Enhances SNP Discrimination by Imparting Base-Stacking Energy.
[0086] To investigate the importance of employing stabilizer oligomers in this SNP scoring methodology, five unknown Factor V samples were analyzed in the presence or absence of the stabilizer probe. After electronically addressing the denatured target nucleic acid, the microchip was washed with 0.5×SSC, pH 12 to remove any rehybridized complementary strands. Stabilizer oligo was then electronically biased to capture sites for different time intervals to titrate their levels.
[0087] The wild type and mutant reporters, coupled to different fluorophores, were then passively hybridized to the target:stabilizer complex. This was followed by stringent discrimination achieved by increasing the temperature of a low salt wash buffer. Fluorescent signals were then measured at the two appropriate wavelengths to detect the wild type and mutant reporters. The results of this experiment are shown in FIG. 8. Discrimination values are given in Table 1.
TABLE 1 Role of stabilizer oligo on SNP discrimination. Sample no stabilizer 15″ stabilizer 30″ stabilizer 60″ stabilizer A 1:>100 1:>100 1:>100 1:>100 B 1:>100 1:>100 1:>100 1:47.7 C 1:3.31 1:1.55 1:1.44 1:1.53 D 3.51:1 10.1:1 16.2:1 13.9:1 E 3.73:1 8.63:1 10.7:1 12.9:1
[0088] (All discrimination values are reported as wild type signal intensity to mutant signal intensity.)
[0089] The significance of the stabilizer oligo can most clearly be shown for Sample C, a Factor V heterozygote. Column 5, which received no stabilizer, shows a clear mutant signal but essentially no wild type signal. Discrimination values were roughly 3.3:1 mutant to wild type. When compared with wild type samples (D and E), the discrimination value in the absence of stabilizer was almost identical, 3.5:1 and 3.7:1 wild type to mutant, respectively, making it essentially impossible to differentiate a Factor V heterozygote from wild type. In contrast, Sample C complexed with the most stabilizer oligo (column 4), was a clear heterozygote (1:1.5 mutant to wild type), while samples D and E were clear wild types (13.9:1 and 12.9:1, respectively).
[0090] These results demonstrate that base-stacking energies supplied by the abutment of the stabilizer and reporter can be used to enhance discrimination of reporter oligos that are either perfectly matched or mismatched by as little as one base pair. Moreover, the results indicate that mismatches involving more than one base pair (i.e., one at either end of the reporter) would equally be distinguishable.
[0091] The increased stabilization for perfectly matched complexes can also be demonstrated in the augmented signal intensities of samples that received more stabilizer oligo (compare Factor V mutant samples A and B, column 1 (least stabilizer) and column 4 (most stabilizer) FIG. 8). The discrimination values (Table 1) in the presence of stabilizer are excellent. The allelic makeup of all five unknown Factor V samples are unambiguous with A and B being homozygous mutant, C being a heterozygote, and D and E being homozygous wild type. All results were independently confirmed by allele-specific amplification.
[0092] To unequivocally illustrate that base-stacking energies are conferring the enhanced discrimination values, stabilizer oligomers to Hemochromatosis were designed such that a 1 bp or a 10 bp gap would exist between the stabilizer and reporter. These stabilizers were compared with the standard Hemochromatosis stabilizer that directly abuts the reporter. In this experiment, the stabilizer oligomers and sample, specifically a Hemochromatosis wild type, were concomitantly biased to duplicate capture sites. The results are shown in FIG. 9. In the case of no stabilizer (column 1), the initial wild type reporter signal is substantially reduced. The columns which received the standard stabilizer (column 2), the stabilizer leading to a 1 bp gap (column 4), and the stabilizer leading to a 10 bp gap (column 5), all had comparable initial signals. However, upon thermal discrimination, only the wild type reporter on the capture sites biased with the standard stabilizer remained, demonstrating that base-stacking energies were stabilizing the shorter reporter.
[0093] c. A Stabilizer Oligo Prevents Rehybridization of the Complementary Nucleic Acid Strand.
[0094] A difficulty in directing one strand of an amplification product following denaturation to a specific capture site of interest is that under most conditions the complementary strand will anneal back to its cognate partner. In an attempt to circumvent this problem, a high concentration of stabilizer oligomer was included with the amplification product during electronic addressing.
[0095] Various concentrations of Hemochromatosis stabilizer oligomer were combined with a wild type Hemochromatosis amplification product sample. These samples were compared to the identical wild type Hemochromatosis sample containing either no stabilizer oligomer or non-complementary nucleic acid. After initial biasing, the capture sites addressed without stabilizer were then re-addressed with a saturating level of stabilizer oligo. Capture sites initially targeted with amplicons plus stabilizer, were electronically addressed with buffer solution only. Reporter hybridization was carried out, followed by stringent washing. The final results are shown in FIG. 10.
[0096] In each case, high levels of discrimination were achieved. All permutations had a wild type to mutation ratio of greater than five-fold. However, signal on capture sites where stabilizer was simultaneously applied with amplification product, was significantly more robust. This suggests that the stabilizer bound to the biotinylated amplicon strand, and prevented the opposite amplified strand from rehybridizing. This result is somewhat surprising, since the amplification product hybrid (a 229-mer) would be expected to be much more stable than the stabilizer hybrid (a 30-mer). At equimolar ratios (approximately 1 nM), hybridization by the complementary amplicon strand would dislodge the bound stabilizer and block the reporter oligo from binding to the biotinylated strand. However, at higher molar ratios and the electronic conditions used in this assay, the stabilizer competes-out one strand of the amplicons. This result is also confirmed by the data in FIG. 9. Prediscrimination signals (initial) were substantially higher in the presence of a complementary stabilizer oligo, even one resulting in a gap between the stabilizer and reporter (compare columns 2, 4 and 5 to column 1).
[0097] d. Analysis of Unknown Hemochromatosis Samples.
[0098] Use of SNPs as genetic markers requires that their presence in a sample be accurately and quickly determined via a high throughput system. By taking advantage of an electric field to rapidly concentrate and hybridize nucleic acid, we are able to achieve discrimination results very efficiently. The accuracy of this SNP scoring method is demonstrated in the following experiment.
[0099] Sixteen unknown Hemochromatosis samples were amplified. Along with stabilizer oligo, each were electronically targeted to one capture site of a 25 site array. After allowing both wild type and mutant Hemochromatosis reporter oligos to passively hybridize to the amplified sample:stabilizer complex, stringent washing conditions were applied. The results, depicted in histogram form, are displayed in FIG. 11.
[0100] Assuming that a heterozygote should be roughly 1:1 wild type to mutant signal, it is clear that three of the unknown samples, 1, 7, and 12, were heterozygotes. Our criteria for calling a homozygote is that it should have at least five-fold more signal remaining from the perfectly matched reporter than the mismatched reporter. Following this criteria, it is easy to call samples 3, 4, 8, 9, 11, 13, and 16 as Hemochromatosis wild types and samples 2, 5, 6, 10, 14, and 15 as Hemochromatosis mutants. In fact, only sample 16 (˜6.3-fold) had a discrimination value of less than 15-fold. All results were independently confirmed by restriction analysis followed by gel electrophoresis. By discriminating SNPs using base-stacking energies, we have been able to correctly call 37/37 Hemochromatosis samples and 9/9 Factor V unknowns.
[0101] e. Analysis of Hemochromatosis and Factor V Samples on a Single Capture Site.
[0102] In another embodiment of the invention, throughput is increased for multiplex analysis of target sequences by electronically targeting more than one amplicon product to a single capture site. This both enhances the speed of the assay and increases the information yield of the microarray.
[0103] After amplification, we mixed together known Hemochromatosis and Factor V samples and their respective stabilizer oligos. Two such combinations were tested in quadruplicate. One contained a Hemochromatosis wild type and a Factor V mutant (FIG. 12, columns 1 and 2). The other contained Hemochromatosis and Factor V heterozygotes (FIG. 12, columns 4 and 5). Reporting and stringent washing was carried out first with Hemochromatosis reporters, followed by repeating the process with Factor V reporters. In each case, the results were as expected and easy to score. Since both set of reporters contained the same fluorophores, success of this multiplexing required complete removal of all bound Hemochromatosis reporters prior to the addition of the Factor V reporters. Note the complete lack of signal on the array after stripping, which was achieved by elevating the temperature in a low salt buffer.
[0104] The reason thermal discrimination was achieved at a much higher temperature for Factor V than previously shown (43° C. FIG. 12 vs. 32° C. in FIG. 8) is that the opposite strand was being interrogated. In this case, the Factor V reporters were significantly more GC rich, and thus, more thermally stable. By analyzing two PCR amplicons on a single capture site, we effectively double our throughput per unit time and per chip.
[0105] f. Universality of the Base-Stacked SNP Scoring Method.
[0106] We have successfully demonstrated that a SNP scoring method which takes advantage of electronic biasing and a reporter that is stabilized by base-stacking energies is indeed feasible. Besides the examples shown for Hemochromatosis and Factor V, we demonstrate that this assay can be applied universally to discriminate any SNP. Specifically, we designed a set of oligos around the Hemochromatosis polymorphism such that every possible base-stacking combination could be analyzed. The results from these experiments are compiled in Table 2.
TABLE 2 Universality of SNP discrimination by base stacking energies. Reporter a Stabilizer b A C G T A A c >100 d A 29.5 A >100 C 8.38 A C >100 C >100 G 43.8 G 7.98 A G 21.6 T >100 T >100 T 9.52 C A 51.6 A 40.3 A 89.9 C 8.85 C C 50.1 C 64.3 G >100 G 15.5 C G >100 T 34.6 T 86.8 T 37.0 G A >100 A 36.9 A 68.8 C 35.1 G C >100 C >100 G 26.2 G 24.8 G G 11.7 T 92.3 T 51.0 T 11.0 T A 10.1 A 22.0 A 37.9 C 15.6 T C 56.9 C >100 G 34.4 G 13.7 T G 2.79 T 51.9 T 28.5 T 6.46
[0107] In all cases but one, the discrimination between match and mismatch was greater than five-fold, and in most cases it was greater than 20-fold. This demonstrates that it is easy to differentiate homozygote wild type from homozygote mutant from heterozygote for any possible SNP, regardless of the polymorphism.
[0108] The one instance where this assay yielded poor discrimination (only 2.8-fold) was to be expected. The base-stacking was a 3′-T (stabilizer oligo) abutting a 5′-A (reporter oligo), the weakest of all base-stacking interactions (R. Sinden, DNA Structure and Function, Academic Press, Inc. 1994). Moreover, the mismatch on the target DNA was a G, a nucleotide known to form weak bonds with an opposing A. The non-optimal discrimination achieved here could easily have been overcome by analyzing the opposite amplicon strand.
EXAMPLE II
[0109] Besides the amplicon down format described in FIG. 2, a second format is useful wherein the stabilizer is anchored to specified capture sites (i.e., capture down format). As shown in FIG. 3, amplicon strands 90 and 91 may be denatured and combined with biotin labeled stabilizer oligo 92 . Additionally, further enhancement of signal may be derived from the inclusion of an “interfering” oligomer 93 designed to be complementary to the undesired amplicon strand.
[0110] Following addressing of the hybridization complexes to capture sites, anchored stabilizer annealed to allelic strands of the target, 90 and 90 ′ are probed with reporter oligos specific for wild type and mutant. In the figure, only one reporter is shown remaining following discrimination. Thus, as indicated in FIG. 3, the sample is homozygous for one allele.
[0111] This format has been successfully used for the detection of Hemochromatosis, Factor V, and EH1 mutations. In the preferred format, addressing of the amplicon occurs after denaturation. To prevent reannealing of the amplicon with its complementary strand at the capture site and to favor hybridization to the stabilizer probe, a specific interference oligonucleotide may be added to the protocol at the time of addressing to the capture site. This oligonucleotide is designed to be complementary to the undesired amplicon strand and should be present in molar excess. It should be designed to hybridize to the region outside of the stabilizer/reporter complementary region. In this way it will not interfere with hybridization of the stabilizer or reporter oligonucleotides to the desired amplicon. Rather, it will serve to “hold the amplicon open”, inhibiting reannealing of the amplicon with its complement. The interference oligonucleotide may be placed 5′ or 3′ to the base-stacked complex site.
EXAMPLE III
[0112] [0112]FIG. 4 sets forth a format wherein multiple SNP containing reporter probes are used with one another to provide multiple base-stacking energies. FIG. 4 a shows the capture down format while FIG. 4 b shows the amplicon down format. In FIG. 4 a , amplicon 42 is stabilized with stabilizer 41 that is anchored to a capture site via biotin moiety 40 , and two reporter probes 43 and 44 are hybridized to detect the presence of at least two SNPs. FIG. 4 b is similar except that the amplicon 45 is biotin labeled 40 ′ and anchored to the capture site while stabilizer 46 is unlabeled.
[0113] This format is useful where there are multiple closely spaced SNPs at a single genetic locus. An example of this is the Mannose Binding Protein gene locus that correlates with susceptibility to sepsis in leukopenic patients. In this case there are 4 SNPs spaced within 15 bases of each other. Another example is the human HLA locus in which there are a large number of naturally occurring variants scattered within 3 exons. In this format, the reporter probes are base-stacked against a stabilizer oligo and each of the reporters may be labeled with a different fluorophore specific for an allele that occurs at these sites.
EXAMPLE IV
[0114] [0114]FIG. 5 depicts a nested format wherein the target nucleic acid may be amplified using standard primers, one of which may be labeled (e.g., 52 ) for application of the amplicon down format. As shown, amplicons 50 ′ and 51 ′ may be denatured and mixed with stabilizer (and interfering oligo if desired) to yield stabilizer: amplicon hybridization complex ( 50 ″/ 56 / 51 ″). This complex is then addressed to a specified capture site followed by introduction of reporter probe 58 that benefits from base-stacking energies due to stabilizing interactions at both its 5′ and 3′ termini. Although only amplicon down format is illustrated, nested base-stacking can also be carried out using the capture down format.
[0115] This nested method is useful where there are multiple SNPs at a single genetic locus as described in EXAMPLE III as well as in situations where it is desired to detect SNPs from remote genetic loci. Moreover, this method is functional where it is desired to detect the presence of different and genetically unrelated amplicons whose coincident identification may provide useful information. Such information can be defined as “target-specific nucleic acid information” which provides some degree of identification of the nature of the target sequence. For example, a first region of a target nucleic acid may provide an amplicon used to identify the source of the nucleic acid (e.g., Staphylococcus vs. E. coli ). The second amplicon may be used to identify a particular trait such as antibiotic resistance (e.g., methicillin resistance). The nesting of the reporter using base-stacking energies to stabilize its hybridization indicates that both amplicons are present in the sample.
[0116] The nesting reporter may provide additional data where SNPs are additionally associated with one or the other or both of the genetic loci from which the amplicons were generated. An example of this is the identification of bacteria by polymorphisms within a conserved gene sequence, such as 16S rDNA, or gyrase A sequences. In each one of these amplicons there may not be sufficient genetic divergence to uniquely identify all species or subspecies. Thus, use of a second independent locus can provide essential data. For example, gyrase A is useful alone however, discrimination between closely related bacterial strains may be greatly augmented by inclusion of polymorphisms in the gyrase B or par C loci.
[0117] A unique feature of the nested method is the reporter probe may incorporate SNP or other specific bases at both its 5′ and 3′ termini. Thus, internal bases of the reporter oligo can be designed to incorporate unique sequence complementary to internal base positions of the stabilizer, while the terminal bases of the reporter may comprise bases specific to stabilizer, SNPs, or other bases of the different genetic loci.
[0118] [0118]FIG. 6 further depicts an additional aspect of the nested method wherein multiple reporters 63 may be nested to detect multiple SNPs that may be associated with either of the amplicon 60 and 62 , or 65 and 66 species. As with single reporter nesting, both the amplicon down and the capture down formats are applicable.
[0119] [0119]FIG. 7 further depicts a variation of the nested method wherein amplification of the target is carried out using SDA. In this situation, because the amplification primers incorporate nucleic acid sequence related to the amplification process (i.e., restriction endonuclease sequence), the termini of the amplicons hybridized to the stabilizer do not represent target-specific sequence. This creates the necessity for the stabilizer oligo to be designed such that SDA primer sequence abut a nesting reporter probe. Specifically, primers 70 and 71 specific for target locus 74 , and primers 72 and 73 for target locus 75 , each contain necessary restriction sites (e.g., Bso B1). Upon amplification, amplicons 74 ′ and 75 ′ are flanked by primer sequences 76 , 77 , and 81 , 82 respectively. Internal to theses flanking sequences may be located the specific SNP containing sequences of interest 78 , 79 , 83 , and 84 , which in turn flank target specific sequence 80 and 85 . This arrangement requires that the stabilizer oligo be designed to incorporate each of the above sequences in order to hybridize both amplicons and stabilizer into a complex. This additionally means that the stabilizer incorporates SNP sensitive sequence rather than the reporter oligo. Although capture down format is depicted, the amplicon format is equally applicable.
[0120] Following anchoring of the complex, reporter probe 87 is hybridized to the complex in a nested fashion. In this situation, the reporter may be designed to be stabilized where there is not any mismatches between the stabilizer and amplicon. In contrast, if mismatches were present, hybridization between the stabilizer and amplicon would necessarily result in a “bubble” formation allowing such mismatches to provide the destabilization necessary to keep the reporter from hybridizing.
[0121] In each of the above examples, base-stacking schemes are provided that achieve discrimination by breaking long regions of hybridization into two or more sequences. This methodology allows for discrimination of specific nucleic acid sequences from relatively short probes. The fact that short probes are used provides the opportunity to use detection mechanisms sensitive to both passive and electronic hybridization techniques. Moreover, the use of short probes provides the opportunity to use detection mechanisms based solely on the probe's mass (i.e., mass spectrometry) where extremely high levels of mass resolution are achieved by direct measurement (e.g. by flight or ESI). In such case, reporter probes having a length of 50 bases or less are preferred. Detection using mass spectrometry could be carried out by separating the probe from the hybridization complex and launching it directly to the mass spec detector.
[0122] Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity and understanding, it may be readily apparent to those of ordinary skill in the art in light of the teachings of this invention that certain changes and modifications may be made thereto without departing from the spirit or scope of the appended claims.
1
17
1
20
DNA
human
1
tgttatcaca ctggtgctaa 20
2
20
DNA
human
2
actacagtga cgtggacatc 20
3
30
DNA
human
3
taatctgtaa gagcagatcc ctggacaggc 30
4
11
DNA
human
4
gaggaataca g 11
5
11
DNA
human
5
aaggaataca g 11
6
19
DNA
human
6
tgaaggataa gcagccaat 19
7
19
DNA
human
7
ctcctctcaa cccccaata 19
8
30
DNA
human
8
ggctgatcca ggcctgggtg ctccacctgg 30
9
30
DNA
human
9
gggctgatcc aggcctgggt gctccacctg 30
10
30
DNA
human
10
cacaatgagg ggctgatcca ggcctgggtg 30
11
11
DNA
human
11
cacgtatatc t 11
12
11
DNA
human
12
tacgtatatc t 11
13
20
DNA
human
13
actacagtga cgtggacatc 20
14
20
DNA
human
14
tgttatcaca ctggtgctaa 20
15
30
DNA
human
15
ttacttcaag gacaaaatac ctgtattcct 30
16
11
DNA
human
16
cgcctgtcca g 11
17
11
DNA
human
17
tgcctgtcca g 11 | Methods are provided for the analysis and determination of the nature of single nucleic acid polymorphisms (SNPs) in a genetic target. In one method of this invention, the nature of the SNPs in the genetic target is determined by the steps of providing a plurality of hybridization complexes arrayed on a plurality of test sites on an electronically bioactive microchip, where the hybridization complex includes at least a nucleic acid target containing a SNP, a stabilizer probe having a sequence complementary to the target sequence and/or reporter probe, and a reporter probe having a selected sequence complementary to either the stabilizer or the same target sequence strand wherein a selected sequence of the reporter includes either a wild type nucleotide or a nucleotide corresponding to the SNP of the target. In accordance with the invention, the stabilizer, reporter and target amplicons are hybridized using electronic assistance of the microchip system such that base-stacking energies are utilized in discerning among other identifying indicators, the presence of wild type or polymorphism sequence. Applications include disease diagnostics, such as for the identification of polymorphisms in structural genes, regulatory regions, antibiotic or chemotherapeutic resistance conferring regions, or for SNPs associated with speciation or used for determination of genetic linkage. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is in the field of tools used for drilling oil and gas wells. Specifically, this invention applies to the drilling of a new well bore which branches off from an existing well bore which has been drilled and cased. This invention also applies to drilling through a cemented hole, followed by milling out a bridge plug or float equipment.
2. Background Information
It very often occurs that after a well bore has been drilled and the casing installed, a need arises to drill a new well bore off to the side, or at an angle, from the original well bore. The new well bore may be a lateral bore extending outwardly from the original vertical well bore. The process of starting a new well bore from the existing bore is often called "kicking off" from the original bore. Kicking off from an existing well bore in which metal casing has been installed requires that the casing first be penetrated at the desired depth.
Typically, a section mill or window mill is used to penetrate the metal casing, then the window mill and the drill string are withdrawn from the well bore. Following the milling of the window, a drill bit is mounted on the drill string, run back into the well, and used to drill the lateral well bore. Tripping in and out of the well bore delays the drilling process and makes the well more expensive to complete. The reason for using two different tools in spite of this is that the window mill must penetrate the metal casing, while the drill bit must penetrate the subterranean formation, which often contains highly abrasive constituents.
Similarly, when it is necessary to drill through a cemented hole, then mill away downhole metal items, two trips must be made. First, a drill bit is attached to the drill string, run into the hole, and used to drill through the cement. The drill string is then tripped out, the drill bit removed, and a milling tool is attached. The drill string is then run into the hole to mill away the bridge plug or other metal member.
Milling of metal requires a type of cutting insert which is formed of a material hard enough to cut the metal but durable enough to avoid excessive breakage or chemical deterioration of the insert. If the insert crumbles or deteriorates excessively, the insert will lose the sharp leading edge which is considered most desirable for the effective milling of metal. Both hardness and durability are important. It has been found that a material such as tungsten carbide is sufficiently hard to mill typical casing steel, while it is structurally durable and chemically resistant to exposure to the casing steel, allowing the insert to wear away gradually rather than crumbling, maintaining its sharp leading edge.
Drilling through a rock formation or cement requires a type of cutting insert which is formed of a material as hard as possible, to allow the insert to gouge or scrape chunks out of the rock or cement without excessive wear or abrasion of the insert. This permits the drilling operator to drill greater lengths of bore hole with a single drill bit, limiting the number of trips into and out of the well. It has been found that a material such as polycrystalline diamond is an excellent choice for drilling through a rock formation or cement, because of its extreme hardness and abrasion resistance.
Tungsten carbide is not as good as polycrystalline diamond for drilling through rock or cement, because the diamond is harder and will therefore last longer, limiting the number of trips required. Polycrystalline diamond is not as good for milling through metal casing as tungsten carbide, because the diamond is not as structurally durable, allowing it to crumble more readily and destroy the sharp leading edge. Further, polycrystalline diamond has a tendency to deteriorate through a chemical reaction with the casing steel. There is a chemical reaction between the iron in the casing and the diamond body, which occurs when steel is machined with a diamond insert. As a result of this chemical reaction, the carbon in the diamond turns to graphite, and the cutting edge of the diamond body deteriorates rapidly. This prevents the effective machining of the steel casing with diamond. Therefore, tungsten carbide is the better choice for milling through the metal casing, and polycrystalline diamond is the better choice for drilling through rock or cement.
Unfortunately, in both of these types of operations, use of each type of cutting insert in its best application requires that a first tool be used to perform a first operation, and that a second tool be used to perform a second operation. This means that two trips are required for the kickoff and drilling operation, or for the cement drilling and bridge plug milling operation. It would be very desirable to be able to perform a single trip operation, thereby eliminating at least one trip into and out of the bore hole.
BRIEF SUMMARY OF THE INVENTION
The present invention is a combination milling and drilling tool for use in performing a single trip milling-then-drilling operation. Similarly, a tool according to the present invention can be used in performing a single trip drilling-then-milling operation. The tool has a plurality of milling inserts suitable for metal milling, for performing the kickoff or milling operation, and a plurality of drilling inserts suitable for rock drilling, for drilling through the subterranean formation or cement. The milling and drilling types of cutting inserts are positioned relative to each other on the tool so that only the milling inserts contact the metal casing during the milling operation, and the drilling inserts are exposed to contact with the subterranean formation or cement, during the drilling operation. The specific embodiment discussed here will first deploy the milling inserts, followed by deployment of the drilling inserts. It is understood that, where drilling is required first, and milling second, the mounting locations of the two types of cutting inserts are simply swapped.
The milling insert can be formed of a relatively more durable material than the drilling insert, because it will need to maintain its sharp leading edge during metal milling. The drilling insert can be formed of a relatively harder material than the milling insert, because it will need to resist wear and abrasion during rock drilling. The milling insert can be formed of tungsten carbide, Al 2 O 3 , TiC, TiCN, or TiN, or another material hard enough to mill casing steel but relatively durable and chemically nonreactive with the steel. The drilling insert can be formed of polycrystalline diamond or another material of similar hardness, to facilitate drilling through a rock formation or cement.
The tool of the present invention employs a first cutting structure which is mounted in a fixed location on the tool body, and a second cutting structure which is movably mounted on the tool body. The second cutting structure is initially retained in a withdrawn position within the tool body, by retaining elements such as shear pins. A plurality of cutting inserts of a first type, suitable for the first phase of the operation, are mounted on the fixed cutting structure. A plurality of cutting inserts of a second type, suitable for the second phase of the operation, are mounted on the movable cutting structure. An actuator plug within the tool body is hydraulically moved from a first position to a second position, to move the movable cutting structure from its initial, withdrawn, position to a second, extended position, so that the second type of cutting inserts are moved downwardly and outwardly to come into play. A capture element retains the movable cutting structure in its deployed position.
The novel features of this invention, as well as the invention itself, will be best understood from the attached drawings, taken along with the following description, in which similar reference characters refer to similar parts, and in which:
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a longitudinal section view of the tool of the present invention, showing the movable cutting structure withdrawn into the tool body;
FIG. 2 is a longitudinal section view of the tool shown in FIG. 1, showing the movable cutting structure extended to its deployed position;
FIG. 3 is an end view of the tool of the present invention, showing the configuration in FIG. 1; and
FIG. 4 is an end view of the tool of the present invention, showing the configuration in FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, the combination milling tool and drill bit 10 of the present invention includes an upper body 12, a lower body 14, a hydraulic actuator plug 16, a plurality of fixed cutting blades 18, and a plurality of movable cutting blades 20. The upper body 12 can be threadedly attached at its upper end to a drill string. The lower body 14 is threaded onto the lower end of the upper body 12. The actuator plug 16 is slidably retained within a central cavity 15 in the lower body 14, with the actuator plug 16 being shown in its upper position in FIG. 1. The actuator plug 16 has a lower conical surface 17, which is angled with respect to the longitudinal axis of the tool 10.
The plurality of fixed cutting blades 18 are mounted around the periphery of the lower body 14, with each fixed blade 18 having a substantially vertical leading face upon which a first group of cutting inserts 36 are mounted. Where the tool will be used first for milling and then for drilling, the first group of cutting inserts 36 are milling inserts. The milling inserts can be formed of tungsten carbide, Al 2 O 3 , TiC, TiCN, or TiN, or another material hard enough to mill casing steel but relatively durable and chemically nonreactive with the steel. The plurality of movable blades 20 are shown in their initial, withdrawn, position, within slots in the lower body 14. Each movable blade 20 is retained in this initial position by a releasable retaining element such as a shear pin 56, shown in FIG. 2. Each movable blade 20 also has an inner edge 21 which is angled with respect to the longitudinal axis of the tool 10. A fixed end plug 22 is welded or threaded into the lower end of the lower body 14.
The slidable actuator plug 16 is held in its initial, upper, position by a shearable ring 24, which is held in its position by a circumferential groove 23 in the outer surface of the end plug 22. A longitudinal bore 26 in the upper body 12 is in fluid flow communication with a longitudinal bore 28 in the actuator plug 16, and with a longitudinal bore 30 in the end plug 22. One or more fluid ports 32 lead from the longitudinal bore 30 in the end plug 22 to the central cavity 15 within the lower body 14. A first plurality of fluid passageways 34 lead from the central cavity 15 to a first plurality of fluid ports 35 on the lower end face of the tool 10, just in front of the fixed cutting blades 18. When the actuator plug 16 is in its upper position shown in FIG. 1, the first plurality of fluid passageways 34 are uncovered, allowing fluid to flow from the work string via the longitudinal bores 26, 28, 30 and the central cavity 15, exiting the first plurality of fluid ports 35 to facilitate the cutting action of the fixed blades 18. A plurality of central fluid passageways 62 can be provided to conduct fluid to the central portion of the lower end of the tool 10, to further facilitate the cutting action of the fixed blades 18.
An upper body seal 38 seals between the outer surface of the upper end of the slidable actuator plug 16 and the upper body 12, when the actuator plug 16 is retained in the upper position. In this position, a capture ring 40 is held entirely within an inner capture ring groove 41 on the outer surface of the actuator plug 16. Upper and lower end plug seals 42, 43 are provided in circumferential grooves on the outer surface of the end plug 22. The upper end plug seal 42 seals between the end plug 22 and the longitudinal bore 28 of the actuator plug 16, when the actuator plug 16 is in the upper position. An outer capture ring groove 46 is provided in the central cavity 15 of the lower body 14.
As seen in FIG. 2, a ball 48 can be dropped through the drill string to pass through the longitudinal bore 26 of the upper body 12, and come to rest at the upper end of the actuator plug 16, blocking the longitudinal bore 28 of the actuator plug 16. Continued pumping of fluid through the drill string will build up pressure on the actuator plug 16 until it shears the shear ring 24 and moves downwardly to the lower position shown in FIG. 2. When the tool is used with a downhole mud motor, the drilling fluid pressure can be increased to a point which will shear the shear ring 24, without the necessity for dropping a ball. In either case, as the actuator plug 16 moves downwardly, its conical lower surface 17 abuts and exerts downward and outward force on the angled inner edges 21 of the movable blades 20. This shears the shear pins 56 holding the movable blades 20, and moves the movable blades 20 downwardly and outwardly in their respective slots 19. This downward and outward motion can be either purely translational motion as shown in FIGS. 1 and 2, or it can have a rotational component. The movable blades 20 can be prevented from falling out of their respective slots 19 by means such as abutting shoulders (not shown) on the blades 20 and slots 19. In this lower position of the actuator plug 16, the capture ring 40 snaps partially into the outer capture ring groove 46 in the lower body 14, and remains partially in the inner capture ring groove 41 in the actuator plug 16, to hold the actuator plug 16 permanently in the lower position. Upper and lower actuator plug seals 50, 52 seal between the outer surface of the actuator plug 16 and the central cavity 15 of the lower body 14, when the actuator plug 16 is in the lower position.
As seen in FIG. 2, each movable blade 20 has a substantially vertical leading face upon which a second group of cutting inserts 54 are mounted. Where the tool will be used first for milling and then for drilling, the second group of cutting inserts 54 are drilling inserts. The drilling inserts can be formed of polycrystalline diamond or another material of similar hardness, to facilitate drilling through a rock formation or cement. The dashed line 58 in FIG. 2 shows the position which was occupied by the inner edge 21 of the movable blade 20, when it was in its initial, withdrawn, position. By comparison of the dashed line 58 with the edge 21 in FIG. 2, it can be seen that the movable blade 20 has moved downwardly and outwardly to position the second group of cutting inserts 54 downwardly and outwardly beyond the first group of cutting inserts 36. This deploys the second group of cutting inserts 54 to commence their designed cutting action. When the tool 10 is designed for a milling-then-drilling application, this downward and outward motion of the movable blades 20 converts the tool 10 from a milling tool to a drill bit.
A second plurality of fluid passageways 60 lead from the central cavity 15 to a second plurality of fluid ports 61 on the lower end face of the tool 10, just in front of the movable cutting blades 20. When the actuator plug 16 moves to its lower position shown in FIG. 2, the second plurality of fluid passageways 60 are uncovered, allowing fluid to flow from the work string via the longitudinal bore 26 and the central cavity 15, exiting the ports 61 to facilitate the cutting action of the movable blades 20. Simultaneously, the actuator plug 16 blocks flow through the first plurality of fluid passageways 34.
FIGS. 3 and 4 illustrate the outward movement of the movable blades 20. FIG. 3 shows the movable blades 20 in their initial, withdrawn, position in their slots 19, corresponding to the configuration of the tool 10 shown in FIG. 1. It can be seen that the first group of cutting inserts 36 extend farther outwardly than the second group of cutting inserts 54. The dashed circle 64 represents the desired diameter of the borehole to eventually be drilled through the formation, after deployment of the second group of cutting inserts 54. FIG. 4 shows the movable blades 54 in their second, extended, position in their respective slots 19, corresponding to the configuration of the tool 10 shown in FIG. 2. It can be seen that the second group of cutting inserts 54 have extended beyond the first group of cutting inserts 36, to create the desired borehole diameter represented by the dashed circle 64.
While the particular invention as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages hereinbefore stated, it is to be understood that this disclosure is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended other than as described in the appended claims. | A combination milling and drilling bit which can be converted from a first type of cutting operation to a second type of cutting operation by hydraulically moving a plurality of movable blades to extend beyond a plurality of fixed blades. The fixed blades are dressed with cutting inserts suitable for the first type of cutting operation, while the movable blades are dressed with cutting inserts suitable for the second type of cutting operation. | 4 |
RELATED APPLICATIONS
This application claims priority, under 35 U.S.C. §119, to International Patent Application No.: PCT/PT2007/000048, filed on Nov. 15, 2007, which claims priority to Portuguese patent application No.: PT 103606, filed Nov. 15, 2006, the disclosures of which are incorporated by reference herein in their entireties.
TECHNICAL FIELD
The present invention relates to electro-optic sensors based on the Surface Plasmon Resonance (SPR) effect, in particular to processes and devices used for the detection of chemical and/or biological events comprising the following elements: (1) a radiation emitter ( 20 ) and a radiation detector ( 30 ); (2) a Detection Zone (DZ) ( 41 ) containing a Detection Surface (DS) ( 42 ) which incorporates a thin conductive layer built to allow for the occurrence of the SPR effect, for at least one angle of incidence and at least one wavelength of the radiation incident onto the DS ( 42 ); (3) a fluidic substrate ( 40 ) including channels ( 43 ) and at least one DZ described in (2); (4) a fluid control mechanism used to deliver a predefined fluid volume from an initial reservoir into a DZ and from there to a final reservoir; (5) a liquid crystal layer (LCL) ( 80 ), placed between the radiation emitter ( 20 ) and the radiation detector ( 30 ), controlled by electrical, magnetic or optical means, and used in such way that enables the control of the radiation properties and leading to an optimized SPR signal, improving in this way the accuracy and sensitivity of the detection device.
Chemical/Biological Detection Devices
A Chemical/biological detection device is composed by three major elements: (A) Recognition elements, capable of recognizing a specific chemical and/or biological substance; (B) Transduction mechanisms, capable of converting the chemical/biological recognition events into quantitative information; (C) Fluidic mechanisms, capable of delivering fluid samples to the recognition elements in a controlled manner.
(A) Recognition Element
Recognition elements are typically based on the key-lock principle, and comprise molecular regions or combinations of the same capable of recognizing specific chemicals or biological substances, from now on referred to analyte. There are different ways to achieve this effect, namely: randomly or oriented enzymes, lectines or antibodies. The performance of this recognition element is dependent on several parameters, namely: (i) the sensitivity (defined by the detection limit); (ii) the specificity (defined by the degree of sensitivity for detecting other substances present in the same medium of the specific analyte to be detected); (iii) its stability over time. In the case of chemical/biological detection devices used for determinations involving proteins or enzymes, the recognition elements usually consist of immobilized layers containing specific and oriented antibodies.
The chemical/biological recognition element may be obtained using several different mechanisms, namely: (i) chemical adsorption to the surface; (ii) encapsulation on a polymeric matrix; (iii) covalent bonding to a solid substrate. Although the choice of the chemical/biological recognition element is beyond the scope of the present invention, the description presented above serves only has a framework overview of the most common possibilities for building this biosensing element.
(B) Transduction Mechanism
There are several transduction mechanisms capable of converting chemical/biological events into quantitative information for subsequent treatment and analysis, namely electrochemical, vibratory, magnetic and optic transducers.
The optical detection of the SPR effect is essentially a measurement technique of the refractive index close to an electrically conductive surface. The most significant difference of SPR detection compared to conventional refractometers relates to the measurement scale and detection process: in conventional techniques, all the fluid volume contributes to the optical response which results in a average measure of the refractive index; On the contrary, in the case of SPR detection, only the volume of the fluid close to a conducting surface is relevant. Moreover, in this later case, the measure corresponds to a weighted average of the refractive index with a decaying weight when moving apart from the conductive layer in which the SPR effect occurs.
SPR Effect
The SPR effect is an optical phenomenon that results from the local charge density oscillation in an interface between two media of differing dielectric properties. In particular, the SPR effect occurs at the interface between a dielectric medium and a metallic one (see reference 1). In this case, the surface plasmon wave is an electromagnetic wave with polarization TM (magnetic vector of the wave is perpendicular to the propagation direction and parallel to the interfacial plan). The SPR propagation constant β may be described by equation (1):
β = λ ɛ m ɛ d ɛ m + ɛ d ( 1 )
in which λ is the incident wavelength, ∈ m is the dielectric constant of the metal (∈ m =∈ mr +i∈ mi ) and ∈ d is the dielectric constant of the dielectric medium. The SPR only occurs if ∈ mr <0 and |∈ m <∈ d . In this case, the SPR effect will propagate at the interface between the two media and will decrease exponentially from the interface to the bulk of each medium. On the other hand, the SPR effect is only detectable for metallic films with thicknesses in the range of tens to hundreds of nanometer (in the case of a gold film, the SPR effect typically occurs with thicknesses between 25 nm and 150 nm).
Due to these facts and according to equation (1), the propagation constant β of the SPR is extremely sensitive to variations of the refractive index in the dielectric medium close to the interface. As a consequence, the SPR effect may be exploited for sensing applications, e.g. the immobilization of a certain biological material (protein, enzyme, etc.) close to the interface will result in a local variation (at the nanometer length scale) of the refractive index (since typically the refractive index of water-based solutions is around 1.33 and the refractive index of biological compounds is close to 1.54). This change on the refractive index induces a change on the propagation constant of the surface plasmon that may be detected with precision by optical means, as described in the following sections.
SPR Configurations
There are three basic methods for detecting the SPR effect:
(i) Measuring the intensity of radiation reflected from the detection surface as a function of the radiation incidence angle; typically, for a given wavelength, the SPR effect is clearly detected at a specific incidence angle in which the reflection is minimal; (ii) Measuring the intensity of radiation reflected from the detection surface as a function of the radiation wavelength; typically, for a fixed incidence angle, the SPR effect is clearly detected at a specific radiation wavelength in which the reflection is minimal; (iii) Measuring the phase of radiation reflected from the detection surface as a function of the incidence angle or radiation wavelength. In this case, the SPR effect is clearly detected at a specific incidence angle or radiation wavelength in which the radiation phase variation is maximal.
Different optical configurations may be used in order to properly detect the SPR effect (see reference 2), using typically an optical system that both creates surface plasmon (using an illumination element, e.g. a laser or a radiation emitting diode or any other appropriate radiation source) and also detects the SPR effect (using an optical measurement element, e.g. CCD, CMOS, photodiode, or any other appropriate element).
The SPR effect only occurs if the component of the vector of incident wave that is parallel to the interfacial plane is coincident with the component of surface plasmon wave. This specific condition will only exist if there is some coupling mechanism typically provided by (i) a prism; (ii) a wave-guide; (iii) a diffraction grating. The man of the art may rapidly understand these coupling techniques by reading technical literature, namely by reading reference 1.
(C) Fluidic Mechanism
Different mechanisms may be used for the fluid control, namely conventional fluid pumping using external pumps and tubes, electro pressure control, acoustic/piezoelectric control, electrokinetics, and centrifugal control. The optimization of this element of chemical/biological detection device is beyond the scope of the present invention.
Liquid Crystal Layers
Liquid crystal (LC) phases, or mesophases, are intermediate phases between liquids and crystals, presenting orientation properties (see reference 3). A specific type of LC, named nematic LC, presents an order on the orientation of its molecules combined with a disorder on the position of its molecules. It is possible to define an average orientation direction of the LC molecules that propagates through long distances, with this direction defined, for example, by a certain alignment surface. Moreover, for certain LC molecules, it is possible to use an external electric field that also induces a specific orientation. In this case, the orientation of the LC molecules depends on the competition between the anchoring surface properties (induced by the alignment surface) and the coupling electric field forces (see reference 4).
The LC layers present two relevant properties:
(1) an optical anisotropy resulting in a mismatch on the radiation propagation through the LC layer, in terms of the radiation polarization parallel or perpendicular to the average orientation of the LC molecules; (2) a gradual change of the average orientation of the LC molecules along an LC layer induces changes on the polarization properties of the radiation passing through the LC layer. In particular, if the LC molecules present a twisting pitch along the LC layer that is much larger than the radiation wavelength, then the system will behave like a waveguide (in which the radiation polarization follows the rotation of the LC molecules). This is the basic principle of the standard LC devices according to the invention of M. Schadt (see reference 5). Now, if the twisting pitch of the LC layer is of the same order as the radiation wavelength, then smaller rotations of the radiation polarization will occur, and/or reflections and/or inverse radiation polarization rotations, depending on the wavelength/pitch ratio.
There are different types of LC layers with potential use for optical systems. The most common type of LC layer, called twisted nematic LC, is based on the continuous twisted orientation of the average direction of the LC molecules along the LC layer. The LC layer is characterized in that a twisting pitch depends on several parameters, namely the concentration of a chiral dopant that induces the twisting. When subject to an external electric field, the LC molecules tend to be aligned along the field and the twisting is then destroyed. By controlling the applied electric field it is possible to properly adjust the LC layer twisting pitch. For systems in which there is a need to maintain the optical quality (e.g., without radiation diffusion) some types of LC layers are no longer suitable (namely, PDLC layers, or other LC layers with significant radiation diffusion).
Conventional SPR Detection Devices
Conventional SPR detection devices include an optical system with pre-defined and fixed properties, namely in terms of incidence angles, polarization and wavelength.
FIG. 1A is a schematic illustration of a conventional SPR detection device according to the prior art, in the prismatic configuration. A radiation emitter ( 20 ) produces a radiation beam ( 101 ) focused through a prism ( 90 ) into a detection surface DS ( 42 ) situated in a detection zone DZ ( 41 ). The DS includes a thin conductive layer in close proximity with the fluid. The radiation reflected ( 102 ) is directed to the radiation detector ( 30 ). The analysis of the radiation signal observed in the radiation detector ( 30 ) is used for the quantitative measurement of the concentration of substances or of chemical and/or biological events occurring in the vicinity of the DS ( 42 ). In this configuration, the device presents fixed and predefined optical properties, namely in terms of radiation wavelengths, phase and incidence angles.
FIG. 1B is a schematic illustration of a conventional SPR detection device according to the prior art, in the grating coupling configuration. A radiation emitter ( 20 ) produces a radiation beam ( 101 ) focused through a prism ( 90 ), into a detection surface DS ( 42 ) situated in a Detection Zone DZ ( 41 ). The DS includes a thin conductive layer behaving like a diffraction grating. The radiation reflected ( 102 ) is directed to the radiation detector ( 30 ). The analysis of the radiation signal observed in the radiation detector ( 30 ) is used for the quantitative measurement of the concentration of substances or of chemical and/or biological events occurring in the close proximity of the DS ( 42 ). Again, in this configuration, the device presents fixed and predefined optical properties, namely in terms of radiation wavelengths, phase and incidence angles.
In this configuration, the radiation emitter ( 20 ) has fixed and pre-defined optical properties, namely in terms of:
the wavelength spectra, this parameter may be pre-defined by using a laser for the radiation emitter ( 20 ), or by using a radiation emitter ( 20 ) with a continuous emission spectra, such as a LED or any other source of continuous spectra; the range of incident angles of the radiation incident on the DS ( 42 ), defined by the optical elements used, namely by the optical lenses setup the radiation emitter ( 20 ); the polarization of the incident radiation, typically fixed linear or circular, when using lasers in the radiation emitter ( 20 ), or non-polarized radiation when using LEDs; the phase of the incident radiation. If a laser is used for the radiation emitter, typically the radiation is coherent in the radiation cone incident on the DS ( 42 ); the focal point of the radiation incident on the DS ( 42 ); the refractive index of the material used as substrate in contact with the DS ( 42 ); the refractive index of the standard fluid used to perform the SPR measurements.
These different parameters are pre-defined and fixed in conventional SPR detection devices, and this fact presents a limitation on their potential use. In particular, it is a limiting factor in terms of detection range of the fluid refractive index in contact with the DS ( 42 ). Moreover, the limitations, associated with detection noise and angular resolution of the radiation detector ( 30 ) sensor (i.e. the relation between angular aperture of the incident radiation and number of detection elements in the sensor), are also a limiting factor of the resolution and sensitivity of conventional SPR detection devices.
These facts limit both the sensitivity and the application range of SPR detection. In particular, conventional SPR detection devices present the following limitations:
(1) difficulty in eliminating optical defects (mechanical fatigue, radiation diffusion, refractive index changes), resulting in a noise signal higher than desired. This fact is particularly relevant when detecting small biological substances; (2); difficulty in distinguishing the SPR sensor signal due to receptor-analyte binding and refractive index changes of either the fluid or the DS ( 42 ) substrate due to temperature changes. This fact limits the extrapolation of SPR measurements into quantitative information regarding analyte concentration present near the DS ( 42 ) (see reference 6); (3) difficulty in adjusting the detection parameters for maximum sensitivity at the DS ( 42 ) for the desired thickness corresponding to the size of the analyte;
In order to overcome these limitations, the present invention considers the use of a LC layer ( 80 ) placed between the radiation emitter ( 20 ) and the radiation detector ( 30 ), controlled by electric, magnetic or optical means, in order to adjust the radiation properties and in this way amplify the SPR signal observed at the radiation detector ( 30 ).
The patent US2003103208 refers to a SPR sensor with a prismatic configuration, using an LC layer placed between the radiation emitter and a conductive layer defining the DS, in order to rotate the radiation polarization by 90°. In this case, the radiation incident on the DS may have two polarization states: (i) TM polarization (parallel to the interface) or (ii) TE polarization (perpendicular to the interface). The patent mentioned above only applies to SPR sensors in the prismatic configuration and to devices wherein the radiation polarization is rotated by 90°.
The patent EP1157266 refers to an SPR detection device, mentioning that it would be possible to use a LC layer behaving like a controllable polarizer. The referred patent applies to SPR sensor devices based on diffractive reflective optical elements. Moreover, in the above-mentioned patent there is no mention on the possible embodiment of the referred LC layer.
Patents EP1068511 and US2003206290 concern an SPR detection device in which LC layers are used as controllable diaphragms by electric means, in order to select the time period and placement of the radiation beam necessary for the SPR effect.
The following publications are included here for reference:
1. Homola, J. Et al. Sensors and Actuators 54, 3-15 (1999); 2. Homola, J. Anal Bioanal Chem 377, 528-539 (2003); 3. P. G. de Gennes, J. Prost, The Physics of Liquid Crystals (2nd ed. Clarendon, Oxford 1993) 4. Fonseca, J G, PhD Thesis, Strasbourg 2001 5. Helfrich, W., Schadt, M. patent CH19710005260 6. G. Vertogen, W. H. de Jeu: Thermotropic Liquid Crystals: Fundamentals (EPSinger-Verlag, Berlin, 1988) 7. Hecht, E. Optics, Addison Wesley Longman (1998). 8. Gordon D. Love. Proc. Soc. Foto.-Opt. Instrum. Eng. 2566: 43-47 (1995). 9. H. Ren et al, Appl. Phys. Lett. 84, 4789 (2004). 10. Born, M. and Wolf, E. Principles of Optics: Electromagnetic Theory of Propagation, Interference, and Diffraction of Light, Pergamon Press (1989).
OBJECT OF THE PRESENT INVENTION
We have come to the conclusion that it would be relevant to dynamically adjust some parameters significant for the SPR effect, in order to optimize the respective SPR detection device performance. In this frame, LC layers are found to be appropriate and advantageous, since it is possible to adjust the radiation properties (reflected radiation or transmitted radiation) by controlling a LC layer using simple electric or optic means. This adjustment of the radiation properties, when coupled to a detection device based on the SPR effect, may be explored in order to enhance its overall performance.
In a first aspect, the present invention comprises an optical system consisting of a radiation emitter ( 20 ) and a radiation detector ( 30 ) both used for detecting events occurring in the close proximity of a DS ( 42 ), which includes a thin electrically conductive layer in a fluidic substrate, containing channels ( 43 ) and at least a DZ ( 42 ). The DZ ( 42 ) is built in such a way that it enables the occurrence of the SPR effect, which is used for the detection of chemical and/or biological events. The detection device also includes a LC layer ( 80 ) placed in between the radiation emitter ( 20 ) and the radiation detector ( 30 ), controlled by electrical or optical means. The LC layer ( 80 ) is controlled in such a way that enables the controlled adjustment of the radiation properties in order to optimize the accuracy and sensitivity of the detection device.
In a second aspect, the present invention consists of a SPR sensor ( 10 ) capable of detecting chemical and/or biological events in the close proximity of a DS ( 42 ), comprising a fluidic substrate ( 40 ) and an optical system, wherein the optical system comprises a radiation emitter ( 20 ) and a radiation detector ( 30 ) and a LC layer ( 80 ) placed in the radiation path between the radiation emitter ( 20 ) and the radiation detector which is capable of adjusting the radiation properties. The SPR sensor ( 10 ) is capable of detecting:
(i) the presence of a specific substance, and/or (ii) the occurrence of a specific chemical and/or biological event in one of the detection zones of the fluidic substrate,
The arrangement of the radiation emitter ( 20 ) and radiation detector ( 30 ) with respect to the fluidic substrate ( 40 ) is fixed in such a way that the radiation beam incident on the DS ( 42 ) contains at least one incident angle for which there is a coupling on the thin electrically conductive layer resulting in the SPR effect. This configuration is influenced by several properties and parameters, in particular:
The wavelength of the radiation incident on the DS ( 42 ); The refractive index, extinction coefficient and thickness of the electrically conductive layer; The incidence angle; The radiation polarization; The refractive index and extinction coefficient of the fluid present at the DZ ( 41 ).
In this sense, and having all parameters fixed, it is possible to observe a change in the radiation pattern of the SPR sensor ( 10 ) and from this information to quantify the change on the refractive index in the close proximity of the DS ( 42 ). This determination is then used in order to quantify the surface immobilization of a certain substance or the reaction of two types of molecules in the proximity of the DS ( 42 ).
The embodiments of the present invention enable proper adjustment of the different parameters mentioned above, in a dynamic way and during the detection process, by using an additional LC layer ( 80 ), also placed in the radiation path between the radiation emitter ( 20 ) and the radiation detector ( 30 ). The different embodiments described in the following sections correspond to different solutions for existing problems of conventional SPR detection devices.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a schematic illustration of a conventional SPR detection device according to the prior art, in the prismatic configuration.
FIG. 1B is a schematic illustration of a conventional SPR detection device according to the prior art, in the grating coupling configuration.
FIG. 2A is a schematic illustration of the average orientation of the molecules in a twisted nematic LC layer. In the rest condition the molecules present a rotation of 90° along the LC layer (left) and when subject to an external electric field above a certain threshold (V_th) the twist is minimized and the molecules became aligned along the electric field (right).
FIG. 2B is a schematic illustration of the behaviour of the total twisting angle of the LC layer illustrated in FIG. 2A as a function of the applied voltage, for high enough voltages the twisting angle tends to zero.
FIG. 3A is a schematic illustration of a SPR detection device in the grating coupling configuration and using a LC layer to control the polarization of the radiation incident in the detection surface.
FIG. 3B is a schematic illustration of the embodiment of the device described in FIG. 3A , after acquiring two signals (S 1 and S 2 ) with different polarizations being possible to minimize the acquisition noise by dividing the two signals and obtain a final signal (S_SPR) with optimized signal to noise ratio.
FIG. 4A is a schematic illustration of the behaviour of SPR effect in terms of radiation intensity (dashed line) and radiation relative phase (solid line) both as a function of the incidence angle on the detection surface.
FIG. 4B is a schematic illustration of the average orientation of the molecules in a uniform nematic LC layer. In the rest condition, the molecules average orientation is uniform and aligned along the alignment surface direction (left), and when subject to an externally applied electric field above a certain threshold (V_th) the molecules become aligned with the electric field.
FIG. 4C is a schematic illustration of the behaviour of the total phase difference (de-phasing between the ordinary and extraordinary polarization directions of the radiation with respect to the LC average orientation direction) of the LC layer described in FIG. 4B as a function of the applied voltage. For high enough voltages the phase difference tends to zero.
FIG. 5A is a schematic illustration of an SPR detection device in the grating coupling configuration and according to the second example of the present invention, where a LC layer is used to control the de-phasing of the radiation incident on the detection surface.
FIG. 5B is a schematic illustration of the evolution of the de-phasing of radiation as a function of the incidence angle on the detection surface for the detection device described in FIG. 5A .
FIG. 5C is a schematic illustration of the SPR signal detected by the radiation detector of a conventional SPR sensor (dashed line) and the sensor for the device described in FIG. 5A (solid line)
FIG. 5D is a schematic illustration of the evolution of the distance between the two angles at which the minimum of intensity of the SPR optical signal occur (W), as a function of the de-phasing of radiation for the detection device described in FIG. 5A , and in which the LC layer ( 80 ) induces a de-phasing perpendicular to the incidence direction.
FIG. 6 is a schematic illustration of the optical sub-system of radiation emission for a SPR detection device according to the present invention, in which a collimating lens is positioned after the emitter, followed by a polarizer and an LC layer placed in the collimated radiation path, and finally a focusing lens is used for directing the radiation to the detection surface.
FIG. 7A is a schematic illustration of the resulting refractive index of the LC layer described in FIG. 4B as a function of the applied voltage.
FIG. 7B is a schematic illustration of the average orientation of the molecules inside the LC layers. In the rest condition (V<V_TH) the LC molecules present uniform average orientation (left). Depending on the applied voltage (for V>V_TH), it is possible to create spatial patterns of refractive index.
FIG. 7C is a schematic illustration of the equivalent focal distance of the LC layer illustrated in FIG. 7B , as a function of the applied voltage.
FIG. 7D is a schematic illustration of the optical sub-system of radiation emission for a SPR detection device according to the present invention, in which a group of two LC layers are used to act as focusing lens of variable amplification with constant focal length.
FIG. 8 is a schematic illustration of a detection device according to the present invention, in which a group of two LC layers is placed in between the detection surface and the radiation detector in order to control the radiation signal amplification.
DETAILED DESCRIPTION OF THE INVENTION
In a first aspect, the present invention consists of an SPR sensor ( 10 ) used for detecting chemical and/or biological events, comprising a radiation emitter ( 20 ) and a radiation detector ( 30 ) used for detecting events occurring in the close proximity of a DS ( 42 ) of a DZ ( 41 ) of a fluidic substrate ( 40 ), comprising channels ( 43 ), and at least one DZ ( 41 ). The DZ ( 41 ) contains a DS ( 42 ), which includes a thin electrically conductive layer, built in such a way that enables the occurrence of the SPR effect. The SPR sensor ( 10 ) includes a LC layer ( 80 ), positioned in the radiation path between the radiation emitter ( 20 ) and the radiation detector ( 30 ), and controlled by electrical or optical means, enabling the proper adjustment of the radiation properties, to optimise the SPR optical signal. The proper adjustment of the radiation properties using the LC layer ( 80 ) leads to enhanced sensitivity and accuracy of the SPR detection device.
In a second aspect, the present invention consists of a SPR sensor ( 10 ) capable of detecting chemical and/or biological events occurring in the close proximity of a DS ( 42 ), comprising a fluidic substrate ( 40 ) and an optical system, wherein the optical system comprises a radiation emitter ( 20 ) and a radiation detector ( 30 ) and an LC layer positioned between the radiation emitter ( 20 ) and the radiation detector ( 30 ). The LC layer ( 80 ) is capable of adjusting the radiation properties.
The SPR sensor ( 10 ) is capable of detecting:
(i) the presence of a specific substance, and/or (ii) the occurrence of a specific chemical and/or biological event in one of the detection zones.
The embodiments of the present invention enable proper adjustment of the different parameters mentioned above, in a dynamic way and during the detection process, by using an additional LC layer ( 80 ), positioned in the radiation path between the radiation emitter ( 20 ) and the radiation detector ( 30 ). The different embodiments described in the following correspond to different solutions for existing problems of conventional SPR detection devices.
FIRST EXAMPLE
The SPR effect occurs in the component of the radiation polarization that is parallel to the interface (TM polarization) between a thin electrically conductive layer and a dielectric layer. Conventional SPR sensors typically maximize the intensity of the incident radiation in this polarization in order to maximize the SPR signal. The absence of a reference signal is considered problematic for the detection. In particular, the lack of reference signal results in a high (higher than desired) signal noise, due to different sources, namely the lack of stability and uniformity of the radiation source and of the substrate used for the detection. One simple way to eliminate this problem consists in rotating, in a controlled and systematic way, the polarization of the incident radiation. Since the noise is, in a first analysis, independent of the radiation polarization, one may then eliminate a significant part of the acquisition noise by acquiring two signals of different polarizations. For example, by acquiring two signals with TE and TM polarizations and dividing (TM/TE) or subtracting (TM−TE) the two signals it is possible to isolate only the contribution of the SPR effect. This process may the performed using a LC layer ( 80 ) with well-known properties.
FIG. 2A is a schematic illustration of the average orientation of the molecules in a twisted nematic LC layer. In the rest condition (V<Vth) the average orientation of the LC molecules ( 83 ) present a rotation of 90° along the LC layer (left). For sufficiently high applied voltages (V>Vth) the LC molecules ( 83 ) tend to be aligned along the electric field and the twist is gradually minimized.
FIG. 2B is a schematic illustration of the behaviour of the total twisting angle of the LC layer described in FIG. 2A , as a function of the applied voltage. If the twisting pitch is sufficiently large when compared with the electromagnetic radiation wavelength, then the LC layer ( 80 ) behaves like a wave-guide, so that the incident radiation polarization is rotated along the LC rotation.
Using, for example, a LC layer ( 80 ) with a twisting pitch of eight times its thickness, the LC layer ( 80 ) will then show two typical states depending on the applied voltage:
(i) when the applied voltage is sufficiently low (e.g., for a planar orientation, the applied voltage is below the Frederiks threshold, see reference 3) then the LC layer ( 80 ) induces a rotation of 90° of the incident radiation polarization. The incident radiation may then be selected and aligned in order to have a 90° rotation of its polarization when passing through the LC layer ( 80 ) and then be incident on the DS ( 42 ) with the TM or TE polarizations while maintaining its relative intensity; (ii) when subjected to a sufficiently high voltage, the rotation of the LC molecules ( 83 ) is destroyed as they tend to be aligned with the applied electric field. In this case, the radiation incident on the DS ( 42 ) will only have one polarization component (e.g. TM).
The novelty of the present invention consists of a device comprising:
(i) a fluidic substrate ( 40 ) including at least one DZ ( 41 ) with a DS ( 42 ) built in such a way that it enables the occurrence of the SPR effect; (ii) a group of radiation emitter ( 20 ) and radiation detector ( 30 ) arranged in such a way that the radiation incident onto the DS ( 42 ) includes a range of angles in which the SPR effect occurs; (iii) a LC layer ( 80 ) positioned in the radiation path between the radiation emitter ( 20 ) and the radiation detector ( 30 ) built in such a way that it behaves like a wave-guide, so that the polarization of radiation passing through the LC layer ( 80 ) is also rotated, enabling the SPR sensor 10 to accomplish the following sequence of events. (1) Reference Tension Control. The LC controller ( 84 ) applies a sufficiently low voltage on the LC layer ( 80 ) so that the LC molecules ( 83 ) impose a rotation of the polarization of radiation incident on the DS ( 42 ). (2) Reference Signal Acquisition. The first signal S 1 is acquired by the radiation detector ( 30 ) corresponding to a condition in which the two polarization components (TE and TM) are present in the radiation incident on the DS ( 42 ). The acquisition of the signal S 1 must occur after a certain time from the applied reference tension (typically in the order of ms) in order to have all the LC molecules out of the transitory orientation regime. (3) Tension Measurement Control. The LC controller ( 84 ) applies a sufficiently high voltage on the LC layer ( 80 ) so the LC molecules ( 83 ) are aligned with the applied electric field destroying the natural twisting. Due to this alignment, there is no rotation of the polarization of radiation incident on the DS ( 42 ). (4) Signal Measurement Acquisition. The second signal S 2 is acquired by the radiation detector ( 30 ) that corresponds to a condition in which only one polarization component (e.g. TM) is present in the radiation incident on the DS ( 42 ). The acquisition of the signal S 2 must occur after a certain time from the applied reference tension (typically in the order of ms) in order to have all the LC molecules out of the transitory orientation regime. (5) Signal Processing. Finally the SPR signal is extracted from the two optical signals using the relation:
S
SPR
=
S
2
2
S
1
-
S
2
(
2
)
FIG. 3A is a schematic illustration of a SPR detection device ( 10 ) in the grating coupling configuration and using a LC layer ( 80 ) to control the polarization of the radiation incident in the DS ( 42 ). The radiation emitter ( 20 ) irradiates a light beam ( 101 ) incident on the LC layer ( 80 ) that presents in its initial state a total twist of 45° of the average orientation of the LC molecules ( 83 ). The LC layer ( 80 ) presents a large twisting pitch when compared to the radiation wavelength behaving like a wave-guide. The LC layer ( 80 ) is connected to controller ( 84 ) able to apply electric tensions and in this way fine-tune the total twist of the incident radiation polarization ( 101 ) on the DS ( 42 ). Analyzing the signals detected on the radiation detector ( 30 ) corresponding to the different applied voltages, enables the determination of real-time reference signals, eliminating in this way a significant part of the SPR signal acquisition noise. After passing the LC layer ( 80 ), the radiation beam is transmitted over a transparent substrate ( 44 ) and is incident on the DS ( 42 ) that includes a thin electrically conductive layer behaving like a diffraction grating. The DS ( 42 ) is in direct contact with a fluid. The reflected signal ( 102 ) is then incident on the radiation detector ( 30 ). From the analysis of the optical signals on the radiation detector ( 30 ) it is possible to quantitatively determine the concentration of the analyte in the close proximity of the DS ( 42 ).
FIG. 3B is a schematic illustration of the embodiment of the device described in FIG. 3A . An initial signal S 1 , corresponding to a linear polarization of the incident radiation ( 101 ) at 45° (with respect to the TM polarization direction) contains a significant optical noise that prevents a precise measurement. By applying the proper electric voltages to the LC layer ( 80 ) it is possible to obtain a second optical signal S 2 , corresponding to the TM polarization of the incident radiation ( 101 ) (0°). This second signal still contains a significant noise level. By properly dividing both signals one determines the SPR signal and eliminates almost all the noise, since this noise is mostly polarization-independent.
One should note that this concretization only enables the proper measurement of the SPR effect if the delay between the two signals S 1 and S 2 is small compared to the dynamics of the acquisition noise, since this approach is only valuable for polarization-independent noise.
The radiation incident ( 101 ) on the LC layer ( 80 ) should preferably be collimated in order to have a uniform and constant rotation of the radiation polarization. In this case, the optical elements used for focusing the radiation incident on the DS ( 42 ) should be placed between the LC layer ( 80 ) and the fluidic substrate ( 40 ) that contains the DS ( 42 ). Alternatively, the man of the art may place the LC layer ( 80 ) in a region in which the radiation is not collimated, as long as the dependency of the polarization rotation as a function of the incident angle is taken into account. This example may easily be extended to other similar situations wherein the rotation of the LC layer is smaller or higher than 45°, or if the polarization of the incident radiation is different. As a general rule, the SPR signal S_SPR is obtained from the relation:
S SPR = a 1 S 2 b 1 S 1 - c 1 S 2 ( 3 )
in which a 1 , b 1 and c 1 are parameters that depend on the initial rotation angle of the LC molecules ( 83 ), on the total initial twist of the LC layer ( 80 ), its thickness and the applied electric voltages.
Other methods for controlling the LC layer ( 80 ) may be considered, as long as it is still possible to control the degree of rotation of the LC molecules ( 83 ). For example, is it possible to use a magnetic actuator, and in this case one must consider that typically LC molecules tend to align perpendicularly to the direction of the applied magnetic field. One may also consider a variation of the present embodiment, in which the LC controller ( 84 ) keeps the electric voltage amplitude constant and only the electric signal frequency is varied. In this case the man of the art must select the proper frequency range in which the LC molecules response is strongly dependent of the applied electric signal frequency.
SECOND EXAMPLE
Conventional SPR detection devices based on the detection of reflected radiation intensity are based on the measurement of radiation intensity levels of the reflected radiation as a function of the incidence angle. In this case, the SPR effect is clearly identified by a strong decrease of the reflected radiation intensity for a specific incidence angle. So the SPR detection is based on the determination of the temporal evolution of the reflected radiation minimum. In an alternative approach, it is possible to measure the variation of the relative phase of the reflected radiation, since this latter shows a much sharper transition in the SPR effect than the transition observed in radiation intensity, as illustrated on FIG. 4A .
FIG. 4A is a schematic illustration of the behaviour of SPR effect in terms of radiation intensity (dashed line) and radiation relative phase (solid line) both as a function of the incident angle on the DS ( 42 ). The relative phase shows a much sharper transition at the SPR coupling than the radiation intensity. This fact may be explored in order to build SPR detection devices with better resolution.
Although there are intrinsic advantages in the phase-measurement configuration, its implementation in conventional SPR detection devices is particularly difficult. On the other hand, it is possible to use a LC layer ( 80 ), built in such a way that it enables the proper adjustment of the radiation de-phasing, according to FIGS. 4B and 4C .
FIG. 4B is a schematic illustration of the average orientation of the LC molecules ( 83 ) in a uniform nematic LC layer ( 80 ). Due to the anisotropic nature of the LC molecules a de-phasing between the TE and TM polarization components of the radiation is observed. In the rest condition (V<Vth) the molecules average orientation is uniform and parallel to the surface, and when subject to sufficiently high external electric fields (V>Vth) the LC molecules ( 83 ) tend to be aligned along the electric field.
FIG. 4C is a schematic illustration of the behaviour of the total phase difference (de-phasing between the ordinary and extraordinary polarization directions of radiation with respect to the LC average orientation direction) of the LC layer ( 80 ) described in FIG. 4B as a function of the applied voltage. For sufficiently low voltages (V<Vth) and due to the optical anisotropy the total de-phasing of the LC molecules is fixed and defined by the total LC layer ( 80 ) thickness and the average orientation of the LC molecules ( 83 ). For high enough voltages (V>Vth) the phase difference tends to zero and is defined by relation (4).
Knowing the properties of the LC layer ( 80 ) it is then possible to determine with precision the induced de-phasing δ by the relation:
δ = n o ∫ - d / 2 d / 2 [ n e n o 2 sin 2 θ ( z ) + n e 2 cos 2 θ ( z ) - 1 ] ⅆ z ( 4 )
in which n o and n e are the ordinary and extraordinary refractive indexes of the LC and θ(z) is the average orientation of the LC molecules ( 83 ) along the LC layer ( 80 ).
In this example, we have considered a SPR sensor ( 10 ) with fixed wavelength and a range of incidence angles, and having a LC layer ( 80 ) placed in the radiation path between the radiation emitter ( 20 ) and the radiation detector ( 30 ). The SPR sensor ( 10 ) enables the detection of radiation intensities as a function of the incidence angle, the LC layer ( 80 ) being built and placed in such a way that it enables the adjustment of the optical phase difference between the TM and TE components of the radiation polarization through optical or electric means.
FIG. 5A is a schematic illustration of an SPR detection device in the grating coupling configuration according to this second embodiment of the present invention. The radiation emitter ( 20 ) irradiates a light beam that passes through an LC layer ( 80 ) presenting in its rest condition a phase variation between the TM and TE components of the radiation polarization, given by δ=Δn*D, in which Δn is the birefringence of the LC and D the total thickness of the LC layer ( 80 ). The LC layer ( 80 ) is connected to an LC controller ( 84 ) that enables to control the electric voltages applied to the LC layer ( 80 ). The amplitude of the applied electric voltages enables the fine tuning of the phase difference between the TM and TE components of the radiation polarization that is incident on the DS ( 42 ). The optical signal from the DS ( 42 ) passes through a polarizer ( 31 ) and arrives to the radiation detector ( 30 ). The analysis of the optical signal in the radiation detector ( 30 ) enables the quantitative determination of the analyte concentration in the close proximity of the DS ( 42 ).
In this case it is considered favourable that the radiation incident on the DS ( 42 ) contains both non-zero polarization components (TM and TE). The TE component does not change in terms of radiation intensity or phase, independently of the incidence angle (besides the classic changes expressed by the Fresnel relations and resulting from the refractive index and extinction coefficients, see reference 7) and depends only on the incident angles and on the refractive indexes of the substrate and the fluid. On the contrary, the TM polarization component changes sharply at a specific incidence angle due to the SPR effect. For example, the phase of the TM polarization component of the radiation shows an abrupt transition, typically over 180° in a range of incidence angles smaller than 10°.
FIG. 5B is a schematic illustration of the evolution of the radiation de-phasing as a function of the incident angle on the DS ( 42 ) for the detection surface of the device described in FIG. 5A . The phase φ_TE of the TE polarization component from the DS ( 42 ) does not show significant changes. The phase φ_TM of the TM polarization component changes sharply close to a specific incidence angle in which the SPR effect occurs. Initially the total phase difference between the TE and TM polarization components is typically high. By using an LC layer ( 80 ), that induces an additional phase difference φ_LC as a function of the applied voltage, it is then possible to properly adjust the phase difference between the two TE and TM polarization components of the radiation incident ( 101 ) on the DS ( 42 ), in order to have a phase difference of zero at the incidence angle at which the SPR effect occurs.
The detection polarizer ( 31 ) is placed in a perpendicular direction to the polarization direction of the incident radiation ( 102 ) and between the DS ( 42 ) and the radiation detector ( 30 ). In this way, when the de-phasing between the two polarization components is zero, one observes a total extinction of light after the detection polarizer and, on the other hand, one observes a maximum of radiation intensity after the detector polarizer ( 31 ) for a de-phasing of 90° (quarter-wave). This fact comes from the effect induced by the linear polarizer ( 31 ), since the intensity of radiation passing through the polarizer follows the relation (5):
I=I 0 cos 2 α (5)
in which I 0 is the intensity of the radiation incident on the polarizer and α is the angle between the linear polarization of the incident radiation ( 102 ) and the major direction of the polarizer.
Due to the sharp change on the relative phase of the TM component, one may observe two extinctions of light for two incidence angles corresponding to null or 180° de-phasing. Between these two radiation extinctions there is a local maximum of radiation intensity that corresponds to a de-phasing of 90°, according to FIG. 5C .
FIG. 5C is a schematic illustration of the SPR signal detected by the radiation detector for a conventional SPR detection device (dashed line) and for the device described in FIG. 5A (solid line), in which the detection polarizer ( 31 ) is placed approximately parallel to the SPR angle. Due to the sharp change of the TM component relative phase of the radiation coming from the DS ( 42 ), after passing through the detection polarizer ( 31 ) the signal presents a sharp intensity transition. One observes two minima of radiation intensity spaced by an angular distance W, with a local maximum between them. The angles of minimum intensity correspond to linear polarizations perpendicular to the major direction of the detection polarizer ( 31 ). The distance W is found to be minimized when the de-phasing (Δφ=φ_TE+φ_LC−φ_TM) is null for the angle of incidence in which the SPR effect occurs.
By applying an electric voltage to the LC layer ( 80 ) in order to vary the phase difference between the TM and TE components of the radiation polarization, it is then possible to adjust the angular position of the two light extinctions. The angular distance W between these extinctions increases when moving apart from and decreases when moving closer to the incidence angle at which the SPR effect occurs. Thus, it is possible to control the applied voltage on the LC layer ( 80 ) in order to minimize this angular distance W and determine in this way the minimum angular distance that corresponds to the angle at which the SPR effect occurs.
It is then possible, using this invention, to detect simultaneously the phase difference change of the radiation incident and also the angle in which the SPR occurs. The proper control of the total de-phasing induced by the LC layer ( 80 ) is feasible since the average orientation of the LC molecules ( 83 ) depends on the applied voltage. By combining these two effects (the de-phasing induced by the LC layer and the effect induced by the detection polarizer) it is then possible to obtain a SPR signal with much better contrast when compared with conventional SPR sensors.
The result of the this second embodiment would only be achieved in a conventional SPR sensor using a fixed quarter-wave or another element that would introduce a fixed de-phasing between TM and TE polarization components of the radiation incident on the DS ( 42 ), but nevertheless unable to dynamically adjust the de-phasing between both polarization components.
This example may be extended for SPR sensors ( 10 ) with different configurations, namely in the prismatic configuration and in the diffraction coupling configuration. It is also possible to obtain the same result when using other means for controlling the LC layer ( 80 ) as long as it is possible to properly adjust the average orientation of the LC molecules ( 83 ).
It is also possible to use an alternative configuration, in which the polarizer ( 31 ) is aligned in perpendicularly to the linear polarization direction for the incidence angle at which the SPR effect occurs. In this case one observes a similar signal to the one presented in FIG. 5C , but with two local maxima spaced by the angular distance W and having a minimum at the incidence angle at which the SPR effect occurs.
One other alternative configuration consists in using a LC layer ( 80 ) with a gradient of de-phasing φ_LC in a perpendicular direction to the direction of variation of the incident angles. In this case, the optical signal acquired by the radiation detector ( 30 ) is two-dimensional, with each line exhibiting the same behaviour described in FIG. 5C .
FIG. 5D is a schematic illustration of the evolution of the angle for the minimum of intensity of the SPR optical signal as a function of the radiation de-phasing for the detection device described in FIG. 5A , and in which the LC layer ( 80 ) induces a de-phasing in the perpendicular direction to the variation of the incident angles. In this case, the detection is performed using a two-dimensional radiation detector ( 30 ) of matrix type, in which is observed in each line a similar behaviour as described in FIG. 5C . The gradual change of the de-phasing enables the determination in real time of the line corresponding to the minimal distance W between the two local minima of the radiation intensity.
The man of the art may find several advantages when adopting this method, since the proper adjustment of the voltages applied to the LC layer ( 80 ) may be applied between signal acquisitions, contrarily to the other configurations previously presented.
All the previous configurations have considered an LC layer ( 80 ) placed in between the radiation emitter ( 20 ) and the DS ( 42 ). This is usually considered preferable due to its simplicity, since it enables the use of a collimated radiation beam and then placing the focusing elements after the LC layer ( 80 ).
FIG. 6 is a schematic illustration of the optical sub-system of radiation emission for an SPR detection device according to the present invention, in which a collimating lens ( 22 ) is used after the radiation emitter ( 20 ), and a emitter polarizer ( 23 ) placed between the lens and the LC layer ( 80 ) in the collimated radiation path. The emitter polarizer ( 23 ) is used in order to optimize the linear polarization of the incident radiation beam. After passing through the LC layer ( 80 ), the radiation is focused on the DS ( 42 ) by means of a focusing lens ( 24 ).
The configuration described in FIG. 6 is one of the possible configurations for the emitter sub-system, but other possible combinations might be used in order to obtain the same results previously described. For example, the emitter polarizer ( 23 ) might be eliminated when using a laser as the emission element ( 21 ), since laser typically emit polarized light. The collimating lens ( 22 ) may also be eliminated if the data processing takes into account the effect of the variable incident angle on the polarizer ( 23 ) and on the LC layer ( 80 ). The elimination of this collimating lens may introduce additional noise, although the man of the art is capable of properly taking into account this last effect on the signal processing algorithms.
It is also possible to consider an alternative configuration in which the LC layer ( 80 ) is placed in the optical path between the DS ( 42 ) and the radiation detector ( 30 ). In this latter case, there will be again the effect of the variable incident angle on LC layer ( 80 ) and on the detection polarizer ( 31 ) so this effect must be properly considered.
THIRD EXAMPLE
Conventional SPR detection devices typically use a radiation beam incident on the DS ( 42 ) in a fixed range of incident angles. This fact may also be a limiting factor in terms of sensitivity and detection range of the SPR detection device. It would then be interesting to use an SPR detection device having the possibility of controlling, in an easy way, the sensitivity limit and/or the detection range by acting on the range of incident angles of the radiation incident on the DS ( 42 ).
The third embodiment of the present invention consists of using two LC layers ( 85 ) and ( 86 ), controlled by an LC controller ( 84 ) and placed in between the radiation emitter ( 20 ) and the DS ( 42 ) in order to properly adjust the incidence angles of the radiation beam incident on the DS ( 42 ). A LC layer may behave as a lens due to the effect of local refractive index variation, namely as a function of an external applied voltage (see reference 8).
FIG. 7A is a schematic illustration of the resulting refractive index of the LC layer ( 80 ) described in FIG. 4B as a function of the applied voltage. The average refractive index of the LC layer ( 80 ) changes between the ordinary refractive index n o for low applied voltages (V<V_TH) and the extraordinary refractive index n e for sufficiently high applied voltages.
FIG. 7B is a schematic illustration of an LC layer behaving like an optical lens. In the rest condition (V<V_TH), the average orientation of the LC molecules ( 83 ) is uniform and parallel to the top and bottom LC substrates. For sufficiently high electric voltages, the LC molecules tend to be aligned along the electric field and thus present a spatial pattern. It is possible to build an LC Layer ( 80 ) that, for a fixed applied voltage, at its center presents a higher alignment of its molecules with respect to the applied electric field when compared to more external regions of the LC layer ( 80 ). The gradual change of the average orientation of the LC molecules ( 83 ) results in a spatial pattern of the effective refractive index of the LC layer ( 80 ) and so this latter behaving like an optical lens.
FIG. 7C is a schematic illustration of the equivalent focal distance of an LC layer ( 80 ) illustrated in FIG. 7B , as a function of the applied voltage. The equivalent focal distance of the LC layer ( 80 ) decreases when increasing the applied voltage. Within certain limits, the equivalent focal distance shows a linear dependency with the applied electric voltage.
There are several possible configurations that exploit this effect and enable the use of LC layers as optical lenses (see references 8 and 9 ). Given the SPR sensor ( 10 ) characteristics, it is considered favourable to have a constant and fixed focal length for the radiation incident on the DS ( 42 ). The resulting focal length of the association of two thin lenses is given by the relation ( 6 ):
f = f 2 ( d - f 1 ) d - ( f 1 + f 2 ) ( 6 )
in which d is the distance between the two lenses, f 1 and f 2 are the focal lengths of the lens 1 and lens 2 , respectively (see reference 7). The total range of incident angles is defined by Δα.
FIG. 7D is a schematic illustration of the optical sub-system of radiation emission for an SPR detection device according to the present invention, characterized in that two LC layers ( 85 ) and ( 86 ) are used, in order to have it working like a focusing lens of variable amplification with constant focal length. The radiation emitter ( 20 ) irradiates a collimated radiation beam onto a first LC layer ( 85 ) characterized by an equivalent focal length f 1 . A second LC layer ( 86 ), placed at a distance d from the first LC layer ( 85 ) and is characterized by a focal length f 2 . The group of these two LC layers is built and placed in such a way that it presents a constant focal length f and a controllable range of incident angles Δθ, simply by adjusting the electric voltages applied on the LC layers ( 85 ) and ( 86 ).
The group of LC layers ( 85 ) and ( 86 ) shows a constant equivalent focal length f and obeys the relation ( 6 ). The total range of incident angles Δθ is controllable through the applied electric voltages on the LC layers ( 85 ) and ( 86 ) and follows the relation (7):
Δ
θ
≈
arctan
(
h
1
2
d
2
-
f
1
(
d
+
f
2
)
f
2
(
d
-
f
1
)
)
(
7
)
This relation (7) is only valid if the LC layers ( 85 ) and ( 86 ) were much thinner than the distance d. This is the typical case, since common LC layers have a thickness between 1 μm and 100 μm and d is typically between 1 mm and 10 mm. The exact relation for the range of incident angles Δθ and may also be determined when the distance d is of the same order of the LC layer thickness, but in this latter case it becomes difficult to maintain the condition of constant focal length.
The control on the equivalent focal lens of an LC layer may be obtained by applying an external electric voltage, with a typical signal frequency between 1 KHz and 100 KHz, and voltage amplitudes between 0 V and 50 V. The effective refractive index of the LC layer may change with the applied voltage, depending on several parameters, namely: the structure of the LC layer, its thickness, the relation between the elastic, optical and dielectric constants of the LC molecules, the anchoring strength between the LC molecules and the LC substrates, among others. In a simplified approach, and within certain limits, it is possible to observe a linear dependency of the equivalent focal length of an LC layer when varying the applied voltage.
Let us consider, for example, two LC layer ( 85 ) and ( 86 ), built in such a way that each layer may vary linearly its equivalent focal length between 1 mm and 10 mm, depending on the applied voltage. For example, having 10 V of applied voltages induces an equivalent focal length of 10 mm and 20 V yields 1 mm of focal length). The two LC layers are placed at a distance of 10 mm, and the collimated radiation beam has 5 mm of diameter when arriving to the first LC layer ( 85 ). In this example, the radiation incident on the DS ( 42 ) will have a total focal length of 20 mm. Now, maintaining this total focal length at 20 mm and according to equations (6) and (7), it is possible to vary the total range of incident angles Δθ from 48° (with V 1 =20.000 V and V 2 =14.215 V) to 1.8° (with V 1 =12.222 V and V 2 =19.091 V).
The practical use of this example of the present invention may require the man of the art a special care in the measure and control of optical aberrations and distortions induces by the group of LC layers behaving like a variable amplification lens with constant focal length. This determination and control may the obtained with precision (see reference 10) in order to minimize the noise associated to the detection based on the SPR effect.
This third embodiment of the present invention may be extended to other configurations of detection devices based on the SPR effect, namely in the cases of the prismatic configuration or the grating coupling configuration. It may also be considered with advantage other means for controlling the average orientation of the LC molecules ( 83 ) of the LC layers ( 85 ) and ( 86 ), wherein the applied voltage amplitude is kept constant and only the signal frequency is varied. In this case, the man of the art may choose a suitable frequency range wherein the LC molecules ( 83 ) response is strongly dependent on the signal frequency.
Another alternative configuration of this embodiment consists in using two LC layers ( 85 ) and ( 86 ) placed in the optical path between the DS ( 42 ) and the radiation detector ( 30 ). This last configuration may be considered with advantage since all the elements with high optical quality are placed in the proximity of the radiation emitter ( 20 ), and so it may optimize the SPR effect on the DS ( 42 ). This latter case may imply the use of an additional detection lens ( 32 ), placed in between the DS ( 42 ) and the LC layers ( 85 ) and ( 86 ), in order to have a collimated beam before the first LC layer ( 85 ).
FIG. 8 is a schematic illustration of a detection device according to the present invention, in which a group of two LC layers is placed in between the detection surface ( 42 ) and the radiation detector ( 30 ) in order to control the radiation signal amplification. The incident radiation ( 101 ) is reflected at the DS ( 42 ) and the reflected radiation ( 102 ) is transmitted through detection lens ( 32 ) and then passes through the LC layers ( 85 ) and ( 86 ) and arrives to the radiation detector ( 30 ). The LC layers ( 85 ) and ( 86 ) are controlled by the LC controlled ( 84 ). By properly adjusting the applied voltages on the LC layers ( 85 ) and ( 86 ) it is possible to control the diverging angle of the reflected radiation ( 102 ). This control enables the adjustment of the detection range and sensitivity limit of the SPR sensor ( 10 ).
In this case the group of LC layers ( 85 ) and ( 86 ) enable the control of optical signal amplification around the angle in which the SPR effect occurs. For example, it is possible to defined a minimum acceptable contrast of the SPR optical signal and then gradually adjust the amplification of the group of LC layers ( 85 ) and ( 86 ) in order to maximize the resolution of the detection device, keeping a signal to noise rate rather constant.
These examples demonstrate some different possible embodiments of the present invention in order to build and use an SPR sensor ( 10 ) using LC layers that enables the detection of chemical and/or biological events, with a better performance when compared to conventional SPR detection devices.
Summary of the abbreviations
SPR sensor 10
Radiation emitter 20
Emission element 21
Collimating Lens 22
Emitter Polarizer 23
Focusing Lens 24
Radiation Detector 30
Detection Polarizer 31
Detection Lens 32
Fluidic Channels 40
Detection Zone (DZ) 41
Detection Surface (DS) 42
Channels 43
Substrate 44
Liquid Crystal (LC) Layer 80
Bottom LC substrate 81
Top LC substrate 82
LC Molecules 83
LC Controller 84
First LC Lens Layer 85
Second LC Lens Layer 86
Prism 90
Incident Radiation 101
Outgoing Radiation 102 | A detection device based on the surface plasmon resonance effect, including a radiation emitter and a radiation detector, a fluidic substrate, a liquid crystal layer and respective control mechanism. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a class of proteins, a process of production thereof, and a method for treatment of neurological and viral diseases and especially to the treatment of heretofore intractable diseases such as retro-viral infections, including specifically HIV infections.
[0003] 2. Description of Prior Art
[0004] Sanders, et al. had commenced investigating the application of modified venoms to the treatment of ALS in 1953 having employed poliomyelitis infection in monkeys as a model. Others antiviral studies had reported inhibition of pseudorabies (a herpesvirus) and Semliki Forest virus (alpha-virus). See Sanders' U.S. Pat. Nos. 3,888,977, 4,126,676, and 4,162,303. Sanders justified the pursuit of this line of research through reference to the studies of Lamb and Hunter (1904) though it is believed that the original idea was postulated by Haast. See Haast U.S. Pat. Nos. 4,341,762 and 4,741,902. See also MacDonald, et al., U.S. Pat. No. 5,723,477. The studies of Lamb and Hunter (Lancet 1:20, 1904) showed by histopathologic experiments with primates killed by neurotoxic Indian cobra venom that essentially all of the motor nerve cells in the central nervous system were involved by this venom. A basis of Sanders' invention was the discovery that such neurotropic snake venom, in an essentially non-toxic state, also could reach that same broad spectrum of motor nerve cells and block or interfere with invading pathogenic bacteria, viruses or proteins with potentially deleterious functions. Thus, the snake venom used in producing the composition was a neurotoxic venom, i.e., causing death through neuromuscular blockade. As the dosages of venom required to block the nerve cell receptors would have been far more than sufficient to quickly kill the patient, it was imperative that the venom was detoxified. The detoxified but undenatured venom was referred to as being neurotropic. The venom was preferably detoxified in the mildest and most gentle manner. While various detoxification procedures were known then to the art, such as treatment with formaldehyde, fluorescein dyes, ultraviolet light, ozone, heat, it was preferred that gentle oxygenation at relatively low temperatures be practiced, although the particular detoxification procedure was not defined as critical. Sanders employed a modified Boquet detoxification procedure using hydrogen peroxide, outlined below. The acceptability of any particular detoxification procedure was tested by the classical Semliki Forest virus test, as taught by Sanders, U.S. Pat. No. 4,162,303.
[0005] U.S. Pat. No. 3,888,977, issued on Jun. 10, 1975 to Murray J. Sanders (the entire disclosure of which is incorporated herein by reference and relied upon for details of disclosure) teaches that animals, including humans, may be treated for progressive degenerative neurological diseases, such as amyotropic lateral sclerosis, by administration of a modified snake venom neurotoxin derived from the venom of either the Bungarus genus (including the Crotalus genus) or from a combination of the Bungarus genus and the Naja genus, i.e., in either case the therapeutic composition must contain at least in part modified neurotoxin derived from the Bungarus genus. Thus, it is taught that while the Bungarus venom can be effectively used alone, the Naja venom must be used in combination with the Bungarus venom. Unfortunately, however, Bungarus venom is not as readily available as Naja venom; the supply thereof is more uncertain; and it is far more expensive than the Naja venom. Sanders U.S. Pat. No. 4,126,676 (1978) provided a method of treatment of animals suffering from progressive degenerative neurological diseases wherein the therapeutic modified neurotoxin was derived from the Naja genus alone. Miller, et al. (1977) reported that the modified venoms antiviral activity against Semliki Forest virus was associated with several chromatographic fractions comprising the neurotoxic components. The most abundant component with antiviral activity was shown to be alpha-cobratoxin. Yourist, et al. (1983) reported that modified alpha-cobratoxin could inhibit the activity of herpesvirus. It seemed therefore, that these modified venoms and constituents had significant inhibitory activity against unrelated viruses. This non-specific activity has prompted the examination of these modified venom products against a number of viral types.
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SUMMARY OF THE INVENTION
[0007] The present invention provides a composition and method for treating and preventing retroviral infections of mammalian cells. One aspect of the invention relates to the identification of modified neurotoxins capable of preventing HIV infection and replication in that cell. In another aspect the invention relates to an retroviral composition derived from modified venom which can be administered in-vivo for the treatment of HIV infection. In another aspect, the invention relates to the synergistic effects of modified venom constituents in preventing HIV infection and replication. In another aspect, the retrovirus is selected from the group consisting of Lentiviruses (HIV-1, HIV-2, SIV, EIAV, BIV, and FIV).
[0008] Proteins such as those from venoms, as described herein, have long been recognized for their ability to bind to specific receptors on the surface of mammalian cells. These neurospecific proteins bind to such common receptors as the acetylcholine receptor for example. However, the protein motif employed by these neurotoxins to affect binding appears to be a common motif employed by other, apparently unrelated, proteins including those present in viral coat proteins. Such viral proteins include rabies virus coat protein and gp120 from HIV. Prior studies had indicated that proteins with these motifs could interfere with the activity of the other. Sanders provided a method which permits the safe administration of venom proteins allowing the application of these laboratory observations to practical use. Therefore included in the invention is a method of treating lentivirus infection in mammals and humans comprising administering to the host of either the modified venom or the modified neurotoxin.
[0009] In yet another aspect of the invention is the indication that modified neurotoxins can bind to a HIV receptor protein and/or a cellular cofactor unrelated to their original target receptors. The specific entity to which MCTX binds is presently unknown, though it appears to have an impact upon viral infection late in infection, possibly during maturation of infectious particles.
[0010] In another aspect of the invention, the modified venom's higher antiviral activity suggests the existence of synergism between venom components due to the presence of other neurotoxic components in addition of alpha neurotoxin known as cobratoxin. Therefore, as a group consisting of modified alpha-neurotoxins with homologous domains and acetylcholine receptor binding activity can inhibit lentivirus infection and could be selected from but not limited to alpha-cobratoxin, alpha-bungarotoxin, alpha-cobrotoxin and alpha-conotoxin.
DETAILED DESCRIPTION OF THE INVENTION
[0011] Although the survival of individuals currently infected by the HIV virus is dramatically longer than it was 20 years ago, such survival is at the cost of a drug regime which is highly expensive, complicated, relegated to a fixed time and sequence schedule, has adverse physiological side effects and is, ultimately, too little too late. While the logical method to halt the spread of the disease is sexual abstinence, such method embodies so many facets of world society, that, realistically, the disease will remain uncontrollable until such a time as it can be controlled by methods which are inexpensive, have few side effects, and can be administered easily.
[0012] Prophylaxis, utilized before or after potential exposure, fulfills these requirements. Potential prevention/treatment could take many forms; three are: 1. The development of a vaccine that prevents infection; 2. Prevention of an initial infection or control of the spread of an initial infection that has not progressed to AIDS by a means other than a vaccine, or, 3. A resolution of the syndrome known as AIDS by the use of anti-retroviral agents. While vaccine production is ultimately the most efficacious of the three methods, due to the mutational idiosyncrasies of the virus, such development is not a likely or a probable immediate occurrence. Vaccine development attempts to date have failed to translate into man from animal test-models (Peters; 2000).
[0013] Medical research resources are currently being applied to the management, rather than the cure of a HIV infection. While the use of anti-retrovirals agents have improved the quality and length of life, they have disadvantages which include toxicity, development of drug resistance, persistence of latently infected cells resulting in viral rebound after prolonged treatment and, finally, high expense. The prevention and/or control of an infection prior to loss of immune capabilities associated with progression to AIDS is currently the most expedient and cost effective method. Currently, there are several approved drugs types that apply themselves to the control of an ongoing HIV infection. These drug types are, nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors and protease inhibitors. These are currently encompassed by highly aggressive anti-retroviral therapy (HAART). All these drug types are susceptible to loss of effectiveness due to genetic mutation of the HIV-1. Thus, the blockade of HIV infection or the control of the spread of HIV infection through the use of fusion or entry inhibitors appears to be the most logical method barring the availability of a vaccine. Such blocking substance, or substances, could be applied topically, as a cream or douche, and provide protection during coitus. The use of this mode of prevention has been suggested by others (Turpin, 2002) and is being implemented (Van Damme, et al., 2000). The utilization of a binding/entry inhibitor as a prophylactic that would block infection and maintain a period of protection in the genital tract could provide an effective measure which would reduce HIV-1 transmission (D'Sousa, et al., 2000). Topical administration would not be amenable to prevention of disease by blood transfer by more direct routes (such as needles). However, as an injectable, or by buccal administration, it could be applicable parenterally in the treatment of an HIV infection during early stages of exposure, or later, by providing control of HIV dissemination within the host.
[0014] Alternatively, drug activities which alter the virus and reduce its infectivity or alter its functional form upon release would supply a mechanism for infection control at the “other side” of the infection sequence.
[0015] HIV-1 is a lentivirus (lenti=slow {Latin}) of the family Retroviridae. The virus is enveloped, 80-130 nm in diameter and has an icosahedral capsid. As with other lentiviruses, HIV can infect terminally differentiated, non-dividing cells such as macrophages resident in tissue or brain (microglia) as well as cells of the T cell lineage, specifically CD4+ cells, known as T helper (TH) cells. Lentiviruses have, through mutation, the capability to infect immune cells (macrophages; TH-cells), the ability to avoid immune system eradication and, thus, tend to persist for the life of their host. The typical HIV infection progresses through three stages: initial, or acute, associated with high levels of viral replication and dissemination, a latent stage attributed to partial immune system control, which is followed by the third stage which encompasses the return of high levels of viral replication and progression to clinical disease states due to decreased immunocompetence, termed acquired immunodeficiency syndrome (AIDS). HIV is suggested to be derived from the simian immunodeficiency virus (SIV) (Courgnaud, et al., 2001) and first entered the human population between 1915 and 1941 (Korber, et al., 2000). Two HIVs are associated with human AIDS: HIV-1 and HIV-2. HIV-1 is distributed worldwide and is responsible for the current AIDS pandemic while HIV-2 is currently restricted to West Africa. Both are spread by the same routes, though HIV-2 may be less pathogenic.
[0016] Treatment of HIV infection currently encompasses two basic modalities: drug action at host intracellular targets (post entry) and drug interaction at viral extracellular targets (pre-entry). The latter are termed as binding/entry inhibitors. Extracellular targets are those associated with viral attachment, fusion and entry into the host cell. Intracellular targets are those associated with viral nucleic acid synthesis and processing and are termed as anti-retroviral drugs. There are currently 16 licensed antiretroviral drugs employed to combat HIV-1 infection (D'Souza, et al. 2000, aidsmeds.com, 2002a). Currently, there is a drug, T-20 (Trimeris), which is licensed as a binding/entry inhibitor. Within the context of this proposal, extracellular targets are of immediate importance, consequently, discussions of viral inhibition post-cell entry will be omitted.
[0017] Infection by HIV occurs following the introduction of the virus to the blood of the potential host. Virus-host cell interaction is mediated through the viral envelope glycoproteins gp120 and gp41 (gp160), which are assembled as trimers on the surface of the viral envelope, and their interactions with host cell surface receptors CD4, and CXCR4 or CCR5. U.S. Pat. No. 5,994,515 (Hoxie) describes the manner in which the human immunodeficiency viruses HIV-1 and HIV-2 and the closely related simian immunodeficiency viruses (SIV), all use the CD4 molecule as a receptor during infection though viruses like HIV and FIV can infect CD4 negative cells. The latter two host cell surface receptors are chemokine receptors and act as co-receptors along with CD4. Chemokines are a large family of low molecular weight, inducible, secreted, proinflammatory cytokines which are produced by various cell types. See, for instance, Au-Yuong, et al., U.S. Pat. No. 5,955,303. Chemokines have been divided into several subfamilies on the basis of the positions of their conserved cysteines. The CC family includes monocyte chemoattractant protein-1 (MCP-1), RANTES (regulated on activation, normal T cell-expressed and secreted), macrophage inflammatory proteins (MIP-1.alpha., MIP-1.beta.), and eotaxin. (Proost, P. (1996) Int. J. Clin. Lab. Res. 26: 211-223; Raport, C. J. (1996) J. Biol. Chem. 271: 17161-17166). The CXC family includes interleukin-8 (IL-8), growth regulatory gene, neutrophil-activating peptide-2, and platelet factor 4 (PF-4). Although IL-8 and PF-4 are both polymorphonuclear chemo-attractants, angiogenesis is stimulated by IL-8 and inhibited by PF-4. However, the macrophage tropic (CCR5) strain BaL, is not capable of infecting cells which co-express both CXCR4 and CD4. These results suggest that CXCR4 can serve as a co-factor for T-tropic, but not M-tropic, HIV-1 strains (Feng, et al., 1996, supra). Moreover, the finding that there is a change from M to T-tropic viruses over time in infected individuals correlates with disease progression suggests that the ability of the viral envelope to interact with CXCR4 represents an important feature in the pathogenesis of immunodeficiency and the development of full blown AIDS.
[0018] There are five variable regions and five conserved regions that compose gp120 (Starcich, et al., 1986; Wyatt, et al., 1995). Two variable loop regions, V1/V2 and V3, prior to initial viral interaction with the cell surface, are closely associated and block accessibility to a region associated with chemokine receptor binding. Binding of CD4, which occurs above these two variable regions, is dependent upon discontinuous elements in conserved regions 3 and 4 (C3 and C4)(Moore, et al., 1994). Amino acid changes in the V2 and V3 loop regions can alter both the membrane fusion process and HIV-1 tropism (Wyatt, et al., 1995).
[0019] Infection of susceptible cells occurs via three conformational stages involving HIV-1 gp120 (D'Sousa et al., 2000). In short, the interaction between HIV-1 and the host cell proceeds as follows: A segment of gp120 binds to CD4 on the host cell surface resulting in an initial conformational change of the V1/V2 and V3 regions of gp120. This change allows access to a portion of gp120, previously covered by the two variable regions, which binds with a co-receptor resident on the host cell. This gp120 conformational change involves movement of the V1/V2 loops away from the V3 loop (Thali, et al., 1993; Wyatt, et al., 1995, Sullivan, et al., 1998). Under normal circumstances, HIV-1 gp120 requires the presence of both the CD4 and a co-receptor to cause additional conformational changes resulting in exposure of gp41. The viral protein, gp41, is responsible for fusion and entry. The CD4 co-receptor is either CXCR4 or CCR5 and is determined by the tropism of the virus (Feng, et al., 1996; Doranz, et al., 1996; Deng, et al., 1996; Choe, et al., 1996; Wu, et al., 1996). The extracellular portion of gp41 contains two helical domains: HR1 and HR2 (or NHR and CHR; Jiang, et al., 2002). The tip of gp41 inserts into the host cell membrane and anchors the virus to the cell. The two helical domains of gp41, previously separated by a segment of gp120, bind together to form a 6-helix bundle that is a fusogenic structure (Jiang, 2002). The virus and cell surface are pulled together by this structure, allowing fusion of the virus envelope and host cellular membrane and insertion of viral genetic material. The co-receptor CCR5, whose natural ligands are the a chemokines RANTES, MIP-1-a, MIP-1-t and MDC, is employed by primary isolates of HIV-1 which are generally M (macrophage) tropic, and is found on T cells and macrophages. CXCR4, whose natural ligand is SDF-1a, is employed by late stage HIV-1 isolates and is employed by T (T cell)-tropic HIV-1. There is an in vivo switch in tropism during HIV infection (Wyatt and Sodroski, 1998).
[0020] Due to the complexity of the binding and penetration of HIV-1, the virus is, at least theoretically, vulnerable to either single or, more especially, multiple entry inhibitors. Therefore, there are several cellular sites and viral sites with which inhibitors could interact to halt the process: CD4, CXCR4, CCR5, gp120 and gp41. The substances currently under consideration generally have high cost in addition to limited production as well as low bio-availability and poor pharmacologic and toxicology profiles. Nineteen potential binding/entry inhibitors were listed in 2000 (D'Sousa, et al., 2000); work is still progressing and a glance at the current literature indicates new additions in the list. Gp41 inhibitors T-20 and T-1249 (Trimeris/Hoffman LaRoche) as well as PRO-542 (Progenics), PRO-2000 (Procept) and Cyanovirin (CV-N) all of which target virus/CD4 interaction and AMD-3100 (AnorMed), which interferes with HIV/CXCR4 interactions, are still viable candidates. These compounds are representative of, and provide an overview of, current thought in the area of inhibiting viral binding/entry (De Clercq, 2002).
[0021] The drug candidates listed above suggest that combinatorial efforts to prevent binding and entry is likely to become the norm, as opposed to the use of single drugs, as indicated by the synergistic combination of drugs with T-20. Additionally, the concept of disease prevention by the use of binding/entry inhibitors is established in the research and clinical communities. The use of PRO-2000 in a vaginal gel, coupled with the early results achieved, suggest that this is a potentially viable approach, especially given that this is associated with the most frequent mode of transmission (Greenhead, 2000). This topical approach is strengthened by the determination that HIV must transit the epithelial lining of the vagina wall to access infection susceptible cells, that epithelial cells are not subject to infection and they do not aid transport of the virus. In fact, the epithelial cells may act as a barrier to infection. The presence of PRO2000 was found to result in 97% reduction in HIV infection in an in-vitro cervical explant test system (Greenhead, 2000).
[0000] Molecular Mimicry; Alpha-neurotoxin/HIV gp120 Sequence Homology
[0022] Death by cobra envenomation is attributed to the interaction of basic polypeptides (cobra alpha-neurotoxins) that act post-synaptically and result in blockade of nerve transmission due to their affinity for the nicotinic acetylcholine receptor (nAchR). nAchRs are ligand-gated ion channels activated by the binding of acetylcholine (Ach). On muscle, the nAchR molecule is a pentamer composed of two alpha subunits, one beta, one gamma and one delta subunit. Ach binds to the alpha subunit, each nAchR complex having two acetylcholine binding sites (Dowding et al., 1987). Cobratoxin and other snake alpha-neurotoxins are curaremimetic since they mimic the actions of curare in that they are potent competitive inhibitors of Ach binding to the nAchR and blocking Ach activity. The action of cobratoxin differs from that of curare and strychnine in that the effects of these two substances in vitro is reversed by washing, while the action of cobratoxin is irreversible. A large number of curaremimetic toxins have been isolated from the venoms of elapid and hydrophid snakes and similar curaremimetic toxins have been isolated from the venom of sea snails of the Conus genera. Overall, the snake proteins have a structural homology, being small proteins with a clover leaf-like shape consisting of three adjacent loops that emerge from a small globular core (LeGoas et al., 1992). The neurotoxin of the cobra of interest, Naja naja kaouthia , is a long chain neurotoxin that is cross-linked with 5 disulfide bonds (LeGoas et al., 1992). Loop one is partly hydrophobic and partly exposed to water, this portion having the greater flexibility. The central, or toxic loop, loop 2, is the largest loop and is mainly composed of two strands from the beta-pleated sheet. This loop bears an amino acid sequence homologous with HIV-1 gp120 and rabies virus glycoprotein (RVG). Loop 3 is closed by a disulfide bond and is nearly perpendicular to the beta sheet plane (LeGoas, et al., 1992). All known potent alpha-neurotoxins contain a single invariant tryptophan residue in the same or similar position in the primary sequence (Chang, et al., 1990). This tryptophan residue occupies amino acid position 28 in alpha-bungarotoxin ( Bungarus multicinctus ) and position 25 in alpha-cobratoxin ( Naja naja kaouthia ).
[0023] The a-neurotoxins of Naja naja kaouthia (cobratoxin) and Bungarus multicinctus (bungarotoxin) have a sequence homology with HIV gp120 and rabies virus glycoprotein (RVG) as indicated below in Table I. This homology is located in a manner that it is accessible for the production and interaction with antibodies on both viruses. Like the homologous sequence on elapid toxins, the amino acid sequence present in rabies virus glycoprotein (RVG) and gp120 of HIV results in interaction with the nAchR. This interaction has been demonstrated by the binding of rabies virus (Lentz, et al., 1982, Lentz, et al.,1987) and HIV-1 gp120 (Bracci, et al., 1992). Both viral interactions were blocked by the use of -bungarotoxin.
[0024] The apparent domain of sequence homology on HIV gp120 is located at amino acid residues 159-169, which places it at the initiation of the loop of the gp120 variable region 2 (V2), and is associated with the V1/V2 loop region.
TABLE I SEQUENCE HOMOLOGY OF HIV-1, RVG and SNAKE NEUROTOXINS RVG (189-199) C D I F T N S R G K I HIV-gp120 (159-169) F N I S T S I R G K V Peptide B2 S F N I S T S I R G K V Q I -cobratoxin (30-40) C D A F C S I R G K R -bungarotoxin (30-40) C D A F C S S R G K From Neri et. al.; 1990; Bracci et. al.; 1992; Bracci et. al.; 1997, Meyers and Lu; 2002
[0025] The apparent domain of sequence homology on HIV gp120 is located at amino acid residues 159-169, which places it at the initiation of the loop of the gp120 variable region 2 (V2), and is associated with the V1/V2 loop region.
[0026] There are five variable regions and five conserved regions on gp120 (Starcich, et al., 1986; Wyatt, et al., 1995). Binding of CD4 is dependent upon discontinuous elements in conserved regions 3 and 4 (C3 and C4) while the V3 and V4 regions are the most exposed elements of the multimeric envelope glycoprotein complex (Moore, et al., 1994). Changes in the V2 and V3 loop regions can alter both the membrane fusion process and HIV-1 tropism (Wyatt, et al., 1995).
[0027] The sequence homology existing between gp120 and snake a-neurotoxins is not obviously associated with the host cell CD4 binding, in the context of a known receptor sequence on the CD4 molecule. Thus there does not appear to be an obvious association between the sequence and viral interaction with potential host cells, given the currently accepted binding/entry scenario. With respect to that scenario, as indicated previously, there are considerable viral conformational alterations associated with the CD4-gp120 interaction. Binding thermodynamics, as reported by Myszka, et al; (2000), are of unexpected magnitude and indicative of extensive structural rearrangements. One of these rearrangements is the movement of the V1/V2 loops which results in the exposure of the conserved discontinuous structures which are recognized by monoclonal antibodies (Thali, et al., 1993; Wyatt, et al., 1995; Sullivan, et al., 1998). Conformational alterations of the V1/V2 loop structures also result in exposure of the site for interaction with the CCR5 chemokine receptor (Kolchinsky, et al., 2001). It has been suggested, based upon an induced mutation of the a3 strand of the bridging sheet between V1/V2 and V3 (Zhu, et al., 2001), that there is a direct interaction between V1/V2 and V3. Since the V2 loop gp120 site is exposed on an aspect of the protein that interacts with the potential host cell (Wyatt and Sodroski, 1998), and the demonstrable presence of nAchR on CD4+ cells, there is a possibility that a natural reaction with HIV-1 with nAchR occurs. The ability of HIV-gp120 to bind to the nAchR as well as the proven capability of modified neurotoxin to bind to the same receptor permits the hypothesis that modified neurotoxins may act as an entry inhibitor particularly in the nervous system.
[0000] The Presence of nAchR on CD4+ Cells.
[0028] A better and more documented rational for modified neurotoxins, potential as HIV-1 entry inhibitors of lymphocytes is in the interaction of the homologous a-neurotoxins with nAchR present on CD4+ cell surfaces. Human “T” lymphocytes are a major source for acetylcholine (Ach) (Fujii and Kawashima, 2001; Sato, et al., 1999; Kawashima, et al., 1998; Fujii, et al., 1996). Additionally, there is a substantial body of work indicating the presence of both muscarinic AchRs (mAchRs) and nicotinic AchRs on the surface of human peripheral blood mononuclear cells (PBMC) (Fujii and Kawashima, 2001; Singh, et al., 2000; Kawashima and Fujii, 2000). Messenger RNA expression of subunits for both nAchR (a2-a7 and a2-a4) and mAchR (m1-m5) was determined for human PBMC indicating the presence of AchR on the cell surface (Sato, et al., 1999). Others (Battaglioli, et al, 1998) have determined the presence of the nAchR a3 promoter in T lymphocytes. Stimulation of T lymphocytes with the mitogen phytohemagglutinin (PHA) results in increased synthesis and release of Ach as well as an increase in mRNA encoding for nAchR and mAchR (Kawashima and Fujii, 2000; Fujii and Kawashima, 2001) and suggests an autocrine and/or paracrine function for Ach in the regulation of immune function (Fujii and Kawashima, 2001). Inhibition of Concanavalin-A (Con A) induced T cell proliferation is blocked by the nAchR antagonist mecamylamine (MEC) and by acute nicotine exposure (Singh et al., 2000). Acute nicotine exposure of ConA stimulated mouse splenocytes resulted in decreased production of IL-10 and also resulted in increased production of IFN-gamma (Hallquist, et al., 2000). The presence of human lymphocyte cell surface nAchRs has been determined by the binding of fluoresceine isothiocyanate (FITC)-conjugated a-BTX; affinity purification of a-BTX bound protein indicated that the nAchR bound were the same as those found in muscle (Toyabe et al., 1997). Additionally, a monoclonal antibody (MoAb), designated as W6, competes with Ach for binding with a-BTX for the Torpedo nAchR a1 subunit (McLane et al., 1992). MoAb W6 mediated immuno-staining indicated the presence of nAchR on the surface of human PBMC which was situated in the perinuclear/surface region and which resembled the binding of antibody specific for CD4+ (Hiemke et al., 1996). The presence of surface a3 and a4 nAchR subunits was determined on human PBMC (Hiemke, et al., 1996) and studies by Benhammou, et al. (2000) using nicotine binding and determination of mRNA expression in PBMC also indicated the presence of a4-a3 and a3-a4 nAchRs. Others have determined the binding of 3 H-nicotine to human PBMC indicating the presence of nAchR on the surface with a calculated density of ˜2000 sites/cell (Grabczewska, et al., 1990). Additionally the binding of 3 H-nicotine to human neutrophils, monocytes and lymphocytes (Davies, et al., 1982) has been observed. The formation of E-rosettes, a function of T cells from peripheral blood, and a method used for T cell enumeration, is decreased by 30%-40% in the presence of carbamylcholine chloride, a cholinergic antagonist, indicating the expression of nAchR on at least a subset of human T cells (Mizuno, et al., 1982).
[0029] Therefore the target receptor for venom alpha-neurotoxins are readily expressed in a variety of cells that can also be infected with HIV. However, studies with other viruses have shown that native alpha-cobratoxin does not have any antiviral activity against either herpes or Semliki Forest virus. Formalin or heat denatured venom or cobratoxin, respectively, also displayed no antiviral activity while the heat-denatured CTX (resulting in beta elimination at the disulphide bonds as measured by mass spectromtry) was still capable of binding to its native receptor. Also, inhibition of viral infection, as by the rabies virus, could be observed in cells devoid of NAChR (BHK-21). Therefore it seemed unlikely that the NAChR receptor was part of the antiviral mechanism. Thus, the type of chemical modification is important to the activity of the final product.
Production Techniques
[0030] Administration of a highly toxic substance such as cobratoxin for therapeutic purposes is fraught with obvious difficulties, even when highly diluted. As a diluted substance, its potential effectiveness is reduced, and due to its high affinity for the nAchR, continued use could result in accumulation of the toxin at neuromuscular junctions and the diaphragm with the potential for adverse events. Alpha cobratoxin, of the Thailand cobra, Naja naja kaouthia , is a homogeneous non-glycosylated polypeptide composed of 71 amino acids with a molecular weight of 7821d and a pI of 9.6. Detoxification of alpha-cobratoxin can be achieved by exposure to heat, formamide, hydrogen peroxide, perchloric acid, ozone or other oxidizing agents. The result of exposure of cobratoxin to oxidizing agents is modification of amino acid side chains as well as the lysis of one or more disulfide bonds. Tu (1973) has indicated that the curaremimetic alpha-neurotoxins of cobra and krait venoms loose their toxicity upon either oxidation or upon reduction and alkylation of the disulfide bonds. The procedures used for detoxification described here are based upon the work of Sanders, who preferred the use of hydrogen peroxide (Sanders, et al., 1975). Loss of toxicity by oxidized alpha-neurotoxins (MCTX), as cobratoxin, can be determined by the intraperitoneal (IP) injection of excess levels of the modified protein into mice. In general, injection of 1.5 mcg of natural cobratoxin will result in the death of a 25 g mouse within 25 minutes. After detoxification, IP injection of a 200 mcL volume of 10 mg MCT/mL is non-toxic. This represents at least a 1300 fold reduction of toxicity.
[0031] Alternatively, an enzyme linked immunosorbant assay (ELISA) can evaluate loss of toxicity, as well as potential potency in terms of continued ability to bind to the nAchR. Although detoxified cobratoxin has lost a considerable proportion of its affinity for the nAchR, sufficient affinity remains such that it can be detected by an ELISA. This enables a measurement of the depression in binding of the modified neurotoxin to nAchR, indicative of loss of toxicity, while simultaneously indicating a continued ability of the modified toxin to bind to the nAchR providing a measure of potency (Raymond; unpublished data). To test the effectiveness, or potency of detoxified venom, Sanders utilized a plaque assay with Semliki Forest virus (Miller, et al., 1977).
[0032] Sanders applied detoxified cobra venoms to the treatment of polio (Sanders, et al., 1953, 1954a, 1954b, 1958a, 1958b) in primates and amyotrophic lateral sclerosis (ALS) (Sanders and Fellows 1974, 1975, 1978) over a 14-year period under an FDA approved IND. Sanders based his work around the observations of Lamb and Hunter (1904) who demonstrated central nerve cell destruction following Naja naja venom exposure. Sanders postulated the notion of steric interference and/or molecular mimicry where detoxified neurotoxins would have the similar access to the CNS and be capable of blocking nerve cell receptors rendering them unavailable for involvement by deleterious neuro-invasive bacteria, viruses or proteins. Thus, the progression of degenerative neurological diseases could be halted or their progression slowed allowing the immune system time to resolve the disease state.
[0033] In a preferred embodiment, the method of the present invention is used to prepare inactivated forms of venoms or neurotoxins, and more preferably neurotoxins listed in the group below.
Snake Venoms Naja sp., Bungarus sp., Ophiophagus sp., Hemachatus sp., Boulengeria sp., Pseudohaje sp., Walterinnesia sp., Dendroaspis sp., Elaps sp., Acanthophis sp., Notechis sp., Oxyuranus sp., Pseudechis sp., Pseudonaja sp., Aipysurus sp., Astrotia sp., Enhydrina sp., Hydrophis sp., Lapemis sp., Laticauda sp., Pelamis sp., Other venom Conus sp. a-Neurotoxins -cobratoxin, -cobrotoxin, -bungarotoxin, erabutoxin, -conotoxins and muscarinic anticholinergic proteins, M1, M2 and M3.
[0034] Recombinant techniques may prove useful in the production of this antiviral peptides. The cloning of a variety of neurotoxins have proven successful though the majority of efforts have focused upon those toxins which are found only in low quantities in native venoms (Fiordalisi, et al., (1996) Toxicon 34, 2, 213-224, Krajewski, et al. (1999) “Recombinant m1-toxin” presented at the 29 th Annual Meeting of the Society for Neuroscience) and also with the desire to produce mutants to study structure/function relationships (Smith, et al., (1997) Biochemistry, 36, no. 25, 7690-7996. Cobratoxin has been cloned (Antil S., Servent D. and Menez A. J. Biol. Chem. (1999) Dec 3; 274(49): 34851-8)[.] Although cobratoxin is abundant and easily obtained from natural sources, in order to study the effect of mutations on its interactions with the acetylcholine receptor, specific recombinant production is desirable. Several bioengineered variants have been proposed by the author who was a contributor to the Smith, et al. (1997) paper which replace the residues required for disulphide bond formation with other residues so as to closely mimic the effects of chemical modifications. As these amino acid substitutions must be expressed in-vivo the availability of modifications are limited to the use of native residues (the standard 20 naturally occurring amino acids) and the host to be employed for expression. In the host the codon usage will be important in ensuring efficient and maximal expression of the novel protein. Theoretically any amino acid can be substituted for cysteine but as this is a more costly approach to generating cobratoxin variants relative to synthetic peptide techniques certain residues have been selected which best reproduce the protein characteristics resulting from chemical exposure. It is usual in this circumstance to make what are considered to be conservative substitutions. As a result, it has been chosen to initially limit the cysteine replacement to the following residues; methionine (M), glutamic acid (E), aspartic acid (D), glutamine (Q), asparagine (N), serine (S), glycine (G) and alanine (A). Methionine incorporation would could be considered to be the more conservative substitution by, replacing one sulphur-containing residue for another. Unlike cysteine, methionine cannot form disulphide bonds. Methionine also reacts readily with oxidizing agents to produce the sulfone derivative therefore the purified product can be exposed to chemical agents to confer upon the protein other desirable properties (i.e., low immunogenicity). Also the presence of methionine also allows for the cleavage of the protein into fragments employing cyanogen bromide. Cleavage of the native cobratoxin and modified protein is easily achieved with serine proteases (i.e., trypsin) but at sites containing positive residues. This permits also the evaluation and production of smaller peptide fragments for biological activity (Hinmann, et al., 1999). The conversion of cysteine to cysteic acid also argues for the substitution by other acidic residues such as E, D, Q, N and S. The substitution of E and D for cysteine is estimated to produce a protein with a pI similar to that of modified cobratoxin (pI=4.5). The substitution of cysteine with the residues glycine and alanine would represent standard “neutral” substitutions. The method for creating these genes has been described previously (Smith, et al., 1997). The codon usage of the DNA fragments is optimized for use in commercially used bacterial and yeast expression systems Escherichia coli and Pichia pastoris respectively.
[0035] Current technology has also allowed for the production neurotoxins through peptide synthesis. Many smaller neurotoxins (from conus snails, bee venom and scorpion venom) are routinely produced by synthetic peptide methodology (Hopkins, et al., (1995) J. Biol. Chem., 270, no. 38, 22361-22367, Ashcom and Stiles, (1997) Biochem. J. 328, 245-250, Granier, et al., (1978) Eur. J. Biochem., 82, 293-299 and Sabatier, et al., (1994) Int. J. Pept. Protein Res., 43, 486-495) and some are available from commercial organizations. The above references also describe the synthesis of such peptides incorporating mutant residues (Hopkins, et al. (1995) and Sabatier, et al (1994)). Current techniques in peptide chemistry allow for proteins in excess of 80 amino acids can be reliably produced using automated Fmoc solid phase synthesis (ABI 433A Peptide Synthesizer, Perkin Elmer—see www.perkin-elmer.com). Non-native amino acids (acetamidomethyl cysteine, carboxyamidomethyl cysteine, cysteic acid, kynurenine and methionine sulphone) can be acquired from Advanced Chemtech (Louisville, Ky.) or Quchem (Belfast, Ireland). Other oxidized or alkylated amino acid variants are available from these agents. The generation of a synthetic version of the neurotoxin can be achieved by substituting primarily the cysteine residues (from 1 pair to all 5 disulphide couples) with those residues described above to mimic the effects of the various chemical modifications. Furthermore the substitution of other native and non-native residues for cysteine can be investigated in an attempt to identify neurotoxin variants with improved biological activity. Also peptide fragments from within the cobratoxin sequence can be created (analogous to Hinmann et al., (1999), Immunoparmacol. Immunotoxicol., 21 (3), 483-506) and examined for receptor binding activity.
[0036] To inhibit infection of cells by HIV in vitro, cells are treated with the MCTX of the invention, or a derivative thereof, either prior to or concurrently with the addition of virus. Inhibition of infection of the cells by the MCTX of the invention is assessed by measuring the replication of virus in the cells, by identifying the presence of viral nucleic acids and/or proteins in the cells, for example, by performing PCR, Southern, Northern or Western blotting analyses, reverse transcriptase (RT) assays, or by immunofluorescence or other viral protein detection procedures. The amount of MCTX and virus to be added to the cells will be apparent to one skilled in the art from the teaching provided herein.
[0037] To inhibit infection of cells by HIV in vivo, the MCTX of the invention, or a derivative thereof, is administered to a human subject who is either at risk of acquiring HIV infection, or who is already infected with HIV. Prior to administration, the MCTX, or a derivative thereof, is suspended in a pharmaceutically acceptable formulation such as a saline solution or other physiologically acceptable solution which is suitable for the chosen route of administration and which will be readily apparent to those skilled in the art of MCTX preparation and administration.
[0038] Typically, the MCTX is administered in a range of 0.1 mcg to 2 mg of protein per dose. Approximately 1-10 doses are administered to the individual at intervals ranging from once per day to once every few years. The MCTX may be administered by any number of routes including, but not limited to, subcutaneous, intramuscular, oral, intravenous, intradermal, intranasal or intravaginal routes of administration. The MCTX of the invention may be administered to the patient in a sustained release formulation using a biodegradable biocompatible polymer, or by on-site delivery using micelles, gels and liposomes, or rectally (e.g., by suppository or enema). The appropriate pharmaceutically acceptable carrier will be evident to those skilled in the art and will depend in large part upon the route of administration.
EXAMPLES
Example 1
[0039] Venom Modification
[0040] Venom from the Thailand cobra ( Naja naja kaouthia ) was purchased from Biotoxins (Florida) or Kentucky Reptile Zoo (Kentucky). Employing the procedure described by Sanders (U.S. Pat. No. 3,888,977) and Miller, et al. (1977) the reactive molecule, hydrogen peroxide, the precursor protein is modified through the addition of oxygen molecules.
[0041] Other venoms detoxified in this manner include venoms from Naja naja atra, Bungarus multicintus , and Crotalus durissus terrificus.
Example 2
[0042] Neurotoxin Modification
[0043] Cobratoxin (CTX) has a molecular weight of 7821 and is composed of 71 amino acids. Alpha-cobratoxin from the Thailand cobra ( Naja naja kaouthia ) was purchased from Biotoxins, Kississimi, Florida. Employing the procedure described by Sanders (U.S. Pat. No. 3,888,977) and Miller, et al. (1977) the reactive molecule, hydrogen peroxide, the precursor protein is modified through the addition of oxygen molecules.
[0044] A modified neurotoxin (MCTX) solution has an acidic pH and a pI of approximately 4.5. Cobratoxin solutions are basic having pH of [10.4]. 8.5. In solution, the drug migrates through molecular sieving gels as monomers, dimers and tetramers. Cobratoxin migrates under these conditions as a monomer. Upon analysis on NuPAGE (Stratagene) SDS polyacrylamide gel electrophoresis (PAGE) the cobratoxin migrates as a 14 Kd and 8 Kd protein with a reference to comparable proteins under unreduced and reduced conditions respectively. MCTX migrates under reduced and unreduced conditions without change. A single protein band is not obtained showing a diffuse smear from the loading gel down to a molecular weight equivalent to 8 Kd. Additionally, the protein is resistant to staining with standard coomassie dyes. By ion exchange, cobratoxin and MCTX have generally opposite properties consistent with the proteins' charges. Specialized ion-exchange chromatographic resins and conditions can be employed to confirm the retention of positive charges which are considered critical for neuroactive properties.
[0045] As defined by mass spectrometry the molecular weight of MCTX both purified and in venom is 6,777 to 8,000 daltons. Smaller than expected molecular weights suggest protein fragmentation or side chain modifications. Smaller than expected molecular weights suggest protein fragmentation. Current analytical techniques allow for limited structural identification of the number and location of oxidized residues being added to the protein and rely heavily on previously published information and current chemical theory. Amino acid analyzers do not recognize unnatural amino acids and have limited capabilities for this application.
Example 3
[0046] Toxicity Assay in Mice
[0047] The endpoint of the above reactions are most easily determined by assessing the toxicity of the preparation in mice. Mice are sensitive to the actions of many venoms particularly to that of snakes. The proven LD50 of pure alpha-cobratoxin in mice is 1.2 mcg with death observable within hours when injected subcutaneously or intraperitoneally. If the animal survives overnight it is accepted that the material is not lethal and defines the endpoint of the assay. By administering the composition of the invention at set periods a reduction in the material's toxicity can be observed as an increase in time to death. When 5 mg of the protein solution can be administered without inducing death then the reaction process is complete. This represents more than a 4000 fold reduction in toxicity. It is at this point that the solution takes on its antiviral properties and native cobratoxin does not demonstrate antiviral activity in similar assays.
Examples 4
[0048] Antiviral Experiments with Modified Venom and Neurotoxin.
[0049] Based upon findings that modified snake alpha-neurotoxins have lymphocyte chemotaxic functions, as well as an observed amino acid sequence homology between HIV-1 gp120 and cobratoxin, the ability of oxidized venom and the purified alpha-cobratoxin to block in vitro HIV-1 infection in a thymus explant system and in PHA stimulated PBMC was examined. PHA stimulated PBMC were infected with a TCID 50 of 200 and 1000 of virus (R5 isolate HIV-1 Bal or X4 isolate HIV-1 Lai ).
[0050] Both formulations demonstrate inhibition of the virus. However, the crude venom preparation unexpectedly demonstrated a higher inhibitory activity than that of the purified neurotoxin.
[0051] As a generalized procedure for the two laboratories involved in the in vitro testing of oxidized purfied alpha neurotoxin and oxidized venom, the following was performed: PBMC from fresh, HIV-1 non-infected buffy coat cells obtained from healthy donors at local blood banks were purified by the Ficoll method. The buffy coat cells were maintained at room temperature until centrifugation. Purified PBMC were re-suspended at 1E6-3E6 cells/mL RPMI medium supplemented with 10% human AB serum and immediately treated with 5 ug PHA/mL suspension. Two to three days later, cells were counted and used for examination of infection. As a standard procedure, cells were incubated in propagation media, consisting of RPMI media supplemented with 10% human AB serum and 50 units IL2/mL, at a density of 6E6 cells per mL and incubated with 200-1000 TCID 50 HIV-1/mL×10E6 PBMC. Infection was allowed for 2 hours at 37° C. and the unbound virus was washed away by two washes with propagation media. 200,000 cells were suspended in 180 uL of propagation media and placed in 96 well plates (U bottom). Twenty uL of a 10× stock of the corresponding dilution of the drug was added to each well. Infections were performed in triplicate and controls containing 1 uM AZT were run in parallel as controls to confirm the validity of the assay. The cultures were incubated at 37° C. for 4 days. At that time, 90 uL of media was removed and replaced with 100 uL of propagation media containing the corresponding dilution of drug. The amount of p24 accumulated in the culture was estimated 3 days later (7 days post infection) with a Becton-Dickenson p24 ELISA. Routinely, a few samples were chosen and 10E-2 to 10E-4 dilutions of culture supernatant were prepared to estimate the linearity of the assay.
Example 5
[0052] Preliminary Studies in Patients with HIV by Parenteral Administration.
[0053] Based upon the broad antiviral activity of the modified cobra venoms and the purified alpha-cobratoxin concomitant with the proven safety data in prior human trials a preliminary study was undertaken.
[0054] Twenty (20) HIV positive patients volunteered to undergo treatment with the oxidized alpha-cobratoxin in addition to ten (10) HIV negative individuals over a period of 6 months. The modified cobratoxin was their sole therapy regime. Given the severity of the disease in this patient cohort no HIV positive placebo was examined. The drug was administered initially at 1 mcg per day (drug format was 10 mcg/ml in 0.9% saline) increasing daily in 0.1 cc increments to 10 mcg/day and subsequently rising to 20 mcg/day (administered as 1 cc b.i.d.). The participants were supplied with insulin-type syringes and taught to self-administer the drug. The participants presented themselves regularly for blood draws. Full blood analysis was undertaken and the data recorded.
[0055] No adverse events were reported in normal patients. General responses in HIV positive patients were good with one reported adverse event in a French female aged approximately 28 who was unavailable for follow-up investigations. Notable observations within 2-3 weeks of treatment were improved energy and strength, improved appetite and cessation of diarrhea episodes. Several patients were noted to have increased in weight by over 15 pounds. General activity increased with several patients returning to full employment.
[0056] The T4/T8 ratios were recorded and reported in FIG. 1 . In normal individuals the ratio is 1. The curves presented represent a least squares linear regression of the available data for each individual over the period of testing for that individual. Overall the general trend of the ratios was to increase over the course of treatment in the majority of HIV-1 positive patients.
Example 6
[0057] Preliminary Studies in Patients with HIV by Oral Administration.
[0058] Seven individuals self-administered the MCTX using a buccal spray composed of 600 mcg/mL saline. The protocol provided for the administration of the drug at 0.1 ml seven times per day giving a maximum drug level of 0.7 ml (600 mcg/ml)×50% (efficiency of oral delivery)=210 mcg per day over the course of 3 months. Data obtained for this study suggest MCTX had a noticeable effect in three areas: The percentage of HIV-1 infected T cells, the percentage of HIV-1 infected monocytes and percentage Plasma Viral Load. In all three cases, there was a general trend in the majority of patients toward a decrease in infected cells and plasma viral load, some by as much as 40%. | The present invention relates to a class of proteins, a process of production thereof, and a method for treatment of neurological and viral diseases in humans and animals. More specifically it applies to the treatment of heretofore intractable diseases such as retro-viral infections including human immunodeficiency virus (HIV), simian immunodeficiency virus (SIV), feline immunodeficiency virus (FIV), bovine immunodeficiency virus (BIV) and equine acquired immunodeficiency virus (EAIV). The | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method of and an apparatus for manufacturing a semiconductor device. More particularly, the method of manufacturing a semiconductor device according to the invention is applicable to a low pressure CVD (chemical vapor deposition) for example SiN, SiO 2 , amorphous Si, poly-Si or the like, etching, ashing of resist and cleaning of a reaction tube. In the description the wording “etching” refers to dry cleaning for removing the native oxide film formed on the silicon exposed in a contact hole for burying an electrode material such as poly-Si, doped poly-Si, SiO 2 , SiN, SiON, TiSi 2 , WSi 2 or TiN, or the scum generated by reaction of the resist and silicon.
[0003] 2. Related Background Art
[0004] Vertical batch type heating furnaces include the hot wall type and the cold wall type. Hot wall type furnaces are described in Kazuo Maeda: “Beginner's Book 3: The Semiconductor Manufacturing System for Beginners”, Industrial Research Society, Jul. 5, 1999, 1st ed., 3rd plate, p. 125. Cold wall type furnaces are described in p.143 of the same book.
[0005] Initially, vertical type heating furnaces were designed to use a single wall reaction tube. However, as elimination of particles was rigorously required, double wall reaction tubes came into the scene so as to draw reaction gas from the annular gap to an exhaust port (“Vertical type CVD System ERECTUS”; ‘Electronic Materials’, March, 1986, SC-6, pp. 98-102).
[0006] The growth conditions in a hot wall double tube type vertical furnace as described for the prior art in U.S. Pat. No. 6,204,194 (Mar. 20, 2001), which was assigned to the applicant of the present patent application, include the number of wafers: 100 to 150, wafer intervals: 5 to 9 mm, flat zone length: 700 to 900 mm, intra-furnace pressure: 0.3 to 1 torr (40 to 133 Pa) and flow rate of introducing reaction gas into furnace: 3 to 7 m/sec (col. 1, 11. 34-43). In such a CVD condition of the prior art, a part of the reaction gas flowing vertically in the reaction tube is engulfed in surfaces from the peripheries of the wafers and hence the growth rate is restricted by the engulfment of the gas, which makes the growth rate slow. Therefore, in the above cited U.S. patent, a high-speed growth CVD is achieved by injecting the reaction gas in parallel with the surfaces of the wafers arranged vertically in the vertical batch processing heating furnace using a single wall reaction tube. In terms of reaction kinetics, under the condition of high temperature as diffusion rate-determining, all the reaction gas is injected at high speed in parallel with the wafer surfaces in order to accelerate a diffusion.
[0007] WO01/173832 Publication, which was applied by the applicant of the present patent application, proposes an improvement to a method of removing the native oxide film in a contact hole by means of etching gas that is excited by a microwave.
[0008] With the method described in the above cited patent document, the native oxide film, which is SiO 2 film, in a contact hole is removed typically by etching to 5 to 20 angstroms. SiO 2 is transformed into complex Si 6 (NH 4 ) 4 which can easily be decomposed and evaporated at low temperature. It is known that the complex producing reaction shows a high reaction rate at temperature between 10 and 25° C. but stops at 60° C.
[0009] U.S. Pat. No. 4,237,150, proposes a method of dissociating silane into atomic hydrogen and carbon and forming hydrogenated amorphous silicon film by heating silane at 1,400-1,600° C. in vacuum of 10 −6 to 10 −4 torr by means of tungsten or carbon foil.
[0010] A method of utilizing a hot heating medium (to be referred to as “hot gas dissociation method” hereinafter) similar to the one disclosed in the above quoted U.S. Pat. No. 4,237,150 is reported by Nishimura et. al of Japan Advanced Institute of Science and Technology in “The Bulletin of the Japan Society of Applied Physics”, Aut., 2001, 13P-P11. According to the report, the dissociation/utilization efficiency of reaction gas is high because such a heating medium has a catalytic effect. This method is also introduced to the public by Asahi Shinbun (newspaper), evening issue of Jan. 16, 2002, in an article entitled “Light for Reestablishing the Country by Electronics”. The method is referred to as “catalytic chemical vapor phase growth method” in the article.
[0011] It is said that, with a hot gas dissociation method, gas molecules are dissociated at a certain probability and seeds that are in some form or another are chemically adsorbed to the catalyst surface so that dissociation/adsorption seeds are thermally desorbed by the hot catalyst and emitted into the reaction space (The Achievement Reporting Session Document for Semiconductor Device Manufacturing Processes Using Cat-CVD Methods, Jun. 4, 2001, p.15). For SiH 4 and W catalysts, for instance, the term “hot” refers to 1,600° C. or above. Generally, the frequency of collision of a gas molecule with a solid surface is a function of the density (ng) of gas molecules. However, since the chemical formulas of dissociation/adsorption seeds are unknown, the frequency of collision of an SiH 4 molecule in the reaction space is calculated by using the molecule density of SiH 4 and the actual result of CVD is observed in the above cited document.
[0012] With the method disclosed in the above cited U.S. Pat. No. 6,204,194, reaction gas is made to flow upward in the injection pipe and subsequently injected at high speed into the gap between the opposite surfaces of wafers by way of a large number of injection holes arranged at the lateral wall of the injection pipe. The flow rate of reaction gas is maximized when it passes through the injection holes. FIG. 1 of the accompanying drawings schematically illustrates the gas flow rate of this method. More specifically, FIG. 1 shows the gas flow rate relative to a horizontal position (horizontal axis) in a vertical reaction tube. While reaction gas is injected from the injection holes at high speed (see dotted line in FIG. 1), it is heated by a heater to produce particles, which are then blown into the reaction space to give rise to defects in the wafers, because reaction gas is driven to flow in the injection pipe at a relatively low rate.
[0013] Therefore, the first object of the present invention is to provide a low pressure CVD method using a vertical batch type heating furnace that can reduce the production of particles.
[0014] With the microwave-excited dry etching method, a microwave generator is arranged around a pipe made of Al 2 O 3 and/or SiO 2 and H 2 , N 2 , NF 3 or NF 3 +NH 3 is forced to flow through the pipe and excited by a microwave to produce etching gas of active seeds, which is then used for reaction. With this method, a microwave is not irradiated to NF 3 from the anti-particle point of view. Therefore, it reacts with microwave-excited H 2 so as to be transformed into active seeds showing a strong etching effect in order to remove native oxide film. However, it secondarily reacts with Al 2 O 3 and SiO 2 . Al and Si are produced to give rise to particles as a result of the secondary reaction. Additionally, a large volume of NF 3 is required with this method because NF 3 that is to be activated is not directly excited by a microwave.
[0015] Therefore, the second object of the present invention is to provide a method of removing native oxide film by producing a complex that can reduce the rate of consumption of gas containing halogen atoms.
[0016] While a hot gas dissociation method is attracting attention because it can be applied to large surface area wafers and involves a cold process, it is basically used with a single wafer system and no batch system has been realized for it to date. Therefore, the third object of the present invention is to provide a batch type hot gas dissociation system.
[0017] Furthermore, when dissociating an oxidizing agent by means of a hot gas dissociation method, a fierce reaction takes place on the catalyst to give rise to a problem of degrading the catalyst. Therefore, the fourth object of the present invention is to provide a batch type hot gas dissociation system that can produce oxide film.
SUMMARY OF THE INVENTION
[0018] According to the invention, the first object is achieved by providing a semiconductor device manufacturing method using a low pressure CVD to dissolve the particle problem, the method comprising: flatly laying two or more than two semiconductor substrates one above another substantially at regular intervals in a single wall reaction tube surrounding the lateral sides of a substrate holding jig and closed at the top so as to be able to remove substrates from the jig, the substrates including or not including dummy wafers; arranging the semiconductor substrates in a vertical type heating furnace provided with a heating means; and bringing the semiconductor substrates into contact with processing gas; the flow rate of gas flowing through a gas injection pipe extending vertically between the single wall reaction tube and the substrate holding jig and the flow rate of gas flowing through a gas exhaust pipe extending vertically between the single wall reaction tube and the substrate holding jig being made substantially equal to each other.
[0019] Referring to FIG. 1, the gas flow rates of gases flowing through the respective tubes are made to show a relationship of V 2 ′>>V 1 ′ with conventional methods but V 2 ≠V 1 according to the present invention. Although the relationship tends to be V 2 >V 1 under the influence of the exhaust pump, the difference is preferably not greater than five times. The gas flow rates increase as the gap separating wafers is reduced (see dotted lines (1) and (2)).
[0020] Particles can be reduced by raising the gas flow rates of gases flowing through wafers when the relationship of V 2 ≠V 1 is established because the reaction rate is raised for the reason of the principle described in the above cited U.S. Pat. No. 6,204,194.
[0021] The second and third objects of the invention are achieved by providing a hot gas dissociation system comprising: a substrate holding jig adapted to removably arranging two or more than two semiconductor substrates substantially at regular intervals greater than the mean free path of gas in a reaction tube, the substrates including or not including dummy wafers; a heating means attached, if necessary, to the reaction tube in order to heat the semiconductor substrates; a gas injection means for injecting gas into the reaction tube; an exhaust means for exhausting gas to the outside of the reaction tube; and a heating/catalyzing means for dissociating gas before or after injecting gas from the injection means.
[0022] Note that gas to be used in a hot gas dissociation system in order to achieve the second object includes halogen-containing gas for removing native oxide film.
[0023] The fourth object of the invention is achieved by providing a hot gas dissociation system comprising: a substrate holding jig adapted to removably arranging one or more than one semiconductor substrates in a reaction tube, the substrates including or not including dummy wafers; a heating means attached, if necessary, to the reaction tube in order to heat the semiconductor substrate; a first gas injection means for injecting a first gas other than an oxidizing agent into the reaction tube; a first heating/catalyzing means for dissociating the first gas before or after injecting gas from the gas injection means; a second gas injection means for injecting a second gas of an oxidizing agent into the reaction tube; a second heating/catalyzing means of iridium, vanadium or an Fe—Cr—Al type electric resistor alloy for dissociating the second gas before or after injecting gas from the first gas injecting means; and an exhaust means for exhausting the first and second gases to the outside of the reaction tube; the first gas injection means and the second gas injection means being oriented so as to cause the first and second gases to be mixed with each other after dissociation by the respective catalysts.
[0024] There are various different modes of realization for the gas injection means and the exhaust means to be used for a low pressure CVD method according to the invention.
[0025] For instance, the gas injection means may be a pipe extending vertically in the reaction tube and provided at the lateral wall thereof with injection holes and the exhaust means may be a pipe extending vertically in the reaction tube and provided at the lateral wall thereof with suction holes. In this case, the substrate holding jig holds semiconductor substrates that are flatly stacked in the furnace.
[0026] In another mode of realization, the gas injection means has an opening at a lower part of the reaction tube and the exhaust means is an annular gap formed between the reaction tube and an outer tube coaxially surrounding the reaction tube. In this mode of realization, the exhaust gas flow path formed by utilizing the annular gap can be made to show a large gas conductance.
[0027] In still another mode of realization, the gas injection means is a pipe having an opening at the lateral wall of the reaction tube and the gas exhaust means is an exhaust pipe having an opening at the lateral wall of the reaction tube. In this mode of realization, it is preferable that the vertical position of the gas injection pipe and that of the exhaust pipe substantially agree with each other.
[0028] Additionally, there are various mode of realization for the heating/catalyzing means that is used to achieve any of the second through fourth objects of the invention. For instance, the heating/catalyzing means may be arranged to face the injection holes in the reaction tube. In this mode of realization, a heat shield plate is preferably arranged between the heating/catalyzing means and the semiconductor substrates. In another mode of realization, the heating/catalyzing means may be arranged in the gas injection pipe.
[0029] No heating means such as heater or lamp is required for a hot gas dissociation system according to the invention where the system is applied to an etching or an ashing of resists because dissociated gas heats wafers to 200 to 300° C. However, in the other application a heating means such as heater or lamp may be provided by referring to the heating temperature, which will be described hereinafter.
[0030] The mean free path (λ) of gas that is innegligible to achieve the second and third objects of the present invention is expressed by the formula shown below;
λ∝T/d species 2 ·Pg,
[0031] where T represents temperature (K), d species represents the gas diameter (m) and Pg represents the gas pressure (Pa).
[0032] The mean free path (cm) of hydrogen (d species=2.75×10 −10 ) and that of silane (d species=m) are shown in the table below.
TABLE 1 Pg = 0.1 Torr (13.3 Pa) Tg H 2 SiH 4 0° C. 0.084 0.0106 (cm) 2000° C. 0.70 0.0878 (cm)
[0033] The hot gas dissociation method shows a high gas utilization efficiency if compared with the plasma CVD method. This means that the collision frequency (ncol) of gas molecules with substrates is high. The collision frequency (ncol) of gas molecules with a plurality of wafers needs to be uniform for uniformly forming film on the wafers.
[0034] [0034]FIGS. 2A and 2B schematically illustrate collisions of gas molecules with a pair of substrates. FIG. 2A shows an instance where the gap (d 1 ) separating the wafers<the mean free path (λ), whereas FIG. 2B shows an instance where the gap (d 2 ) separating the wafers>the mean free path (λ). The probability that gas molecules collide with each other before they collide with either of the substrates is higher in the case of FIG. 2A than in the case of FIG. 2B. The instance of FIG. 2A is not desirable because the collision frequency of gas molecules with the substrates is uneven and molecules easily regain a ground state from an active state. Although the phenomenon of FIGS. 2A and 2B can take place with plasma CVD, it appears more remarkably with a hot gas dissociation method. For the above described reason, in a hot gas dissociation system according to the invention, the gap separating wafers is made not smaller than the mean free path (λ) of gas (d>λ). However, d>>λ is not senseless because it requires a huge reaction space. Therefore, it is preferable that d=1 to 3λ.
[0035] Gas that is to be dissociated by the heating/catalyzing means is selected from substances other than oxidizing agents. Examples of such substances include SiH 4 , Si 2 H 6 , SiH 2 Cl 2 , TEOS, TMOP, NH 3 , PH 3 , B 2 H 6 , H 2 , N 2 , Cl 2 , F, SiCl 4 , BBr, AsH 3 , PCl 3 , BCl 3 , WF 6 , TiCl 3 , SiCl 4 , GeCl 4 , NF 3 , SF 6 and CF 3 . They also include TEOS containing oxygen in the compound. Oxidizing agents such as NO 2 , O 2 , CO 2 and O 3 as well as O 2 and O 3 gases that are excited by a high frequency wave of 2.5 GHz, for instance, (also referred to as remote plasma gas) are not dissociated and the third mode of carrying out the present invention as defined in claim 9 is provided with a separate injection means for injecting such an oxidizing agent.
[0036] Unlike the arrangement of claim 9, in a semiconductor device manufacturing system for achieving the fourth object of the invention, iridium, vanadium or an Fe—Cr—Al type electric resistor alloy, which is well known as Kanthal, is used as oxidizing agent heating/catalyzing means in order to prevent the heater from degrading.
[0037] Gases that can be used for the purpose of the present invention will be described further.
[0038] Gases that can be used to achieve the first object of the invention include those well known in the field of CVD and diffusion.
[0039] Gases that can be used to achieve the third object of the invention and their reaction temperatures are listed below.
[0040] (a) combination of Si 3 N 4 film: SiH 4 and NH 3 (reaction temperature: 750 to 800° C.), combination of SiH 2 Cl 2 and NH 3 (reaction temperature: 750 to 800° C.)
[0041] (b) poly-Si film: SiH 4 (580 to 625° C.), Si 2 H 6 (500 to 550° C.)
[0042] (c) combination of p-doped poly-Si film: SiH 4 and PH 3 (550 to 600° C.)
[0043] For forming oxide film to achieve the third object of the invention, the oxidizing agent is not dissociated by a W heater and is made to react with dissociation gas such as SiH 4 . However, TEOS that contains oxygen in the compound is dissociated by a W heater. To achieve the fourth object of the invention, the oxidizing agent is dissociated by an iridium heater. The oxidizing agent can be selected from a group including NO 2 , O 2 , CO 2 and O 3 . Particularly preferable combinations are listed below.
[0044] (d) SiO 2 film: SiH 4 and NO 2 (about 800° C.), SiH 4 and O 2 (300 to 400° C.), SiH 4 and CO 2 (900 to 1,000° C.), TEOS and O 2 (650 to 670° C.), TEOS (300 to 400° C.), TEOS and O 3 (350 to 400° C.)
[0045] (e) combination of SiON film: SiH 2 Cl 2 , NH 3 and O 2 (700 to 800° C.)
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] [0046]FIG. 1 is a schematic illustration of gas flow rate of a method according to the present invention and a conventional method;
[0047] [0047]FIGS. 2A and 2B are schematic illustrations of gas molecules moving between a pair of substrates;
[0048] [0048]FIG. 3 is a schematic cross sectional view of a batch processing vertical furnace of the single wall tube type to be used with the first method according to the present invention;
[0049] [0049]FIG. 4 is a schematic cross sectional plan view taken along and viewed in the direction of arrows A-A in FIG. 3;
[0050] [0050]FIGS. 5A, 5B and 5 C are respectively a longitudinal view and front views of a reaction gas injection pipe that can be used for the purpose of the invention;
[0051] [0051]FIG. 6 is a schematic cross sectional view of a heating/catalyzing means that can be used for the second through fourth inventions;
[0052] [0052]FIG. 7 is a schematic cross sectional view of another heating/catalyzing means;
[0053] [0053]FIG. 8 is a schematic cross sectional view of still another heating/catalyzing means;
[0054] [0054]FIG. 9 is a schematic longitudinal cross sectional view of a lamp heater that can be used for the purpose of the invention;
[0055] [0055]FIG. 10 is a schematic cross sectional view taken along and viewed in the direction of arrows E-E in FIG. 9;
[0056] [0056]FIG. 11 is a schematic view of another embodiment of semiconductor device manufacturing system realized to achieve the second object of the invention;
[0057] [0057]FIG. 12 is a schematic view of the hot gas dissociation system of the embodiment of FIG. 11;
[0058] [0058]FIG. 13 is a schematic cross sectional view taken along and viewed in the direction of arrows A-A in FIG. 11;
[0059] [0059]FIG. 14 is a schematic view of another system realized to achieve the fourth object of the invention;
[0060] [0060]FIG. 15 is a schematic cross sectional plan view of a system realized to achieve the third and fourth objects of the invention; and
[0061] [0061]FIG. 16 is a schematic longitudinal cross sectional view of the system of FIG. 15.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0062] Now, the present invention will be described in greater detail by referring to the accompanying drawings that illustrate preferred embodiments of the present invention.
[0063] [0063]FIGS. 3 and 4 schematically illustrate a system for carrying out the first method of the present invention. Referring to FIGS. 3 and 4, reference symbol 1 denotes the furnace body of a vertical type heating furnace. It is made of fire-resistant and heat-resistant materials and shows a pot-like profile specific to a hot wall furnace closed at the top and open at the bottom. Reference symbol 2 denotes a heating means, or heater, rigidly secured to the inner wall of the furnace body 1 by means of an appropriate jig. The heater 2 is divided into a number of zones, the electric currents supplied to the respective zones are controlled independently. Although not illustrated in detail, current meters V 20 , V 30 are arranged at lower positions of the furnace body 1 and the heater 2 .
[0064] Reference symbol 5 denotes a tower type substrate holding jig that is entirely supported by a lower center shaft 11 so as to be vertically movable and rotatable in the furnace space. The substrate holding jig 5 needs to be rotated when the processing temperature is not higher than 150° C. When the processing temperature is between 350 and 450° C., it is possible to achieve an intra-planar thickness distribution of 5 to 10% without rotating the jig 5 . Reference symbol 3 denotes wafers. One or more than one top wafers and/or one or more than one bottom wafers may be dummy wafers. The gap separating two adjacently located wafers is preferably 5 to 15 mm, more preferably about 10 mm, for 8-inch wafers. A number of annular sections 6 are stacked at regular intervals and rigidly secured to a support column 7 in order to vertically arrange and support wafers 3 . Each annular section 6 is provided with four claws 8 that are arranged at regular intervals of 90° and projecting horizontally toward the central axis of the furnace to hold the peripheral edge of a wafer 3 .
[0065] Reference symbol 10 denotes a base section for rigidly securing the bottom end of the support column 7 . The base section 10 may be a hollow body containing vacuum in the inside. The lower center shaft 11 rigidly fitted to the bottom of the base section 10 is linked to a lifting/rotating mechanism (not shown) through a removable center hole of a bottom plate 12 .
[0066] Reference symbol 13 denotes a quartz-made single wall type reaction tube (to be referred to simply as “reaction tube” hereinafter). A reaction space is provided in the inside. Reference symbol 20 denotes a reaction gas injection pipe and reference symbol 30 denotes reaction gas exhaust pipe. The reaction gas injection pipe 20 is provided with a pair of pipe bodies and the reaction gas exhaust pipe 30 is also provided with a pair of pipe bodies.
[0067] The reaction gas injection pipe 20 preferably has an inner diameter not less than 10 mm. Each pipe body of the reaction gas injection pipe 20 has an introducing section 20 a , a low pressure section 20 b and an injecting section 20 c that are arranged continuously in the mentioned order. The introducing section 20 a is provided with a valve 21 to block any inflow of reaction gas after the end of reaction. During a CVD growth period, the valves 21 of the reaction gas injection pipe 20 is operated so as to be opened and closed to define the conductance in the furnace corresponding to the capacity of the pumps arranged in the reaction gas exhaust pipe 30 . The next low pressure section 20 b is located off a red-hot region and adapted to reduce the internal pressure and increase the gas flow rate so as to realize a condition of V 2 ≠V 1 as the inner diameter of the tube is rapidly increased there.
[0068] Finally, the injecting section 20 c extends vertically in the furnace so as to uniformly deliver reaction gas to the stacked wafers 3 in the furnace through injection holes 23 . Some different modes of realizing injection holes 23 will be discussed below.
[0069] For instance, the front end of the reaction gas injection pipe 20 is closed and reaction gas is injected through the injection holes arranged at the lateral wall of the pipe. In this mode, the total cross sectional area (S 1 ) of the injection holes 23 is made greater than the cross section area (S 2 ) of the reaction gas injection pipe 20 C (S 1 >S 2 ) in order to avoid any increase in the gas flow rate due to compressed gas because the inside of a single wall type reaction tube 13 is located closer to the exhaust pump than to the inside of the reaction gas injection pipe 20 and hence the flow rate of reaction gas tends to increase in the single wall type reaction tube 13 .
[0070] In another mode, the front end of the reaction gas injection pipe 20 is not closed but made to be an open end 32 (FIG. 3). Since the cross sectional area (S 1 ′) of the open end 32 provides an effect same as the cross sectional area (S 1 ) of the injection holes, any increase in the gas flow rate due to compressed gas can be avoided when S 1 +S 1 ′>S 2 . The value of the left side of the formula can be increased when the front end of the reaction gas injection pipe is broadened.
[0071] In still another mode, the front end of the reaction gas injection pipe 20 is made to be an open end 32 and all the injection holes 23 are closed. Thus, in this mode, reaction gas is injected from the open end 32 .
[0072] The reaction gas exhaust pipe 30 is an L-shaped pipe provided at the exit side thereof with a valve 31 and at the front end thereof with a suction hole 32 . It is also provided at the lateral wall thereof with suction holes 33 and is connected to an exhaust pump (not shown).
[0073] Current meters V 20 , V 30 are arranged at corresponding positions of the reaction gas injection pipe 20 and the reaction gas exhaust pipe 30 to gauge the respective gas flow rates.
[0074] As shown in FIG. 4, a pair of pipe bodies 20 (1) , 20 (2) may be arranged side by side for the reaction gas injection pipe 20 . The pipe bodies 20 (1) , 20 (2) may have a same length or different respective lengths. Then, different types of gas may be made to flow through the respective pipe bodies 20 (1) , 20 (2) having a same length. Reaction gas can be made to flow only to upper wafer(s) or lower wafer(s) by means of pipe bodies 20 (1) , 20 (2) having different respective lengths.
[0075] Similarly, a pair of pipe bodies 30 (1) , 30 (2) may be arranged side by side for the reaction gas exhaust pipe 30 .
[0076] [0076]FIGS. 5A through 5C illustrate a reaction gas injection pipe 20 whose front end is closed.
[0077] [0077]FIG. 5A is a cross sectional view and FIGS. 5B and 5C are front views of different reaction gas injection pipes 20 . As shown in FIG. 5B, three injection holes 23 have different cross sectional areas with the (upper) one located close to the front end having a large triangular cross section and the (lower) one located close to the rear end having a small triangular cross section. Each injection hole 23 shows an inverted triangular contour and hence has a larger area in an upper section and smaller area in a lower section. With such differentiated contours of the holes, the reaction gas injection holes can be made to inject reaction gas at a same flow rate regardless of their vertical positions. The same effect is achieved by arranging injection holes 23 having a same contour and a same size in a manner as shown in FIG. 5C.
[0078] [0078]FIG. 6 is a schematic cross sectional view of a vertical batch processing heating furnace similar to the one shown in FIG. 3 but shows only the reaction gas injection pipe 20 and the reaction gas exhaust pipe 30 . The same components are denoted respectively by the same reference symbols. With the hot gas dissociation method that is used with the arrangement of FIG. 6, reaction gas is brought into contact with a heater (heating/catalyzing means) 26 made of a wire of tungsten, molybdenum, tantalum, Kanthal (trade name: available from Gadelius AB) or iridium which may or may not be coated with Al 2 O 3 (to be referred to as “tungsten heater 26 ” hereinafter) to produce a reaction gas dissociation phenomenon as described above in “Related Background Art” and subsequently inject reaction gas through the injection holes 23 for batch processing. The internal pressure of the low pressure section 20 b is preferably 1 to 20 Pa.
[0079] Thus, a system that can achieve the second through fourth objects of the invention can be realized by using the structure of the system of FIG. 3 and modifying it in a manner as illustrated in FIG. 6. Note, however, the following points have to be taken into consideration.
[0080] (a) When the tungsten heater 26 and the wafers 3 are separated from each other by a short distance and the reaction temperature is low, the heater 2 (heating/catalyzing means) is not necessary because the wafers 3 can be heated to reaction temperature by the tungsten heater 26 .
[0081] (b) The oxidizing agent and the gas other than the oxidizing agent need to be injected separately from the respective pipe bodies 20 (1) , 20 (2) in order to achieve the third object of the invention.
[0082] (c) One, two or more than two wafers are processed by thermally dissociating etching gas for removing native oxide film in order to achieve the second object of the invention.
[0083] The reaction conditions that has to be satisfied when a hot heating medium such as W is used include the following.
[0084] (1) Etching of Si, SiO 2 , SiN Using NF 3 , SF 6 , CHF 3 :
[0085] diluted medium: He, electrically energized heating temperature: 2,400° C., pressure: 67 Pa, NF 3 flow rate: 70 sccm (as reported at the above cited Japan Society of Applied Physics).
[0086] (2) CVD of Undoped Hydrogenated Microcrystalline Si:
[0087] SiH 4 flow rate: 2 to 15, heater area: 3 to 50 cm 2 , gas pressure: 0.1 to 13 Pa, substrate temperature: 200 to 300° C., filament temperature: 1,500° C., W filament surface area: 4 cm 2 , (Extended Abstract of the International Pre-workshop on Cat-CVD (Hot-Wide CVD) Process, 1999, 9, 29, Ishikawa Hitech Center, p. 55).
[0088] (3) Amorphous Si:
[0089] heater temperature: 1,500 to 1,900° C., SiH 4 flow rate: 10 to 20 sccm, H 2 flow rate: 10 to 40 sccm, heater power: 100 to 600 W, heater area: 5 to 30 cm 2 , gas pressure: 0.1 to 13 Pa, substrate temperature: 150 to 300° C. (Extended Abstract, 1st International Conference on Cat-CVD (Hot-Wide CVD) Process, 2000 , 11 , 14 - 17 , Kanazawa City).
[0090] (4) Poly-Si:
[0091] heater temperature: 1,500 to 1,900° C., SiH 4 flow rate: 0.5 to 10 sccm, H 2 flow rate: 0 to 200 sccm, heater power: 800 to 1,500 W, heater area: 10 to 60 cm 2 , gas pressure: 0.1 to 40 Pa, substrate temperature: 300 to 450° C. (same as (3)).
[0092] (5) SiN x :
[0093] heater temperature: 1,500 to 1,900° C., SiH 4 flow rate: 0.5 to 5 sccm, NH 3 flow rate: 50 to 200 sccm, heater power: 300 to 800 W, heater area: 5 to 30 cm 2 , gas pressure: 0.1 to 13 Pa, substrate temperature: 200 to 300° C. (same as (3)).
[0094] (6) Ashing of Resist:
[0095] H 2 O, O 2 gas (as reported at the above cited Japan Society of Applied Physics).
[0096] [0096]FIG. 7 is a schematic cross sectional view of a tungsten heater that can be used for the purpose of the invention and whose profile and arrangement are different from those of FIG. 6. The tungsten heater 26 is arranged between the reaction gas injection pipe 20 and the wafer holding jig. The tungsten heater 26 is guided in a sleeve 27 such as a quarts tube and then extended to the outside of the sleeve 27 to show a U-shaped profile in a hot section that is necessary for the reaction ( 26 a ). Reaction gas injected from the injection holes 23 is brought to contact with the tungsten heater 26 a and subsequently forms a film on the wafers. In the sleeve 27 , a gap is formed between the tungsten heater 26 and the sleeve 27 . Gas such as N 2 or NH 3 may be made to flow through the gap in order to protect the tungsten heater 26 . The tungsten heater 26 may be made to show a larger diameter in the sleeve 27 than at the outside of the sleeve 27 .
[0097] [0097]FIG. 8 is a schematic transversal cross sectional view of a vertical type furnace whose profile and arrangement are different from those of FIG. 6 and those of FIG. 7. The substrate holding jig is not shown in FIG. 8. The tungsten heater 26 is arranged between a pair of parallel pipe bodies 20 (1) , 20 (2) of the reaction gas injection pipe 20 and adapted to heat and dissociate gas 28 , which may typically be silane. Then, it supplies reaction gas that is obtained by dissociation toward the wafers 3 . A block plate 29 is arranged to focus the flow of reaction gas produced by dissociation on the tungsten heater 26 and the wafers 3 .
[0098] Beside the parallel pipe bodies 20 (1) , 20 (2) , a separate oxidizing agent injection pipe may be arranged at an appropriate position in the furnace in order to grow SiO 2 film.
[0099] [0099]FIGS. 9 and 10 schematically illustrate an arrangement of lamp heating suited for a reaction conducted at a temperature range below that of 350 to 450° C., particularly at a temperature range between 150 and 300° C., in order to achieve the first object of the invention. Note that only the positions of current meters V 20 , V 30 are shown.
[0100] In FIGS. 9 and 10, the components same as those of FIGS. 3 and 4 are denoted respectively by the same reference symbols. In FIGS. 9 and 10, reference symbol 40 a denotes rod-shaped heating lamps arranged circularly and reference symbol 41 denotes a reflector panel coated with gold (Au) foil, whereas reference symbol 42 denotes a jacket. Cooling water is made to flow between the reflector panel 41 and the jacket 42 . Reference symbol 40 b denotes a winding lamp heater on the ceiling. Additionally, a purge gas injection pipe 50 for driving out gas in the furnace after the treatment and a separator 51 for protecting a lower part against heat in the furnace are arranged.
[0101] A reflector panel 52 is arranged in the base section 10 in order to reflect heat in the furnace and improve the uniform temperature distribution in the reaction space. Additionally, a top facet quart plate 53 is arranged above the uppermost wafer 3 to raise the hotness of the reaction space.
[0102] [0102]FIGS. 11 through 13 schematically illustrate another embodiment of semiconductor device manufacturing system suited for etching native oxide film and adapted to achieve the second object of the invention. In FIGS. 11 through 13, the components same as those of FIGS. 3 and 4 are denoted respectively by the same reference symbols. Note, however, that the reaction gas injection pipe 20 and the reaction gas exhaust pipe 30 are arranged in parallel with each other in a transversal direction and the reaction tube 13 and the pipes 20 , 30 are made of aluminum. Aluminum reacts with N 2 , H 2 and NF 3 to form a stable and inactive film and hence can minimize the production of particles. Additionally, since NF 3 is dissociated and activated by the tungsten heater 26 , its consumption rate is low.
[0103] The tungsten heater 26 shows a profile of a large number of tightly arranged W-shaped patterns as viewed in the direction of gas flow. The rate of reaction of removing native oxide film by excited NF 3 remarkably falls at 60° C. as pointed out earlier and therefore it is necessary to protect the wafers 3 from being heated to such a temperature level by the tungsten heater 26 . A light shield plate 35 is arranged between the tungsten heater 26 and the substrate holding jig 6 in order to protect the wafers 3 against being heated by radiation of heat. On the other hand, a gap is left between the top section of the light shield plate 35 and the inner wall of the reaction tube 13 so that excited NF 3 may get to the wafers 3 by way of the gap. Preferably, the light shield plate 35 has a water cooling structure in the inside so that it may operates as jacket. All the wafers 3 are driven to rotate as the rotary force of the motor 36 is transmitted to the lower center shaft 11 by way of a gear 37 .
[0104] [0104]FIG. 14 is a schematic view of another system designed to achieve the fourth object of the invention. It is a cross sectional view similar to that of FIG. 8.
[0105] In FIG. 14, reference symbol 20 (1) denotes an injection pipe for injecting gas other than an oxidizing agent, or SiH 4 gas for instance, reference symbol 20 (2) denotes an injection pipe for injecting an oxidizing agent, or O 2 gas for instance, and reference symbol 26 (1) denotes a tungsten heater, while reference symbol 26 (2) denotes an iridium heater and reference symbol 45 denotes a block plate for preventing SiH 4 and O 2 from being mixed with each before dissociation.
[0106] [0106]FIGS. 15 and 16 schematically illustrate still another embodiment designed to achieve the fourth object of the invention. The components same as those of FIGS. 11 through 14 are denoted respectively by the same reference symbols. This system is characterized in that wafers 3 are held not by a grooved column by respective susceptors 39 that are stacked and rigidly secured to a rotary shaft 38 . A gas injection pipe 41 for injecting gas other than an oxidizing agent and an oxidizing agent injection pipe 42 are branched from the reaction tube 13 .
[0107] The iridium heater 26 (2) of the second embodiment is replaced by a remote plasma generator using a 2.45 GHz microwave. | A vertical single wall reaction tube type batch processing furnace can reduce the generation of particles. A method of removing native oxide film by fluoride gas can enhance the efficiency of utilization of gas. A method of exciting reaction gas by a catalyst at high temperature can be applied to a batch processing. A method of exciting reaction gas by a catalyst utilizes an oxidizing agent and gas other than an oxidizing agent. The flow rate of gas in the gas injection pipe and that of gas in the exhaust pipe are made to be substantially equal to each other. The gap between two adjacent wafers is made greater than the mean free path of gas. The oxidizing agent is dissociated by a catalyst of Ir, V or Kanthal while the gas other than the oxidizing agent is dissociated by a catalyst of W. | 7 |
TECHNICAL FIELD
The present invention relates to absorbable block copolymers having one of the blocks made from hard phase forming monomers and another of said blocks made from randomly copolymerized soft phase forming monomers, and more particularly to surgical articles made totally or in part therefrom, including both monofilament and multifilament sutures.
BACKGROUND OF THE INVENTION
Polymers and copolymers of, and surgical devices made from lactide and/or glycolide and/or related compounds are well-know. See, e.g., U.S. Pat. Nos. 2,668,162, 2,683,136, 2,703,316, 2,758,987, 3,225,766, 3,268,486, 3,268,487, 3,297,033, 3,422,181, 3,442,871, 3,463,158, 3,468,853, 3,531,561, 3,565,869, 3,597,449, 3,620,218, 3,626,948, 3,636,956, 3,736,646, 3,739,773, 3,772,420, 3,733,919, 3,781,349, 3,784,585, 3,792,010, 3,797,499, 3,839,297, 3,846,382, 3,867,190, 3,987,937, 3,878,284, 3,896,802, 3,902,497, 3,937,223, 3,982,543, 4,033,938, 4,045,418, 4,057,537, 4,060,089, 4,137,921, 4,157,437, 4,243,775, 4,246,904, 4,273,920, 4,275,813, 4,279,249, 4,300 ,565, and 4,744,365, U.K. Pat. or Appln. Nos. 779,291, 1,332,505, 1,414,600 and 2,102,827, D. K. Gilding et al., "Biodegradable polymers for use in surgery-polyglycolic/poly (lactic acid) homo-and copolymers: 1," Polymer, Volume 20, pages 1459-1464 (1979), and D. F. Williams (ed.) Biocompatibility Of Clinical Implant Materials, Volume II, chapter 9: "Biodegradable Polymers" (1981).
Surgical devices prepared from copolymers containing lactide or glycolide and trimethylene carbonate have been described.
U.S. Pat. No. 4,429,080 describes glycolide end blocks and glycolide trimethylene carbonate random copolymer middle blocks. The block copolymers described in the '080 patent contain no 1,4 dioxane-2-one.
As another example, U.S. Pat. No. 5,066,772 describes random copolymers of lactide and trimethylene carbonate and triblock copolymers having lactide end blocks and lactide-trimethylene carbonate random copolymer center blocks. The block copolymers of the '772 patent do not include a block which has predominantly glycolic acid ester linkages.
Block copolymers described in U.S. Pat. No. 5,145,945 do not include a block having random copolymers of trimethylene carbonate and caprolactone nor do they include a block which is predominantly glycolide. In addition, see U.S. Pat. Nos. 4,243,775; 4,300,565; 4,705,820; 4,891,263; 4,916,193; 4,902,203.
The present invention provides another bioabsorbable copolymer useful in the preparation of surgical articles such as sutures which exhibit desirable physical characteristics, such as knot pull strength and straight pull strength.
SUMMARY OF THE INVENTION
It has now been found that absorbable surgical articles may be formed from a block copolymer having one of the blocks made from hard phase forming monomers and another of the blocks made from random copolymers of soft phase forming monomers. Hard phase forming monomers include glycolide and lactide while soft phase forming monomers include 1,4 dioxane-2-one and 1,3 dioxane-2-one and caprolactone.
Preferably, block copolymers useful in forming surgical articles in accordance with the present invention include block copolymers comprising one block having glycolic acid ester units as a predominant component thereof. A "predominant component" is a component which is present is an amount greater than 50 percent.
In a particularly useful embodiment the block copolymers of the present invention may be spun into fibers. The fibers can be fabricated into both monofilament and braided multifilament sutures.
In another aspect of the present invention there is provided a process for manufacturing a suture exhibiting excellent energy and/or increased knot performance for a given size comprising the operations of extruding the block copolymer of the present invention at an extrusion temperature of from about 180° C. to about 245° C. to provide a monofilament fiber, stretching the solidified monofilament at a temperature of from about 30° C. to about 95° C. in water (or other suitable liquid medium) or at from about 40° C. to about 120° C. in air (or other suitable gaseous medium) at a stretch ratio of from about 3:1 to about 10:1 to provide a stretched monofilament. The stretched monofilament preferably is then frozen at a temperature of from about -15° C. to about 0° C. The suture then may be annealed with or without relaxation at a temperature of from about 80° C. to about 130° C. to provide the finished suture.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a schematic illustration of an apparatus which is suitable for manufacturing the monofilament suture of this invention; and,
FIG. 1B is a modification of the apparatus of FIG. 1A which is particularly suitable for manufacturing the monofilament sutures of the present invention of smaller size, e.g., sizes 4/0 and smaller.
FIG. 2 is a perspective view of a suture of the present invention attached to a needle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the present invention, it has been found that a block copolymer having two specific types of blocks, an "A" block having a proportion of glycolic acid ester units as the predominant component thereof and a "B" block comprising 1,3 dioxane-2-one randomly copolymerized with caprolactone, preferrably epsilon-caprolcatone, can advantageously be combined to form a block copolymer useful in forming surgical elements.
The block copolymer compositions of the present invention include an A block formed from a copolymer which has glycolide as the predominant component thereof. That is, glycolide comprises at least 50 mole percent of the first block. Preferably, glycolide comprises at least about 60 mole percent of the first block. Most preferably, the first block is a glycolide homopolymer. The glycolide may be copolymerized with any monomer which provides an absorbable copolymer to form the A block. Such monomers include but are not limited to lactide, trimethylene carbonate, p-dioxanone, and epsilon-caprolactone. The copolymers of glycolide which form the first block can be random or block copolymers and can be synthesized by known methods. See, for example. U.S. Pat. Nos. 4,653,497; 4,838,267; 4,429,080; 4,605,730; and 4,788,979 the disclosures of which are incorporated herein by reference.
The B block of the composition of this invention has epsilone-caprolactone and 1,3 dioxane-2-one linkages. Preferably epsilone-caprolactone comprises from about 20 mole percent to about 80 mole percent, and more preferrably from about 25 mole percent to about 50 mole percent of the B block. Most preferably, epsilone-caprolactone comprises at least about 30 mole percent of the B block, the remainder of the block comprising 1,3 dioxane-2-one. For purposes of the present invention, copolymers of 1,3 dioxane-2-one and epsilon-caprolactone having an inherent viscosity of from about 1.0 to about 1.5 dl/g measured at 30° C. and a concentration of 0.25 g/dl in chloroform may generally be used as the second block.
The block copolymers of this invention may be prepared by preparing the individual polymers which make up the blocks and then copolymerizing these polymers to form a block or graft copolymer. Alternatively, a polymer having epsilon-caprolatone and 1,3 dioxane-2-one linkages may be prepared in a reactor and then the monomers needed to form the other block or blocks are added directly to the reactor to thereby form the block copolymer.
In forming the block copolymers of this invention, the A (predominantly glycolide) block may be present in an amount from about 40 to about 75 percent by weight based on the weight of the final block copolymer. The B (random copolymer) block may be present in an amount from about 30 to about 50 weight percent based on the weight of the final block copolymer. Preferably, the A block comprises between about 50 and about 70 weight percent of the block copolymer. In a particularly useful embodiment, the A block comprises about 60 weight percent and the B block comprises about 40 weight percent of the final block copolymer. The copolymers of the present invention have a molecular weight such that their inherent viscosity is from about 0.8 to about 2.5 dl/g, and preferably from about 1.3 to about 1.8 dl/g measured at 30° C. at a concentration of 0.25 g/dl in hexafluoroisopranol (HFIP).
Each A and B block may comprise a single type of recurring monomeric unit. Alternatively, each block may comprise more than one type of recurring monomeric unit randomly distributed throughout each block. The block copolymers of the present invention may have repeating block units such as AB, ABA, ABAB, ABABA, BABA, etc.; with ABA being preferred.
The block copolymers of this invention can be formed into surgical articles using any know technique, such as, for example, extrusion, molding and/or solvent casting. The copolymers can be used alone, blended with other absorbable compositions, or in combination with non-absorbable components. A wide variety of surgical articles can be manufactured from the copolymer of the present invention. These include but are not limited to clips and other fasteners, staples, sutures, pins, screws, prosthetic devices, wound dressings, drug delivery devices, anastomosis rings, and other implantable devices. Fibers made from the copolymers of this invention can be knitted or woven with other fibers, either absorbable or nonabsorbable to form meshes or fabrics. The compositions of this invention can also be used as an absorbable coating for surgical devices. Preferably, however, the copolymers are spun into fibers to be used as sutures, either monofilament or multifilament.
Multifilament sutures of the present invention may be made by methods known in the art. Braid constructions such as those disclosed and claimed in U.S. Pat. Nos. 5,059,213 and 5,019,093 are suitable for the multifilament suture of the present invention.
A suitable process for the manufacture of monofilament sutures of the present invention comprises the operations of melt extruding the resin at an extrusion temperature of from about 180° C. to about 245° C. to provide a monofilament, stretching the solidified monofilament at a temperature of from about 30° C. to about 95° C. in water (or other suitable liquid medium) or at from about 30° C. to about 120° C. in air (or other suitable gaseous medium) at a stretch ratio of from about 3:1 to about 10:1 to provide a stretched monofilament. Optionally, the solidified monofilament may be stretched in air or other suitable gaseous medium preferrably at about 45° C. Preferably, the monofilament is then frozen at a temperature of from about -15° C. to about 0° C. The suture may then be annealed at a temperature of from about 80° C. to about 130° C. to provide the finished suture.
FIG. 1A schematically illustrates a monofilament suture manufacturing operation which is especially suitable for producing larger size sutures, e.g., those of sizes 2/0 and larger. Extruder unit 10 is of a known or conventional type and is equipped with controls for regulating the temperature of barrel 11 in various zones thereof, e.g., progressively higher temperatures in three consecutive zones A, B and C along the length of the barrel. Pellets or powder of resins of the present invention are introduced to the extruder through hopper 12. Any of the block copolymers of the present invention which are useful for the formation of fibers can be used herein.
Motor-driven metering pump 13 delivers melt extruded resin at a constant rate to spin pack 14 and thereafter through spinneret 15 possessing one or more orifices of desired diameter to provide a molten monofilament 16 which then enters quench bath 17, e.g., containing water, where the monofilament solidifies. The distance monofilament 16 travels after emerging from spinneret 15 to the point where it enters quench bath 17, i.e., the air gap, can vary and can advantageously be from about 2 to about 50 cm and preferably from about 1 to about 20 cm. If desired, a chimney (not shown), or shield, can be provided to isolate monofilament 16 from contact with air currents which might otherwise affect the cooling of the monofilament in an unpredictable manner. In general, barrel zone A of the extruder can be maintained at a temperature of from about 180° C. to 230° C., zone B at from about 190° C. to 240° C. and zone C at from about 200° C. to about 250° C. Additional temperature parameters include: metering pump block 13 at from about 190° C. to about 240° C., spin pack 14 at from about 200° C. to about 240° C., spinneret 15 at from about 190° C. to about 240° C. and quench bath at from about 10° C. to about 80° C.
Monofilament 16 is passed through quench bath 17 around driven roller 18 and over idle roller 19. Optionally, a wiper (not shown) may remove excess water from the monofilament as it is removed from quench bath 17. On exiting the quench bath the monofilament is wrapped around a first godet 21 provided with nip roll 22 to prevent slippage which might otherwise result from the subsequent stretching operation; and subsequently wrapped around godets 101, 102, 103 and 104 or any other suitable godet arrangement. Monofilament 16 passing from godet 104 is stretched, e.g., with stretch ratios on the order of from about 3:1 to about 10:1 and preferably from about 4:1 to about 7:1, to effect its orientation and thereby increase its tensile strength.
In the stretching operation shown in FIG. 1A, generally suitable for larger size sutures, e.g., sizes 2 to 2/0, monofilament 16 is drawn through hot water (or other suitable liquid medium) draw bath 23 by means of godets 24, 105, 106, 107 and 108 or any other suitable arrangement of godets which rotate at a higher speed than godet 104 to provide the desired stretch ratio. The temperature of hot water draw bath 23 is advantageously from about 30° C. to about 95° C. and preferably is from about 40° C. to about 60° C.
In the alternative stretching operation shown in FIG. 1B, generally preferred for smaller sutures sizes, e.g., sizes 3/0 to 9/0, monofilament 16 is drawn by godets 24, 105, 106, 107, and 108 or any other suitable godet arrangement through hot air convection oven chamber 23' at a temperature of from about 30° C. to about 120° C. and preferably from about 40° C. to about 70° C. to provide the desired amount of stretch. Following the stretching operation shown in FIG. 1A or 1B, monofilament 16 optionally may be subjected to an on-line annealing and/or additional stretching without shrinkage or relaxation with shrinkage operation as a result of which the monofilament shrinks. In the processes of FIGS. 1A and 1B, on line annealing with or without relaxation when desired is accomplished by driving monofilament 16 by godets 26, 109,110, 111, and 112 or any other suitable godet arrangement through second hot air oven chamber 25 at a temperature of from about 30° C. to about 120° C. and preferably from about 40° C. to about 60° C. During the relaxation process, at these temperatures, monofilament 16 will generally recover to within about 80 to about 97 percent, and preferably to within about 95 percent, of its pre-annealed length to provide the finished suture. For relaxation, the third godet rotates at a slower speed than the second godet thus relieving tension on the filament.
Annealing of the suture also may be accomplished without shrinkage of the suture. In carrying out the annealing operation, the desired length of suture may be wound around a creel and the creel placed in a heating cabinet maintained at the desired temperature, e.g. about 80° C. to about 130° C., as described in U.S. Pat. No. 3,630,205. After a suitable period of residency in the heating cabinet, e.g., about 18 hours or so, the suture will have undergone essentially no shrinkage. As shown in U.S. Pat. No. 3,630,205, the creel may be rotated within the heating cabinet in order to insure uniform heating of the monofilament or the cabinet may be of the circulating hot air or nitrogen type in which case uniform heating of the monofilament will be achieved without the need to rotate the creel. Thereafter, the creel with its annealed suture is removed from the heating cabinet and when returned to room temperature, the suture is removed from the creel, conveniently by cutting the wound monofilament at opposite ends of the creel. The annealed sutures, optionally attached to surgical needles, are then ready to be packaged and sterilized.
The suture of the present invention, suture 101, may be attached to a surgical needle 100 as shown in FIG. 2 by methods well known in the art. Wounds may be sutured by passing the needled suture through tissue to create wound closure. The needle preferably is then removed from the suture and the suture tied.
It is further within the scope of this invention to incorporate one or more medico-surgically useful substances into the present invention, e.g., those which accelerate or beneficially modify the healing process when particles are applied to a surgical repair site. So, for example, the suture can carry a therapeutic agent which will be deposited at the repair site. The therapeutic agent can be chosen for its antimicrobial properties, capability for promoting repair or reconstruction and/or new tissue growth. Antimicrobial agents such as broad spectrum antibiotic (gentamycin sulfate, erythromycin or derivatized glycopeptides) which are slowly released into the tissue can be applied in this manner to aid in combating clinical and sub-clinical infections in a tissue repair site. To promote repair and/or tissue growth, one or several growth promoting factors can be introduced into the sutures, e.g., fibroblast growth factor, bone growth factor, epidermal growth factor, platelet derived growth factor, macrophage derived growth factor, alveolar derived growth factor, monocyte derived growth factor, magainin, and so forth. Some therapeutic indications are: glycerol with tissue or kidney plasminogen activator to cause thrombosis, superoxide dimutase to scavenge tissue damaging free radicals, tumor necrosis factor for cancer therapy or colony stimulating factor and interferon, interleukin-2 or other lymphokine to enhance the immune system.
It is contemplated that it may be desirable to dye the sutures of the present invention in order to increase visibility of the suture in the surgical field. Dyes known to be suitable for incorporation in sutures can be used. Such dyes include but are not limited to carbon black, bone black, D&C Green No. 6, and D&C Violet No. 2 as described in the handbook of U.S. Colorants for Food, Drugs and Cosmetics by Daniel M. Marrion (1979). Preferably, sutures in accordance with the invention are dyed by adding up to about a few percent and preferably about 0.2% dye, such as D&C Violet No. 2 to the resin prior to extrusion.
In order that those skilled in the art may be better able to practice the present invention, the following examples are given as an illustration of the preparation of block copolymer of the present invention as well as of the preparation and superior characteristics of the sutures of the present invention. It should be noted that the invention is not limited to the specific details embodied in the examples and further that all ratios or parts recited are by weight.
EXAMPLE 1
1,3 dioxane-2-one (1090 grams) and epsilon-caprolactone (660 grams) are added to a reactor along with 1.0 grams of stannous octoate and 1 gram of diethylene glycol. The mixture is heated and placed at 160° C., with stirring under a nitrogen atmosphere for 3.5 hours. The epsilone-caprolactone/1,3 dioxane-2-one copolymer is then sampled.
Five hundred grams of dry glycolide are then added to the reactor. The setting for the temperature of the reactor is then increased to 210° C. When the temperature of the reactor reaches 195° C., 2750 grams of glycolide are added with continued stirring. The polymerization is continued for about 25 minutes at 210° C.
The reaction product is isolated, comminuted, and treated to remove residual reactants using known techniques. The copolymer is then heated under vacuum to remove residual water, residual solvent, and/or unreacted monomer.
EXAMPLE 2
1,3 dioxane-2-one (1249 grams) and caprolactone (751 grams) are added to a reactor along with 1.0 grams of stannous octoate and 1 gram of diethylene glycol. The mixture is heated and placed at 160° C. (with stirring) under a nitrogen atmosphere for 3.5 hours. The capralactone/1,3 dioxane-2-one copolymer is then sampled.
Five hundred grams of dry glycolide are then added to the reactor. The setting for the temperature of the reactor is then increased to 210° C. When the temperature of the reactor reaches 195° C., 2500 grams of glycolide are added with continued stirring. The polymerization is continued for about 20 minutes at 210° C.
The reaction product is isolated comminuted, and treated to remove residual reactants using known techniques. The copolymer is then heated under vacuum to remove residual water, residual solvent and/or unreacted mononer.
Table I below sets forth typical conditions for extruding, stretching monofilament sutures in accordance with this invention. All of the monofilament sutures were fabricated from the resin of Example 1 and Example 2.
TABLE I______________________________________CONDITIONS OFMANUFACTURING OF MONOFILAMENTSUTURES OF THE PRESENT INVENTION ExampleProcess Conditions 1 2______________________________________ Extrusion Operationextruder screw, rpm 1.5 2.4pump, rpm 6.9 15.4barrel temp., °C., zone A 200 195barrel temp., °C., zone B 222 220barrel temp., °C., zone C 223 223clamp temp., °C., 223 225adapter temp., °C. 226 225pump temp., °C. 224 225block temp., °C. 224 225barrel melt temp., °C. 218 219pump melt temp., °C. 217 220spinneret melt temp., °C. 217 218barrel pressure, psi 790 800pump pressure, psi 500 500spinneret pressure, psi 1050 500pump size, cc per revolution 0.297 0.160diameter of spinneret, orifices, mm 1.25 1.25no. of spinneret orifices 1 1quench bath temp., °C. 18 18Stretching (Orienting) Operationdraw oven temp., °C. 75 43first godet, mpm 4.6 6.9second godet, mpm 23.2 33.8second oven temp, °C. 100 52third godet, mpm 28.8 36.6draw ratio 6.3:1 5.3:1Freezing Operationtemp., °C. -13 -13time (hrs.) 18 18Annealing Operationoven temp., °C. 97 85time (hrs.) 18 18shrinkage (%) 10 10______________________________________
The physical properties of the sutures and the procedures employed for their measurement are set forth in Table II as follows:
TABLE II______________________________________PROCEDURES FOR MEASURING PHYSICALPROPERTIES OF MONOFILAMENT SUTURESOF THE PRESENT INVENTIONPhysical Property Test Procedure______________________________________knot-pull strength, kg U.S.P. XXI, tensile strength, sutures (881)straight-pull strength, kg ASTM D2256-88, Instron Corporationelongation, % ASTM D2256-88tensile strength, kg/mm.sup.2 ASTM D2256-88, Instron Corporation Series IX Automated Materials Testing System 1.03A______________________________________
Table III below sets forth the physical properties of the suture of the present invention.
TABLE III______________________________________Physical Property Example 1 Example 2______________________________________diameter (mm) 0.301 0.304knot-pull strength (kg) 2.3 2.0Straight-pull strength (kg) 2.8 2.5Elongation (%) 21 21Tensile Strength (kg/mm.sup.2) 39 33______________________________________
As the data in Table III illustrates, the suture made of the copolymer of the present invention showed acceptable physical properties, such as knot pull and straight-pull strength.
Obviously, other modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that changes may be made in particular embodiments of the invention described which are within the full intended scope of the invention as described by the claims. | Block copolymers wherein one of the blocks is made from hard phase forming monomers and another of the blocks is made from soft phase forming monomers copolymerized with randomly intermingled units of other soft phase forming monomers. The copolymers are useful in forming surgical articles, including both monofilament and multifilament sutures. | 2 |
[0001] One significant growth area in the pharmaceutical industry is the increasing prevalence of protein based drug formulations in lyophilized and parental form. As proteins have a strong affinity for the surface of native pharmaceutical packaging materials (e.g., glass and polymers), this results in the loss of product by interaction of the protein to the surface leading to permanent immobilization and/or denaturation. For higher concentration protein based drugs like insulin the accepted solutions to reduce protein adsorption are 1) to compensate for the protein loss by overfilling—using a higher than needed concentration and/or volume to provide enough product to passivate the surface and still maintain the required dosage, 2) to include additives such as sacrificial proteins and/or surfactants in the drug formulation to reduce adsorption, and 3) siliconization of the packaging material (S. M. Shaw, M. J. C. Crabbe Biochem J. 1994, 304,121-129). The addition of proteins from non-recombinant sources generates concern with the possibility of protein bound diseases such as Creutzfeld-Jakob (M. M. Robinson et al Dev. Bio. Stand. 1996, 88, 237-241). With the advent of more specialized (expensive) protein based drugs, the increased costs to overfill the packaging container are undesirable both to the manufacturer and consumer. For example, a higher concentration drug protein such as Humulin N™ (recombinantly produced insulin made by Eli Lily) is used at a 300-400 μg/mL concentration with 10 mL/dose at a cost of $25.00 (pricing Feb. 6, 2006 at www.GetCanadianDrugs.com) while a lower concentration drug protein such as Avonex™ (recombinantly produced interferonαiβ made by Biogen) is used at a 60 μg/mL concentration with a 0.5 mL/dose at a cost of $350.00; pricing Feb. 6, 2006 at www.GetCanadianDrugscom). Starting with a conservative estimate of 5% protein adsorption one would have the potential to decrease the cost by $1.25 and $17.50/dose for Humulin™ and Avonex™, respectively, if one could provide a coating that minimizes protein loss.
[0002] The adsorption of proteins to a surface depends on a variety of factors: substrate surface chemistry (functional groups present on a native surface or coating thereon), surface conditions, such as roughness, the structure of the protein (molecular weight, distribution of amino acids, isoelectric point), and the excipients (binders, disintegrants, diluents, suspension and dispersing agents) present in the protein formulations. The chemically heterogeneous structure of proteins allows for surface interaction through hydrogen bonding and a variety of interaction mechanisms (ionic, hydrophobic, Van der Waals interactions, entanglement, etc.). To mitigate binding through these mechanisms most protein drug formulators rely on various excipients such as carbohydrates (e.g., trehalose, sucrose), buffers systems (e.g., phosphate, tris, citrate) and surfactants (e.g., polysorbate-80 or polysorbate-20). Though these approaches may be well established they are not always possible for different proteins whose activities may be modified by the addition of excipients resulting in the need for each formulation to be tested for stability of the protein drug contained in the package and the effect of the protein adsorption quantified in terms of loss of protein and protein activity.
[0003] Another approach to deter proteins binding to the surface of the package is the application of coatings to the package surface, provided it is feasible in a pharmaceutical packaging scenario (low cost, sterilizable by one or more of the accepted methods of autoclaving/EtO exposure/gamma irradiation/electron beam irradiation, non-toxic, 2-3 year stability, 100% coating deposition verifiable, etc.). A large body of literature has established a set of generally accepted theoretical parameters (Ostuni E., Chapman R. G., Holmin R. E., Takayama S., Whitesides G. M. Langmuir 2001,17,5605-5620) that determine if a surface is likely to deter protein adsorption. In general, a surface that is non-ionic, hydrophilic and hydrogen bond accepting is considered an ideal surface to repel protein adsorption at the liquid/solid interface. The coating should also be sterically hindering to the proteins interaction with the pharmaceutical package and/or component(s) surface (glass, polymer, copolymer, metal, alloys) to avoid not only adsorption, but also denaturation. Other theories have been proposed in the literature to explain the ability of certain coatings to reduce protein adsorption—for instance, see Gombotz et al (Gombotz W. R., Wang G. H., Horbett T A., Hoffmann A. S. J. Biomed. Mater. Res. 1991, 12, 1547-1562), who postulate that the effectiveness of a coating (in this case polyethylene oxide) to structure water at the coating/water interface region influences the ability of a coating to reduce protein adsorption.
[0004] There is a wealth of general knowledge regarding surfaces and or coatings that resist protein adsorption. A non-exhaustive list include polyethylene oxide/glycol-like and other coatings deposited via plasma assisted chemical vapor deposition that deter protein adsorption—see, for example, Erika E. Johnston E. E., Bryers J. D., Ratner B. D. Langmuir 2005, 21, 870-881; Sardella E., Gristina R., Senesi G. S., d'Agostino R., Favia P. Plasma Process. Polym. 2004, 1, 63-72; Shen M., Martinson L., Wagner M. S., Castner D. G., Ratner B. D., Horbett T. A. J. Biomater. Sci. Polymer Edn. 2002,13,367-390; Shen M., Pan Y. V., Wagner M. S., Hauch K. D., Castner D. G., Ratner B. D., Horbett T. A. J. Biomater. Sci. Polymer Edn. 2001, 12,961-978; U.S. Pat. No. 5,153,072; Lopez G. P., Ratner B. D. J. Polym. Sci. A—Polym. Chem. 1992, 30, 2415-2425; and U.S. Pat. No. 5,002,794. For (derivatized) alkanethiol coatings deposited that deter protein adsorption see, for example, Li L. Y., Chen S. F., Ratner B. D., Jiang S. Y. J. Phys. Chem. B 2005, 104, 2934-2941; Chirakul P., Pérez-Luna V. H., Owen H., López G. P. Langmuir 2002, 18, 4324-4330; Prime K. L., Whitesides G. M. J. Am. Chem. Soc. 1993, 115, 10714-10721; Pale-Grosdemange C., Simon F. S., Prime K. L., Whitesides G. M. J. Am. Chem. Soc. 1991, 113, 12-20. For organosilane coatings that deter protein adsorption see, for example, Seigers C., Biesalski M., Haag R. Chem. Eur. J. 2004, 10, 2831-2838; US 2003/0092879; Yang Z., Galloway J. A., Yu H. Langmuir 1999, 15, 8405-8411; Lee S. W., Laibinis P. E. Biomaterials 1998,19,1660-1675; and U.S. Pat. No. 6,235,340. For hydrogel coatings that deter protein adsorption see, for example, U.S. Pat. No. 6,844,028. For poly-L-lysine/polyethylene glycol coatings that deter protein adsorption see, for example, US 2002/0128234; Huang N. P., Michel R., Voros J., Textor M., Hofer R., Rossi A., Elbert D. L., Hubbell J. A., Spencer N. D. Langmuir 2001, 17, 489-498; Kenausis G. L. Vörös J., Elbert D. L., Huang N., Hofer R., Ruiz-Taylor L., Textor M., Hubbell J. A., Spencer N. D. J. Phys. Chem. B 2000, 104,3298-3309. For polyethylene oxide graft coatings see, for example, Sofia S. J., Premnath. V., Merrill E. W. Macromolecules 1998, 31, 5059-5070. These examples represent but are not an exhaustive compilation of the large number of available surface treatment and/or coating possibilities.
[0005] Currently, no commercially available pharmaceutical package (native or coated) contains all of the favorable protein deterring characteristics described above, but tends to have a few desirable ones while still having some that promote protein adsorption. While glass (borosilicate, soda-lime, etc.) is hydrophilic and hydrogen bond accepting, it is highly ionic and has no steric hindrance to deter protein binding. The high density of negative charges under liquid formulation conditions (pH 5-9) on the surface will promote the ionic binding of positively charged residues on the proteins (i.e. lysine, histidine, and the amino terminus). The siliconization of glass to passivate the surface and provide lubricity in syringes results in a relatively non-ionic surface that is sterically blocked, but the silicone oil renders the surface very hydrophobic while decreasing its hydrogen bond accepting ability. Silicone oil treatment can also result in the generation of unwanted particulate matter in syringes as silicone droplets leave the surface and enter the solution. Hydrophobic surfaces tend to exclude water and facilitate the adsorption of proteins. The hydrophobicity of the environment the proteins encounter can also lead to protein denaturation as the hydrophobic core of the proteins seeks to interact with the surface and unfold it's native structure to obtain a minimum free energy conformation. Hydrophobic coatings containing fluorine with anti-adherency properties for solutions/suspensions containing medicinally relevant particles/agglomerates have been prepared previously by plasma enhanced chemical vapor deposition—see, for example, U.S. Pat. No. 6,599,594.
[0006] For drugs delivered in liquid form, lubrication of the delivery system (i.e. syringe) is an important function of the packaging system. The lubricated syringe format is the format most likely to be utilized for high cost protein-based drugs. The currently accepted method of lubrication uses various formulations of silicones to provide lubrication of the syringe barrel as it moves down the syringe body. This method of lubrication, however, suffers from the “stick-slip” problem. It is difficult to accurately dispense from siliconized syringes, as there is a breakaway force that the user needs to apply to overcome the initial sticking forces between the barrel and body and also a sliding force that the user needs to maintain while dispensing. If the user stops before dispensing the entire volume of solution or makes multiple dispensings from the same syringe the user again needs to overcome the breakaway force. Without being restricted by theory, it is believed that the origin of the breakaway force is caused by migration of the lubricant (silicone) away from the contact points between sliding surfaces due to the compression force of the plunger and syringe body. Efforts have been made to reduce and/or eliminate the stick-slip problem. For example U.S. Pat. No. 6,645,635 discloses a tetrafluoroethylene barrier coating for use with stoppers while U.S. Pat. No. 6,582,823 discloses the use of perfluoropolyethers compounds as a wear-resistant coating that could be used as a silicone-free lubricant.
[0007] The stability of a drug formulation prior to delivery can be affected by many factors—the major factors are formulation dependent and packaging dependent. The primary factor affecting drug stability is the interaction of the drug formulation with leachables/extractables or permeating gas species during storage. During storage, glass, polymer, elastomer, and metal packaging components may release species (e.g. Na + , K + , Al 3 + , SiOH n− 4-n , stearic acid, calcium stearate, 2,6-di-tert-butyl-4-methylphenol) that interact with various components of the drug formulation or allow the permeation of gaseous species such as oxygen or carbon dioxide. For example, when storing water for injection in Type 1 glass alkali ion exchange causes the pH to change. Barrier coatings, such as SiO 2 , to reduce the exposure of drug solutions or components thereof to ion exchange and/or various gases, have been produced via plasma enhanced chemical vapor deposition methods to minimize the release of glass constituents into drug formulations. See for example, DE 196 29 877 M. Walther et al.; EP 08 210 79 M Walther et al.; DE 44 38 359 M. Walther et al.; EP 07 094 85 M. Walther et al. and DE 296 09 958 M. Walther et al.
[0008] With the increasing number of biotherapeutic drugs reaching the market and in development (recombinant therapeutic proteins Datamonitor 2004, DMHC 1975) there exists a need for multi-functional pharmaceutical packaging surfaces that incorporate multiple beneficial functions to enhance drug stability (i.e., multi-functional), especially for sensitive protein-solution based drugs. Currently there are no pharmaceutical packaging components that provide a combination of minimized protein loss, lubrication, and barrier properties for the storage and delivery of drug formulations. It is the goal of this invention to provide two or more multiple beneficial functions for pharmaceutical packaging components by the sequential application of two or more coatings.
[0009] Although the primary purpose of this patent application is to provide a packaging solution for protein-based drugs that are packaged in a liquid formulation, the technology described herein can also be applied to other biopharmaceuticals such as nucleic acids, small molecules, polynucleotides (e.g., DNA, RNA, pDNA, etc., oligonucleotides), protein/nucleic acid complexes (e.g., viral particles for gene therapy) that are either in a liquid (“solution”) or solid state (“lyophilized”) format, etc. by straightforward extension.
SUMMARY OF THE INVENTION
[0010] The present invention relates to a multifunctional pharmaceutical package (or synonymously, a pharmaceutical container) having a surface coated with a lubricious coating and a coating that minimizes protein loss (i.e., protein deterrent coating). Preferred lubricious coatings include, for example, silicone oil or a fluorinated polymer lubricant coating. Preferred coatings that minimize protein loss include, for example, a hydrogel coating or a polyether coating. The multi-functional pharmaceutical package surface may also include, for example, a barrier layer coating. The functional coatings may be deposited onto the pharmaceutical package surface by methods conventionally known in the art such as, for example, methods taught in H. K. Pulker Coatings on Glass 2 nd Ed. 1999 Elsevier, Amsterdam-hereby incorporated by reference. Preferred methods are spray coating, dip coating, chemical vapor deposition, plasma assisted chemical vapor deposition, sputtering, ion plating, and evaporation. Each coating may be applied by the same method or by different methods. Any pharmaceutical package that comes in contact with a pharmaceutical or biotechnological substance or formulation can be multi-functionally coated. Preferred pharmaceutical package surfaces which may be multi-functionally coated include vials, plastic-coated vials, syringes, plastic coated syringes, ampoules, plastic coated ampoules, cartridges, bottles, plastic coated bottles, pouches, pumps, sprayers, stoppers, needles, plungers, caps, stents, catheters and implants, and additional components thereof. Additional coatings, which provide functional benefits, include optical coatings that provide transparency or opacity, coating which provide strength, adhesion coatings, break resistant coatings and/or barrier coatings such as, for example, SiO 2 . Pharmaceutical packaging substrates made from glass (e.g., Type 1, a silicate, a borate, a borosilicate, a phosphate, a soda-lime silicate, Type 2, Type 3, and colored versions thereof to protect formulations from various forms of electromagnetic radiation), acrylic, polycarbonate, polyester, polypropylene, polyacetal, polystyrene, polyamide, polyacrylamide, polyimide, polyolefin, cyclic olefin copolymers (e.g. Topas™-COC), rubber, elastomers, thermosetting polymers, thermoplastic polymers, metals, or alloys are contemplated. In particular, pharmaceutical packaging materials that have a siliconized or silanized surface are contemplated.
[0011] In comparison to uncoated pharmaceutical package substrates the protein deterrent-coated substrates of the invention reduce the adsorption of protein to the surface by more than about 25%. Preferred coatings reduce the adsorption of proteins to the surface by more than about 50% and particularly preferred coatings that minimize protein loss reduce the adsorption of proteins to the surface by more than about 75%. Although written in terms of proteins, other macromolecules that are deterred include naturally occurring or synthetically prepared biomolecules or a derivative thereof (e.g., nucleic acid, polynucleotide, protein, carbohydrate, or protein/nucleic acid complex) in solution or solid state.
[0012] Polyethers, such as, diglyme, triglyme, tetraglyme, pentaglyme, hexaglyme, or functionalized derivatives thereof are particularly suitable coatings that minimize protein loss, as are hydrogels. Particularly preferred polyethers are disclosed in U.S. Pat. No. 5,153,072 and U.S. Pat. No. 5,002,794, which are incorporated by reference. Other suitable coatings that minimize protein loss and coating precursors are the compounds disclosed in DE 196 29 877; EP 08 210 79; DE 44 38 359; UP 07 094 85 and DE 296 09 958, all of which are incorporated by reference.
[0013] Hydrogel coatings are also preferred coatings that minimize protein loss (i.e., protein deterrent). Particularly preferred hydrogels are disclosed in U.S. Pat. No. 6,844,028 and US 2005/0100675, which are incorporated by reference. These hydrogel formulations are typically composed of a mixture of solvent, a matrix forming component, a crosslinking component, and an active component made up of a binding group, a spacer group, and a functional group such as, for example, alkoxide (—OR where R is an alkyl group) or a secondary amine.
[0014] Lubricious coatings that are particularly suitable include silicone oils such as those taught in U.S. Pat. No. 5,736,251, U.S. Pat. Nos. 5,338,312, and 6,461,334, all of which are incorporated by reference. Also preferred are hydrophobic coatings containing fluorine such as those taught in U.S. Pat. No. 6,599,594, which is hereby incorporated by reference. Particularly suitable fluorinated polymer lubricious coatings include perfluorinated polyethers or fluorinated hydrocarbons. In comparison to uncoated pharmaceutical package substrates the coated substrates of the invention increase the lubricity of the surface by more than about 25%. Preferred lubricious coatings increase the lubricity of the surface by more than about 50% and particularly preferred lubricious coatings increase the lubricity of the surface by more than about 75%. Preferably, the lubricious coating does not detract from the protein deterrent functions of the coating that minimizes protein loss.
[0015] Particularly suitable barrier coatings which reduce the exposure of drug solutions or components thereof to ion exchange and/or various gases include, for example, those disclosed in DE 196 29 877 M. Walther et al.; EP 08 210 79 M Walther et al.; DE 44 38 359 M. Walther et al.; EP 07 094 85 M. Walther et al. and DE 296 09 958 M. Walther et al, all of which are incorporated by reference.
[0016] Suitable coatings may be deposited in sequence. Preferably, the coating that minimizes protein loss may be applied over an existing coating such as a lubricious coating, a barrier layer (e.g., SiO 2 , TiO 2 , ZrO 2 or Al 2 O 3 ), an adhesion layer, or an optical layer. Alternatively, the preferred coating that minimizes protein loss may be applied under a coating such as a lubricious coating, a barrier layer (e.g., SiO 2 , TiO 2 , ZrO 2 or Al 2 O 3 ), an adhesion layer, or an optical layer.
[0017] The invention also relates to methods of preparing a multi-functional pharmaceutical package surface coated with a lubricious coating and a coating that minimizes protein loss (i.e. protein deterrent coating) and optionally a barrier coating, an adhesion layer, an optical coating and/or a strength coating
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0018] Various features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
[0019] FIG. 1 : Protein adsorption of fluorescently labeled insulin and histone results for syringes coated with a lubricious coating and a coating that minimizes protein loss.
[0020] FIG. 2 : Protein adsorption of fluorescently labeled insulin, histone, IgG, and lysozyme results for syringes coated with a lubricious coating and a coating that minimizes protein loss.
[0021] FIG. 3 : Breakaway and sliding force comparison of syringes with a silicone oil coating vs. syringes with silicone oil and a coating that minimizes protein loss.
DETAILED DESCRIPTION OF THE INVENTION
[0022] As used herein, protein solution refers to a particular protein of interest in the presence of (typically) an aqueous solution that may contain various additives, which can also have an effect on the adsorption of the proteins to the surface. Typical protein solutions to be tested contain pharmaceutically relevant moieties such as cells, tissues, and derivatives thereof. Among the proteins are included any polyaminoacid chain, peptides, protein fragments and different types of proteins (e.g., structural, membrane, enzymes, antigens, monoclonal antibodies; polyclonal antibodies, ligands, receptors) produced naturally or recombinantly, as well as the derivatives of these compounds, etc. Specific protein drugs include antibodies (e.g. Remicade and ReoPro from Centocor; Herceptin from Genentech; Mylotarg from Wyeth, Synagis from MedImmune), enzymes (e.g. Pulmozyme from Genentech; Cerezyme from Genzyme), recombinant hormones (e.g., Protropin from Genentech, Novolin from Zymogenetics, Humulin from Lilly), recombinant interferon (e.g., Actimmune from InterMune Pharmaceutical; Avonex from BiogenIdec, Betaseron from Chiron; Infergen from Amgen; Intron A from Schering-Plough; Roferon from Hoffman-La Roche), recombinant blood clotting cascade factors (e.g., TNKase from Genentech; Retavase from Centocor; Refacto from Genetics Institute; Kogenate from Bayer) and recombinant erythropoietin (e.g., Epogen from Amgen; Procrit from J&J), and vaccines (e.g., Engerix-B from GSK; Recombivax HB from Merck & Co.).
[0023] The term “multi-functional” refers to two or more beneficial desirable properties provided by coatings for pharmaceutical packaging used for the storage and delivery of drug formulations. These include, but are not limited to, coatings which minimize protein adsorption (i.e., protein deterrent coating), provide lubrication, provide a barrier to leachables, extractables, and permeating gases, provide optical transparency, provide optical opacity, provide break resistance and are compatible with sterilization methods.
[0024] The term “pharmaceutical package” as used herein means any container or medical device or component(s) thereof that comes in contact with a pharmaceutical, biological or biotechnological substance or formulation in solution or solid state. Examples include vials, plastic-coated vials, syringes, plastic coated syringes, ampoules, plastic coated ampoules, cartridges, bottles, plastic coated bottles, pouches, pumps, sprayers, stoppers, needles, plungers, caps, catheters, stents, implants, and components thereof which come in contact with proteins.
[0025] With regards to the coatings that minimize protein loss, the coating precursors may be from any chemical family. Preferably, the coating will be universal, and as such deter the adsorption of all potential protein formulations. In some instances, this will not be the case and an initial analysis of some of the proteins properties (e.g., pI, charged residues, modifications such as glycosilations, hydrophobicity and/or hydrophilicity) could lead to specific modifications to be included in the coating formulation. Analysis of the surface (e.g., energy, roughness, charge, and functional groups) of various packaging components could also lead to specific characteristics and/or modifications of the coating formulation to reduce the adsorption of the protein. With this in mind, preferred coating families are glycols, ethers, esters, alcohols, methacrylates, silanes and derivatized members thereof. Especially preferred coating precursors for use in the present invention include compounds containing the elements C, H and O; polyethylene glycols, glycol ethers, commonly known as glymes (e.g., monoglyme, ethyl glyme, diglyme, ethyl diglyme, triglyme, butyl diglyme, tetraglyme, pentaglyme, hexaglyme and their respective corresponding monoalkyl ethers) and functionalized derivatizes such as, for example, polyethylene glycol with an end functionalized silane. The coating thickness can range from a monolayer to 1000 nm. Preferably the protein deterrent coating is from about 1 to 1000 nm, most preferably the protein deterrent coating is from about 1 to 500 nm and coatings of about 1 to 250 nm are most preferred.
[0026] Hydrogel coatings are another class of particularly preferred coating that minimizes protein loss. Preferred hydrogels and methods of applying the hydrogels to surfaces are disclosed in U.S. Pat. No. 6,844,028, US 2004-0115721 and US 2005-0100675, which are all incorporated by reference. These hydrogel formulations are typically composed of a mixture of solvent(s), a matrix forming component, a crosslinking component, and an active component, the active component consisting of a binding group, a spacer group, and a functional group. Particularly preferred hydrogels comprise a NH 2 -PEG-silane or methoxy-PEG-silane active component.
[0027] The coatings that minimize protein loss (e.g., hydrogel or polyether) may be deposited over other functional coatings such as, for example, a barrier coating (e.g., an oxides such as SiO 2 ) or a lubricious coating. Alternatively, the coating that minimizes protein loss (e.g., hydrogel or polyether) may be deposited under other functional coatings such as a barrier coatings or a lubricious coating.
[0028] There are numerous types of known lubricants, such as non-siliconized oils (i.e. vegetable oils), fats, waxes, and hydrophilic polymers such as those disclosed in U.S. Pat. No. 6,723,350. With regards to the lubricious coating, a preferred lubricant coating to provide the pharmaceutical package with lubricious surface quality is silicone oil (“silicone”). Silicones are inorganic polymers containing a silicon-oxygen backbone with side chains or groups attached to the silicon atoms. Silicones are also called polysiloxanes. One of the most commonly encountered polysiloxanes is polydimethylsiloxane (“PDMS”). Silicone properties can be varied extensively by modification of side chains, end group modification, backbone chain length, backbone and crosslinking of two or more polysiloxane monomers during polysiloxane synthesis. Taking trimethylsiloxane endcapped polydimethylsiloxane as a basic model polysiloxane,
[0000]
[0029] there are numerous modifications which can be made during polysiloxane synthesis using different siloxane monomers resulting in a silicone oil with desirable lubricant properties (e.g., viscosity, reactivity, hydrophobicity, etc.): side chain modification involves replacement of one or more methyl groups (—CH 3 ) with various functional groups such as —H, —CH═Cl 2 , —OCH 3 , —CH 2 CH 2 CF 3 ; endgroup modification involves replacement of one or more methyl groups with various reactive groups such as —OH, —CH═CH 2 , —OC(CH 2 )CH 3 , —OCH 3 , etc. for crosslinking purposes. A more comprehensive but non-exhaustive listing of siloxane monomers/polymers and a chemical discussion of polysiloxane chemistry can be found in Silicon Compounds: Silanes & Silicones Ed. Barry Arkles, Gerald Larson 2004, Gelest Inc. and Silicones in Pharmaceutical Applications André Colas, 2001, Dow Coming Healthcare Industries.
[0030] One special consideration for lubricants used in pharmaceutical packaging is the need for high chemical purity and low reactivity. In certain embodiments, this limits the type of polysiloxane that can be used due to purity that can be obtained due to the separation of desired lubricant from synthesis by-products. Another consideration is the desired properties of the lubricant (viscosity, crosslinking ability, lubricity, deposition neat or diluted, solubility in specific diluting solvents, etc.) the type of sterilization (e.g., steam sterilization such as autoclave, gamma irradiation, ethylene oxide sterilization and heat sterilization such as depyrogenation) it will undergo, and the type of surface to which it will be applied (e.g., glass, polymeric, metal; syringe bodies, syringe plungers, stoppers, needles, etc.). For pharmaceutical packaging use, polysiloxanes are sold under USP or medical grade purities. There are two types of polysiloxane formulations used for pharmaceutical packaging, those that have the lubricant already formed and those that form the lubricant prior to application. Examples of silicone oils and silicone oils with additives ready to apply with/without dilution to glass and polymeric surfaces would be Dow Corning 360 and Dow Corning 365 35% dimethicone NF emulsion. An example of a silicone oil ready to apply with/without dilution to metallic surfaces would be Dow Corning MDX4-4159 medical grade dispersion. Examples of polysiloxane formulations that form the lubricant prior to application are multiple component formulations. The most common types of formulations are to provide two (poly)siloxane components and crosslink them to provide a polysiloxane with the desired properties. Crosslinking can be accomplished via many types of curing reactions. The predominant crosslinking reactions employ platinum catalysts or peroxides for initiation. Physical methods are also used to enhance crosslinking such as exposure to electromagnetic radiation (ultraviolet—gamma rays) and heating. Vinyl end-capped siloxanes and hydrosiloxanes combined with a platinum catalyst are preferred species due to the purity of polysiloxane produced (only by-product is residual platinum in the part per million concentration level).
[0031] In a preferred embodiment of the invention the silicone oil lubricant that is used is made from the combination of multiple reactive polysiloxanes with a non-reactive polysiloxane as disclosed in U.S. Pat. No. 6,296,893. Other suitable silicone oils, preferred methods of application, and uses in pharmaceutical packaging are taught in U.S. Pat. No. 5,736,251, U.S. Pat. Nos. 5,338,312 and 6,461,334, which are herein incorporated by reference. U.S. Pat. No. 5,736,251 discloses silicone coatings and treatments which upon curing result in a three dimensional lubricant structure effective at reducing by 50-80% the coefficient of friction compared to uncoated surfaces. U.S. Pat. No. 5,338,312 discloses a first silicone crosslinked base layer and second silicone layer providing lubrication to an article. U.S. Pat. No. 6,461,334 discloses a silicon containing coating that is both lubricious and protein deterrent. U.S. Pat. Nos. 6,866,656, 6,461,334, U.S. Pat. No. 5,338,312, U.S. Pat. No. 5,736,251, U.S. Pat. No. 5,338,312, U.S. Pat. No. 6,461,334, U.S. Pat. No. 6,296,893, U.S. Pat. No. 4,822,632, WO 88/10130, Silanes & Silicones Ed. Barry Arkles, Gerald Larson 2004, Gelest Inc. and Silicones in Pharmaceutical Applications Andre Colas, 2001, are all incorporated by reference.
[0032] Fluorinated polymer compounds are another preferred class of suitable lubricants that can be used for the lubricous coating of the pharmaceutical packaging surface. Preferred lubricious compounds are, for example, the perfluorinated polyethers or fluorinated hydrocarbons disclosed in US Application 2004/0231926 and the lubricants disclosed in U.S. Pat. No. 6,645,483, both of which are hereby incorporated by reference.
[0033] In certain embodiments the lubricious coating (e.g., silicone or fluorinated polymer) is deposited over a functional coating such as a barrier coating (e.g., oxides such as SiO 2 ) or a coating that minimizes protein loss. Alternatively, the lubricious coating may be deposited under other functional coatings such as a barrier coatings (e.g., oxides such as SiO 2 ) or a coating that minimizes protein loss. The lubricious coating thickness can range from a monolayer to about 1000 nm. Preferably the lubricious coating is from about 1 to 700 nm; most preferably the lubricious coating is from about 1 to 500 nm.
[0034] There are many types of barrier coatings, which may be applied to pharmaceutical packaging surfaces that have the ability to retard, to varying extents, the permeation of gaseous species such as water vapor and carbon dioxide. These coating thereby provide protection to the substances stored within. Barrier coatings may also be applied to pharmaceutical packaging surface to retard, to varying extent, the leaching of components from the base substrate and/or the ion exchange of cations/anions with the base substrate. Preferred barrier coatings and methods of applying the barrier coatings are disclosed in DE 196 29 877, EP 08 210 79, DE 44 38 359, EP 07 094 85, and DE 296 09 958, and in US 2003/0134060, US 2004/0247948, US 2005/0227002, all hereby incorporated by reference. In certain embodiments the barrier coating (e.g., oxides such as SiO 2 ) is deposited over a coating that minimizes protein loss. Alternatively, the barrier coating (e.g., oxides such as SiO 2 ) is deposited under a coating that minimizes protein loss. Particularly preferred barrier coatings are those coatings that do not interfere with the protein deterrent functions of the coating that minimizes protein loss.
[0035] Preferred embodiments of this invention use a barrier coating with a coating that minimizes protein loss and a barrier coating with a coating that minimizes protein loss and a lubricious coating. In certain embodiments of the present invention, the barrier coating (e.g., oxides such as SiO 2 ) is deposited over another functional coating such as the lubricious coating or over the coating that minimizes protein loss. Alternatively, a barrier coating (e.g., oxides such as SiO 2 ) may be deposited under a coating such as the lubricous coating or the coating that minimizes protein loss. The barrier coating thickness can range from a monolayer to about 500 nm. Preferably the barrier coating is from about 5 to 500 nm; most preferably the lubricious coating is from about 10 to 300 nm. Barrier coatings of 5-200 nm are most preferred such as, for example, about a 100 nm barrier coating.
[0036] The various multi-functional coatings adhere to each other by a variety of mechanisms depending on the chosen coating. Without being bound by theory, the various coatings adhere by adsorption, physical entanglement, hydrogen bonding, covalent bonding, and electrostatic interaction.
[0037] Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. The entire disclosure[s] of all patent applications, patents, and papers cited herein are incorporated by reference herein.
EXAMPLES
[0038] 1) Lubricious coating plus coating that minimizes protein loss.
[0039] A matrix of proteins and formulations is tested to establish the adsorption of proteins to various coated surfaces. These tests are conducted in syringes (Type 1 glass and COC polymer materials) by the methods disclosed in U.S. Application 60/617,192 titled “Multiplexed protein adsorption assay” where a coated surface can be exposed to multiple proteins under different conditions simultaneously. U.S. application 60/617,192 is incorporated by reference.
[0040] Fluorescently labeled (Cy-3 dye from Amersham) insulin and histone are used as two test proteins which are brought into contact with the interior surfaces of syringes in liquid formulations to investigate if protein deterrence could be accomplished, while at the same time maintaining lubricity. The interior surfaces of the syringes are sequentially coated by a coating that minimizes protein loss followed by a silicone oil coating. The protein deterrent hydrogel coating is taught in the examples of US 2004-0115721 and the compound is further modified by blocking. The lubricious silicone oil coating used in this example is taught in U.S. Pat. No. 6,296,893.
[0041] Six different coated articles are prepared: 1) TNS refers to Topas™ not siliconized, 2) TS refers to Topas™ siliconized, 3) TH refers to Topas™ with a hydrogel coating that minimizes protein loss, 4) THS refers to Topas™ with a hydrogel coating that minimizes protein loss followed by silicon oil coating, 5) GH refers to Type 1 glass with a hydrogel coating that minimizes protein loss, and 6) GHS refers to Type 1 glass with a hydrogel coating that minimizes protein loss followed by silicon oil coating. The results shown in FIG. 1 demonstrate that the protein deterrence exhibited by a hydrogel coating on Topas™ as well as Type I glass is maintained, even after a silicone oil coating is secondarily deposited for lubricity. This is a surprising result showing that the protein deterring ability of the protein deterring coating is maintained with the addition of a second coating to provide lubricity.
[0042] 2) Lubricious coating plus coating that minimizes protein loss.
[0043] Example 1 is repeated with the addition of fluorescently labeled IgG and lysozyme to test a broader range of proteins. The results shown in FIG. 2 are similar to those shown in Example 1 which demonstrated that the protein deterrence exhibited by a hydrogel coating on Topas™ as well as Type 1 glass are maintained, even after a silicone oil coating is secondarily deposited for lubricity.
[0044] 3) Lubricious coating plus coating that minimizes protein loss.
[0045] Syringes with a silicone oil coating are spray-coated with the hydrogel coating that minimizes protein loss used in Examples 1 and 2. Frictional force measurements are conducted using an Instron 5564 to determine the breakaway/sliding force profile of syringes with silicone oil coating compared to syringes with silicone oil coating plus coating that minimizes protein loss. The results shown in FIG. 3 demonstrate that the lubricity of both syringe types is statistically similar, as the standard deviation for each average force profile is ±1 newton. This is a surprising result that the lubricant properties of the lubricant coating are maintained with the addition of a protein deterrent coating layer beneath the lubricant coating layer.
[0046] The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples. From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. | The present invention relates to a multi-functional pharmaceutical package surface and a method of preparing a multi-functional pharmaceutical package surface. In particular, the present invention relates to a pharmaceutical package having a protein deterrent and lubricious surface and methods of preparing said surface by applying coatings directly to the pharmaceutical package that (a) reduce the adsorption of proteins onto pharmaceutical packaging while not affecting the activity of the protein solution and (b) provide a lubricious surface. The pharmaceutical package surface may also contain a barrier coating. Coatings can be deposited on a variety of pharmaceutical packaging materials and configurations by various methods. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority, under 35 U.S.C. §119, of Austrian patent application AT A111/2014, filed Feb. 17, 2014; the prior application is herewith incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to an installation for conveying materials, products, and the like, having at least one continuous conveyor belt which is guided via rollers, having a leading belt run for conveying the materials or products, respectively, and having a returning belt run, furthermore having a unit for detecting and controlling the tension of the conveyor belt, and having a unit for detecting deviations of the direction of movement of the conveyor belt from the correct direction of movement and for correcting the direction of movement of the conveyor belt, wherein the unit for detecting and controlling the tension of the conveyor belt displays a pressure-measuring apparatus which is situated at a mounting of a roller, and the unit for detecting deviations of the direction of movement of the at least one conveyor belt from the correct direction of movement and for correcting the deviations furthermore displays a sensor which is assigned to a lateral periphery of the conveyor belt, the output of the sensor, for the correction of the direction of movement of the at least one conveyor belt, serving for adjusting one of the mountings of one roller.
[0003] The present invention, in particular, relates to an installation for producing paper, having at least one wire belt or one felt belt, respectively, which is guided via rollers, in particular drying rollers, for producing a paper web, wherein the wire belt and the felt belt, respectively, represent a conveyor belt.
[0004] In the case of installations of this type for conveying materials, products, and the like, there is the requirement for orderly operation that the at least one conveyor belt exhibits a predetermined tension and that the conveyor belt is moved exactly in the conveying direction.
[0005] In the case of installations for producing paper the quality of the paper being produced is influenced by the tension of the wire belt or the felt belt, respectively. Furthermore, if the wire belt or the felt belt does not run in the correct direction of movement, the belt will move out of the directional path, on account of which the production process is disturbed.
[0006] In order to be able to control the tension of the conveyor belt it is known for one of the rollers via which the conveyor belt is guided to be configured with a pressure-measuring apparatus, in order to thereby detect the tension of the conveyor belt. The conveyor belt is moreover guided via a roller which is adjustable in the direction of movement of the conveyor belt, on account of which the tension of the conveyor belt can be controlled so as to be at the required value.
[0007] In order to be able to control the direction of movement of the conveyor belt it is known for a sensor to be assigned to one of the lateral peripheries of the conveyor belt, on account of which deviations from the required direction of movement of the conveyor belt can be identified. As has been narrated above, one of the two mountings of one of the rollers is configured with a pressure-measuring apparatus. Furthermore, the other mounting of this roller is adjustable in the direction of movement of the conveyor belt. On account of this adjustment of the mounting of one of the rollers in relation to the conveyor belt, which adjustment is controlled so as to emanate from the sensor, the direction of movement of the conveyor belt can be controlled so that the latter moves exactly in the required direction.
[0008] In the case of known installations for conveying materials, products, and the like, on the one hand, one of the mountings of one of the rollers is thus configured having a pressure-measuring apparatus which serves for detecting the tension of the conveyor belt, and, on the other hand, the other mounting of this roller is adjustable in relation to the conveyor belt, in order to thereby be able to control the direction of movement of the conveyor belt.
SUMMARY OF THE INVENTION
[0009] It is accordingly an object of the invention to provide an installation for conveying materials and products with a continuous conveyor belt, which overcomes the above-mentioned and other disadvantages of the heretofore-known devices and methods of this general type and which simplifies the constructive configuration of such a conveying installation.
[0010] With the foregoing and other objects in view there is provided, in accordance with the invention, a conveying installation, comprising:
[0011] at least one endless conveyor belt guided via a plurality of rollers, the conveyor belt having a leading belt run for conveying goods and a returning belt run;
[0012] at least one of the rollers having an adjustable mounting or bearing configured for adjusting and correcting a direction of movement of the at least one conveyor belt;
[0013] a tensioning unit for detecting and controlling a tension of the conveyor belt, the tensioning unit including a pressure-measuring apparatus disposed at the adjustable mounting of the one of the rollers;
[0014] a movement correction unit for detecting deviations of a direction of movement of the conveyor belt from a correct direction of movement and for correcting the direction of movement of the conveyor belt, the unit for detecting movement deviations including a sensor disposed to monitor a lateral periphery of the conveyor belt and having a sensor output configured for adjusting the adjustable mounting of the one of the rollers.
[0015] The installation is particularly configured as a papermaking installation for manufacturing a paper web, wherein the at least one conveyor belt is at least one wire belt or at least one felt belt.
[0016] In other words, the objects of the invention are achieved according to the invention in that the pressure-measuring apparatus for detecting the tension of the conveyor belt is situated at that mounting of one of the rollers that is adjustable for correcting the direction of movement of the at least one conveyor belt. The term mounting, as used herein, is substantially synonymous with the term bearing.
[0017] Since thus both the unit for detecting the tension of the conveyor belt and also the unit for controlling the direction of movement of the conveyor belt are assigned to the same mounting of a roller of the installation, the effect is simplification in the construction, the assembly, the maintenance and in the exchange of component parts. This advantageous effect is obtained in particular when an existing conveying installation is retrofitted, since then the assembly works required therefor have to be performed only on one side of one of the rollers.
[0018] Preferably, the mounting of that roller at which the pressure-measuring apparatus is disposed is situated on a carriage which is adjustable in the direction of movement of the conveyor belt, wherein the pressure-measuring apparatus is disposed between the mounting and the carriage.
[0019] According to one preferred embodiment, the unit for detecting and controlling the tension of the at least one conveyor belt displays a pressure-measuring apparatus, the output of which is guided to a control unit by way of which the tension of the conveyor belt is detected, wherein the output of the control unit serves for adjusting a further roller in the direction of movement of the conveyor belt. The unit for detecting and controlling the tension of the conveyor belt may furthermore display a roller which is wrapped to at least 10° by the conveyor belt and which is adjustable in the direction of movement of the conveyor belt. The carriage on which one of the mountings of the roller is situated is adjustable by means of a correcting unit which is actuatable in a hydraulic or pneumatic manner, respectively, and which is controlled by the unit for detecting deviations of the direction of movement from the correct direction of movement of the conveyor belt.
[0020] According to one further preferred embodiment, that mounting for a roller that is adjustable for correcting the direction of movement of the at least one conveyor belt, in particular adjustable in the direction of movement direction of said conveyor belt, is mechanically coupled for feedback to the sensor for identifying deviations of the direction of movement of the at least one conveyor belt from the correct direction of movement of the conveyor belt. Furthermore, that roller to which the units for detecting and controlling the tension of the conveyor belt and for detecting and correcting the direction of movement of the conveyor belt are assigned is preferably situated in the region of the returning run of the conveyor belt.
[0021] In particular, an installation according to the invention is configured having two continuous conveyor belts, the material to be conveyed being situated between them, wherein each of these two conveyor belts is guided via one roller in which one of the mountings is assigned a unit for detecting and controlling the tension of the conveyor belts, and this mounting furthermore is adjustable in the direction of movement of the assigned conveyor belt.
[0022] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0023] Although the invention is illustrated and described herein as embodied in Installation for conveying materials, products, and the like, having at least one continuous conveyor belt, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0024] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0025] FIG. 1 shows a portion of an installation for producing a paper web, having two continuous felt belts which are movable so as to revolve, the paper web being situated between said felt belts, in a schematic illustration, and
[0026] FIG. 2 shows a roller via which a felt belt is guided, wherein one mounting of this roller is assigned a unit for detecting the tension of the felt belt and a unit for controlling the direction of movement of the felt belt, in an axonometric illustration.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is shown a portion of an installation for producing paper with two groups of rollers 21 , 22 and 21 a , 22 a , respectively, and deflecting rollers 3 and 3 a , respectively, which are assigned to the former, and two continuous felt belts 1 and 1 a , respectively, which are movable so as to revolve. The belts are guided via the rollers 21 a , 22 and 22 a , respectively, and the deflecting rollers 3 and 3 a , respectively. A paper web 4 thereby moved through this portion is situated between the felt belts 1 and 1 a , respectively, and the rollers 22 and 22 a , respectively.
[0028] The rollers 22 and 22 a , respectively, which are heated rollers, represent drying rollers for the paper web 4 . At least some of the rollers 22 and 22 a , respectively, are driven.
[0029] In the left region illustrated in the drawing, the paper web 4 is guided via the roller 21 of the first group of rollers. Consequently, the felt belt 1 bears on the paper web 4 , which felt belt 1 at the same time is guided together with the paper web 4 via the roller 21 a of the second group of rollers, the felt belt 1 being situated between the paper web 4 and the roller 21 a . Thereafter, the felt belt 1 and the paper web 4 reach the first roller 22 of the first group of the rollers, the paper web 4 being situated between the felt belt 1 and this roller 22 . Continuing therefrom, the felt belt 1 is guided via the first deflecting roller 3 of the deflecting rollers assigned to the first rollers to the following roller 22 , whereas the paper web 4 moves via the first roller 22 a of the second group of the rollers which are assigned to the second felt belt 1 a . The second felt belt 1 a is moved via the first deflecting roller 3 a of the deflecting rollers 3 a assigned to the second group of rollers and consequently comes to bear on the paper web 4 which is guided via the first roller 22 a , the paper web 4 being situated between the second felt belt 1 a and the first roller 22 a . Thereafter, the second felt belt 1 a is guided via a further deflecting roller 3 a and a further roller 22 a.
[0030] Continuing therefrom the first felt belt 1 is guided via the further deflecting rollers 3 and the further rollers 22 , and the second felt belt 1 a is guided via the further deflecting rollers 3 a and via the further rollers 22 a.
[0031] The paper web 4 is guided in an alternating manner via a roller 22 of the first group of the rollers and via a roller 22 a of the second group of the rollers 22 a , the paper web 4 in the regions of the rollers 22 and 22 a , respectively, always being situated between one of the two felt belts 1 and 1 a , respectively, and the rollers 22 and 22 a , respectively.
[0032] At the end of this portion of this installation, the felt belts 1 and 1 a , respectively, are guided back to the beginning of this portion via further rollers 31 , 32 , 33 , 34 and 31 a , 32 a , 33 a , respectively, by way of which the felt belts 1 and 1 a , respectively, are deflected.
[0033] In the case of installations for producing a paper web there is, on the one hand, the requirement that the at least one felt belt displays a predetermined tension, since the quality of the produced paper depends on the tension of the felt belt or the felt belts, respectively. It must furthermore be ensured that the felt belt or the felt belts, respectively, moves or move in exactly the correct direction of movement, since a deviation of the felt belt or the felt belts, respectively, from the correct movement path causes functional disruptions in the operation of this installation.
[0034] In order to have the effect of controlling the tension of the at least one felt belt, a unit 5 for detecting and controlling the tension of the felt belt 1 is provided in the region of the returning run of the first felt belt 1 . The unit 5 is also referred to as a tensioning unit. The roller 33 here is assigned a pressure-measuring apparatus 51 by way of which the pressure exerted on the roller 33 by the felt belt 1 is detected. The output signal of the pressure-measuring apparatus 51 is transmitted via a measuring line 52 to a control unit 53 by way of which the tension of the felt belt 1 is detected. The output of the control unit 53 is transmitted via a control line 54 to a correcting unit 55 for the roller 32 , by way of which the roller 32 is displaceable in the direction of movement of the felt belt 1 . The roller 32 is wrapped to 90° by the first felt belt 1 . The wrapping is at least 10° and may also be 180°. On account of this wrapping, the tension of the felt belt 1 can be controlled to be a predetermined value by way of an adjustment of the roller 32 .
[0035] Two end positions of the displaceable roller 32 are illustrated in FIG. 1 .
[0036] Furthermore, a unit 6 for detecting deviations of the first felt belt 1 from the correct movement path and for correcting the direction of movement of the felt belt 6 is provided, which unit 6 includes a sensor 61 , which is assigned to a periphery of the felt belt 1 , and a control unit 62 . The unit 6 is also referred to as a movement correction unit. Deviations in the direction of movement of the felt belt 1 from the correct direction of movement are detected by the sensor 61 . Correction of the direction of movement of the felt belt 1 is performed by way of the control unit 62 . To this end, the roller 33 is configured having a mounting which is displaceable in the direction of movement of the felt belt 1 . By way of an adjustment of this mounting the angular position of the roller 33 in relation to the felt belt 1 is modified, on account of which the direction of movement of the felt belt 1 is controllable.
[0037] In an analogous manner, a unit 5 a (also referred to as a tensioning unit) for detecting and controlling the tension of the felt belt 1 a is assigned to the roller 33 a , via which the returning run of the second felt belt 1 a is guided. Here, one of the two mountings of the roller 33 a is assigned a pressure-measuring apparatus 51 a by way of which the pressure exerted on the roller 33 a by the felt belt 1 a is detected. The output signal of the pressure-measuring apparatus 51 a is transmitted via a measuring line 52 a to a control unit 53 a , by way of which the tension of the felt belt 1 a is detected. The output of the control unit 53 a is guided via a control line 54 a to a correcting unit 55 a , by way of which the roller 32 a which is wrapped by the felt belt 1 a is displaceable in the direction of movement of the felt belt 1 a , on account of which the tension of the felt belt 1 a is controllable.
[0038] Furthermore, a unit 6 a (also referred to as a movement correction unit) for detecting deviations of the second felt belt 1 a from the correct movement path and for correcting the direction of movement of the felt belt 1 a is provided, which unit 6 a displays a sensor 61 a , which is assigned to a periphery of the felt belt 1 a , and a control unit 62 a . Deviations of the direction of movement of the felt belt 1 a from the correct direction of movement are detected by the sensor 61 a . Correction of the direction of movement of the felt belt 1 a is performed by the control unit 62 a . To this end, the roller 33 a is configured having a mounting which is displaceable in the direction of movement of the felt belt 1 a . By way of an adjustment of this mounting the angular position of this roller 33 a in relation to the felt belt 1 a is modified, on account of which the direction of movement of the felt belt 1 a is controllable.
[0039] The functioning of the units for detecting the tension of the two felt belts 1 and 1 a , respectively, for controlling the tension of the felt belts 1 and 1 a , respectively, for detecting deviations of the direction of movement of the felt belts 1 and 1 a , respectively, from the correct direction of movement, and for correcting the directions of movement of the two felt belts 1 and 1 a , respectively, are explained by means of FIG. 1 .
[0040] To this end it is noted here that the felt belts 1 and 1 a represent the conveyor belts for the paper web 4 .
[0041] An embodiment according to the invention of these units will now be explained below with reference to FIG. 2 .
[0042] In FIG. 2 the roller 33 via which the felt belt 1 is guided and of which one of the mountings is configured having the pressure-measuring apparatus 51 is illustrated. The tension of the felt belt 1 is controllable by means of units 5 assigned to this roller 33 . Furthermore, the mounting of this roller 33 is displaceable in the direction of movement of the felt belt 1 , on account of which the direction of movement of the felt belt 1 is controllable.
[0043] The roller 33 , on one of its two ends, is mounted on a bearing mounting 30 which is situated on a carriage 60 which is displaceable in the direction of movement of the felt belt 1 . The pressure-measuring apparatus 51 which is preferably configured as a support-pressure measuring apparatus is situated between the bearing mounting 30 and the carriage 60 . The output of the pressure-measuring apparatus 51 is guided via the control line 52 to the control unit 53 . By way of the pressure-measuring apparatus 51 that pressure which is exerted on the roller 33 by the felt belt 1 is detected. The tension of the felt belt 1 is calculated therefrom by means of the control unit 53 . By way of the output signal of the control unit 53 , which is guided via the control line 54 to the correcting unit 55 , the correcting unit 55 is controlled so that the roller 32 is adjusted in the direction of movement of the felt belt 1 , on account of which the tension of the felt belt 1 is controlled.
[0044] The unit 6 for controlling and correcting the direction of movement of the felt belt 1 is configured having the sensor 61 which is pivotably mounted on a support frame 63 . Since the sensor 61 bears on one of the two lateral peripheries 11 of the felt belt 1 , said sensor 61 is pivoted by a deviation of the felt belt 1 from the correct direction of movement. On account of the sensor 61 being pivoted, a control valve 62 which is situated in a hydraulic or pneumatic control system is activated. Pressure lines 64 which lead to a correcting cylinder 65 having a correcting piston 66 are connected to the control valve 62 . The carriage 60 on which the bearing mounting 30 is situated is adjustable by the correcting piston 66 . By an adjustment of the carriage 60 the bearing mounting 30 is adjusted in the direction of movement of the felt belt 1 , on account of which the angular position of the roller 33 in relation to the direction of movement of the felt belt 1 is modified. By way of this modification of the angular position of the roller 33 the direction of movement of the felt belt 1 is controlled.
[0045] Since the bearing mounting 30 is coupled to the support frame 63 by way of a linkage 67 , a mechanical coupling for feedback of this control pertaining to the position of the sensor 61 is performed.
[0046] The adjustment of the carriage 60 by way of the output signal of the sensor 61 may also be electrically controlled.
[0047] Another correcting unit for the carriage 60 may also be provided in place of the correcting cylinder 65 having the correcting piston 66 .
[0048] The units for detecting and for controlling the tension of the felt belt 1 a and for detecting and controlling the direction of movement of the felt belt 1 a which are assigned to the second felt belt 1 a are configured in the same manner.
[0049] In the case of this constructive design it is relevant that the units for detecting the tension of the felt belts 1 and 1 a , respectively, and for controlling the directions of movement of the felt belts 1 and 1 a , respectively, are assigned to only one of the two mountings of a roller via which the felt belt 1 is guided, on account of which simplifications in erecting, converting, operating, and maintaining the installation can be achieved.
[0050] The present invention has been explained above by means of an installation for producing paper, in which the felt belts represent the conveyor belts for the paper web produced in the installation. However, the invention is also applicable to other installations which display at least one movable and continuous conveyor belt for transporting or for processing, respectively, materials or goods, respectively, since in the case of installations of this type controls for the tensions of the conveyor belts and for monitoring and correcting the directions of movement of the conveyor belts are required.
[0051] The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention:
1 , 1 a Felt belts 11 Periphery of felt belt 1 21 , 22 , 21 a , 22 a Rollers 3 , 3 a Deflecting rollers 31 , 32 , 33 , 34 Rollers 31 a , 32 a , 33 a Rollers 30 Bearing mounting 4 Paper web 5 , 5 a Tensioning units, units for detecting and for controlling tension 51 , 51 a Pressure-measuring apparatuses 52 , 52 a Measuring lines 53 , 53 a Control units 54 , 54 a Control lines 55 , 55 a Correcting units 6 , 6 a Movement correction units, units for detecting and for controlling the direction of movement 60 Carriage 61 , 61 a Sensors 62 , 62 a Control units 63 Support frame 64 Control lines 65 Correcting cylinders 66 Correcting pistons 67 Linkage | A conveying installation has least one endless conveyor belt guided via a plurality of rollers along a leading belt run for conveying material or products and a returning belt run, particularly for manufacturing a paper web with a wire belt or felt belt. At least one of the rollers has an adjustable mounting for adjusting and correcting a direction of movement of the conveyor belt. A tensioning unit for detecting and controlling a tension of the conveyor belt has a pressure-measuring apparatus disposed at the adjustable mounting. A movement correction unit for detecting deviations of a direction of movement of the conveyor belt from a correct movement and for correcting the movement includes a sensor that is disposed to monitor a lateral periphery of the conveyor belt. A sensor output of the sensor is used for adjusting the adjustable mounting of the one of the rollers. | 3 |
BACKGROUND
This invention relates to the area of rain gutter and down spout cleaning devices, and more particularly to rain gutter and downspout cleaning tongs.
The use of rain gutters to re-channel rain water from roof eaves is now fairly widespread. However, oftentimes homeowners and businesses neglect to properly clean out the rain gutters and downspouts of leaves, dirt and other debris which can cause the rain gutters to clog, and work inefficiently or not at all. Sometimes, debris will flow through the horizontal rain gutters and clog downspouts causing a backup of the rain water in the horizontal gutters.
Various tools are presently available to clean out rain gutters, including a variety of scraping tools and shovel-like implements for removing the debris. However, in the case of scraper implements, these implements simply accomplish scraping debris off of the bottoms and/or sides of rain gutters, pushing the debris to another location in the rain gutter and/or loosening up the debris, leaving the debris to be picked up and collected later. In the case of shovel-like scooper tools, if too much is attempted to be picked up in one shovel full, the debris will sometimes fall out. Moreover, these scraper-like tools and shovel tools are not very useful for cleaning out downspouts. Accordingly, there remains a need for a tool for cleaning rain gutters and downspouts which allows for the faster and more efficient removal of debris from the rain gutter and downspouts.
SUMMARY OF THE INVENTION
The invention provides a rain gutter cleaning tong having two gripping heads which extend from obtuse angled articulating arms. The arms are preferably spring loaded and the gripping surfaces are preferably adapted to capture debris in a pinching motion when the two obtuse angled arms are brought together. The front edge of the gripping heads can be flat to permit the gutter to be scraped while debris is being removed.
In order to ensure proper alignment of the two arms during operation, an arm guard can be affixed to one of the arms to maintain a parallel alignment of the arms during operation.
The rain gutter cleaning tongs can be formed of a strong material such as steel, aluminum or strong plastic. Other materials could also be used such as composite materials or even wood.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an exemplary embodiment of the rain gutter cleaning tongs in an open position.
FIG. 2 is a side view of the rain gutter cleaning tongs of FIG. 1 , but in a closed position.
FIG. 3 is a top plan detail showing an exemplary embodiment of a gripping head.
FIG. 4 is a top plan view of another exemplary embodiment of the cleaning tong gripping heads.
FIG. 5 is a top plan view of a yet another exemplary embodiment of the rain gutter cleaning tongs gripping heads.
FIG. 6 is a side view of another exemplary embodiment of the rain gutter cleaning tongs of the invention in an open position.
FIG. 7 is a detail of a portion of the lower arm of the rain gutter cleaning tong of FIG. 6 .
FIG. 8 is a partial side of another exemplary embodiment of the rain gutter cleaning tongs of the invention particularly adapted for cleaning rain gutter downspouts.
FIG. 9 is a front view of the exemplary rain gutter cleaning tongs of FIG. 8 .
FIG. 10 is a front view of another head design of the gutter cleaning tongs of FIG. 8 .
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the figures, FIG. 1 is a side view of an exemplary embodiment of a pair of rain gutter cleaning tongs 10 . The rain gutter cleaning tongs has two arms 12 and 14 which have at their distal ends gripping heads 16 and 17 , respectively. Arms 16 and 17 are connected at their proximal ends 18 and 20 , respectively, by a pivot 22 . The two arms 12 and 14 are preferably spring loaded. An optional arm guide 24 is mounted to one of the arms, e.g., arm 12 , and has a guide wall 26 which guides the movement of the arms in a parallel relationship relative to each other. Each of the arms 12 and 14 have two sections 12 a and 12 b , and 14 a and 14 b , respectively, which are in obtuse angular relationship with respect to each other. The obtuse angular relationship of the two sections of the arms 12 a and 12 b and 14 a and 14 b is important since the proximal sections of the arms 12 a and 14 a provide an upwardly angled grip portion where a user can squeeze these two sections 12 a and 14 a together to cause the gripping heads 16 and 17 on distal arm portion 12 b and 14 b , respectively, to be brought together, which is best shown in FIG. 2 . This takes place while, for example, the distal arm portion 12 b is used to scrape the bottom of the gutter. The lower arm 12 to which the arm guide 24 is attached will, in use, be the lower arm which is placed in contact with the gutter. Again, by simply bringing the two arms together, debris can be grasped and picked up and removed from the rain gutter and/or the downspout. Again, the proximal portions 12 a and 14 a are important since they allow users to operate the rain gutter cleaning tongs without placing the users hand in the gutter. The angle α between the distal and proximal parts is between about 100 and 170 degrees and more preferably between about 135 to about 160 degrees, depending on the relative lengths of the proximal and distal portions of the arms 12 and 14 .
Referring to FIG. 3 , there is shown a first exemplary embodiment of gripping heads 16 and 17 . In the first exemplary embodiment, the gripping heads 16 , 17 comprise a generally flat and rectangular plate 30 and is shown with optional protrusions 32 formed thereon for providing a better grip with the debris being captured. A front edge 34 is preferably relatively straight and can be used for scraping the bottom and/or sides of the rain gutter.
Referring to FIG. 4 , there is shown a second exemplary embodiment of a gripping head 40 of the rain gutter cleaning tongs which has scalloped edges 42 and is also shown with optional gripping protrusions 44 extending from a generally flat plate 46 . As with the first embodiment of the gripping head, a relatively flat front 46 may be provided at a front of the gripping surface. The gripping head 40 extends from the distal end of the arms 12 b and 14 b and can be preferably be formed together therewith.
Referring now to FIG. 5 , there is shown a third exemplary embodiment of the gripping head 50 of the rain gutter cleaning tongs. This embodiment is similar to that shown in FIG. 4 except it has an extension portion 52 at a leading edge thereof. As with other embodiments, optional protrusions 54 can be located on the gripping head to provide for better gripping action on debris and the gripping surface 52 can extend from the distal ends 12 b and 14 b of the arms.
The gripping heads 16 , 17 , 40 , 50 may also be shaped to include concavities, or to be curved if desired.
FIG. 6 is a side view of another exemplary embodiment of the rain gutter cleaning tongs 60 of the invention in an open position. This embodiment has a lower arm portion 62 and an upper arm portion 64 . The lower arm portion 62 has a proximal portion 62 A and a distal portion 62 B, with the proximal portion 62 A angled slightly upwardly from the distal portion 62 B. A gripping head 66 is provided at the distal portion 62 B and can, if desired, be slightly angled up from the distal portion 62 B. A debris tray 70 is provided on the upper surface of the distal portion 62 B and functions to carry additional debris. Alternately, the debris tray 70 can be integrated into the shape of the arm portion 62 . The proximal portion 62 B has a pivot end 68 . The upper arm portion 64 has a proximal portion 64 A and a distal portion 65 B, with the proximal portion 62 A angled slightly downwardly from the distal portion 64 B. A gripping head 72 is provided at the distal portion 64 B and can, if desired, be slightly angled down from the distal portion 64 B. The proximal portion 64 B has a pivot end 74 which connects to the pivot end 68 of the lower arm 62 by a pivot 76 . A spring 78 biases the lower and upper arms away from each other.
FIG. 7 is a detail of a portion of the lower arm 62 of the rain gutter cleaning tong 60 of FIG. 6 , showing the debris tray 70 on the lower arm 62 . The debris arm 70 can optionally have low rising walls 80 for added strength and gripping action. Although the tray is shown as being relatively flat, it can have other shapes and contours. The gripping head 66 has an appearance similar to that shown in FIG. 5 , e.g. with a shovel tip 82 and is shown without optional protrusions 54 . If desired, the gripping head 66 can have other shapes, can be cupped, etc.
FIG. 8 is a partial side of another exemplary embodiment of the rain gutter cleaning tongs 90 of the invention particularly adapted for cleaning rain gutter downspouts. These tongs have arms 92 and 94 , with gripping heads 96 and 98 , respectively, having inwardly facing profiles that are adapted for inserted into an opening of a rain gutter downspout.
FIG. 9 is a front view of the exemplary rain gutter cleaning tongs 90 of FIG. 9 , and shown the gripping heads 96 and 98 , respectively, as being arc-shaped with their concavities facing each other. Alternately, the gripping heads can be generally U-shaped, or have other shapes with inwardly facing concavities that face each other that permit the tongs to be fix down into an opening of rain gutter downspout to pull out debris from therein, such as the U-shaped heads 100 shown in FIG. 10 .
It is to be understood that the invention is not limited in its application to the details and construction and arrangements of the components set forth in the above description or illustrations and drawings. The invention is capable of other embodiments that are being practiced and carried in various ways. It also is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. | Rain gutter and downspout cleaning tongs. The rain gutter cleaning tongs include a pair of arms, each having a distal portion and a proximal portion that are arranged at obtuse angles relative to each other. A gripping head is located at a distal end of the distal portion of each arm. The proximal arm portions are pivotally attached to each other and are spring loaded to bias their gripping surfaces away from each other. Optionally, a guide is attached to one of the arms for guiding the two arms relative to each other during operation. | 4 |
RELATED APPLICATION
This claims the priority of U.S. provisional patent application Serial No. 60/139,580, filed Jun. 17, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to an apparatus for the percutaneous positioning of a radiopaque marker for identifying the location of a lesion in a stereotactic biopsy procedure. More particularly, the invention relates to an introducer having a hollow cannula in combination with a movable stylet and a radiopaque marker disposed within the cannula and ejected from it by movement of the stylet.
2. Related Art
Tissue biopsies are commonly performed on many areas and organs of the body where it is desirable to ascertain whether or not the biopsied tissue is cancerous. Often, a lesion or other tissue to be biopsied is identified through use of an imaging technique such as a computerized axial tomography (CAT) scan, ultrasonography, and mammography.
One problem commonly encountered, especially in breast biopsies, is that the lesion is so small that the biopsy reduces its size to the extent that it is no longer visible by the imaging method employed. In such circumstances, it is desirable to place a radiopaque marker at the site of the biopsy to enable the medical practitioner subsequently to locate the lesion quickly and accurately in the event complete removal of the affected tissue is indicated. This problem is currently met by placing a radiopaque marker at the biopsy area by means of a cannula or similar device housing the marker.
More particularly, one of the markers heretofore in use is a staple-type clip. The clip is introduced through a large-diameter cannula, specifically one of 11 gauge.
Some practitioners employ an embolization coil as a marker. This requires them to find a cannula or hollow needle of a size to receive the coil and some means to force the coil through the needle, all the while trying to keep these components together and sterile.
Prior devices for marking a biopsy area have several other disadvantages. A significant disadvantage is that the marker is not always completely ejected from the cannula or can be drawn back into or toward the cannula by the vacuum created upon the withdrawal of the cannula, which results in the marker being moved from the intended site, leading to inaccurate identification of the location of the biopsy area. A second major disadvantage is that current markers have a tendency to migrate within the tissue, also causing error in determining the biopsy location.
SUMMARY OF THE INVENTION
The present invention provides a biopsy marking apparatus for the percutaneous placement of a marker at a biopsy site in a tissue mass to facilitate subsequent determination of the location of the biopsy site. The biopsy marking apparatus comprises an introducer having a handle to be grasped by a user, a cannula, a stylet, and a radiopaque marker. The cannula has a proximal end mounted to the handle and a distal end defining an insertion tip. The stylet is slidably received within the cannula for movement between a ready position in which a distal end of the stylet is spaced inwardly from the cannula tip to form a marker recess between the distal end of the stylet and the cannula tip, and an extended position in which the distal end of the stylet extends at least to the cannula tip to effectively fill the marker recess.
A plunger is movably mounted to the handle and operably engages the stylet, the plunger being movable between a first position and a second position for moving the stylet between the ready position and the extended position.
A latch is provided for fixing the stylet in the extended position to prevent retraction of the stylet from that position.
A radiopaque marker is disposed within the marker recess, whereby, when the plunger is moved between the first and second positions, the stylet is moved from the ready to the extended position to eject the radiopaque marker from the marker recess, and the latch fixes the stylet in the extended position to prevent the return of the marker to the marker recess.
The latch preferably comprises a detent on either the plunger or the handle and a catch on the other, the catch being receivable within the detent as the plunger is moved from the first to the second position.
In another aspect, the invention also provides a radiopaque marker having a marker body and an anchor extending away from the body for fixing the location of the radiopaque marker in a tissue mass by the tissue mass prolapsing about the anchor. Preferably, the body has an interior hollow portion forming an air trap to enhance the ultrasound characteristic of the radiopaque marker.
Other features and advantages of the invention will be apparent from the ensuing description in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a plan view of an introducer used to place a radiopaque marker at a biopsy location in accordance with the invention;
FIG. 2 is an enlarged sectional view of the area II of FIG. 1, illustrating the position of a radiopaque marker within the introducer prior to ejection;
FIG. 3 is an enlarged sectional view of the area III of FIG. 1, illustrating the arrangement of a handle, a plunger, and a stylet of the introducer;
FIG. 4 is a sectional view taken along line 4 — 4 of FIG. 1 and illustrating the introducer in a ready condition;
FIG. 5 is a sectional view taken along line 4 — 4 of FIG. 1 and illustrating the introducer in a discharged condition;
FIG. 6 is an enlarged view of a first embodiment of a radiopaque marker according to the invention;
FIG. 7 is an enlarged view of a second embodiment of a radiopaque marker according to the invention;
FIG.8 is an enlarged view of a third embodiment of a radiopaque marker according to the invention;
FIG. 9 is an enlarged view of a fourth embodiment of a radiopaque marker according to the invention;
FIG. 10 is a partially broken away perspective view, greatly enlarged, of a fifth embodiment of a radiopaque marker according to the invention;
FIG. 11 is a plan view of the radiopaque marker of FIG. 10;
FIG. 12 is a greatly enlarged view of a sixth embodiment of a radiopaque marker according to the invention;
FIG. 13 is a greatly enlarged view of a seventh embodiment of a radiopaque marker according to the invention;
FIG. 14 is a greatly enlarged view of an eighth embodiment of a radiopaque marker according to the invention; and
FIG. 15 is a greatly enlarged view of a ninth embodiment of a radiopaque marker according to the invention.
DETAILED DESCRIPTION
FIGS. 1 to 4 illustrate a biopsy marking apparatus 10 according to the invention, which is capable of the percutaneous placement of a radiopaque marker at the location of a tissue biopsy. The biopsy marking apparatus 10 comprises an introducer 12 and a radiopaque marker 14 (FIG. 2) contained within the introducer 12 . The introducer 12 includes a handle 16 having a hollow interior 18 . The handle 16 comprises a grip portion 20 from which extends a tapered nose portion 22 . The grip portion 20 defines a rear opening 24 that provides access to the hollow interior 18 . A pair of detents 26 are formed in the grip portion 20 near the rear opening 24 . Channels 28 are formed on the interior surface of the grip portion 20 and extend from the rear opening 24 to the detents 26 .
The nose portion 22 comprises a guide passage 30 extending from the tip of the nose portion 22 to the hollow interior 18 of the handle 16 . The guide passage 30 decreases in diameter inwardly from the tip of the nose portion to form a cannula seat 32 . Alternatively, the diameter of the guide passage 30 may be substantially equal to or slightly smaller than the outer diameter of a cannula 34 , which in any case is press-fit within the cannula seat 32 . As is customary, the cannula is formed with a hollow interior 36 and a sharpened tip 38 .
A stylet 40 comprising a shaft 42 and a base 44 is received within the hollow interior 18 of the handle 16 in a manner such that the shaft 42 extends through the guide passage 30 and into the cannula interior 36 and the stylet base lies within the hollow interior 18 .
A plunger 50 comprises a cylindrical body 52 from which extend a pair of catches 54 at diametrically opposed positions. The cylindrical body 52 is sized so that it is slidably received within the rear opening 24 of the handle 16 , where it is so oriented with respect to the handle that the catches 54 are aligned with the guide channels 28 .
It will be recognized that the foregoing construction provides a biopsy marking apparatus which may be preassembled as a unit and prepackaged, all under sterile conditions, thereby affording the practitioner substantially greater convenience and reliability. Such a construction also permits use of a narrower cannula, which may be of 14 gauge or smaller.
In operation, the introducer 12 begins in the ready condition shown in FIG. 4 . In this condition, the stylet shaft is received within the cannula but does not extend to the cannula tip 38 , thereby forming a marker recess 46 within the cannula 34 , the radiopaque marker 14 is disposed within the marker recess 46 , and the plunger 50 is in a position relative to the handle 20 in which the catches are outside the handle; that is, they are not received within the detents 26 . However, the plunger 50 is so oriented with respect to the handle that the catches 54 are aligned with the guide channels 28 .
With the introducer in the ready condition, the cannula is positioned so that its tip is at or near the location of a tissue mass where a biopsy has been taken. Preferably, the cannula tip is positioned by using imaging systems. The cannula tip 38 can be designed for enhanced visibility using common imaging systems, such as CAT scan, ultrasonography and mammography. Suitable cannula tips are disclosed in U.S. Pat. No. 5,490,521, issued Feb. 13, 1996 to R. E. Davis and G. L. McLellan, which is incorporated by reference. Ultrasound enhancement technology is also disclosed in U.S. Pat. No. 4,401,124, issued Aug. 30, 1983 to J. F. Guess, D. R. Dietz, and C. F. Hottinger; and U.S. Pat. No. 4,582,061, issued Apr. 15, 1986 to F. J. Fry.
Once the cannula is positioned at the desired location, the plunger 50 is moved from its first or ready condition as illustrated in FIGS. 1 to 4 to a second or discharged condition in which the catches 54 are received within the detents 26 to lock the plunger 50 in the discharged condition and the stylet shaft extends beyond the cannula tip 38 . The catches 50 and detents combine to function as a latch for locking the plunger in the discharged condition. As the plunger 50 is moved from the ready condition to the discharged condition, the plunger 50 drives the stylet base 44 forward to advance the stylet shaft 42 within the cannula interior 36 . As the stylet shaft 42 is advanced, the radiopaque marker 14 is ejected from the marker recess 46 through the cannula tip 38 and into the tissue at the biopsy location.
It is preferred that the stylet shaft 42 be sized in a manner such that when the plunger 50 is in the discharged condition the stylet shaft 42 extends beyond the cannula tip 38 to ensure the complete ejection of the radiopaque marker 14 from the marker recess 46 . The extension of the stylet shaft 42 beyond the cannula tip 38 also prevents the radiopaque marker 14 from being drawn back into the marker recess upon the removal of the introducer 12 from the tissue mass, which can occur as the tissue mass collapses and is drawn towards and into the cannula by the resilient nature of the tissue mass and the creation of a vacuum by the cannula as it is withdrawn from the tissue.
The rate at which the plunger 50 is moved from the ready condition to the discharged condition is preferably manually controlled by the user to control the rate at which the marker 14 is ejected into the tissue mass. Manual control of the ejection rate of the radiopaque marker provides the user with the ability to adjust the position of the cannula tip as the marker is being ejected and thereby permits additional control of the final location of the marker within the tissue mass. In other words, “on-the-fly” adjustment of the cannula tip during positioning of the marker 14 enables a more accurate placement of the marker.
The biopsy marking apparatus 12 may be placed in a safety condition (not shown) before packaging or use by rotationally orienting the plunger 50 with respect to the handle 16 so that the catches 54 are out of alignment with the guide channels 28 , whereby the plunger cannot be depressed or advanced within the handle. It will be apparent that the marking apparatus can be placed in the ready condition previously described simply by rotating the plunger relative to the handle until the catches 54 are aligned with the guide channels 28 .
It will also be apparent that the biopsy marking apparatus 10 may incorporate or be fitted with any one of several known trigger devices, some of them spring-loaded, for advancement of the plunger 50 . Such a trigger device is disclosed, for example, in U.S. Pat. No. 5,125,413, issued Jun. 30, 1992 to G. W. Baran.
It should be noted that as a variation of the foregoing procedure the cannula employed during the biopsy procedure might be left in place with its tip remaining at the site of the lesion. The introducer 12 of the present invention would then be directed to the site through the biopsy cannula or, alternatively, the marker 14 of the present invention would be introduced to the biopsy cannula and ejected from its tip into the tissue mass by fitting the biopsy cannula to the introducer 12 in place of the cannula 34 .
The radiopaque marker 14 used in combination with the introducer 12 to mark the location of the tissue biopsy should not only be readily visible using contemporary imaging techniques but it should not migrate within the tissue from the position in which it is initially placed. FIGS. 6 to 15 disclose various embodiments of radiopaque markers 14 that are highly visible using contemporary imaging techniques and are resistant to migration in the tissue.
FIG. 6 illustrates a first embodiment 60 of a radiopaque marker comprising a coil spring 62 from which extend radiopaque fibers 64 . The coil spring 62 is preferably made from platinum or any other material not rejected by the body. The coil spring 62 is wound to effectively form a hollow interior comprising one or more air pockets, which are highly visible using contemporary ultrasound imaging techniques. The radiopaque fibers 64 are preferably made from Dacron, which is also highly visible using current imaging techniques.
The radiopaque marker 60 is highly visible using any of the commonly employed contemporary imagining techniques because of the combination of reflective surfaces formed by the coils, the hollow interior and the air pockets of the coil spring 62 , as well as the radiopaque fibers 64 .
The coil spring 62 is pre-shaped prior to being loaded into the marker recess 46 so that it tends to form a circular shape as shown in FIG. 6 after it is ejected from the marker recess 46 . The circular shape tends to resist migration within the tissue.
FIG. 7 illustrates a second embodiment 70 of a radiopaque marker having a star-burst configuration comprising a core 72 with multiple fingers 74 extending from the core.
FIG. 8 illustrates a third embodiment 80 of a radiopaque marker that is similar to the star-burst marker 70 in that it comprises a core 82 from which extend three fingers 84 . Each of the fingers includes radiopaque fibers 86 , which are preferably made from Dacron or a similar material.
FIG. 9 illustrates a fourth embodiment 90 of a radiopaque marker having a generally Y-shaped configuration comprising an arm 92 from which extend diverging fingers 94 . The arm and fingers 92 , 94 are preferably made from a suitable resilient metal such that the fingers can be compressed towards each other and the entire radiopaque marker 90 stored within the marker recess 46 of the cannula. Upon ejection of the marker 90 from the marker recess 46 into the tissue mass, the fingers 94 will spring outwardly to provide the marker 90 with an effectively greater cross-sectional area.
In addition to providing the marker 90 with an effectively greater cross-sectional area, the tips of the fingers 94 , together with the free end of the arm 92 , effectively form points of contact with the surrounding tissue mass that help to anchor the marker 90 in its release condition to prevent migration through the tissue mass.
FIG. 10 illustrates a fifth embodiment 100 of a radiopaque marker having a wire-form body in a horseshoe-like configuration comprising a rounded bight portion 102 from which extend inwardly tapering legs 104 , each of which terminate in curved tips 106 . The entire marker 100 preferably has a circular cross section defining a hollow interior 108 . The hollow interior provides for the trapping of air within the marker 100 to improve the ultrasound characteristics of the marker 100 .
The curved bight portion 102 and legs 104 preferably lie in a common plane. However, the tips 106 extend away from the legs 104 and out of the common plane so that the tips 106 will better function as anchors for the tissue that prolapses about the tips 106 once the marker 100 is ejected from the marker recess 46 and the introducer 12 is withdrawn from the tissue mass.
FIG. 12 illustrates a sixth embodiment 110 of a radiopaque marker that is similar to the horseshoe-like fifth embodiment marker 100 in that it comprises a bight portion 112 from which extend legs 114 , which terminate in tips 116 . The legs 114 of the marker 110 are crossed relative to each other, unlike the legs of the marker 100 , providing the marker 110 with an effectively larger cross-sectional diameter. The tips 116 are oriented at approximately 90° relative to the legs 114 to form anchors. The marker 110 also has a hollow interior 118 for enhanced radiopaque characteristics.
Though, as illustrated in FIG. 12, the tips 116 of the marker 110 are oriented at approximately 90° with respect to the legs 114 , it is within the scope of the invention for the tips 116 to extend at substantially any angle with respect to the legs 114 . The tips 116 also need not extend away from the legs in the same direction. For example, the tips 116 could extend in opposite directions from the legs 114 .
FIG. 13 illustrates a seventh embodiment 120 of a radiopaque marker having a generally helical configuration comprising multiple coils 122 of continuously decreasing radius. The helical marker 120 is preferably made from a radiopaque material and has a hollow interior 124 to enhance its radiopaque characteristics. The decreasing radius of the coils 122 provides the marker 120 with multiple anchor points created by the change in the effective cross-sectional diameter along the axis of the helix. In other words, since the effective cross-sectional diameter of each coil is different from the next and each coil is effectively spaced from adjacent coils at the same diametric location on the helix, the tissue surrounding the marker 120 can prolapse between the spaced coils and each coil effectively provides an anchor point against the tissue to hold the marker 120 in position and prevent its migration through the tissue mass.
FIG. 14 illustrates an eighth embodiment 130 of a radiopaque marker comprising a cylindrical body 132 in which are formed a series of axially spaced circumferential grooves 134 . The spaced grooves 134 form a series of ridges 136 therebetween on the outer surface of the cylindrical body 132 . The cylindrical body 132 preferably includes a hollow interior 138 .
The alternating and spaced ridges 136 and grooves 134 provide the marker 130 with a repeating diameter change along the longitudinal axis of the cylindrical body 132 . As with the helical marker 120 , the grooves 134 between the ridges 136 provide an area in which the tissue surrounding the marker 130 can prolapse thereby enveloping the ridges 136 , which function as anchors for preventing the migration of the marker 130 in the tissue mass.
FIG. 15 illustrates a ninth embodiment 140 of a radiopaque marker comprising a cylindrical body 142 having an axial series of circumferential grooves 144 whose intersections with adjacent grooves form ridges 146 . The cylindrical body 142 preferably includes a hollow interior 148 . An anchor 150 extends from the cylindrical body 142 . The anchor 150 comprises a plate 152 connected to the cylindrical body 142 by a wire 154 .
The grooves 144 and ridges 146 of the maker 140 provide anchors in the same manner as the grooves 134 and ridges 136 of the marker 130 . The anchor 150 further enhances the non-migrating characteristics of the marker 140 by permitting a large portion of the surrounding tissue mass to prolapse between the plate 150 and the cylindrical body 142 .
The fifth through the ninth embodiments all preferably have a wire-form body. The various wire-form body shapes can be formed by stamping the shape from metal stock or the bending of a wire.
It should be noted that virtually all of the embodiments of the radiopaque marker described as being hollow can be made without a hollow interior. Similarly, those without a hollow interior can be made with a hollow interior. The hollow interior improves the ultrasound characteristics of the particular marker beyond the inherent radiopaque and ultrasound characteristics attributable to the marker shape and material. In practice, the use of the hollow interior is limited more by manufacturing and cost considerations rather than by performance.
Also, the shape of each marker can be altered to improve or enhance its non-migrating characteristics by adding an express anchor such as that disclosed in connection with the marker 140 or by modifying the marker to provide more anchor points as may be compatible with the basic configuration of the marker.
The combination of the enhanced radiopaque characteristics of the markers and the enhanced non-migrating features result in markers that are superior in use for identifying biopsy location after completion of the biopsy. The ability to accurately locate the biopsy site greatly reduces the amount of tissue that must be removed in a subsequent surgical procedure if the biopsy is cancerous. Additionally, the marker further enhances the ability to use percutaneous methods for removing the entire lesion, reducing the trauma associated with more radical surgical techniques.
The radiopaque markers described and illustrated herein are smaller than the staple-type clip and embolization coil used heretofore, thereby permitting a cannula of 14 gauge or less.
While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit. | A biopsy marking apparatus for placing a radiopaque marker at the location of a percutaneous biopsy. The biopsy marking apparatus comprises an introducer in combination with a radiopaque marker. The introducer ejects the radiopaque marker at the location of the biopsy. The introducer is configured to completely eject the radiopaque marker and prevent it from being subsequently drawn into the introducer as the introducer is removed from the biopsied tissue mass. The radiopaque marker has enhanced radiopaque characteristics and enhanced non-migration characteristics. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This Patent Application is a Divisional of, and claims priority to under 35 U.S.C. §120, U.S. patent application Ser. No. 09/623,847, filed on Jul. 31, 2000, now U.S. Pat. No. 6,952,998, entitled, “Minimum Till Seeding Knife” and having Terry Emerson Summach and Bradley T. Summach as the Inventors. The full disclosure of U.S. patent application Ser. No. 09/623,847 is hereby fully incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to a method of farming, a farm implement and a knife or knife assembly which may be used as part of no-till or minimum-till farming practices primarily for placement in the ground of seed and/or fertilizer and other materials. The invention works in all field conditions, and in particular it operates with minimum soil disturbance in minimum till and zero till farming practices, better allows passage of trash in such practices, and does not cause the hair-pinning of crop residue as is often caused by disc-type openers. As a result, the method provides a simple, reliable and inexpensive procedure and tool which can be used in all farming practices so that multiple types of equipment are not required by farms for various soil conditions.
BACKGROUND OF THE INVENTION
Important advantages have been found in soil preparation, and seed and fertilizer delivery in employing no-tilling or minimum tilling methods which cause minimum disturbance to the soil. This is particularly important in dry land conditions where the soil is subject to moisture and topsoil loss if conventional tilling methods are used.
It is usually desirable when employing no-till farming practices to disturb the soil surface as little as possible. The surface will be covered with the residue from previous crops, and the surface layer will contain old root structure. This plant material can serve to retain moisture below the surface and to assist in securing the soil against runoff and erosion. Particularly in dry land conditions it is beneficial to retain this covering. Tools available to seed into zero till or minimum till conditions have encountered problems.
Fertilizing prior to seeding is a method utilized by some farmers. While broadcasting the fertilizer on the surface is a method that does not disturb the surface, it is very inefficient, as much of the fertilizer can be lost due to runoff surface water. Placement of fertilizer at a level well below the level that seed will be place has been utilized. Tilling and fertilizing is disclosed in Great Britain patent No. 1,574,412 issued to Ede in 1980. In that prior art device an angled tilling blade for deeply penetrating the soil is shown with a central duct and a number of separated orifices for providing fertilizer in vertically separated bands. To maintain those desirable characteristics of the surface structure in zero till conditions major surface disturbance is not acceptable.
Zero till devices have been developed to deposit high concentration bands of fertilizer in furrows. If the seed is placed in close proximity to a high concentration of fertilizer, burning of the newly germinated plant will result. To avoid this one technique has been to separate the seeds by a soil layer from the fertilizer.
In the U.S. Pat. No. 5,396,851 issued to Beau jot in 1995 fertilizer is deposited by a first vertical blade which cuts a deeper furrow. A second blade cuts a second furrow in which to deposit seed. Other devices such as disclosed in U.S. Pat. No. 4,798,151 issued to Rodrigues in 1989 form a deep fertilizer furrow, and a shallower shelf above the fertilizer on which to plant the seed. In both cases, to minimize soil disturbance only a narrow furrow is cut. It is grown to prepare soil when using traditional tilling methods to cut out weed growth prior to or at the time of a seeding operation.
U.S. Pat. No. 1,085,825 issued in 1914 to Rubarth discloses a subsurface tilling blade for use with a traditional turning plowshare. The tilling blade its curved to angle the cut and includes a horizontal blade on the opposite side. The blades are shown to include an arrangement in overlapping fashion to cut the full width of the subsurface to remove weeds and old growth. Seeding and fertilizing are separate operations.
U.S. Pat. No. 5,005,497 issued in 1991 to Kolskog discloses a deep banding knife for delivering seed and fertilizer with an additional transverse rod for disrupting weed growth. The banding knife makes a substantially vertical cut in the soil. The rod disrupts the subsoil to loosen soil and cut weeds. The transverse rods can be arranged in parallel to remove weeds completely.
Adaptations of these concepts have been used for deep placement of fertilizer in fully tilled row-crop situations.
In traditional zero till farming practice, no till furrows are separated by undisturbed areas of soil and weeds. Typically a herbicide application is necessary to control weeds which would otherwise compete with the crop growth and possibly contaminate the harvest. Herbicide is an expensive additional operation.
A further problem encountered by seeding implements particularly in zero till conditions is the accumulation of trash during seeding which impairs their operation. Many devices for seeding in zero till conditions provide a blade which penetrates the soil substantially vertically. Trash gathers around the blade and is dragged with the device. This can impair operation. It also removes the desired moisture retaining cover. In an effort to combat this problem the Beau jot discussed above is adapted to lift over obstacles, such as crop stubble, interrupting seeding. Such a technique reduces trash accumulation, but reduces seeding efficiency.
A deep sowing tool has been disclosed for rice seeding in relatively wet conditions in USSR patent No. 372,962 issued in 1973 using a tilling blade and deep seed delivery to cover seeds and to reduce the need to water. This is not suitable for zero tilling, as tilling using this tool is deep in order to cause deep soil aeration. The blade of this prior art design penetrates the soil essentially vertically, with an angled blade portion cutting more deeply. The blade portion of this design would also be subject to accumulation of trash.
Significant soil disruption occurs as vertical furrow parting tools are drawn through surface soils at relatively high velocity, especially in high trash conditions or with unprepared soils. Additional energy is imparted to the soil, throwing and turning the soil.
It is desired for minimum soil disruption to pass through the soil surface and any trash cleanly without undue lifting or turning of the soil. While disk openers have the ability to cut through most trash, some straw will not cut easily, and is pushed into the furrow, a result commonly called hairpinning. This can displace seeds, as well as drying out the seed bed. As well, effective no-till disc opener designs are relatively expensive.
The prior art fails to provide teaching to or a suggestion of any method or device for operation in zero or min-till conditions which provides tilling and/or seeding, fertilizing or weed clearing in a single pass without significantly disrupting the soil or the order of the soil structure and avoid hairpinning. It is desired to provide the advantages of tilling seeding and weed clearing without trash accumulation.
SUMMARY OF THE INVENTION
The invention provides a ground opening knife for use in no-till or minimum-till farming operations primarily in conjunction with seed and/or fertilizer placement adjacent a soil cut-line generally in the direction of travel comprising connection mechanism adapted to mount the knife on a farm implement, and a blade comprising a lower portion, said lower portion adapted to open soils along the direction of travel, said lower portion adapted to extend into the soil but no more than 6 inches measured vertically, said lower portion adapted to be oriented in a direction having a 1 st component of between 30 and 60 degrees below horizontal in a plane transverse to the said direction of travel, and a 2 nd component forward in the direction of travel.
The knife may include an upper portion adjacent said lower portion adapted to extend away from the surface of the soil and is adapted to pass through materials or residue on the surface of the soil or associated with the passage of the knife though the soil.
The knife may also include an extension extending substantially laterally from said lower portion and provides support for material delivery tubes at various locations along the blade and extension.
The knife may also include in extension to form a secondary furrow adjacent the said lower portion intermediate the surface of the soil and the lowermost end of the said blade and may include an extension of said leading edge generally forward in the direction of travel.
The invention also provides a method of no-till or minimum-till farming operation primarily in conjunction with seed and/or fertilizer placement adjacent a soil cut-line aligned generally in the direction of travel comprising forming a furrow in the soil extending from said soil cut-line no more than 6″ into the soil measured vertically, and forming the said furrow by cutting the soil along a direction having a 1 st component of between 30 and 60 degrees below the horizontal in a plane transverse to the said direction of travel, and a 2 nd component forward in the direction of travel.
The method substantially minimizes any disturbance of the cut soil either above the said furrow or below it or both whether distribution or particulate or other materials is included at the same time within the furrow being formed.
The invention also provides a no-till or minimum-till farm implement primarily for use in conjunction with cultivation or materials placement adjacent a plurality of soil cut-lines generally parallel and in the direction of travel comprising a support frame structure, a plurality of around opening knives attached to said support structure, spaced from each other in a direction transverse to the direction of travel of the implement and each adapted to cut the soil along adjacent ones of said cut-lines, each said knife having a blade comprising a lower portion, said lower portion adapted to extend into the soil but no more than 6 inches measured vertically between the surface of the soil and the lowermost extremity of the said blade, said lower portion adapted to be oriented in a direction having a 1 st component of between 30 and 60 degrees below horizontal in a plane transverse to the said direction of travel, and a 2 nd substantial component forward in the direction of travel.
The farm implement may include an extension of the blade extending laterally across a substantial portion of said spacing between adjacent said cut-lines when viewed in a plan view.
The invention will be more clearly understood to those skilled in the art with the following detailed description of preferred embodiments with reference of the following drafting's in which:
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a plan view of a single knife according to the present invention;
FIG. 2 is a side view of the embodiment of FIG. 1 ;
FIG. 3 is a front view of the embodiment of FIG. 1 ;
FIG. 4 is a plan view of a further embodiment according to the present invention;
FIG. 5 is a side view of the embodiment of FIG. 4 ;
FIG. 6 is a front view of the embodiment of FIG. 4 ;
FIG. 7 is an isometric view of the embodiment of FIG. 4 arranged on an implement for operation; and
FIGS. 8-1 through 8 - 3 are front, top and side elevations respectively of another embodiment of the invention adapted for double shooting of materials in seeding. Like references are used throughout to designate like elements.
FIG. 9 is a plan view of an agricultural implement for planting seeds. Which incorporates the seeding knives of the invention;
FIG. 10 is a horizontal front elevation of an angled seeding knife, in use;
FIG. 11 is a side elevation of the knife of FIG. 10 , from the left side of FIG. 10 , and FIG. 11 includes a cross-section on the line X—X of FIG. 10 ;
FIG. 12 is a rear elevation of knife of FIG. 10 ;
FIG. 13 is a right side elevation of the knife of FIG. 10 ;
FIG. 14 is a cross-section of a blade of the knife of FIG. 10 , the cross-section being taken in a plane at right angles to a knife-edge of the blade;
FIG. 15 is a front elevation corresponding to FIG. 10 of another angled seeding knife;
FIGS. 16 , 17 , 18 are further elevations of the knife of FIG. 15 ;
FIG. 19 is a pictorial elevation of a replaceable tip, of the knife of FIG. 15 ;
FIG. 20 is an elevation of the body of the knife of FIG. 15 , and is shaded to show the configuration thereof.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiment of the single knife of the present invention is as shown generally at 10 in FIGS. 1–3 . In FIG. 1 , arrow designated 1 shows the direction of travel of the knife 10 through the soil when working.
As shown in FIG. 7 , the knife 10 is typically attached to a cultivator-type frame or implement generally indicated at 2 to be towed by a tractor in a direction of travel 1 primarily in cooperation with a tow-between or tow-behind seed supply carrier (not shown) having a repository of seed, fertilizer or other material and fluid passages for connection with the knife 10 . The frame 2 is shown in general outline only.
The knife 10 includes a shank 12 which serves as a connection for mounting the knife 10 selectively on the implement in a known fashion ( as at 3 in FIG. 7 ). As shown in FIG. 7 , an appropriate spacing 4 for seeding or tilling operations will be selected, determining the number and spacing of knives 10 mqunted across the width of the implement. The shank 12 preferably has a pair of holes 13 (See FIG. 1 ) for mounting bolts or the mounting could be provided in any conventional manner such as a knock-on taper mounting system or other known mounting mechanism.
Knife 10 includes a blade 14 formed to penetrate the soil along a soil-cut line 11 oriented in the direction of travel. Penetration of the soil occurs at an angle A which has both substantial lateral (A 1 ) and forward (A 2 ) components as shown in FIGS. 3 and 1 , respectively, of approximately 35–55 degrees to the surface 5 of the soil to be tilled. Preferably each of lateral and forward components A 1 and A 2 respectively is 45 degrees. Soil penetration (d) is by the lower portion of the blade 14 as at 6 in FIG. 3 and is no more than 6 inches, consistent with minimum till or no till farming practices.
The lateral component A 1 of angle A determines the final angle of the furrow cut into the soil. The angled furrow allows seed to be planted ensuring soil cover.
The blade is also angled significantly forwardly by component A 2 of angle A. Preferably, a lower end 17 of a cutting edge 16 is significantly in advance of the upper end 15 of the cutting edge 16 . Deeper soil is cut and lifted in advance of cutting the surface soil allowing the surface to be cut along cut-line 11 more easily and without undue lateral disruption. Vertical motion is limited. The forward component of angle A of the blade cuts through the surface and trash layers last without accumulating trash on the knife 10 . Leading edge 16 is preferably continuous from its lower end 17 to its upper end 15 .
The blade 14 had a leading cutting edge 16 and a pair of opposing angled surfaces 18 a and 18 b which form a wedge shaped profile. The profile shape is determined by the furrow opening required. Edge 16 may be in 2 parts, one below the surface and another above, but preferably extends continuously above the surface sufficient to move trash and other materials aside without accumulation. Also preferably it is formed aligned with the leading edge of the lower portion of the blade 14 .
Preferably surface 18 b is inclined slightly from the horizontal to avoid sliding contact with the soil below the blade 14 and minimize soil disturbance below the cut.
Also preferably, the rear surface of blade 14 is also angled forwardly and downwardly so as to assist in the creation of a small temporary cavity behind the blade as it travels through the soil.
The overall effect is to provide a method and knife whereby primarily vertical motion is imparted to the soil to permit the blade 14 passage and then a return substantially vertical motion is permitted whereby the soil may return to its approximate original location.
Adjacent the trailing surface 20 of the blade 14 , a conduit 22 may be secured for delivering seeds or other material.
The conduit 22 may have an outlet 24 near the lower end 17 of the blade 14 as shown in FIGS. 1 and 2 , and as a result the outlet 24 is adjacent the lowest area of the furrow cut by the blade 14 . The seed delivery conduit 22 is protected from damage as the blade 14 is advanced through the soil by the blade body 14 . The outlet 24 is also shielded from becoming clogged with earth by this arrangement.
Additional conduits along the blade for fertilizer, herbicide or other materials may be similarly located (not shown in FIGS. 1–3 )
The preferred method provides the steps of forming and angled no-till or minimum till furrow by a knife 10 which furrow cutting motion has both a substantial forward and a substantial lateral component both above and below the ground to a depth (d) of 6 inches.
In a preferred method, seed and fertilizer are scattered from adjacent outlets in a pattern across the width of the furrow. The outlets may be spaced apart to appropriate depths and separation, for example, placing fertilizer outlet at the lowest end of the blade for the deepest application and a seed outlet spaced above it on the angled blade 14 .
Another preferred embodiment is shown in FIGS. 8 in which FIG. 8-1 shows the embodiment in a front view, FIG. 8-2 in a plan view and FIG. 8-3 is a side elevation.
In FIGS. 8-1 through 8 - 3 . the embodiment is shown in conjunction with the knife and method shown in FIGS. 1 to 3 with an additional double shoot extension 8 . Leading edge 16 of the lower portion 7 is extended further forward and downward as best depicted in FIG. 8-3 . As seen in the front view of FIG. 8-1 , this will provide a secondary furrow or ledge intermediate the surface of the soil 5 and the lower end 17 . FIGS. 8-1 through 8 - 3 show this embodiment as forming a v-shaped furrow particularly suited to the deposit of particulate material such as seed which would be retained in this groove. The extension 8 could have other shapes to form a ledge or other shape as required.
An extension 8 depends from the leading edge 16 and may be provided with a delivery conduit 19 .
This double shoot method forms a seed or other material positioning shelf or secondary furrow within the angled furrow with a specific spacing from the lowermost extremity.
An alternate embodiment of the invention is shown in FIGS. 4-6 . The knife 10 includes a blade 14 as described above. The knife 10 further includes an extension blade 30 that extends substantially horizontally form the blade 14 preferably at its lowermost end 17 . The extension blade 30 has a leading cutting edge 36 , which preferable forms a continuation of or a 3 rd part if also the leading ledge 16 . Edge 36 is substantially horizontal and is preferably oriented transverse to the direction of travel. The cutting edge 36 is formed between an upper surface 32 angled upwardly and rearwardly and a lower surface 33 which is substantially horizontal. The lower blade surface 33 may preferably be angled to the rear, upwardly about 2 degrees, or notched, to reduce drag.
The extension blade 30 increases the plain-width of the knife 10 as shown in FIG. 7 . This extends the cultivating and/or planting area for greater seed bed utilization, or may be selected for greater spacing between seed planting while still effectively cutting existing plant roots to condition more of the width of soil. The extension blade 30 may be varying width for different spacing considerations.
Outlets for seed, fertilizer and other addictives may be spaced apart in or on the extension blade 30 to form distinct rows (not shown) and are preferably adjacent the rear surface thereof or may provide for broadcast across the width of extension 30 .
Outlets 24 may also be placed at the corner between the angled blade 14 and the extension 30 as shown in FIGS. 4 and 5 , or higher on the angled blade 14 for vertical separation such as for herbicide application nearer the soil surface.
As seen in FIG. 7 , a plurality if knives shown including extension 30 on an implement frame in outline may be arranged spaced in continuous or overlapping arrangement on the implement 2 so that the full width of soil is conditioned. The number and spacing will depend on the crop and planting conditions. Suitable placement of outlets along extension 30 would result in a generally scattered seed and fertilizer delivery in behind each knife 10 . In this case the complete width of the soil may also be cut by the blade extension without being dragged and fouling the knife 10 .
The extension blade 30 may be positioned to travel under the path of the angled blade 14 of the adjacent knife 10 .
Knives 10 are mounted to an implement or cultivator frame 2 as in FIG. 7 . A wing section of the frame 2 is illustrated in outline form. Additional central and wing sections are not shown. The frame 2 is carried on loads bearing wheels (not shown) which support the frame 2 in a raised position for travel and in operative position.
Adjustment of the height if the frame 2 in a known fashion accurately controls furrow depth (d). Depths (d) may typically range from ½ inch to 4 inches or up to 6 inches. Alternatively, a ground following linkage may be used to attach each knife 10 to the frame 2 with the depth being controlled by a wheel attached to each knife assembly.
In uses the knifes 10 arranged in parallel fashion on an implement or overlapping arrangement on an angled draw bar are drawn by a tractor together with a seed carrier provided with reservoirs of seed and fertilizer material and a fluid delivery system operatively connected with the conduits 22 on the knives 10 . The frame 2 is advanced with the leading cutting edges 16 and optionally, edge 36 facing in the direction of travel 1 . The deposit of material is controlled by the speed of advance of the tractor in a known fashion.
The knife 10 will not normally produce overlapping furrows without the blade extension 30 being present, or being long enough to result in an overlapped cut with adjacent rows as the placement would be too close. Weed control with herbicides is necessary in those circumstances.
As seeding occurs, fertilizer can be added simultaneously in controlled concentration, or at a desired depth or spacing from the seed. Fertilizer is more efficiently used without loss from runoff. Further fertilizer is placed to be available to the crop and not at the surface for weeds. A substance delivery of fertilizer is particularly effective if gaseous fertilizer, such as ammonia, is used. The knife provides a variety of options for placement with minimum adjustment and cost.
It may be desired to seed an area progressively in time for continuous harvest. Or with different additives, or with different crop. Since the process is a complete single pass operation, each seeding will include complete weeding and fertilizing more accurately than if separate steps are made which might leave areas untouched.
The invention may also be used as a light tilling tool for minimum soil disturbance without seeding or fertilizer outlets. This would cut weeds and provide minimum soil aeration. The knife advantageously does not turn the soil which would incorporate weed seeds from the surface into the soil to germinate.
Additional embodiments of the present invention will be apparent to persons of skill in the art.
FIG. 9 is a plan-view diagram of an implement 120 which carries thirty-five angled-knife seeders 123 in four rows. The implement 120 has a centre section 124 , and two hinged wings 125 . The wings 125 can be folded upwards for road-transport and storage of the implement. The centre section 124 includes a hitching mechanism 126 whereby the implement can be towed by a tractor.
It will be noted that some of the angled-knife seeders 123 slope to the left, and some to the right. Thus, there is no, or only a small, net sideways force on the implement. The left seeders and the right seeders are kept separate. In banks, since the configuration of the seeders is not suitable for close-pitched left-right mountings thereof.
Press-wheels 127 are provided. One in-line behind each seeder. to roll over. And to close the ground. After the seeds have been deposited by the seeders.
The seeders are attached each to a respective mounting bar 128 , which is suspended from the frame 129 of the implement, the suspension mechanism including the usual break-back-spring mountings 130 .
FIG. 10 is front view of one of the angled-knife seeders 123 . FIG. 10 shows the seeder being dragged forwards, i.e. out of the paper, as indicated by the arrow 132 . FIG. 11 is a lateral or side elevation, showing the seeder being drawn through the ground, and moving to the left as indicated by arrow 132 . FIG. 11 includes an inset cross-section, taken on line +—+ of FIG. 10 , It is emphasized that line +—+ is vertical, i.e. the inset cross-section in FIG. 11 lies in a vertical plane.
As shown from the front view, FIG. 10 , the seeder or knife 123 has an angled blade 134 which extends down into the ground to a depth, typically of about 10 cm. The depth is determined by the needs of the type of seeds being planted; planting seeds deeper than 10 cm would be unusual, and 15 cm can be regarded as a maximum planting depth.
The angled knife cuts an angled slit-opening in the ground, and the seeds are deposited therein. The seeds to be planted are sullied from a hopper on the implement, and are blown along a hose by mechanism of a fan which forces an air flow in the hose. The hoses are of flexible plastic tubing, one for each seeder (the hoses are not shown in FIG. 9 ).
Each flexible hose is clipped to a respective conduit 135 , which is built into the seeder 123 . The conduit is structurally integrated into the back-side of the angled-knife-blade 134 , and runs down the back-side 136 of the blade. The conduit ends in a discharge mouth 137 , from which the seeds emerge, and fall down into the slit-opening. The discharge mouth 137 is near the bottom of the knife blade, whereby the seeds are deposited more or less at the bottom of the slit opening.
The conduit 135 is shown in the rear view of the seeder, FIG. 12 , and in the opposite side-elevational view to FIG. 11 , FIG. 13 . The upper end of the conduit terminates at a port 138 , into which the flexible hose can be secured.
The knife blade has an over-surface 139 and an under-surface 140 . These surfaces are respective pilat planes: which meet at a line, that line being the knife-edge 142 . The blade is generally triangular in cross-section. In that the surfaces 139 , 140 slope back from the knife edge, to a maximum thickness of the blade at the back-side 136 thereof. The conduit 135 is accommodated within the thickness of the back-side of the blade.
FIG. 14 is a cross-section of the blade 134 and shows the dimensions thereof. The FIG. 14 cross-section is taken in a plane at right angles to the knife-edge. The dimension 143 is the distance between the over-surface 139 and the under-surface 140 at the back-side if the blade, which in this case is 32 mm; and dimension 145 is the distance from the knife-edge 142 to the mid-point of the conduit 135 , which in this case is 70 mm. The conduit 135 has an internal diameter if 24 mm. The angle between the over-surface 139 and the under-surface 140 , in the cross-section at right-angles to the knife-edge, is called the wedge angle 146 , which in this case is 25 degrees.
Not only is the angled blade 134 angled to the side, at a side-slope-angle 147 , as shown in FIGS. 10 and 12 , but the blade is also given a forward pitch angle 148 , as shown in FIGS. 11 and 13 . In this case, the side-slope angle 147 is 45 degrees, and the forward pitch angle is also 45 degrees.
The leading knife-edge 142 is positioned such that when the blade is viewed from in front. Only the over-surface 139 can be seen. The under-surface 140 is invisible. That is to say, the knife edge is at the lowermost point of every vertical cross-section taken through the blade 134 . Thus, the portion of soil that lies in the path of the blade lies in the path of the over-surface 139 of the blade. The over-surface has the wedge angle 146 , and the soil is therefore driven upwards, by the wedge angle. The uplift travel of the soil is determined by the vertical height 149 of the over-surface 139 , as presented to the oncoming soil, which in this case is about 8 cm.
FIG. 15 is a front elevation of another design of angled-knife seeder 150 . In this case, the above-ground portion of the seed conduit 152 is positioned to one side of the above-ground shank 153 . This location of the conduit provides access for the nuts and bolts which are used at 154 to fix the seeder to the mounting bar 128 . However, although access for the nuts and bolts is good, the extra width of the shank 153 can be obtrusive, and can cause soil debris created by the passing of the angled blade to hang up such that the wide shank 153 can act like a bulldozer blade.
A deflector surface 156 is provided, for deflecting soil debris away from the front face of the shank 153 . The deflector surface 156 is angled to deflect the debris downwards, and to the side. The nubi 57 serves also to break the upward flow of the debris, and to keep the shank 153 clear.
It may be noted that in FIG. 1 , the triangular gusset-surface 159 was disposed at an angle that included a downwards component, and so the gusset-surface 159 also served to deflect up-flowing debris downwards, and sideways, away from the shank 12 of the knife. Thus, the deflector-surface can be on the outside ( FIG. 15 ) or the inside ( FIG. 1 ) of the angle between the shank and the blade. Providing downward-facing deflector surfaces on both the inside and the outside also is possible, except that the designer should take care that the knife is not weakened thereby, at the transition 160 ( FIG. 15 ), 162 ( FIG. 1 ), between the shank 12 and the angled blade 14 .
FIGS. 16 , 17 , 18 are other views of the knife of FIG. 15 . It will be noted that this knife includes a separable and replaceable tip 163 . The tip shown separately in FIG. 19 . FIG. 20 is a shaded view of the back of the body 164 of the knife, and shows not only how the conduit in this design is molded into the shape of the knife, but shows also a spline 165 on the body, which forms the mounting base for the replaceable tip 163 . The tip 163 is held to the spline 165 by mechanism of a pin which engages the pin-receiving-hole 167 . The spline 165 is prism-shaped, having a triangular cross-section like that of the blade itself, but smaller, and the tip 163 includes a socket that is complementary to the conduit 152 . Once pinned in place, the tip 163 is very securely constrained against all modes of movement relative to the body 164 . The pin serves only to keep the tip from falling down the spline, but the force tending to make the tip 163 move in that mode minimal: all the heavy forces between the tip 163 and the body 164 are supported by the chunky spline 165 .
The conduit 152 continues inside the spline 165 . It is important that the seeds are deposited close to the bottom of the cut opening; with the conduit inside the spline, even though the bottom part of the knife comprises the tip, the conduit goes to the bottom of the opening. (It would be inefficient to cut the opening deeper that the planting depths of the seed, so the discharge mouth of the conduit should be as near the bottom of the knife as possible.) On the other hand, the prudent designer would seek to avoid calling for the manufacture of a (tubular) extension of the conduit in the tip casting. Putting the conduit in the spline puts the discharge mouth of the conduit more or less at the bottom of the trench, even though the knife has a replaceable tip.
It will be noted that the lower extremity 168 of the knife edge 169 on the body 164 is rounded convexly, whereas the upper extremity 172 of the knife edge 170 on the tip 163 includes a tag 173 which is rounded concavely. Thus, debris traveling up the knife edge can readily pass smoothly over the transition between the two knife edges 169 , 170 . The designer should see to it that the knife edges do not contain interruptions, upon which soil-debris could be snagged. Forming the body 164 with a large convex radius is easy from the casting-manufacture standpoint; it is much easier to control the quality of a concavely-curved tag on the tip casting than on the body casting.
The knife edge 170 in the tip 163 can be blunter than the knife edge 169 on the body 164 . The tip 163 operated more deeply, where debris, even if imperfectly cut, tends to be brushed off the knife edge 170 by the pressing passing soil. On the body 164 , the knife edge 169 itself has to do all the cutting of debris and vegetation, with little assistance from the passing soil, since, being shallower, the passing soil might more easily be deflected. It is noted that, if it happened, a hang-up of imperfectly cut material on the knife edge would be a quite serious problem, as it would quickly lead to disruption and disturbance of a large area of soil around the slit opening.
Conventionally, when seeding has been done with seeding knives (as opposed to discs, etc) the seeding knife has been held vertically. When the seeding knife is held at a side-slope-angle, as described herein, the manner in which the soil is opened for receiving the seeds is considerably changed.
When the knife is at a side-slope-angle of about 45 degrees to the horizontal, what happens is that a flap 174 of soil is lifted temporarily by the passing blade 134 , and then the flap is lowered gently back after the seeder knife 123 has passed. As a result, the layers of the soil are preserved, during seeding. In other words, it is possible for a farmer to plant seed without disturbing the stratification of the soil. It may be noted that the press wheels 127 serve to press the flap 174 back down, and assist in the maintenance of stratification: thus the function of the press wheel is more in harmony with the action of the angled blade, than in the case of a press when linked with, for example, a non-angled (vertical) seeding knife.
Maintenance of soil stratification is important in currently-favored minimum-till farming regimes, because moisture in the layers a few centimeters down is not dissipated; weed seeds on the surface remain on the surface and do not germinate; and stalks and vegetation at the surface remain intact, providing cover and moisture retention. On the other hand, the angled knife, especially when a wing extension is provided below ground, cuts and severs the roots of any vegetation that might be present, whereby weeds and unwanted plant growth are destroyed simply by mechanical action. Using herbicide to destroy weeds is expensive and can be dangerous, and has to be done as “reach” of the angled knife can be enough to sever the roots of weeds and other growth not only around the seed openings, but over the whole area of ground between the openings.
The fact that the flap of soil is pushed upwards by the angled blade does not mean that the soil is compressed: if the soil were pushed downwards or sideways, it would become compressed and perhaps smeared, since there is no where for the deflected soil to go; but when the soil is urged upwards, the soil simply moves upwards. Of course, lifting deeper soild would involve lifting the weight of all the soil above, so lifting without compression only works down to shallow depths. Thus, it would not be possible to lift a flap of soil without compressing it if the soil were more than 10 or 15 cm deep. But it is recognized that seed planting is done predominantly at shallower depths than that; and it is recognized that the depths down to which an angled blade can cause the soil to simply lift without being compressed is a suitable depth to enable planting of nearly all types of seeds.
If the knife were nearly vertical, i.e. if the knife were angled over at more than about 60 degrees to the horizontal, the lifting action that occurs with the angled knife would become negligible. With the 45-degree angle, most of the movement of the soil that occurs is a riding up of the soil over the front edge of the knife. At an angle of 60 degrees, the soil tends to be bulldozed, or chiseled, rather than slit or cut. Insofar as the soil is pushed to the side by the knife, the soil is compressed, and smeared, rather than gently lifted.
Of course, the knife must emerge from the ground surface, and the very shallow soil around the point of emergence inevitably is lifted too much, and tends to fly away. However, this effect is less disturbing than inserting a vertical chisel into the ground.
If the knife were more nearly horizontal, this fly-away lifting of the shallow soil might be too much. Besides, if the knife were nearly horizontal, although the knife would still lift the flap of soil, the knife blade would need to be too long in order to get down to the seed planting depth, which would mean that too much soil was being moved for a given planting depth, and which would be poor mechanically.
Tests have shown that the slap-lifting, stratification-maintaining, advantageous effects of the angles blade are largely lost if the blade is angled (i.e. the side-slope-angle) more than about 55 degrees or less than about 35 degrees. 60 degrees and 30 degrees can be regarded as the practical limits. It has been found that the force required to draw the angles blade through the ground is at a minimum when the blade is at about 45 degrees. It may be noted that the minimum draw force is an indication of minimum ground disturbance, which is what makes for minimum-till agriculture.
The leading knife-edge of the angled blade should be lowermost into the ground. That is to say, the soil approaching the blade should “see” only the over-surface of the blade. Thus, all the soil that is deflected is deflected upwards. If some of the soil were driven downwards, or horizontally sideways, it would be compressed or smeared, and seeding is most effective and efficient when the seeds are placed on and in soil that has not just been compressed.
The effective but gentle lifting as desired has been obtained with angled blades where the blade has been so presented that the over-surface has been about 7 cm high, measured in a vertical sense, from the leading knife edge to the back of the over surface. (The thickness of the blade, measured in a plane at right angled to the leading edge, preferably is between 25 and 45 mm.) The angle between the over-surface of the blade and the under-surface, called the wedge angle, is a key factor in determining the lift of the blade, and good results have been obtained when the wedge angle lies between 20 and 30 degrees.
Preferably, the over-surface should be a single flat plane over its whole area, but it is recognized that it id the front of the over-surface of the blade that is key to the performance, i.e. the front 4 cm of the over-surface contiguous with the knife edge.
Preferably, the blade is generally triangular as to its cross-sectional shape, the three sides of the triangle being the over-surface, the under-surface, and the back-side of the blade. (The back-side is not, as shown, a flat plane.) It is recognized that the triangular is a good shape, in that it leads to a suitable angle for the over-surface of the blade, in order for the over-surface to deflect soil dynamically; also, the bottom face can be easily set to not touch the soil passing-by underneath the blade; also, the bottom face can easily be set to not touch the soil passing-by underneath the blade; also, the thick back-side has to be thick to accommodate the conduit. In short, the triangular shape is a highly efficient shape for performing the soil-moving operations required for seeding, for accommodating the seed conduit, and (not least) is a food shape for providing mechanical strength and rigidity in just the right amounts for the task.
The designer should see to it that the knife is reasonably short, in the travel direction. Length would just lead to extra drag, and perhaps smearing of the soil, the aim should be to combine efficient use of surfaces and angles to give smooth lift-then-fall-back movement of the soil, without disturbing the soil, and while maintaining stratification. The designer should see to it that the surfaces are angled enough, and are long enough for that, and of course the knife has to be strong and rigid enough to be struck occasionally by stones etc without being damaged. It is recognized that the angled blasé as described herein is a design that handles these conflicting requirements very advantageously.
The conduit preferably should be in the size range of 15 to 25 mm diameter, for proper seed conveyance. It is recognized that such a size of conduit is wee-suited to being located behind the triangular angled blade, as described. The blade surfaces, i.e. the over-surface and the under-surface, slope towards the conduit as two simple flat planes, straight from the knife edge.
As mentioned, the functions of the blade require that the blade be wide enough for its surfaces to be so angled as to be effective; and the blade must also be strong enough; beyond that, the blade should preferably be short. Good results have been obtained when the blade is about 7 cm, or at least between 5 cm and 10 cm, in width, from the knife-edge to a mid-point inside the conduit.
The blade should have forward pitch to ensure the soil debris can clear, by riding upwards along the knife edge, and out of the soil. It will happen sometimes that some material are not cut, or not cut immediately, by the knife edge, and will be piled up ahead of the knife edge, thereby blunting the knife edge. The angled knife should have forward pitch to counteract this. Of course, conventional vertical seeding knives have had forward pitch.
Preferably, the seed conduit should be integral with the knife unit. If separate, the conduit has to be attached to the knife unit. The conduit should not get in the way, not least above ground, where the conduit can contribute to snagging of soil debris. Therefore, the conduit should lie in line behind the knife. Whilst this is clearly achievable below the ground, above ground putting the conduit in line with the knife structure is not so good, because the shank of the knife is attached to the mounting bar by bolts passing through from front to back, and putting the conduit behind the shank would deny access to the bolts/nuts.
The designer also want the point of attachment of the flexible seed hose to be high, out of harm's way, and also wants to provide room for a clip for attaching the hose into the conduit. The designer either can put the conduit on a stalk that protrudes out behind the shank (which suits fabricated construction (FIG. 2 )), or can put the conduit to one side of the shank (which suits casting ( FIG. 16 )). Or, the conduit may be finished lower down, below where the shank is bolted to the mounting bar ( FIG. 11 ), although now the flexible hose might be vulnerably close to the ground. Putting the conduit to one side of the shank ( FIG. 16 ) gives access to the fixing bolts, but now the front face of shank is thereby widened, so it is even more important to take measures against snagging of the above-ground soil debris on the shank.
One of the benefits of the angles blade configuration lies in the ability to deposit two types of items simultaneously, e.g. seeds and fertilizer, which preferably should be kept spaced apart, upon planting. Simultaneous deposition of both seeds and fertilizer ( FIGS. 8 ) is simplified by the fact that the knife is at an angle, while ensuring same are kept spaced apart. If the knife were vertical, both items would fall to the bottom of the trench, and it would be difficult to keep the items apart. On vertical knife seeders, it is conventional to provide side ledges; for fertilizer, however, the protrusions on the vertical knifes that produce such side ledges have also compressed the soil.
Generally, the farmer wishes to plant as many rows of seeds as possible in a single pass if the seeder implement. In one of the machines described herein, thirty-five seeders are provided on a single implement. The smallest number that might practically be contemplated would be about eighteen seeders per implement. The large number of seeders is appropriate for single-pass seeding operations at shallow depth, in that a tractor can easily provide the force necessary to draw a large number of shallow seeders through the ground. This may be contrasted with the conventional usage of angled cutters to break up hard-pan sub-soil, i.e. caked clay and soil some 50 cm or more below ground. Sometimes, these deep angled-cutters have been used to prepare ground for seeding, but in that case the seeding has been done separately, as a follow-up seeding operation, using conventional seed drills. (Breaking up hard-pan also can be done for other purposes, e.g. to improve drainage.) The conventional large, deep, hard-pan angled-cutters were angled simply in order to cover more ground. They were constructed so as to cause maximum disturbance to the soil, at a large depth; they required large forces to draw them through the ground, so that only a small number, say four to five, could be pulled by a tractor. The use of an angled blade as described herein to lift shallow flaps of soil with minimum disruption, and to lower the soil flap back down without disturbing stratification, makes a clear contrast with the use of deep angled cutters to break up hard-pan. It is emphasized that the gentle, minimum-till, operations described can take place only at shallow depths.
In the above aspects, the invention is defined by reference to an implement, in which the angled blades are mounted for operation, In another aspect, the invention can be defined with respect only to the knife unit itself, independently of the implement. In this case, the definition makes use of the shank of the knife, and of the axis of the shank. When the shank is provided with two bolts, one above the other, for attachment to the mounting bar, the shank axis (in a frontal view of the shank) is the line that runs through the bolts. However, even if the shank is mounted by mechanism other than two bolts vertically in-line, the shank still has an axis, which can be determined by the geometry of the shank in a particular case. The major features of the invention, the blade lies at an angle to the shank in front view, and the shallow depth of the blade, are present in this definition.
As mentioned above, sometimes the conventional vertical knife seeders have included, as an accessory, a mechanism for providing a side ledge to the vertical trench. As mentioned, grains of fertilizer are deposited on or in this side ledge, whereby the fertilizer can be kept spaced apart from the seeds. The fertilizer rests on the ledge, while the seeds fall down to the bottom of the vertical trench.
An example of such vertical-knife-with-side-ledge structure is depicted in Canadian patent publication CA-2,099,555 (Henry, 1995). Henry's structure includes a first conventional vertical knife-blade, for cutting a vertical slit in the ground, with the associated delivery pipe for depositing seeds at the bottom of the vertical slit. Henry also shows a ledge-cutting accessory. The accessory is fixed to the back of the vertical knife-blade. Thus, in the design of Henry, two injectors are shown: one for injecting seeds, and the other for injecting fertilizer.
Regarding Henry's vertical knife-blade cutter/fertilizer-injector: when viewed from the side, Henry's knife blade is angled, such that the bottom extremity of the knife-blade leads the rest of the knife-blade as the knife-blade travels through the ground. It is conventional, and very common, for vertical seeding-trench knife-blades to be angled forwards, i.e. bottom-edge leading. In the front view, Henry's knife-blade is not angled at all.
Regarding Henry's side-ledge cutter/fertilizer-injector: when viewed from the side Henry's ledge-cutter is so angled as to be “bottom-edge-trailing”. That is to say, the bottom extremity of the ledge-cutter lags, or trails, as the ledge-cutter travels through the ground. In the front view, Henry's ledge-cutter makes an angle to the horizontal of about 45 degrees.
Neither of the blades or cutters of Henry will achieve the “gentle up-and-over” effect, which is the aim of the present invention. This is because neither of the blades or cutters of Henry has an over-surface and an under-surface, which meet at a line, where the line defines the leading knife edge of the blade, and where the knife edge, thus defined, has a side-slope angle of between 30 degrees and 60 degrees.
Defined with the respect only to the knife unit itself, independently of the implement. In this case, the definition makes use of the shank of the knife, and of the axis of the shank. When the shank is provided with two bolts, one above the other, for attachment to the mounting bar, the shank axis (in a frontal view of the shank) is the line that runs through the bolts. However, even if the shank is mounted by mechanism other than two bolts vertically in-line, the shank still has an axis, which can be determined by the geometry of the shank in a particular case. The major features of the invention, that the blade lies at an angle to the shank in front view, and the shallow depth of the blade, are present in this definition. | The present invention relates to a knife for and a method of zero till or minimum till seeding and fertilizing. The knife is particularly adapted for dry land conditions producing minimum solid disturbance and very shallow operation. The knife has a high penetration angle preferably of 45 degrees which permits the blade to enter high trash surface cover with little tendency to plug due to trash accumulation. The blade has a forward angle of attack, the lower cutting edge advancing before the upper cutting edge, serving to make a clean cut in the soil surface without accumulating trash. Seed and/or fertilizer conduits are attached to or incorporated in the trailing face of the blade in which the outlets may be spaced for controlled placement of the materials. By the method a furrow is cut having a substantial transverse component in an operation with a substantial forward component. A preferred embodiment includes a horizontal extension blade for cutting a horizontal swath at a shallow depth through weed growth. Conduits may be secured to the extension to allow greater separation and control of material placement. The knives may be arranged in overlapping configuration on the draw bar to affect weed cutting, seeding and fertilizing of a complete with of soil in a single pass. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of U.S. patent application Ser. No. 10/829,443 filed on Apr. 22, 2004 (now U.S. Pat. No. 7,001,942 B2), which in turn is based on, and claims domestic priority benefits under 35 USC §119(e) from, U.S. Provisional Application Ser. No. 60/466,424 filed on Apr. 30, 2003, the entire content of each being expressly incorporated hereinto by reference.
FIELD OF THE INVENTION
The present invention relates generally to flame retardant materials and methods. In especially preferred embodiments, the present invention relates to flame retardant materials and methods which employ a flame-retardant superabsorbent polymer (SAP).
BACKGROUND AND SUMMARY OF THE INVENTION
Fiberglass-reinforced plastics (FRP) composites are finding increased usage in a variety of end-use applications. For examples, FRP composites are increasingly being used in ships, especially Naval ships, as load-bearing structures, such as light weight foundations, deckhouses and masts. 1 Industrial uses for FRP composites include piping, valves, centrifugal pumps, heat exchangers as well as gratings, screens and ventilation ducts. Such increased usage is being driven by a number of market needs, for example, so as to reduce maintenance, lower weight, increase covertness (especially for Naval warships) and decrease costs. FRP composites must however be sufficiently fire resistant so that the composite is not a source of spontaneous combustion and will not contribute to the rapid spread of fire. Generally, flame retardants are incorporated in a FRP composite to achieve the desired flame resistance. 1 U. Sorathia, J. Ness, M. Blum, “Fire safety of composites in the US Navy”, Composites: Part A, 30, 707-713 (1999).
Flame retardants interfere with burning by acting either through the vapor phase or the condensed phase by chemical and/or physical mechanisms. Some common types of flame retardants and mechanisms of action include: 2 2 Lu et al, “Recent developments in the chemistry of halogen-free flame retardant polymers”, Prog Polym Sci, 27, 1661-1712 (2002).
Fillers—act to dilute the polymer and reduce concentration of decomposition gases; Hydrated fillers—release non-flammable gases or decompose endothermically to cool the pyrolysis zone at the combustion surface; Halogen, phosphorus and antimony—act in vapor phase by a radical mechanism to interrupt the exothermic processes and to suppress combustion; Phosphorus—also acts in the condensed phase promoting char formation acting as a barrier to inhibit gaseous products from diffusing to the flame and shields the polymer from heat and air; and Intumescent materials—materials swell when exposed to fire or heat to form a porous foamed mass acting as a barrier to heat, air and pyrolysis products.
In FRP composite materials, fillers and halogenated resins are the most common methods used to achieve flame resistance. Fillers such as aluminum trihydrate release water upon heating. However, such fillers have to be incorporated in high amounts and have a negative effect on mechanical properties. Halogenated resins have clear disadvantages, particularly, the toxicity of hydrogen halide formed during combustion. 3 Toxic fumes released during the combustion of halogenated resins can be lethal in the confined spaces found in aircraft fuselages or marine hull compartments. 3 Id.
Flame retardants can be incorporated into polymeric materials either as additives or as reactive materials. Additive type flame retardants are widely used by blending with polymeric materials. In FRP resins, the flame retardant additive is added to the resin prior to fiber impregnation. Additives present problems including poor compatibility, leaching and reduced mechanical properties. Reactive flame retardants are an attempt to overcome the problems of additives through copolymerization of the flame retardant with the polymer. Copolymerized flame retardants are designed not to leach or reduce mechanical properties. At this time, most copolymerized flame retardants are based on halogenated monomers with the aforementioned problems of toxicity.
Recently, in U.S. Pat. No. 6,290,887 to Sheu et al (the entire content of which is expressly incorporated hereinto by reference), superabsorbent polymer (SAP) particles pre-loaded with moisture have been incorporated into a thermoplastic polymer (e.g., polyethylene) so as to obtain a SAP-enriched plastics material that may be extruded into desired shapes (e.g., as an outer jacket of a telecommunications cable).
It would therefore be desirable if flame-retardant SAP could be incorporated in curable thermoset resins without adversely affecting the resin curing process. It would especially be desirable if such flame-retardant SAP could be reacted with curable thermoset resins during the curing process so that, when cured, the SAP would be chemically bound (linked) to the polymeric chain of the resulting cured thermoset resin. In such a manner, improvements to flame retardant properties as well as improvements to other mechanical/physical properties (e.g., impact resistance) could be “engineered” into FRP composites formed of such thermoset resins. It is towards fulfilling such needs that the present invention is directed.
Broadly, the present invention is embodied in products and processes whereby flame-retardant SAP particles are incorporated into synthetic resins, especially curable thermosettable resins. The SAP particles are most preferably hydrated with an aqueous flame-retardant solution. In this regard, the flame-retardant solution may consist essentially of water alone or a water solution containing one or more water soluble inorganic flame retardants.
When SAP particles are hydrated with an aqueous inorganic flame retardant solution, the SAP particles may thereafter be dried to remove substantially the water component. In such a manner, the inorganic flame retardant will remain as a dried residue physically entrained within the SAP particles. As such, the SAP particles serve as a physical matrix in which the inorganic flame retardant is homogenously dispersed. The SAP particles may then be blended with a synthetic resin as is or alternatively may be ground into more finely divided particles which contain the dried residue of the aqueous inorganic flame retardant solution and then blended with a suitable synthetic resin.
It has been found that, when incorporated into a curable thermoset resin and cured, the fame-retardant SAP particles do not affect the curing process of the thermoset resin. The SAP particles may also be modified so as to include one or more pendant reactive groups which serve to react with the thermoset resin during the curing process so as to be chemically bound (linked) thereto.
These and other aspects and advantages will become more apparent after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.
DETAILED DESCRIPTION OF THE INVENTION
Superabsorbent polymers (SAPs) are in and of themselves well known and have the ability to absorb many times their weight in water. Virtually any SAP may be employed in the practice of the present invention. For example, SAP as disclosed in U.S. Pat. Nos. 5,461,085; 5,525,703; 5,612,384 and/or 5,669,894 (the entire contents of each patent being incorporated expressly hereinto by reference) may be employed. SAPs are available commercially in a variety of chemical forms, including substituted and unsubstituted natural and synthetic polymers, such as hydrolysis products of starch acrylonitrile graft polymers, carboxymethylcellulose, cross-linked polyacrylates, sulfonated polystyrenes, hydrolyzed polyacrylamides, polyvinyl alcohols, polyethylene oxides, polyvinylpyrrolidones, polyacrylonitriles and the like.
SAP is typically provided in the form of particles. As used herein, the term “SAP particles” and like terms mean granules, fibers, flakes, spheres, powders, platelets, and/or other solid shapes and forms known to those skilled in the SAP art. SAP particles having a nominal particle size of less than about 100 microns (e.g., between about 0.20 micron to about 50 microns, and more preferably between about 0.50 micron to about 10 microns), to up to about 500 microns (e.g., between about 100 to about 500 microns) may be employed in the practice of the present invention. As used herein, the term “nominal particle size” means the size of a particle capable of passing through a screen of a stated mesh size. The SAP particles may be ground to a more finely divided particulate form so as to achieve the desired nominal particle size. For example, dried SAP particles containing the residue of a water-soluble inorganic flame retardant may first be ground to a nominal particle size of about 300 microns or less prior to being blended with a thermoset resin in a flame-retarding effective amount.
The SAP particles employed in the practice of the present invention are most preferably hydrated. By the term “hydrated SAP particles” is meant that the SAP particles are in a hydrated state in that the SAP particles have absorbed at least 5% of their own weight, and usually several times their weight, in water. Conversely, the term “dried SAP particles” is meant to refer to SAP particles that have previously been hydrated, but which have subsequently been dried to a water absorption content of less than 5%, and typically less than 3%, of the their own weight.
The SAP particles may be hydrated with an aqueous solution containing one or more inorganic flame retardants. Most preferably, the inorganic flame retardants are water-soluble so that they may be dissolved in water to form an aqueous inorganic flame retardant solution that may then be absorbed by the SAP particles. Once absorbed, the SAP particles may be dried to remove the water thereby leaving the inorganic flame retardant physically within the SAP particles as a dried residue of the aqueous inorganic flame retardant solution. By the term “dried residue” is meant that the solute (e.g., the inorganic flame retardant) remains physically following evaporation or removal of water. By the term “water soluble” is meant that at least about 1 g of solute per 100 cc of water, more preferably at least about 10 g of solute per 100 cc of water, dissolves.
Specific examples of water-soluble inorganic flame retardants that may be employed in the practice of the present invention include boric acid (ortho and tetra), sodium tetraborate and hydrate, sodium metaborate and hydrates, zinc borate, phosphoric acid and sodium salt derivatives thereof, phosphorous acid and sodium salt derivatives thereof, ammonium orthophosphate, ammonium hypophosphate, ammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium hypophosphite, ammonium dihydrogen orthophosphite, ammonium sulfamate, ammonium bromide, ammonium sulfate, and sodium tungstate. Most preferably, the inorganic flame retardant is present in the SAP particles in an amount of between about 1 to about 500 wt. %, more preferably between about 25 wt. % to about 200 wt. %, based on the total weight of the flame-retardant SAP particles.
The SAP may be modified so as to include one or more pendant reactive groups which serve as sites to react with, and be chemically bound (linked) to, the curable thermoset resin during the curing process. The pendant reactive groups of the modified SAP may be virtually any group or groups capable of reacting with functional groups present in a thermosetting resin. Examples of the reactive groups provided with modified SAP in accordance with the present invention include, for example, acrylics, methacrylics, styryls, epoxies (oxirane), isocyanates, aromatic alcohols, thiols, carboxylic acids, hydroxyls, amines, and like groups.
Examples of thermosetting resins include acrylics, urethanes, unsaturated polyesters, vinyl esters, epoxies, phenol/formaldehyde resins, urea/formaldehyde resins and melamine/formaldehyde resins; crosslinkable acrylic resins derived from substituted acrylates such as epoxy acrylates, hydroxy acrylates, isocyanato acrylates, urethane acrylates or polyester acrylates; alkyd resins, polyester resins and acrylate resins crosslinked with melamine resins, urea resins, isocyanates, isocyanurates, carbamates or epoxy resins
Suitable unsaturated polyester resins include practically any esterification product of a polybasic organic acid or anhydride and a polyhydric alcohol, wherein either the acid or the alcohol, or both, provide the reactive ethylenic unsaturation. Typical unsaturated polyesters are those thermosetting resins made from the esterification of a polyhydric alcohol with an ethylenically unsaturated polycarboxylic acid. Examples of useful ethylenically unsaturated polycarboxylic acids include maleic acid, fumaric acid, itaconic acid, dihydromuconic acid and halo and alkyl derivatives of such acids and anhydrides, and mixtures thereof. Exemplary polyhydric alcohols include saturated polyhydric alcohols such as ethylene glycol, 1,3-propanediol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2-ethylbutane-1,4-diol, octanediol, 1,4-cyclohexanediol, 1,4-dimethylolcyclohexane, 2,2-diethylpropane-1,3-diol, 2,2-diethylbutane-1,3-diol, 3-methylpentane-1,4-diol, 2,2-dimethylpropane-1,3-diol, 4,5-nonanediol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerol, pentaerythritol, erythritol, sorbitol, mannitol, 1,1,1-trimethylolpropane, trimethylolethane, hydrogenated bisphenol-A and the reaction products of bisphenol-A with ethylene or propylene oxide.
The resin can be formed by the addition of recycled polyethylene terephthalate (PET), such as from soda bottles to the base resin prior to polymerization. PET bottles can be ground and depolymerized in the presence of a glycol, which produces an oligomer. The oligomer can then be added to a polymerization mixture containing polyester monomer and polymerized with such monomer to an unsaturated polyester.
Unsaturated polyester resins can also be derived from the esterification of saturated polycarboxylic acid or anhydride with an unsaturated polyhydric alcohol. Exemplary saturated polycarboxylic acids include oxalic acid, malonic acid, succinic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, hydroxylsuccinic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, 2,2-dimethylglutaric acid, 3,3-dimethylglutaric acid, 3,3-diethylglutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, tetrabromophthalic acid, tetrahydrophthalic acid, 1,2-hexahydrophthalic acid, 1,3-hexahydrophthalic acid, 1,4-hexahydrophthalic acid, 1,1-cyclobutanedicarboxylic acid and trans-1,4-cyclohexanedicarboxylic acid.
Unsaturated polyhydric alcohols which are suitable for reacting with the saturated polycarboxylic acids include ethylenic unsaturation-containing analogs of the above saturated alcohols (e.g., 2-butene-1,4-diol).
Suitable vinyl ester resins include practically any reaction product of an unsaturated polycarboxylic acid or anhydride with an epoxy resin. Exemplary acids and anhydrides include (meth)acrylic acid or anhydride, α-phenylacrylic acid, α-chloroacrylic acid, crotonic acid, mono-methyl and mono-ethyl esters of maleic acid or fumaric acid, vinyl acetic acid, cinnamic acid, and the like. Epoxy resins which are useful in the preparation of the polyvinyl ester are well known and commercially available. Exemplary epoxies include virtually any reaction product of a polyfunctional halohydrin, such as epichlorohydrin, with a phenol or polyhydric phenol. Suitable phenols or polyhydric phenols include for example, resorcinol, tetraphenol ethane, and various bisphenols such as bisphenol-A, 4,4′-dihydroxydiphenyl-sulfone, 4,4′-dihydroxy biphenyl, 4,4′-dihydroxydi-phenylmethane, 2,2′-dihydroxydiphenyloxide, and the like.
Typically, the unsaturated polyester or vinyl ester resin material also includes a vinyl monomer in which the thermosetting resin is solubilized. Suitable vinyl monomers include styrene, vinyl toluene, methyl methacrylate, p-methyl styrene, divinyl benzene, diallyl phthalate and the like. Styrene is the preferred vinyl monomer for solubilizing unsaturated polyester or vinyl ester resins.
Suitable phenolic resins include practically any reaction product of a aromatic alcohol with an aldehyde. Exemplary aromatic alcohols include phenol, orthocresol, metacresol, paracresol, Bisphenol A, p-phenylphenol, p-tert-butylphenol, p-tert-amylphenol, p-tert-octylphenol and p-nonylphenol. Exemplary aldehydes include formaldehyde, acetaldehyde, propionaldehyde, phenylacetaldehyde, and benzaldehyde. Particularly preferred are the phenolic resins prepared by the reaction of phenol with formaldehyde.
The resin may comprise an epoxy resin, i.e., one that contains at least one oxirane group in the molecule. Hydroxyl substituent groups can also be present and frequently are, as well as ether groups. Halogen substituents may also be present. Generally, the epoxy resins can be broadly categorized as being aliphatic, aromatic, cyclic, acyclic, alicylic or heterocyclic. Preferably aromatic epoxide resins are used. One particularly preferred group of aromatic epoxy resins are the polyglycidyl ethers of polyhydric aromatic alcohols, such as, for example, dihydric phenols. Suitable examples of dihydric phenols include resorcinol, catechol, hydroquinone, bis(4-hydroxyphenyl)-1,1-isobutane; 4,4-dihydroxybenzophenone; bis(4-hydroxyphenyl)-1,1-ethane; bis(2-hydroxynaphenyl)methane; 1,5-hydroxynaphthalene and 4,4′-isopropylidenediphenol, i.e., bisphenol A. Of the many epoxy compounds that may be utilized to synthesize the epoxy resins, the one principally utilized is epichlorohydrin, although epibromohydrin is also useful. The polyglycidyl ethers are obtained by reacting epichlorohydrin and bisphenol A in the presence of an alkali such as sodium or potassium hydroxide. The series of epoxy resins sold by Shell Chemical Company under the trademark EPON are useful. Another group of useful epoxy resins are the polyglycidyl ethers derived from such polyhydric alcohols as ethylene glycol; diethylene glycol; triethylene glycol; 1,2-propylene glycol; 1,4-butylene glycol; 1,5-pentanediol; 1,2,6-hexanetriol; glycerol and trimethylolpropane. Also useful are the epoxide resins that are polyglycidyl ethers of polycarboxylic acids. These materials are produced by the reaction of an epoxy compound such as epichlorohydrin with an aliphatic or aromatic polycarboxylic acid such as oxalic acid; succinic acid; glutaric acid; terephthalic acid; 2,6-napthalene dicarboxylic acid and dimerized linoleic acid. Still another group of epoxide resins are derived from the epoxidation of an olefinically unsaturated alicyclic material. Among these are the epoxy alicyclic ethers and esters well known in the art.
Epoxy resins also include those containing oxyalkylene groups. Such groups can be pendant from the backbone of the epoxide resin or they can be included as part of the backbone. The proportion of oxyalkylene groups in the epoxy resin depends upon a number of factors, such as the size of the oxyalkylene group and the nature of the epoxy resin.
One additional class of epoxy resins encompasses the epoxy novolac resins. These resins are prepared by reacting an epihalohydrin with the condensation product of an aldehyde with a monohydric or polyhydric phenol. One example is the reaction product of epichlorohydrin with a phenolformaldehyde condensate. A mixture of epoxy resins can also be used herein.
The epoxy resins require the addition of a curing agent in order to convert them to thermoset materials. In general, the curing agents which can be utilized herein can be selected from a variety of conventionally known materials, for example, amine type, including aliphatic and aromatic amines, and poly(amine-amides). Examples of these include diethylene triamine; 3,3-amino bis propylamine; triethylene tetraamine; tetraethylene pentamine; m-xylylenediamine; and the reaction product of an amine and an aliphatic fatty acid such as the series of materials sold by Henkel Corporation under the name VERSAMID. Preferably the poly(amine-amide) materials such as VERSAMID or its equivalent are utilized.
Also suitable as curing agents for epoxies are polycarboxylic acids and polycarboxylic acid anhydrides. Examples of polycarboxylic acids include di-, tri-, and higher carboxylic acids such as, for example, oxalic acid, phthalic acid, terephthalic acid, succinic acid, alkyl and alkenyl-substituted succinic acids, tartaric acid, and polymerized fatty acids. Examples of suitable polycarboxylic acid anhydrides include, among others, pyromellitic anhydride, trimellitic anhydride, phthalic anhydride, succinic anhydride, and maleic anhydride. In addition, aldehyde condensation products such as urea-, melamine-, or phenol-formaldehyde are useful curing agents. Other suitable curing agents include boron trihalide and complexes of boron trihalide with amines, ethers, phenols and the like; polymercaptans; polyphenols; metal salts such as aluminum chloride, zinc chloride and magnesium perchlorate; inorganic acids and partial esters such as phosphoric acid and n-butyl orthophosphite. It should be understood that blocked or latent curing agents can also be utilized if desired; for example, ketimines that are prepared from a polyamine and a ketone.
The amount of the epoxy resin and curing agent utilized can vary, but generally the equivalent ratio of epoxy to amine is within the range of from 0.05:1 to 10:1. Preferably, the epoxy to amine equivalent ratio is within the range of from 0.1:1 to 1:1, and more preferably within the range of 0.3:1 to 0.9:1.
The pendant reactive groups of the modified SAP may be virtually any group or groups capable of reacting with functional groups present in a thermosetting resin. Examples of the reactive groups provided with modified SAP in accordance with the present invention include, for example, acrylics, methacrylics, styryls, epoxies (oxirane), isocyanates, aromatic alcohols, thiols, carboxylic acids, hydroxyls, amines, and like groups.
Examples of thermosetting resins include acrylics, urethanes, unsaturated polyesters, vinyl esters, epoxies, phenol/formaldehyde resins, urea/formaldehyde resins and melamine/formaldehyde resins; crosslinkable acrylic resins derived from substituted acrylates such as epoxy acrylates, hydroxy acrylates, isocyanato acrylates, urethane acrylates or polyester acrylates; alkyd resins, polyester resins and acrylate resins crosslinked with melamine resins, urea resins, isocyanates, isocyanurates, carbamates or epoxy resins
Suitable unsaturated polyester resins include practically any esterification product of a polybasic organic acid or anhydride and a polyhydric alcohol, wherein either the acid or the alcohol, or both, provide the reactive ethylenic unsaturation. Typical unsaturated polyesters are those thermosetting resins made from the esterification of a polyhydric alcohol with an ethylenically unsaturated polycarboxylic acid. Examples of useful ethylenically unsaturated polycarboxylic acids include maleic acid, fumaric acid, itaconic acid, dihydromuconic acid and halo and alkyl derivatives of such acids and anhydrides, and mixtures thereof. Exemplary polyhydric alcohols include saturated polyhydric alcohols such as ethylene glycol, 1,3-propanediol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2-ethylbutane-1,4-diol, octanediol, 1,4-cyclohexanediol, 1,4-dimethylolcyclohexane, 2,2-diethylpropane-1,3-diol, 2,2-diethylbutane-1,3-diol, 3-methylpentane-1,4-diol, 2,2-dimethylpropane-1,3-diol, 4,5-nonanediol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerol, pentaerythritol, erythritol, sorbitol, mannitol, 1,1,1-trimethylolpropane, trimethylolethane, hydrogenated bisphenol-A and the reaction products of bisphenol-A with ethylene or propylene oxide.
The resin can be formed by the addition of recycled polyethylene terephthalate (PET), such as from soda bottles to the base resin prior to polymerization. PET bottles can be ground and depolymerized in the presence of a glycol, which produces an oligomer. The oligomer can then be added to a polymerization mixture containing polyester monomer and polymerized with such monomer to an unsaturated polyester.
Unsaturated polyester resins can also be derived from the esterification of saturated polycarboxylic acid or anhydride with an unsaturated polyhydric alcohol. Exemplary saturated polycarboxylic acids include oxalic acid, malonic acid, succinic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, hydroxylsuccinic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, 2,2-dimethylglutaric acid, 3,3-dimethylglutaric acid, 3,3-diethylglutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, tetrabromophthalic acid, tetrahydrophthalic acid, 1,2-hexahydrophthalic acid, 1,3-hexahydrophthalic acid, 1,4-hexahydrophthalic acid, 1,1-cyclobutanedicarboxylic acid and trans-1,4-cyclohexanedicarboxylic acid.
Unsaturated polyhydric alcohols which are suitable for reacting with the saturated polycarboxylic acids include ethylenic unsaturation-containing analogs of the above saturated alcohols (e.g., 2-butene-1,4-diol).
Suitable vinyl ester resins include practically any reaction product of an unsaturated polycarboxylic acid or anhydride with an epoxy resin. Exemplary acids and anhydrides include (meth)acrylic acid or anhydride, α-phenylacrylic acid, α-chloroacrylic acid, crotonic acid, mono-methyl and mono-ethyl esters of maleic acid or fumaric acid, vinyl acetic acid, cinnamic acid, and the like. Epoxy resins which are useful in the preparation of the polyvinyl ester are well known and commercially available. Exemplary epoxies include virtually any reaction product of a polyfunctional halohydrin, such as epichlorohydrin, with a phenol or polyhydric phenol. Suitable phenols or polyhydric phenols include for example, resorcinol, tetraphenol ethane, and various bisphenols such as bisphenol-A, 4,4′-dihydroxydiphenyl-sulfone, 4,4′-dihydroxy biphenyl, 4,4′-dihydroxydi-phenylmethane, 2,2′-dihydroxydiphenyloxide, and the like.
Typically, the unsaturated polyester or vinyl ester resin material also includes a vinyl monomer in which the thermosetting resin is solubilized. Suitable vinyl monomers include styrene, vinyl toluene, methyl methacrylate, p-methyl styrene, divinyl benzene, diallyl phthalate and the like. Styrene is the preferred vinyl monomer for solubilizing unsaturated polyester or vinyl ester resins.
Suitable phenolic resins include practically any reaction product of a aromatic alcohol with an aldehyde. Exemplary aromatic alcohols include phenol, orthocresol, metacresol, paracresol, Bisphenol A, p-phenylphenol, p-tert-butylphenol, p-tert-amylphenol, p-tert-octylphenol and p-nonylphenol. Exemplary aldehydes include formaldehyde, acetaldehyde, propionaldehyde, phenylacetaldehyde, and benzaldehyde. Particularly preferred are the phenolic resins prepared by the reaction of phenol with formaldehyde.
The resin may comprise an epoxy resin, i.e., one that contains at least one oxirane group in the molecule. Hydroxyl substituent groups can also be present and frequently are, as well as ether groups. Halogen substituents may also be present. Generally, the epoxy resins can be broadly categorized as being aliphatic, aromatic, cyclic, acyclic, alicylic or heterocyclic. Preferably aromatic epoxide resins are used. One particularly preferred group of aromatic epoxy resins are the polyglycidyl ethers of polyhydric aromatic alcohols, such as, for example, dihydric phenols. Suitable examples of dihydric phenols include resorcinol, catechol, hydroquinone, bis(4-hydroxyphenyl)-1,1-isobutane; 4,4-dihydroxybenzophenone; bis(4-hydroxyphenyl)-1,1-ethane; bis(2-hydroxynaphenyl)methane; 1,5-hydroxynaphthalene and 4,4′-isopropylidenediphenol, i.e., bisphenol A. Of the many epoxy compounds that may be utilized to synthesize the epoxy resins, the one principally utilized is epichlorohydrin, although epibromohydrin is also useful. The polyglycidyl ethers are obtained by reacting epichlorohydrin and bisphenol A in the presence of an alkali such as sodium or potassium hydroxide. The series of epoxy resins sold by Shell Chemical Company under the trademark EPON are useful. Another group of useful epoxy resins are the polyglycidyl ethers derived from such polyhydric alcohols as ethylene glycol; diethylene glycol; triethylene glycol; 1,2-propylene glycol; 1,4-butylene glycol; 1,5-pentanediol; 1,2,6-hexanetriol; glycerol and trimethylolpropane. Also useful are the epoxide resins that are polyglycidyl ethers of polycarboxylic acids. These materials are produced by the reaction of an epoxy compound such as epichlorohydrin with an aliphatic or aromatic polycarboxylic acid such as oxalic acid; succinic acid; glutaric acid; terephthalic acid; 2,6-napthalene dicarboxylic acid and dimerized linoleic acid. Still another group of epoxide resins are derived from the epoxidation of an olefinically unsaturated alicyclic material. Among these are the epoxy alicyclic ethers and esters well known in the art.
Epoxy resins also include those containing oxyalkylene groups. Such groups can be pendant from the backbone of the epoxide resin or they can be included as part of the backbone. The proportion of oxyalkylene groups in the epoxy resin depends upon a number of factors, such as the size of the oxyalkylene group and the nature of the epoxy resin.
One additional class of epoxy resins encompasses the epoxy novolac resins. These resins are prepared by reacting an epihalohydrin with the condensation product of an aldehyde with a monohydric or polyhydric phenol. One example is the reaction product of epichlorohydrin with a phenolformaldehyde condensate. A mixture of epoxy resins can also be used herein.
The epoxy resins require the addition of a curing agent in order to convert them to thermoset materials. In general, the curing agents which can be utilized herein can be selected from a variety of conventionally known materials, for example, amine type, including aliphatic and aromatic amines, and poly(amine-amides). Examples of these include diethylene triamine; 3,3-amino bis propylamine; triethylene tetraamine; tetraethylene pentamine; m-xylylenediamine; and the reaction product of an amine and an aliphatic fatty acid such as the series of materials sold by Henkel Corporation under the registered trademark VERSAMID® curing agents. Preferably the poly(amine-amide) materials such as VERSAMID® curing agents or their equivalents are utilized.
Also suitable as curing agents for epoxies are polycarboxylic acids and polycarboxylic acid anhydrides. Examples of polycarboxylic acids include di-, tri-, and higher carboxylic acids such as, for example, oxalic acid, phthalic acid, terephthalic acid, succinic acid, alkyl and alkenyl-substituted succinic acids, tartaric acid, and polymerized fatty acids. Examples of suitable polycarboxylic acid anhydrides include, among others, pyromellitic anhydride, trimellitic anhydride, phthalic anhydride, succinic anhydride, and maleic anhydride. In addition, aldehyde condensation products such as urea-, melamine-, or phenol-formaldehyde are useful curing agents. Other suitable curing agents include boron trihalide and complexes of boron trihalide with amines, ethers, phenols and the like; polymercaptans; polyphenols; metal salts such as aluminum chloride, zinc chloride and magnesium perchlorate; inorganic acids and partial esters such as phosphoric acid and n-butyl orthophosphite. It should be understood that blocked or latent curing agents can also be utilized if desired; for example, ketimines that are prepared from a polyamine and a ketone.
The amount of the epoxy resin and curing agent utilized can vary, but generally the equivalent ratio of epoxy to amine is within the range of from 0.05:1 to 10:1. Preferably, the epoxy to amine equivalent ratio is within the range of from 0.1:1 to 1:1, and more preferably within the range of 0.3:1 to 0.9:1.
The SAP particles are incorporated into the curable thermoset resin in an amount sufficient to impart flame retardant properties to the cured resin. In general, the SAP particles may comprise up to about 50 wt. % of the resin, and typically between about 1 to about 15 wt. %, most preferably about 10 wt. %. By the term “flame retardant property” is meant that a shaped article comprised of a cured thermoset resin containing the SAP particles will either not be ignitable with a flame or if ignitable by a flame, will self-extinguish the flame within at least about 60 seconds.
The present invention will be further understood from the following non-limiting Examples.
EXAMPLES
Example 1
One unknown in incorporating hydrated SAPs into a composite resin is the effect of the water on resin curing. Water is detrimental to curing and subsequent resin properties. In order to explore this effect, deionized water (5 weight percent of resin) was mixed with a general purpose unsaturated polyester resin. A hardener (methyl ethyl ketone peroxide initiator) for the resin was then added. The resin did not cure to a hard clear cast but eventually turned into an opaque paste. In another test, SAP (10 weight percent of resin) and water (8.5 weight percent of resin) were mixed with an unsaturated polyester resin and hardener. The resin gelled in 32 minutes and thereafter cured to a hard clear cast. Thus, it was observed that hydrated SAP particles can be incorporated into a cured thermoset resin matrix without disrupting the curing process.
Example 2
The fire resistance of the cured resin containing the hydrated SAP (Sample B) was compared to a similarly cured resin without the SAP (Sample A). Both samples were suspended side-by-side on respective copper wires and ignited from the bottom with a propane torch. The flame on Sample A containing no SAP burned up the bar and completely consumed the sample evidencing no fire resistance properties. Sample B, containing the hydrated SAP in accordance with the present invention, self-extinguished the flame in less than five seconds sustaining little damage.
Example 3
Polyacrylamide microspheres (11 grams) were combined with 85% phosphoric acid (17.85 grams) and then dried for four hours at 110° C. and 20 hours at 130° C. in a vacuum oven. The polyacrylamide/phosphoric acid microspheres where ground and sifted through a 300 micron screen. The microspheres (13 grams) were then blended with an epoxy resin composed of 28.69 grams of D.E.R.™ 331 epoxy resin (Dow Chemical) and 10.32 grams of EPIKURE™ 9551 curing agent (Resolution Performance Products LLC) using a high speed mixer and poured into 7 cm diameter aluminum pan. The resin was put into a vacuum oven and degassed. The resin was then cured at 120° C. for two hours. The cured resin disk was suspended on a wire and the bottom side of the resin disk was exposed to a propane torch flame for 60 seconds. The torch flame was removed and the disk had not ignited. The disk was exposed to the torch flame for an additional 150 seconds. The torch flame was removed and the fire extinguished within 6 seconds. The sample retained 91% of its weight. In contrast, an epoxy control without the microspheres completely burned after being ignited by a 30 second torch flame exposure.
Example 4
Polyacrylamide microspheres (7 grams) were combined with diammonium phosphate (13.0 grams) dissolved in water (15.9 grams) and then dried for 20 hours at 120° C. in a vacuum oven. The polyacrylamide/diammonium phosphate microspheres were ground and sifted through a 300 micron screen. The ground microspheres (18 grams) were then blended with 38.5 grams of D.E.R.™ 331 epoxy resin (Dow Chemical) and 14.2 grams of EPIKURE™ 9551 curing agent (Resolution Performance Products LLC) using a high speed mixer and poured into 7 cm diameter aluminum pan. The resin was put into a vacuum oven and degassed. The resin was then cured at 120° C. for two hours. The cured resin disk was suspended on a wire and the bottom side of the resin disk was exposed to a propane torch flame for 60 seconds. The torch flame was removed and the disk had not ignited. The disk was exposed to the torch flame for an additional 120 seconds. The torch flame was removed and the fire extinguished within 5 seconds. In contrast, an epoxy control without the microspheres completely burned after being ignited by a 30 second torch flame exposure.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope thereof. | Flame-retardant synthetic resin articles and methods of making the same are provided whereby flame-retardant SAP particles are incorporated into synthetic resins, especially curable thermosettable resins. The SAP particles are most preferably hydrated with an aqueous flame-retardant solution. In this regard, the flame-retardant solution may consist essentially of water alone or a water solution containing one or more water soluble inorganic flame retardants. When SAP particles are hydrated with an aqueous inorganic flame retardant solution, the SAP particles may thereafter be dried to remove substantially the water component. In such a manner, the inorganic flame retardant will remain as a dried residue physically entrained within the SAP particles. As such, the SAP particles serve as a physical matrix in which the inorganic flame retardant is homogenously dispersed. The SAP particles may then be blended with a synthetic resin as is or alternatively may be ground into more finely divided particles which contain the dried residue of the aqueous inorganic flame retardant solution and then blended with a suitable synthetic resin. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a battery receiving chamber of an electronic device to be worn on a human body and, particularly, to a structure of a battery receiving chamber for water-tightly receiving an air cell battery to which air has to be supplied.
A typical example of a conventional electronic device adapted to be used in a state attached directly to a human body is a hearing aid of the ear-piece type such as shown in FIG. 6. FIG. 6 is a side view of such a hearing aid 1, composed of a casing 2, a microphone 3 provided in an upper portion of the casing 2, electronic circuitry (not shown) including a signal amplifier and provided in the casing 2 for suitably amplifying sound picked-up by the microphone to provide a sound output, a curved sound conduit 4 in the form of a hook to be hanged fittingly on an upper portion of an ear of a wearer for conducting the sound output of the electronic circuitry through its top opening to the ear, and a battery (not shown) for energizing the amplifier. The battery is received in a battery receiving chamber provided in a lower portion of the casing 2, which is closed by a cover 5 as shown.
As shown in FIG. 6, a side face 2A of the casing 2 is shaped to fit the rear side of the ear of the wearer. With the curved sound conduit 4 and the side face 2A of the casing 2, the hearing aid 1 can be worn without giving any abnormal feeling to the wearer.
In order to make it possible to take a bath or to swim while protecting the hearing aid, in particular, the casing 2 thereof, against water, the hearing aid is usually made water-tight, otherwise, internal electric and electronic elements may be damaged.
Such water-tight structure is usually provided by utilizing O-rings of elastic material each in a junction of adjacent constitutional parts.
Such a conventional hearing aid is very effective insofar as the battery to be used is a shielded battery such as a mercury battery, etc.
On the other hand, an air cell, for example, an air-zinc battery, which utilizes oxygen in air to depolarize a positive electrode of the battery chemically by means of reduction of oxygen, is known as having less public pollution problems and a large electric capacity, compared with a conventional mercury battery. Therefore, it is highly desired to use such an air cell for a hearing aid. When such an air cell is to be used as the power source of the hearing aid, it is necessary to supply air to the battery. However, the water proof structure of the conventional hearing aid does not allow the use of an air cell since air can not be supplied to the battery provided within the casing thereof.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a structure of a battery receiving chamber of a water-proof hearing aid, which is capable of introducing a sufficient amount of air thereinto.
According to the present invention, the above object can be achieved by providing through-holes in a wall of a hearing aid which defines a battery chamber and providing a water-proof filter in each of the through-holes, to allow air to flow through the filters while preventing water entry, together with air, into the through-holes from further moving into the battery chamber by the filters.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become more apparent by reference to the following detailed description of the present invention taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a disassembled, perspective view of an embodiment of a battery receiving chamber according to the present invention;
FIG. 2 is a perspective view showing an assembly of the battery receiving chamber shown in FIG. 1;
FIG. 3 is an enlarged, perspective view of a portion of the embodiment shown in FIG. 2;
FIG. 4 is a perspective view showing another embodiment of the present invention;
FIG. 5 is a cross section taken along a line V--V in FIG. 4; and
FIG. 6 is a front view of a conventional ear-piece type hearing aid.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention, applied to a ear-piece type hearing aid, will be described in detail with reference to the drawings.
In FIG. 1 in which components corresponding to those shown in FIG. 6 are depicted by same reference numerals, respectively, a battery receiving chamber 11 in the form of a cylindrical space is formed in a lower end portion of a casing 2 of a hearing aid 1. The battery receiving chamber 11 is associated with a cover member 13. A battery 12 which is flat circular disc in shape and which comprises an air-zinc battery is inserted into the chamber 11 and, then, by fitting the cover member 13 in the casing 2, the battery 12 can be held within the chamber 11. A portion of the casing 2 in which the cylindrical battery receiving chamber 11 is formed is stepped down and an upright protrusion or post 18 is formed in a peripheral portion of the cylindrical chamber 11.
The cover member 13 is adapted to be put on an upper open end of the cylindrical battery receiving chamber 11 as shown in FIG. 2 to close the open end.
Referring to FIGS. 1 and 2 as well as FIG. 3 which shows the cover member 13 in partial cross section, the cover member 13 includes integrally a flange portion 16 having a peripheral notch 19 and shaped to fit with the stepped down portion of the casing 2, and an outer side wall portion 15A extending downwardly from a lower surface of the flange portion 16 to define a recess 15 having substantially the same configuration as an outer configuration of the battery 12. An outer diameter of the side wall portion 15A is slightly smaller than an inner diameter of the cylindrical chamber 11 so that the side wall portion 15A, when inserted into the cylindrical chamber 11 in which the battery 12 is received with the notch 19 being fitted on the protrusion 18 of the casing 2, is fixedly fitted between an outer wall of the battery 12 and the inner wall of the cylindrical chamber 11.
As shown in FIG. 3, an O-ring 10 of elastic material is arranged between the outer surface of the side wall portion 15A and the inner wall of the cylindrical chamber 11 to provide a water-proof structure.
In a central portion of an upper surface of the flange portion 16 of the cover member 13, a circular recess 21 having a shoulder portion 21A is formed in which a circular flap 22 is supported pivotably on a shaft 23 traversing the recess 21. A diameter of the flap 22 is smaller than an inner diameter of the recess 21 such that the flap 22 can close the recess 21 with a gap therebetween which is small enough to prevent water to pass while allowing air or vapor to pass through.
A bottom surface of the recess 21 is formed with a groove having a sharp-angled U shape cross section and a passage or slot is formed in a wall portion of the recess 21, which extends laterally from an end portion of the groove and opens at an outer side wall of the cover member 13. A slide member 35 is provided in the cover member 13. The slide member 35 includes a laterally extending portion 35A and an engaging portion integral with the lateral portion 35A. The lateral portion 35A is inserted into the passage and the engaging portion is slidably received in the groove, so that the slide member 35 is slidable along the groove and, at one extreme position thereof, the lateral portion protrudes from the side wall of the cover member 13 and, at the other extreme position, it is completely retracted in the cover member.
One side portion 22A of the flap 22 is cut away to provide a space for facilitating a lifting operation thereof and the other side portion thereof is pivotably supported by the shaft 23 so that the flap 22 can be pivotally lifted up by the one side thereof. The other side portion 22B of the flap 22 engages with the engaging portion of the slide member 35 so that the lateral portion 35A of the slide member 35 moves in a direction A (FIG. 3) to protrude from the side wall of the cover member 13 into a locking space or undercut 36 formed on the side wall portion of the battery receiving chamber 11 to thereby lock the cover member 13 to the casing 2, when the flap 22 is in a closed position. When the flap 22 is lifted up, the slide member 35 is moved in a direction B (FIG. 3) to retract the lateral portion thereof, in which state a user can detach the cover member 13 from the casing 2.
The bottom surface of the recess 21 is formed with a generally rectangular through-hole 31 surrounded by a rectangular fixing portion 33 in which a rectangular water-proof filter 32 is removably fitted. The filter 32 is composed of a rectangular frame member 32A and a filter member 32B in the form of film formed from porous continuous fibres of water repelling material such as tetrafluoroethylene resin and extended over the frame member 32A.
In operation, after the battery 12 is put in the cylindrical chamber 11, the cover member 13 with the flap 22 lifted up is fitted in the chamber 11 as shown in FIG. 2. In this state, the battery 12 is fixed by the side wall portion 15A of the cover member 13. Then, the flap 22 is pushed down into the recess 21, in which state the lateral portion 35A of the slide member 35 is locked in the locking space 36 of the casing 2 and thus the cover member 13 is locked thereto.
Due to the presence of the O-ring 10 between the cover member 13 and the casing 2, water invasion into the cylindrical battery receiving chamber 11 can be prevented. Since, as mentioned previously, a small gap is provided between the flap 22 and the recess 21, gas such as a mixture of air and water vapor can enter into the recess 21 therethrough.
Water content of the mixture gas, whose particle size is much larger than molecules of air, is blocked by the filter member 32B of the filter 32, allowing only air to pass through into an air hole 37 of the air cell battery 12.
Thus, it is possible to depolarize a positive electrode of the battery chemically by the reduction of oxygen contained in air to thereby generate power with which electric and/or electronic circuit components of the hearing aid are energized. The battery can be exchanged by removing the cover member 13 by lifting up the flap 22, and the filter member 32 also can be exchanged by pulling it out in this state.
FIG. 4 shows another embodiment of the present invention and FIG. 5 is a cross section taken along a line V--V in FIG. 4. In FIGS. 4 and 5, the filter 32 is fitted not in the recess 21 of the cover member 13 but in a through-hole 41 formed in the side wall of the casing 2 and communicated with the chamber 11. The fitting of the filter 32 composed of the frame member 32A and the filter member 32B in the through-hole 41 is performed through a water-proof member 42 of such as elastic material.
A protective member 43 in the form of metal mesh is provided over the through-hole 41 to prevent the filter member 32B from being damaged externally.
With the structure shown in FIGS. 4 and 5, water content of gas entering into the through-hole 41 through the protective member 43 is blocked by the filter member 32B while air is allowed to enter into the battery chamber 11.
Although the present invention has been described as being applied to an ear piece type hearing aid, this description is not meant to be construed in a limiting sense. For example, the present invention is also applicable to other electronic devices which may be attached to wearers.
Various modifications of the disclosed embodiment, as well as other embodiments of the present invention, will become apparent to persons skilled in the art upon reference to the description of the present invention. It is, therefore, contemplated that the appended claims will cover any modifications or embodiments as fall within the true scope of the present invention. | A receiving chamber for an air cell battery for use in an electronic device having a casing 2 in which a battery receiving chamber 11 having an open upper end is defined by a wall portion thereof comprises a cover member 13 for selectively closing the open end of the battery receiving chamber, a through-hole 31; 41 formed in the battery receiving chamber for communicating the battery receiving chamber externally, and filter means 32 provided in the through-hole for repelling the water content of air supplied through the through-hole to the battery receiving chamber while allowing air to pass through. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a monodirectional impeller for centrifugal electric pumps having a permanent-magnet synchronous motor.
[0002] It is known that permanent-magnet synchronous electric motors have a general structure which comprises a stator, provided with an electromagnet constituted by a lamination pack and by corresponding windings, and a rotor, which is arranged between two pole shoes formed by the stator and is crossed axially by a shaft which is rotatably connected to a supporting structure.
[0003] These motors are bidirectional, i.e., at startup the rotor can be induced equally to turn clockwise or counterclockwise.
[0004] This characteristic depends on a plurality of factors, including the arrangement of the polarities of the rotor with respect to the magnetic field generated between the pole shoes of the stator pack when the induction windings are supplied with AC current.
[0005] For this reason, permanent-magnet synchronous motors are currently widely used where the direction of rotation is not important; accordingly, for example they are coupled, in centrifugal pumps, to radial-vane impellers which ensure the same performance in both directions of rotation.
[0006] In order to increase the efficiency of synchronous-motor electric pumps without resorting to the use of particular electronic starting devices, it is convenient to use vanes which are orientated with a certain curvature profile, which clearly presumes a single direction of rotation of the motor.
[0007] Accordingly, electronic starter devices have been devised which guide the motor so that it starts in a single direction of rotation; as an alternative thereto, mechanical devices have been devised which block the rotor when it tends to start in the wrong direction of rotation (reference should be made for example to patent application PD98A000003 of Jan. 8, 1998 in the name of this same Applicant).
[0008] In this manner, monodirectional behavior is ensured in any operating condition assumed by the electric pump.
[0009] However, the system may generate noise during starting and is a limitation as regards reliability (for high-power pumps), since there is a mechanical device which is subjected to repeated stresses, especially during starting.
[0010] A particularly important alternative for a monodirectional synchronous electric pump without mechanical devices for stopping the rotor and without electronic devices (which are reliable but expensive) is constituted by what is disclosed in patent application PD
[0011] [0011] 98 A000058 of Mar. 19, 1998 in the name of this same Applicant.
[0012] This patent application discloses a device which is able to start, with limited power levels, loads which have high moments of inertia, such as impellers with orientated vanes of a centrifugal pump.
[0013] In particular, this is a driving device with a larger angle of free rotation between the rotor and the impeller, so as to obtain, with respect to conventional mechanical couplings, several advantages:
[0014] reduction of the starting torque for starting the motor;
[0015] a consequent reduction of the level of vibrations generated during synchronous operation;
[0016] the motor is rendered monodirectional by means of the correct design of the vanes of the impeller, so that the power absorbed by the load in one direction of rotation is greater than the available power of the motor and is smaller in the opposite direction of rotation.
[0017] Therefore, by designing the motor and the vanes of the impeller so that the power absorbed by the load in one direction of rotation is greater than the available power of the motor and smaller in the opposite direction of rotation, in the first case the impeller goes out of step with respect to the motor, is halted and automatically reverses its motion, whereas in the second case it is driven normally.
[0018] It is thus possible to render the pump monodirectional by utilizing the difference in power between what the motor is able to deliver and the power absorbed by the load in the two directions of rotation (the rotor stops because the power required by the impeller in the wrong direction of rotation is greater than the power that the motor can deliver).
[0019] Although this system provides a fundamental advantage with respect to the prior art, it still has limitations, because monodirectionality is ensured only within a flow-rate/head range; accordingly, it is used in applications where the hydraulic working point does not vary beyond certain limits or, in other words, where the characteristic curve of the duct does not undergo significant variations (this is the case, for example, of washing pumps for dishwashers).
[0020] In the accompanying drawings FIG. 1 plots, for both directions of rotation of the motor, the power absorbed by the motor as a function of the required flow-rate.
[0021] The line A plots the correct direction of rotation, the line B plots the wrong direction of rotation, and the straight line C represents the maximum power that can be delivered by the motor.
[0022] The chart shows three flow-rates Q1, Q2 and Q3, which correspond to three working points, and it is clear that only Q1 and Q2 are the flow-rates for which a single direction of rotation is ensured, since the maximum power that the motor is able to deliver (straight line C) is greater than the power required by the impeller when it turns in the correct direction of rotation (line A) and is smaller than the power required by the impeller when it turns in the opposite direction (line B).
[0023] For the flow-rate Q3, instead, there is a condition in which both power levels, in both directions of rotation, are lower than the maximum deliverable power and therefore monodirectional behavior is not possible.
SUMMARY OF THE INVENTION
[0024] The aim of the present invention is therefore to eliminate the above-noted drawbacks of the above-cited device related to patent application
[0025] Within this aim, a consequent primary object is to provide a pump which is monodirectional over the entire available flow-rate range.
[0026] Another object is to provide all of the above in a constructively simple manner.
[0027] Another object is to have no effect on noise levels.
[0028] Another object is to provide an impeller, if necessary, with deformable vanes enclosed between a double fluid conveyance wall (closed impeller).
[0029] This aim and these and other objects which will become better apparent hereinafter are achieved by an impeller for centrifugal electric pumps having a permanent-magnet synchronous motor, characterized in that its vanes are deformable at least along part of their extension and can change their curvature, when loaded, in one direction of rotation, so that the power required for rotation in that direction is greater than the maximum power that can be delivered by the motor.
[0030] Conveniently, in one embodiment, this aim and these objects are achieved by an impeller for centrifugal electric pumps having a permanent-magnet synchronous motor, characterized in that it comprises:
[0031] a first disk-like element provided with curved nondeformable vanes which are monolithic therewith,
[0032] an annular element, whose dimensions are contained within the inlet dimensions of said nondeformable vanes and which is provided with means for coupling to said first disk-like element, said annular element being provided with flexibly deformable vanes which cantilever outward, are interposed between the nondeformable ones, and are adapted to modify, when loaded, their curvature in one of the directions of rotation so that the power required for rotation in that direction is greater than the maximum power that can be delivered by the motor,
[0033] a second disk-like element, which encloses, together with said first disk-like element, the set of vanes and is rigidly coupled to said nondeformable vanes, leaving the deformable ones free.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Further characteristics and advantages of the invention will become better apparent from the detailed description of embodiments thereof, illustrated only by way of non-limitative example in the accompanying drawings, wherein:
[0035] [0035]FIG. 1 is a chart which plots, for conventional centrifugal pumps, the flow-rate as a function of the power required in the two directions of rotation;
[0036] [0036]FIG. 2 is a sectional view of an impeller according to the invention in a first embodiment, arranged inside a volute of a centrifugal pump;
[0037] [0037]FIG. 3 is an exploded view of the components of FIG. 2;
[0038] [0038]FIG. 4 is a plan view of an impeller according to the invention in a second embodiment;
[0039] [0039]FIG. 5 is a side view of the impeller of FIG. 4;
[0040] [0040]FIG. 6 is a sectional view of an impeller according to the invention in a third embodiment, arranged inside a volute of a centrifugal pump;
[0041] [0041]FIG. 7 is a chart which plots, for centrifugal pumps with impellers according to the invention, the flow-rate as a function of the power required in the two directions of rotation;
[0042] [0042]FIG. 8 is a side view of another impeller according to the invention;
[0043] [0043]FIG. 9 is a front view of the impeller of FIG. 8;
[0044] [0044]FIG. 10 is an exploded perspective view of the impeller of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] With reference to FIGS. 2 and 3, in a first embodiment the impeller according to the invention comprises a disk 10 with a central hollow cup-shaped body 11 which is a component of a driving device 12 described in greater detail hereinafter.
[0046] A plurality of vanes 13 protrudes from a ring 16 which is located on the outside of the cup-shaped body 11 in a corresponding seat 10 a of the disk 10 .
[0047] The vanes 13 are monolithic with respect to the ring 16 , which affects only their part that lies closest to the center.
[0048] The peripheral part can therefore perform flexing movements arising from the elastic characteristics of the material of which they are made.
[0049] The vanes 13 can also be rigidly coupled to the ring 16 (axial and torsional retention) in various manners: by interlocking and/or interference, ultrasonic welding, adhesive bonding.
[0050] The peripheral regions 14 of the vanes 13 are therefore flexibly deformable, as mentioned, and said deformation is greater for the wrong direction of rotation and is optionally limited by the stroke limiting teeth 15 which protrude from the disk 10 alternately with the vanes 13 .
[0051] In order to center the vanes 13 with respect to the teeth 15 , the ring 16 has axial teeth 17 to be inserted in appropriately provided holes 18 of the disk 10 .
[0052] As regards the driving device 12 , it comprises said hollow body 11 and a cover 19 which can also be rigidly coupled to the ring 16 with the vanes 13 .
[0053] The hollow body 11 is provided with an axial hole 20 for the shaft 21 of the rotor, not shown in the figures, of the motor.
[0054] An O-ring gasket 23 acts on the shaft 21 and is accommodated in a corresponding seat of the hollow body 11 .
[0055] The hermetic seal of the device 12 is ensured not only by the gasket 23 but also by the closure of the lid 19 , which is provided by ultrasonic welding, adhesive bonding or other known methods on the hollow body 11 .
[0056] It is possible to provide alternative embodiments which are not hermetic or in which the lid 19 is monolithic with the ring 16 .
[0057] In said ring, a tooth 24 protrudes from the inner wall and is therefore rigidly coupled to the impeller assembly; said tooth 24 interacts with a tooth 25 which protrudes from a ring 26 which can rotate about a shank 27 which is mounted with interference on the shaft 21 and is rigidly coupled thereto.
[0058] A tooth 28 protrudes radially from the shank 27 and interacts, in its rotation, with the tooth 25 of the ring 26 , whose axial extension is such as to affect the path of the rotation of both teeth 24 and 25 .
[0059] Said teeth are arranged axially so that they do not interfere with each other.
[0060] Accordingly, the rotation of the shaft 21 starts the rotation of the tooth 28 , makes said tooth interact with the tooth 25 , turning it until it interferes with the tooth 24 , and finally makes the rotor turn the impeller.
[0061] Grease, with a shock-absorbing function, can be conveniently placed inside the hollow body 11 .
[0062] [0062]FIGS. 2 and 3 also illustrate the volute 29 in which the impeller is arranged.
[0063] With reference now to FIGS. 4 and 5, an impeller according to the invention, in a second embodiment which is simplified with respect to the preceding one, comprises a disk 110 , from which a coaxial shank 111 with a hole 112 for the shaft of the rotor (not shown for the sake of simplicity) protrudes centrally on one side, and from which a plurality of vanes 113 with a curved profile protrudes on the other side.
[0064] The impeller as a whole is formed monolithically.
[0065] According to the invention, the vanes 113 are flexibly deformable along at least part of their extension, so as to modify their curvature, when loaded, in one of the two directions of rotation so that the power required for rotation in that direction is greater than the maximum power that can be delivered by the motor.
[0066] The deformability of the vanes arises from the flexibility of their peripheral regions 114 , which are provided separately from the disk 110 by the molding step by way of an appropriate shaping of the mold.
[0067] By providing the impeller as a single part made of plastics, with the peripheral regions 114 divided from the rest, said regions flex, when loaded, in the wrong direction of rotation and modify their curvature so that in practice they block the rotation.
[0068] Conveniently, teeth 115 protrude from the disk 110 in the peripheral region, are alternated with the vanes 113 , and advantageously act as stop elements which avoid excessive curvatures of said vanes 113 in the wrong direction of rotation, thus avoiding excessive stresses thereto.
[0069] The flexibility of the material would of course allow flexing in the correct direction of rotation as well, but the curvature of the vanes 113 , which matches the fluid threads that form during the rotation of the impeller, causes deformation in the correct direction of rotation to be very limited in practice.
[0070] With reference to FIG. 6, in a third embodiment the impeller according to the invention comprises a disk 210 with a cup-shaped central hollow body 211 which is a component of a driving device 212 similar to the one of the first embodiment.
[0071] A plurality of vanes 213 protrudes from a ring 216 which is arranged on the outside of the cup-shaped body 211 in a corresponding seat 210 a of the disk 210 .
[0072] The vanes 213 are monolithic with respect to the ring 216 , which affects only the part of said vanes that lies closest to the center.
[0073] The peripheral part can therefore perform flexing movements arising from the characteristics of the material of which the vanes are made.
[0074] The vanes 213 can also be rigidly coupled to the ring 216 (axial and torsional retention) in various manners: by interlocking and/or interference, ultrasonic welding, adhesive bonding.
[0075] The peripheral regions 214 of the vanes 213 are therefore, as mentioned, flexibly deformable, and said deformation is greater for the wrong direction of rotation and is limited by teeth 215 which protrude from the disk 210 alternately with the vanes 213 .
[0076] In order to center the vanes 213 with respect to the teeth 214 , the ring 216 has axial teeth 217 to be inserted in appropriately provided holes 218 of the disk 210 .
[0077] Also in this case, the cover 219 is separate from the ring 216 , but it is also possible to provide alternative embodiments in which the cover 219 is monolithic with the ring 216 .
[0078] In this embodiment, the lid 219 of the hollow body 211 has, at its end, a seat 230 for a first shim ring 231 made of ceramic material, sintered material or similar hard material.
[0079] A second shim ring 232 made of ceramic material, sintered material or similar hard material is accommodated in a seat 233 provided at the end of a cylindrical support 234 which is supported by a bush 235 which is rigidly coupled, by means of radial spokes 236 , to a ring 237 which is inserted with interference in a corresponding seat 238 of the volute 229 .
[0080] As an alternative, the support 234 can be monolithic with the bush 235 .
[0081] The ring 232 acts as an axial thrust bearing in order to adjust, in cooperation with the ring 231 , the position that the impeller assumes in the volute 229 and maximize hydraulic efficiency.
[0082] With reference now to FIG. 7, said figure is a chart which plots the flow-rate as a function of power and wherein:
[0083] the line D is the curve related to an impeller with the flexible vanes according to the invention, with the wrong direction of rotation;
[0084] the line C represents the maximum power that the motor can deliver;
[0085] the line A plots the curve related to an impeller with flexible vanes, in the correct direction of rotation.
[0086] The line D clearly shows that for any flow-rate in the wrong direction of rotation, the flexible vane requires more power than the motor can generate (straight line C).
[0087] Accordingly, the motor cannot start in the wrong direction.
[0088] FIGS. 8 to 10 illustrate another possible configuration of the impeller.
[0089] In this case, the impeller according to the invention, which is entirely made of plastics, is generally designated by the reference numeral 310 and comprises a first disk-like element 311 (which is monolithic with respect to a bush 311 a ) which monolithically supports, in this case, three curved nondeformable vanes 312 which are angularly equidistant and, at the center, a rounded shank (which is separated from their inlet region).
[0090] The impeller 310 further comprises an annular element 314 , whose dimensions are contained within the inlet dimensions of said nondeformable vanes 312 ; said annular element has means 315 (described in greater detail hereinafter) for coupling to said first disk-like element 311 .
[0091] The annular element 314 supports, so that they cantilever outward in this case, three curved flexibly deformable vanes 316 which are angularly equidistant and are to be arranged alternately with the nondeformable vanes 312 .
[0092] The annular element 14 is in fact accommodated in a complementarily shaped seat 317 of the first disk-like element 311 .
[0093] The flexibly deformable vanes 316 end externally with respect to the dimensions of the nondeformable vanes 312 , with respect to which they have slightly smaller axial dimensions.
[0094] The flexibly deformable vanes 316 are adapted to modify, when loaded, their curvature in one direction of rotation so that the power required for rotation in that direction is higher than the maximum power that the motor (not shown for the sake of simplicity) can deliver.
[0095] The impeller 310 further comprises a second disk-like element 318 , which encloses, together with said first disk-like element 311 , the set of vanes 312 and 316 and is rigidly coupled, by ultrasonic welding, adhesive bonding or other known methods, to the nondeformable vanes 312 , leaving free the flexibly deformable vanes 316 , which have slightly smaller axial dimensions.
[0096] The second disk-like element 318 has a central hole and its edge 319 protrudes axially so as to form the inlet region for the fluid to be pumped.
[0097] As regards the coupling means 315 , they comprise a shaped portion 320 which is for example polygonal (dodecagonal in the figures), is provided on the internal surface of the annular element 314 , and mates with a complementarily shaped surface 321 of the seat 317 .
[0098] The coupling means 315 comprise a specific number of tabs 322 which are substantially radial, are angularly equidistant, protrude from the annular element 314 , are inserted between the vanes 316 and end with respective axially elongated hooks 323 , which engage by snap action, after elastic deformation, the first disk-like element 311 by insertion in suitable through holes 324 thereof.
[0099] The seat 317 of course has a shape which also accommodates the tabs 322 .
[0100] The hooks 323 inserted in the through holes 324 prevent any axial movement of the assembly constituted by the disk 314 and the vanes 316 .
[0101] The coupling means 315 determine the exact mutual positioning of the vanes 312 and 316 .
[0102] The peripheral part of the vanes 316 can thus perform flexing movements which arise from the elastic characteristics of the plastic material of which they are made.
[0103] The deformation is greater for the wrong direction of rotation, and the vanes 316 modify their curvature so that in practice they block the rotation.
[0104] The flexibility of the material would of course also allow flexing in the correct direction of rotation, but the curvature of the vanes 316 , which matches the fluid threads that form during the rotation of the impeller 310 , causes the deformation in the correct direction of rotation to be very small in practice.
[0105] In practice it has been observed that the intended aim and objects of the present invention have been achieved.
[0106] With the flexible-vane impeller, monodirectionality is in fact ensured for all flow-rates/heads.
[0107] This is achieved in a constructively simple manner and has no effect on noise levels.
[0108] The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept.
[0109] Thus, for example, the change in the curvature of the vanes can be provided by means of a hinge, even of the film type, which connects each peripheral part to the central one.
[0110] In the embodiment of FIGS. 8, 9 and 10 , even if the flexible vanes yield due to wear, the nondeformable vanes continue to give their constant contribution to the pumping action.
[0111] All the details may further be replaced with other technically equivalent elements.
[0112] In practice, the materials employed, so long as they are compatible with the contingent use, as well as the dimensions, may be any according to requirements.
[0113] The disclosures in Italian patent applications Nos. PD2000A000176 and PD2001A000110, from which this application claims priority, are incorporated herein as reference. | A monodirectional impeller for centrifugal electric pumps having a permanent-magnet synchronous motor, having vanes which are deformable at least along part of their extension so as to change their curvature, when loaded, in one direction of rotation, so that the power required for rotation in that direction is greater than the maximum power that can be delivered by the motor. | 5 |
TECHNICAL FIELD
This invention relates generally to methods for liquid phase epitaxy and particularly to such methods that are selective in the area and materials on which they grow epitaxial layers.
BACKGROUND OF THE INVENTION
Many modern technological applications require high quality crystals for use in, for example, semiconductor and optical devices. Accordingly, many crystal growth techniques have been developed and brought to a high degree of perfection.
One technique of particular interest for growth of semiconductor devices such as, for example, lasers and photodetectors, is liquid phase epitaxy (LPE). In this technique, a boat, typically comprising carbon, holding a semiconductor wafer is placed under a melt containing semiconductor material. Prior to contact with the wafer or substrate, the solution is saturated or slightly undersaturated and has an initial temperature, T. The temperature of the melt is now decreased after contact with the substrate and epitaxial growth begins. After the desired amount of epitaxial growth has occurred, the wafer with the epitaxial layer is removed from contact with the solution by sliding the boat. Further layers may be grown with varying thicknesses, compositions, etc.
Most LPE growth techniques are directed toward obtaining uniform growth, i.e., obtaining growth on all areas contacted by the melt. However, selective area liquid phase epitaxy techniques are known and useful. One prior art selective area growth technique using LPE involved the use of a dielectric film deposited on a GaAs surface of a dielectric insert to serve as a mask. In this technique, no epitaxial layer will grow over the masked surface while an epitaxial layer grows over the unmasked surface. For a more detailed description of this technique, see, for example, U.S. Pat. No. 3,978,426 issued on Aug. 31, 1976 to R. A. Logan et al.
SUMMARY OF THE INVENTION
We have found a new lateral selective area growth technique that uses liquid phase epitaxy. The method comprises contacting a structure comprising a first semiconductor material comprising at least one constituent and a second semiconductor material comprising at least two constituents with a growth solution or melt. The growth solution comprises at least two constituents of the first and second materials. The temperature is raised and there is initially a thermodynamic nonequilibrium state resulting in dissolution of the crystal surface and the formation of a boundary layer in the growth solution and subsequent growth of a thin graded composition as the temperature is lowered. The temperature should be raised at least 0.1 degree C. and the subsequent decrease is less than the increase. The growth follows dissolution as one material from the bulk of the liquid will diffuse rapidly into the boundary layer. In one preferred embodiment, the first material comprises GaAs and the second material comprises Al x Ga 1-x As with x greater than approximately 0.15 and the melt comprises a Ga solution of AlGaAs. The method appears especially useful for growing structures comprising a constituent having a high distribution coefficient in the melt. As the structure is brought into contact with the melt containing the high distribution coefficient constituent, the boundary layer becomes depleted in this element and rich in another constituent relative to the bulk of the melt. Growth ensues as Al from the bulk of the liquid diffuses into the boundary layer. In yet another preferred embodiment, the method is used to grow a lateral double barrier buried heterostructure laser.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic diagram of a lateral double barrier buried heterostructure laser fabricated by the method of this invention; and
FIG. 2 is a plot of the temperature dependence of the threshold current for a laser according to FIG. 1 with the temperature in degrees C. being plotted horizontally and the threshold current being plotted vertically.
DETAILED DESCRIPTION
Our invention will be described by reference to fabrication of double barrier double heterostructure on a GaAs substrate. The structure is schematically illustrated in cross section in FIG. 1. The device comprises a substrate 1, a first epitaxial layer 3, a second epitaxial layer 5, a third epitaxial layer 7, and two barrier layers 9. The structure further comprises burying layers 15, 17, 19, and 21. The first epitaxial layer has a first conductivity type and the third epitaxial layer has a second conductivity type. The second epitaxial layer is the active layer and may be either first or second conductivity type. Burying layers 15, 17, and 21 have a second conductivity type and burying layer 19 has a first conductivity type. In a preferred embodiment, the first conductivity type is n-type and the second conductivity type is p-type. In a further preferred embodiment, the first and third epitaxial layers comprise Al 0 .3 Ga 0 .7 As and the second epitaxial layer comprises GaAs. The barrier layer and the first burying layer comprise Al 0 .65 Ga 0 .35 As and the additional burying layers comprise Al 0 .16 Ga 0 .84 As. The GaAs layer is thus the semiconductor material comprising at least one constituent and the Al 0 .3 Ga 0 .7 As layers are thus the semiconductor material comprising at least two constituents. The mesa, which had a stripe width of approximately 3 μm, was formed by selective chemical etching, using known techniques, into the GaAs substrate. The regrowth steps, i.e., growth of the burying and barrier layers, consisted of the selective growth described in the next paragraph followed by regrowth of Al y Ga 1-y As with a composition factor y selected to form x c -x eff approximately equal to 0.01 to ensure single mode operation of the laser so fabricated. It is to be understood that nominal amounts of both undesired impurities and desired dopants may be present. The latter layers were grown from p-type and n-type melts to provide current confinement. The operation of the double barrier double heterostructure laser, which was invented by W. T. Tsang, is described in Applied Physics Letters, 38, pp. 835-838, 1981.
The double barrier double heterostructure laser reduces beam divergence of the laser without degrading the confinement of carriers in the active layer. Hence, the device characteristics are stabilized and lasing can occur with increasing operating temperature. The presence of the barrier layers ensures minimal lateral carrier leakage out into the burying layers at high temperatures in situations when the composition factor x b of the burying layer is x b less than or equal to approximately 0.2. To form a lowest order mode optical cavity in devices such as the buried heterostructure, the buried optical guide, and the stripe buried heterostructure lasers, it is desirable to have the x b of the burying layer only very slightly higher than the effective value of the effective refractive index of the mesa layers transverse to the junction. The small refractive index difference allows fundamental mode operation in the lateral direction with reasonably wide stripes and narrow beam divergence as well as reduced optical scattering losses due to side wall roughness of the etched mesas.
The selective regrowth was reproducibly achieved by placing the GaAs substrate with the above-described etched multilayer mesas on the surface under the Al 0 .65 Ga 0 .35 As melt at a constant temperature of approximately 750 degrees C. The furnace temperature was then increased approximately 1 degree to improve wetting by a melt back estimated as being no more than 0.2 μm. As the furnace temperature is adjusted, i.e., increased, a very slight overshoot, that is, an increase greater than desired, in the furnace temperature occurs which causes a melt back on the rise in the temperature and regrowth on the subsequent very slight decrease, less than 1 degree C., in the temperature. The increase should be at least 0.1 degree C. Thus, the temperature is first raised and then lowered to obtain the desired selective growth. After approximately 6 minutes, but before the furnace temperature is completely equilibrated, the wafer was placed under the second melt comprising Al 0 .16 Ga 0 .24 As and the furnace cooling was initiated at a rate of approximately 0.4 degrees C./min and the remaining regrowth, i.e., the growth of burying layers 17, 19, and 21, was formed in the usual manner. The sample was then cleaned, metallized, and cleaved to form the standard laser chips. The initial preferential growth of the Al 0 .65 Ga 0 .35 As over the GaAs surfaces in both the active stripe side walls and the etched GaAs substrate was clearly apparent in scanning electron microscope cross sections examined by scanning electron microscope photographs. As the selective growth occurs only briefly, the barrier layers, i.e., layers 9, are very thin but are alongside the entire length of the sidewalls of the active stripe. This lateral selective area growth may be achieved in wafers with thickness as thin as 0.15 μm. Additionally, the barrier layers are generally very uniform in shape and in thickness over the wafer and they are symmetrical with respect to a vertical line through the center of the mesa.
The selective growth, i.e., the barrier layers and layer 15, results because of the initial nonequilibrium state of both the GaAs and the Al x Ga 1-x As surfaces when they are contacted initially with the growth solution. Due to the nonequilibrium state, the thermodynamics of the system results in dissolution of the crystal surface with a resulting formation of a boundary layer in the melt adjacent to the crystal surface followed by growth of a thin graded compositional layer. For GaAs in contact with the Al-containing solution, the boundary layer is depleted in Al and rich in As relative to the bulk of the solution. The increase in temperature enhances this situation. Growth follows the initial dissolution as Al from the bulk of the liquid diffuses rapidly into the boundary layer. If the initial semiconductor surface comprises Al, the amount of dissolution and regrowth will be small since the high Al distribution coefficient for the Al-Ga-As system requires that the boundary layer solution be rapidly saturated. The distribution coefficient, which is the ratio of the composition in the solid to that in the liquid, is desirably high for at least one constituent. The distribution coefficient for Al is approximately 100.
Although described specifically with respect to fabrication of a DBDH laser, our method may be used to fabricate other devices. The cross section of the barrier layers is almost invariably lens-like, i.e., has a nonplanar surface, and consequently, devices grown by our method can be used to form integrated astigmatic, approximately cylindrical lenses at the mirror ends of etched cavity lasers. Furthermore, integrated cylindrical lenses at the end of the etched cavity lasers may have their focal lengths controlled by the growth times. The integrated cylindrical lens will then modify the beam divergence in the vertical direction. If the Al 0 .16 Ga 0 .84 As burying layer is omitted, a reflective film coated over the cylindrical lens would further reduce the threshold of the etched cavity lasers.
FIG. 2 shows the temperature dependence of the pulsed threshold current of a double barrier double heterostructure laser fabricated according to this invention. The inset shows the L-I characteristics. The diodes operated at temperatures as high as 280 degrees C. with the threshold current of 340 mA and represent the highest temperature any buried heterostructure laser is operated at. Clear fundamental mode operation was observed with a half-power full width of approximately 18 degrees. The difference in refractive inclines between the mesa and the burying layers is small and consequently, optical scattering losses due to the side wall roughness of the mesa are reduced. This was evidenced by the absence of structure in the far field pattern observed in loss stabilized buried optical guide lasers.
Although described with respect to the growth of structures having AlGaAs layer grown on GaAs, it is to be understood that our method may be used with other materials systems. | A lateral selective area liquid phase epitaxy method useful for the fabrication of, for example, a double barrier buried heterostructure laser, is described. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit U.S. Provisional Patent Application No. 62/239,687 filed Oct. 9, 2015, which is incorporated herein by reference.
TECHNICAL FIELD
The technology herein relates to a mechanical design for the efficient attachment and detachment of electronic pens and pencils of various sizes and thicknesses to electronic tablets, computers, personal information devices and other display and input devices of various sizes and thicknesses.
BACKGROUND OF THE INVENTION
With Microsoft's™ introduction of the Microsoft Pen™ with their line of Surface Pro™ computers in February 2013 and the September 2015 introduction of the Apple Pencil™ for the iPad Pro™, electronic pens and pencils have gone mainstream. Yet, three years after the introduction of the Microsoft Pen™, the way to attach and detach an electronic pen to an electronic tablet remains either through a fabric loop that attaches to the back of the tablet or to the back of a keyboard cover that attaches to the tablet, or more recently, with the introduction of the Microsoft Surface Pro 4™ and the Microsoft Surface Book™, by attaching the pen magnetically to one side of the tablet. However, attaching an electronic pen to a tablet magnetically makes it very easy for the pen to be knocked out, dropped, and lost. Moreover, Apple™ has not announced any attachment mechanism that would secure its Apple Pencil™ to its associated iPad Pro™ in any manner. In fact, the new Apple Pencil™, while an amazing piece of art and technology, does not even include a clip. Without a clip, an electronic pen or pencil is prone to roll over smooth resting surfaces, fall to the ground, and if not noticed, get forgotten and lost.
In addition, losing an electronic pen or pencil that cost anywhere from $50 to $100 may not only be costly, it may also amount to a major nuisance and a substantial loss of productivity until a replacement had been obtained.
Since most electronic tablets designed for professional use, and even new generations of smart phones, are expected to support an electronic pen or pencil in the future, it is only natural to expect that these tablets also include a simple coupling mechanism that would fasten and unfasten such pens and pencils from their associated tablets and smart phones quickly, securely, and conveniently.
SUMMARY OF THE INVENTION
The invention that I conceived and disclose may be embodied to solve one, some, or all of the problems mentioned above by adding a clip with a pointed triangularly shaped protrusion “nose”, or depression, at the tip of the clip that is either magnetic or affected by magnetism and a matching, but slightly wider, corresponding well or sheath, at the side of the accompanying electronic tablet that includes a corresponding matching nose or depression. The electronic pen can then be attached “latched” and detached “unlatched” from its accompanying tablet by inserting the pen's clip into the matching sheath that is built into the tablet. The pen can be securely fastened, or latched, into the tablet once the magnetized triangularly shaped protrusion or depression rests in the corresponding metallic protrusion or depression on the side of the sheath or well, making the electronic pen unlikely to slide out of its sheath or well even when the tablet is held upside down.
If this approach is implemented by tablet manufacturers, the length and width of the pen clip and its matching sheath may become standard for all tablet manufacturers thereby allowing interchangeability of electronic pens of various lengths, thicknesses, and manufacturers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a three-dimensional perspective front view of a tablet computer with a sheath and an electronic pen attachable to the latch.
FIG. 2 shows a three-dimensional perspective side view of an electronic pen and a matching sheath where the sheath is encased into its own enclosure that may be independent from an electronic tablet or personal information display device.
FIG. 3 shows an alternative three-dimensional perspective view of an electronic pen and a matching encased sheath that reveals an opening for the encased sheath to receive the clip of an electronic pen that uses a triangular protrusion at the tip of the clip for latching the pen to the sheath.
FIG. 4 shows an alternative three-dimensional perspective side view of an electronic pen with an encapsulated matching sheath that uses an inverse magnetic locking mechanism with a depression rather than a protrusion at the tip of the clip for latching the pen to the sheath.
FIG. 5 shows an alternative three-dimensional perspective view of an electronic pen and matching encapsulated sheath that highlights the simplicity of the opening of the encapsulated sheath.
FIG. 6 illustrates how the encapsulated sheath can be fitted in the case of an electronic tablet or a personal information display and input device, or into the protective case of an electronic tablet or a personal information display and input device.
FIG. 7 illustrates a three-dimensional perspective view of an encapsulated sheath that is fully integrated into the case of an electronic tablet or personal information display and input device, or into the protective case of an electronic tablet or personal information display and input device.
FIG. 8 illustrates a three-dimensional perspective view of an electronic pen coupled to an encapsulated sheath seated on the side of an electronic tablet or personal information display and input device, or inside the protective case of an electronic tablet or personal information display and input device.
FIG. 9 illustrates an alternative view of a three-dimensional perspective view of an electronic pen coupled to an encapsulated sheath seated on the side of an electronic tablet or personal information display and input device, or inside the protective case of an electronic tablet or personal information display and input device.
DETAILED DESCRIPTION
FIG. 1 shows an exemplary electronic tablet computer 10 with a sheath 12 and an electronic pen 14 attachable to the sheath. The tablet computer 10 may have a touch sensitive digital display screen 16 configured to sense as an input the tip 18 of the electronic pen. A tablet computer with a touch sensitive digital display screen may be viewed as conventional for purposes of the disclosure of this invention. The tablet computer may also be a cellular smart phone, personal digital assistant, electronic book or other similar portable electronic device (collectively referred to as an electronic display device) in which an electronic pen may be used as an input device.
The housing 20 for the tablet computer 10 may be formed of plastic or metal and provide a protective casing for the electronic components in the housing and for the display screen 16 . The housing includes a side edge 22 that may, for example, have a height of greater than eight inches and a thickness in the range of 3 millimeters to an inch and one half. These dimensions are exemplary and depend on the type, model, and manufacturer of the tablet computer.
The side edge of the housing is configured to include the sheath 12 . The sheath may be an elongated slot, chamber, recess or other structure configured to receive the electronic pen. The sheath may be open at both ends, shorter in length, or longer in length than the clip, integrated into the side edge 22 of the housing 20 for the tablet computer, or encapsulated in an enclosure that may be completely independent of the housing 20 of the exemplary electronic tablet 10 . The clip 24 of the pen may be made of a pliable material, such as plastic or metal, that can easily bend and slide into an opening 26 of the sheath 12 and enters the sheath. A finger 28 of the sheath slides between the clip 24 and the body of the pen 15 . The finger 28 may have a length longer than the length of the clip. A latch 30 on an interior surface of the finger engages an end region 32 of the clip 24 . The latch may be a magnet that holds the end region 32 of the clip 24 . The latch 30 may be a protrusion or a recess that engages with a nose or a depression on the end region 32 of the clip 24 . When secured to the sheath 12 , the pen 14 is held to the side edge 22 of the tablet computer by the engagement between the sheath 12 and the clip 24 .
FIG. 2 illustrates an exemplary embodiment of how the sheath 12 may be encapsulated in an enclosure 36 that may be completely independent of the housing 20 of the exemplary electronic tablet 10 of FIG. 1 .
FIG. 3 shows an alternative three-dimensional perspective view of an electronic pen 14 and a matching encapsulated sheath 12 that reveals an opening 26 for the encased sheath 12 to receive the clip 24 of an electronic pen 14 that uses a triangular protrusion 32 at the tip of the clip for latching the pen 14 to the latch 30 of the sheath 12 .
FIG. 4 shows an alternative three-dimensional perspective side view of an electronic pen 14 with an encapsulated matching sheath 12 that uses an inverse magnetic locking mechanism with a depression 33 rather than a protrusion at the tip of the clip for latching the pen 14 to the latch 31 of sheath 12 .
FIG. 5 shows an alternative three-dimensional perspective view of an electronic pen 14 and matching encapsulated sheath that highlights the simplicity of the opening 26 of the encapsulated sheath.
FIG. 6 illustrates a three-dimensional perspective view of how the independent sheath enclosure 36 can be fitted into the case 20 of an electronic tablet or personal information display device 10 , or into the protective case of an electronic tablet or a personal information display device. The independent sheath enclosure 36 may be attached to the side edge 22 of the tablet computer 10 by mechanical means or by gluing it directly into the side edge 22 of the tablet computer.
FIG. 7 illustrates an alternative three-dimensional perspective view of an encapsulated sheath that is fully integrated into the case 20 of an electronic tablet 10 that reveals the opening 26 of the encased sheath for receiving the clip 24 of electronic pen 14 .
FIG. 8 illustrates yet another three-dimensional perspective view of an electronic pen 14 coupled to an independent sheath enclosure 36 that is seated on the side of an electronic tablet or personal information display device 10 , or inside the protective case of an electronic tablet or personal information display and input device 10 .
FIG. 9 illustrates yet another alternative three-dimensional perspective view of an electronic pen 14 coupled to a sheath seated on the side of an electronic tablet or personal information display and input device 10 , or inside the protective case of an electronic tablet or personal information display and input device, though the opening 26 of a fully integrated or independently encapsulated sheath 12 .
The invention may be embodied as a sheath with a latch; the latch may be magnetic or mechanical, or both. The sheath may be open on both ends, or closed on one end; it may be shorter than the length of the clip, about equal in size, or longer; it may be integrated into the side edge of the housing for the tablet computer (or a protective case of an electronic tablet or personal information display and input device), or encapsulated in an enclosure that may be completely independent of the housing of the exemplary electronic tablet (or a protective case of an electronic tablet or personal information display and input device).
While exemplary embodiments of the invention are disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. | A sheath, or an encapsulated sheath, within tablet computers, smart phones, and similar electronic devices, or with enclosures for such electronic devices that would enable the seamless latching and unlatching of electronic pens of various sizes and thicknesses to such devices, or enclosures to such devices, through the pens' integrated flexible clips. | 5 |
This is a continuation of application Ser. No. 07/837,158, filed Feb. 18, 1992 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to an automotive window glass, and particularly, but not exclusively, to an automotive window glass with a film for screening the inside of a car from solar radiation, and an antenna conductor.
2. Description of Related Art
Recently, there is a tendency that automotive window glasses increase in area, whereby solar radiation energy is given more in the inside of a car. Thus, the inside is air-conditioned to prevent it from a rise in temperature, and in order to reduce a cooling load, a film for screening the inside from the solar radiation has been used so far.
Moreover, in the automotive window glass, particularly in a windshield, it is required, from a security viewpoint, to use a laminated glass that transmits 70 percent or more of visible light, and it is also required, from a designing viewpoint, that if the glass is coated with a heat-ray intercepting film, the appearance of such glass is not so much different in color from that of a glass having no heat-ray intercepting film: the glass should appear nearly achromatic like the glass having no heat-ray intercepting film, and should be prevented from dazzling reflections of light.
It is further required that the radio waves radiating and receiving characteristics of antennas for a portable telephone or a global positioning system (GPS) set in the inside of the car, or the receiving characteristics of antenna conductors secured to the outer surface of the automotive window glass is not damaged due to a heat-ray intercepting film sandwiched in between laminated glasses of the automotive window glass. One example of the latter is disclosed in Japanese Laid Open Patent No. 177601/1990, in which the heat-ray intercepting film is made of chromium oxynitride (CrN x O y ) or titanium oxynitride (TiN x O y ), and it is reported that the antenna sensitivity was not damaged at all.
However, the disclosed automotive window glass is such that a surface of a single sheet glass is covered with a chromium or titanium oxynitride film. It is, therefore, not a laminated glass having a heat-ray intercepting film, and does not appear nearly achromatic, so that it is not usable for the car.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an automotive window glass which does not dazzle in light so as to match its color to that of a car, and screens the inside of the car from solar radiation so as to reduce a load for cooling the inside.
Another object of the invention is to provide an automotive window glass in which if an antenna is secured thereto, the radio waves receiving characteristic of the antenna is not damaged by a heat-ray intercepting film used therewith.
A further object of the invention is to provide an automotive window glass in which if an antenna is provided in the inside of a car, the radio waves radiating and receiving characteristic of the antenna is not damaged by a heat-ray intercepting film used therewith.
In accordance with an aspect of this invention, in an automotive window glass comprising a pair of transparent sheet glasses and a transparent resin film with which the pair of sheet glasses are stuck together, the window glass further comprises a second film sandwiched between one of said pair of sheet glasses and the transparent resin film so as to screen the inside of a car from solar radiation, the second film having any one of the following compositions represented by chemical formulas with which atomic ratios are defined.
(A) ZrN x O y: 0.5≦x≦0.8 and, 0.8≦x+y≦1.2
(B) TiN x O y: 0.2≦y≦0.8 and, 1.4≦x+y≦1.8
(C) CrN x O y: 0.1≦y≦0.8 and, 1.4≦x+y≦1.8
When in Formula A, x is, and in formulas B and C, y are larger than 0.8, the characteristic of the heat-ray intercepting film deteriorates, and the window glass becomes so yellowish as not to be suitable for the car. When in Formula A, x is smaller than 0.5; in Formula B, y is smaller than 0.2; and in Formula C, y is smaller than 0.1, the film characteristic deteriorates, the absorption of visible light becomes high, whereby the window glass becomes not transparent enough, and the sheet resistivity becomes small, whereby it is impossible to obtain such a window glass as to be transparent enough, to have a good heat-ray intercepting characteristic, and to be transmissible of electromagnetic waves.
When in Formula A, x falls within 0.5-0.8, and (x+y) falls within 0.8-1.2; in Formula B, y falls within 0.2-0.8, and (x+y) falls within 1.4-1.8; and in Formula C, y falls within 0.1-0.8, and (x+y) falls within 1.4-1.8, the window glass of this invention, which includes the heat-ray intercepting film, was compared with a window glass which includes no such film but, as for the rest, is the same as that of this invention. Coordinates a and b of the two window glasses on the Hunter chromaticity plane were examined, respectively, and respective differences Δa and Δb between the two window glasses were calculated. As the result, it was possible to fall the differences Δa and Δb within -5-+5, and according to observation with the naked eye, there were scarcely any difference between the two window glasses.
Sheet resistivities of the heat-ray intercepting film are 1 kΩ/□ or more, so that respective antennas secured to the window glass of this invention, and loaded in the car to which such window glass is applied will be able to receive well, and radiate or receive well radio waves.
In a preferred embodiment of this invention, the second film has such a thickness as to transmit seventy percent or more of visible light. The thickness of the zirconium, titanium or chromium oxynitride film should be determined upon consideration of the visible-light transmissivity, heat-ray intercepting characteristic and colorific appearance of the window glass. In order to obtain seventy percent of more of the visible-light transmissivity, it is preferable to determine the thickness within a range of 3-15 nm, particularly, 5-10 nm. When the thickness is less than 3 nm, the heat-ray intercepting characteristic becomes not enough, and when it is more than 15 nm, the visible-light transmissivity deteriorates, whereby the window glass is not transparent enough.
Various kinds of sheet glasses can be used for the transparent sheet glass of this invention. For example, colorless sheet glasses or heat-ray intercepting sheet glasses of a bronze, grey or blue color, manufactured under the float process will be usable, and may also be treated under bending and/or tempering processes. The refractive index thereof is about 1.52.
As a material for the transparent resin film for sticking the pair of transparent sheet glasses to each other, it is preferable to use such a resin that the refractive index thereof is the same as that of the transparent sheet glasses. For example, it is preferable to use polyvinyl butyral whose refractive index is about 1.52, because it is excellent for the adhesive force and weatherproofness.
Moreover, in a preferred embodiment of this invention, an antenna conductor is provided on the outer surface of the other of the pair of sheet glasses, or between the inner surface of the other sheet glass and the transparent resin films. In this connection, the reception ability of the antenna conductor does not deteriorate, and the window glass appears nearly achromatic. The antenna conductor may be made, for example, by means of printing and then baking a silver paste on, or securing fine conductive wires to the surface of the sheet glass.
Various coating methods,such as a sputtering, ion-plating or vacuum arc-deposition method, of forming a film after atomizing a material therefor in a low atmospheric pressure are available for forming the heat-ray intercepting film of this invention. Particularly, the sputtering method is very suitable for a laminated glass that is very excellent in a heat-ray intercepting characteristic. The source of the sputtering method may be either direct or high frequency current.
When the zirconium, titanium or chromium oxynitride film is formed by the sputtering method, the targets used for the respective methods are made of zirconium, titanium or chromium, and the atmosphere during sputtering may include nitrogen and oxygen. The ratio between nitrogen and oxygen included in the formed film depends upon the composition and pressure of the atmosphere during sputtering. To stick the pair of transparent sheet glasses to each other with the transparent resin film, various well-known methods are available.
Respective amounts of nitrogen and oxygen in the heat-ray intercepting film of this invention are determined in relation to metals included in the film, so that the window glass is prevented from dazzling reflections of light, and has a high transmissivity of visible light and a high heat-ray intercepting characteristic. Further, if an antenna conductor is secured to the window glass of this invention, the reception ability of the antenna conductor does not deteriorate, because the window glass of this invention has a high electric resistance.
The invention will now be described by way of some examples with reference to the accompanying drawings, throughout which like parts are referred to like references.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-3 are fragmentary sectional views of automotive window glasses according to first to third embodiments of this invention, respectively; and
FIG. 4 is a perspective view of the automotive window glass of FIG. 2.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring initially to FIG. 1, it will be seen that an automotive window glass 6 comprises a pair of transparent sheet glasses: first sheet glass 2 and second sheet glass 3, a heat-ray intercepting film 1 and a transparent resin film 4. The outer surface of the first transparent sheet glass 2 faces the outdoors, and the inner surface thereof is coated with the heat-ray intercepting film 1. The transparent resin film 4 sandwiched between the heat-ray intercepting film 1 and the second transparent sheet glass 3 sticks the second transparent sheet glass 3 to the first transparent sheet glass 2 that is coated with the heat-ray preventing film 1. The outer surface of the second sheet glass faces the inside of a car.
In FIG. 2, the automotive window glass 6 has an antenna conductor 5 between the transparent resin film 4 and the second transparent sheet glass 3, the antenna conductor 5 being made of a fine copper wire that extends vertically downwards along the axis of the window glass 3 as illustrated in FIG. 4. In FIG. 3, the automotive window glass 6 has antenna conductors 5 secured to the outer surface of the second transparent sheet glass 3.
EXAMPLE 1
Both a heat absorbing glass (manufactured by Nippon Sheet Glass Co., Ltd., and sold under the name of "BRONZEPANE"), which is 2.1 mm in thickness, bronze in color, molded in a windshield size of a car and washed, and a 10 cm square of the glass for examining its composition and so forth are placed in a vacuum chamber of a sputtering device, from which air is exhausted to 0.004 Pa.
Then, a mixed gas having a ratio of 100 cc of argon to 180 cc of nitrogen is supplied to the vacuum chamber until its pressure becomes 0.4 Pa. 30 amperes of an electric current are supplied to the target of metallic zirconium to perform sputtering of predetermined duration, and obtain a film of 7 nm thickness on the concave surface of the heat absorbing glass and one surface of the 10 cm square of the glass. The latter is examined with an ESCA analyser, and it becomes clear that the film is of zirconium oxynitride. A result of its quantitative analysis is shown in Table 1.
TABLE 1__________________________________________________________________________Characteristics of Heat-ray Intercepting Films and ApplicationThereof to Laminated Glasses Laminated Glass Transmissivity Reflectivity on Dif. bet. the outdoors sideHeat-ray Intercepting Film glasses Diff. Diff. Sheet Solar with and on the on the Atomic resis- Thick- Visible radi- without Hunter Visible HunterTest Chemical ratio tivity ness light ation the film plane light planeSeries formula x y (Ω/□) (nm) (%) Tg (%) ΔTg (%) Δa Δb (%) Δa Δb__________________________________________________________________________Ex. 1 ZrN.sub.x O.sub.y 0.6 0.4 3.4k 7 71.5 59.6 13.2 -1.2 1.5 7.9 0.4 -3.1Ex. 2 TiN.sub.x O.sub.y 1.2 0.4 1.5k 7 71.7 59.7 13.1 -1.7 2.5 7.7 0.5 -3.5Ex. 3 CrN.sub.x O.sub.y 1.2 0.4 50k 6 70.5 62.8 10.0 -1.2 1.1 8.9 0.2 -2.3Ex. 4 ZrN.sub.x O.sub.y 0.8 0.2 80k 9 71.0 62.3 10.5 -1.4 3.6 9.5 0.2 -5.1Ex. 5 TiN.sub.x O.sub.y 0.9 0.7 50k 8 70.9 59.2 13.6 -2.1 4.1 8.9 0.2 -3.5Ex. 6 CrN.sub.x O.sub.y 0.8 0.8 500k 7 70.3 63.7 9.1 -1.3 2.9 9.1 0.1 -3.1Comp. ZrN.sub.x O.sub.y 0.9 0.3 500k 11 71.2 65.3 9.5 -1.3 6.1 10.5 0.1 -6Ex. 1Comp. TiN.sub.x O.sub.y 0.8 1.0 100k 10 71.8 60.8 12 -2.3 6.5 10.6 0.3 -5.9Ex. 2Comp. CrN.sub.x O.sub.y 0.5 1.1 >2M 9 70.4 66.3 8.5 -1.2 6.2 8.9 0.2 -4.1Ex. 3__________________________________________________________________________
Oxygen in the film seems to have been supplied from the gas remained in the vacuum chamber before the sputtering is performed, or from the surface of the heat absorbing glass. It is noted that the sheet resistivity of the film is 3.4 k/Ω/□.
A transparent glass molded in the same size as that of the heat absorbing glass and having a thickness of 2.1 mm is stuck, with polyvinyl butyral, to the surface of the heat absorbing glass, which has been coated with the zirconium oxynitride film, and pressed under the pressure of 15 kg/cm 2 at temperature of 120° C. in an autoclave. An optical characteristics of a laminated glass thus obtained is also shown in Table 1.
Next, an antenna conductor made of copper is secured to the outer surface of the transparent glass, and various characteristics of the laminated glass: the transmissivity of visible light, the transmissivity of sun light, the reflectivity of visible light, and the difference with a filmless laminated-glass on the Hunter plane are examined and also shown is Table 1.
Moreover, the electromagnetic-wave transmission characteristic of the laminated glass is measured within a range of 1 kHz-1.575 GHz by a method proposed by "Kansai Denshikogyo Shinko Center (denoted by KEC)", and shown in Table 2.
TABLE 2______________________________________Transmissivity Reduction ofElectromagnetic Waves (dB) 880 MHz 1.575 GHz 1 90 400 MHz for for kHz MHz for TV telephone satellite for for broad- communi- communi-Frequency AM FM casting cations cations______________________________________Example 1 ±0 ±0 ±0 ±0 ±0Example 2 ±0 ±0 ±0 ±0 -0.01Example 3 ±0 ±0 ±0 ±0 ±0Example 4 ±0 ±0 ±0 ±0 ±0Example 5 ±0 ±0 ±0 ±0 ±0Example 6 ±0 ±0 ±0 ±0 ±0Comp. Ex. 1 ±0 ±0 ±0 ±0 ±0Comp. Ex. 2 ±0 ±0 ±0 ±0 ±0Comp. Ex. 3 ±0 ±0 ±0 ±0 ±0______________________________________
It will be seen that is no sensitivity reduction, if the heat-ray intercepting film is used.
EXAMPLE 2
In lieu of metallic zirconium, metallic titanium is used for the target of a magnetron sputtering-device, and by the same method as that used in Example 1 except supplying a mixed gas having a ratio of 100 cc of argon to 500 cc of nitrogen, a film having a thickness of 7 nm is formed on the concave surface of a heat absorbing glass and one surface of a 10 cm square of the glass. The film of the 10 cm square is examined by an ESCA analyser and it becomes clear that the film contains oxygen and is of titanium oxynitride. A result of its quantitative analysis is shown in Table 1. Oxygen in the film seems to have been supplied from the gas remained in the vacuum chamber before the sputtering is performed, or from the surface of the heat absorbing glass. It is noted that the sheet resistivity of the film is 1.5 kΩ/□.
A laminated glass with an antenna conductor is made by the same method as that used in Example 1, and its various characteristics are examined and shown in Tables 1 and 2.
EXAMPLE 3
In lieu of metallic zirconium, metallic chromium is used for the target of a magnetron sputtering-device, and by the same method as that used in Example 1 except supplying a mixed gas having a ratio of 100 cc of argon to 300 cc of nitrogen, a film having a thickness of 6 nm is formed on the concave surface of a heat absorbing glass and one surface of a 10 cm square of the glass. The film of the 10 cm square is examined by an ESCA analyser and it becomes clear that the film contains oxygen and is of chromium oxynitride. A result of its quantitative analysis is shown in Table 1. Oxygen in the film seems to have been supplied from the gas remained in the vacuum chamber before the sputtering is performed, or form the surface of the heat absorbing glass. It is noted that the sheet resistivity of the film is 50 kΩ/□.
A laminated glass with an antenna conductor is made by the same method as that used in Example 1, and its various characteristics are examined and shown in Tables 1 and 2.
EXAMPLE 4
By the same method as that used in Example 1 except supplying a mixed gas having a ratio of 100 cc of argon to 230 cc of nitrogen to a magnetron sputtering device, a film having a thickness of 9 nm is formed on the concave surface of a heat absorbing glass and one surface of a 10 cm square of the glass. The film of the 10 cm square is examined by an ESCA analyser and it becomes clear that the film contains oxygen and is of zirconium oxynitride. A result of its quantitative analysis is shown in Table 1. Oxygen in the film seems to have been supplied from the gas remained in the vacuum chamber before the sputtering is performed, or from the surface of the heat absorbing glass. It is noted that the sheet resistivity of the film is 80 kΩ/□.
A laminated glass with an antenna conductor is made by the same method as that used in Example 1, and its various characteristics are examined and shown in Tables 1 and 2.
EXAMPLE 5
In lieu of metallic zirconium, metallic titanium is used for the target of a magnetron sputtering-device, and by the same method as that used in Example 1 except supplying a mixed gas having a ratio of 100 cc of argon to 300 cc of nitrogen to 1 cc of oxygen, a film having a thickness of 8 nm is formed on the concave surface of a heat absorbing glass and one surface of a 10 cm square of the glass. The film of the 10 cm square is examined by an ESCA analyser and it becomes clear that the film contains oxygen and is of titanium oxynitride. A result of its quantitative analysis is shown in Table 1. It is noted that the sheet resistivity of the film is 50 kΩ/□.
A laminated glass with an antenna conductor is made by the same method as that used in Example 1, and its various characteristics are examined and shown in Tables 1 and 2.
EXAMPLE 6
In lieu of metallic zirconium, metallic chromium is used for the target of a magnetron sputtering-device, and by the same method as that used in Example 1 except supplying a mixed gas having a ratio of 100 cc of argon to 300 cc of nitrogen to 20 cc of oxygen, a film having a thickness of 7 nm is formed on the concave surface of a heat absorbing glass and one surface of a 10 cm square of the glass. The film of the 10 cm square is examined by an ESCA analyser and it becomes clear that the film contains oxygen and is of chromium oxynitride. A result of its quantitative analysis is shown in Table 1. It is noted that the sheet resistivity of the film is 500 kΩ/□.
A laminated glass with an antenna conductor is made by the same method as that used in Example 1, and its various characteristics are examined and shown in Tables 1 and 2.
COMPARATIVE EXAMPLE 1
By the same method as that used in Example 1 except supplying a mixed gas having a ratio of 100 cc of argon to 300 cc of nitrogen, a film having a thickness of 11 nm is formed on the concave surface of a heat absorbing glass and one surface of a 10 cm square of the glass. The film of the 10 cm square is examined by an ESCA analyser and it becomes clear that the film contains oxygen and is of zirconium oxynitride. A result of its quantitative analysis is shown in Table 1. Oxygen in the film seems to have been supplied from the gas remained in the vacuum chamber before the sputtering is performed, or from the surface of the heat absorbing glass. It is noted that the sheet resistivity of the film is 500 kΩ/□.
A laminated glass with an antenna conductor is made by the same method as that used in Example 1, and its various characteristics are examined and shown in Tables 1 and 2.
COMPARATIVE EXAMPLE 2
In lieu of metallic zirconium, metallic titanium is used for the target of a magnetron sputtering-device, and by the same method as that used in Example 1 except supplying a mixed gas having a ratio of 100 cc of argon to 300 cc of nitrogen to 30 cc of oxygen, a film having a thickness of 10 nm is formed on the concave surface of a heat absorbing glass and one surface of a 10 cm square of the glass. The film of the 10 cm square is examined by an ESCA analyser and it becomes clear that the film contains oxygen and is of titanium oxynitride. A result of its quantitative analysis is shown in Table 1. It is noted that the sheet resistivity of the film is 100 kΩ/□.
A laminated glass with an antenna conductor is made by the same method as that used in Example 1, and its various characteristics are examined and shown in Tables 1 and 2.
COMPARATIVE EXAMPLE 3
In lieu of metallic zirconium, metallic chromium is used for the target of a magnetron sputtering-device, and by the same method as that used in Example 1 except supplying a mixed gas having a ratio of 100 cc of argon to 300 cc of nitrogen to 100 cc of oxygen, a film having a thickness of 9 nm is formed on the concave surface of a heat absorbing glass and one surface of a 10 cm square of the glass. The film of the 10 cm square is examined by an ESCA analyser and it becomes clear that the film contains oxygen and is of chromium oxynitride. A result of its quantitative analysis is shown in Table 1. It is noted that the sheet resistivity of the film is 2 MΩ/□.
A laminated glass with an antenna conductor is made by the same method as that used in Example 1, and its various characteristics are examined and shown in Tables 1 and 2.
It will be seen that the respective laminated glasses disclosed in Examples 1-6 can transmit 70% or more of visible light, and have such characteristics that the respective differences Δa and Δb of the coordinates of the Hunter chromaticity plane between the laminated glasses disclosed in Example 1-6 and the laminated glasses having no heat-ray intercepting film are less than 5, so that the heat-ray intercepting film scarcely influences the color of the laminated glass. Further, it will be seen that the respective laminated glasses with antenna conductors disclosed in Examples 1-6 have the radio-waves transmitting characteristics similar to those having no heat-ray intercepting film.
Having described illustrative embodiments of this invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to that precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims. | In an automotive window glass having a pair transparent sheet glasses that are stuck to each other with a transparent resin film, the inner surface of one of the pair of sheet glasses, which faces the transparent resin film, is coated with a heat-ray intercepting film that is composed of any one of the following chemical formulas whose atomic ratios are defined.
(A) ZrN x O y : 0.5≦x≦0.8, and 0.8≦x+y≦1.2
(B) TiN x O y : 0.2≦y≦0.8, and 1.4≦x+y≦1.8
(C) CrN x O y : 0.1≦y≦0.8, and 1.4≦x+y≦1.8 | 8 |
This invention relates to outdrives for boats having partially immersed surface piercing propellers. More particularly, a high speed boat is provided with a surface piercing propeller enclosed within an inverted shroud which effectively defines a channel isolating the propulsion effects of the outdrive from extraneous torques common in surface piercing propeller outdrives. Moreover, an overlying plate improves propeller performance on the departure portion of the propeller blading from the partially immersed propeller.
It will be understood that the outdrive disclosed herein is applicable to all planing hulls—usually proceeding at speeds in excess of 18 mph. This disclosure relates to patrol boats, yachts, mega yachts, and so-called speed boats. Regarding ski boats, it is to be understood that the outdrive herein generates a “rooster tail”, a stream of airborne elevated water propelled by the propeller immediately astern of the outdrive. For that reason, the outdrive is not generally acceptable to ski boats.
In the following discussions, testing of the outdrive will be referred to high horsepower (4,000 hp), high speed drives (160 mph speed with propeller at 6,000 to 7,000 rpm). These powers and speeds have been used for the testing of the drive. The principles set forth here are applicable at much lower powers and speeds so long as a partially immersed propeller is utilized with a planing hull at speeds in excess of 18 mph.
BACKGROUND OF THE INVENTION
In my Arneson U.S. Pat. No. 5,667,415, there is disclosed a surface piercing propeller enclosed within a metal shroud. The shroud extends over the top of the surface piercing propeller in all embodiments illustrated.
In Arneson U.S. Pat. No. 5,667,415, the water churned upwardly by the rotation of the propeller is deflected by the overlying shroud. The interaction of the overlying shroud with the blade tends to reduce the turbulence overlying the propeller. The instabilities of the boat arising from stern lift and bow immersion of the outdrive propeller are substantially reduced. Moreover, the operator finds it much easier to operate the controls of the boat since the overlying shroud acts as a partial barrier for lateral movements of the water which tend to cause the propeller to “walk” to one side of the vessel, exerting a turning force on the boat relative to the water.
The elimination of the instabilities associated with the shroud thereon clearly utilizes the positions of the inner surfaces of the shroud. The shroud is typically far enough away from the plane of rotation of propeller so as to prevent interference by the shroud to the rotation of the propeller itself as well as the shroud being drawn into the propeller. The inner surfaces of the shroud members also contribute to keeping the center shaft thrust direction stable so that there is reduced tendency for the propeller to lift out of the water and cause the operator of the boat to fight the steering and trim gears of the boat. The propeller configuration is different from standard propeller units. The propeller is smaller in diameter with wide thick blade tips that make it very strong and efficient. This allows the boat to get on plane quickly and with ease and maintains the achieved plane even when the rpms of the system are decreased (conventional boats tend to fall off plane when this occurs).
Discovery
I routinely have conducted extensive testing of outdrives in San Francisco Bay and elsewhere. As a result of this extensive testing, and through careful examination of a number test models—exceeding 100 in the last 5 years, I have made several important discoveries. The reader will understand that discovery can constitute invention by itself. More often, discoveries lead to the definition of problems to be solved. Once the problems are identified, further work can lead to the solution of those problems. Accordingly, I claim invention relative to the following discoveries, identification of problems, as well as to the solution to those problems.
First, I have discovered that the propeller characteristics of an outdrive propeller proceeding through the water at high speed are surprising and not obvious, even after thousands of hours of testing. In order to understand these discoveries, it is necessary to review the fundamentals of out drives.
A typical out drive trails the transom of a high speed planing hull. The outdrive propeller is typically immersed below the surface of the water from the center of rotation of the propeller to immerse just the lower half of the propeller within the water, presuming that the water is undisturbed. The shaft of the propeller extends from the transom downward at an angle with respect to the surface of the undisturbed water when the high speed planing hull is on plane. This has the beneficial result of keeping the most of the shaft of the outdrive out of the water. Typically, this angle can be from 6° to 12°. I will use 6° in the following examples.
The shaft of typical outdrive is typically of large diameter. It includes an outer tubular housing and an inner rotating shaft to supply rotational power to the propeller. Typically, the driving shaft is supplied with two sets of bearings. A first bearing adjacent is a universal joint on the shaft with the universal joint enabling the shaft to be “steered.” The second bearing is immediate the propeller at the distal end of the shaft from the boat. Having the shaft extend from the transom of the boat, downward at an angle of 6° to 12° from the horizontal, the major part of the shaft and surrounding tubular member is kept from having to be dragged through the water. This saves considerable friction with respect to the water and this angular disposition of outdrives is universally used.
In the following description, I am going to use the definition “working surface” to describe an arbitrarily selected portion of a propeller blade. I will select this arbitrary “working surface” by measuring radially outward of the blade of a propeller, here a 14 inch diameter propeller. The radial distance that I will choose is 5 inches. I will take measurement of the angle of the working surface tangent to the rotation of the propeller.
The reader will understand the reason for this arbitrary definition. Specifically, propeller blades have changing working blade angles from the hub of the propeller to the extremity of the blades. In the usual case, the pitch is high adjacent the hub and gradually decreases as that pitch is measured radially outward. By having a “working surface” (pitch chosen on an arbitrary radial tangent to the direction of propeller rotation), it is possible to generate a convenient working definition of propeller pitch in angle with respect to the shaft. Using this definition, some of the working principles of this invention can be more easily understood.
I have discovered that the 6° downward disposition of the outdrive shaft has the effect of producing variable pitch propeller blading on opposite sides of the partially immersed propeller! Specifically, this may be seen by taking a representative “working surface” on the surface of a propeller. Say on a 14 inch diameter propeller, this chosen “working surface” happens to be in the middle of a propeller blade at a distance of 5 inches of radius from the center of rotation of a propeller having a 7 inch radius (or 14 inch diameter). Placing a level device along the “working surface” tangent to the direction of propeller rotation and measuring the angle of the “working surface” with respect to the outdrive shaft will yield a constant angle of the working surface with respect to the shaft. Say for example this angle is 54°. So at any position of rotation of the “working surface” with respect to the shaft, this angle will always be the same, that is 54° with respect to a plane including the axis of the drive shaft of the propeller.
But everyone forgets that the propeller shaft itself is at an angle! Say that angle is 6° with respect to the horizontal when the boat is planing at high speed. I have discovered that this produces variable propeller pitch on opposite horizontal sides of the propeller! As these variable propeller pitches are integral to the shrouding that I place around my improved outdrive, the variable pitches must be understood.
As is well known, most single propellers rotate counterclockwise following the well known “right hand rule.” By extending the right hand thumb in the direction of the propeller shaft, the fingers when naturally curled give the direction of rotation of the propeller. Where two propellers are used, one propeller rotates counterclockwise and the other propeller clockwise. And since both type of propellers are always a possibility in an outdrive propeller, I choose to talk about the working surfaces of the propeller entering the water and the working surfaces of the propeller leaving the water, regardless of whether the propeller right or left hand rotation.
As will be shortly developed, the entry pitch of the working surface (angle of attack with respect to the passing undisturbed water) is increased upon entry into the water by the angle of the shaft with respect to the water. Similarly, the departure pitch of the working surface is decreased upon departure from the water by the angle of the shaft with respect to the water. This discovery is an important consideration in the design that follows.
Consider the case of the entry pitch of the working surface. As we have previously developed, the working surface has a 54° angle with respect to the propeller shaft. But the propeller shaft is inclined at 6°. Adding this 6° to 54°, the angle of attack of the entry pitch of the working surface with respect to the undisturbed water though which the propeller passes upon entry into the undisturbed water level now becomes 60°!
Consider the case of the departure pitch of the working surface. Again the working surface has a 54° angle with respect to the propeller shaft. But the propeller shaft is inclined at 6°. Subtracting this 6° from 54°, the angle of attack of the entry pitch of the working surface with respect to the undisturbed water through which the propeller blade passes upon departure from the undisturbed water level now becomes 48°!
The important thing to understand, is that with an outdrive having shaft inclined from the horizontal by a small angle (here 6°), the entry pitch of any working surface on a blade is higher that the departure pitch of any working surface on the blade by the value of the shaft inclination.
Now let us talk about propeller “pitch” in general.
Where one wants rapid acceleration and high propeller output power, low pitches on propellers are desirable. For example, tug boat propellers have low pitch so that large vessels may be slowly moved. Similarly, sail boat auxiliary propellers have low pitch so that the boats may maneuver in adverse weather conditions (i.e. keeping off the rocks in heavy weather). Low pitch propellers are not intended for high speed.
Where one wants high speed, high pitches are desirable. For example, racing boat propellers have high pitch so that the racing boat can proceed at high speed. High pitch propellers are not intended for low speed.
Now let us talk about the practical effect of the pitch change in the partially immersed outdrive propeller. The entry half of the propeller has higher pitch than the departure half the propeller! So at low speed and upon acceleration, the departure pitch will be more ideal. Upon reaching higher speed, the entry pitch of the propeller will be more ideal.
It will be understood that the propellers I use in this disclosed outdrive rotate at high power and high speed; for example all of the applicable testing for this invention has been accomplished in a twin hull boat having a 4000 Hp Lycoming Gas Turbine Engine with propeller rotating speeds of 6,000 to 7,000 rpms. Propellers having mechanically variable pitches are not practicable.
Again, the reader should not confuse my testing of this outdrive with those minimal conditions necessary to make the outdrive operable. As I have emphasized, any planing hull proceeding at more than 18 mph will suffice. Further, power expended to do this can be relatively minimal. All that is needed is sufficient power to make the boat hull plane.
Having discussed my discovery of the variable pitch of an outdrive propeller, discussion of my discoveries about the disturbance of water by a propeller proceeding through the water at high speed now become relevant. In summary, I have discovered that where a boat is proceeding at high speed—say 160 mph, standing water is disturbed before the blade of the propeller passes through the standing water. In other words, there is a disturbance in advance of blade entry to the surface of the water! There is a well known disturbance after the blade passes through the water; any person standing at the stern of a propeller driven vessel and observing its wake recognizes this disturbance. It is not well known that disturbance occurs in the direction of boat travel in advance of the passage of the propeller blades through the water!
First, it may well be that shock wave transmit in water faster than the high speed (e.g. 160 mph) passage of the boat.
Second, the variable pitch phenomena related to outdrives also has an effect. Consider the following.
If a propeller is pulled through the water without rotation, the “windage” of the propeller will cause the propeller to rotate. This is a well known phenomena for sailors repairing large engines at sea on ships underway. Specifically, the shaft of the engine being repaired must be locked, and ship moved at slow speed to maintain steerage, otherwise the windage of the propeller will cause the engine under repair to rotate, creating an extraordinarily dangerous condition.
Now consider the case where the propeller is rotated at a speed which is “neutral” to the rate of the passing water. Other than displacement effects, the propeller will neither have windage nor a propulsive force.
In the usual case, the propeller is rotated to propel water at a considerably faster speed than actual passage of the boat through the water. The propeller has slippage with respect to the passing water that is essential to its propelling effect. Anyone who has observed the wake of a propeller propelled ship is familiar with this result.
Now consider the case of the outdrive of this invention. The entry side of the propeller has a higher pitch, driving the water at higher speed. The departure side of the propeller has lower pitch, driving the water at lower speed. In actual practical effect, both pitches will considerably exceed the rate of passage of the boat through the water. For example, where the boat is proceeding through the water at 160 mph, both the entry high pitch side of the propeller and the departure low pitch side of the propeller will drive water at speeds exceeding the 160 mile per hour speed of the boat.
But there will be another surprising effect. When the entry side of the propeller is compared to the departure side of the propeller; water build up in advance of the departure side of the propeller will be more pronounced than water build up in advance of the entry side of the propeller!
The reason for this water build up differential is directly related to the variable pitch between the departure and entry sides of the propeller. Specifically, since the departure side has lower pitch and moves water at the propeller more slowly, water buildup in advance of the departure of the partially immersed propeller blade will be greater. Similarly, since the entry side has higher pitch and moves water at the propeller more quickly, water buildup in advance of the entry of the partially immersed propeller blade will be lesser. As will hereafter be understood, I use the greater buildup of water on the departure side of the propeller to advantage. Specifically, I place a horizontal barrier at approximately two thirds (⅔) of the propeller radius directly overlying the departure side of the partially immersed propeller. This has the effect of keeping the low pitch departure side of the propeller immersed in water for more efficient propulsion.
Plates overlying propellers used in the prior art are known. So-called “cavitation” plates are an example. These plates, used for example over outboard propellers, prevent water “flashing” into steam (cavitation). As distinguished from my plate, these plates are over an entirely immersed propeller. In what follows, I show plates under to the top portion of the partially immersed propeller.
Further, I have used plates on outdrives on shrouds or fins, these plates being over the upper two thirds (⅔) of a propeller. However, these plates have been parallel to the shaft, and never parallel to the plane of the undisturbed water. These plates have the effect of directing reverse water jets at and over the transom of the boat to which they are attached, especially during coming up to speed or decelerating from speed.
Further, the plates have been separated by several inches (in the order of three to four [3 to 4] inches) in advance of the propeller. Plates with this spacing cannot cooperate with the accumulation of water in advance of the departure side of the propeller. Water in the gap between the propeller and plate is not controlled and cannot provide the improved propulsion of this disclosure.
I have further discovered that inversion of the shroud from the preferred embodiments shown in my Arneson U.S. Pat. No. 5,667,415 produces superior results. Specifically, I use an inverted or “upside down” shroud. The inverted shroud defines an enclosed operating channel for the surface piercing portion of the propeller which isolates the partially immersed propeller from imparting unwanted torques to high speed hulls driven by the disclosed outdrive. Stern uplift with bow immersion is avoided. Further, crawling or “helm” exerted to one or the other side of the boat is substantially reduced.
The “upside down” shroud renders the direction of propeller rotation essentially irrelevant as it forms a separate and isolated chamber from the remainder of the water that the boat is passing through. For example, whether a so-called “right hand propeller” or a “left hand propeller” is utilized is irrelevant. Further, the slope of the wake where propeller immersion occurs is not as important. The disclosed shroud has the effect of isolating what might otherwise undesired torques on the vessel propelled by my outdrive.
BRIEF SUMMARY OF THE INVENTION
A shrouded outdrive propels a high speed boat having a hull for high speed passage through water. The hull has at least one bow at the forward end and at least one transom at the stern. A tubular propeller shaft extends at a small angle (6° to 12°) from the boat transom into the water with a shaft within the tubular propeller shaft. A propeller is mounted to the shaft for partial immersion in the water whereby a lower portion of the propeller passes below and into the water during high speed floating passage of the boat and a upper portion of the propeller passes above the water during high speed floating passage of the boat. A shroud is disposed about the propeller with the shroud being disposed below the water and adjacent the propeller. A mount for the shroud holds the shroud around the propeller whereby the propeller operates within a shroud enclosed channel during high speed passage of the boat through the water. A plate horizontal to the undisturbed passing water surface is disposed overlying the departure side of the propeller at a radial distance of about two thirds (⅔) of the radius of the propeller. This plate immediately abuts the departure blading of the propeller and assures immersion of the lower pitch departures side of the partially immersed propeller in water for more efficient propulsion. Embodiments are disclosed where the plate is utilized as the necessary support for the shroud. Additionally, both the shroud and the plate can have small angular variations with respect to the surface of the undisturbed surface through which the high speed hull passes.
An advantage of the inverted shroud is that it effectively defines a channel in the water in which the partially immersed propeller can operate. Forces tending to cause the partially immersed propeller to “walk” or steer the boat by causing “helm” (steering bias) are controlled. Specifically, the shroud created channel isolates the outdrive from reacting with the water to either side of the propeller.
An additional advantage of the inverted shroud is that it provides a smooth acceleration of the watercraft to cruising speed. It is not accompanied by propeller spinning at high speed with propeller cavitation to the surrounding water. Further, at low planing speeds, the outdrive tends to maintain planing and does not allow the driven hull to “fall” off of the plane and into the water in a displacement mode.
Further, the inverted shroud can itself be adjusted in pitch, either with the angle of the outdrive or independent of the angle of the outdrive. This adjustment in pitch of the shroud can trim lifting forces on the hull of the high speed boat being propelled by the outdrive. In the usual case, adjustments in shroud trim will be made to avoid undue stern lift and reactive pressure pushing the bow of the high speed boat into the water.
An advantage of the plate overlying the departure side of the partially immersed outdrive propeller blading is that it confines water over the departure blading at a level well above the “undisturbed” water line. Propeller blades, departing a plane above the normal water line, pass through a layer of water that is elevated above the plane of where the water would be, if it was undisturbed. In such passage, it is possible for the “lower pitch” departure blading to exert a propelling effect on the water.
An advantage of this propelling effect of the low pitch portion of the departure propeller blading is two-fold. First, this portion of the blading accounts for the superior acceleration characteristics of this outdrive design. When the boat is accelerating, the low pitch of the departure blading apparently adds acceleration. I rate this acceleration extraordinarily high over many comparable designs that I have tested.
Second, even when the boat is at full (high) speed, I find that the “low pitch” portion of the propeller is much more efficiently utilized. Being that the low pitch portion of the propeller has an increased “dwell time” in the passing water, the propulsion contribution of the low pitch departure blading is increased by the overlying plate.
It will also be understood, that this overlying plate operates parallel to the surface of the undisturbed water. Slight angles of inclination (much less than the 6° to 12° inclination of the propeller shaft) can be applied to the plate. These angles of inclination will be independent of the shaft and the shroud and again can be used to fine tune forces tending to either lift or depress the outdrive at the stern of the boat.
A further advantage of both the plate and the inverted shroud is that it provides the propeller with protection. While debris can conceivably be introduced into the interstices between the propeller, plate and inverted shroud, in the usual case debris will be deflected. In most cases, debris not deflected will be pulverized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of the boat illustrated in FIG. 1 of my Arneson U.S. Pat. No. 5,667,415 entitled “Marine Outdrive with Surface Piercing Propeller and Stabilizing Shroud,” this boat now being fitted with the outdrive of this disclosure;
FIG. 2 is a schematic perspective view of an outdrive illustrating propeller blading and a working surface of that propeller blading relative to the inclined outdrive shaft, the entry portion of the propeller blading relative to the undisturbed water, and the departure portion of the propeller blading relative to the undisturbed water, with the increased water level on the departure portion of the propeller blading being schematically shown;
FIG. 3A is a perspective taken looking toward the transom of a boat having an outdrive according to this invention illustrating the mounting with a flat plate, five bladed propeller, and hydraulic cylinder support for steering the outdrive;
FIG. 3B is an end elevation of a propeller with underlying shroud shown in FIG. 3A showing the propeller with the departing blades raising the water level in advance of the passage of the propeller with the overlying plate parallel to the surface of the water confining the water below the departing blades to enable efficient drive from the departing blade side of the propeller;
FIG. 3C is a side elevation along lines 3 C- 3 C of FIG. 3B illustrating the immediate proximity of the plate terminating adjacent the edge of departing blades of the propeller;
FIG. 4 is a perspective view of the outdrive of FIGS. 3A , 3 B and 3 C illustrating independent angular adjustment of the shroud relative to the rest of the outdrive;
FIG. 5A is an embodiment of the outdrive with the inverted shroud omitted and only the plate producing the improved propulsion of this invention;
FIG. 5B illustrates the inverted shroud with a rectilinear profile; and,
FIG. 5C illustrates the inverted shroud with one side curved and the opposite side linear.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , high speed planing hull H having transom T has outdrive O. Hull H passes over water having upper surface 10 . Outdrive O has partially immersed propeller P surrounded by shroud S which below, around and adjacent the propeller.
Referring further to FIG. 1 , the most important thing to note is the angle between the plane of upper surface 10 of the water and centerline 14 of outdrive O shaft. Specifically, outdrive O has an angle of 6° with respect to upper surface 10 . This angle can vary. In a wide range, this angle can be from 3° to 12°. In a narrower range, this angle can be from 4° to 9°. Here it is illustrated at the preferred angle of about 6°. Further, it will be understood that these angles are taken when the hull H is underway in a planing disposition at air speeds in the range of 30 mph to 160 mph. I avoid air speeds above 160 mph because of the danger of hull H becoming airborne.
Hull H is on the order of 50 feet in length with a displacement of 8,000 pounds. It is driven by a Lycoming gas turbine engine outputting 1,250 HP. At speeds approaching 160 mph, propeller P turns at speeds in the range of 6,000 to 7,000 rpms. Propeller P is typically of modified construction. Specifically, I buy a 22 inch propeller manufactured by the Rolla SP Propellers SA of Balerna, Switzerland. Thereafter, for the application here, I have the blades truncated so that they are about 14 inches in diameter. Over conventional outdrives, it will be understood that the blading here illustrated is truncated; the propeller shape is accurately represented in the attached drawings.
Brief reference will now be made to FIGS. 3A , 3 B and 3 C. Referring to FIG. 3C , hull H is shown with outdrive O protruding from transom T. A tubular propeller shaft 20 has an inner drive shaft 22 . Drive shaft 22 extends between universal joint 24 adjacent transom T and propeller bearing 26 adjacent propeller P. Drive shaft 22 is co-axial to centerline 14 .
Referring to FIGS. 3A and 3B , steering and adjustment of outdrive O relative to water can be understood. Hydraulic steering cylinders 30 are illustrated with transom T being omitted. Specifically, port steering cylinder 31 , center cylinder 32 , and starboard steering cylinder 33 are illustrated. Remembering that drive shaft 22 is on universal joint 24 , it can be easily understood that by using hydraulic steering cylinder 30 , both the adjustment of outdrive O in angle to water surface 14 and side-to-side steering angle can easily occur. Since the propeller and steering are essentially in the prior art, further description will not be provided.
Having set forth the general configuration, attention now can be turned to FIG. 2 . With FIG. 2 , I will explain the variation of propeller pitch with respect to the propeller P.
Outdrive propeller P is typically immersed below the surface 10 of the water from the center of rotation 30 of the propeller to immerse just the lower half of the propeller within the water, presuming that the water is undisturbed. Shaft 22 of the propeller extends from the transom downward at a 6° angle with respect to surface 10 of the undisturbed water when the high speed planing hull is on plane. This has the beneficial result of keeping the most of the shaft 20 , 22 of the outdrive out of the water. Typically, this angle can be from 6° to 12°. I will use 6° in the following examples.
The shaft of typical outdrive is typically of large diameter, here approximately 5 inches. It includes an outer tubular housing 20 and an inner rotating shaft 22 to supply rotational power to propeller P. Having the shaft extend from the transom of the boat, downward at an angle of 6° to 12° from the horizontal, the major part of the shaft and surrounding tubular member is kept from having to be dragged through the water. This saves considerable friction with respect to the water and this angular disposition of outdrives is universally used.
The propeller that I prefer to use is a 22 inch Rolla Propeller manufactured by the Rolla SP Propellers SA of Balerna, Switzerland. The blade is truncated to my order so that the original 22 inch diameter ends up being 15 inches. The propeller can be generically described as a “cleaver style” propeller. While other propellers will do, this propeller constitutes my preferred design.
In the following description, I am going to use the definition “working surface” to describe an arbitrarily selected portion of a propeller blade. I will select this arbitrary “working surface” 30 by measure radially outward of the blade of a propeller, here a 15 inch diameter propeller. The radial distance that I will choose is 5 inches. I will take measurement of the angle of the working surface tangent to the rotation of the propeller and with respect to the plane of the upper surface of the water including surface 10 .
The reader will understand the reason for this arbitrary definition. Specifically, propeller blades have changing working blade angles from the hub of the propeller to the extremity of the blades. In the usual case, the pitch is high adjacent the hub and gradually decreases as that pitch is measured radially outward. By having a “working surface” 30 (pitch chosen on an arbitrary radial tangent to the direction of propeller rotation), it is possible to generate a convenient working definition of propeller pitch in angle with respect to the shaft. Using this definition, some of the working principles of this invention can be more easily understood.
I have discovered that the 6° downward disposition of the outdrive shaft has the effect of producing variable pitch propeller blading on opposite sides of the partially immersed propeller! Specifically, this may be seen by taking a representative “working surface” 30 on the surface of a propeller. Say on a 14 inch diameter propeller, this chosen “working surface” 30 happens to be in the middle of a propeller blade at a distance of 5 inches of radius from the center of rotation of a propeller having a 7 inch radius (or 14 inch diameter). Placing a level device along the “working surface” tangent to the direction of propeller rotation and measuring the angle of the “working surface” with respect to the outdrive shaft will yield a constant angle of the working surface with respect to the shaft. Say for example this angle is 54°. So at any position of rotation of the “working surface” 30 with respect to the shaft, this angle will always be the same, that is 54° with respect to a plane including the axis of the drive shaft of the propeller.
But everyone forgets that the propeller shaft itself is at an angle! That angle is illustrated here at 6° with respect to the plane of the undisturbed water when the boat is planing at high speed. I have discovered that this produces variable propeller pitch on opposite horizontal sides of the propeller! As these variable propeller pitches are integral to the shrouding that I place around my improved outdrive, the variable pitches must be understood.
As is well known, most single propellers rotate counterclockwise following the well known “right hand rule.” By extending the right hand thumb in the direction of the propeller shaft, the fingers when naturally curled give the direction of rotation of the propeller. Thus it will be understood that in FIG. 2 , I illustrate the more common right hand propeller.
Where two propellers are used, one propeller rotates counterclockwise and the other propeller clockwise. And since both type of propellers are always a possibility in an outdrive propeller, I choose to talk about the working surfaces 30 of the propeller entering the water and the working surfaces 30 of the propeller leaving the water, regardless of whether the propeller right or left hand rotation.
I have found the entry pitch of the working surface (angle of attack with respect to the plane of the passing undisturbed water) is increased upon entry into the water by the angle of the shaft with respect to the water. Similarly, the departure pitch of the working surface is decreased upon departure from the water by the angle of the shaft with respect to the water. This discovery is an important consideration in the design that follows.
Referring to FIG. 2 , consider the case of the entry pitch of the working surface 30 , this entry working surface 30 being toward the viewer in the perspective view of FIG. 2 . As we have previously developed, the working surface has a 54° angle with respect to a plane including the propeller shaft. But the propeller shaft is inclined at 6°. Adding this 6° to 54°, the angle of attack of the entry pitch of the working surface with respect to the undisturbed water though which the propeller passes upon entry into the undisturbed water level now becomes 60°! This is illustrated in FIG. 2 .
Consider the case of the departure pitch of the working surface 30 . This working surface 32 is away from the viewer in the perspective view of FIG. 2 . Again the working surface has a 54° angle with respect to the propeller shaft. But the propeller shaft is inclined at 6°. Subtracting this 6° from 54°, the angle of attack of the entry pitch of the working surface with respect to the undisturbed water through which the propeller blade passes upon departure from the undisturbed water level now becomes 48°!
The important thing to understand, is that with an outdrive having shaft inclined from the horizontal by a small angle (here 6°), the entry pitch of any working surface on a blade is higher that the departure pitch of any working surface on the blade by the value of the shaft inclination.
Now let us talk about the practical effect of the pitch change in the partially immersed outdrive propeller P. The entry half 35 of propeller P has higher pitch than the departure half 36 of the propeller! So at low speed and upon acceleration, the departure pitch of departure half 36 will be more ideal. Upon reaching higher speed, the entry pitch of the entry half 35 of propeller P will be more ideal.
Having discussed my discovery of the variable pitch of an outdrive propeller, discussion of my discoveries about the disturbance of water by a propeller proceeding through the water at high speed now become relevant. In summary, I have discovered that where a boat is proceeding at high speed—say 160 mph, standing water is disturbed before the blade of the propeller passes through the standing water. In other words, there is a disturbance in advance of blade entry to the surface of the water! There is a well known disturbance after the blade passes through the water; any person standing at the stern of a propeller driven vessel and observing its wake recognizes this disturbance. It is not well known that disturbance occurs in the direction of boat travel in advance of the passage of the propeller blades through the water!
First, it may well be that shock waves transmit in water faster than the high speed (e.g. 160 mph) passage of the boat.
Second, the variable pitch phenomena related to outdrives also has an effect. Consider the following.
In the usual case, the propeller is rotated to propel water at a considerably faster speed than actual passage of the boat through the water. The propeller has slippage with respect to the passing water that is essential to its propelling effect. Anyone who has observed the wake of a propeller propelled ship is familiar with this result.
Now consider the case of the outdrive of this invention. The entry side of the propeller has a higher pitch, driving the water at higher speed. The departure side of the propeller has lower pitch, driving the water at lower speed. In actual practical effect, both pitches will considerably exceed the rate of passage of the boat through the water. For example, where the boat is proceeding through the water at 160 mph, both the entry high pitch side 35 of the propeller and the departure low pitch side 36 of the propeller will drive water at speeds exceeding the speed of the boat.
But there will be another surprising effect. When the entry side of the propeller is compared to the departure side of the propeller; water build up in advance of the departure side of the propeller will be more pronounced than water build up in advance of the entry side of the propeller! I have illustrated this surface build up by the elevated waterline surface 10 a shown with respect to departure half 36 . Observing this illustration, it will be understood that the drive passes from left to right of the illustrated perspective. It will further be seen that I illustrate this build up well in advance of propeller P.
The reason for this water build up differential is directly related to the variable pitch between the departure and entry sides of the propeller. Specifically, since the departure side has lower pitch and moves water at the propeller more slowly, water buildup in advance of the departure of the partially immersed propeller blade will be greater. Similarly, since the entry side has higher pitch and moves water at the propeller more quickly, water buildup in advance of the entry of the partially immersed propeller blade will be lesser.
As will hereafter be understood with respect to FIGS. 3A , 3 B and 3 C, I use the greater buildup of water on the departure side of the propeller to advantage.
Referring to FIG. 3A , I illustrate in perspective a view of my new shrouded outdrive O. Specifically propeller P has bracket 42 mounted overlying cylindrical propeller shaft 20 . Bracket 42 supports flat plate 40 immediately before propeller P. It will be seen that the underside of plate 40 is roughly parallel with the plane of the upper surface of the undisturbed surface of water which outdrive O should pass through. It will also be noted that plate 40 is above the plane of upper surface 10 of the water.
Regarding this elevated placement of the lower surface of plate 40 , I place a horizontal barrier at approximately two thirds (⅔) of the propeller radius directly overlying the departure side of the partially immersed propeller. This has the effect of keeping the low pitch departure side of the propeller immersed in water for more efficient propulsion.
This effect can be understood upon returning to FIG. 2 . Regarding the departure section 36 of propeller P, it will be remembered that waterline 10 a rises in advance of the passage of outdrive O through the undisturbed water. This rising occurs until the bottom surface of plate 40 is encountered. The rising water is then confined below the surface of plate 40 .
Returning to FIG. 3C and the side elevation there shown, another important aspect of plate 40 can be understood. Specifically, plate 40 terminates immediately ahead of the leading edge of propeller P. By immediately ahead, I use as little a distance as practicable. Separation is only maintained at a sufficient distance to assure that the trailing edge of plate 40 and the leading blade edges of propeller P do not physically interfere and that normal handling of the outdrive O does not bend or deflect either the propeller P or the plate 40 so as to cause interference.
It is important to note that plate 40 has a beneficial effect primarily on the departure side 36 of propeller P; plate 40 has no appreciable effect and is not required on entrance side 35 of plate 40 . Here, however, plate 40 is part of mount 42 holding shroud S around propeller P. Thus, I choose to make plate 40 symmetrical.
Returning to FIGS. 3A and 3B , it will be seen that shroud S is mounted at the side to side extensions 44 from plate 40 . Shroud S is invert and arcuate; it extends below, around and about propeller P. For purposes of boat control, shroud S includes skeg 50 . Skeg 50 supplements the action of shroud S in maintain outdrive O on course through the water without torques being applied to boat steering.
I have found that shroud S being invert, arcuate extending below, around and adjacent partially submersed propeller P has the effect of defining a channel in the water as outdrive passes through that water at high speed. Specifically, shroud S prevents water circulation to the side of propeller P and assures that propeller P only drives water fore and aft of outdrive O. The disposition of a shroud under propeller P is not shown in my Arneson U.S. Pat. No. 5,667,415.
Referring to FIG. 4 , it will be seen that shroud S and plate 40 are pivotal about an axis 60 overlying propeller P (obscured from view). Hydraulic cylinder 63 extends between a first clevis 61 on cylinder 32 and a second clevis 62 on plate 40 . It this way small adjustments can be made to the angle of plate 40 and shroud S. It is to be noted that for purposes of understanding I show a relatively great deflection in angle of plate 40 and shroud S; in actual fact this deflection can be quite small. In the usual case it is utilized to apply trim from the outdrive to the hull, for example by preventing the stern from being unduly lifted due to lift applied at the stern.
The reader will understand that there are two discrete parts to this disclosure. In FIG. 5A we show plate 40 functioning to keep the outgoing blading immersed in water for a greater dwell time in its total rotational cycle. This improves propulsion. It should be noted that I prefer a truncated shroud S for this embodiment that does not surround propeller P. In other words, plate 40 will be operable in the absence of a surrounding shroud S.
Referring to FIG. 5B , it is emphasized that the inverted shroud S can be other than a smooth arc. For example, the shroud S is shown with angles of 100° utilized in squaring the rear elevation of the propeller.
Referring to FIG. 5C , an inverted shroud S is sown having a curvilinear starboard side with a linear port side. Curvilinear starboard side enables outgoing propeller blading to cooperate with shroud S in raising water to plate 40 .
The reader will understand that plate 40 and shroud S will admit of variation. However, so long as plate 40 creates additional dwell time of the departing blades within a passing water stream, the function of plate 40 will be practiced. Further, so long as shroud S provides an isolated channel for operation of the outdrive without extraneous torques being introduced to the propelled hull, this section of the invention will be practiced. | A shrouded outdrive propels a high-speed boat having a hull for high-speed passage through water. The hull has at least one bow at the forward end and at least one transom at the stern. A tubular shaft extends at a small angle (6° to 12°) from the boat transom into the water, and a drive shaft is arranged within the tubular shaft. A propeller is mounted to the drive shaft for partial immersion in the water so that a lower portion of the propeller extends into the water during high-speed floating passage of the boat and a upper portion of the propeller is above the water during high-speed floating passage of the boat. A shroud is arranged about the propeller and is disposed below the water and adjacent the propeller. A mount holds the shroud to form a shroud-enclosed channel during high-speed passage of the boat through the water in which the propeller rotates. A plate horizontal to the undisturbed passing water surface overlies the departure side of the propeller at a radial distance of about two thirds (⅔) of the radius of the propeller. This plate immediately abuts the departure blading of the propeller in the direction of boat movement through the water and assures immersion of the lower pitch departure side of the partially immersed propeller in water for more efficient propulsion. Embodiments are disclosed where the plate is utilized as the necessary support for the shroud. Additionally, both the shroud and the plate can have small angular variations with respect to the surface of the undisturbed surface through which the high-speed hull passes. | 1 |
BACKGROUND OF INVENTION
1. Field of Invention
This invention relates to elastic double-knit fabrics and more particularly to elastic double-faced weft-knit fabrics.
2. Background
It is well-known to knit elastic yarns such as spandex yarns with hard yarns to produce knitted fabrics having a certain amount of "give". Heretofore, elastic double-knit fabrics have been made in one of two ways. One, the elastic yarn is plaited with a hard yarn on the same feed on both the dial and cylinder. Such a fabric is heavy, costly, and requires heat stabilization to obtain a fabric which can be used commercially. Second, it is known from BE-A-704 681 that the fabric weight and cost can be lowered by plaiting the elastic yarn with a hard yarn either on the dial or .cylinder only, and using such a plaited elastic yarn at most during every other course. However, such a fabric still must be heat-set.
It has now been found that, if the elastic yarn is plaited independently on the dial of the first feed and the cylinder of the second feed with independent hard yarns, the above-mentioned difficulties are overcome. In addition, such a new fabric has higher power at a lower elongation. For double-faced double-knit fabrics, a light-weight fabric is now possible; and it does not have to be heat-set prior to use.
SUMMARY OF THE INVENTION
According to the present invention there is provided a process for manufacturing a double-knit fabric from elastic yarns (1) and (3) and hard yarns (2) and (4) by plaiting one elastic yarn (1) with a hard yarn or filament (2) on the dial of a first feed (1), characterized in that two independent elastic yarns (1) and (3) are plaited with independent hard yarns or filaments (2) and (4), and that the second elastic yarn (3) is plaited with a second hard yarn or filament (4) on the cylinder of a second feed (2).
BRIEF DESCRIPTION OF THE DRAWINGS
The drawing diagrammatically illustrates the first six courses of a double knit plain rib fabric produced on a circular knitting machine, with reference numerals corresponding to those provided in parentheses in the claims.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the invention, elastic yarns and hard yarns are knitted so as to provide a double-knit fabric which does not have to be heat-set after knitting. Thus, the final knitted fabric weight and width is obtained on the machine.
The terms "elastic" yarn and "hard" yarn or filament as used herein are well-known in the art. Examples of suitable "elastic" yarns including shirring elastic and various elastane fibers, particularly those sold under the tradename LYCRA. A "hard" yarn is a non-contractible yarn and there is a wide range of such yarns that can be used in this invention, both natural and synthetic. The "hard" yarn(s) or filament(s) used will be selected primarily for the visual appearance and feel of the final fabric. Suitable natural spun yarns are cotton, linen, wool, cashmere, alpaca, silk, mohair, and blends of any of them. Suitable synthetic spun yarns include polyester, polyamide, and viscose. The synthetic yarns can also be blended with natural yarns such as cotton/polyester or wool/polyester. A filament is typically a continuous filament yarn of a synthetic polymer such as a polyester or a polyamide.
The double-knit fabric of the present invention can be knitted on any of the conventional circular knitting machines used for double-knits. These machines and constructions are well-known to those skilled in the art.
As shown in the drawing, in the first, third, and fifth courses, an elastic yarn 1 is fed independently to the cylinder only of a circular knitting machine. The yarn is fed under tension with a hard yarn 2 and plaited with it. In the second fourth and sixth courses, a second elastic yarn 3 is fed under tension to the dial only of a circular knitting machine and is pieced with hard yarn 4. Courses 1 and 2 are repeated for as long as desired to make a plain rib fabric. As stated earlier, the appearance and feel of the fabric can be varied by selecting different hard yarns and by varying the dtex of the yarns used. In addition, different fabric constructions can be prepared by varying the needle selection. Constructions according to the invention will be called the "Meyrinoise Stitch".
The invention can be further illustrated by the following examples:
EXAMPLE 1
A 1/1 plain rib double-knit fabric as shown in the drawing was made on a TERROT 20-gauge circular knitting machine having a 30 inch (76.2 cm) diameter and 2×1872 needles. The elastic yarns independently fed via two separate plaiting feeders (as described in Melliand Textilberichte, vol. 73, no. 10, October 1992, pp. 812-815 (in particular §3.1 and FIG. 7)) to the dial and cylinder of the knitting machine were 78 dtex LYCRA (elastane) and the hard yarns-independently fed with the elastane yarns were 85/1 number metric (Nm) cotton. The hard yarn feed rate was 0.32 m/100 stitches; the tension of the hard yarn was ScN and of the elastic yarn 6 cN. The elongation of the elastic yarn at these machine settings was 200%. The resulting plain rib fabric contained 12% by weight elastane and 88% by weight cotton, had a finished weight of 158 g/m 2 , and had a finished width of 170 cm. This fabric was ready for standard dyeing and finishing conditions used for hard yarns without heat-setting.
EXAMPLE 2
Using the same circular knitting machine as in Example 1, except set for an interlock construction, two 22 dtex elastane yarns and the same cotton yarns were fed independently as shown in the drawing. The hard yarn feed rate was 0.20 m/100 stitches; the tension of the hard yarn was 5 cN and of the elastic yarn 3 cN. The elongation of the elastic yarn at these machine settings was 200%. The resulting interlock fabric contained 4% by weight elastane and 96% by weight cotton, had a finished weight of 244 g/m 2 , and had a finished width of 96 cm. This fabric was ready for standard dyeing and finishing conditions used for hard yarns without heat-setting. | A process for making a double-knit fabric from elastic yarns and hard yarns and the double-knit fabric product. The double-knit fabric does not have to be heat-set prior to use. | 3 |
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a device to train birds in a cage to talk. The device is attached to the bird cage and repeats a stored message at specified regular intervals.
BACKGROUND OF THE INVENTION
People have enjoyed birds as pets for centuries. Birds that could mimic human speech or "talk" have been the most prized as pets. Being able to train a bird to talk not only allows it to be more enjoyable as a pet but also increases its monetary value significantly.
For a bird to learn to talk it must be exposed to human speech. While a very small number of very talented birds can learn to talk from being exposed to normal conversation not directed at the bird, most need direct and numerous repetitions of the phase to be learned. In most cases this direct training involves someone standing at the cage repeating the same phrase over and over. Training the bird to speak even a single phrase can take hours of repetition over a several week period, if the bird will learn to speak at all. A need exists for a device to train a bird with minimal human effort.
One example for such a device is disclosed in U.S. Pat. No. 3,847,120 to Hicks entitled "Bird Training Device." The Hicks device uses a magnetic tape playback device attached to a mechanical switch. The switch is in the form of a perch in front of a mirror. The bird, being attracted by its image in the mirror, is supposed to alight on the perch and by its weight flip the switch and activate the tape. The tape, in the form of an endless loop, repeats as long as and as often a the birds weight is on the perch.
The Hicks device, therefore, relies upon the bird itself to activate the training mechanism. If the bird never lands on the perch or, even more likely, is frightened by the voice right next to it when it does land on the perch and flies away, the whole purpose of the device is thwarted. Without the bird choosing to land on the perch no training ever takes place. Also, even if the bird can be taught to land on the perch on a regular basis the Hicks device contains no method of changing the message on the magnetic tape. External machinery would be required to provide different messages for the bird.
Another similar device, this time for tending and herding cows, is disclosed in U.S. Pat. No. 3,137,271 to Etter entitled "Means and Method for Tending Domestic Animals." The Etter device uses the same magnetic tape playback means as found in Hicks, but is activated at specific times of the day by a clock mechanism, for example at dawn to tell the cows to come and be milked. The Etter device suffers from the same problem as the Hicks device in that the message can only be changed by external means. Also the Hicks device, though initiated by a clock mechanism, is designed to repeat the message at certain times of the day, it is not designed to repeat the message the specific controllable intervals optimal for training a bird.
A need exists for a device that can be attached to a bird cage and repeat messages to a bird at regular controllable intervals regardless of the birds actions. Such a device must contain a means for changing or recording new messages without the need for external machinery.
SUMMARY OF THE INVENTION
The device for training a bird in a cage which embodies the present invention is self-contained, small and lightweight enough to be attached directly to the bird's cage. The preferred embodiment of the invention includes a microphone for converting the desired message to an analog signal, a solid state analog storage means operationally connected to the microphone for storing the analog signal, a variable timing means connected to the storage means to initiate playback of the analog signal at regular controllable intervals, an amplifier connected to the output of the storage means to provide volume control, and a speaker connected to the amplifier to playback the message to the bird.
A switch is used to set the storage device to record and to initiate recording. Once the switch is closed the user speaks the desired message into the microphone. Recording stops when the storage device is full or the record mode is manually interrupted by opening the switch.
A second switch is used to activate the playback mode and variable timing means. When the switch is dosed the storage means begins playback of the stored analog signal. Once the playback is concluded the timing means is activated and measures the interval before the next playback. The timing means is made variable by a variable resistor connected to the input of the timer, the value of the resistor is determined by the user and controls the amount of time between playback. When the timing means reaches the end of selected interval for playback it activates the storage means and initiates the next playback. When the playback is concluded the timing means are activated again and the process is repeated until the second switch is opened.
The analog signal provided upon playback by the storage means is fed by direct connection to an amplifier used to provide volume control. The amplifier is connected to a variable resistor which controls the gain of the amplifier. The value of the resistor is determined by the user and controls the volume of the playback. The output of amplifier is connected to a speaker which converts the analog signal back into an audio message to be heard by the bird.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of the primary circuit of the device for training a bird in a cage.
FIG. 2 is a schematic representation of the timing circuit used to activate playback after a specified controllable interval.
FIG. 3 is a schematic representation of the amplifier to provide volume control for the output of the speaker.
FIG. 4 is a schematic representation of the on/off switch for the device and the power supply to the circuits of FIGS. 1-3,
FIG. 5 is the front view of the device to train a bird in a cage.
FIG. 6 is the side view of the device.
FIG. 7 is the rear view of the device.
FIG. 8 is a rear view of an alternate embodiment of the device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a representation of circuit 10, the main functional circuit of the device. Circuit 10 is comprised of storage device 12, an integrated circuit chip with means to store an analog signal, and supporting components.
Initiation of playback of the analog signal is controlled by cross-coupled latch 14. The cross-coupled latch is comprised of first NAND gate 16 and second NAND gate 18. Input 22 of first NAND gate 16 is connect to resistor 24 and first switch 20. The other terminal of switch 20 is grounded. The other terminal of resistor 24 is connected to voltage high (±5 V) 8, this pulls input 22 high when firs switch is open. Input 26 of first NAND gate 16 is pulled high by resistor 30, connected at its other terminal to voltage high.
Output 44 of first NAND gate 16 is connected to input 46 of second NAND gate 18 through resistor 45. Resistor 45 serves to ensure that the cross-coupled latch powers up in a reset state and should be of sufficient value to accomplish that task. Input 48 of second NAND gate 18 is connected to the end of message signal ("EOM") pin 42 of storage device 12. Referring briefly to FIG. 2 it can be seen that "EOM" is held high by resistor 170 which is connected to a voltage high 8 of ±5 V until the storage device 12 has finished playback of the analog signal at which time it outputs a low signal. Returning to FIG. 1, output 50 of second NAND gate 18 is connected to input 26 of first NAND gate 16, and to the control pins 37 of storage device 12 through diode 28. Diode 28 isolates output 50 when it is in a high state from the control pins. The control pins consist of "/CE", 36, "P/R", 38, and "PD", 40. "/CE" 36 is active low and starts playback and record operations. The state of "P/R" 38 determines whether playback or record is initiated when /CE is activated. "P/R" places the storage device 12 in playback mode when the pin is at a high voltage and places the storage device 12 in record mode when the pin is at a low voltage. "PD" 40 activates power down mode and resets the memory of storage device 12 when PD 40 is high. Resistor 32 and capacitor 34 provide set up time for /CE when record mode is selected by setting P/R low.
Second switch 52 is connected between ground 6 and the inputs 58 to the third NAND gate 54. The inputs 58 are held high by pull-up resistor 66 connected between inputs 58 and voltage high 8 while switch 52 is open. Polarized capacitor 67 is connected between inputs 58 and ground, and serves to debounce switch 52. The output 60 of third NAND gate 54 is connected to the inputs 62 of fourth NAND gate 56. The output 64 of fourth NAND gate 56 is connected to P/R. The output 64 is also connected through diode 70, used to isolate a high output from fourth NAND gate 56 from analog storage device 12, to resistor 32 and capacitor 34, which serve to provide the set up time for /CE 36 and PD 40.
When first switch 20 is closed, input 22 is grounded and goes low causing the output 44 of first NAND gate 16 and therefore input 46 to be high. With input 48 driven high by a high signal at EOM 42, the output 50 of second NAND gate 18 is driven low thereby activating /CE 36 and PD 40 and initiating playback of the stored analog signal. Diode 70 prevents the low output 50 of the second NAND gate 18 from driving P/R 38 low, which would place storage device 12 into record mode. At the end of the playback, EOM is driven low by the storage device 12, resetting the cross-coupled latch 14, which places PD in a high state and powers o down the storage device 12. The low EOM pulse also provides the input to the timing means 126.
Recording a new message is accomplished by closing the second switch 52 causing a low voltage at the inputs 58. The low inputs 58 of third NAND gate cause the output 60 of the third NAND gate to be high which causes the inputs 62 of the fourth NAND gate 56 to be high. The high state of the inputs 62 cause the output 64 of the fourth NAND gate to be driven low. The low output 64 of the fourth NA gate 56 drives P/R 38 low, thereby placing the storage device 12 in record mode. The output 64 is also connected to PE and PD through diode 70, resistor 32 and capacitor 34. A low signal at 64 drives PE and PD low, initiating recording of the analog signal, after a brief set up time provided by resistor 32 and capacitor 34. Recording stops when the analog signal fills the storage device 12 buffer or when manually stopped by opening second switch 52.
Power is supplied to the storage device by connecting voltage high 8 to VCCD 80. This supplies power to the digital sections of storage device 12. VCCA 82 is also connected to voltage high 8 and supplies power to the analog sections of storage device 12. Both VCCD and VCCA are connected to high frequency decoupling capacitors, 88 and 90, which are then connected to ground 6.
AGC input 92 of storage device 12 provides automatic gain control for the microphone preamp by forming a feedback loop to adjust the gain of the preamp for changes in the analog signal. The attack and release time constants for the AGC input are provided by capacitor 94 and resistor 96. Pin 98 of the storage device 12 is the direct analog output of microphone preamp. It is connected through capacitor 100 to pin 102 which is the input to the amp that drives the storage array of storage device 12. The storage array of storage device 12 samples the analog signal at a predetermined frequency and stores the voltage value in one of a plurality of non-volatile cells. The preferred embodiment uses one of the ISD1000A series, ISD 1100 series, ISD1200 series, ISD1400 series or ISD2500 series of ICs. The selection of the chip corresponds to the length of the analog signal to be stored. The ISD chips provide a maximum storage capability of 10 to 60 seconds depending on the chip selected.
Pin 104 is the input to the microphone preamp of storage device 12. Pin 104 is connected to the microphone 105 thorough coupling capacitor 110. The microphone 105 is then connected to ground 6. The inverting input 106 to the microphone preamp is connected to ground though a capacitor 108 and provides noise canceling to the analog signal. In the preferred embodiment, capacitor 108 is the same value as decoupling capacitor 110.
Pin "SP-" 112 is the output of storage device 12 which provides an analog signal to the input 118 of the amplifier circuit 200 of FIG. 3 through resistor 114 and capacitor 116. Pin "SP+" 120 is an alternate output of storage device 12 and should remain unconnected if not used. "Aux In" 109 is not used and should also remain unconnected. Address pins 122 of storage device 12 are unused and are tied to ground 6. The internal clock of storage device 12 is enabled by connecting the extend clock input 124 to ground 6.
Node 126 is connected to EOM 42 which is used to initiate the variable timing device. Node 128 represents the output of timing means circuit 150 of FIG. 2.
FIG. 2 shows the circuit 150 which represents the preferred embodiment of the timing means. The preferred embodiment uses two timers 152 and 154 that generate a square wave pulse at the end of a predetermined, but variable, interval. The timers 152 and 154 are connected in series to provide the optimal range of specified controllable intervals. The circuit of FIG. 2 shows two NE555 ICs, 152 and 154, which serve as the timers. The first timer 152 is configured with the inputs 156 connected to variable resistor 158 and capacitor 160 which determine the time delay. The capacitor 160 can be changed to extend the interval time. For example, using the variable resistor 158 a capacitor of 100 microfarads would provide a maximum specified controllable interval of five minutes. Using a capacitor 160 with a value of 1000 microfarads extends the maximum specified controllable interval to thirty minutes. The control voltage input 162 of the first timer 152 is connected to ground 6 through capacitor 164 which prevents false triggering. The reset input 166 is connected directly to high voltage 8.
The output 172 of first timer 152 is connected directly to the trigger 174 of second timer 156. Trigger 174 is held high by resistor 176 connected between trigger 174 and high voltage 8. The time delay of second timer 154 is fixed by resistor 180 connected between high voltage 8 and inputs 178, and by capacitor 182 connected between inputs 178 and ground 6. Control voltage 184 is connected to ground 6 through capacitor 186 to prevent false triggering just as before. Reset input 188 is again connected directly to high voltage 8. The output 190 of second timer 154 is connected to node 128 of FIG. 1.
The time delay for the first timer 152 is controllable by the user by varying the value of the variable resistor 158. The first timer 152 is activated by a low pulse at trigger 168 from input 126 supplied by EOM 42 from FIG. 1. The trigger 168 is kept high by pull up resistor 170 until taken low by the signal input from node 126. The output 172 at the end of the timing cycle of first timer 152 activates second timer 154. The output 190 of second timer 154 at the end of the timing cycle activates playback by causing /CE 36 and PD 40 to go low. A low pulse of EOM 42 at the end of the analog signal restarts the timing circuit 150.
FIG. 3 shows circuit 200 which provides the volume control for the analog signal on playback from the storage device 12. Volume control is provided by the variable resistor 204 which controls the gain for the op-amp 202. The input to the amplifier 118 is connected to the positive input 208 of the op-amp 202, through the variable resistor 204. The negative input 206 of the op-amp is connected to ground 6. The power for the op-amp is provided by connecting the VCC 214 of the op-amp to high voltage 8 and the op-amp is grounded by connecting the op-amp ground 212 directly to ground 6. The output 210 of the op-amp is connected to the speaker 218 through a polarized coupling capacitor 216.
Voltage high 8 is provided by circuit 220 shown in FIG. 4. Battery 222 is connected between on/off switch 224 and ground 6. Diode 226 is connected between on/off switch 224 and regulator 228 to isolate the battery 222 when switch 224 is closed. The input 230 of the regulator 228 is connected to ground through the polarized coupling capacitor 236, and the output 232 of regulator 228 is connected to ground through coupling capacitor 238. The ground pin 234 of regulator 228 is connected directory to ground 6. The output 232 of the regulator 228 is voltage high 8 used in FIGS. 1-4.
The following element values were employed in the circuits of FIGS. 1-4 in one successful embodiment of the invention:
______________________________________Drawing No. Element Part No. or Value______________________________________ 12 Voice Record/ Any of the ISD1000A, ISD1100, Playback IC ISD1200, ISD1400 or ISD2500 series of ICs16, 18, 54, 56 NAND gate 4093 Schmitt trigger quad NAND package20, 52 Single Position Single Throw Switch28, 68, 70 Diode 1N914226 Diode 1N4001152, 154 Timer NE555228 T5 7805202 Operational LM386 Amplifier158, 204 Variable 1 meg Resistor 24 Resistor 47K 30 Resistor 47K 32 Resistor 47K 45 Resistor 1K 66 Resistor 100K 96 Resistor 470K114 Resistor 1K170 Resistor 10K180 Resistor 10K176 Resistor 10K 34 Capacitor .1 microF 67 Capacitor 1 microF 88 Capacitor .1 microF 90 Capacitor .1 microF 94 Capacitor 4.7 microF100 Capacitor 1 microF108 Capacitor .22 microF110 Capacitor .22 microF116 Capacitor .22 microF160 Capacitor 100 to 1000 microF164 Capacitor .05 microF182 Capacitor 10 microF186 Capacitor .05 microF216 Capacitor .22 microF236 Capacitor 220 microF238 Capacitor .01 microF______________________________________
FIG. 5 is the frontal view of the device and consists of a container 250. The front face of the container 250 contains two buttons 252 and 254. The play button 252 is operationally connected to first switch 20 in FIG. 1. The record button 254 is operationally connected to second switch 52 in FIG. 1. The front face 251 also contains an on/off switch 256 operationally connected to on/off switch 224 in FIG. 5 and an opening 258 to expose the microphone 105 in FIG. 1 to receive the analog signal.
FIG. 6 is the side view of container 250. The volume dial 260 is operationally connected to the variable resistor 204 in FIG 3 and allows the user to select the volume level. The interval dial 262 is operationally connected to the variable resistor 158 in FIG. 2 and allows the user to select the specific controllable interval at which the analog signal is played back.
FIG. 7 is the rear view of container 250 and contains the speaker grill 264 through which the speaker 218 from FIG. 3 plays. FIG. 7 also shows the battery receptacle 266 which houses the battery 222 from FIG. 4. Finally the rear view shows the clip means 270 by which the container 250 is attached to the cage. Slot 268 allows the clip means 270 to be adjusted for specific cages.
FIG. 8 is a rear view of an alternate embodiment of container 250. Container 250a includes speaker grill 264a and shows battery receptacle 266a. Instead of clip means 270 and slot 268 shown in FIG. 7, container 250a uses loop and hook fabric 270a held to container 250a by bar 268a.
It should be understood that various modifications can be made to the embodiments disclosed without departing from ,he spirit and scope of the present invention. Various engineering changes and choices can also be made without departing substantially from the spirit of the disclosure. | A device that automatically repeats a prerecorded message for training a bird to mimic the message. The device is sized such that it may be attached to a bird cage by adjustable clips. The device electronically records and stores a message spoken by the user and plays back the message through a speaker for the bird at intervals determined by a timer. A user may record any type of message that the user wishes for the bird to learn. The message may be of variable length up to 60 seconds in duration. The user may select a delay interval between one second and thirty minutes by utilization of the timer. Once the user activates the play-back, the device will play the prerecorded message at a selected volume, automatically repeating in intervals equal to that selected by the user. Thereafter, the device will continue to repeat the prerecorded message at the selected interval until the user deactivates the device. | 8 |
TECHNICAL FIELD OF THE INVENTION
The present invention concerns an apparatus intended to interrogate a distributed optical fibre sensor by means of frequency-domain analysis of the output signal of an optical interferometer that is excited by a first type of wavelength-swept laser source and that comprises the fibre sensor in its measure arm, in a configuration that allows the sensor to be also excited by a second type of laser source that is characterized by a wavelength-shift with respect to the first laser source that produces light amplification (or depletion) by stimulated Brillouin scattering within the sensing fibre.
The “Brillouin effect” is a non-linear scattering phenomenon in which incident photons of light interact with mechanical vibrations of the medium inside which they propagates to get scattered with a wavelength shifted with respect to the original one, in which the wavelength shift is related to the electro-optical characteristics of the same medium and to the physical characteristics, among which mechanical strain and temperature, that can later such characteristics.
Due to the small entity of the Brillouin wavelength shift in conventional optical fibres, measuring such parameter requires techniques sophisticated and expensive to be implemented.
PRIOR ART
1) BOTDR/BOTDA
Are known several Brillouin sensor interrogators based on time-domain analysis of the propagation of light pulses in an optical fibre. The documents JP2001356070 (also disclosed as GB2368638B), GB2243210A, WO9827406A1, WO2007043432A1 JP2011232138A, JP2007240351A, JP2012063146A, EP0887624A2, WO2006001071A1, JP2009080048, JP2009198389, JP2010217029, U.S. Pat. No. 7,283,216 B1 and EP1760424A1 disclose Brillouin Optical Time-Domain Reflectometers (BOTDR) that combine the time domain reflectometry principle with techniques capable to determine the wavelength shift of the back-scattered photons in a sensing optical fibre due to spontaneous Brillouin scattering effects.
The documents WO2012156978A1, WO2012084040A1, WO2007086357A1, JP2007033183, JP10048065, FR2710150, JP4077641, JP4077641, EP0348235A2, EP1865289A2, EP0348235, DE102008019150A1, JP6273270, JP2010008400A, JP2008286697A, JP2007178346A, US2008068586A1, US2008018903A1, WO2006001071A1 and WO2014155400 disclose Brillouin Optical Time-Domain Analysers (BOTDA) that combine the time domain analysis with stimulated Brillouin scattering between two types of “pump” and “probe” light characterized by a controllable wavelength-shift, in particular the document WO2014155400 discloses the use of a tuneable Brillouin ring laser to produce the wavelength-shifted light. Brillouin interrogators based on time domain analysis are characterized by:
a distance resolution intrinsically limited at ˜10 cm due to the minimum life-time of the Brillouin phonon in the non-stationary (pulsed) propagation scheme; no capability of separating the strain and temperature effects due to their intrinsic combination in contributing to the entity of the Brillouin wavelength shift; the use of high-speed light intensity modulator(s) (expensive parts) to produce the pulsed propagation that is necessary for the time-domain interrogation; the use of high-power optical amplifier (expensive part) for the pump light for having an appreciable Brillouin amplification even with the very small interaction time consequent to the pulsed propagation that is necessary for the time-domain interrogation; the use of one high-speed sampling digitizer (expensive part) for recording the time-varying perturbation on the probe lightwave that allows to reconstruct the distance distribution of the Brillouin amplification (minimum 2·10 9 samples/s for a 10 cm resolution).
2) BOCDA
The document K. Hotate and T. Hasegawa, IEICE Trans. Electron., E83-C, 3 (2000) discloses a Brillouin sensor interrogator based on Optical Correlation-Domain Analysis (BOCDA) according to the schematic in the frame 2 of the FIG. 1 , where frequency-modulation is applied to both probe and pump light by means of Alternate Current (AC) superimposition to the bias current of a Distributed Feed-Back laser Diode (DFB-LD). Such modulation controls the position along the sensing fibre at which the Brillouin amplification can occur due to the matching of the optical correlation between the two modulated pump and probe lightwaves. In the BOCDA the light propagation and Brillouin scattering in the sensor are stationary in time and space, that allows to overcome the large distance resolution limit of non-stationary time-domain interrogation schemes (BOCDA resolution down to 1.6 mm have been reported). BOCDA is necessarily characterized by:
limitation of the sensor length (maximum range of 1 km has been reported) due to the practical feasibility limits of the frequency modulation of the laser source; no capability of separating the strain and temperature effects due to their intrinsic combination in contributing to the entity of the Brillouin wavelength shift; the use of multiple light intensity modulators (expensive components) to produce the wavelength-shift required for stimulated Brillouin amplification and for controlling the position of the correlation peak; the use of expensive power optical amplifier (expensive component) for the pump light.
Known BOCDA embodiments are also characterized by:
a non-swept DFB-LD laser source that can be frequency modulated within few MHz around the centre frequency but that is not suitable for being swept over a much broader (i.e. 20 nm) wavelength interval; not comprising any interferometer neither in the sensor path nor in the general layout; and p 1 the generation of the wavelength-shifted Brillouin probe by means of optical side-band modulation technique involving the use of expensive parts such as high-speed nested electro-optical modulator and microwave synthesizer and amplifiers.
3) Rayleigh-OFDR
Several documents (i.e.: M. K. Bamoski and S. M. Jensen—“Fiber waveguides: A Novel Technique for Investigating of Attenuation Characteristics”, Appl. Opt., vol. 16, pp. 2112-2115, 1978) disclose Frequency (or Wavelength) Scanning Optical Frequency-Domain Reflectometers (FS-OFDR or WS-OFDR) that can be ascribed to the schematic in the frame 1 of the FIG. 1 . The OFDR comprises an optical interferometer in which the sensing fibre is part of the measurement arm, and that is excited by a wavelength-swept coherent light source. Each single propagation discontinuity in the measurement arm (i.e. Rayleigh and Fresnel reflections sources for a backreflection sensing scheme like the one illustrated) produces an individual output signal contribution by interfering with the signal of the reference arm, the intensity of which arises form the interference condition that is on the wavelength of the excitation source and on the relative position of the specific discontinuity that generates the signal on the measurement arm with respect to the length of the reference arm. By linearly sweeping the wavelength of the excitation source the intensity of each single output signal contribution results sine-modulated with a frequency that depends on the location of the discontinuity source, thus, by Fourier transforming the signal into the frequency domain each single discontinuity (and its intensity) can be individually identified with a single frequency spectral line of the signal (and its intensity).
OFDR distance resolution Δz depends on the width of the wavelength sweeping interval that is swept by the excitation source according to the relation Δz≈cλ 2 /(2n g Δλ) in which c is the speed of the light, n g is the group refractive index, λ is the average wavelength of the excitation light and Δλ is the wavelength sweeping width (40 nm sweeping width achieves 20 μm resolution), furthermore the information content of the output signal is produced by optical interference phenomena, a condition that allows the use of coherent detection techniques having sensitivity and signal/noise performance much better than those achievable in time-domain, correlation-domain and modulation-transfer techniques. It is also known the use of OFDR for distributed strain and temperature sensing by means of the evaluation of Rayleigh wavelength shift.
OFDR is necessarily characterized by:
no capability of separating the strain and temperature effects due to their intrinsic combination in contributing to the entity of the Rayleigh wavelength shift (similarly to what happens for Brillouin shift); intrinsic limitations of the Rayleigh-shift technique in the measurement of large strain (temperature) changes due to the difficulties in recognizing large changes in the pattern of Rayleigh reflection sources;
Known OFDR embodiments are also characterized by:
using Rayleigh scattering sources (and not being capable to selectively detect and recognize Brillouin scattering sources); not inducing stimulated Brillouin scattering neither in the sensor path nor in the general layout for the use in the OFDR.
4) Modulation-transfer BOFDA (Improper BOFDA)
The documents Garus D. et al. “Brillouin Optical-Fiber Frequency-Domain Analysis for Distributed Temperature and Strain Measurements”, J. of Lightwave Techn., Vol. 15, No. 4 (April 1997) [D1], DE19950880 [D2], EP2110646A2 [D3] and Kasinatan M. et al. “Analysis of Stimulated Brillouin Scattering Characteristics in Frequency Domain”, Int. Conf. on Optics and Photonics (ICOP 2009, Chandigarh, India, Nov. 1, 2009) [D4], all disclose variants of a same device that is improperly-named Brillouin sensor interrogator based on Optical Frequency-Domain Analysis (BOFDA). The working scheme of this device is sketched in the frame 3 of the FIG. 1 , and is characterized by the fact that the Brillouin pump is intensity-modulated by a modulation signal containing various frequency components (from 10 kHz to 20 MHz reported) by means of an electro-optical intensity modulator and is then injected in the sensing fibre in counter-propagation with a Continuous Wave (CW) non-modulated Brillouin probe. At the sensor locations where the strain- and temperature-dependant Brillouin wavelength shift matches the actual wavelength shift between the pump and the probe, Brillouin amplification occurs and transfers the intensity modulation from the pump to the probe, but with a phase delay with respect to the injected pump modulation that depends on the modulation frequency and on the position along the sensor where the modulation transfer happens. The probe signal containing the transferred modulation is then analysed in the frequency-domain after Fast Fourier Transforming (FFT) and the phase and amplitude transfer function with respect to the modulating signal is exploited in order to reconstruct the position dependence of the Brillouin-induced modulation-transfer along the sensor fibre. In such sensor interrogation scheme the light propagation is stationary in time and space, that allows to overcome the distance resolution limit of time-domain interrogation schemes. However, in the modulation-transfer BOFDA the information content of the perturbed probe is derived from a local transfer process of the pump modulation and not from local optical interference phenomena like it happens in the real Optical Frequency-Domain Reflectometers (OFDR, that will be described in the following) and for this reason the system has to be considered and improper BOFDA.
The document [D1] discloses a first variant of the modulation-transfer BOFDA where is used a conventional Optical Phase-Locked Loop (O-PLL) technique between two separate Nd:YAG tuneable lasers in order to produce the pump and probe with the desired wavelength-shift. It has to be noted that the “tuneability” of the lasers (pag. 655, left column, first row) is only used to achieve a controlled wavelength shift between the two lasers (pag. 655, left column, rows 5-7) by means of a feedback loop fed by their heterodyne signal (pag. 660, FIG. 9). The disclosed solution uses Nd:YAG lasers that are not suitable for producing a wavelength swept signal due to the slow and non-linear tuning mechanism and that are characterized by a tuneability limited to only 0.4 nm (=120 GHz, Koechner W., Solid-State Ingegneria Laser, 2 nd Ed., Springer-Verlag, 1998). The use of the tuneable source for providing a wavelength-swept excitation is neither disclosed nor suggested in the documents as well as any idea by itself of wavelength-sweeping any of the laser sources, for this reason nothing in the prior art discloses, hits or makes obvious the use of a wavelength-swept laser excitation source.
The document [D4] discloses a second variant of the modulation-transfer BOFDA where a conventional optical side-band modulation technique is used to generate the wavelength-shifted probe signal from a fraction of the output of the same fixed-wavelength DFB laser that sources the pump signal, using a second expensive optical modulator. This provides a further clue that the tuneability of the Nd:YAG source cited in the other paper represents only an incidental condition and is out of the scope of the modulation-transfer BOFDA sensing mechanism and that nothing in the prior art discloses, hits or makes obvious the use of a wavelength-swept laser excitation source.
Furthermore no prior art discloses, suggests, makes obvious or even simply imaginable the use of an optical interferometer (in particular Michelson-type or Mach-Zehnder type, with classical or modified topology) for the scope of resolving the distance distribution of stimulated Brillouin amplification in the sensor, and in particular for generating an interference signal between two fractions of the same excitation lightwave only one of which is amplified (or attenuated) at some sensor locations by stimulated Brillouin interaction. The only interferometer cited ([D1], pag. 655, left column, line 9) is a Fabry-Perot tunable filter in a setup for Brillouin linewidth measurement (pag. 655, FIG. 1) that is out of the scope of the Brillouin distributed sensing and that is not configured to have Brillouin amplification in any of its light interference paths.
Similarly, no prior art discloses, suggests, makes obvious or even simply imaginable the use of a coherent detection technique for selectively detect the unbalancing of an optical interferometer by means of a balanced differential photodetector, where the said unbalancing arises by the occurrence of Brillouin amplification in the measurement arm that comprises the sensing fibre of an interferometer.
The known modulation-transfer BOFDA require one [D1] or even two [D4] optical intensity modulators (expensive parts).
Due to practical feasibility reasons, however, the improper-BOFDA is necessarily characterized by:
limitation of the distance resolution (maximum resolution of 5 cm has been reported) due to the difficulties of compensating for the non-linear behaviour of the optical modulator; no capability of separating the strain and temperature effects due to their intrinsic combination in contributing to the entity of the Brillouin wavelength shift; the use of at least one light intensity modulator (expensive component) to introduce the pump modulation; the use of one medium-speed sampling digitizer (relatively expensive part) for digitizing the modulated lightwave at least twice of its highest frequency content (Nyquist frequency limit).
Known improper-BOFDA embodiments are also characterized by:
the use of non-swept laser sources for both the pump and probe signal; not comprising any interferometer neither in the sensor path nor in the general layout; and neither using nor being capable to take advantage from coherent optical detection and not being suitable for using balanced differential photodetectors to be connected at the differential output ports of a Mach-Zehnder or Michelson interferometer, either in a traditional or modified topology.
5) Wavelength-division Multiplexed OFDR+BOTDA Hybrid
The document Zhou D. et al., “Distributed Temperature and Strain Discrimination with Stimulated Brillouin Scattering and Rayleigh Backscatter in an Optical Fiber”, Sensors 2013, 13, 1836-1845 discloses an hybrid OFDR+BOTDA solution according to the schematic in the frame 4 of the FIG. 1 , in which the same sensing fibre can be interrogated by a known OFDR apparatus operating in the “C band” (1531+1570 nm) and by a known BOTDA apparatus operating at 1310 nm by means of a conventional Wavelength-Division Multiplexing (WDM) technique. The said hybrid solution has the scope of decoupling the effect of the strain and of the temperature by means of solving the system of equation that is obtained by measuring the distribution of Rayleigh wavelength shift and the distribution of Brillouin frequency shift. Such known hybrid OFDR+BOTDA embodiment is characterized by:
using separate OFDR and BOTDA that share the same sensing fibre by means of WDM, thus multiplying the cost of the equipment; using a time-domain technique for the Brillouin sensor interrogation that retains all its typical limitations.
SCOPE OF THE INVENTION
The main scope of the present invention is that of achieving an apparatus for interrogating optical fibre sensors based on the stimulated Brillouin scattering that could overcome the distance resolution performance limitation and that could break down the level of cost of the known devices.
Secondary (I) scope of the present invention is that of achieving an apparatus capable of Brillouin distributed sensor interrogation in which, in order to reconstruct the distance distribution of the Brillouin amplification effect, it is employed a properly said optical interferometer suitable for outputting a signal suitable for coherent optical detection and balanced differential photodetector demodulation.
A further (II) secondary scope of the present invention is that of achieving an apparatus capable of Brillouin distributed sensor interrogation using a CW (non-pulsed) propagation scheme in which it is not use any optical modulator component.
A further secondary (III) scope of the present invention is that of achieving an apparatus capable of both Brillouin-shift and Rayleigh-shift distributed sensor interrogation by means of switching the configuration of the same set of components.
A further (IV) secondary scope of the present invention is that of achieving an apparatus capable of Wavelength-Scanning Brillouin Optical Frequency-Domain distributed sensor interrogation using a technical solution to generate the Brillouin pump and probe lightwaves capable to overcome the limitations of other known solutions (O-PLL and O-SSB) in terms of industrial cost, critical tuning, technical complexity, stability and reliability.
A further secondary scope (V) of the present invention is that of achieving a wavelength-agile apparatus capable of Brillouin distributed sensor interrogation that is capable to maintain the required wavelength shift between Brillouin pump and probe signal without the need of complex and sophisticated adjustments of the operating parameters with the changes of the wavelength.
DISCLOSURE OF THE INVENTION
In a first broad independent aspect the present invention provides a Wavelength-Scanning Brillouin Optical Frequency Domain Analyser (WS-BOFDA) apparatus comprising:
a1) a wavelength-swept primary source of coherent light; and a2) a secondary wavelength-shifted source of coherent light, having instant-by-instant a wavelength shift controllable and known with respect to the wavelength of the primary source during the wavelength-sweeping process; and a3) an optical interferometer in which the excitation light, supplied by a first one of the above mentioned sources, is split into the measurement arm, comprising the sensing fibre, and into the reference arm; and it is then recombined to produce an optical interference signal; and a4) means to route the light supplied by the second one of the mentioned sources into the measurement arm of the said interferometer in order to produce local Brillouin amplification (or attenuation) at any sensor location at which the current wavelength shift falls within the local temperature and strain dependent Brillouin gain band; a5) means to measure the interference signal at the differential outputs of the interferometer with a balanced differential photodetector; and a6) means to detect and analyse the measured interference signal in the frequency domain with respect to the value of the wavelength-swept interferometer excitation and at different values of the wavelength shift between the two sources.
Due to the interference between the fraction of excitation signal that arrives unperturbed from the reference arm of the interferometer and the fraction that arrives amplified by local Brillouin effects in the measurement arm, any Brillouin amplification source along the sensor will contribute to the total output signal intensity depending on its location (path length) and on the excitation wavelength, so that, when the excitation wavelength is swept, each single intensity contribution will periodically vary with a frequency that depends on the source location along the sensor, and by analysing the total output signal in the frequency domain, i.e. by Fast Fourier Transforming (FFT), each amplification source is easily identified and resolved as a specific frequency component. By varying also the wavelength shift between the two sources, sensor locations performing as Brillouin amplification sources at different conditions of temperature and strain are then detected and recognized.
The technical effects of the introduced innovations are:
b1) the combination of the points a1), a3) and a6) provides the capability of resolving the distance distribution of the amplification (or attenuation) sources by means of wavelength-scanning optical frequency-domain interferometry and without the use of any expensive optical modulator component; and b2) the combination of the points a2), a4) and a6) provides the capability of inducing local Brillouin amplification (or attenuation) sources in the sensing fibre according to a CW propagation scheme requiring reduced Brillouin pump power (thus avoiding the need of expensive optical power amplifiers) and it also provides the capability of locating the Brillouin peak frequency shift in the sensor by interpolating the gain measurements at different wavelength shifts between the two sources; and b3) the combination of the points a5) and a3) provides the capability of selectively detect and distinguish the unbalancing of the interference signal that is due to the presence of amplification (or attenuation) sources in the sensing fibre allowing thus to distinguish the wanted information from other noise sources that are necessarily present due to the sensor interrogation scheme (in particular that from the light injected in the measurement arm only that produces a common mode signal at the outputs of the interferometer, directly or indirectly by Rayleigh backscattering according to the propagation scheme);
This unique combination of features provides a solution for the main scope and for the secondary scopes (I) and (II) that is not only novel but also characterized by a combination of substantial innovations (points from a1) to a5)) that, are not suggested, hinted, made obvious or simply imaginable for a technician with experience in the field of Brillouin sensing considering the known prior art.
In a first subsidiary aspect the present invention provides a solution capable of both Brillouin-shift and Rayleigh-shift distributed sensor interrogation according to the secondary scope (III) by means of an optic switch (or variable attenuator) configured to control the routing of the excitation of the interferometer and of the Brillouin interacting lightwaves, so that the same Wavelength-Scanning Optical Frequency-Domain Analyser can be switched between a “Brillouin mode” in which both Brillouin pump and probe lightwaves are injected in the sensor in order to generate local Brillouin interactions, and a “Rayleigh-mode” in which both arms of the interferometer are excited only by fractions of the same lightwave in a configuration capable to measure the distribution of local Rayleigh scattering sources. The technical effect of this further innovation is the capability of performing both Brillouin and Rayleigh-shift distributed measurements and separate the contributions of temperature and strain in the same sensor, with a solution that, by allowing to use the same hardware for both scopes, is more cost effective and space-saving.
In a second subsidiary aspect the present invention provides a Wavelength-Scanning Brillouin Optical Frequency-Domain distributed using a Brillouin ring laser in order to generate a wavelength-shifted signal suitable to perform as Brillouin probe, with a wavelength shift that is intrinsically locked to the pump light source in particular remaining constant and locked instant-by-instant during the wavelength-sweeping process of the primary source, and where the said wavelength-shift is also easily tuneable in order to allow the Brillouin frequency analysis required by the distributed sensing scope. The technical effect of this further innovation is the capability of overcoming the limitations of other known solutions (O-PLL and O-SSB) in terms of industrial cost, critical tuning, technical complexity, stability and reliability according to the secondary scope (IV) and to provide a solution for sourcing the wavelength-shifted pump and probe signal that is compatible with a wavelength-swept interferometer excitation process such as required for the WS-BOFDR scope, in particular according to the secondary scope (V).
In further subsidiary aspects, the present invention may also comprise:
reflector or absorber mean(s), possibly having partial reflection/absorbance characteristics fixed or variable, suitable for inducing a stationary lightwave propagation in the sensing arm of the interferometer; system(s) for suppressing the mode-hopping in the Brillouin ring laser such as a mode mixer, active or passive, or a system capable to change the resonance length of the cavity of the Brillouin ring laser so that to tune it continuously during the wavelength-seeping of the primary laser source; system(s) for purging the spectrum of the Brillouin ring laser, such as means to interrupt the laser ring feedback or to change the optical gain of the cavity or change its optical attenuation so that to suppress the drift and hysteresis of the Brillouin ring laser that are related to the wavelength sweeping process; mean(s) to control and stabilize the strain and/or temperature of the Brillouin gain medium of the Brillouin ring laser, i.e. by means of a feedback control system comprising also sensors of strain and/or temperature; mean(s) to control the polarization such as for example a polarizer or a polarization controller in any of the arms of the interferometer or in any of the light injection arms; polarization-sensitive photodetector mean(s) in the detector and analyser system; mean(s) to generate optical pulses in order to limit the time of interaction of the Brillouin pump and probe in the measurement arm i.e. with the scope of extending the measurement range by limiting the area of pump depletion; light waveguide(s) having enhanced Brillouin gain such as a Photonic Crystal Fibre (PCF), a silicon photonics waveguide, an optical fibre having reduced mode field diameter, a Telluride and/or chalcogenide and/or Bismuth-glass optical fibre, a non-linear optical fibre having an optimized overlapping between the longitudinal modes optical and acoustical, also possibly connected with multiple different waveguide sections; mean(s) of optical amplification such as Erbium-doped fibre amplifier, Semiconductor Optical Amplifier, Raman amplifier, Brillouin amplifier; mean(s) of variable optical attenuation; mean(s) to change the length of the reference arm of the interferometer such as an external changeable patch cable or optical switch, so that to allow an usable sensing length exceeding the coherence length of the laser sources that excites the interferometer; auxiliary interferometer(s), having a constant arm length unbalancing and suitable for measuring the wavelength-sweeping speed of the primary source in order to linearize the data acquisition during the sweeping process; wavelength reference(s) such as HCN atomic absorption cell, and/or interference ethalon comb generator and/or Bragg reflector for calibrating the wavelength sweeping process.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 illustrates the relevant prior art.
FIG. 2 illustrates a first preferred embodiment of the present invention according to the transmission-type configuration.
FIG. 3 illustrates a second preferred embodiment of the present invention according to the transmission-type configuration.
FIG. 4 illustrates a third preferred embodiment of the present invention.
FIG. 5 illustrates a fourth preferred embodiment of the present invention.
FIG. 6 illustrates a fifth preferred embodiment of the present invention in which the interferometer is arranged according to Michelson configuration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specifications, which makes reference to the appended figures, in which:
The FIG. 2 discloses a partial schematic representation, non-limiting, of an embodiment of an apparatus according to the present invention in which the sensing fibre ( 34 ) is connected in a transmission-type configuration.
The apparatus comprises a primary laser ( 12 ) that sources a monochromatic light of wavelength λ P , sweepable and having a spectrum as illustrated in the frame ( 24 ), with linewidth smaller that the Brillouin gain bandwidth in the sensing fibre (that is suitable to perform as stimulated Brillouin pump or probe).
The said light seeds a Brillouin ring laser optical circuit ( 14 ) by means of a circulator ( 15 ) and, after having been amplified by an optical gain block ( 16 ), preferentially bi-directional, is injected in a Brillouin gain medium waveguide that is kept in uniform and controllable conditions of strain and temperature T b . In the gain medium the seed light generates backward and forward Brillouin scattering. The depleted seed light, the spectrum of which ( 26 ) also comprises the weak forward Stokes and anti-Stokes Brillouin scattering components, is picked-up by the circulator ( 18 ) after the gain medium ( 17 ) and routed in the fibre ( 23 ) to be injected at the first end ( 32 ) of the sensing fibre ( 34 ) that is connected to the apparatus through the connector ( 30 ).
The Brillouin stokes backscattering in the gain medium ( 17 ) is also amplified by the gain block ( 16 ) and is routed by the circulator ( 15 ) into the closing arm ( 14 ) of the ring circuit to inject it in counter-propagation with the seed that acts as the Brillouin pump. The closing arm ( 14 ) also comprises a piezoelectric fibre stretcher consisting of a length of fibre coiled on a piezo-electric element ( 21 ) having the function of stretching/shortening the length according to the voltage applied to the same element. The closing arm ( 14 ) could also comprise an optical isolator ( 20 ) to impose a single allowed direction for the light propagation in the same closing arm ( 14 ) that is in accordance with the Brillouin back-propagation direction in the gain medium ( 17 ). The said isolator ( 20 ) is in general preferred when the circulator(s) ( 15 ) and/or ( 20 ) are replaced by a different type of routing mean(s) such as for example directional coupler(s).
The ring circuit ( 14 ) constitutes a Brillouin ring laser with an output spectrum ( 25 ) where dominates the backward Brillouin stokes line having wavelength λ P +Δλ(T b ) (that is wavelength-shifted with respect to the seed of a quantity Δλ that is controlled by the temperature of the gain medium. The Brillouin ring laser spectrum is suitable for acting as Brillouin probe light in cooperation with the (depleted) seed used as Brillouin pump.
Part of the backward Brillouin stokes light is picked-up by the coupler ( 19 ) and routed into the arm ( 22 ) in order to perform as the excitation light for the sensing interferometer ( 27 ) that could however have a configuration different from the Mach-Zehnder configuration that is illustrated. The excitation light injected in the sensing interferometer ( 27 ) is divided by a splitter ( 35 ) that injects part of it into the measurement arm that comprises the sensing fibre ( 34 ) and the remaining part into the reference arm constituted by the fiber optic ( 38 ), possibly interchangeable by acting on the optical connectors ( 36 , 37 ). In particular, in the scheme depicted, the excitation light is injected at the sensor end ( 33 ) that is connected to the apparatus though the optical connector ( 31 ) in counter-propagation with the depleted seed light that is injected at the opposite sensor end ( 32 ).
The light perturbed by Brillouin amplification in the sensing fibre ( 34 ) is picked-up by the circulator ( 29 ) and routed to the combiner ( 39 ) where it interferes with the light coming from the reference arm ( 38 ). The differential interference outputs produced by the splitter ( 39 ) are then analyzed by a photodetector taking advantage of their differential characteristic though a balanced differential pair of detectors ( 40 , 41 ), possibly sensitive to the polarization of the light, in order to be digitized and then analysed by the control unit ( 53 ).
Possibly, a small part of the ring laser output can be picked-up from the fibre ( 22 ) though a coupler ( 47 ) for surveying the output power of the ring laser through the detector ( 52 ) and digitizer ( 48 ) and feedback consequently the piezoelectric stretcher ( 21 ) through a control system ( 53 ) and a power amplifier ( 54 ) with the scope of tuning the length of the resonant cavity of the ring laser ( 14 ) following the wavelength sweeping of the primary seed laser ( 12 ), so that to suppress the mode-hopping that could be present in the ring laser with the continuously changing output wavelength. Such mode-hopping suppression can be also achieved by means different from the one that is illustrated such as for example by introducing a mode mixer in the ring circuit ( 14 ) that could be for example constituted by a section of multi-mode fibre connected in the single-mode circuit possibly with tapered splices, or a free-space propagation section between two collimators introduced in the same ring ( 14 ).
Possibly, a fraction of the excitation light of the interferometer can be also picked up i.e. through the coupler ( 42 ) to excite an auxiliary interferometer ( 43 ) used to linearise the wavelength sweep. This said auxiliary interferometer, that can be also arranged in a configuration different from the one (Mach-Zehnder) illustrated, is characterized by measurement and reference arms of fixed length so that to produce an interference output that is function of the wavelength sweep of excitation. The said output is routed to the photodetector ( 46 ), digitized ( 49 ) and used by the control unit ( 53 ) to linearise the wavelength-sweep that the same control unit ( 53 ) imposes to the primary source ( 12 ).
the control system ( 53 ) can also drive a purge system for the output spectrum of the Brillouin ring laser ( 14 ) for example by means of an inhibition pulse ( 55 ) for the optical gain block ( 16 ) in the laser ring or acting on means to introduce optical attenuation or interruption of the ring, or also by means of a transitory inhibition of the seed light.
The reference arm ( 38 ) of the sensing interferometer might also comprise a variety of fibre segments and optical switch(es) or multiplexer(s) capable to change the length of the same arm.
The control system ( 53 ) is configured to perform the following sequence of operations:
a. select a first value of the wavelength shift between the seed and ring laser outputs; b. start a wavelength sweep of the seed source; c. if required, adjust instant-by-instant the cavity length of the ring laser; d. record the output of the sensing interferometer; e. any new fringe detected from the auxiliary interferometer repeat the operations c) to d); f. repeat the operations from c) to e) until the width of the wavelength sweep reaches a value that allows to achieve the desired distance resolution (typically 40 nm sweep for 20 μm resolution); g. analyse the recorded output of the sensing interferometer in the frequency domain with respect to the wavelength sweep in order to reconstruct the distribution of Brillouin amplification sources along the sensor h. select a different value of the wavelength shift between the seed and ring laser output; i. repeat the operations from b) to h) until the desired measurement interval is covered; j. perform an Lorenz interpolation of the Brillouin gain spectrum for each measurement distance point and identify the Brillouin peak gain frequency; k. evaluate and make available the distribution of the Brillouin peak gain frequency with respect to the position along the sensor.
The FIG. 3 discloses a schematic representation, non-limiting, of different embodiment of the apparatus according to the present invention characterized by a “transmission-type” connection of the sensing fibre analogous to the one illustrated in FIG. 2 . The scheme of FIG. 3 is characterized by a different and more simple configuration of the Brillouin ring laser ( 14 ) that does not comprise means to pick-up the depleted seed light. In the scheme of FIG. 3 the counter-propagation of Brillouin pump and probe signals in the sensor ( 34 ) is obtained by injecting at one end ( 33 ) the output of the Brillouin ring laser and at the opposite end ( 32 ) part of the light sourced by the seed laser ( 12 ) and picked-up by a coupler ( 12 ) before the Brillouin ring laser.
The FIG. 4 discloses a schematic representation, non-limiting, of an enhanced embodiment of the apparatus according to the present invention characterized by the additional presence of the optical switch ( 57 ) capable to disable the injection of the light at the end ( 32 ) of the sensor, and are also present additional balanced detector means ( 74 ) to measure the differential interference signal with a balanced differential photodetector between the fraction of the excitation signal reflected along the measurement arm ( 34 ) and the fraction transmitted through the reference arm ( 38 ); while the other first balanced detector means ( 73 ) measures the differential interference signal between the fraction of the excitation signal perturbed by the local Brillouin amplification and transmitted along the measurement arm ( 34 ) and the fraction transmitted through the reference arm ( 38 ).
The apparatus according to FIG. 4 works as a WS-BOFDA when the optical switch ( 57 ) is closed, similarly to what is disclosed in the FIGS. 2 and 3 . When the switch ( 57 ) is opened, for example controlled by the control unit ( 53 ), the apparatus works as an OFDR by analysing the information collected by the detector group ( 74 ) in the frequency-domain with respect to the wavelength sweep and keeping constant the wavelength shift of the Brillouin ring laser. Thank to such mode switching capability the apparatus of FIG. 4 can measure both the distribution of the Brillouin peak frequency along the sensing fibre (WS-BOFDA mode) and the distribution of the Rayleigh wavelength shift along the sensing fibre (OFDR mode) and, considering that the dependence of the Brillouin and Rayleigh shifts from temperature and strain are different and known constants, the distributed measurement of temperature and strain separately obtained. The apparatus of FIG. 4 can also be obtained according to the variants disclosed in the FIGS. 2 and 3 .
The FIG. 5 discloses a schematic representation, non-limiting, of an further embodiment of the apparatus according to the present invention also having the switchable WS-BOFDA/OFDR analysis mode capability and that is characterized by the fact that both the pump and the probe signal are injected from the same end ( 33 ) of the sensing fibre ( 34 ) that constitutes the measurement arm of the interferometer ( 27 ) that is illustrated in an hybrid configuration in which the balanced detector group ( 74 ) receives the interference signal between the back-scattered light in the measurement arm ( 34 ) and the transmitted light along the reference arm ( 38 ).
At the opposite end ( 32 ) of the sensor ( 34 ) it could be present an optical reflector or absorber ( 71 ), possibly partial, to create a stationary or non-stationary lightwave propagation in the sensor. The apparatus of FIG. 5 can also be obtained according to the variants disclosed in the FIGS. 2 and 3 .
The FIG. 6 discloses a schematic representation, non-limiting, of an further embodiment of the apparatus according to the present invention characterized by a Michelson-type configuration of the sensing interferometer ( 27 ) in which the detector ( 74 ) receives the interference signal between the light back reflected by the Brillouin (or Rayleigh) sources along the measurement arm ( 34 ) and the light backreflected by a mirror ( 72 ) at the end of the reference arm ( 38 ). In such configuration the coupler ( 35 ) acts both as splitter and re-combiner. An optical switch ( 81 ) can be also present to switch between a mode in which the sensor is connected in a transmission configuration and a mode in which the sensor is connected in a reflection configuration. This last said switching capability can be also introduced in the other variants of the apparatus according to the present invention.
It is also made clear that in any variant of the apparatus according to the present invention it could be possible to choose the excitation source of the sensing interferometer between the seed laser and the Brillouin ring laser so that to obtain measurement configurations where the unbalancing of the interferometer is due by Brillouin amplification of a Stokes probe signal, or by Brillouin attenuation of an anti-Stokes probe signal, or by depletion or enrichment of the pump signal.
It is also made clear that modifications and variations can be made to the described device without leaving the scope of protection of the present invention. | Apparatus for measuring the distribution of strain and temperature along an optical fibre ( 34 ) by analysing the distribution of the Rayleigh scattering and stimulated Brillouin scattering wavelength shifts along the length of a sensing fibre ( 34 ) using a Wavelength-Scanning Optical Frequency-Domain Analysis (WS-BOFDA) technique in which a wavelength-swept laser ( 12 ) sources a Brillouin “pump” radiation and excites a Brillouin ring laser ( 14 ) that sources a Brillouin “stimulus” radiation with wavelength shifted with respect to the excitation of a tuneable quantity. One optical Mach Zehnder or Michelson interferometer ( 27 ) is excited by the “stimulus” radiation on both the measurement arm, that comprises the sensing fibre ( 34 ), and the reference arm ( 38 ) while the “pump” radiation is injected only in the measurement arm by a controllable inhibition system ( 57 ). The output of the interferometer ( 27 ) is analysed in the frequency domain differential detectors ( 73, 74 ) sweeping the wavelength of the pump laser ( 12 ) and of the wavelength shift of the Brillouin laser ( 14 ). The invented apparatus does not require electro-optical modulators, phase-locking, high power optical amplifiers or microwave electronics and overcomes the prior art issues on manufacturing cost, stability, spatial resolution and on separate measurement of strain and temperature on the same sensor. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Patent Application Ser. No. 60/116,776 filed Jan. 22, 1999, U.S. Provisional Patent Application Ser. No. 60/116,830 filed Jan. 22, 1999, and U.S. Provisional Patent Application Ser. No. 60/119,776 filed Feb. 11, 1999 and as assigned to the assignee of this application; the priority of these provisional applications is hereby claimed.
FIELD OF THE INVENTION
The present invention relates generally to the field of disc drives, and more particularly to an apparatus and method for providing a reliable, ferrofluidic seal between a hub and a stationary shaft; the design is especially useful in a high speed spindle motor in a disc drive.
BACKGROUND OF THE INVENTION
Disc drives, including magnetic disc drives, optical disc drives and magneto-optical disc drives, are widely used for storing information. A typical disc drive has one or more discs for storing information in a plurality of concentric circular tracks. This information is written to and read from the discs using read/write heads mounted on actuator arms which are moved from track to track across surfaces of the discs by an actuator mechanism. The discs are mounted on a spindle which is turned by a spindle motor to pass the surfaces of the discs under the read/write heads. The spindle motor generally includes a shaft fixed to a baseplate and a hub, to which the spindle is attached, having a sleeve into which the shaft is inserted. Permanent magnets attached to the hub interact with a stator winding on the baseplate to rotate the hub relative to the shaft. One or more bearings between the hub and the shaft facilitate rotation of the hub.
The spindle motor also typically includes an exclusion seal to seal interfacial spaces between the hub and the shaft. This is necessary, because lubricating fluids or greases used in the bearings tend to give off aerosols or vaporous components that migrate or diffuse out of the spindle motor and into a disc chamber in which the discs are maintained. This vapor often transports other particles, such as material abraded from the bearings or other components of the spindle motor, into the disc chamber. These vapors and particles deposit on the read/write heads and the surfaces of the discs, causing damage to the discs and the read/write heads as they pass over the discs. Thus, the migration of these contaminants into the disc chamber must be prevented.
To prevent the migration of these contaminants into the disc chamber, the latest generation of spindle motors utilize a ferrofluidic seal between the shaft and the hub. Ferrofluidic seals are described in, for example, U.S. Pat. No. 5,473,484, which is incorporated herein by reference. A typical ferrofluidic seal consists of a ferrofluid, an axially polarized annular magnet and two magnetically permeable annular pole pieces attached to opposing faces of the magnet. The ferrofluid is conventionally composed of a suspension of magnetically permeable particles suspended in a fluid carrier. Generally, the magnet and the pole pieces are fixed to the hub and extend close to but do not touch the shaft. Magnetic flux generated by the magnet passes through the pole pieces and the shaft, which is also magnetically permeable, to magnetically hold the ferrofluid in magnetic gaps between the pole pieces and the shaft, thereby forming a seal.
Current design concepts for high speed ferrofluid seals (above 13K RPM) have a rotating magnetic seal with a ferrofluid liquid between the seal and a fixed shaft. The centrifugal forces developed under high speed operation exceed the ability of the seal magnetic flux to hold the ferrofluid against the shaft due to the velocity gradient across the ferrofluid, resulting in the failure of the ferrofluid to maintain a hermetic seal.
Accordingly, there is a need for a design that seals an outer surface of a shaft to an inner surface of a hub disposed about the shaft. It is desirable that the seal provide a structure that is reliable at high rotational speeds. It is also desirable that a method for forming such a ferrofluidic seal not increase manufacturing time or costs for assembling a spindle motor in which the seal is used.
In addition, the seal conductivity of ferrofluid seals is becoming marginal (>150 Mohms) for high performance drives.
The present invention provides a solution to these and other problems, and offers other advantages over the prior art.
SUMMARY OF THE INVENTION
The present invention relates to an apparatus for sealing the outer surface of a shaft to an inner surface of a hub disposed about the shaft that solves the above problems.
In summary, the present invention contemplates the use of a capillary seal adjacent a bearing race between the shaft and surrounding hub or housing. The seal may take a plurality of forms, including a straight capillary seal; a seal formed between the housing and a seal ball having different radius of curvatures (preferably with the housing internal surface having a larger radius); or a centrifugal capillary seal comprising a male cone supported on a fixed or rotating shaft, and a female cone supported on a housing.
The use of a capillary seal rather than ferrofluid seal should also provide a reduction in resistance across the seal gap compared to a ferrofluid seal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a disc drive in which a spindle motor incorporating a ferrofluidic seal according to the embodiment of the present invention is especially useful.
FIG. 2 is a sectional side view of an embodiment of a spindle motor in which the present invention is useful illustrating a ferrofluidic seal according to the prior art.
FIGS. 3A and 3B are partial sectional views of the upper section of the spindle motor of FIG. 2 showing an embodiment of the ferrofluid seal according to the present invention.
FIGS. 4A and 4B are partial sectional views of a capillary seat in accord with this invention.
FIG. 5 is a vertical sectional view of an alternate embodiment of the invention.
FIG. 6 illustrates a method of assembly of the design of FIG. 5 .
FIGS. 7A-7C illustrates a further assembly method utilizing deformation of parts.
FIGS. 8A-8C illustrates further assembly methods utilizing multiple parts.
DETAILED DESCRIPTION
FIG. 1 is a plan view of a magnetic disc drive for which a spindle motor having a seal according to the present invention is particularly useful. Referring to FIG. 1, a disc drive 100 typically includes a housing 105 having a base 110 joined to a cover 115 . One or more of discs 130 having surfaces 135 covered with a magnetic media (not shown) for magnetically storing information are attached to a spindle 140 . A spindle motor (not shown in this figure) turns the spindle 140 to rotate the discs 130 past read/write heads 145 which are suspended above surfaces 135 of the discs by a suspension arm assembly 150 . In operation, the discs 130 are rotated at high speed past the read/write heads 145 while the suspension arm assembly 150 moves the read/write heads in an arc over a number of radially spaced tracks (not shown) on the surfaces 135 of the discs 130 . Thus, the read/write heads 145 are enabled to read and write magnetically encoded information to the magnetic media on the surfaces 135 of the discs 130 at selected locations.
FIG. 2 is a sectional side view of a spindle motor 155 of a type which is especially useful in disc drives 100 . Typically the spindle motor 155 includes a rotatable hub 160 having an inner surface 165 disposed about an outer surface 170 of a shaft 175 . A ferrofluidic seal 185 according to the present invention seals and electrically connects the outer surface 170 of the shaft 175 to the inner surface 165 of the hub 160 . One or more magnets 190 attached to a periphery 195 of the hub 160 interact with a stator winding 205 attached to the base 110 to cause the hub 160 to rotate. The hub 160 is supported on the shaft 175 by one or more ball bearings 215 . A ball bearing generally includes one or more balls 220 loosely held by a retainer 225 between an inner race 230 and an outer race 235 . Interfacial spaces 245 between the balls 220 , the retainer 225 and the inner and outer races 230 , 235 , are filled with a lubricating fluid or grease to facilitate movement of the balls 220 . The structure of the ball bearing or similar bearing is not material to the invention. What is significant is that the seal adjacent the ball bearing must maintain its sealing function so that the fluid, grease and other loose particles associated with the ball bearings cannot reach the discs.
As spindle rotational speeds increase, it becomes increasingly more difficult for ferrofluid seals to retain fluid in the seal gaps without migration and splashing. In addition, the seal conductivity of ferrofluid seals is becoming marginal (>150 Mohms) for high performance drives. Therefore, a capillary seal, of the type used in FDB motors, could be used to replace a ferrofluid seal. In addition, the electrical conductivity of FDB motors has been found to be on the order of 100 Mohm or less. This can be attributed to the very small gap.
Two types of capillary seals were evaluated, centrifugal and straight. Centrifugal seals are being used successfully in the conical motors, but are more complicated than straight capillary seals. The seals are shown in FIGS. 3A, 3 B, 4 A, and 4 B. Both types are predicted to offer adequate sealing strength (>5 in H 2 O at 14000 rpm). The centrifugal seal (FIG. 4) derives its strength from rotation, while the straight capillary (FIG. 3) seal is a static seal.
Both seal types were configured to be direct drop-in fits to existing motor designs using convention ball bearings to support relative housing/shaft rotation.
The straight capillary seal is shown in FIG. 3A, with a more detailed version shown in FIG. 3 B. As it appears in FIG. 3A, the straight capillary seal comprises simply a tapered surface 302 which is preferentially ground into the external surface of the shaft 304 facing a relatively axially straight surface 306 supported from a shoulder 307 across a narrow gap of about 0.01-0.02 micron. A fluid 308 fills this gap and both seals the gap and provides the necessary conductivity between the housing or hub 310 and the shaft 304 to discharge any static electricity so that no static electricity builds up on the surface of the disc supported on the hub 310 . A theoretical analysis has been made of the straight capillary seal using the equation shown below and assuming an operation at 14000 rpm.
Basic formula:
Δ p =2·σ cos θ/( r o . . . r i )
σ=oil surface tension(n/m)=30e−3
θ=angle of meniscus=40 deg (0 deg for clean surface and 80 deg for Nyebar)
ri,ro=inner and outer radii of annulus
α=5°
The 5 degree taper on the straight capillary seal should preferably be on the shaft, not on the seal. It could be ground into the shaft. The seal is, therefore, easier to make. The oil is also less influenced by centrifugal force.
Results of this analysis will appear in Table I below following a discussion of the centrifugal seal. The centrifugal seal proposed for this design is shown in FIGS. 4A and 4B.
As clearly appears in FIG. 4A, the centrifugal capillary seal 400 is dropped or pressed into place between the shaft 400 and the housing or hub 402 . The seal consists simply of a cone 404 which is pressed onto the outer surface of the shaft 400 , and typically a female cone consisting of upper and lower pieces 406 , 408 . In order to achieve adequate seal alignment during installation, the male and female cones are typically of the same axial thickness. They are simultaneously pressed onto or into shaft and hub so that the top surfaces on each part are in the same plane. In a preferred assembly approach, it may be necessary to first insert the lower section 408 of the female cone either before or simultaneously with male cone piece 404 . Then the upper female cone piece 406 is pressed into place, and the two pieces 406 , 408 are adhesively bonded, welded, or otherwise fixedly joined together. The fluid 410 can then be inserted by capillary attraction or other known process. It is immediately apparent that the need for the bond or weld 409 between the upper/lower pieces 406 , 408 is to prevent the escape of any of the fluid between the upper and lower pieces as well as to maintain alignment of the seal elements.
The conical configuration was analyzed as a replacement for a ferrofluid seal at 14000 rpm using the equation and constant set forth below.
The governing equation is:
dp/ds =( dp/dr )cos θ=2(ρ)cos θ
where: dp/ds=pascals/mm
r=radius=4.1 mm
θ=seal cone average angle=30 deg
ρ=density 0.85 g/cc
=14000 rpm
As described above, both seal types are configured to be direct drop-in fits to existing motor designs such as shown in FIG. 2 using conventional ball bearings.
In both cases, the intent is that the seal contacts the outer race of the ball bearing. In the case of the straight capillary seal, the sleeve element or hub extension 310 is pressed flush against the outer race. In the case of the conical or centrifugal seal, the lower conical element 406 is pressed flush with the top of the rotating element or race. Both seals may be filled by capillary attraction.
Stiffness gradient
Pressure Capacity
Volume
Seal Type
(in H 2 O/min)
(in H 2 O)
(μl)
Centrifugal
52
13
2.19
Straight (0.01 gap)
29
7
0.32
Straight (0.02 gap)
16
4
0.45
The analysis described above was formed to establish basic geometry and performance capability. The conical seal, although more complex to insert and assemble, and possibly subject to higher electrical resistance due to larger gaps, may hold more oil which is beneficial to long life.
A further alternative is shown in FIG. 5 . As shown in this figure, a spherical seal housing 502 , which rests upon the outer race 504 of the ball bearing generally shown at 506 , cooperates with a generally spherically surfaced seal ball or ring 508 which is supported from the shaft 510 to create a conductive motor seal, which provides both a ground for the hub and back iron combination generally referenced 512 , and additionally prevents airflow through the motor.
The use of a conductive oil both between the region of the stationary seal ball 508 and the spherical seal housing 502 and the upper surface of the inner race 512 prevents particles from exiting from the bearing or the motor through the air gap, with the spherical air gap between the seal ball 508 and the seal housing 502 also being filled with fluid. The seal is formed especially with the housing and ball having different radiuses of curvature, preferably with the housing having a larger radius. It is believed that two forces maintain the integrity of the seal. First, the generally spherical shape of the seal causes the fluid to be restrained by the centrifugal forces. Secondly, the differing part radius allows for capillary forces to restrain the fluid under static conditions in the region 515 between the spherical ball 508 and the spherical housing 502 . This design offers a number of advantages including that the spherical seal (and the conical seal also described with respect to FIG. 4) offers better splash protection than either a straight conductive or ferrofluid seal. Further, with respect to this specific design of FIG. 5, the single-piece housing prevents fluid migration better than a multi-piece housing design such as found with the design of FIG. 4 .
It is also noted that the nonmagnetic nature of the fluid and seal design allows for reduction in installation constraints and frees boundary conditions. The nonmagnetic nature of the design also allows for greater selection of seal materials. Finally, the increased fluid contact area reduces seal resistance versus current HDD seals.
The seal FIG. 5 could be formed by several methods, shown in FIGS. 6, 7 and 8 . In the assembly process of FIG. 6, the raw seal housing 602 is held in place on an offset fixture 604 . A hardened seal ball 606 which will later be slipped over the shaft, is then used as a male side of a stamping operation. An upset press 608 is used to force the seal ball into place within the housing 602 , after which the assembly comprising seal ball 606 and housing 602 are slipped over the shaft and pressed against the upper ball bearing and specifically against the outer radius thereof, as shown in FIG. 5 .
An alternative approach shown in FIGS. 7A-7C would be to plastically deform the two parts, housing and seal ball into ellipses. Orienting the parts such that the narrowest part of the ball 706 (FIG. 7B) aligns with the widest section of the housing 702 (FIG. 7A) allows the parts to be merged into the combination shown in FIG. 7 C. The compressive forces that would then be removed with the two parts rotated into their final configuration, and ready to be slipped over the shaft and against the ball bearing race as described previously.
A final approach is as shown in FIGS. 8A and 8B, wherein the housing 802 as provided has a substantially greater inner radius than the outer radius of the seal ball 806 . A third inner housing piece 808 is forcibly compressed (FIG. 8B) into the region between their inner radius of the housing 802 and the outer radius of the seal ball 806 providing the substantially same configuration as shown in the above figures, especially FIG. 6 . In yet another alternative, a two-part housing (FIG. 8C) substantially similar to the approach of FIG. 4 could be utilized, with upper and lower housing pieces 902 , 904 joined to hold the seal ball 906 in place.
Yet another problem needing to be solved with respect to this invention is optimizing the conductive path between the inner and outer elements of the design.
Spindle motors for use in HDD assemblies require an electrical conduction path between the motor hub and drive base. This conduction path is used to “bleed-off” static charge buildup on the discs as they are rotated. Static charge buildup on discs is known to cause performance degradation and failure of recording heads.
Up to this point, the static charge has been bled-off through a ferrofluid seal placed between the motor shaft and the disc mounting hub. A typical ferrofluid seal application is shown on the right side of FIG. 1 . Present ferrofluid seal technology can provide an electrical resistance in the range of 10×10 6 ohm to 20×10 6 ohm (100-200 Mohm), between the motor hub and shaft. Up to this point, resistance in this range has been sufficient to discharge the static potential without degradation of recording head performance.
Recording heads for the next generation of high performance disc drives are more sensitive to static charge buildup, and therefore require lower grounding resistance between the motor hug and shaft. Specification for next generation drives require 30 Mohm or less grounding resistance.
The resistance value, R, of ferrofluid seal is a function of the fluid resistivity, P, the gap between the seal pole piece and shaft, l, and the surface area of contact between the fluid and shaft, A, by the relation
R=Pl/A
Assembly tolerances, magnetic properties, and fluid chemistry limit the capability of ferrofluid seals to the 100=200 Mohm range. It is understood that a required resistance of <30 Mohm is not achievable without causing serious reliability, cost, and performance degradation in the spindle motor.
Given typical capillary seal geometry and using resistivity values measured in an experimental mode, the resistance of the ground path can be calculated as follows:
measured on Resistivity, P=1.35×10 9 ohm·in
Radial Gap, l,=0.0002 inch
Shaft Diameter, d=0.236 inch
Length, L=0.030 inch=area=πdl=0.0226 in 2
R=Resistance=Pl/A=R=11.9×10 6 =11.9 Mohm
Ferrofluid seals are used to provide a pressure seal to prevent particle contamination in the drive. The current technology in ferrofluid seals is a pressure capacity of 500 Pa. The capillary seal geometry described in this invention is capable of 12,000 Pa pressure capacity, offering improved pressure performance over ferrofluid seal technology, and substantially reduced resistivity. | A motor or bearing which incorporates the use of a capillary seal adjacent a bearing race between the shaft and surrounding hub or housing. The seal may take a plurality of forms, including a straight capillary seal; a seal formed between the housing and a seal ball having different radius of curvatures (preferably with the housing internal surface having a larger radius); or a centrifugal capillary seal comprising a male cone supported on a fixed or rotating shaft, and a female cone supported on a housing.
The use of a capillary seal rather than ferrofluid seal should also provide a reduction in resistance across the seal gap compared to a ferrofluid seal. | 5 |
BACKGROUND OF THE INVENTION
[0001] Heavy metal bearing air pollution unit collected flyash and air pollution control unit generated scrubber residue combinations from mass burn refuse incinerators, refuse derived fuel incinerators, wood combustors, fossil fuel combustors, steel mills, foundries, and smelters may be deemed “Hazardous Waste” by the United States Environmental Protection Agency (USEPA) pursuant to 40 C.F.R. Part 261 and also deemed hazardous under similar regulations in other countries such as Japan, Switzerland, Germany, United Kingdom, Mexico, Australia, Canada, Taiwan, European Countries, India, and China, and deemed special waste within specific regions or states within those countries, if containing designated leachate solution-soluble and/or sub-micron filter-passing particle sized Lead (Pb) and other regulated heavy metals such as Arsenic (As), Barium (Ba), Cadmium (Cd), Silver (Ag), Mercury (Hg), Selenium (Se), and Chromium (Cr) above levels deemed hazardous by those country, regional or state regulators.
[0002] Scrubber residue is most commonly a lime-based solid product produced from the interaction between either dry or slurry lime as CaO or CaO—X(H20) and acid gas components derived from the combustion of refuse or fossil fuels, processing of steel, alloys and other industrial operations which generate acid emission gases such as carbon dioxide, sulfur dioxides and hydrogen chlorides, all of which are regulated under the Clean Air Act and Amendments thereto. Some scrubbers referred to as dry lime scrubbers operate by injecting a fine-powder dry semi-hydrated lime prior to a baghouse collection unit which allows lime to establish a layer onto baghouse fabric filter surfaces and thereafter allows for acid gas reaction and conversion into calcium substituted minerals such as calcium carbonates, calcium sulfates, and calcium chloride. The dry lime injection method produces, by lime usage rate and baghouse layer jet pulse removal rate design, an excess and unreacted lime content in the scrubber residue due to incomplete lime consumption by acid gas. Dry scrubbers operate at a high excess stoichiometric level to assure that acid gases are controlled to permitted levels. Most modem scrubbers use lime in a water slurry hydrated on-site in mixing units and injected into a spray tower reactor prior to the baghouse which provides for more efficient lime consumption and conversion of acid gases to solid calcium products, and thus lower lime excess remaining in the scrubber residue stream removed from the baghouse filters. Both dry and slurry scrubber methods produce excess lime in the scrubber residue. The excess lime in scrubber residue is beneficial to this patent method as the excess calcium oxide and calcium oxide acid gas reaction products act as binders, and with iron, silicates, aluminum and aggregate particles introduced by flyash addition, has a combined flyash scrubber residue blend consistency close to Portland cement.
[0003] Flyash is comprised mostly of inorganic fine particles which are entrained within the flue gas derived from a refuse or fossil fuel combustion grate or as fine particles light enough to be air entrained from a steel mill, foundry or casting operation. Flyash and scrubber residue is commonly captured and removed from the facility exhaust in a combined form within a cyclone and/or baghouse collector. Given current Clean Air Act requirements, cyclones alone do not meet the particulate and micron particulate control requirements, and thus are often removed or operated in series with a higher efficiency collection baghouse collector.
[0004] Flyash and scrubber residues are becoming more often separated from bottom ash from the combustion of refuse and coal, and thus require separate means for dust control, chemical stabilization and physical stabilization. Bottom ash from refuse combustion has become permitted for use in construction materials and roadbase in several countries such as Taiwan and Germany, and is likely to become approved in the US, Europe and Japan within the decade. Most flyash and scrubber residues remain mixed, and flyash and scrubber residues are commonly stabilized and wetted for dust control in pellet mills, pug mills or batch weigh paddle mixers which all require water injection for ash hydration and assistance for chemical stabilization as required by the country solid and hazardous waste regulations. Water injection can produce undesirable generation of off-gas reaction products such as ammonia (from excess urea found in flyash and scrubber residue which was injected in the gas stream for nitrous oxide emission control) and phosphene or hydrogen sulfide from TCLP stabilization injection of phosphates or sulfides, and acid formations such as sulfuric, hydrochloric and phosphoric produced with the water and exothermic heat due to water hydration of unreacted scrubber residue lime. The generation of such off-gas reaction products and acid formers is often caused when using phosphoric acid Pb stabilization due to a high percentage use of stabilizing acid, such as 5% to 15% by weight of FASR use of 75% H3PO4. Such current ash and scrubber residue conditioners and mixers produce a fine free flowing larger particle ash which is less fugitive than ash feedstock, and often require special reactors and air venting to limit corrosion and meet OSHA air space requirements due to the high phosphoric acid or sulfide product usage and resulting acid gas reaction products such as H2S, H3PO4 acid mist, and phosphene.
[0005] In the United States, any industrial solid waste such as collected flyash and scrubber residue can be defined as Hazardous Waste either because it is “listed” in 40 C.F.R., Part 261 Subpart D, federal regulations adopted pursuant to the Resource Conservation and Recovery Act (RCRA), or because it exhibits one or more of the characteristics of a Hazardous Waste as defined in 40 C.F.R. Part 261, Subpart C. The hazard characteristics defined under 40 CFR Part 261 are: (1) ignitability, (2) corrosivity, (3) reactivity, and (4) toxicity as tested under the Toxicity Characteristic Leaching Procedure (TCLP). 40 C.F.R., Part 261.24(a), contains a list of heavy metals and their associated maximum allowable concentrations. If a heavy metal, such as lead, exceeds its maximum allowable concentration from a solid waste, when tested using the TCLP analysis as specified at 40 C.F.R. Part 261 Appendix 2, then the solid waste is classified as RCRA Hazardous Waste. The USEPA TCLP test uses a dilute acetic acid either in de-ionized water (TCLP fluid 2) or in de-ionized water with a sodium hydroxide buffer (TCLP fluid 1). Both extract methods attempt to simulate the leachate character from a decomposing trash landfill in which the solid waste being tested for is assumed to be disposed in and thus subject to rainwater and decomposing organic matter leachate combination . . . or an acetic acid leaching condition. Waste containing leachable heavy metals is currently classified as hazardous waste due to the toxicity characteristic, if the level of TCLP analysis is above 0.2 to 100 milligrams per liter (mg/L) or parts per millions (ppm) for specific heavy metals. The TCLP test is designed to simulate a worst-case leaching situation . . . that is a leaching environment typically found in the interior of an actively degrading municipal landfill. Such landfills normally are slightly acidic with a pH of approximately 5±0.5. Countries outside of the US also use the TCLP test as a measure of leaching such as Thailand, Taiwan, and Canada. Thailand also limits solubility of Cu and Zn, as these are metals of concern to Thailand groundwater. Switzerland, Mexico, Europe and Japan regulate management of solid wastes by measuring heavy metals and salts as tested by a sequential leaching method using carbonated water simulating rainwater, synthetic rainwater and de-ionized water sequential testing. Additionally, U.S. EPA land disposal restrictions prohibit the land disposal of solid waste leaching in excess of maximum allowable concentrations upon performance of the TCLP analysis. The land disposal regulations require that hazardous wastes are treated until the heavy metals do not leach at levels from the solid waste at levels above the maximum allowable concentrations prior to placement in a surface impoundment, waste pile, landfill or other land disposal unit as defined in 40 C.F.R. 260.10.
[0006] Suitable acetic acid leach tests include the USEPA SW-846 Manual described Toxicity Characteristic Leaching Procedure (TCLP) and Extraction Procedure Toxicity Test (EP Tox) now used in Canada. Briefly, in a TCLP test, 100 grams of waste are tumbled with 2000 ml of dilute and buffered or non-buffered acetic acid for 18 hours and then filtered through a 0.75 micron filter prior to nitric acid digestion and final ICP analyses for total “soluble” metals. The extract solution is made up from 5.7 ml of glacial acetic acid and 64.3 ml of 1.0 normal sodium hydroxide up to 1000 ml dilution with reagent water.
[0007] Suitable water leach tests include the Japanese leach test which tumbles 50 grams of composited waste sample in 500 ml of water for 6 hours held at pH 5.8 to 6.3, followed by centrifuge and 0.45 micron filtration prior to analyses. Another suitable distilled water CO 2 saturated method is the Swiss protocol using 100 grams of cemented waste at 1 cm 3 in two (2) sequential water baths of 2000 ml. The concentration of lead and salts are measured for each bath and averaged together before comparison to the Swiss criteria.
[0008] Suitable citric acid leach tests include the California Waste Extraction Test (WET), which is described in Title 22, Section 66700, “Environmental Health” of the California Health & Safety Code. Briefly, in a WET test, 50 grams of waste are tumbled in a 1000 ml tumbler with 500 grams of sodium citrate solution for a period of 48 hours. The concentration of leached lead is then analyzed by Inductively-Coupled Plasma (ICP) after filtration of a 100 ml aliquot from the tumbler through a 45 micron glass bead filter.
[0009] The present invention provides an improved, safer and less costly method of flyash and scrubber residue agglomeration and reduction of the solubility of Pb, Cd, As, Cr, Hg and other heavy metals within flyash and scrubber residue combinations produced from refuse incinerators, wood combustors, fossil fuel combustors, smelters, steel mills and foundries which utilize acid gas scrubbing technology incorporating calcium oxide (Ca0) in either hydrated or non-hydrated form. Pb and other heavy metals such as Cd are controlled by the invention under TCLP, SPLP, CALWET, MEP, rainwater and surface water leaching conditions as well as under regulatory water extraction test conditions as defined by waste control regulations in Thailand, Taiwan, Japan, Canada, UK, Mexico, Switzerland, Germany, Sweden, The Netherlands and under American Nuclear Standards for sequential leaching of wastes by de-ionized water. Unlike the present invention, prior art has focused on reducing solubility of Pb in ash residues by application of stabilizers such as cement, sulfides, silicates and water soluble phosphoric acid (Forrester U.S. Pat. No. 5,245,114) and use of a water insoluble and polymer coated phosphate sources (Forrester U.S. Pat. No. 5,860,908) without definition of the optimal combinations of phosphate, silicates, sulfides, cement and water combination for low cost combined Pb, Cd, As, Cr, Hg stabilization and physical agglomeration into a free flowing dust free matrix. Stabilization and physical agglomeration with cement combination and low phosphate and sulfide without excess water introduction will avoid acid formations within ash mixing and handling equipment and off-gas water driven reaction products such as ammonia, phosphene, and hydrogen sulfide. These previous methods also fail to recognize the value of dry stabilization introduction prior to existing air pollution control equipment and ducting which eliminates the need for expensive down-stream chemical feeders and mixing devices. In-line pre-APC stabilizer introduction also provides for stabilization of all particulates produced, including sub-micron particulates, which escape the baghouse collectors by design. A major advantage of the in-line dry chemical stabilization is thus that escaped stack gas particulates are converted to a less soluble and less bioavailable form prior to emission, and thus the environmental and health risk ranking of particulates exposed to receptors in the stack plume impact areas are greatly diminished. As fixed air pollution sources are regulated as the contribution to air gaseous pollution as well as impact to receptors exposed to gas emissions and heavy metals, the reduction of heavy metal bioavailability can greatly reduce the modeled heavy metals impact in health based risk assessments, and this improve the chance that the facility will be either permitted or allowed in increase production. A majority of flyash and scrubber residue stabilization systems used to date have also benefited from the dilution of the heavy metals in flyash and scrubber residue through bottom ash mixing, and thus providing the mixture of combined ash to pass the subject regulatory leaching test. Many of the flyash and scrubber residue ash conditioning systems and stabilization mixers used to date do not form an ash matrix suitable for direct disposal, as the flyash and scrubber residue is intended for mixing with the bottom ash where it is entrained within the larger bottom ash matrix. The bottom ash in refuse incinerators is 90% to 50% of the combined ash weight depending on whether the incinerator is a mass-burn facility or a refuse-derived fuel plant which removed ferrous, glass and non-ferrous metals prior to the remaining fluff combustion. Bottom ash is always quenched after the grate combustion discharges and wet, thus providing a suitable disposal sink for flyash and scrubber residues that would otherwise remain in a potentially dusty form after simple conditioning in a pugmill, pellet or batch blending unit.
[0010] U.S. Pat. No. 5,202,033 describes an in-situ method for decreasing Pb TCLP leaching from solid waste using a combination of solid waste additives and additional pH controlling agents from the source of phosphate, carbonate, and sulfates.
[0011] U.S. Pat. No. 5,037,479 discloses a method for treating highly hazardous waste containing unacceptable levels of TCLP Pb such as lead by mixing the solid waste with a buffering agent selected from the group consisting of magnesium oxide, magnesium hydroxide, reactive calcium carbonates and reactive magnesium carbonates with an additional agent which is either an acid or salt containing an anion from the group consisting of Triple Superphosphate (TSP), ammonium phosphate, diammonium phosphate, phosphoric acid, boric acid and metallic iron.
[0012] U.S. Pat. No. 4,889,640 discloses a method and mixture from treating TCLP hazardous lead by mixing the solid waste with an agent selected from the group consisting of reactive calcium carbonate, reactive magnesium carbonate and reactive calcium magnesium carbonate.
[0013] U.S. Pat. No. 4,652,381 discloses a process for treating industrial wastewater contaminated with battery plant waste, such as sulfuric acid and heavy metals by treating the waste waster with calcium carbonate, calcium sulfate, calcium hydroxide to complete a separation of the heavy metals. However, this is not for use in a solid waste situation.
SUMMARY OF THE INVENTION
[0014] The present invention discloses a Pb, Cd, As, Cr, and Hg bearing flyash and scrubber residue mixture stabilization method through contact of flyash and scrubber residue with stabilizing agents including sulfates, sulfides, carbonates, silicates, Portland cement, cement kiln dust, phosphates, and combinations thereof which are properly chosen to complement the regulated metals substitution into low solubility form minerals in combination with agglomeration which utilizes the flyash, scrubber residue and stabilizer combination physical and chemical nature as a self-binding material suitable for agglomeration without introduction of high water content into the ash and residue agglomeration device. The introduction of Portland cement has also been found to complement the agglomeration of the flyash scrubber residue while also reducing the amount of more costly chemical stabilizer required to meet regulatory limits.
[0015] It is anticipated that this method can be used for both reactive compliance and remedial actions as well as proactive leaching reduction means such that generated ash and residue does not exceed hazardous waste criteria. The preferred method of application of stabilizer agents would be in-line within the ash and residue collection units, and thus allowed under USEPA regulations (RCRA) as totally enclosed, in-line exempt method of TCLP stabilization without the need for a RCRA Part B hazardous waste treatment and storage facility permit.
DETAILED DESCRIPTION
[0016] Environmental regulations throughout the world such as those developed by the USEPA under RCRA and CERCLA require heavy metal bearing waste and material producers to manage such materials and wastes in a manner safe to the environment and protective of human health. In response to these regulations, environmental engineers and scientists have developed numerous means to control heavy metals, mostly through chemical applications which convert the solubility of the material and waste character to a less soluble form, thus passing leach tests and allowing the wastes to be either reused on-site or disposed at local landfills without further and more expensive control means such as hazardous waste disposal landfills or facilities designed to provide metals stabilization. The primary focus of scientists has been on reducing solubility of heavy metals such as lead, cadmium, chromium, arsenic and mercury, as these were and continue to be the most significant mass of metals contamination in our environment. Materials such as paints, cleanup site wastes such as battery acids, and industrial operations produced ash and scrubber wastes from fossil fuel combustors, smelters and incinerators are major lead sources.
[0017] Scrubber residue is most commonly a lime-based solid product produced from the interaction between either dry or slurry lime as CaOH or CaOH(x) and acid gas components derived from the combustion of refuse , wood or fossil fuels, processing of steel, smelters, and foundries and other industrial operations which generate gases as sulfur dioxides and hydrogen chlorides regulated under the Clean Air Act and Amendments thereto. Some scrubbers referred to as dry lime scrubbers operate by injecting a fine-powder dry lime prior to a baghouse collection unit, which produces a high level of excess lime in the scrubber residue due to incomplete lime consumption by acid gas. Most scrubbers use a wet slurry lime, hydrated on-site in mixing units and injected into a spray tower which provides for a very efficient lime consumption and lower lime excess remaining in the scrubber residue stream. Both scrubber methods produce excess lime and thus a residue with exothermic nature upon hydration.
[0018] There exists a demand for improved and less costly control methods of soluble lead and regulated heavy metals from flyash and scrubber residues that allows for Pb and metals stabilization into stable minerals such as phosphate apatite or lead silicate without the high costs of single stabilizer addition such as phosphoric acid or sulfides and the control requirements of such for acids and off-gas reaction products. The present invention discloses a Pb and metals bearing flyash and scrubber residue mixture ash stabilization method through contact with stabilizing agent including phosphates, cements, cement kiln dust, silicates, sulfides, sulfates, carbonates, and combinations thereof, and physical agglomeration for dusting control and separate ash and scrubber residue handling and disposal.
[0019] It is anticipated that the method can be used for RCRA compliance actions such that generated waste does not exceed appropriate TCLP hazardous waste criteria, and under TCLP or CERCLA (Superfund) response where stabilizers are added to waste piles or storage vessels previously generated. The preferred method of application of stabilizers would be in-line within the ash and residue handling systems, and thus allowed under RCRA as a totally enclosed, in-line or exempt method of TCLP stabilization without the need for a RCRA Part B hazardous waste treatment and storage facility permit(s).
[0020] The stabilizing agents including silicates, sulfates, sulfides, carbonates, cement, cement kiln dust, calcium phosphates, phosphates, and combinations thereof with the phosphate group including but not limited to wet process amber phosphoric acid, wet process green phosphoric acid, aluminum finishing Coproduct blends of phosphoric acid and sulfuric acid, technical grade phosphoric acid, monoammonia phosphate (MAP), diammonium phosphate (DAP), single superphosphate (SSP), triple superphosphate (TSP), hexametaphosphate (HMP), tetrapotassium polyphosphate, dicalcium phosphate, tricalcium phosphate, monocalcium phosphate, phosphate rock, pulverized forms of all above dry phosphates, and combinations thereof, and combination with physical agglomeration means would be selected through laboratory treatability and/or bench scale testing to provide sufficient control of metals solubility. In certain cases, such as with the use of amber and green phosphoric acid acid, phosphates may embody sulfuric acid, vanadium, iron, aluminum and other complexing agents which could also provide for a single-step formation of heavy metal minerals and agglomeration. The stabilizer and physical control type, dose rate, contact duration, and application means would be engineered for each type of ash and scrubber residue production facility.
[0021] Although the exact stabilization formation minerals are undetermined at this time, it is expected that when lead and regulated heavy metals comes into contact with the stabilizing agents in the presence of flyash and scrubber residue and sufficient agglomeration, reaction time and energy, low extract fluid soluble minerals form such as a Pb substituted hydroxyapatite, through substitution or surface bonding, which is less soluble than the heavy metal element or molecule originally in the material or waste. The combination of sufficient stabilizer and physical agglomeration will provide a dual control method of lead and metals solubility control . . . which is important in applications where complete formation of low soluble lead and metals minerals is not achieved. Such incomplete lead and metals mineral formation environments could occur where phosphates are consumed by iron and calcium within the ash and residue, where available stabilizer levels are too low for complete Pb or metals stabilization, where stabilizer to lead and metals contact is incomplete. Varied agglomeration means will produce varied ash and scrubber stabilization contact, and thus varied stabilization results.
[0022] As leach tests used throughout the world also vary as to extractor size, sample size, tumbling method, extract fluid (i.e., water, acetic acid, citric acid, synthetic rainwater, carbonated water, distilled water), the optimum range will be obtained through varying degrees of agglomeration as well as Pb and metals stabilizer dose. One skilled in the art of laboratory treatability studies will be able to develop two-dimensional dose-response relationships for a specific ash and residue combination and specific leaching method, and thus determine the best cost means of stabilization and agglomeration combination.
[0023] Examples of suitable stabilizing agents include, but are not limited to sulfates, sulfides, silicates, cements, cement kiln dust, calcium phosphates, phosphate fertilizers, phosphate rock, pulverized phosphate rock, calcium orthophosphates, monocalcium phosphate, dicalcium phosphate, tricalcium phosphate, trisodium phosphates, natural phosphates, phosphoric acids, dry process technical grade phosphoric acid, wet process green phosphoric acid, wet process amber phosphoric acid, black phosphoric acid, merchant grade phosphoric acid, aluminum finishing phosphoric and sulfuric acid solution, hypophosphoric acid, metaphosphoric acid, hexametaphosphate, tertrapotassium polyphosphate, polyphosphates, trisodium phosphates, pyrophosphoric acid, fishbone phosphate, animal bone phosphate, herring meal, bone meal, phosphorites, and combinations thereof. Salts of phosphoric acid can be used and are preferably alkali metal salts such as, but not limited to, trisodium phosphate, dicalcium phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, tripotassium phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, trilithium phosphate, dilithium hydrogen phosphate, lithium dihydrogen phosphate or mixtures thereof. Examples of suitable agglomeration means include screw mixers, pellet mills, pug mills and rotary tumblers.
[0024] The amounts and types of stabilizing agent and agglomeration units used, according to the method of invention, depend on various factors including desired solubility reduction potential, leaching test method, desired mineral toxicity, and desired mineral formation relating to toxicological and site environmental control objectives. It has been found that addition of 20% water plus 4% dicalcium phosphate plus 10% Portland cement by weight of incinerator ash and scrubber residue with pug mill agglomeration was sufficient for TCLP Pb stabilization to less than RCRA 5.0 ppm limit. It has also been found that 20% water plus 3% wet process phosphoric acid plus 15% Portland cement by weight of incinerator ash and scrubber residue with pug mill agglomeration was sufficient for TCLP Pb stabilization to less than RCRA 5.0 ppm limit. However, the foregoing is not intended to preclude yet higher or lower usage of stabilizing agent(s), agglomeration agents, or combinations.
[0025] The examples below are merely illustrative of this invention and are not intended to limit it thereby in any way.
EXAMPLE
[0026] Mass burn refuse incinerator flyash and slurry method scrubber residue combination produced from a municipal waste incinerator facility in the United States was mixed with a standard water content of 20% required for dust control, agglomeration, and hydration for assistance of chemical mineral formations, and various weight percent combinations of wet process phosphoric acid (P), triple super phosphate (T), dicalcium phosphate (D), sodium sulfide flake (S), and Portland cement (C) to evaluate the effectiveness and cost savings of stabilizer and cement combinations and agglomeration methods. The mixtures were subjected to agglomeration in a laboratory vertical table mixing device for 15 seconds at medium speed. All samples were cured at for 24 hours and subjected to TCLP analyses Method 1311 and extract digestion by EPA method 200.7.
TABLE 1 Addition (% weight ash) TCLP Pb (ppm) Cost ($ USD/ton ash) Baseline 127.00 0 4T 16.5 12 4D 27.8 8 4P 19.0 16 4S 24.8 20 4C 58.0 4 15C 21.5 15 3T + 15C 0.8 24 Cost ($ USD) 3P + 15C 1.0 27 4D + 15C 2.2 23 4S + 15C 1.4 35 10P 0.5 40 10T 0.05 30
[0027] The foregoing results in Example 1 readily established the operability of the present process to stabilize lead and heavy metal bearing ash and scrubber residue thus reducing leachability to less than the regulatory limit. Given the effectiveness of the stabilizing agents and agglomeration in causing lead and metals to stabilize as presented in the Table 1, it is believed that an amount of the stabilization and agglomeration equivalent to less than 10% by weight of ash and scrubber residue mixtures should be effective.
[0028] While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. | This invention provides a method for stabilization of flyash and scrubber residues subject to acid and water leaching tests or leach conditions by addition of stabilizing agents and agglomeration effort, such that leaching of lead and regulated heavy metals are inhibited to desired levels. The resultant waste after stabilization and compaction is suitable for disposal as RCRA non-hazardous waste. | 2 |
BACKGROUND OF THE INVENTION
The invention herein has been developed in order to alleviate certain problems relative to the firing rates of multiple boiler marine power generating combustion control systems. Typically, a steam regulator responsive to electrical output characteristics of the boiler(s), operates fuel oil regulating valves controlling the pressure to burners for each of the boilers being controlled. The steam pressure regulator also provides a control for the air mixture which properly corresponds to the particular fuel oil pressure rating.
One of the problems associated with the control system of the prior art is that the steam pressure regulator utilized has fixed linkages which control the respective fuel regulating valves for each of the boilers in exact corresponce. Modification of the system to provide independent control of the fuel oil regulating valves is difficult to achieve in terms of both apparatus and economic requirements.
If independent control of the linkages for the respective fuel requlating valves is provided, one valve and corresponding boiler could be operated under normal firing conditions, whereas the other valve and boiler could be operated in light-off mode without first bringing the first operational boiler into correspondence with the boiler to be actuated.
Because many of the boilers in operation have over the years been modified by automation, a system for regulating the pressure to each of the boilers is desirable so that full advantage may be obtained from the automatic controls now available.
SUMMARY OF THE INVENTION
In accordance with an illustrative embodiment demonstrating features and advantages of the present invention, there is provided a control system for independently operating linkages for controlling output devices driven from a primary regulator. The linkages are extended in response to actuating means which provides motive force for shifting the relative positioning of the linkages between light-off and normal operating conditions. The linkages may thereafter be operated by the requlating means in either of their normal or extended positions so that control of one boiler is vertually independent of the other. For a better understanding of the present invention together with other and further objects thereof, reference is directed to the following description taken in connection with the accompanying drawings while its scope will be pointed out in the appended claims.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of the prior art utilizing the linkages normally associated therewith.
FIG. 2 is a view of the apparatus of the present invention with appropriate notation as to its relationship with FIG. 1.
FIG. 3a and 3b show a side view of the apparatus of FIG. 2 in respective retracted and extended positions.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 there is shown a marine power generating system 10 having at least two boilers A and B. Each of the boilers are fired by a plurality of burners 11 and 12, respectively. In addition, each of the boilers A and B have damper controls 13 and 14 driven by air volume regulators 15 and 16 over respective cables 17 and 18.
A steam pressure regulator 19 is responsive to the steam pressure output of the boilers for controlling the amount of fuel pressure to the boilers A and B over fuel oil regulating valves 20 and 21, respectively. The fuel oil regulating valves 20 and 21 are driven by power arm 22 over vertical linkage arm 23 and horizontal linkages 24.
The steam pressure regulator 19 also controls a feedback arm 26 which is coupled by a linkage 27 and 28 and 29 to vary the operation of the air volume regulators 15 and 16, respectively. The system is known as a system for regulating and testing furnace pressure at 30 and 31 and windbox flow at 32 and 33 for the respective boilers which control diaphragms 34 and 35, which in turn govern the air volume regulators 15 and 16, respectively.
In operation, steam pressure regulator 19, in response to the selected operational characteristics of the power generating system responds to actuate power arm 22 for driving linkages 23 upwardly or downwardly for controlling the fuel regulating valves 20 and 21 which in turn control the amount of fuel pressure to the boilers. It is clear from the illustration of the prior art, that the linkages 23 must move in correspondence for regulating the actuation of the fuel oil regulating valves 20 and 21 at the same rate. The apparatus of the present invention, on the other hand, is designed so that fuel oil regulating valves 20 and 21 may be actuated at different rates such that if boiler A is operating at a certain output, boiler B may be on stand-by for light-off in the event that that boiler is called into service.
Referring to FIG. 2, a one hundred series of reference numerals will be utilized to correlate corresponding elements of Fig. 1. Power arm 122 and linkages 123 operate in a similar manner to the power arm 22 and linkages 23 of FIG. 1. Linkage arms 124 are similar in function to those corresponding arms 24 in FIG. 1 as well as feedback arm 126 and 127 etc.
In the present invention relay controls 40 are separately actuated from a normally closed position to an open position upon a control signal from independent control means not shown. In the normally closed position, relays 40 have no effect on the system which operates as previously described; however, if it is desired to operate one boiler under full load condition and the other in light-off mode, one of the relays 40 will be actuated to an open position so as to change the effective operating length of its respective linkage 123.
An example of an operation of the present invention is discussed below, wherein boiler A is operating under full load with its control arm 123 (left) positioned so as to regulate the fuel oil valve 124 (left) associated therewith at a selected pressure; however, boiler B if in a light-off condition requires a substantially lower pressure for the corresponding burners 12. Under these conditions, relay 40 (right) is actuated so as to provide pressure through pneumatic lines 42 and 43 to actuate pneumatic cylinders 123 (right linkage) and 45, respectively. Fluid pressure from lines 42 and 43 causes the respective pneumatic cylinders 123 and 45 to extend, i.e. control arm 123 associated with actuating line 42 piston 44 extends downwardly whereas the piston 45 and head assembly 46 extends upwardly. Stop member is 47 associated with piston 44 engages with head assembly 46. In FIGS. 3a and 3b, this relationship can be shown such that in FIG. 3a the pneumatic cylinder 44 is in the normal position with relay 40 closed and stop member 47 displaced away from the head assembly 46. Whereas in FIG. 3b the relay 40 having been actuated to the open position causes the respective cylinder members 44 and 45 to extend downwardly and upwardly in accordance with their degrees of freedom. Thereafter, the steam pressure regulator may actuate both left and right arms 123 in correspondence in accordance with the requirements of the operational control characteristic but the linkage 123 (right) remains in the downwardmost position shown in FIG. 3b so that the boiler B may be prepared for light-off whereas the boiler A may be controlled in accordance with the requirements for fuel pressure under normal conditions. It should be noted power arm 122 drives the linkage 123 through trunion apparatus 48.
Under the system of the present invention the versatility of a multiple boiler power generating system may be fully achieved in view of the advances made in the area of automatic boiler control systems with a reliable and relatively easily adapted modification of existing systems. While there has been described what at present is considered to be the preferred embodiment of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is intended in the following claims to cover all such changes and modifications as fall within the true scope and spirit of the invention. | A control rod driven in correspondence with another regulating device may be independently extended to different positions corresponding to a selected condition while the other control arm remains at a fixed length and moves in correspondence with the driving means. | 5 |
This application is a divisional, of application Ser. No. 08/560,417, filed on Nov. 17, 1995, now U.S. Pat. No. 5,753,569
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to substrates, in particular home textiles, which have been given an oil-, water- and soil-repellant treatment, and to fluorine-containing compositions for this purpose.
Many substrates, in particular home textiles, for example carpets, acquire oil-, water- and soil-repellant properties by treating, for example, the pile of a carpet with fluorocarbon compounds.
2. Description of the Related Art
According to the literature, particularly good effects are to be obtained by mixtures of fluorocarbon compounds with various fluorine-free substances. DE-A 3 307 420 discloses a mixture of fluorocarbon compounds and organosil-sesquioxanes which are employed for carpet treatment. DE-A 2 149 292 and DE-C 3 002 369 disclose a mixture of water-insoluble fluorocarbon compounds, which, for example, can be in the form of ester or urethane, and water-insoluble polymers which are free from fluorine in the non-vinyl position and have main transition temperatures above 45° C. or 25° C., respectively. Main transition temperatures are melting points or glass transition temperatures. According to DE-A 2 149 292 and DE-C 3 002 369, preferred water-insoluble polymers having a glass transition temperature above 45° C. are, for example, polymethyl methacrylate or poly(methyl methacrylate-co-ethyl methacrylate). It is emphasized here that the compositions for prevention of embedding of dirt should be neither tacky nor rubbery. Common disadvantages of the treatment compositions mentioned are that large amounts of the fluorocarbon-containing compositions, based on the carpet fibre weight, must be employed to achieve good oil-, water- and soil-repellant properties. It is also a disadvantage of the abovementioned treatment compositions that the water-repellant properties of the treated textile floor coverings are not adequate for increased requirements (for example water/isopropanol repellancies greater than 50/50: cf. embodiment examples), even when large amounts are employed. Another disadvantage is that after the treatment with the abovementioned fluorine-containing treatment agents, the textile floor coverings must be heated to at least 70° C., but usually to 100° to 130° C., to acquire the desired effects. However, heat treatments at elevated temperature are expensive and are therefore undesirable, and are sometimes harmful to certain carpet constructions. The treatment compositions according to DE-A 2 149 292 and DE-C 3 002 369 furthermore have the disadvantage that only certain treatment methods produce satisfactory results. However, the treatment method used depends on the treatment plant available and thus cannot be determined beforehand.
EP 552 630 and EP 554 667 furthermore disclose treatment compositions for various substrates which are based only on fluorine-containing copolymers and therefore require higher deposits of the expensive fluorine components on the substrates.
SUMMARY OF THE INVENTION
The invention is therefore based on the object of providing substrates which have been provided with an oil-, water- and soil-repellant treatment and to compositions for their oil-, water- and soil-repellant treatment, in particular for the treatment of home textiles, which achieve good effects with significantly smaller amounts of the expensive fluorocarbon compounds, based on the substrate weight. The compositions according to the invention should furthermore impart to the substrates, in particular the home textiles, water-repellant actions which meet increased requirements. Another object comprises providing treatment compositions with which the heat treatment can be carried out at the lowest temperature or, preferably, no heat treatment is necessary. It is also desirable for the treatment agent to give good results by all the customary and known treatment methods.
It has now been found, surprisingly, that aqueous dispersions whose constituents other than water are mixtures of fluorine-containing acrylic polymers (component A) and fluorine-free poly(meth)acrylates (component B) are suitable compositions for oil-, water- and soil-repellant treatment of substrates, in particular home textiles, and solve the abovementioned problems. It has furthermore been found that all the customary treatment methods are suitable for imparting good oil-, water- and soil-repellant properties to substrates, in particular home textiles, if the substrates are treated with the compositions according to the invention. This is surprising, since the components A used for the present invention have a glass transition temperature below 25° C. and are in rubbery and in some cases tacky form at room temperature.
The invention relates to substrates from the group consisting of naturally occuring and synthetic textiles and their mixtures, leather, mineral substances, thermoplastic and thermosetting polymers and paper, which are treated with fluorine-containing compositions of the type mentioned below in an amount of 10 to 10,000 ppm, preferably 50 to 5,000 ppm, particularly preferably 100 to 2,000 ppm, calculated as fluorine and based on the total weight of substrates provided with an oil-, water- and soil-repellant treatment.
The invention furthermore relates to compositions for oil-, water- and soil-repellant treatment of substrates, comprising two components A and B, and to aqueous dispersions thereof, the constituents of which, other than water, represent 5-50% of the total weight of the dispersions and in which component A is a fluorine-containing acrylic polymer which comprises the following weight contents of comonomers, based on the total weight of A:
a) 40 to 85% by weight of (meth)acrylates containing perfluoroalkyl groups, of the formula
C.sub.n F.sub.2n+1 --X--O--CO--CR.sup.1 ═CH.sub.2 (I),
b) 1 to 45% by weight of one or more monomers from the group consisting of styrene, acrylonitrile, vinyl acetate, vinyl propionate and monomers of the formula
CH.sub.2 ═CR.sup.4 --CO--OR.sup.5 (II),
c) 4 to 30% by weight of monomers of the formula ##STR1## d) 1 to 15% by weight of ionic or ionizable monomers which either contain an amine or a carboxyl function, of the formula
CH.sub.2 ═CR.sup.11 COOCH.sub.2 CH.sub.2 N(R.sup.9, R.sup.10)(IVa),
or are in quaternized form, of the formula
CH.sub.2 ═CR.sup.11 --COO--CH.sub.2 CH.sub.2 N(R.sup.9 R.sup.10 R.sup.12)!⊕Y⊖ (IVb)
or are in N-oxidized form, of the formula ##STR2## or of the formula
CH.sub.2 ═CR.sup.13 --COO⊖Z⊕ (V),
wherein, in the formulae,
n represents a number from 4 to 20, preferably 6 to 16, or a mixture of two or more of these numbers,
X represents --(--CH 2 --) m --, --SO 2 --NR 2 --CH 2 --CHR 3 -- or --O--(--CH 2 --) m --, wherein m denotes a number from 1 to 4, preferably 2,
R 1 , R 3 , R 4 , R 6 , R 7 , R 11 and R 13 independently of one another represent hydrogen or methyl,
R 2 , R 9 , R 10 and R 12 independently of one another denote C 1 -C 4 -alkyl,
R 5 represents C 1 -C 22 -alkyl,
R 8 denotes hydrogen or C 1 -C 8 -alkyl,
p represents a number from 1 to 50, or represents a mixture of two or more numbers,
Y.sup.⊖ represents one equivalent of a mono- to trivalent anion and
Z.sup.⊕ denotes the proton H⊕ or one equivalent of a monovalent cation;
and component B is a fluorine-free poly(meth)acrylate of one or more comonomers of the formula
CH.sub.2 ═CHR.sup.14 --COO--R.sup.15 (VI)
or polyacrylonitrile with 0 to 20% by weight of comonomer (VI), in which
R 14 denotes hydrogen or methyl and
R 15 represents C 1 -C 22 -alkyl,
it being possible for 0 to 20% by weight of the comonomer of the formula (VI) to be replaced by one or more comonomers from the group consisting of vinyl acetate, styrene, acrylonitrile, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate, (meth)acrylamide, N-methylol(meth)acrylamide and N-methoxymethylol(meth)acrylamide, and the weight ratio of component A to component B being in the range from 1:25 to 10:1, preferably from 1:10 to 5:1.
DETAILED DESCRIPTION OF THE INVENTION
Preferably, n in monomers of the formula (I) assumes values from 6 to 16 and, also preferably, m assumes the value 2. R 1 in monomers of the formula (I) is preferably hydrogen. The perfluoroalkyl radical (--C n F 2n+1 ) can be unbranched or branched.
Preferably, in monomers of the formula (II), R 1 denotes methyl, ethyl, propyl, butyl, hexyl or octyl, stearyl or behenyl.
Preferably, in monomers of the formula (III), R 7 denotes hydrogen and the index p denotes a number from 3 to 25.
Preferably, in monomers of the formula (IVa, b, c), R 9 and R 10 denote methyl. Preferred anions Y.sup.⊖ are chloride, acetate, 1/2 sulphate, C 1 -C 12 -aryl- or alkylsulphonate or 1/3 phosphate. Chloride, acetate and 1/3 phosphate are particularly preferred.
Mixtures of two or more substances falling under the formulae (I), (II), (III) and (IVa, b, c) or (V) can also be employed in the fluorine-containing acrylic polymers.
In addition to the monomers a), b) and c) in the abovementioned amounts, a preferred fluorine-containing acrylic polymer (component A) comprises, as monomer d), 1-15% by weight of those of the formula (V).
Preferred monomers (I), (II) and (III) have the meanings given above. In the monomer (V), Z.sup.⊕ preferably denotes Na.sup.⊕, K.sup.⊕, NH 4 .sup.⊕, H 2 N.sup.⊕ (CH 2 CH 2 OH) 2 , H 3 N.sup.⊕ CH 2 CHOH or several of these which give one equivalent as the total. Component A comprises comonomers of either the formula (IVa, b, c) or (V). Preferably, component A of the composition according to the invention comprises comonomers of the formula (IVa, b, c).
A preparation process for component A, which is stabilized cationically by incorporation of the monomer (IV a,b,c) is described in U.S. Pat. No. 5,247,008 and comprises joint polymerization, initiated by free radicals, for example in solution or suspension, and subsequent neutralization with acid. The preparation process for component A, which is stabilized anionically by incorporation of the monomer (V), is in principle carried out in the same manner. If the monomer (V) is used and the proton H.sup.⊕ is present as Z.sup.⊕, however, neutralization is carried out with a base, preferably with sodium hydroxide solution, potassium hydroxide solution, aqueous ammonia, diethanolamine or monoethanolamine.
The poly(meth)acrylates (component B) preferably comprise the following comonomers of the formula (VII), it also being possible for mixtures of several substances falling under formula (VII) to be employed:
CH.sub.2 ═CR.sup.14 COOR.sup.16 (VII)
in which
R 14 denotes hydrogen or methyl and
R 16 denotes C 1 -C 4 -alkyl.
Up to 20% by weight of additional monomers, such as, for example, vinyl acetate, styrene, acrylonitrile, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate, (meth)acrylamide, N-methylol(meth)acrylamide or N-methoxymethylol(meth)acrylamide, can be incorporated into the poly(meth)acrylate of component B. A preparation process such as is described in U.S. Pat. No. 4,043,964 and DE 3 002 369 is suitable for component B.
The poly(meth)acrylate (VI) of component B can be replaced by polyacrylonitrile, which can comprise up to 20% by weight of comonomer (VI) and other monomers listed in the above section. In the case of component B where R 14 and R 15 =methyl, the main transition temperature (glass transition temperature) is 105° C. Surprisingly, heat treatment can also be dispensed with if this component is employed, and instead the product can be dried at room temperature (25° C.) after the treatment.
The weight ratio of component A to component B in the treatment composition according to the invention is in the range from 1:25 to 10:1, preferably in the range from 1:10 to 5:1.
The invention is accordingly characterized above all by the fluorine-containing compositions with components A and B with which substrates are treated.
However, in addition to the compositions according to the invention, other textile auxiliaries, which can be added even during preparation of the treatment liquor, but of course also only subsequently, can also be co-used for the treatment. Such additives which are to be mentioned are the customary creaseproofing and soft handle agents, flame retardants, oleophobizing agents, hydrophobizing agents, finishing agents, extenders for textile auxiliaries and others. It is of course also appropriate, where necessary, to co-use known hardening agents.
The following examples of such additional compositions may be mentioned: melamine condensation products such as are described, for example, in DE-A 3 800 845 and in U.S. Pat. No. 2,398,569; aqueous colloidal suspensions of organosiloxanes which are disclosed, for example, in DE-A 3 307 420.
Thus, organosilsesquioxanes such as are described, for example, in DE-B 1 594 985 or in DE-A 3 004 824 can be employed. These consist of, for example, units of the formula RSiO 3/2 (R=an optionally substituted alkyl or aryl radical having up to 7 carbon atoms) and/or of cocondensates of hydrolysates of tetraalkoxysilanes with organotrialkoxysilanes having RSiO 3/2 or SiO 2 units. These are prepared by a procedure in which, for example, silanes of the general formula R-Si(OR') 3 , by themselves or together with silanes Si(OR') 4 , wherein R is a substituted or unsubstituted hydrocarbon radical having 1 to 7 carbon atoms, the substituents of which can be halogen atoms or amino, mercapto and epoxide groups, and up to 95% of the radicals R are methyl, and R' denotes an alkyl radical having 1 to 4 carbon atoms, are added to a mixture of water, a buffer substance, a surface-active agent and if appropriate an organic solvent, with agitation and under acid or basic conditions.
The compositions according to the invention represent an improvement in the treatment of substrates, in particular home textiles, over the compositions described in DE 3 307 420, DE 2 149 292 and DE 3 002 369. Compared with compositions known from EP 552 630 and EP 554 667, the compositions according to the invention represent a considerable reduction in cost owing to the co-use of component B.
All processes which are suitable for imparting to substrates, in particular home textiles, good oil-, water- and soil-repellant properties are characterized by use of the compositions according to the invention. The base substrates on which the substrates treated according to the invention are based are, for example: linen, cotton, wool, silk, jute, polyamide, polyester, polyacrylonitrile and mixtures thereof, leather, stone slabs, floor tiles, glazed tiles, roof tiles, glass, ground surfaces of silicon, foils and films and compact workpieces of polyolefins, polyesters, polyamides, polycarbonates, polyurethanes, polyacetals, polyethers, polysulphides, polysulphones, polyimides and other thermoplastics, as well as of phenol/formaldehyde resins, urea/formaldehyde resins, melamine/formaldehyde resins and other thermosetting resins, paper and paper-like materials, such as paperboard. Preferred base substrates are home textiles based on naturally occurring and synthetic textiles and their mixtures, which are employed, for example, as carpets, curtains, decorative materials or coverings for upholstered furniture.
Processes for the treatment of such base substrates and therefore for application of the fluorine-containing compositions according to the invention are known to the expert and are, for example, dipping or spraying of the base substrates; the compositions according to the invention furthermore can be employed during the production of the base substrates, for example the pulp.
Textiles as base substrates, preferably home textiles, can be treated, for example, in the padding, spraying or foaming process.
The padder consists of a liquor trough (chassis) and at least one pair of rubber rolls. The textiles to be treated are impregnated with the treatment liquor in the chassis and squeezed off between the rolls; the superfluous liquor runs back into the chassis. It is very important that a uniform liquor pick-up is achieved over the entire width of the goods during squeezing-off. In the padding process, the liquor pick-up is stated in % of the weight of goods, and for normal textile constructions can be between 30 and 300%, depending on the quality of the goods and the padder pressure used.
In the spraying process, the textile is sprayed with the treatment liquor. The treatment liquor is finely divided by nozzles and applied uniformly. An amount of treatment liquor precisely defined beforehand is applied to one square metre of textile goods.
In the foaming process, the treatment liquor is continuously foamed mechanically in a commercially available mixer by addition of a foaming agent. The foam is produced in the mixing head by mixing the liquor with air. The foam which emerges is conveyed via a foam line to a discharge slot. The goods are pressed against the slot and taken off via a separate unit, for example a stenter frame. In the following examples, a long-chain amine oxide (Baygard® Foamer from Bayer AG) was employed as the foaming agent in a concentration of 3 g/l of treatment liquor and the degree of foaming was adjusted to 1:33. The experiments were carried out on the Kuisters Foam Applicator (=KFA unit), Ktisters, Krefeld.
After the treatment, the textiles, preferably home textiles, are dried, it being possible to use temperatures of 120° to 150° C. to achieve the desired treatment effect according to the known procedure. However, good oil-, water- and soil-repellant treatments can also be obtained with the new compositions according to the invention at significantly lower drying temperatures, for example at 25° C.
Samples of the materials thus pretreated were taken for testing of the following effects:
Oil-repellancy (according to AATCC 118-1972): The test sample is placed on a horizontal, smooth surface, a small drop (drop diameter about 5 mm) of the test liquids is applied to the test sample with the aid of a dropping pipette, and the sample is evaluated as specified after in each case 30 seconds. The AATCC oil-repellancy level of a test fabric is the highest number of that test liquid which does not wet or penetrate into the test material within a time span of 30 seconds. The test liquids and mixtures for the test method are: No. 1: Nujol or paraffin oil DAB 8; No. 2: 65% by volume of Nujol and 35% by volume of n-hexadecane; No. 3: n-hexadecane; No. 4: n-tetradecane; No. 5: n-dodecane; No. 6: n-decane; No. 7: n-octane; No. 8: n-heptane.
Repellancy towards a water/alcohol mixture (hydrophobicity): Drops of water/isopropanol mixtures (ratio 90/10 to 10/90) are applied to the test sample. The test result corresponds to the mixture with the highest isopropanol content which remains on the test sample in unchanged form for at least 20 seconds (the value 80/20, for example, is better than 20/80).
Soil repellancy (laboratory soiling test in accordance with DIN 54 324, chair castor test): Samples of the treated carpet goods were taken in accordance with the DIN specifications and soiled with 10 g of a synthetic soil. The samples were loaded in accordance with the chair castor test, which is described in detail in DIN 54 324, under a castor loading of 60 kg in total and with a change in castor pressure direction after every 50 revolutions. The test specimens are vacuumed with a vacuum cleaner (1000 watt) once with and once against the pile and evaluated visually. Test ratings are stated, higher numbers indicating an improved soil repellancy. The synthetic soil is prepared as follows:
1 932 g of chamotte
40 g of iron oxide black
20 g of iron oxide yellow
8 g of carbon black
1000 g of water
After treatment in a porcelain bead mill for 40 hours, the above mixture is dried, comminuted coarsely, ground in a powder mill and finally sieved by means of a sieving machine through a sieve having a mesh width of 10 μm.
EXAMPLES
Compositions which are not according to the invention and which represent the prior art (cf. above) are the following: Scotchgard® FC 396 (3M Comp.) according to DE-A 2 149 292 Baygard® SF-A (Bayer AG) according to DE-A 3 307 420
The compositions according to the invention are aqueous dispersions, the contents of which comprise a mixture of one or more fluorine-containing acrylate polymers (component A) and one or more poly(meth)acrylates (component B).
Preparation of the fluorine-containing acrylate polymers (component A):
Example A1
A solution of
62.0 parts by weight of CH 2 ═CHCOOCH 2 CH 2 C n F 2n+1 (mixture where n=6, 8, 10, 12, 14 or 16)
15.0 parts by weight of n-butyl acrylate,
20.0 parts by weight of ##STR3## 3.0 parts by weight of dimethylaminoethyl methacrylate in 285.0 parts by weight of acetone
was prepared in a reactor with a thermometer, stirrer and reflux condenser.
The solution was first stirred at room temperature in a nitrogen atmosphere, 2.25 parts by weight of tert-butyl perpivalate (75% strength) were then added and the mixture was kept at 73° C. under the autogenous pressure for 8 hours. After this time, the polymerization had ended. A solution of
3.9 parts by weight of acetic acid in
296.0 parts by weight of deionized water
was added to the polymer solution, which had been cooled to 50° C., at 50° C. in the course of 15 minutes. The mixture was stirred for 15 minutes and the acetone was then removed by distillation at 60° C./200-300 mbar. A stable polymer dispersion having a solids content of 25% by weight was obtained. The glass transition temperature of the polymer was -60° C. (DSC).
Example A2
A polymer based on the following monomer mixture was prepared in the same manner as in Example A1; the glass transition temperature of the polymer is -44° C. (DSC).
70.0 parts by weight of CH 2 ═C(CH 3 )COOCH 2 CH 2 C n F 2n+1 (mixture where n=6, 8, 10, 12, 14 or 16)
12.0 parts by weight of methyl methacrylate,
15.0 parts by weight of CH 2 ═CHCOO(CH 2 CH 2 O) 8 H,
3.0 parts by weight of dimethylaminoethyl methacrylate.
Preparation of a polymethacrylate (component B):
Example B
An aqueous polymethyl methacrylate dispersion was prepared as described in DE 2 149 292, Example 8, but with the difference that the solids content was adjusted to 30% by weight.
Preparation of the compositions according to the invention:
Examples 1 to 3
The compositions according to the invention were obtained by mixing components A and B as aqueous dispersions. The mixing ratios are given in the following table:
______________________________________ Component BExample Component A2 (parts by weight)______________________________________1 75 252 60 403 40 60______________________________________
Use of the compositions according to the invention:
Example I
The base substrate to be treated was a carpet (polyamide velour) having a pile weight of 600 g/m 2 . The compositions according to the invention were applied by the padding process. The treatment liquor was prepared by diluting the products according to Examples 1 to 3 with water such that, at a liquor pick-up of 100%, a fluorine deposit of 300 or 600 ppm was achieved on the carpet, based on the total weight of the carpet.
Example II
The base substrate to be treated was a carpet having a pile weight of 600 g/m 2 . The compositions according to the invention were applied by the spraying process. The treatment compositions were prepared by diluting the products according to Examples 1 to 3 with water such that, when 200 ml of liquor were sprayed onto 1 m 2 of carpet, a fluorine deposit of 300 ppm or 600 ppm was achieved on the carpet.
Example III
The base substrate to be treated was a carpet having a pile weight of 600 g/m 2 . The compositions according to the invention were applied by the foaming process. The treatment liquor was prepared by diluting the products according to Examples 1 to 3 with water such that, after a wet application of 30%, a fluorine deposit of 300 ppm or 600 ppm was achieved on the carpet. Baygard® Foamer was added as a foaming agent in a concentration of 3 g/l of treatment liquor; the degree of foaming is 1:33.
After the treatment according to Examples I to III, the carpet was dried at 120° C. and its oil-, water- and soil-repellant properties were tested.
For comparison, the products Scotchgard® FC 396 and Baygard® SF-A were employed in Examples 1 to 3 instead of the products according to Examples I to III. The results are to be found in the following Table 1.
TABLE 1__________________________________________________________________________Product according Scotchgard Baygardto Example 1 Example 2 Example 3 FC 396 SF-AFluorine deposit 300 ppm 600 ppm 300 ppm 600 ppm 300 ppm 600 ppm 300 ppm 600 ppm 300 ppm ./.__________________________________________________________________________Example I(padding process)Oleophobicity 5 5 5 5-6 5 5-6 1 1 4Hydrophobicity 80/20 80/20 80/20 80/20 80/20 80/20 15/85 15/85 45/55Soiling n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d.Example II(spraying process)Oleophobicity 3 6 1-2 2-3 5 5-6 3 4 3Hydrophobicity 35/65 80/20 45/55 50/50 80/20 80/20 30/70 40/60 30/70Soiling 2-3 2-3 2-3 2-3 2-3 2-3 3-4 3-4 3-4Example III(foaming process)Oleophobicity 3-4 4-5 2 3-4 3-4 6 2-3 5 2Hydrophobicity 80/20 80/20 80/20 80/20 80/20 80/20 20/80 40/60 20/80Soiling 4 4 4 4 4 4 4 4 4__________________________________________________________________________ n.d. not determined
It can be seen with the aid of Table 1 that the compositions according to the invention (Examples 1 to 3) are clearly superior to the treatment composition Scotchgard FC 396® and Baygard SF-A®O. For a comparable fluorine deposit, the oil test ratings are at least equivalent, and in some cases clearly better. It was possible to improve the water-repellancy considerably, which reaches the very good rating of 80/20 in the majority of cases. It is furthermore advantageous that the compositions according to the invention have good oil-, water- and soil-repellancy properties after the usual treatment processes (padding, spraying and foaming process), while Scotchgard FC 396, for example, achieves unsuitable results after the padding process.
Examples 4 to 6
(Preparation of the compositions according to the invention)
The compositions according to the invention were obtained as an aqueous dispersion by mixing components A1 and B. The mixing ratios are shown in the following table:
______________________________________ Component BExample Component A1 (parts by weight)______________________________________4 56 445 50 506 40 60______________________________________
Example IV
Use of the compositions according to the invention
In the same manner as in Example 1, a polyamide velour carpet was treated by using the compositions according to Examples 4 to 6 in the padding process such that a fluorine deposit of 250 ppm was achieved on the carpet. As a comparison, component A1, which is not per se according to the invention, was employed without addition of component B. After the treatment, part of the carpet was dried at 120° C. and another part at room temperature (25° C.), and the carpet was tested for its oil-, water- and soil-repellant properties (see following Table 2).
TABLE 2__________________________________________________________________________ ScotchgardProduct Example 4 Example 5 Example 6 Example A1 FC 396 Baygard SF-AFluorine deposit 250 ppm 250 ppm 250 ppm 250 ppm 250 ppm 250 ppm__________________________________________________________________________Example IV(padding process;drying at 120° C.)Oleophobicity 5 ./. 5 4 1 4Hydrophobicity 65/35 ./. 50/50 60/40 15/85 45/55Soiling 2-3 ./. 3 2 n.d. n.d.Example IV(padding process;drying at 25° C.)Oleophobicity 5 5 5 4 0 0Hydrophobicity 80/20 80/20 50/50 80/20 0/100 0/100Soiling n.d. 3 n.d. 2 n.d. n.d.__________________________________________________________________________ n.d not determined
Table 2 shows that the carpets treated with the compositions according to the invention do not necessarily have to be dried at 120° C., but comparable results, which are surprisingly better in the case of water-repellancy, are achieved if the treated carpets are dried at room temperature (25° C.). The fact that good results are achieved at room temperatures is surprising since the main transition temperature of component B is 105° C. An expensive and sometimes damaging heat treatment can therefore be dispensed with. At the same time, it can be seen that the compositions according to the invention, which are a mixture of fluorine-containing acrylate polymers and fluorine-free poly(meth)acrylates, give better results in respect of oleophobicity and staining than the fluorine-containing acrylate polymer (Example A1) by itself.
Example V
(Use of the compositions according to the invention)
The base substrate to be treated was a polyester fabric. The compositions according to the invention were applied by the padding process. The treatment liquor was prepared by diluting the composition according to Example 5 with water such that, at a liquor pick-up of 100%, a fluorine deposit of 150 or 250 ppm was achieved on the polyester fabric.
After the treatment, the carpet was dried at room temperature (25° C.) and tested for oil-, water- and soil-repellant properties.
For comparison, the product according to Example A1, which is not per se according to the invention, was employed (see following Table 3).
Expensive and sometimes damaging heat treatments can be avoided by drying the polyester fabric at room temperature. Compared with the pure fluorocarbon (Example A1), the mixture of fluorocarbon and poly(meth)acrylate provides the advantage that, for the same fluorine deposit, less soiling of the fabric is to be detected.
TABLE 3______________________________________Product Example 5 Example A1______________________________________Fluorine deposit 150 ppm 250 ppm 150 ppm 250 ppmExample V (padding process; drying at 25° C.)Oleophobicity 15 5 4-5 5Hydrophobicity 40/60 40/60 70/30 70/30Soiling 3 3 2 2______________________________________ | Fluorine-containing compositions for treating substrates to render them oil-, water- and soll-repellant, comprising a fluorine-containing acrylic copolymer and a fluorine-free poly(meth)acrylate. | 3 |
This application is a continuation of U.S. patent application Ser. No. 11/278,671, filed Apr. 4, 2006, which is a continuation of application Ser. No. 09/495,175, filed on Feb. 1, 2000, now U.S. Pat. No. 7,185,049, which claims the benefit of U.S. Provisional Application No. 60/118,022, filed Feb. 1, 1999, the contents of which is incorporated herein by reference in its entirety. This application is also related to U.S. patent application Ser. No. 11/616,315, filed Dec. 27, 2006, the contents of which is incorporated herein by reference in its entirety.
This application includes an Appendix containing computer code that performs content description in accordance with the exemplary embodiment of the present invention. That Appendix 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 any-one of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention generally relates to audiovisual data representation. More particularly, this invention relates to integrating the descriptions of multiple categories of audiovisual content to allow such content to be searched or browsed with ease in digital libraries, Internet web sites and broadcast media, for example.
2. Description of Related Art
More and more audiovisual information is becoming available from many sources around the world. Such information may be represented by various forms of media, such as still pictures, video, graphics, 3D models, audio and speech. In general, audiovisual information plays an important role in our society, be it recorded in such media as film or magnetic tape or originating, in real time, from some audio or visual sensors, be it analogue or, increasingly, digital.
While audio and visual information used to be consumed directly by the human being, computational systems are increasingly creating, exchanging, retrieving and reprocessing this audiovisual information. Such is the case for image understanding, e.g., surveillance, intelligent vision, smart cameras, etc., media conversion, e.g., speech to text, picture to speech, speech to picture, etc., information retrieval, e.g., quickly and efficiently searching for various types of multimedia documents of interest to the user, and filtering to receive only those multimedia data items which satisfy the user's preferences in a stream of audiovisual content.
For example, a code in a television program triggers a suitably programmed VCR to record that program, or an image sensor triggers an alarm when a certain visual event happens. Automatic transcoding may be performed based on a string of characters or audible information or a search may be performed in a stream of audio or video data. In all these examples, the audiovisual information has been suitably “encoded” to enable a device or a computer code to take some action.
In the infancy of web-based information communication and access systems, information is routinely transferred, searched, retrieved and processed. Presently, much of the information is predominantly represented in text form. This text-based information is accessed using text-based search algorithms.
However, as web-based systems and multimedia technology continue to improve, more and more information is becoming available in a form other than text, for instance as images, graphics, speech, animation, video, audio and movies. As the volume of such information is increasing at a rapid rate it is becoming important to be easily to be able to search and retrieve a specific piece of information of interest. It is often difficult to search for such information by text-only search. Thus the increased presence of multimedia information and the need to be able to find the required portions of it in an easy and reliable manner, irrespective of the search engines employed, has spurred on the drive for a standard for accessing such information.
The Moving Pictures Expert Group (MPEG) is a working group under the International Standards Organization/International Electrotechnical Commission in charge of the development of international standards for compression, decompression, processing and coded representation of video data, audio data and their combination.
MPEG previously developed the MPEG-1, MPEG-2 and MPEG-4 standards, and is presently developing the MPEG-7 standard, formally called “Multimedia Content Description Interface”, hereby incorporated by reference in its entirety.
MPEG-7 will be a content representation standard for multimedia information search and will include techniques for describing individual media content and their combination. Thus, MPEG-7 standard is aiming to providing a set of standardized tools to describe multimedia content. Therefore, the MPEG-7 standard, unlike the MPEG-1, MPEG-2 or MPEG-4 standards, is not a media content coding or compression standard but rather a standard for representation of descriptions of media content. The data representing descriptions is called “meta data”. Thus, irrespective of how the media content is represented, i.e., analogue, PCM, MPEG-1, MPEG-2, MPEG-4, Quicktime, Windows Media etc, the metadata associated with this content, may in future, be MPEG-7.
Often, the value of multimedia information depends on how easily it can be found, retrieved, accessed, filtered and managed. In spite of the fact that users have increasing access to this audiovisual information, searching, identifying and managing it efficiently is becoming more difficult because of the sheer volume of the information. Moreover, the question of identifying and managing multimedia content is not just restricted to database retrieval applications such as digital libraries, but extends to areas such as broadcast channel selection, multimedia editing and multimedia directory services.
Although techniques for tagging audiovisual information allow some limited access and processing based on text-based search engines, the amount of information that may be included in such tags is somewhat limited. For example, for movie videos, the tag may reflect name of the movie or list of actors etc., but this information may apply to the entire movie and may not be sub-divided to indicate the content of individual shots and objects in such shots. Moreover, the amount of information that may be included in such tags and architecture for searching and processing that information is severely limited.
SUMMARY OF THE INVENTION
The invention provides a system and method for integrating multimedia descriptions in a way that allows humans, software components or devices to easily identify, manage, manipulate, and categorize the multimedia content. In this manner, a user who may be interested in locating a specific piece of multimedia content from a database, Internet, or broadcast media, for example, may search for and find the of the multimedia content.
In this regard, the invention provides a system and method that receives multimedia content from a multimedia stream and separates the multimedia content into separate components which are assigned to single media categories, such as image, video, audio, synthetic audiovisual, and text. Within each of the single media categories, media events are classified and descriptions of such single media events are generated. These descriptions are then integrated and formatted, according to a multimedia integration description scheme. Multimedia integration description is then generated for the multimedia content. The multimedia description is then stored into a database.
As a result, a user may query a search engine which then retrieves the multimedia integration description from the database. The search engine can then provide the user a useful search result whose multimedia integration description meets the query requirements.
The exemplary embodiment of the invention addresses the draft requirements of MPEG-7 promulgated by MPEG at the time of the filing of this patent application. That is, the invention provides object-oriented, generic abstraction and uses objects and events as fundamental entities for description. Thus, the invention provides an efficient framework for description of various types of multimedia data.
The invention is also a comprehensive tool for describing multimedia data because it uses eXtensible Markup Language (XML), which is self describing. The present invention also provides flexibility because parts can be instantiated so as to provide efficient organization. The invention also provides extensibility and the ability to define relationships between data because elements defined in the description scheme can be used to derive new elements.
These and other features and advantages of this invention are described in or are apparent from the following detailed description of the system and method according to this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiments of the invention will be described in detail with reference to the following figures wherein:
FIG. 1A is an exemplary block diagram showing a multimedia integration system;
FIG. 1B is an exemplary block diagram of an exemplary individual media type descriptor generation unit shown in FIG. 1A ;
FIG. 2 is an exemplary block diagram of the multimedia integration description scheme unit in FIG. 1A ;
FIG. 3 is an example of a multimedia stream, consisting of multimedia objects and single-media objects, and the relationship among these objects;
FIG. 4 is a UML representation of the multimedia description scheme at the multimedia stream level which consists of one or more multimedia objects;
FIG. 5 is a UML representation of the multimedia description scheme at the multimedia object level; and
FIG. 6 is an exemplary flowchart showing the process of generating integrated multimedia content description for multimedia content.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Prior to explaining the exemplary embodiment of the invention, a synopsis of MPEG-7 is provided to aid in the reader's understanding of how the exemplary embodiment processes multimedia data within the construct of MPEG-7.
MPEG-7 is the result of a global demand that has logically followed the increasing availability of digital audiovisual content. Audiovisual information, both natural and synthetic, will continue to be increasingly available from many sources around the world. Also, users want to use this audiovisual information for various purposes. However, before the information can be used, it must be identified, located, indexed, and even characterized properly. At the same time, the increasing availability of potentially interesting material makes searching more difficult because of the increasingly voluminous pool of information to be searched.
MPEG-7 is directed at standardizing the interface for describing multimedia content to allow efficient searching and retrieval for various types of multimedia material interesting to the user. MPEG-7 is meant to provide standardization of multimedia content descriptions. MPEG-7 expects to extend the limited capabilities of proprietary solutions in identifying content that exist today, notably by including more data types. In other words, MPEG-7 will specify a standard set of descriptors that can be used to describe various types of multimedia information. MPEG-7 will also specify predefined structures of descriptors and their relationships, as well as ways to define one's own structures. These structures are called description schemes (DSs). Defining new description schemes can be performed using a special language, the description definition language (or DDL), which is also a part of the MPEG-7 standard. The description, i.e., a set of instantiated description schemes, is associated with the content itself to allow fast and efficient searching for material of a user's interest. MPEG-7 will also include coded representations of a description for efficient storage, or fast access.
Conventionally, search engines each have individual syntax formats that differ. These differences in syntax format cause compatibility issues between search criteria, e.g., identical criteria used by different engines results in different results. With the use of description schemes under MPEG-7, these search engines will be able to process MPEG-7 multimedia contents regardless of the differing syntax formats to produce the same results.
The requirements of MPEG-7 apply, in principle, to both real time and non-real time applications. Also, MPEG-7 will apply to push and pull applications. However, MPEG-7 will not standardize or evaluate applications. Rather, MPEG-7 will interact with many different applications in many different environments, which means that it will need to provide a flexible and extensible framework for describing multimedia data.
Therefore, MPEG-7 will not define a monolithic system for content description. Rather, MPEG-7 will define a set of methods and tools for describing multimedia data. Thus, MPEG-7 expects to standardize a set of descriptors, a set of description schemes, a language to specify description schemes (and possibly descriptors), e.g., the description definition language, and one or more ways to encode descriptions. A starting point for the description definition language is the XML, although it is expected that the basic XML will eventually need to be customized and modified for use in MPEG-7.
The exemplary embodiment of the invention described herein with reference to FIGS. 1A-6 conforms to the requirements of the MPEG-7 standard, in its present form.
The following description of the particular embodiment of the invention uses terminology that is consistent with definitions provided in the MPEG-7 standard. The term “data” indicates audiovisual information that is described using MPEG-7, regardless of storage, coding, display, transmission, medium or technology. Data encompasses, for example, graphics, still images, video, film, music, speech, sounds, text and any other relevant audiovisual medium. Examples of such data may be found in, for example, an MPEG-4 stream, a video tape, a compact disc containing music, sound or speech, a picture printed on paper or an interactive multimedia installation on the web.
A “feature” indicates a distinctive characteristic of the data which signifies something to someone. Examples of features include image color, speed pitch, audio segment rhythm, video camera motion, video style, movie title, actors' names in a movie, etc. Examples of features of visual objects include shape, surface, complexity motion, light, color, texture, shininess and transparency.
A “descriptor” is a representation of a feature. It is possible to have several descriptors representing a single feature. A descriptor defines the syntax and the semantics of the feature representation and allows the evaluation of the corresponding feature via the descriptor value. Examples of such descriptors include color histogram, frequency component average, motion field, title text, etc.
A “descriptor value” is an instantiation of a descriptor for a given data set. Descriptor values are combined using a description scheme to form a description.
A “description scheme”, specifies the structure and semantics of relationships between its components, which may be both descriptors and description schemes. The distinction between a description scheme and a descriptor is that a descriptor contains only basic data types, as provided by the description definition language. A descriptor also does not refer to another descriptor or description scheme.
A “description” is the result of instantiating a description scheme. To instantiate a description scheme, a set of descriptor values that describe the data is structured according to a description scheme. Depending on the completeness of the set of descriptor values, the description scheme may be fully or partially instantiated. Additionally, it is possible that the description scheme may be merely incorporated by reference in the description rather than being actually present in the description. A “coded description” is a description that has been encoded to fulfill relevant requirements such as compression efficiency, error resilience, random access, etc.
The “description definition language (DDL)” is the language that allows the creation of new description schemes and, possibly, new descriptors. The description definition language also allows the extension and modification of existing description schemes.
MPEG-7 data may be physically located with the associated audiovisual material, in the same data stream or on the same storage system, but the descriptions can also be stored elsewhere. When the content and its descriptions are not co-located, mechanisms that link audiovisual material and their MPEG-7 descriptions are needed; these links must work in both directions.
The exemplary embodiment meets the present MPEG-7 requirements outlined in the present draft of MPEG-7 standard requirements. Requirements include criteria relating to descriptors, description scheme requirements, the description definition language requirements and system requirements. While the exemplary embodiment of the invention should satisfy all requirements of MPEG-7 when taken as a whole, not all requirements have to be satisfied by each individual descriptor or description scheme.
The descriptor requirements include cross-modality, direct data manipulation, data adaptation, language of text-based descriptions, linking, prioritization of related information and unique identification. Description scheme requirements include description scheme relationships, descriptor prioritization, descriptor hierarchy, descriptor scalability, temporal range description, data adaptation, compositional capabilities, unique identification, primitive data types, composite data types, multiple media types, various types of description scheme instantiations, relationships within a description scheme and between description schemes, relationship between description and data, links to ontologies, platform independence, grammar, constraint validation, intellectual property management and protection, human readability and real time support.
While a description scheme can be generated using any description definition language, the exemplary embodiment of the invention uses eXtensible Markup Language (XML) to represent the integration description scheme. XML is a useful subset of SGML. XML is easier to learn, use and implement than SGML. XML allows for self description, i.e., allows description and structure of description in the same format and document. Use of XML also allows linking of collections of data by importing external document type definitions using description schemes.
Additionally, XML is highly modular and extensible. XML provides a self describing and extensible mechanism, and although not media centric, can provide a reasonable starting basis. Another major advantage of using XML is that it allows the descriptions to be self-describing, in the sense that they combine the description and the structure of the description in the same format and document. XML also provides the capability to import external document type definitions (or DTDs), e.g., for feature descriptors, into the image description scheme document type definitions in a highly modular and extensible way.
According to the exemplary embodiment of the invention, each multimedia component description can include multimedia component objects. Each multimedia component object has one or more associated multimedia component features. The multimedia component features of an object are grouped together as being visual, audio or a relationship on semantic or media. In the multimedia component description scheme, each feature of an object has one or more associated descriptors.
The multimedia description scheme also includes specific document type definitions, also generated using the XML framework, to provide example descriptors. The document type definition provides a list of the elements, tags, attributes, and entities contained in the document, and their relationships to each other. Document type definitions specify a set of rules for the structure of a document. For example, a document type definition specifies the parameters needed for certain kinds of documents. Using the multimedia description scheme, document type definitions may be included in the file that contain the document they describe. In such a case, the document type definition is included in a document's prolog after the XML declaration and before the actual document data begins. Alternatively, the document type definition may be linked to the file from an external URL. Such external document type definitions can be shared by different documents and Web sites. In such a way, for a given descriptor, the multimedia description scheme can provide a link to external descriptor extraction code and descriptor similarity code.
Audiovisual material that has MPEG-7 data associated with it, may include still pictures, graphics, 3D models, audio, speech, video, and information about how these elements are combined in a multimedia presentation, i.e., scenario composition information. A special case of this general data type may include facial expressions and personal characteristics.
FIG. 1A is a block diagram of an exemplary multimedia description integration system 100 . The multimedia integration description system 100 includes global media description unit 110 , local media description unit 120 , integration descriptors unit 150 , multimedia integration description scheme unit 160 , and multimedia integration description generator 165 .
The global media description unit 110 includes a global description generation unit 115 which receives multimedia content and provides global descriptions to the integration descriptors unit 150 . The global descriptions provided to the integration descriptors unit 150 are descriptions that are relevant to the multimedia content as a whole, such as time, duration, space, etc. The local media description unit 120 includes description generation units for various categories of multimedia content including image description generation unit 125 , video description generation unit 130 , audio description generation unit 135 , synthetic audiovisual description generation unit 140 and text description generation unit 145 .
While FIG. 1A illustrates the relationship between the integration description scheme and five categories of single media descriptions, one skilled in the art may appreciate that these categories are exemplary and therefore, may be subdivided or reclassified into a greater or lesser number of categories. In that regard, the exemplary embodiment illustrated in FIG. 1A illustrates how multimedia content can be divided and categorized into 5 various descriptions categories.
The multimedia integration description scheme unit 160 contains description schemes for integrating one or more of the description categories. In other words, the multimedia integration description scheme unit 160 maps how image, video, audio, synthetic and/or text descriptions, as descriptions of the component objects of a multimedia object, should be combined to form the description of the composite multimedia object and to be stored for easy retrieval. The multimedia integration description scheme unit 160 also provides input to the integration descriptors unit 150 so that it can provide proper descriptor values to the multimedia integration description generator 165 .
The multimedia integration description generator 165 generates a multimedia integration description based on the one or more of the image, video, audio, synthetic and/or text descriptions received from the description generation units 125 - 145 , the descriptor values received from the integration descriptors unit 150 and the multimedia integration description scheme received from the multimedia integration description scheme unit 160 . The multimedia integration description generator 165 generates the multimedia integration description and stores the description in the database 170 .
Once the multimedia integration description has been stored, a user terminal 180 , for example, may request multimedia content from a search engine 175 . The search engine 175 then retrieves the multimedia content descriptions, whose multimedia integration descriptions meet what the user requested, from the database 170 and provides the retrieved multimedia content descriptions to the user at terminal 180 .
FIG. 1B is an exemplary block diagram of one of the individual media type descriptor generation units (i.e., the image, video, audio, synthetic and text description generation units 125 - 145 ) shown in FIG. 1A . The individual media type description generation unit 121 includes a feature extractor and descriptors representation unit 122 , an individual media type content description generator 123 , and individual media type description scheme unit 124 .
The feature extractor and descriptors representation unit 122 receives individual media type content and extract features from the content. The extracted features are represented by descriptor values which are output to the individual media type content description generator 123 . The individual media type content description generator 123 uses the individual media type description scheme provided by the individual media type description scheme unit 124 and the descriptor values provided by feature extractor and descriptors representation unit 122 to output the content description which is sent to the multimedia integration description generator 165 , shown in FIG. 1A .
FIG. 2 shows the multimedia integration scheme unit 160 . The multimedia integration scheme unit 160 interacts with a global media description scheme 115 , an image description scheme 220 , a video description scheme 230 , an audio description scheme 240 , a synthetic audiovisual description scheme 250 and a text description scheme 260 , which provide description schemes inputs to the multimedia integration description scheme 210 . The multimedia integration description scheme 210 also receives input from integration descriptors 205 .
In this manner, the integration descriptors 205 and the description schemes 215 - 260 provide individual maps for each category of multimedia content. The description schemes 220 - 260 provide description schemes for individual multimedia categories which are integrated into a composite multimedia description scheme 210 . The multimedia integration description scheme 210 is used by the multimedia integration description generator 165 to generate a multimedia integration description for the multimedia content which is then stored in the database 170 for future retrieval by search engine 175 .
The multimedia integration description scheme (or MMDS) 210 describes multimedia content which may contain composing data from different media type, such as images, natural video, audio, synthetic video, and text. The multimedia integration description scheme 210 is configured to meet the requirements for multimedia integration description schemes specified by MPEG-7, for example, and is independent of any description definition language. The multimedia integration description scheme 210 is also configured to achieve the maximum synergy with the separate description schemes, such as the image, video, audio, synthetic, and text description schemes 220 - 260 .
In the multimedia integration description scheme 210 , a multimedia stream is represented as a set of relevant multimedia objects that can be further organized by using object hierarchies. Relationships among multiple multimedia objects that can not be expressed using a tree structure are described using entity relation graphs. Multimedia objects can include multiple features, each of which can contain multiple descriptors. Each descriptor can link to external feature extraction and similarity matching code. Features are grouped according to the following categories: media features, semantic features, and temporal features.
At the same time, each multimedia object includes a set of single-media objects, which together form the multimedia object. Single-media objects are associated with features, hierarchies, entity relation graphs, and multiple abstraction levels, as described by single media description schemes (image, video, etc.). Multimedia objects are an association of multiple single-media objects, for example, a video object corresponding to a person, an audio object corresponding to his speech and the text object corresponding to the transcript.
The multimedia integration description scheme 210 includes the flexibility of the object-oriented framework which is also found in the individual media description schemes. The flexibility is achieved by (1) allowing parts of the description scheme to be instantiated; (2) using efficient categorization of features and clustering of objects (using the indexing hierarchy, for example); and (3) supporting efficient linking, embedding, or downloading of external feature descriptor and execution codes.
Elements defined in the multimedia integration description scheme 210 can be used to derive new elements for different domains. As mentioned earlier, it has been used in description scheme for specific domain (e.g., home media).
One unique aspect of the multimedia integration description scheme 210 is the capability to define multiple abstraction levels based on any arbitrary set of criteria. The criteria can be specified in terms of visual features (e.g., size), semantic relevance (e.g., relevance to user interest profile), or service quality (e.g., media features).
The multimedia integration description scheme 210 aims at describing multimedia content resulting from integration of multiple media streams. Examples of individual media streams are images, audio sequences, natural video sequences, synthetic video sequences, and text data. An example of such integrated multimedia stream is a television program that includes video (both natural and synthetic), audio, and text streams.
Under the multimedia integration scheme, a multimedia stream is represented as a set of multimedia objects that include objects from the composing media streams. Multimedia objects are organized in object hierarchies or in entity relation graphs. Relationships among two or more multimedia objects that can not be expressed in a tree structure can be described using multimedia entity relation graphs. The tree structures can be efficiently indexed and traversed, while the entity relation graphs can model general relationships.
The multimedia integration description scheme 210 builds on top of the individual media description schemes, including the image, video, audio, synthetic and text description schemes. All elements and structures used in the multimedia integration description scheme 210 are intuitive extensions of those used in individual media description schemes.
FIG. 3 is the example showing the basic elements and structures of the multimedia integration description scheme 210 . The explanation will include example XML with the specific document type definition declarations included in Appendix A. A more complete listing of the XML description of the multimedia stream in FIG. 3 is included in Appendix B.
FIGS. 4 and 5 show the graphical representation of the proposed multimedia description scheme following the UML notations. FIGS. 4 and 5 clearly show the relationships of the multimedia description scheme 210 with description schemes 220 - 260 for individual media. It should be emphasized that the same structure is used at the multimedia object level and the single-media object level for the description schemes of the individual media: image, video, etc.
The multimedia stream element (<MM_Stream>) refers to the multimedia content being described. The multimedia stream is represented as one set of multimedia objects (<MM_Object Set>, zero or more object hierarchies (<Object_Hierarchy>), and zero or more entity relation graphs (<Entity_Relation_Graph>). Each one of these elements is described in detail below.
The multimedia stream element can include a unique identifier attribute ID. Descriptions of archives containing multimedia streams will use these IDs to reference multimedia streams.
An example of use a multimedia stream element is expressed in XML follows:
<!-- A multimedia Stream -->
<MM_Stream id=“mmstream1”>
<!-- One multimedia object set -->
<MM_Object_Set> </MM_Object_Set>
<!-- Multiple object hierarchies -->
<Object_Hierarchy> </Object_Hierarchy>
...
<!-- Multiple entity relation graphs -->
<Entity_Relation_Graph> </Entity_Relation_Graph>
...
</MM_Stream>
The basic description element of the multimedia description scheme is the multimedia object element (<MM_Object>). The set of all the multimedia objects in a multimedia stream is included within the multimedia object set (<MM_Object_Set>).
A multimedia object element includes a collection of single-media objects from one or more media streams that together form a relevant entity for searching, filtering, or presentation. These single-media objects may be from the same media stream or different media streams. Usually, single-media objects are from different media (e.g., audio, video, and text). These elements are defined in the description scheme of the corresponding media and may have associated hierarchies or entity relation graphs. For purposes of discussion, the definition of multimedia object also allows single-media objects of the same media type to be used. The single-media objects in a multimedia object do not need to be synchronized in time. In the following, “single-media object” and “media object” are used interchangeably.
The composing media objects (<Image_Object>, <Video_Object>, etc) inside a multimedia object are included in a media object set element (<Media_Object_Set>). A multimedia object element can also include zero or more object hierarchy elements (<Object_Hierarchy>) and entity relation graph elements (<Entity_Relation_Graph>) to describe spatial, temporal, and/or semantic relationships among the composing media objects.
Each multimedia object can have associated multiple features and corresponding feature descriptors, as discussed above. A multimedia object can include semantic information (e.g. annotations), temporal information (e.g. duration), and media specific information (e.g. compression format).
Two types of multimedia objects are used: local and global objects. A global multimedia object element represents the entire multimedia stream. On the other hand, a local multimedia object has a limited scope within the multimedia stream, for example, an arbitrarily shaped video object representing a person and a segmented audio object corresponding to his speech. To differentiate among local and global multimedia object, the multimedia object element includes a required attribute type, whose value can be LOCAL or GLOBAL. Only one multimedia object with a GLOBAL type will be included a multimedia stream description.
Each multimedia object element can also have four optional attributes: ID, Object_Ref, Object_Node_Ref, and Entity_Node_Ref. ID (or id) is a unique identifier of the multimedia object within the multimedia stream description. When the multimedia object acts as placeholder (i.e., no feature descriptors included) of another multimedia object, Object_Ref references that multimedia object. Object_Node_Ref and Entity_Node_Ref include the lists of the identifiers of object node elements (<Object_Node>) and entity node elements (<Entity_Node>) that reference the multimedia object element, respectively.
Below, an example showing how these elements will be used in XML is included. FIG. 3 includes examples of global multimedia objects (mmog 0 ), local multimedia objects (mmol 1 , mmol 2 , etc), and media objects (aolg 0 , vog 0 , o 0 , etc). See Appendix B for the XML of the example in FIG. 3 .
<!-- A multimedia object set element -->
<MM_Object_Set>
<!-- One or more multimedia objects -->
<MM_Object type=“GLOBAL” id=“MMobjt1”
Object_Node_Ref=“ON1”
Entity_Node_Ref=“EN1”...>
<!-- A media object set -->
<Media_Object_Set> </Media_Object_Set>
<!-- Multiple object hierarchies -->
<Object_Hierarchy> </Object_Hierarchy>
...
<!-- Multiple entity relation graphs -->
<Entity_Relation_Graph> </Entity_Relation_Graph>
...
<!-- Zero or one multimedia object media feature element -->
<MM_Obj_Media_Features> </MM_Obj_Media_Features>
<!-- Zero or one multimedia object semantic feature element -->
<MM_Obj_Semantic_Features> </MM_Obj_Semantic_Features>
<!-- Zero or one multimedia object temporal feature element -->
<MM_Obj_Temporal_Features>
</MM_Obj_Temporal_Features>
</MM_Object>
<MM_Object type=“LOCAL” id=“Mmobj2”
Object_Node_Ref=“ON2 ON10”
Entity_Node_Ref=“EN2 EN4 EN7”...>
<!-- Content of MM Object -->
</MM_Object>
...
</MM_Object_Set>
The set of all the single-media object elements (<Video_Object>, <Image_Object>, etc.) composing a multimedia object are included in the media object set element (<Media_Object_Set>). Each media object refers to one type of media, such as image, video, audio, synthetic video, and text. These media objects are defined in the description scheme of the corresponding type of media. It is important to point out that the single-media objects and the multimedia objects share very similar structures at multiple levels although the features are different.
In the same fashion as the multimedia objects, relationships among single-media objects can be described using media object hierarchies or entity relation graphs. Although entity relation graphs may lack the retrieval and transversal efficiency of hierarchical structures, it is used when efficient hierarchical tree structures are not adequate to described specific relationships. Note that media object hierarchies may include media objects of different media types.
In the multimedia integration description scheme 210 , each multimedia object can contain three multimedia object feature elements that group features based on the information they convey: media (<MM_Obj_Media_Features>), semantic (<MM_Obj_Semantic_Features>), and temporal (<MM_Obj_Semantic_Features>) information. Note that features associated with spatial positions of individual media objects (e.g., positions of video objects) are included in each specific single-media object. Spatial relationships among single-media objects inside a multimedia object are described using the entity relation graphs. Table 1 includes examples of features for each feature type:
TABLE 1
Examples of feature classes and features.
Feature Class
Features
Media
Data Location, Scalable Representation, Modality
Transcoding 1
Semantic
Text Annotation 1 , Who 1 , What Object 1 ,
What Action 1 , Why 1 , When 1 , Where 1 ,
Keywords
Temporal
Duration
1 Defined in Image description scheme.
Each multimedia object feature element includes corresponding descriptor elements. Specific descriptors can include links to external extraction and similarity matching code. External document type definitions for descriptors can be imported and used in the current multimedia description scheme. In this framework, new features, types of features, and descriptors can be included in an extensible and modular way.
In Appendix A, the declarations of the following example features are included: Data_Location, Scalable_Representation, Text_Annotation, Keywords, and Duration.
Each object hierarchy element (<Object_Hierarchy>) includes one object node element (<Object_Node>). An object hierarchy element can include a unique identifier as an attribute ID, for referencing purposes. It can also include an attribute type, to describe the type of binding (e.g., semantic) expressed by the hierarchy.
At the same time, an object node element (<Object_Node>) includes zero or more object node elements forming a tree structure. Each multimedia object node references a multimedia object in the multimedia object set through an attribute, Object_Ref, by using the latter's unique identifier. Each object node element can also include a unique identifier in the form of an attribute ID. By including the object nodes' unique identifiers in their Object_Node_Ref attributes, multimedia objects can point back to object nodes referencing them. For efficient transversal of the multimedia description, this mechanism is provided to traverse from multimedia objects in the multimedia object set to corresponding object nodes in the object hierarchy and vice versa.
The hierarchy is a way to organize the multimedia objects in the multimedia object set. The multimedia objects in a multimedia stream can be organized based on different criteria: the temporal relationships, the semantic relationships, and the value of one or more features. The top object of each multimedia object hierarchy can specify the criteria followed to generate the hierarchy. An example multimedia object hierarchy is detailed in XML below:
<!-- Object hierarchy element -->
<Object_Hierarchy id=“ ”>
<!-- One object node -->
<Object_Node id=“ ” Object_Ref=“ ... ”
<!-- Multiple object nodes -->
<Object_Node id=“ ... ” Object_Ref=“ ... ” >
...
</Object_Node>
...
</Object_Node>
...
</Object_Hierarchy>
Although a hierarchy is adequate for many purposes (e.g., A is the father of B) and is efficient in retrieval, some relationships among multimedia objects can not be expressed using a hierarchical structure (e.g., A is talking to B). For purposes of this discussion, the multimedia description scheme 210 also allows the specification of more complex relations among multimedia objects using an entity relation graph.
An entity relation graph element (<Entity_Relation_Graph>) includes one or more entity relation elements (<Entity_Relation>). It has two optional attributes, a unique identifier ID, and a string to describe the binding expressed by the graph, type.
An entity relation element (<Entity_Relation>) must include one relation element (<Relation>), zero or more entity node elements (<Entity_Node>), zero or more entity node set elements (<Entity_Node_Set>), and zero or more entity relation elements (<Entity_Relation>). An optional attribute can be included in an entity relation element, type, to describe the type of relation it expresses.
Each entity node element references a multimedia object in the multimedia object set through an attribute, Object_Ref, by using the latter's unique identifier. Each entity node element can also include a unique identifier in the form of an attribute ID. By including the entity nodes' unique identifiers in their Entity_Node_Ref attributes, multimedia objects can point back to object nodes referencing them. For efficient transversal of the multimedia description, this mechanism is provided to traverse from multimedia objects in the multimedia object set to corresponding entity nodes in the ER graph and vice versa.
Hierarchies and entity relation graphs can be used to state spatial, temporal, and semantic relationships among media objects. Examples of such types of relationships are described below. In addition, the use of entity relation graphs is also described in more detail.
<Entity_Relation_Graph type=“TEMPORAL.SMIL” 1 >
<Entity_Relation type=“TEMPORAL”>
<Relation With_Respect_To=”MediaObject1”>
<Temporal_Sequential pattern=“DELAY” />
</Relation>
<Entity_Node Media_Object_Ref=“MediaObject1” />
<Entity_Node Media_Object_Ref=“MediaObject2”
Start_Time=“2” />
<Entity_Relation>
<Relation type=“TEMPORAL”>
<Temporal_Parallel />
</Relation>
<Entity_Node Media_Object_Ref=“MediaObject3” />
<!-- Optional start or end time -->
<Entity_Node Media_Object_Ref=“MediaObject4”/>
</Entity_Relation>
</Entity_Relation>
</Entity_Relation_Graph>
<Entity_Relation_Graph type=“SPATIAL.2DSTRING”>
<Entity_Relation type=“SPATIAL”>
<Relation With_Respect_To=”MediaObject1”>
<Spatial_Arrangement At_Time=“3”>
<Spatial_Relevance pattern=”Upper_Right_Of”
/>
</Spatial_Arrangement>
</Relation>
<Entity_Node Media_Object_Ref=“MediaObject1” />
<Entity_Node Media_Object_Ref=“MediaObject2” />
<Entity_Node Media_Object_Ref=“MediaObject3” />
</Entity_Relation>
<Entity_Relation type=“SPATIAL”>
<Relation With_Respect_To=”MediaObject2”>
<Spatial_Arrangement At_Time=3>
<Spatial_Relevance pattern=”Lower_Left_Of “
/>
</Spatial_Arrangement>
</Relation>
<Entity_Node Media_Object_Ref=“MediaObject3” />
<Entity_Node Media_Object_Ref=“MediaObject1” />
<Entity_Node Media_Object_Ref=“MediaObject2” />
</Entity_Relation>
</Entity_Relation_Graph>
1 In this example, SMIL temporal models are used.
The content of the relation could be particularized for each different scenario. In Appendix A, temporal, spatial, and semantic relations are included. Similar types of relations could be added as needed. Acceptable relationships for specific applications can be defined in advance. The content of this element states the relation among the entity nodes included in that entity relation element.
Many different types of relations can be declared among multiple objects in the object set; spatial (topological or directional), temporal (topological or directional), semantic are just some type examples. An example of entity relation graph was included above to show how these structures could be used to describe temporal and spatial relationships among media objects. The same example is also valid for multimedia objects (Appendix B).
FIG. 6 is an exemplary flowchart of the multimedia integration description process. The process begins in step 610 , multimedia content is received by the global description generator 115 and one or more of the image description generator 125 , video description generator 130 , audio description generator 135 , synthetic description generator 140 and the text description generator 145 . In step 620 , the multimedia components are separated and at step 630 the single media event is classified within each of the multimedia categories in the description generators 125 - 145 .
In step 640 , the description generators 125 - 145 generate descriptions from each respective multimedia category which are then forwarded to the multimedia integration description generator 165 . In step 650 , the multimedia integration description generator 165 puts the descriptions into the proper format using the multimedia integration description scheme provided by the multimedia integration description scheme unit 170 .
Then, in step 660 , the multimedia integration description generator 165 integrates the multimedia descriptions and in step 670 , the integrated descriptions are stored in database 160 . The process then ends.
While the invention has been described with reference to the embodiments, it is to be understood that the invention is not restricted to the particular forms shown in the foregoing embodiments. Various modifications and alternations can be made thereto without departing from the scope of the invention.
APPENDIX A
Document Type Definition of Multimedia Integration Description
Scheme
MM_integration_ds.dtd
<!-- Multimedia Integration Description Scheme -->
<!ELEMENT MM_Stream ( MM_Object_Set, Object_Hierarchy*,
Entity_Relation_Graph* )>
<!ATTLIST MM_Stream
id ID #IMPLIED>
<!-- This is how external DTDs are included in the current DTD -->
<!-- External Video DS DTD -->
<!ENTITY % Video_DS SYSTEM “video_ds.dtd”>
%Video_DS;
+21!—External Audio DS DTD -->
+21!ENTITY % Audio_DS SYSTEM “audio_ds.dtd”>
%Audio_DS;
<!—External Text DS DTD -->
<!ENTITY % Text_DS SYSTEM “text_ds.dtd”>
%Text_DS;
<!—External Synthetic DS DTD -- >
<!ENTITY % Synthetic_DS SYSTEM “synthetic_ds.dtd”>
%Synthetic_DS;
<!—External Image DS DTD -->
<!ENTITY % Image_DS SYSTEM “image ds.dtd”>
%Image_DS;
<!ELEMENT MM_Object_Set ( MM_Object+ )>
<!ELEMENT MM_Object ( Media_Object_Set, Object_Hierarchy*,
Entity_Relation_Graph*,
MM_Obj_Media_Features?, MM_Obj_Semantic_Features?,
MM_Obj_Temporal_Features? )>
<!ATTLIST MM_Object
Object_Type
(LOCAL|GLOBAL)
#REQUIRED
id
ID
#IMPLIED
Object_Ref
IDREF
#IMPLIED
Object_Node_Ref
IDREFS
#IMPLIED
Entity_Node_Ref
IDREFS
#IMPLIED>
<!ELEMENT Media_Object_Set ( Audio_Object | Image_Object | Video_Object |
Text_Object
Synthetic_Object )+ >
<!-- The object hierarchy and the entity relation graph are defined in the Image DS
(Proposal #480). We include them in this DTD for convenience -->
<!-- Object hierarchy element -->
<!-- The attribute type is the hierarchy binding type -->
<!ELEMENT Object_Hierarchy ( Object_Node )>
<!ATTLIST Object_Hierarchy
id
ID
IMPLIED
type
CDATA
#IMPLIED>
<!ELEMENT Object_Node ( Object_Node* )>
<!ATTLIST object_node
id
ID
#IMPLIED
Object_Ref
IDREF
#REQUIRED>
<!-- Entity relation graph element-->
<!-- Possible types of entity relations and entity relation graphs:
- Spatial: topological, directional
- Temporal: topological, directional
- Semantic -->
<!ELEMENT Entity_Relation Graph ( Entity_Relation+ )>
<!ATTLIST Entity_Relation_Graph
id
ID
#IMPLIED
type
CDATA
#IMPLIED>
<!ELEMENT Entity_Relation ( Relation, (Entity_Node | Entity_Node_Set |
Entity_Relation)* )>
<!ATTLIST Entity_Relation
type
CDATA
#IMPLIED>
<!ELEMENT Entity_Node (#PCDATA)>
<!ATTLIST Entity_Node
id
ID
#IMPLIED
Object_Ref
IDREF
#REQUIRED>
<!ELEMENT Entity_Node_Set ( Entity_Node+ )>
<!ELEMENT Relation Temporal_Parallel | Temporal_Sequential |
Spatial_Alignment | Spatial_Arrangement |
Semantic_Relation | code)*>
<!ATTLIST Relation
With_Respect_To IDREF #IMPLIED >
<!ELEMENT Temporal_Parallel EMPTY >
<!ELEMENT Temporal_Sequential EMPTY >
<!ATTLIST Temporal_Sequential
Pattern (EXACT|DELAY|PRIOR) “EXACT” >
<!ELEMENT Spatial_Alignment EMPTY >
<!ATTLIST Spatial_Alignment
Pattern (Left_Align | Right_Align |
Top_Align | Bottom_Align) “Left_Align”
At_Time CDATA #IMPLIED >
<!ELEMENT Spatial_Arrangement ( Spatial_Relevance | Spatial_Positioning )? +22
<!ATTLIST Spatial_Arrangement
At_Time CDATA #IMPLIED >
<!ELEMENT Spatial_Relevance EMPTY >
<!ATTLIST Spatial_Relevance
Pattern (Top_Of | Bottom_Of | Left_Of | Right_Of |
Upper_Left_Of | Upper_Right_Of |Lower_Left_Of |
Lower_Right_Of |
Adjacent_To | Neighboring_To | Near_By |
Within | Contained_In) “Top_Of” >
<!ELEMENT Spatial_Positioning EMPTY >
<!ATTLIST Spatial_Positioning
Horizontal_Shift CDATA #IMPLIED
Vertical_Shift CDATA #IMPLIED >
<!ELEMENT Semantic Relation (Keywords* | code*)? >
<!ELEMENT MM_Obj_Media_Features ( Data_Location?, Scalable_Representation?,
Modality_Transcoding? )>
<!ELEMENT MM_Obj_Semantic_Features ( Text_Annotation?, Keywords? )>
<!ELEMENT MM_Obj_Temporal_Features ( Duration? )>
<!ELEMENT Keywords ( Word*, Code* ) >
<!ATTLIST Keywords
No-Words
CDATA
#REQUIRED
Language
CDATA
“English”
Extraction_Manner
(AUTOMATIC|MANUAL)
“MANUAL” >
<!ELEMENT Duration (
Image_Duration?,
Audio_Duration?,
Video_Duration?,
Text_Duration?,
Synthetic_Duration? ) >
<!ATTLIST Duration
Synchronized_Overall_Duration CDATA #IMPLIED >
<!ELEMENT Image_Duration ( Time ) >
<!ELEMENT Audio_Duration ( Time ) >
<!ELEMENT Video_Duration ( Time ) >
<!ELEMENT Synthetic_Duration ( Time ) >
<!ELEMENT Text_Duration ( Time? | Alignment? ) >
<!ELEMENT Alighment EMPTY >
<!ATTLIST Alignment
with (IMAGE|AUDIO|VIDEO|SYNTHETIC) “AUDIO”>
<!ELEMENT Data_Location(
Image_Location?,
Audio_Location?,
Video_Location?,
Text_Location?,
Synthetic_Location?) >
<!ELEMENT Image_Location (location) >
<!ELEMENT Audio_Location (location) >
<!ELEMENT Video_Location (location) >
<!ELEMENT Text_Location (location) >
<!ELEMENT Synthetic_Location (location) >
<!ELEMENT Scalable_Representation (
Static_Sampled?,
Dynamic_Condensed?) >
<!ELEMENT Static_Sampled (
Image_Condensed?,
Video_Static_Pictures?,
Audio_Clips?,
Synthetic_Pictures?) >
<!ELEMENT Image_Condensed ( Location*, Image_Scl*, Image_Subsampling* ) >
<!ELEMENT Image_Subsampling ( Image_Subsampling_Para, code)* >
<!ELEMENT Image_Subsampling_Para EMPTY >
<!ATTLIST Image_Subsampling_Para
Scheme CDATA #REQUIRED
Spatial_Rate CDATA #REQUIRED
Frame_Size CDATA #IMPLIED >
<!ELEMENT Video_Static_Pictures (Key_Frame* ) >
<!ATTLIST No_KFs CDATA #REQUIRED >
<!ELEMENT Audio_Clips (Audio_Object* | Audio_Hierarchy*) >
<!ATTLIST No_Clips CDATA #REQUIRED >
<!ELEMENT Synthetic_Pictures (Key_Frame)* >
<!ATTLIST No-KFs CDATA #REQUIRED >
<!ELEMENT Dynamic_Condensed (
Visual_Condensed?,
Audio_Condensed?,
Text_Condensed?,
Synthetic_Condensed?) >
<!ELEMENT Visual_Condensed ( Location*, Video_Scl*, Video_Subsampling* ) >
<!ELEMENT Video_Subsampling ( Video_Subsampling_Para, code)* >
<!ELEMENT Video_Subsampling_Para EMPTY >
<!ATTLIST Video_Subsampling_Para
Scheme CDATA #REQUIRED
Temporal_Rate CDATA #IMPLIED
Spatial_Rate CDATA #IMPLIED
Frame_Size CDATA #IMPLIED >
<!ELEMENT Audio_Condensed ( Location*,
Audio_Compressed*,
Audio_Subsampling*,
Audio_Timescaled* ) >
<!ELEMENT Audio_Compressed ( Audio_Compress_Para, code )* >
<!ELEMENT Audio_Compress_Para EMPTY >
<!ATTLIST Audio_Compress_Para
Scheme CDATA #REQUIRED
Bitrate CDATA #IMPLIED >
<!ELEMENT Audio_Subsampling ( Audio_Subsampling_Para, code)* >
<!ELEMENT Audio_Subsampling_Para EMPTY >
<!ATTLIST Audio_Subsampling_Para
Scheme CDATA #REQUIRED
Temporal_Rate CDATA #IMPLIED >
<!ELEMENT Audio_Timescaled (Audio_Timescale_Para, code)* >
<!ELEMENT Audio_Timescale_Para EMPTY >
<!ATTLIST Audio_Timescale_Para
Scale_Rate CDATA #REQUIRED >
<!ELEMENT Text_Condensed (Text_Abstract*) >
<!ELEMENT Text_Abstract (Location*, (Text_Abstract_Para, code)*)? >
<!ATTLIST Text_Abstract
Length_In_Words CDATA #IMPLIED
Duration_In_Seconds CDATA #IMPLIED
Language CDATA “English”
Generation_Mode (AUTOMATIC|MANUAL) “MANUAL” >
<!ELEMENT Text_Abstract_Para EMPTY >
<!ATTLIST Text_Abstract_Para
Length_In_Words CDATA #IMPLIED
Language CDATA “English” >
<!ELEMENT Synthetic_Condensed (Synthetic_Location*,
(Synthetic_Condense_Para, code)*) >
<!ELEMENT Synthetic_Condense_Para EMPTY >
<!ATTLIST Synthetic_Condense_Para
Spatial_Rate CDATA #REQUIRED
Temporal_Rate CDATA #REQUIRED
Frame_Size CDATA #REQUIRED
Bitrate CDATA #IMPLIED >
<!-- Multimedia Integration DS End -->
APPENDIX B
XML for Example in FIG. 3
TigerNews.xml:
<!-- Tiger News MM Description -->
<MM_Stream id=“TigerNews5-28-1000”>
<MM_Object_Set>
<!-- Tiger News -->
<MM_Object type=“GLOBAL” id=“mmog0”
Object_Node_Ref=“mmon0”>
<MM_Obj_Semantic_Features>
<who> <concept> Anchorperson: S. Paek
</concept></who>
<what_object> <concept>The Tiger </concept>
</what_object>
<what_action>
<concept> Tiger is Feeding </concept>
</what_action>
<where> <concept> Nigeria, Africa </concept>
</where>
<when> <concept> May 28, 2000 </concept>
</when>
<why> <concept> Nature news </concept> </why>
</MM_Obj_Semantic_Features>
<MM_Obj_Temporal_Features>
<Duration> ... </Duration>
</MM_Obj_Semantic_Features>
</MM_Object>
<!-- Audio 1: Anchorperson -->
<MM_Object type=“LOCAL” id=“mmol 1”
Object_Node_Ref=“mmon 1”
Entity_Node_Ref=“mmen 1”>
<Media_Object_Set>
<!-- Global audio object -->
<Audio_Object type=“GLOBAL” id=“ao1g0”
Object_Node_Ref=“mmol1on0”>
<!-- Features of the audio object: semantics,
media, etc -->
</Audio_Object>
<!-- Introduction of news report -->
<Audio_Object type=“SEGMENT” id=“ao1s1”
Object_Node_ref=“mmol1on1”
Entity_Node_Ref=“mmol1en1”>
<!-- Features of the audio object: semantics,
media, etc -->
</Audio Object>
<!-- Comments on news -->
<Audio_Object type=“SEGMENT” id=“ao1s2”
Object_Node_ref=“mmol1on2”
Entity_Node_Ref=“mmol1en2”>
<!-- Features of the audio object: semantics,
media, etc -->
</Audio_Object>
</Media_Object_Set>
<Object_Hierarchy>
<Object_Node id=“mmol1on0”
Object_Ref=“ao1g0”>
<Object_Node id”mmol1on1”
Object_Ref=“ao1s1”/>
<Object_Node id“mmol1on0”
Object_Ref=“ao1s2”/>
</Object_Node>
</Object_Hierarchy>
<Entity_Relation_Graph type=“TEMPORAL”>
<Entity_Relation>
<Relation type=“TEMPORAL”>
<Temporal_Sequential />
</Relation>
<Entity_Node id=“mmol1en1”
Objec_Ref=“ao1s1”/>
<Entity_Node id=“mmol1en2”
Objec_Ref=“ao1s2”/>
</Entity_Relation>
</Entity_Relation_Graph>
<MM_Obj_Media_Features>
<Data_Location> ... </Data_Location>
</MM_Obj_Media_Features>
<MM_Obj_Semantic_Features> ...
</MM_Obj_Semantic_Features>
<MM_Obj_Temporal_Features> ...
</MM_Obj_Temporal_Features>
</MM_Object>
<!-- Audio 2: Tiger -->
<MM_Object type=“LOCAL” id=“mmol2”
Object_Node_Ref=“mmon2”
Entity_Node_Ref=“mmen2”>
<!-- Single-media objects and features -->
</MM Object>
<!-- Video: Tiger News' Video -->
<MM_Object type=“LOCAL” id=“mmol3”
Object_Node_Ref=“mmon3”
Entity_Node_Ref=“mmen3”>
<!-- Single-media objects and features -->
</MM_Object>
<!-- Anchorperson -->
<!-- Groups the objects related to Anchorperson across
media -->
<MM_Object type=“LOCAL” id=“mmol4” ... >
<Media_Object_Set>
<Video_Object type=“SEGMENT”
Object_Ref=“vos1” />
<Audio_Object type=“GLOBAL”
Object_Ref=“ao1g0” />
</Media_Object_Set>
</MM_Object>
<!-- Tiger -->
<MM_Object type=“LOCAL” id=“mmol5” ... >
<!-- Object and features -->
</MM_Object>
</MM_Object_Set>
<Object_Hierarchy>
<Object_Node id=“mmon0” Object_Ref=“mmog0”>
<Object_Node id=“mmon1” Object_Ref=“mmol1” />
<Object_Node id=“mmon2” Object_Ref=“mmol2” />
<Object_Node id=“mmon3” Object_Ref=“mmol3” />
</Object_Node>
<Object_Hierarchy>
<Entity_Relation_Graph type=“TEMPORAL.SMIL”>
<Entity_Relation>
<Relation_type=“TEMPORAL”>
<Temporal_Parallel />
</Relation>
<Relation_Node id =“mmen1” Object_Ref=“mmol1” />
<Relation_Node id =“mmen2” Object_Ref=“mmol2” />
<Relation_Node id =“mmen3” Object_Ref=“mmol3” />
<Entity_Relation>
<Entity_Relation_Graph>
</MM_Stream>
<!-- Tiger News MM Description --> | The invention provides a system and method for integrating multimedia descriptions in a way that allows humans, software components or devices to easily identify, represent, manage, retrieve, and categorize the multimedia content. In this manner, a user who may be interested in locating a specific piece of multimedia content from a database, Internet, or broadcast media, for example, may search for and find the multimedia content. In this regard, the invention provides a system and method that receives multimedia content and separates the multimedia content into separate components which are assigned to multimedia categories, such as image, video, audio, synthetic and text. Within each of the multimedia categories, the multimedia content is classified and descriptions of the multimedia content are generated. The descriptions are then formatted, integrated, using a multimedia integration description scheme, and the multimedia integration description is generated for the multimedia content. The multimedia description is then stored into a database. As a result, a user may query a search engine which then retrieves the multimedia content from the database whose integration description matches the query criteria specified by the user. The search engine can then provide the user a useful search result based on the multimedia integration description. | 8 |
FIELD OF THE INVENTION
This invention relates to the manufacture of capacitors, which are produced by winding dielectric strip superimposed with associated metal layers, on a rotating mandrel, usually metal.
BACKGROUND OF THE INVENTION
In the manufacture of wound capacitors the capacitor electrodes are usually provided by prior metallization of one of the dielectric strip surfaces, but the electrodes may also be provided by a metal strip interposed between non-metallized dielectric strips.
Following completion of winding of the strip, the mandrel is removed from the finished capacitor, which is cylindrical in form, and the latter is then subjected to successive processing phases.
If the strip is wound without adopting special measures, when the capacitor is removed from the mandrel, the initial wound turns of the strip, which constitute the innermost layers, do not maintain the circular form produced by the mandrel. This causes undulation in the initial part of the strip which forms the initial turns, made possible by the axial hole left in the capacitor by the mandrel, giving rise to inward projections: this modifies the characteristics of the capacitor.
The presence of these inward projections may cause considerable problems of a mechanical nature, which have a deleterious effect on the electrical characteristics of the finished product when manufacturing steps which follow winding of the strip are performed, in particular the crushing of the wound capacitor between two planes parallel to its axis to provide a flat sided capacitor.
Crushing, which is intended to flatten the capacitor, eliminating the central hole, can cause accidental bedding down of the projections which are bent over, forming folds, and small quantities of air can remain trapped inside, with detrimental effects on future performance of the capacitor. In addition, folds which fall into a position parallel to the planes between which the capacitor is pressed, cause non-uniform stratification of the rolled strip. During the flattening phase, bosses can be formed on the outer circumference of the capacitors, which are then subjected to increased pressure, and depressions, which are thus subjected to less pressure. Increased pressure in the areas corresponding to the folds, which is difficult to quantify, reduces the thickness of the dielectric strip locally, thus producing substantial reductions in the voltage needed to cause electrical breakdown in such areas. Thus a consistent circular shape of the central aperture of the wound capacitor removed from the mandrel is important for consistent characteristics of the final flattened capacitor.
European Patent No. 0007121 discusses a method for constructing a sleeve in the centre of a wound capacitor, obtained by partial fusion of the initial turns of the wound strip. This is achieved by means of a heated pad which slides on the initial wound turns, according to a preset pressure, transferring heat to the latter. As well as involving a highly complex machine, this method tends to increase the production time for each capacitor. Further, the fusion of the initial turns requires that these turns, if the capacitor is made from metallized dielectric strip, are all demetallized which increases the bulk of small capacitors.
OBJECTS OF THE INVENTION
An object of the invention is to provide an improved method for the manufacture of wound capacitors by means of winding in which initial turns of the winding are stabilised.
SUMMARY OF THE INVENTION
The above and other objects are accomplished according to the present invention by providing a method for the manufacture of wound capacitors in which dielectric strip, either metallized on one side or in combination with a metal strip, is wound onto a cylindrical mandrel. During the winding, the said mandrel is heated to a sufficiently high temperature to set the initial turns wound on the mandrel into the circular shape of the mandrel, without causing any fusion together of such turns.
A method according to the invention results in a capacitor in which the initial turns are stiffened, having sufficient mechanical strength to maintain the circular profile produced by the mandrel, even after removal of the latter from the finished wound capacitor, without fusing the initial turns together.
BRIEF DESCRIPTION OF THE DRAWINGS
There now follows a detailed description, to be read with reference to the drawing, of a method of manufacturing capacitors embodying the invention.
The drawing shows the manufacture of a capacitor by winding dielectric strip, metallised on one side, onto a cylindrical metal mandrel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawing, 1 represents a metal mandrel, consisting of two pin halves of semi-circular section with plane surfaces abutting each other, supported and rotated by mechanisms of a known type, which are not shown.
In carrying out a preferred method embodying the invention two dielectric strips 2 and 4 are wound on the mandrel 1 producing a wound capacitor 10. The metal electrodes of the capacitor, not shown, are provided by metallization of one side of each of the dielectric strips 2, 4, as is well known.
A short portion of the strips 2 and 4, at least that in contact with the spindle, is demetallized. During winding of the strips, the mandrel is heated to a temperature sufficiently high to produce setting or stablization of the spatial arrangement of the initial turns 8 without causing fusion. The temperature of the mandrel is adjusted to be appropriate for the material of the film.
The mandrel may be heated to a constant temperature or raised to a convenient temperature for a short period of time while the wound capacitor is in position on the mandrel. The temperature of the mandrel depends on a variety of factors--the material of the dielectric films, its thickness, the size of the mandrel, whether the heating is constant or variable, and, particularly where the heating is constant, the length of time for which the wound capacitor remains on the mandrel.
We prefer to use a mandrel heated to a constant temperature, and for dielectric films of conventional thickness and in conventional capacitor winding mechanisms in which the capacitor is on the mandrel for from 5 to 20 seconds (dependent on the number of turns necessary to obtain a desired capacitance), we have found the following temperatures effective:
______________________________________Polyester films 60° C.-100° C.Polypropylene films 50° C.-90° C.Polycarbonate films 70° C.-110° C.______________________________________
The setting of the turns in carrying out a process according to the invention does not require the film to be demetallized and the amount of demetallization of the initial turns is determined only by the requirements of the capacitor. Consequently smaller capacitors can be manufactured having the desired capacitance. The capacitors are of higher quality and, as the heat is applied during the winding of the capacitors, there is no increase in the cycle time of manufacture.
The action of heat stiffens the said initial turns 8, increasing the mechanical strength, which enables the said turns to maintain the circular profile produced by the mandrel 1, even after removal of the mandrel 1 from the finished capacitor 10. The stiffened turns may include some turns which are provided with metallization.
The layers of the surrounding area 9, however, remain perfectly in contact with one another, avoiding any undulation or introduction of air. When subsequent crushing of the capacitor takes place (as, for some capacitors, occurs in a further stage of manufacture), the stiffened initial turns 8, are flattened together with the surrounding layers, providing a smooth outside surface, by virtue of perfect uniform stratification of the strip.
It will be realized that if a capacitor is made from dielectric strips with an interposed metallic foil, the method just described can still be utilized.
Heating of the metal mandrel 1 can be achieved in various ways.
One way of heating the mandrel provides for the flow of a fluid, which is either liquid or gaseous, which laps the mandrel at various points or passes through ducts provided in the mandrel. This fluid, which is heated to a suitable temperature, transfers its own heat to the mandrel, thus heating the latter. A preferred form utilises hot air (at an appropriate temperature) blown on the mandrel.
A method of heating which may be preferred in some circumstances uses the mandrel as an electrical resistance: an appropriate voltage may be applied across the ends of the mandrel for a preset period of time so that an electric current flows through the mandrel thereby heating the mandrel to a desired temperature.
Alternatively the mandrel can, for example, be subjected to a variable magnetic field; eddy currents induced inside it produce heat.
According to a further variant, during rotation, the mandrel comes into contact with a fixed projection and is pressed against it with light pressure. Heat produced by friction between the fixed part and the rotating mandrel has the effect of heating the latter.
In each case it is preferable to incorporate a sensor in the mandrel by which the temperature can be controlled.
Clearly all of the above forms of heating of the mandrel, and hence of the initial wound turns of strip 2 and 4, do not involve stopping or slowing down the winding phase, or the successive phases, nor do they require the use of complex devices associated with the machine supporting and rotating the mandrel.
In addition, the electrical characteristics of capacitors 10 remain unaltered after removal of the mandrel 1, improving the quality of the capacitors, both in regard to the final cylindrical configuration and the flattened form: the advantages obtained in regard to the present state of the art are clear.
The stiffening of the initial wound turns, with consequent stabilization of the circular profile of the latter, does not involve any fusion, even partial, of the strip forming these turns, which has an extremely positive effect, as the initial turns can still be, consequently, capacitively active.
The method of the invention is particularly useful where especially thin strips 2 and 4 are used, for example in the manufacture of miniature capacitors. Further the advantages obtained are not affected by the nature of the material forming the dielectric strip. | Wound capacitors are manufactured by winding foils on a mandrel which is heated sufficiently to set the initial turns without fusing them, thus stabilizing the circular profile produced by the mandrel so that the profile is retained when the mandrel is removed from the wound capacitor. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to a ceramic sintered body having excellent strength and showing little change of dimensions produced by thermal treatment, and having a high melting point and a low thermal expansion. Especially, this invention relates to a ceramic sintered body for structural uses, e.g. as a portliner for an internal combustion engine.
Aluminum titanate is a specific ceramic having a high melting point and showing a low thermal expansion. Because of these characteristics, attempts have been made to utilize it practically. However, it is subject to the problem that its mechanical strength is low, since it is difficult to obtain a fine sintered body, and it is also subject to thermal instability in that it undergoes thermal cracking when heated up to 1250° C. Also, thermal expansion and contraction of the sintered body are affected by the thermal treatment history, and its strength is very adversely affected by repeated heating and cooling.
This thermal treatment effect is the result of the aluminum titanate crystals having anisotropic thermal expansion characteristics, with the result that fine cracks are produced in the sintered body by a thermal treatment history of cooling after heating, thereby adversely affecting the strength of the sintered body. This formation of cracks on cooling occurs every time the ceramic sintered body is subjected to heating and cooling after sintering. It therefore causes problems of loss of strength and dimensional stability, particularly in cases where the sintered body is subjected to a cyclical heat treatment.
Various additives have been introduced in attempts to ameliorate these difficulties of aluminum titanate. For example, published Japanese Patent No. SHO.56-7996 discloses low thermal expansion ceramics containing 0.05 to 10.0 weight % of at least one of silicon and zirconium, calculated as SiO 2 and ZrO 2 , with respect to the aluminum titanate. It is stated that by the introduction of prescribed contents of silicon and zirconium into this ceramic, grain growth is controlled, resulting in a ceramic which is thermally stable and which shows little strength deterioration after a history of thermal treatment.
The Journal of the Chemical Society of Japan (Nippon Kagaku Kaishi) (1981 No. 10) pages 1647 to 1655 reports the effects of various additives under the title "Effect of additives on the properties of aluminum titanate sintered bodies". This report describes the results of attempts to improve the cracking resistance in the low temperature region by blending in additives in order to suppress the growth of aluminum titanate crystals, while promoting sintering, increasing the mechanical strength and maintaining an apparent low thermal expansion. The additives investigated were Li 2 O, B 2 O 3 , SiO 2 , MgO, Cr 2 O 3 , Fe 2 O 3 , and ZrO 2 . The effect of these additives is examined and summarized. Whereas MgO, Fe 2 O 3 and ZrO 2 have the effect of increasing the density of the sintered body, Cr 2 O 3 does not necessarily increase the density. Also, although Li 2 O and B 2 O 3 showed an effect of promoting increased fineness, SiO 2 showed a sintering promoting effect.
Furthermore, published Japanese Patent No. SHO.62-32155 discloses a composite with metal incorporating a ceramic material obtained by sintering a raw material whose chemical composition is: 50 to 60 weight % Al 2 O 3 , 40 to 45 weight % TiO 2 , 2 to 5 weight % kaolin (corresponding to Al 2 O 3 .2SiO 2 ), and 0.1 to 1 weight % magnesium silicate, and having a particle size less than 0.6 micron. This patent document suggests that the thermal and mechanical properties of the aluminum titanate are improved by using a combination of aluminum silicate-containing and magnesium silicate-containing additives.
Although in such ceramic sintered bodies, various properties of the aluminum titanate are improved, for practical use there remains a need for aluminium titanate ceramics exhibiting even greater improvements in properties such as strength and thermal variation in length. For example, although it would appear that the combination of sintering adjuvants of the above-mentioned published Japanese Patent No. SHO.62-32155 is desirable, experience has shown that it is extremely difficult to obtain ceramic bodies exhibiting uniformly satisfactory strength and thermal expansion characteristics with the form of starting materials and additive contents set out in Japanese Patent No. SHO.62-32155.
SUMMARY OF THE INVENTION
It is therefore the object of the present invention to provide an aluminum titanate ceramic sintered body that has high strength, and wherein the deterioration of mechanical strength produced by a cyclic thermal treatment history is slight, without impairing the high melting point and low thermal expansion properties possessed by aluminum titanate.
With regard to strength, the value of three point bending strength is preferred to be no less than 2.5 kg/mm 2 , preferably no less than 3.0 kg/mm 2 , most preferably no less than 3.5 kg/mm 2 . The value of the Young's Modulus is preferred to be no less than 1600 kg/mm 2 , preferably more than 2000 kg/mm 2 . With regard to the thermal variation in length on cyclic heat treatment, the value of the thermal variation in length is preferred to be less than 0.33%, most preferably less than 0.25%.
These objects are achieved by providing a ceramic sintered body produced by sintering 1 to 10 weight % of magnesium oxide (MgO), and 0.5 to 10 weight % of silicon oxide (SiO 2 ), the balance being substantially aluminum titanate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As a result of repeated investigation of sintering adjuvants of aluminum titanate, the inventors discovered that a ceramic sintered body obtained by sintering aluminum titanate to which prescribed amounts of MgO and SiO 2 , respectively, had been added had excellent characteristics. Addition of MgO increases the strength of the sintered body, but, if MgO is added on its own, it produces a concomitant increase in the thermal expansion rate of the sintered body. A considerable increase in the strength of the sintered body and a low thermal expansion can be obtained if more than 0.5 weight % SiO 2 is added. So far as the effect of addition is concerned, a range up to 10 weight % is desirable. In respect of both of these, the particularly preferred range is from 1 to 6 weight %.
These sintering adjuvants are added to aluminum titanate raw material powder obtained by calcining a mixture of aluminum oxide (Al 2 O 3 ) and titanium oxide (TiO 2 ) in the prescribed proportion, and then grinding. The molar ratio of the Al 2 O 3 and TiO 2 is preferably in the range from 1.3:0.7 to 0.8:1.2. Also, the mean particle diameter of the aluminum titanate raw material powder is 0.6 to 8 microns preferably 0.6 to 7 microns. If the powder is fine, a uniform mixture is difficult to obtain.
EXAMPLES 1 THROUGH 6
Two weight % of MgO and 1 weight % of SiO 2 were blended with aluminum titanate (Al 2 TiO 5 ) raw material wherein the molar ratio of Al 2 O 3 to TiO 2 was 1.1:0.9 and the mean grain size was 2.55 microns. The mixture was then formed at a forming pressure of 1,000 kg/cm 2 , followed by sintering for 2 hours at 1,500° C. The thermal expansion rate, the thermal variation in length, and the strength were determined for the resulting sample (sample number 1). The measured values are shown in the following Table 1 together with the corresponding properties of similarly obtained samples containing different amounts of sintering adjuvants.
The "thermal variation in length" is defined as (1 max -1 min )/1 0 , expressed as a percentage, where the original length of the sample is 1 0 , its maximum length when heated from 20° C. to 1,000° C. is 1 max , and its minimum length is 1 min .
TABLE 1__________________________________________________________________________ Sample Number 1 2 3 4 5 6__________________________________________________________________________Al.sub.2 TiO.sub.5 Mean 2.55 2.55 2.55 2.55 2.55 8.06Grain Size (μm)Sintering MgO 2 2 2 1 0 0Adjuvant SiO2 1 2 4 4 0 0(weight-%) -Sintering (C.°) 1500 1500 1500 1500 1500 1500Conditions (hr) 2 2 2 2 2 2Density (g/cm.sup.3) 3.44 3.37 3.30 3.19 3.40 2.16Bending strength 5.32 4.95 5.16 3.73 1.21 0.22(kg/mm.sup.2)Thermal 1.11 × 10.sup.-6 0.47 × 10.sup.-6 0.79 × 10.sup.-6 0.98 × 10.sup.-6 0.18 × 10.sup.-6 --Expansion Rate20-1000° C.Thermal variation 0.24 0.21 0.19 0.22 0.37 --in length (%)Young's Modulus 2.9 × 10.sup.3 2.8 × 10.sup.3 2.8 × 10.sup.3 2.1 × 10.sup.3 0.5 × 10.sup.3 0.1 × 10.sup.3(kg/mm.sup.2)__________________________________________________________________________
As can be seen from Table 1, in the case of the embodiments of this invention (sample numbers 1 to 4), the bending strength and Young's modulus were larger and the thermal variation in length was smaller than in the case of the comparative examples (sample numbers 5 and 6).
EXAMPLES 7 THROUGH 22
Sintering was carried out 2 hours at 1,500° C. after forming samples in each case at a forming pressure of 1,000 kg/cm 2 , varying the blending amounts of MgO and SiO 2 sintering adjuvants and using aluminum titanate raw material having an Al 2 O 3 :TiO 2 molar ratio of 1.1:0.9 (Al 2 TiO 5 ), but with different mean grain sizes, obtained by varying the grinding period of the raw material. The three point bending strength, thermal expansion rate (20 to 1,000° C.), thermal variation in length, and Young's Modulus were measured for the resulting samples. The results ar shown in Tables 2 to 5.
TABLE 2______________________________________Three Point Bending Strength: (kg/mm.sup.2)Adjuvant (wt. %) Mean Grain Size (μm)No. MgO SiO.sub.2 8.06 6.54 4.29 2.55 1.54______________________________________ 7 0 0 0.22 0.15 1.28 1.21 -- 8 0 1 0.54 0.60 1.24 1.88 -- 9 0 2 0.54 0.77 1.94 1.78 --10 0 4 0.80 1.02 1.81 2.76 --11 1 0 1.33 1.90 1.64 2.93 --12 2 0 1.68 1.98 2.40 3.30 --13 1 1 2.37 3.71 4.10 3.46 5.0714 1 2 2.61 3.42 3.21 3.18 4.6615 1 4 2.77 3.06 3.42 3.73 4.7916 2 1 3.36 3.99 5.00 5.32 5.5317 2 2 3.14 4.08 4.38 4.95 5.1718 2 4 2.48 3.30 4.31 5.16 5.2419 2 6 -- -- -- 4.70 5.7020 4 1 -- -- -- 5.32 5.7821 4 2 -- -- -- 4.83 5.5122 4 4 -- -- -- 4.17 4.31______________________________________
TABLE 3______________________________________Thermal Expansion Rate: (× 10.sup.-6)Adjuvant (wt. %) Mean Grain Size (μm)No. MgO SiO.sub.2 4.29 2.55 1.54______________________________________ 7 0 0 -1.13 - 0.18 -- 9 0 2 -- 0.47 --12 2 0 -- 1.02 --13 1 1 -- -- 0.8014 1 2 -- 0.63 --15 1 4 -- 0.98 1.4516 2 1 -- 1.11 1.3017 2 2 -- 0.47 0.9618 2 4 0.63 0.79 1.3019 2 6 -- 1.14 1.5420 4 1 -- 1.22 1.7322 4 4 -- 0.73 1.19______________________________________
TABLE 4______________________________________Thermal Variation in Length: (%)Adjuvant (weight %) Mean grain size (μm)No. MgO SiO.sub.2 4.29 2.55 1.54______________________________________ 7 0 0 0.19 0.20 -- 9 0 2 -- 0.33 --12 2 0 -- 0.36 --13 1 1 -- -- 0.2614 1 2 -- 0.26 --15 1 4 -- 0.22 0.2816 2 1 -- 0.24 0.2717 2 2 -- 0.21 0.2518 2 4 0.19 0.17 0.2219 2 6 -- 0.20 0.2220 4 1 -- 0.22 0.2722 4 4 -- 0.22 0.29______________________________________
TABLE 5______________________________________Young' s Modulus: (×10.sup.3 kg/mm.sup.2)Adjuvant (wt. %) Mean grain size (μm)No. MgO SiO2 8.06 6.54 4.29 2.55 1.54______________________________________ 7 0 0 0.1 0.1 0.6 0.5 -- 8 0 1 0.3 0.3 0.6 1.0 -- 9 0 2 0.3 0.4 1.0 1.0 --10 0 4 0.3 0.5 1.0 1.5 --11 1 0 0.7 1.0 1.0 1.5 --12 2 0 0.9 1.1 1.3 1.8 --13 1 1 1.3 2.0 2.2 1.9 2.714 1 2 1.4 1.8 1.7 1.7 2.315 1 4 1.5 1.6 1.8 2.0 2.616 2 1 1.8 2.1 2.7 2.9 3.017 2 2 1.7 2.2 2.4 2.8 2.818 2 4 1.3 1.8 2.3 2.8 2.819 2 6 -- -- -- 2.5 3.020 4 1 -- -- -- 2.9 3.121 4 2 -- -- -- 2.6 3.022 4 4 -- -- -- 2.2 2.3______________________________________
As is clear from Table 2 and Table 5, the embodiments of this invention (sample numbers 13 to 22) showed high strength, high Young's Modulus and, in particular, those embodiments where the mean grain size of the aluminum titanate raw material was less than 7 microns showed superior strength and high Young's Modulus characteristics.
Also, as shown in Table 3 and Table 4, in the embodiments of this invention, the aluminum titanate had excellent low thermal expansion rate and small thermal variation in length characteristics. Thus, as described above, by means of this invention, aluminum titanate ceramic sintered bodies can be obtained that have a high strength and a small thermal variation in length when subjected to cyclic thermal treatment, without impairing the high melting point and low thermal expansion possessed by aluminum titanate.
The foregoing description and examples have been set forth merely to illustrate the invention and are not intended to be limiting. Since modifications of the described embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the scope of the invention should be limited solely with reference to the appended claims and equivalents. | A ceramic sintered body having a Young's Modulus of not less than 1,600 kg/mm 2 produced by sintering 1 to 10 weight % of magnesium oxide, 0.5 to 10 weight % of silicon oxide, the remainder being substantially aluminum titanate. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to a quiet cooling system for internal combustion engines which includes a radial fan and a ring radiator, the radiator being mounted at the circumference of a radial impeller at a distance from the latter. The invention relates, more particularly, to such a system in which the radiator is made integral or of radiator segments, the radiator including tubes conducting water, cooling fins being fastened to the tubes.
By the mid 1980's, the permissible noise level of motor vehicles equipped with internal combustion engines will be approximately 10 dB(A) below the values currently permitted. In addition to reducing noise emitted by the internal combustion engine and its components, the noise level produced by the cooling system associated with the internal combustion engine will also have to be decreased approximately 10 dB(A).
Numerous proposals have been made in attempts to achieve the noise reduction goal. The proposals, in most cases, provide for increasing the front surface of conventional, flat radiators. This is intended to result in a corresponding reduction of the pressure loss, so that circumferential velocity of the fan, which is especially critical for noise production, can be reduced.
Such cooling systems, however, require so much space that they cannot be accommodated in the engine compartments of motor vehicles. For this reason, some proposals provide for installation behind the cab of a vehicle or on the cab roof of the vehicle. Both designs have considerable disadvantages, namely, shortening of the truck floor and/or an unfavorable load on the cab, as well as an increase danger of scalding in the event of accidents.
Cooling systems with ring radiators and radial fans are also known. However, known designs suffer from numerous disadvantages.
Usually, radiators with radially disposed ribs are used, the ribs being aligned with circularly bent cooling tubes. This results in a considerable loss of thrust for the air, since the cooling air enters the radiator with a large circumferential component.
To avoid these thrust losses, several known designs bend the cooling ribs in such manner that their entrance angle corresponds to the influx angle, such as the respective radiators disclosed in British Pat. No. 153,175; and in German Federal Republic Pat. No. 1,576,705. Manufacturing cooling ribs shaped in this fashion, however, increases the cost of the radiator. It is also difficult to achieve the correct entrance angle, so that considerable thrust losses can still develop. Moreover, the influx angle of the cooling air varies with the operating state of the vehicle, so that a smooth design can be achieved only for a specific operating point, depending on the vehicle speed and/or the exit angle. In other known ring radiators, disk-shaped plates are used to guide the water using cooling ribs disposed between the plates and so as to be radial or inclined in the direction of the incoming flow of cooling air, such as disclosed in German Federal Republic Auslegeschrift (Published Patent Application) No. 1,551,519 and German Federal Republic Offenlegungsschrift (Laid Open Patent Application) No. 1,925,809.
However, the manufacture of these designs is still costly and radiators so constructed still suffer from high, undesirable thrust losses.
Ring radiators built up of segments are also known as rotating heat exchangers, whose tubes run parallel to the axis of rotation. In this manner, the rotating heat exchanger itself acts as a fan, for example, as disclosed in German Federal Republic Offenlegungsschrift (Laid Open Patent Application) No. 2,610,673.
In order to maintain the necessary cooling area, the radiator width of known systems is usually greater than the exit width of the radial fan (German Auslegeschrift No. 1,551,519, Supra; German Pat. No. 1,576,705, supra). In order to achieve an air distribution which is as uniform as possible over the entire width of the radiator, conical guide rings are disposed side by side between the fan and radiator, so that a plurality of diffusing rings forms a cross section which increases gradually from the impeller outlet width to the width of the radiator, for example, as disclosed in German Federal Republic Offenlegungsschrift (Laid Open Patent Application) No. 2,050,265. This measure also increases manufacturing costs, and results in an increase in the diameter of the cooling system.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a quiet cooling system which includes a ring radiator and a radial impeller which can simultaneously be made so compact that the system can be accommodated in the engine compartment of a vehicle.
It is another object of the present invention to provide a quiet cooling system which effects a largely smooth entry of the cooling air over the entire operating range, without resorting to guide rings and cooling ribs in the shape of guide plates.
It is a further object of the present invention to provide a quiet cooling system in which a more uniform load is imposed on the radiator with the smallest possible radiator diameter, so that a cooling assembly which is simple to manufacture can be used.
The foregoing objects, as well as others which are to become clear from the text below, are achieved according to the invention in a cooling system of the type described hereinabove essentially by virtue of the fact that the cooling water tubes are located parallel to the rotational axis of the impeller, the fins being located parallel to the flow direction of the cooling air leaving the radial impeller.
For the radial impeller to be provided with a rounded cover plate is particularly advantageous so that an inlet nozzle can project into this radial impeller. The inlet nozzle is desirably shaped so that the slot air entering between the radial impeller and the inlet nozzle and the main flow contain an outwardly directed component. The slot air is supplied tangentially or nearly tangetially to the rounded edge of the radial impeller cover plate.
The cooling system according to the invention is provided with a ring radiator with an arrangement of cooling water tubes and cooling ribs which favors flow, in conjunction with a relatively broad radial impeller and an especially shaped inlet nozzle.
Various possibilities can be employed for the structural design of a cooling system according to the invention.
According to one embodiment, it is advantageous for the inlet nozzle to be connected with a cover plate on the radial impeller and to turn with the latter.
According to another embodiment of the invention it is advantageous for the ratio of the impeller outlet surface to the narrowest cross section of the inlet nozzle to be greater than 1.2.
The cooling water tubes, provided with cooling fins, are disposed, for example, between two annular water jackets. It is particularly advantageous in this connection to make the ring radiator of individual cooling segments, these segments being disposed on the circumference of a frame, consisting of shaped, lightweight parts, and being arranged in the form of a ring or polygon at a distance from the circumference of the impeller. It has also been found advantageous to use a basket-like member as a support structure, on whose circumference individual cooling elements are mounted; the latter can also be made first, resulting in a polygon. However, it can also be made of lightweight shaped plates or cast parts. Other members can be used, for example heat exchangers for motor vehicle heaters, which are very economical to manufacture because of the large numbers in which they are produced.
A design which results in a heat exchanger is used for the ring radiator surrounding the radial impeller, with the cooling water being guided through tubes having a cross section that promotes the flow of the cooling air, for example, round tubes. The cooling water tubes run parallel to the fan axis. Cooling fins are mounted in rows on the cooling water tubes, the fins being located parallel to the flow direction of the cooling air leaving the radial impeller, so that, with the exception of the boundary zones, no inlet shock results when the direction of the inflowing air changes. In this manner, the pressure losses in the radiator are considerably reduced relative to known designs; this has a favorable effect both upon the power requirements of the fan and also the noise level.
The structure of the basket-like member, according to another embodiment of the invention, is constituted at least partially of hollow members in such manner that these hollow members serve as manifolds for the cooling water, supplying it and carrying it away, and thus constitute the water distribution system.
It is particularly advantageous if the individual radiator segments are connected directly together on the water jackets, and the water jackets form a water distributor channel.
Another advantage over known designs consists in a significant improvement in the manner in which air is fed to the radiator, without requiring costly and cumbersome guides. This is accomplished by using a relatively broad radial impeller in conjunction with a specially shaped inlet nozzle.
Some known ring radiator designs also have broad radial fans, as disclosed for example, in German Federal Republic Offenlegungsschrift (Laid Open Patent Application) No. 1,576,708. Such radiators are so designed that the impeller outlet cross section is greater than the cross section of the axial inlet opening. It has been found however that in such designs, without an inlet nozzle according to the present invention, the flow separates at the rounded edge of the impeller cover plate, so that only a portion of the total outlet width of the impeller has the cooling air flowing through it. As a result, the amount of air fed to the radiator is reduced and the efficiency of the air decreases and the noise level increases. For this reason, it has already been provided, to avoid separation of the flow, to accelerate the flow between the inlet and outlet cross sections of the impeller (German Pat. No. 1,576,705, supra). This results in narrow impellers and makes it necessary to use diffusers between the impeller and the radiator.
In annular cooling systems as are currently in use or have been described in the literature, inlet nozzles are sometimes provided (German OLS No. 2,050,265, supra). These nozzles are designed so that there is a good sealing effect between the nozzle and the impeller, in order to keep the slot losses as small as possible. The air slot is consequently as small as possible and usually is also made in the form of a labyrinth seal, which is very costly from the manufacturing standpoint. This slot design is conventional in the construction of pumps and compressors, but requires the use of narrow impellers, in which the flow cannot be retarded in the vicinity of a 90° deflection, or must even undergo acceleration in order to avoid separation at the impeller cover plate. In the case of a delayed flow, a broad, considerably braked boundary layer is produced at the rounded part of the cover plate, whose energy does not suffice to participate in the complete deflection in the radial direction.
In the proposed inlet nozzle, according to the present invention, in conjunction with a broad impeller, a relatively large air gap is provided without a labyrinth seal. The gap air, entering in the axial direction between the nozzle and the impeller cover plate, is supplied tangentially or nearly tangentially to the rounded part of the impeller cover plate. As a result, the slot air flow is drawn against the rounded part of the cover plate by the known Coanda effect, and undergoes a 90° deflection in the radial direction without separation. Simultaneously, the main flow receives an outwardly directed component within the inlet nozzle. The slot flow supplies so much energy to the boundary layer formed at the cover plate that the main flow, despite being delayed in the vicinity of the 90° deflection, is guided through the impeller without separation.
If the impeller mount is firmly connected to the ring radiator, the air gap between the impeller and the inlet nozzle mounted on the ring radiator can be 3 to 10 mm. Good fan efficiency is achieved even at the higher value. No particularly strict requirements are consequently imposed on manufacturing precision.
In other types of installations, the impeller is mounted on the crankshaft or water pump shaft of the internal combustion engine, while the radiator is mounted on the vehicle frame or body. If the inlet nozzle is mounted on the ring radiator, a large air gap, approximately 20 mm, must be provided in view of the relative movements which take place between the nozzle and the radial impeller. However, even with such a large air gap, good efficiency and air delivery are still achieved. The momentum of the powerful slot flow provides a separation-free deflection even with a considerable delay.
Another possibility resides in mounting the inlet nozzle on the engine block, with an elastic connection being provided between the nozzle and the ring radiator.
In conjunction with the proposed inlet nozzle, the main flow can be delayed so markedly in the vicinity of the 90° deflection that the impeller outlet cross section can be made much greater than the axial inlet cross section. However, this results in a much more fully loaded impeller outlet width in contrast to known ring radiator installations, resulting in a number of advantages and improvements, six of which are set out below.
Firstly, the ratio between the widths of the radiator and impeller is reduced, and the load imposed on the radiator is smoothed out as a result, thus increasing the cooling efficiency.
Secondly, the outlet velocity at the impeller is lower, so that the thrust loss caused by the sudden expansion of the cross section is reduced.
Thirdly, the small additional component of the air leaving the radial impeller results in a very flat exit angle, so that the helical path of the air between the impeller outlet and the radiator is increased over known designs, this enabling the air to be distributed better over the width of the radiator.
Fourthly, the considerable delay in the flow within the radial impeller is associated with a considerable static pressure value, so that the impeller can be operated at a relatively low circumferential velocity, and this in turn has a particularly favorable effect upon its noise behavior.
Fifthly, due to the small component of dynamic pressure, as a result of the delay in the impeller, the static efficiency is very high, so that a reduction of the power consumption over conventional cooling systems is likewise achieved.
Sixly, the low dynamic pressure and/or the low radiator inlet velocity likewise contribute to a reduction of the pressure loss and noise level.
Hence, the features of the present invention result in a decrease in radiator resistance over known ring radiator designs, a reduction of the radiator influx velocity, and an increase in the static pressure value of the radial impeller, so that a cooling system of this type operates very quietly, can be made compact and reasonably priced, and requires low operating power.
Experiments with a cooling system designed according to the present invention resulted in a decrease in the noise level by approximately 10 dB(A), occupying the same amount of space as conventional installations with a flat radiator and an axial fan. The radial fan was mounted so that the flow between the nozzle in the cross section and the impeller outlet surface was delayed by approximately one half. No flow separation was observed. The velocity distribution in the radiator was much more uniform than in installations which do not have the features according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages and features of the invention are described in greater detail hereinbelow with reference to the drawings, which show embodiments in diagramatic form.
FIG. 1 is a somewhat diagramatic, side view of a first embodiment of a cooling system according to the present invention having a ring radiator, radial fan and inlet nozzle;
FIG. 2 is a somewhat diagramatic, front view of the cooling system of FIG. 1;
FIG. 3 is a diagram of a velocity triangle at the impeller outlet, shown diagramatically, of the system of FIGS. 1 and 2;
FIG. 4 is a partial view of the inlet nozzle of the system of FIGS. 1 and 2 according to the present invention;
FIG. 5 illustrates an embodiment of a possible mount for a cooling system of the present invention; and
FIGS. 6 and 7 illustrate embodiments of the design of the ring radiator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the embodiment shown in FIG. 1 of a cooling system according to the present invention, a plurality of heat exchanger segments (elements) 1 is assembled to form a polygon or circle, and forms thus a ring radiator. A radial impeller 2 is disposed inside the ring radiator, the impeller 2 being driven by a crank-shaft or water pump shaft 3 of an internal combustion engine partially shown at 4. The radial impeller 2 can be mounted on a separate bearing, which is mounted on the internal combustion engine 4, or constitutes an integrated unit together with the ring radiator.
An air inlet nozzle 5 projects into the radial impeller 2, this nozzle being fastened to the end of the radiator; for example with bolts 6. In the embodiment shown, the heat exchanger segments 1 are connected to two hollow shaped tubes 11 and 12, which serve respectively as manifolds for the cooling water feed and exhaust and simultaneously as supporting and connecting elements.
The back of the ring radiator is sealed by a rear sealing plate 7. In the center of the sealing plate 7 is an opening 28 for the drive shaft 3 of the radial impeller 2. When the device is mounted separately from the internal combustion engine, this mount can be located on the rear sealing plate 7 and the drive shaft 3 can be connected to the drive shaft of internal combustion engine 4 by a conventional V-belt drive, conventional resilient shaft or an articulated shaft (not shown).
The heat exchanger segments 1 are provided laterally with water jackets 8, these jackets serving simultaneously as fastening and connecting members with the collecting tubes 11 and 12 via flanges 10.
The front view of the embodiment of a cooling system according to the invention of FIG. 1, as shown in FIG. 2 illustrates that the heat exchanger segments 1 form a polygon, according the one possible variant of this embodiment. A cooling water feed stub 13 and a cooling water exit stub 14 are connectable by hoses, not shown, to the liquid cooling jacket of internal combustion engine 4.
The heat exchanger segments 1 include, as shown particularly in FIG. 1, cooling water tubes 15, which run parallel to impeller axis 17 and upon which cooling fins 16 are arranged in rows in such manner that they are parallel to air flow 18 leaving the radial impeller 2. In the upper left part of FIG. 2, a cross section taken along section line A--B of FIG. 1 is shown, an arrangement of the cooling water tubes of one of the heat exchanger segments 1 being shown at the upper left. Here the tubes 15 are arranged in rows, one row of the tubes 15 being displaced relative to the adjacent row or rows. However, any other arrangement of the rows of tubes 15 and these tubes themselves, with respect to one another, is also possible. It is especially advantageous if the tubes 15 are designed so that they particularly favor flow of the cooling air, for example if they are round tubes.
In FIG. 3, a velocity triangle is shown at the impeller outlet. The air leaves the radial impeller 2 at a relative velocity w 2 , while the circumferential velocity of the fan is u 2 . From w 2 and u 2 one obtains the absolute velocity c 2 . Hence, the flow moves at a velocity c 2 at an angle α 2 to heat exchanger segments 1, shown at the upper left of FIG. 3, and enters these particular heat exchanger segments 1 at approximately this angle α 2 . Within the heat exchanger, the flow is deflected by the stagnating effect of cooling water tubes 15 and the friction between the fins 16. Flow studies have shown that the cooling air leaves the heat exchanger segments 1 approximately at right angles to the outlet surfaces. The flow path between the radial impeller outlet and the heat exchanger inlet corresponds to a logarithmic spiral. In FIG. 3, this path is shown by arrows 19. The smaller the meridional velocity c 2m at the impeller outlet, the flatter the spiral and the greater the increase in the path between the impeller outlet and the heat exchanger segments 1. This favors the spread of the flow from the impeller outlet over the width of the ring radiator.
In order to achieve a low maridional velocity, the radial impeller 2 is made as wide as possible, but only a separation-free flow in the impeller 2 is produced by the connection to the inlet nozzle 5.
The manner of operation of the inlet nozzle 5 is clearly evident from FIG. 4. At point 20, in other words in the air gap between the radial impeller 2 and the inlet nozzle 5, there is a slot air flow, which favors restriction of the main flow to the rounded part of an impeller cover plate 21, when the inlet nozzle 5 is shaped so that the slot air flow and the main flow contain an outwardly directed component and are supplied tangentially or nearly tangentially to the impeller cover plate 21.
In the case of the described and illustrated form of the nozzle 5, the slot air flow is attracted to the rounded part of the impeller cover plate 21 by the known Coanda effect, and adds so much energy to the main flow that excessive braking of the boundary layer at the rounded part of the cover plate is avoided and separation of the main flow is prevented. This effect makes possible a considerable delay in the deflected flow. As a result, the flow is also separation free, if the blade exit cross section F 2 is greater than 1.2 times the narrowest nozzle cross section F 0 , where F 2 =D 2 ×b 2 ×π (with b 2 equal to the blade width and D 2 equal to the blade outlet diameter). The considerable delay results in a low exit velocity and a high static pressure component, which is desirable for quiet operation and uniform loads upon the radiator.
With a greater relative motion between the radial impeller 2 and the ring radiator, for example if the radial impeller 2 is mounted on the drive shaft of the internal combustion engine 4 and the radiator, having the heat exchanger segments 1, is mounted on a vehicle frame 25, the inlet nozzle 5 can be fastened on the radial impeller 2 maintaining the relatively narrow air gap 20, as shown in FIG. 5. At point 22, a second air gap develops in the radial direction, through which cold air escapes. The slot air flow can be used to cool the collecting tubes 12.
The inlet nozzle 5, which turns with the fan, is connected by projections 23 to the inside of the impeller cover plate 21.
There are other possibilities for the structural design of the ring radiator besides those shown in the embodiment in FIG. 1. In FIGS. 6 and 7, the water jackets 8 themselves form the collecting channels or tubes 11 and 12 and serve simultaneously as connecting members to the adjacent heat exchanger segments 1, in which the water jackets are provided laterally with connecting flanges 24. The mounting of the ring radiator on the vehicle frame 25 is shown, by way of example in FIG. 2, brackets 26 being used for fastening and vibration dampers 27 being provided between these brackets and the vehicle frame 25.
Another possibility for mounting the radiator resides in the fact that the latter can be connected to internal combustion engine 4. In this case, the air gap between the radial impeller 2 and the inlet nozzle 5, which is integral with the radiator, can be kept relatively small, resulting in small slot losses; in other words a good fan efficienty results.
The spirit and scope of the invention is not limited to the embodiments and variants shown in the accompanying drawings and described hereinabove. It is also includes all possible embodiments and variants, as well as partial and subcombinations of the features and measures described and/or shown, its scope being defined in the appended claims. | A quiet cooling system for internal combustion engines includes a radial impeller and a ring radiator. The ring radiator is disposed in the vicinity of the circumference of the radial impeller and is spaced at a distance from the impeller. The ring radiator can be made integral or in the form of segments. The radiator includes cooling water tubes which are to carry water and have fins fastened thereto. The cooling water tubes run parallel to the fan axis and are positioned parallel to the flow direction of cooling air leaving the radial impeller. | 5 |
BACKGROUND
[0001] 1. Technical Field
[0002] This invention relates generally to communication systems and, more particularly, to integrated time references within a device for use either as a clock reference or calibration master within portable electronics including radio frequency (RF) wireless devices operating in wireless communication systems.
[0003] 2. Related Art
[0004] Communication systems are known to support wireless and wire lined communications between wireless and/or wired communication devices. Such communication systems range from national and/or international cellular telephone systems to the Internet to point-to-point in-home wireless networks. Each type of communication system is constructed, and hence operates, in accordance with one or more communication standards. For instance, wireless communication systems may operate in accordance with one or more standards including, but not limited to, IEEE 802.11, Bluetooth, advanced mobile phone services (AMPS), digital AMPS, global system for mobile communications (GSM), code division multiple access (CDMA), wireless application protocol (WAP), local multi-point distribution systems (LMDS), multi-channel-multi-point distribution systems (MMDS), and/or variations thereof.
[0005] Depending on the type of wireless communication system, a wireless communication device, such as a cellular telephone, two-way radio, personal digital assistant (PDA), personal computer (PC), laptop computer, home entertainment equipment, etc., communicates directly or indirectly with other wireless communication devices. For direct communications (also known as point-to-point communications), the participating wireless communication devices tune their receivers and transmitters to the same channel of the other parties (e.g., one of the plurality of radio frequency (RF) carriers of the wireless communication system) and exchange information over that channel. For indirect wireless communications, each wireless communication device communicates directly with an associated base station (e.g., for cellular services) and/or an associated access point (e.g., for an in-home or in-building wireless network) via an assigned channel. To complete a communication connection between the wireless communication devices, the associated base stations and/or associated access points communicate with each other directly, via a system controller, via the public switched (PSTN) telephone network, via the Internet, and/or via some other wire lined or wireless network.
[0006] Each wireless communication device includes a built-in radio transceiver (i.e., receiver and transmitter) or is coupled to an associated radio transceiver (e.g., a station for in-home and/or in-building wireless communication networks, RF modem, etc.) to participate in wireless communications. As is known, the receiver receives RF signals, removes the RF carrier frequency from the RF signals via one or more intermediate frequency stages, and demodulates the signals in accordance with a particular wireless communication standard to recapture the transmitted data. The transmitter converts data into RF signals by modulating the data in accordance with the particular wireless communication standard and adds an RF carrier to the modulated data in one or more intermediate frequency stages to produce the RF signals.
[0007] As is also known, the receiver is coupled to the antenna and includes a low noise amplifier (LNA), zero or more intermediate frequency (IF) stages, a filtering stage, and a data recovery stage in many designs. The low noise amplifier receives an inbound RF signal via the antenna and amplifies it. The down converters mix the amplified RF signal with one or more local oscillations to convert the amplified RF signal into a baseband signal or an intermediate frequency signal. As used herein, the term “low IF” refers to both baseband and low intermediate frequency signals. A filtering stage filters the low IF signals to attenuate unwanted out of band signals to produce a filtered signal. The data recovery stage recovers raw data from the filtered signal in accordance with the particular wireless communication standard.
[0008] As the demand for enhanced performance (e.g., reduced interference and/or noise, improved quality of service, compliance with multiple standards, increased broadband applications, etc.), smaller sizes, lower power consumption, and reduced cost continue to be asserted, wireless communication device engineers are faced with a very difficult design challenge to develop a wireless communication device that satisfies requirements that sometimes appear to be mutually exclusive.
[0009] Integrated time references are used for many purposes, including synchronization of internal operations, synchronization with buses and external networks, among other applications. For example, for a device that communicates over an external synchronized bus, it is important that the device has an internal time reference that it can use to detect and respond to the signals on the bus. Generally, synchronized buses require that all operations happen at specified instants in time. Thus, a device must not only be able to read the synchronized signals being received on the bus, but must also be able to transmit at specified instants in a synchronized manner.
[0010] Crystal oscillators have long been used to provide very accurate time keeping functions as a result of their steady and predictable response to physical or electrical stimuli. Integrated circuits, however, by their very nature, cannot incorporate an internal crystal oscillator. Accurate internal time keeping is needed, for example, by analog-to-digital converter (ADC) circuits. ADCs are complex analog-to-digital converters that are often used to digitize analog wave forms, for example, voice wave forms, as a part of converting a voice signal to a digital signal that may be manipulated, stored or transmitted over a wireless medium. Other circuits that require accurate time keeping are the frequency generation circuits, such as phase-locked loops, so that ingoing and outgoing communication signals may readily be exchanged with other devices.
[0011] More specifically, the conversion of the voice signal from analog to digital will be most accurate and most reproducible if the sampling occurs at precise and constant measures of time. A transmitter must be able to accurately drive a signal on a synchronized bus. Thus, for these and many other reasons, a need exists not only for internal time sources that may be used as a reference signal, but also for accuracy. At the same time, however, there is the ever increasing need or desire to reduce power consumption in electronic circuits, especially for portable devices, to conserve battery life. Because of the desire to reduce power consumption, especially for portable devices, it is customary for a transceiver to operate in a sleep mode during periods of inactivity and in a normal mode while processing data. The sleep mode is provided to avoid wasting power when data is not being transmitted, received or processed. When a device is to end a sleep mode, it must periodically wake-up and attempt to establish a connection with nearby devices. The timing for waking up is required to be reasonably accurate, nonetheless. Additionally, when the device wakes up, it must be able to lock with a specified clock or with a received RF signal in order to accurately process data. Thus, most current designs include clock systems that consume sufficient power to provide accurate time keeping. Known designs that reduce power consumption during a sleep mode often fail to provide the desired accuracy. What is needed, therefore, is a system that maintains adequate clock timing while reducing power consumption.
SUMMARY OF THE INVENTION
[0012] In one embodiment of the present invention, two crystal oscillator circuits are coupled in parallel to provide differing performance according to mode. Generally, a first circuit provides low phase noise and high accuracy while a second circuit provides greater phase noise within an acceptable tolerance while consuming significantly less power in a low power mode of operation. The second circuit includes an separate amplifier for the low power operation that tolerates a relatively smaller input signal swing but that consumes even less power. The first circuit, which comprises selectable amplification elements, and the second circuit are coupled in parallel with selectable resistive elements and capacitive elements to provide varying amounts of amplification and filtering according to whether an operational mode is in startup mode, a normal mode, or a low power mode of operation.
[0013] A method of operation according to one embodiment of the present invention includes operating differing circuit configurations according to whether the device is in a startup mode, a normal mode, or a low power mode. In a startup mode, amplification is maximized and resistance and capacitance are minimized for the multi-mode oscillator. In a normal mode, amplification is optimized for performance, resistance is maximized, and the capacitance is tuned to correspond with a crystal frequency. In a low power mode, amplification is minimized so long as an oscillation is maintained, resistance is maximized, and capacitance is minimized or removed.
[0014] As one aspect of the embodiment of the invention, a plurality of amplifiers are provided wherein a first amplifier is operably selected for the startup and normal mode of operation and further wherein a second amplifier is operably selected for the low power mode of operation. More specifically, the second amplifier is a differential amplifier that receives a signal having a small signal swing and produces an output signal consuming less power than the first amplifier.
[0015] As will be described in greater detail below, a crystal oscillator is coupled to the first amplifier having an adjustable amplification block. Accordingly, the gain level of the first amplifier may be adjusted according to desired operation. Similarly, across the input and output nodes, a plurality of parallel coupled resistors are coupled to provide adjustable resistance levels in conjunction with a plurality of parallel coupled capacitors that are also selectable and are coupled across the input and output nodes of the first and second amplifiers. Accordingly, the adjustable resistance block with selectable resistors, in addition to a pair of the adjustable capacitive blocks with selectable capacitors, facilitate adjustment of the operation of the multi-mode crystal oscillator. In the specific embodiments of the invention, MOSFET devices are used as switches to operatively couple or decouple the resistors and capacitors of the adjustable resistance block and the adjustable capacitive blocks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic block diagram illustrating a communication system that includes a plurality of base stations and access points, a plurality of wireless communication devices and a network hardware component according to one embodiment of the present invention;
[0017] FIG. 2 is a schematic block diagram illustrating a wireless communication device that includes the host device and an associated radio;
[0018] FIG. 3 is a functional block diagram of a dual mode crystal oscillator formed according to one embodiment of the present invention;
[0019] FIG. 4 is a functional block diagram of a multi-mode crystal oscillator formed according to one embodiment of the present invention;
[0020] FIG. 5 is a functional block diagram of a multi-mode crystal oscillator according to one embodiment of the present invention;
[0021] FIG. 6 is a functional block diagram of a multi-mode crystal oscillator according to one embodiment of the present invention; and
[0022] FIG. 7 is a flowchart that illustrates operation according to one embodiment of the present invention.
DETAILED DESCRIPTION
[0023] FIG. 1 is a schematic block diagram illustrating a communication system 10 that includes a plurality of base stations and access points 12 - 16 , a plurality of wireless communication devices 18 - 32 and a network hardware component 34 . Any one of the wireless communication devices may include an integrated temperature sensor formed according to an embodiment of the invention. The wireless plurality of communication devices 18 - 32 may be laptop host computers 18 and 26 , personal digital assistant hosts 20 and 30 , personal computer hosts 24 and 32 and/or cellular telephone hosts 22 and 28 . The details of the wireless communication devices will be described in greater detail with reference to FIG. 2 .
[0024] The base stations or access points 12 - 16 are operably coupled to the network hardware component 34 via local area network (LAN) connections 36 , 38 and 40 . The network hardware component 34 , which may be a router, switch, bridge, modem, system controller, etc., provides a wide area network (WAN) connection 42 for the communication system 10 . Each of the plurality of base stations or access points 12 - 16 has an associated antenna or antenna array to communicate with the wireless communication devices in its area. Typically, the wireless communication devices register with a particular base station or access points 12 - 16 to receive services from the communication system 10 . For direct connections (i.e., point-to-point communications), wireless communication devices communicate directly via an allocated channel.
[0025] Typically, base stations are used for cellular telephone systems and like-type systems, while access points are used for in-home or in-building wireless networks. Regardless of the particular type of communication system, each wireless communication device includes a built-in radio and/or is coupled to a radio. The radio may include a highly linear amplifier and/or programmable multi-stage amplifier as disclosed herein to enhance performance, reduce costs, reduce size, and/or enhance broadband applications. As such, anyone of the devices of FIG. 1 , and especially the portable devices, may be formed to include any one of the embodiments of the invention.
[0026] FIG. 2 is a schematic block diagram illustrating a wireless communication device that includes the host device 18 - 32 and an associated radio 60 . For cellular telephone hosts, the radio 60 is a built-in component. For personal digital assistants hosts, laptop hosts, and/or personal computer hosts, the radio 60 may be built-in or an externally coupled component.
[0027] As illustrated, the host device 18 - 32 includes a processing module 50 , memory 52 , radio interface 54 , input interface 58 and output interface 56 . The processing module 50 and memory 52 execute the corresponding instructions that are typically done by the host device 18 - 32 . For example, for a cellular telephone host device, the processing module 50 performs the corresponding communication functions in accordance with a particular cellular telephone standard.
[0028] The radio interface 54 allows data to be received from and sent to the radio 60 . For data received from the radio 60 (e.g., inbound data), the radio interface 54 provides the data to the processing module 50 for further processing and/or routing to the output interface 56 . The output interface 56 provides connectivity to an output display device such as a display, monitor, speakers, etc., such that the received data may be displayed. The radio interface 54 also provides data from the processing module 50 to the radio 60 . The processing module 50 may receive the outbound data from an input device such as a keyboard, keypad, microphone, etc., via the input interface 58 or generate the data itself For data received via the input interface 58 , the processing module 50 may perform a corresponding host function on the data and/or route it to the radio 60 via the radio interface 54 .
[0029] Radio 60 includes a host interface 62 , a digital receiver processing module 64 , an analog-to-digital converter 66 , a filtering/gain module 68 , a down-conversion module 70 , a receiver filter module 71 , a low noise amplifier 72 , a transceiver/receiver module 73 , a local oscillation module 74 , memory 75 , a digital transmitter processing module 76 , a digital-to-analog converter 78 , a filtering/gain module 80 , an up-conversion module 82 , a power amplifier 84 , a transceiver filter module 85 , and an antenna 86 . The antenna 86 may be a single antenna that is shared by the transmit and receive paths as regulated by the transceiver/receiver module 73 , or may include separate antennas for the transmit path and receive path. The antenna implementation will depend on the particular standard to which the wireless communication device is compliant.
[0030] The digital receiver processing module 64 and the digital transmitter processing module 76 , in combination with operational instructions stored in memory 75 , execute digital receiver functions and digital transceiver functions, respectively. The digital receiver functions include, but are not limited to, digital intermediate frequency to baseband conversion, demodulation, constellation demapping, decoding, and/or descrambling. The digital transceiver functions include, but are not limited to, scrambling, encoding, constellation mapping, modulation, and/or digital baseband to IF conversion. The digital receiver and transmitter processing modules 64 and 76 may be implemented using a shared processing device, individual processing devices, or a plurality of processing devices. Such a processing device may be a microprocessor, micro-controller, digital signal processor, microcomputer, central processing unit, field programmable gate array (FPGA), programmable logic device, state machine, logic circuitry, analog circuitry, digital circuitry, and/or any device that manipulates signals (analog and/or digital) based on operational instructions. The memory 75 may be a single memory device or a plurality of memory devices. Such a memory device may be a read-only memory (ROM), random access memory (RAM), volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, and/or any device that stores digital information. Note that when the digital receiver processing module 64 and/or the digital transmitter processing module 76 implements one or more of its functions via a state machine, analog circuitry, digital circuitry, and/or logic circuitry, the memory storing the corresponding operational instructions is embedded with the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry. The memory 75 stores, and the digital receiver processing module 64 and/or the digital transmitter processing module 76 executes, operational instructions corresponding to at least some of the functions illustrated in FIGS. 3 , et. seq. Within the blocks of FIG. 2 , the embodiments of the invention may be used to provide required timing and clock signals to blocks such as the DAC and ADC blocks, the local oscillation module and the processor module among others.
[0031] In operation, the radio 60 receives outbound data 94 from the host device via the host interface 62 . The host interface 62 routes the outbound data 94 to the digital transmitter processing module 76 , which processes the outbound data 94 in accordance with a particular wireless communication standard (e.g., IEEE 802.11a, IEEE 802.11b, Bluetooth, etc.) to produce digital transmission formatted data 96 . The digital transmission formatted data 96 will be a digital baseband signal or a digital low IF signal, where the low IF signal typically will be in the frequency range of one hundred kilohertz to a few megahertz.
[0032] The digital-to-analog converter 78 converts the digital transmission formatted data 96 from the digital domain to the analog domain. The filtering/gain module 80 filters and/or adjusts the gain of the analog signal prior to providing it to the up-conversion module 82 . The up-conversion module 82 directly converts the analog baseband or low IF signal into an RF signal based on a transceiver local oscillation 83 provided by local oscillation module 74 . The power amplifier 84 amplifies the RF signal to produce outbound RF signal 98 , which is filtered by the transceiver filter module 85 . The antenna 86 transmits the outbound RF signal 98 to a targeted device, such as a base station, an access point and/or another wireless communication device.
[0033] The radio 60 also receives an inbound RF signal 88 via the antenna 86 , which was transmitted by a base station, an access point, or another wireless communication device. The antenna 86 provides the inbound RF signal 88 to the receiver filter module 71 via the transceiver/receiver module 73 , where the receiver filter module 71 bandpass filters the inbound RF signal 88 . The receiver filter module 71 provides the filtered RF signal to low noise amplifier 72 , which amplifies inbound RF signal 88 to produce an amplified inbound RF signal. The low noise amplifier 72 provides the amplified inbound RF signal to the down-conversion module 70 , which directly converts the amplified inbound RF signal into an inbound low IF signal or baseband signal based on a receiver local oscillation 81 provided by local oscillation module 74 . The down-conversion module 70 provides the inbound low IF signal or baseband signal to the filtering/gain module 68 . The filtering/gain module 68 may be implemented in accordance with the teachings of the present invention to filter and/or attenuate the inbound low IF signal or the inbound baseband signal to produce a filtered inbound signal.
[0034] The analog-to-digital converter 66 converts the filtered inbound signal from the analog domain to the digital domain to produce digital reception formatted data 90 . The digital receiver processing module 64 decodes, descrambles, demaps, and/or demodulates the digital reception formatted data 90 to recapture inbound data 92 in accordance with the particular wireless communication standard being implemented by radio 60 . The host interface 62 provides the recaptured inbound data 92 to the host device 18 - 32 via the radio interface 54 .
[0035] As one skilled in the art will appreciate, the wireless communication device of FIG. 2 may be implemented using one or more integrated circuits. For example, the host device may be implemented on one integrated circuit, the digital receiver processing module 64 , the digital transmitter processing module 76 and memory 75 may be implemented on a second integrated circuit, and the remaining components of the radio 60 , less the antenna 86 , may be implemented on a third integrated circuit. As an alternate example, the radio 60 may be implemented on a single integrated circuit. As yet another example, the processing module 50 of the host device 18 - 32 and the digital receiver and transmitter processing modules 64 and 76 may be a common processing device implemented on a single integrated circuit. Further, the memory 52 and memory 75 may be implemented on a single integrated circuit and/or on the same integrated circuit as the common processing modules of processing module 50 and the digital receiver and transmitter processing modules 64 and 76 .
[0036] FIG. 3 is a functional block diagram of a dual mode crystal oscillator formed according to one embodiment of the present invention. As may be seen, an oscillator block 102 further includes a crystal 104 that is coupled to a parallel with a normal/startup mode block 106 and a low power mode block 108 . Generally, only one of block 106 and block 108 is operably coupled to produce clock signals that are converted to a square wave clock signal by a squaring block. Block selection logic 110 produces mode block select signals to operatively couple one of blocks 106 and 108 .
[0037] Mode block 106 generally produces an output signal that includes less phase error. One cost of this benefit, however, is that mode block 106 consumes more power than low power mode block 108 . Because mode block 106 requires a signal having greater signal gain, the output signal is produced to a squaring block 112 A having a plurality of inverters that operate to generate a square wave clock signal without requiring additional amplification. The output of low power mode block 108 , however, produces an output signal that requires additional amplification. Accordingly, the output of low power mode block 108 is produced initially to an amplifier 114 prior to being produced to a squaring block 112 B containing a plurality of inverters to produce a square wave clock signal. The outputs of each of the squaring blocks 112 A and 112 B are then produced to a multiplexer 116 which selects an output signal to produce the square wave caught based upon a clock select signal generated by block selection logic 110 .
[0038] In operation, oscillator block 102 , and more specifically, block selection logic 110 , selects mode block 106 during startup and normal modes of operation and further selects low power mode block 108 only during a low power mode of operation, such as a sleep mode.
[0039] FIG. 4 is a functional block diagram of a multi-mode crystal oscillator formed according to one embodiment of the present invention. As may be seen, a crystal 120 is coupled in parallel with a variable amplifier 122 and with a variable resistor 124 . Between an input side of the variable amplifier 122 and circuit common is a variable capacitor 126 . Similarly, between an output side of the variable amplifier 122 and circuit common is a variable capacitor 128 . Generally, the values of resistor 124 , capacitor 126 , and capacitor 128 , as well as the gain level settings of variable amplifier 122 , are set according to whether the multi-mode crystal oscillator is in a startup mode, a normal mode, or a low power mode of operation. More specifically, in a startup mode, the variable amplifier 122 is set to maximize the gain level setting while the resistive and capacitive values are minimized. In a normal mode of operation, the gain level settings of variable amplifier 122 are optimized for performance considering factors such as power consumption, flicker noise, and output gain, the resistive value is maximized, and the capacitive value is tuned for the crystal frequency. One of average skill in the art may readily determine acceptable values therefor. Finally, in a low power mode of operation, the capacitors are turned off, or, alternatively, minimized, while the resistive values are maximized and the gain level settings of the variable amplifier 122 are minimized to the level for which oscillation may be maintained.
[0040] To achieve some of these settings, one approach that may be employed is to selectively vary the gain level settings, the resistive values, and the capacitive values in a test mode with a test chip wherein the determined optimal (or acceptable) settings are selected for production chips. Because the integrated circuits are formed with selectable components that may be selected by firmware or, more generally, in production, the chips may be programmed in production to have the determined values for gain, resistance and capacitance in response to the various modes of operation as determine through test of the test chips.
[0041] FIG. 5 is a functional block diagram of a multi-mode crystal oscillator according to one embodiment of the present invention. In relation to the multi-mode crystal oscillator of FIG. 4 , crystal 120 and resistor 124 are coupled in parallel with a pair of selectable amplifiers. More specifically, a variable gain of an amplifier 132 is coupled in series with a switch 134 . In the described embodiment of the invention, switch 134 comprises a MOSFET switch that closes a circuit connection based upon a bias signal across a gate of the MOSFET switch 134 . Similarly, an amplifier 136 is coupled in series with a MOSFET switch 138 . Switches 134 and 138 are coupled to receive logically opposite bias signals so that only one of amplifiers 132 and 136 are operatively coupled across crystal 120 to produce an oscillation in conjunction with resistor 124 , capacitor 126 and capacitor 128 in the described embodiment.
[0042] In operation, switch 138 remains open and switch 134 remains closed thereby operatively coupling amplifier 132 and operatively decoupling amplifier 136 during the startup and normal mode of operation. Alternatively, switch 138 is closed and switch 134 is open to operatively decouple amplifier 132 and operatively couple amplifier 136 during a low power mode of operation. Generally, amplifier 132 consumes more power than amplifier 136 but produces an output signal that requires no additional amplification as a part of forming a square wave clock signal. Amplifier 132 is formed to receive an input signal having a substantially greater peak to peak value relative to an input signal for amplifier 136 . As such, amplifier 132 produces a cleaner signal at a cost of consuming greater power. Because amplifier 136 is formed to receive an input signal having a substantially lower peak to peak value, the output of amplifier 136 requires additional amplification thereby introducing some phase noise or other types of noise. While such operation is more noisy, including, for example, greater phase noise than is produced by amplifier 132 , the result of using amplifier 136 in conjunction with another amplifier produces an oscillation over an extended period of time that is substantially more accurate than non-crystal based oscillators and is not subject to frequency drift. Over time, any phase error averages out thereby producing a substantially accurate clock or timing signal.
[0043] FIG. 6 is a functional block diagram of a multi-mode crystal oscillator according to one embodiment of the present invention. A multi-mode oscillator 150 includes an adjustable amplification block 152 , an adjustable resistance block 154 , adjustable capacitive blocks 156 and 158 , and a low power mode amplification block 160 . Additionally, a switch logic block 162 generates bias signals to open and close MOSFET switches within blocks 152 - 160 according to operational mode. Adjustable amplification block 152 comprises a plurality of columns of MOSFET transistors that are each coupled in a series with a MOSFET switch.
[0044] In one embodiment of the invention, a first column of transistors is characterized by MOSFET transistors having a 12-to-1 length-to-width ratio. A second column of transistors is characterized by MOSFET transistors having a 12-to-4 length-to-width ratio. Generally, increasing a transistor area by a factor of four reduces flicker noise by a factor of two. Increasing a transistor's length by a factor of four typically reduces the current by a factor of two. Overall, changing transistor dimensions as described reduces gain approximately by a factor of four. Thus, increasing transistor dimensions lowers flicker noise and power consumed at a cost of decreased gain.
[0045] As described above, it is typically optimal to maximize gain in a startup mode of operation. In a normal mode of operation, however, gain is optimized for performance. Thus, if the plurality of columns of transistors of the variable gain amplifier are formed, as they are in the described embodiment of the invention, to have different dimensions and a corresponding gain level and flicker noise, performance of the multi-mode oscillator may be optimized. The above described ratios for the transistors are exemplary and may readily be modified as necessary for a particular application. Such modifications are considered to be within the scope of the invention.
[0046] Generally, switch logic block 162 generates control commands to operatively couple any one of transistors 164 by operatively biasing its corresponding switch 166 . Within adjustable resistance block 154 , any one of a plurality of resistors 168 may be operatively coupled into connection by its corresponding series coupled MOSFET switch 170 with an appropriate bias signal. Similarly, capacitors 172 of adjustable capacitive blocks 158 and 156 may be operatively coupled into connection by providing a bias signal to MOSFET transistors 174 .
[0047] As may also be seen, low power mode amplification block 160 is coupled in parallel with adjustable amplification block 152 which is further coupled in parallel with a crystal 176 . Low power mode amplification block 160 further includes a pair of MOSFET switches 178 that may be bias to operatively couple a differential amplifier formed by a pair of MOSFETs 180 . As may be seen, the source terminals of MOSFETs 180 are commonly coupled to a current sink 182 that provides a bias current therefor. As may also be seen, a capacitor 184 is coupled across the source terminals of MOSFETs 180 for filtration purposes among others. Additionally, a pair of load blocks 186 are coupled between supply and amplification blocks 160 and 152 . In the embodiment shown, each load block includes a MOSFET switch 188 and a load resistor R L . In an alternate embodiment, each of the load blocks 186 is replaced by a current source 190 . In a high power mode of operation, switches 188 are biased off to decouple the load resistors R L . In the alternate embodiment utilizing current sources 190 in place of the load resistors R L. , the current sources are turned off. Supply is still coupled at other locations within the circuit. Thus, the crystal 176 and supply remain operatively coupled even with the loads removed in the high power modes of operation. Finally, it should be noted that crystal 176 as shown is coupled across low power amplification block 160 as well as adjustable amplification block 152 .
[0048] In operation, when a device that includes multi-mode oscillator 150 is in a startup mode of operation, gain level settings are maximized. Accordingly, switch logic block 162 generates bias signals to each of the MOSFET switches 166 to close the connection and to operatively couple MOSFET transistors 164 to produce maximum gain level settings. Similarly, according to the teachings of the present embodiments of the invention, it is desirable to minimize the resistive value of the adjustable resistance block 154 . Accordingly, switch logic block 162 generates bias signals to operatively bias MOSFET switches 170 to operatively couple each of the resistors 168 to minimize resistance and capacitor rise time. As is known by one of average skill in the art, coupling resistors in parallel reduces overall resistance and therefore minimizes the resistive value of adjustable resistance block 154 . Similarly, because it is desirable to minimize capacitance according to the described embodiment of the present invention, and because coupling capacitors in parallel serves to increase overall capacitance, one of or even no capacitors 172 are operatively coupled by corresponding MOSFET transistors 174 in the startup mode. Thus, switch logic block 162 either generates no bias signals to transistors 174 or, alternatively, only operatively bias one transistor 174 for each of the adjustable capacitive blocks 156 and 158 . To keep FIG. 6 from becoming overly crowded with information, the bias signals as generated by switch logic block 162 and as received by each of the MOSFET switches at the gate terminal, are not shown, though such coupling and operation should be understood to exist. After an initial period in which all three resistors 168 are operatively coupled, one or more resistors are decoupled to increase resistance and gain of the amplifier. Improving the gain further improves the quality of the resonator. One of average skill in the art may readily determine the specific resistance values and associated timing therefor in order to satisfy specific circuit design and performance requirements.
[0049] When the multi-mode oscillator 150 is in a normal mode of operation, gain level settings are optimized for performance. In this embodiment, not all MOSFET transistors 164 of adjustable amplification block 152 are operatively coupled to provide amplification. Generally, it is desirable to increase transistor area to reduce flicker noise and to reduce required current levels while providing adequate gain. For example, in one embodiment of the present invention, the first column of transistors having a 12-to-1 length-to-width ratio may be operatively decoupled, while the second column of transistors having a 12-to-4 length-to-width ratio may be operatively coupled. For exemplary purposes, such a coupling may reduce power used by a factor of two, may reduce flicker noise by a factor of two, or may also reduce the output gain by a factor of four. If such performance in terms of gain is acceptable, then the battery life of the portable device is increased while oscillator performance is improved.
[0050] When the mode of operation transitions to a low power mode of operation, for example, during a sleep mode, the first and second rows of transistors of adjustable amplification block 152 are turned off. Additionally, the resistance value of adjustable resistance block 154 is maximized by decoupled two of the resistors 168 and the capacitive value adjustable capacitive block is minimized by coupling either no or a minimal number of capacitors as described before.
[0051] FIG. 7 is a flowchart that illustrates operation according to one embodiment of the present invention. In a startup mode of operation, the inventive method includes maximizing amplification, and minimizing resistance and capacitance (step 200 ). As a device transitions into a normal mode of operation, the inventive method includes optimizing amplification for performance, maximizing resistance and tuning capacitance for the crystal frequency (step 202 ). When the device transitions into a low power mode, for example into a sleep mode, the method includes minimizing amplification while maintaining oscillation, maximizing resistance, and turning off capacitance by decoupling capacitors (step 204 ). In one embodiment of the present invention, the method includes, while in a low power mode, turning off a first amplifier and turning on a selectable differential amplifier (step 206 ). Finally, while operating in a low power mode of operation, the invention includes, after a specified number of clock cycles, determining whether to transition to a normal mode to process, transmit, or receive data (step 208 ). Generally, a device might transition from a low power mode to a normal mode after about 30 seconds to determine whether there is data that needs to be processed, transmitted, or received. Once such data processing is complete, the device may transition back into a low power mode of operation. Thus, one benefit of the embodiment of the invention is realized. Accurate low power time keeping for a period in the range of 30 seconds or greater may be achieved.
[0052] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and detailed description. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but, on the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the claims. As may be seen, the described embodiments may be modified in many different ways without departing from the scope or teachings of the invention. For example, references to operation of a digital signal processor also may apply to baseband processors and vice-versa. Similarly, any combination of the teachings herein may be modified to achieve similar but different results. | In one embodiment of the present invention, two crystal oscillator circuits are coupled in parallel to provide differing performance according to mode. Generally, a first circuit provides low phase noise and high accuracy while a second circuit provides greater phase noise within an acceptable tolerance while consuming significantly less power in a low power mode of operation. The second circuit includes an entirely separate amplifier for the low power operation that tolerates a relatively smaller input signal swing but that consumes even less power. The first circuit, which comprises selectable amplification elements, and the second circuit are coupled in parallel with selectable resistive elements and capacitive elements to provide varying amounts of amplification and filtering according to whether an operational mode is in a startup mode, a normal mode, or a low power mode of operation. | 8 |
RELATED APPLICATION
This application is a continuation of application Ser. No. 10/365,822, filed on Feb. 13, 2003, now abandoned, which is a continuation-in-part of application Ser. No. 10/164,487, filed Jun. 6, 2002, now abandoned. The foregoing applications are hereby incorporated by reference herein in their entirety, including the specification, claims, drawings and abstract.
BACKGROUND OF THE INVENTION
The present invention relates to surgical apparatus for retracting a patient's anatomy during an operation to provide exposure of the operative site. More particularly, the present invention relates to a universal scissors joint apparatus that is sturdy, stable, readily adjustable, and easily sterilized.
Surgical operations often require prolonged access to the internal anatomy of a patient. Retractors are used to hold back tissue around the surgical site, granting the surgeon the needed access. While hand-held retractors may be used during surgeries, it is often desirable to use mechanically mounted retractors.
Mechanical retractors are typically mounted to some kind of support structure. This support structure often takes the form of a frame surrounding part or all of the operating table. The frame may contain rails to which clamps may be attached. These clamps may connect the frame directly to a retractor, or to accessory rails to which retractors or additional rails may be connected. Greater flexibility in universal joint clamps alleviates some of the deficiencies of previous rail clamps in comparison to the manual application of retractors.
Universal joints must be sterilized before being brought into the operating area. Many previous universal joints have separable components which require more care and effort for sterilization due to the need to disassemble and reassemble the components. Universal joints with unitary designs permit sterilization without the need to disassemble the joints.
Some previous universal joints have used threaded locking mechanisms, which require lubrication and maintenance. Cam locking mechanisms require less maintenance and provide a much easier and more effective system for locking and unlocking the clamps.
Cam locking universal joints typically incorporate a cam handle to open and lock the universal joint's locking mechanism. Unfortunately, the manipulation of the cam locking mechanism often results in the cam handle being oriented towards, and into, the operative site, thereby potentially interfering with a surgeon's visual access to the patient's anatomy or physically intruding with a surgeon's movement. For example, U.S. Pat. No. 5,888,197 (“'197”), and U.S. Pat. No. 6,017,008 (“008”) disclose floating cam handles that allow for the positioning of the cam handle at various orientations about the operative site and in relation to other support structure components. However, this freedom of movement may create unnecessary obstacles for the surgeon or create an additional issue that a surgical staff must consider and address. More specifically, in preparing for an operation, or while making adjustments during surgery, the fact that a cam handle was positioned into the field of operation, or at some other physically intrusive position, may be overlooked and impracticable to rectify.
U.S. Pat. No. 5,727,899 (“'899”) teaches a unitary universal joint, wherein the cam handle may be substantially parallel to the handle of a retractor blade. However, because the retractor blade handle is removable, the handle, and associated retractor blade, may be inserted into the clamping member in a direction that allows the locking position of the cam handle to extend towards the operative site. Furthermore, the lack of an integrated retractor blade handle increases the difficulty and time required for setting up and positioning the retractor blade relative to the patient's anatomy.
Because other components may be secured to the frame, it is desirable for a universal joint to have the capability of being added to the frame between secured components.
While universal joints with the above features have been designed, it is desirable to have a universal joint with even greater ease of use, flexibility, stability, and rigidity.
It is also desirable to have a universal joint that is designed so as to ensure that the cam handle of the cam locking mechanism is oriented away from the operative site.
Furthermore, it is desirable to improve the efficiency and ease of setting up a retraction system by reducing the number of individual components that must be independently added to the universal joint.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a universal joint apparatus. The present invention comprises clamps, a locking mechanism, and a rod associating the clamps with the locking mechanism. At least one clamp is a scissors clamp, i.e. a clamp comprising a first segment and a second segment, with the segments fastened by a pivot. The scissors clamp generates extra compressive force on the object being held, providing a stable and rigid universal joint. Clamps are able to rotate with respect to each other, allowing for greater flexibility in usage. The present invention is capable of being added to a support frame between other components. In one embodiment of the invention, the universal joint apparatus includes an integrated retractor blade handle, which, in conjunction with the cam locking mechanism, ensures that the locked position of the cam handle is oriented substantially away from the operating field.
These and other features, aspects, and advantages of the present invention will be better understood with reference to the accompanying drawings, descriptions, and claims.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a top perspective view of an embodiment of the present invention.
FIG. 2 is a partial bottom perspective view of the present invention.
FIG. 3 is a side view, in partial cross-section of an embodiment of the present invention.
FIG. 4 is a top view, in partial cross-section of an embodiment of a cam locking mechanism of the present invention.
FIG. 5 is a side view, in partial cross-section of an embodiment of a cam locking mechanism and rod of the present invention.
FIG. 6 is a top view, in partial cross-section, illustrating the operation of locking and unlocking an embodiment of the present invention.
FIG. 7 is a perspective view of one embodiment of the invention in which a retractor blade handle is integrated into the universal joint.
FIG. 8 is a side view of one embodiment of the invention in which a retractor blade handle is integrated into the universal joint.
FIG. 9 is a top view of a portion of a retraction system, the illustrated embodiment of the invention including an integrated retractor blade handle that is attached to a retractor blade.
FIG. 10 illustrates the use of a conventional surgical retraction system.
The foregoing summary, as well as the following detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the preferred embodiments of the present invention, there is shown in the drawings, embodiments which are presently preferred. It should be understood, however, that the present invention is not limited to the arrangements and instrumentality shown in the attached drawings.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 10 illustrates the use of conventional universal joints in a surgical retraction system 101 . Adjustable clamps 223 , 225 are secured, through the use adapters 140 , 145 , to the frames 150 , 155 of a conventional framed stretcher 160 . A post 170 extends vertically from a clamp 223 to provide support for a cross bar 180 , which in turn provides support for a pair of extension arms 190 , 200 . The crossbar 180 is secured to the post 170 by a universal joint clamp 210 . The extension arms 190 , 200 are secured to the cross bar 180 by a pair of universal joint clamps 220 , 240 . Additional universal joint clamps 260 , 280 are disposed along the extension arms 190 , 200 for rigidly securing any number of retractor blades 340 , 360 to the extension arms 190 , 200 .
The universal joints 260 , 280 allow for both the rotation of the clamping mechanism along the longitudinal axis of the extension arms 190 , 200 and the pivotable placement of the retractor blade handle 440 in relation to the extension arms 190 , 200 . The surgeon is then able to place the retractor blades 340 , 360 at their desired position in the incision 460 made by the surgeon. The retractor blades 340 , 360 are then used to retract the patient's anatomy, thereby making the incised opening accessible to the surgeon.
Referring to FIG. 1 , the disclosed embodiment of the universal scissors joint apparatus includes a first clamping member referred to as a scissors clamp 10 , a second clamping member referred to as a circle clamp 20 , a cam locking mechanism 30 , and a rod 40 . The rod 40 associates the cam locking mechanism 30 , the circle clamp 20 , and the scissors clamp 10 .
Referring to FIGS. 1 , 2 , and 3 , the scissors clamp 10 includes two segments connected at a pivot 16 , similar to a scissors, so that the two segments cross each other at the pivot 16 . The first segment 12 includes an upper portion, referred to as an upper handle 12 a , of the scissors clamp 10 proximal of the pivot 16 and engaging the rod 40 ; the first segment 12 further includes two lower portions, referred to as lower grippers 12 b , of the scissors clamp 10 distal of the pivot 16 . The second segment 14 includes a lower portion, referred to as a lower handle 14 a , of the scissors clamp 10 proximal of the pivot 16 ; the second segment 14 further includes an upper portion, referred to as an upper gripper 14 b , of the scissors clamp 10 distal of the pivot 16 . The grippers 12 b , 14 b of the scissors clamp 10 are shaped so as to contour the surface of the object (not shown) to which the clamp is being attached. The inner surface of the upper gripper 14 b of the scissors clamp 10 may include indentations 14 c . These indentations 14 c may be located opposite the lower grippers 12 b . The handles 12 a , 14 a of the scissors clamp 10 are separated by a gap that allows the scissors clamp 10 to be squeezed, creating a tighter grip on the instrument being held by the grippers 12 b , 14 b of the clamp. The handles 12 a , 14 a of the scissors clamp 10 each have an opening that allows the rod 40 to pass through. A bushing 50 may be used. The bushing 50 may surround the rod 40 and fit into the opening in the upper handle 12 a.
The circle clamp 20 includes an upper portion 22 and a lower portion 24 connected to form a single piece. The upper portion 22 and lower portion 24 are connected at a circular shaped fulcrum 26 . The fulcrum 26 has a circular hole 28 in it. The hole 28 allows for the insertion of a retractor, rail, or other object (not shown). Except for the connection at the fulcrum 26 , a gap exists between the upper portion 22 and lower portion 24 of the circle clamp 20 . The gap allows the circle clamp 20 to be squeezed, tightening the grip on the object being held in the circle clamp 20 . A spacer 60 may lie within this gap. Both the upper portion 22 and lower portion 24 of the circle clamp 20 have an opening through which the rod 40 may pass. The opening in the lower portion 24 may fit the same bushing 50 that engages the scissors clamp 10 .
Referring to FIGS. 1 , 4 , and 5 , the locking mechanism 30 includes a handle 32 connected to a cam 34 . The handle 32 consists of a first straight portion 32 a , an elbow 32 b , and a second straight portion 32 c . The first straight portion 32 a projects straight out from the cam 34 , then the elbow 32 b curves at an angle before the second straight portion 32 c projects straight out from the elbow 32 b . The second straight portion 32 c of the handle 32 includes a recessed area 36 . The cam 34 may be shaped asymmetrically with respect to the center axis 33 of the handle, so that the cam's center axis 35 is not aligned with the handle's center axis 33 . The cam 34 is positioned through an eyehole 42 in the rod 40 . Alternatively, the cam's center axis 35 may be aligned with the handle's center axis 33 where the cam 34 is not circular but instead has different radial lengths along different points of its perimeter, as will be appreciated by those skilled in the art.
Referring to FIGS. 3 and 5 , the rod 40 associates the scissors clamp 10 , circle clamp 20 and the cam locking mechanism 30 . The rod 40 has an eyehole 42 at one end through which the cam 34 may be inserted. At the opposite end, the rod 40 may be connected to a nut 70 . A spring 80 surrounds the rod 40 between the nut 70 and the lower handle 14 a of the scissors clamp 10 . Alternatively, the rod 40 may be directly attached to the lower handle 14 a of the scissors clamp 10 .
Referring to FIGS. 3 , 5 , and 6 , the universal scissors joint is engaged by rotating the cam handle 32 from an open position 38 to a locked position 39 . Rotating the cam handle 32 rotates the cam 34 within the eyehole 42 . This pushes the rod 40 upward, which causes the nut 70 and spring 80 to press upward on the lower handle 14 a of the scissors clamp 10 . Because the upper handle 12 a of the scissors clamp 10 is connected by the bushing 50 to the lower portion 24 of the circle clamp 20 , and the circle clamp 20 is a single piece, as the nut 70 and spring 80 move upward, both the scissors clamp 10 and the circle clamp 20 are squeezed, creating a tighter grip on the objects being held within the clamps.
Referring to FIGS. 1 , 3 , 5 , and 6 the scissors clamp 10 and the circle clamp 20 are able to rotate with respect to each other. This allows any attached rods or surgical devices to be positioned in any manner desired for surgery. The ability to rotate may be locked or unlocked by the locking mechanism 30 . When the cam handle 32 is in the open position 38 , the scissors clamp 10 and the circle clamp 20 are able to freely rotate with respect to each other. When the cam handle 32 is in the locked position 39 , the ability of the two clamps to rotate with respect to each other is made extremely difficult, with the result establishing a fixed position for the clamps with respect to each other so long as the cam handle 32 is in the locked position 39 . As the cam handle 32 is rotated into the locked position 39 , the upper handle 12 a of the scissors clamp 10 is pressed against the bushing 50 with greater force, and the lower portion 24 of the circle clamp 20 is also pressed against the bushing 50 with greater force. This greater force creates greater friction between the scissors clamp 10 and the bushing 50 and between the circle clamp 20 and the bushing 50 , greatly restricting the ability of the scissors clamp 10 and the circle clamp 20 to rotate with respect to each other.
FIGS. 7 and 8 illustrate an embodiment of the invention in which a dedicated retractor blade handle 105 is permanently mounted into the universal joint 90 . The handle 105 , passes through the circular hole 28 of the circle clamp 20 . In the illustrated embodiment, the handle 105 has a head member 110 and an end cap 116 , the head member 110 and end cap 116 being configured so that they are incapable of passing through the circular hole 28 , thereby preventing the handle 105 from being removed from the universal joint 90 .
FIGS. 7 and 8 also illustrate the cam locking mechanism 30 as being integrated into the universal joint 90 . More specifically, the cam handle 32 , cam 34 , and eyehole 42 are illustrated as being located in the upper portion 22 of the circle clamp 20 , with at least a portion of the cam handle 32 passing through, and rotating about, the orifice 21 of the upper portion 22 . The rotational engagement of at least a portion of the cam handle 32 with the orifice 21 prevents the cam locking mechanism 30 from being swiveled and/or rotated about the longitudinal axis 41 of the rod 40 independently of the position of the circular clamp 20 . Therefore, the orientation of the open position 38 or locked position 39 of the cam handle 32 always retains its position relative to the longitudinal axis of the circular hole 28 .
FIG. 9 illustrates a benefit of using an integrated handle 105 . Scissors clamp 10 is shown attached to an extension arm 118 . In this illustrated embodiment, because the handle 105 may not be removed from the universal joint 90 , the head 110 of the handle 105 , and associated retractor blade 340 , may be assembled so that the cam handle 32 may only be manipulated from an open position 38 , as illustrated by phantom lines, to a locked position 39 , as illustrated by solid lines, to a position that is oriented substantially away from the incised opening 460 in the patient's anatomy, thereby providing an easy and efficient means of ensuring that the cam handle 32 does not interfere with the surgeon's visual contact with patient's anatomy or impair the surgeon's movement.
In the illustrated embodiment, the open position 38 and locked position 39 of cam handle 32 is illustrated as being substantially parallel with the handle 105 . This reduces potential interference that may be associated with a cam handle 32 that substantially protrudes away from the retractor blade handle 105 . The longitudinal axis of the cam handle is slightly angled away from the longitudinal axis of the retractor blade handle 105 so that the retractor blade handle 105 does not interfere with the ability to hold and manipulate the orientation of the cam handle 42 .
Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. For example, types of clamps other than the circle clamp 20 may be used in conjunction with the scissors clamp 10 , and more than two clamps may be used in one device. It will be appreciated that different sizes and shapes of the clamps may be used without departing from the scope of the present invention. Different types of cam locking mechanisms may be used, such as that revealed in U.S. Pat. No. 5,888,197. Still other types of locking mechanisms may be employed, such as a threaded locking mechanism. It will be appreciated that the handle and the cam may assume different shapes without departing from the scope of the present invention. It will be appreciated that the positions that constitute the locked and unlocked position may be changed without departing from the scope of the present invention. The revealed embodiment is not able to be completely disassembled, so as to allow sterilization without disassembly, but other embodiments may be completely disassembled. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein. | A universal joint apparatus comprises clamps, a locking mechanism, and a rod connecting the clamps and the locking mechanism. At least one clamp is a scissors clamp, i.e. a clamp comprising two segments fastened by a pivot. The scissors clamp generates extra compressive force on the object being held, providing a stable and rigid universal joint. Clamps are able to rotate with respect to each other, allowing for greater flexibility in usage. The universal joint apparatus is capable of being added to a support frame between other components. In one embodiment of the invention, the universal joint includes a dedicated retractor blade handle to ensure that the locked position of the cam handle is oriented substantially away from the operative site. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of International Application No. PCT/EP2005/010192, filed Sep. 21, 2005 and German Application No. 10 2004 048 844.4, filed Oct. 4, 2004, the complete disclosures of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] a) Field of the Invention
[0003] The present invention is directed to an optical system for an illumination device of a microscope.
[0004] b) Description of the Related Art
[0005] To examine a specimen with a microscope, the specimen is usually illuminated by means of an illumination arrangement. In transmitted illumination, the light of the illumination arrangement is radiated through the specimen, whereas in incident illumination the illumination arrangement radiates light on the surface of the specimen that is examined by means of the microscope. Different requirements are imposed on the illumination arrangement for different illumination situations in incident light studies, for example, illumination for fluorescence microscopy at different wavelengths, darkfield illumination, white-light incident illumination, or structured incident illumination at different wavelengths.
[0006] In view of the different requirements for incident illumination, the construction shown schematically in FIG. 1 has proven useful. An illumination unit 1 with a light source 2 radiates a bundle of light rays on an optical system 4 with a collector 3 that images the light source 2 to infinity. First partial optics 5 generate an intermediate image of the light source 2 in an intermediate image plane and the intermediate image is imaged to infinity by second partial optics 6 . The bundle of light rays exiting from the second partial optics 6 is deflected by a tube lens 7 and a semitransparent mirror 8 to the objective 9 and, after passing through the objective 9 , illuminates an object 10 . In conformity to the basic rules of Köhler illumination, an aperture diaphragm 11 is arranged in the intermediate image plane between the partial optics 5 and 6 . The second partial optics 6 and the tube lens 7 image the intermediate image of the light source 2 in the objective pupil 12 . This construction makes it possible to place a field diaphragm 13 in a plane in which a sharp intermediate image of the objective image is formed, namely, in the focal plane of the tube lens 7 . Since a diffraction-limited intermediate image of the objective image is present in this plane, structures can be arranged which are then imaged with absolute sharpness on the object.
[0007] As a rule, neither the collector nor the partial optics are achromatic for reasons of cost. This leads to severe longitudinal chromatic aberrations of the light source image in the objective pupil. Particularly in illumination for fluorescence studies, these longitudinal chromatic aberrations cause a highly inhomogeneous illumination of the object field. This can only be avoided by readjusting the light source every time a filter is changed. This process is very cumbersome and makes the use of fast filter changers practically impossible.
[0008] This disadvantage can be overcome by using special collectors which are achromatic at least to the extent that the longitudinal chromatic aberration in the objective pupil is tolerable. However, such collectors have a very complicated construction.
[0009] Further, an intermediate image plane of the object image lies between the partial optics and the collector. Impurities in this intermediate image plane are imaged sharply on the object and considerably impede observation of the object. Elements of the achromatic collectors inevitably approach very close to this intermediate image plane, which leads to considerable problems with respect to the cleanliness of the collector lenses.
OBJECT AND SUMMARY OF THE INVENTION
[0010] Therefore, it is the primary object of the present invention to provide means for illuminating an object in microscopic examination which make it possible to illuminate in the wavelength range from 350 nm to 750 nm extensively without troublesome longitudinal chromatic aberrations in the objective pupil.
[0011] This object is met through an optical system for arranging between a light source and a field diaphragm in an illumination beam path of a microscope which comprises n imaging optical elements with focal lengths f i and Abbe numbers ν i (i=1, . . . , n) and for which the following relationship is met:
[0000]
∑
i
=
1
n
h
i
f
i
·
v
i
≤
0.07
,
[0000] where h i is one half of the bundle diameter of a bundle of light rays proceeding from a point of the light source at the entrance to the imaging optical element i. By the entrance to the lens is meant the location on the optical axis where the ray of the bundle of light rays that is at the greatest distance from the optical axis enters the lens. The focal length and the Abbe number are preferably given with reference to the yellow d-line of helium or the green e-line of mercury, i.e., wavelength 587.6 nm or 546.1 nm, respectively. By the Abbe number for the e-line, i.e., the green mercury line at 546.7 nm, is meant within the framework of the present invention, the Abbe number given by
[0000]
ν
=
n
e
-
1
n
F
′
-
n
C
′
,
[0000] where n F′ −n C′ is the difference of the refractive indices for the cadmium lines F′ and C′ at 479.99 nm and 643.85 nm, respectively, and n c is the refractive index for the green mercury line. By the Abbe number for the d-line, i.e., the yellow helium line at 587.6 nm, is meant within the framework of the present invention the Abbe number given by
[0000]
ν
=
n
d
-
1
n
F
-
n
C
,
[0000] where n F −n C is the difference of the refractive indices for the hydrogen lines F and C at 486.1 nm and 656.3 nm, respectively, and n d is the refractive index for the yellow helium line at 587.6 nm.
[0012] The system according to the invention carries out the function of a condenser in that it allows a uniform illumination of an object plane of a microscope or of a plane conjugate to the object plane. It is approximately apochromatic and makes it possible to image the light source in the intermediate image plane, or in an aperture diaphragm arranged therein, with only minor spherical aberrations and longitudinal chromatic aberrations or even with none at all. The imaging in the objective pupil is then corrected spherically as well as chromatically.
[0013] The system according to the invention can be used in particular for incident illumination in a microscope.
[0014] In the optical system according to the invention, the n optical elements preferably comprise a partial system which serves to image the light source from infinity to an intermediate image in the optical system, has a focal length f and comprises in direction of the beam path proceeding from the light source: a first converging lens with a focal length f 1 where 0.3 f<f 1 <0.7 f, a diverging lens with a focal length f 2 where −0.2 f<f 2 <−0.4 f, a second converging lens with a focal length f 3 where 0.3 f<f 3 <0.7 f, and a third converging lens with a focal length f 4 where 0.8 f<f 4 <2 f, wherein the distance of the third converging lens from the second converging lens is between 0.6 f and 1.2 f. By the distance between two lenses is meant the distance on the optical axis of the surfaces of the lenses facing one another.
[0015] The optical system can further have a collector portion in front of the optical partial system which images the light source to infinity and, behind the optical partial system, another optical partial system which images the intermediate image generated by the optical system to infinity. Since the image of the light source in the intermediate image plane is already extensively corrected spherically and chromatically, no special requirements need be imposed on this additional optical system.
[0016] The optical partial system of the optical system according to the invention preferably has exactly four lenses.
[0017] In order to achieve imaging without longitudinal chromatic aberrations as far as possible, the material of the first converging lens and second converging lens of the optical partial system has a low dispersion. Accordingly, it is preferable in the optical system according to the invention that the Abbe number of the material of the first and/or second converging lens of the optical partial system is greater than 60.
[0018] Further, in order to prevent longitudinal chromatic aberrations as far as possible, it is preferable that the material of the diverging lens of the optical partial system has a high dispersion. In particular, it is preferable that the Abbe number of the material of the diverging lens of the optical partial system is less than 50.
[0019] In principle, the third converging lens of the optical partial system need not have an especially low dispersion. To keep longitudinal chromatic aberrations to a minimum, however, it is preferable in the optical system according to the invention that the Abbe number of the third converging lens of the optical partial system is greater than 50.
[0020] Aberrations are reduced particularly when the first three lenses of the optical partial system, i.e., the first converging lens, the diverging lens, and the second converging lens, have very small air separations relative to one another. In particular, it is preferable in the optical system according to the invention that the distance between the first converging lens and the diverging lens of the optical partial system and the distance between the diverging lens and the second converging lens of the optical partial system are less than 0.05 f.
[0021] An illumination in which aberrations are conspicuously absent is achieved by a preferred embodiment form of the optical system according to the invention in which the optical partial system has a focal length f=50.76 mm and the parameters radius r 1 of the entrance surface, thickness d of the lens, radius r 2 of the exit surface, distance a to the following lens, refractive index n, and Abbe number ν have the following values:
[0000]
r 1
d
r 2
a
Lens
in mm
in mm
in mm
in mm
n
ν
first
32.08
8.00
−23.21
1
1.49
70.18
converging
lens
diverging
−21.91
3.00
16.55
1.11
1.65
33.6
lens
second
18.97
11.00
−23.21
46.81
1.49
70.18
converging
lens
third
15.18
3.00
30.07
50.48
1.52
63.96
converging
lens
[0022] By refractive index is meant in this connection as well as in the following the index of refraction at 546.1 nm unless otherwise expressly indicated.
[0023] Illumination which is especially free from aberrations is achieved in particular in a preferred embodiment form of the optical system according to the invention which has seven lenses and in which the parameters radius r 1 of the entrance surface, thickness d of the lens, radius r 2 of the exit surface, distance a to the following lens, refractive index n at a wavelength of 546.1 nm, and Abbe number ν have the following values:
[0000]
r 1
d
r 2
a
Lens
in mm
in mm
in mm
in mm
n
ν
first
−141.25
7.2
−12.23
0.3
1.46
67.77
collector lens
second
54.25
5.8
−25.12
40.09
1.52
59.22
collector lens
first
32.08
8
−23.21
1.00
1.49
70.18
converging
lens of the
first partial
system
diverging
−21.91
3
16.55
1.11
1.65
33.6
lens of the
first partial
system
second
18.97
11.00
−23.21
46.81
1.49
70.18
converging
lens of the
first partial
system
third
15.18
3
30.07
50.48
1.52
63.96
converging
lens of the
first partial
system
lens of the
−392.44
6.5
−24.58
1.52
63.96
second
partial
system
[0024] The invention will be described more fully in the following by way of example with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In the drawings:
[0026] FIG. 1 shows a schematic beam path of an incident illumination according to the prior art; and
[0027] FIG. 2 shows a schematic view of a condenser according to a preferred embodiment form of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] FIG. 2 shows a light source 2 with an optical system 14 according to a preferred embodiment form of the invention which is used instead of the collector 3 and partial optics 5 and 6 in FIG. 1 .
[0029] The optical system 14 has seven lenses and a collector portion for imaging the light source 2 to infinity with a first and second collimator lens 30 and 31 , respectively, a first optical partial system 15 , which images the image of the light source 2 generated by the collector portion to infinity on an intermediate image plane 16 , and a second optical partial system in the form of a lens 17 which images the image of the light source 2 in the intermediate image plane 16 to infinity.
[0030] The collector portion and the two optical partial systems are constructed as described in the following. The values indicated in this embodiment example for the refractive index refer to the e-line, i.e., the mercury line at 546.1 nm, the values for the Abbe number refer to the Abbe number in the e-line as described above.
[0031] The first lens 30 for the collector portion is a concave-convex lens having a thickness of 7.2 mm, a radius of curvature of 141.25 mm on the concave side 32 and a radius of curvature of −12.23 mm on the convex side 33 . The first lens 30 is made of a glass with a refractive index of 1.46 and an Abbe number of 67.77.
[0032] The second lens 31 of the collector portion, which is arranged at a distance of 0.3 mm from the first lens of the collector portion, is biconvex with a thickness of 5.8 mm and is bounded on the entrance side facing the light source 2 by a surface 34 with a radius of curvature of 54.25 mm and on the exit side by a surface 35 with a radius of curvature of 25.12 mm. The second lens 31 is made of a glass with a refractive index of 1.52 and an Abbe number of 59.22.
[0033] The first optical partial system 15 has four lenses and comprises a first converging lens 18 , a diverging lens 19 , a second converging lens 20 , and a third converging lens 21 considered in the direction of the incoming light.
[0034] The first converging lens and second converging lens 18 and 20 , respectively, are made of a material, glass in the present example, with low dispersion and with a refractive index of 10.49 and an Abbe number of 70.18.
[0035] The entrance-side surface 22 of the first converging lens 18 , which is arranged at a distance of 40.09 mm from the second lens 31 of the collector portion, has a radius of 32.08 mm, the second, exit-side surface 23 has a radius of −23.21 mm, and the thickness of the converging lens 18 is 8 mm.
[0036] The second converging lens 20 having a thickness of 11 mm is bounded by an entrance-side surface 24 with a radius of 18.97 mm and an exit-side surface 25 with a radius of −23.21.
[0037] The diverging lens 19 is made of a material, glass in the example, with a high dispersion having a refractive index of 1.65 and an Abbe number of 33.60. The diverging lens 19 with a thickness of 3 mm is bounded by an entrance-side first surface 26 having a radius −21.91 mm and by an exit-side second surface 27 having a radius of 16.55 mm.
[0038] The first converging lens 18 and the diverging lens 19 , and diverging lens 19 and the second converging lens 20 , are arranged with a small air separation therebetween of a 1 =1.00 mm and a 2 =1.11 mm, respectively.
[0039] Finally, the third converging lens 21 is arranged at a distance of a 3 =46.81 mm from the second converging lens 20 . It is made of a material, glass in the example, having a low dispersion with a refractive index of 1.52 and an Abbe number of 63.96. The third converging lens 21 with a thickness of 3 mm is bounded by an entrance-side surface 28 with a radius of 15.18 mm and an exit-side surface 29 with a radius of 30.07 mm. The distance from the next optical element, the optical system 17 , is 50.48 mm.
[0040] The collector portion and the first optical partial system 15 generate a spherically and chromatically corrected image of the light source in the intermediate image plane 16 .
[0041] The second optical partial system 17 comprises a concave-convex lens which is at a distance of 50.48 mm from the third converging lens 21 and which has a thickness of 6.5 mm and is bounded on the entrance side by a surface 36 with a radius of curvature of 392.44 mm and on the exit side by a surface 37 with a radius of curvature of −24.58 mm. The material of the lens 17 has the same refractive index and the same Abbe number as the material of the third lens 20 of the first partial system 15 .
[0042] A surface has a negative radius when it curves out in the direction of illumination, i.e., its vertex lies foremost in the illumination direction (see FIG. 2 ).
[0043] A bundle of rays whose cross section changes when passing through each of the lenses of the optical system proceeds from a point of the light source 2 arranged in the focal point of the collector system. In the following, h 1 denotes one half of the bundle cross section at the entrance of the respect lens i, i.e., in the plane orthogonal to the optical axis, in which the outermost rays of the bundle enter the lens i (i=1 to 7 in direction of the illumination beam path). The position of the plane is shown by way of example in FIG. 2 for i=2.
[0044] In this case, the optical system has the values shown in the following table for the parameters of the lenses radius r 1 of the entrance surface, thickness d of the lens, radius r 2 of the exit surface, distance a to the following lens, refractive index n at a wavelength of 546.1 nm, and Abbe number ν e , the values also shown in the table for the focal length f in mm and one half of the bundle diameter h in mm.
[0045] Summation gives:
[0000]
∑
i
=
1
n
h
i
f
i
·
v
i
≤
0.068
.
[0046] The optical system allows a further reduction of longitudinal chromatic aberrations in the objective pupil with illumination in the wavelength range from 350 nm to 750 nm.
[0047] While the foregoing description and drawings represent the present invention, it will be obvious to those skilled in the art that various changes may be made therein without departing from the true spirit and scope of the present invention.
[0000]
r 1
d
r 2
a
f
h
Lens
in mm
in mm
in mm
in mm
n
ν e
in mm
in mm
first collector lens
−141.25
7.2
−12.23
0.3
1.46
67.77
28.6
9.5
second collector lens
54.25
5.8
−25.12
40.09
1.52
59.22
33.57
12.49
first converging lens
32.08
8.00
−23.21
1.00
1.49
70.18
28.9
10.91
of the first partial
system
diverging lens of the
−21.91
3.00
16.55
1.11
1.65
33.6
−14.02
9.91
first partial system
second converging
18.97
11.00
−23.21
46.81
1.49
70.18
23.34
9.95
lens of the first partial
system
third converging lens
15.18
3.00
30.07
50.48
1.52
63.96
55.3
2.19
of the first partial
system
lens of the second
−392.44
6.50
−24.58
1.52
63.96
50.25
9.9
partial system
REFERENCE NUMBERS
[0000]
1 illumination unit
2 light source
3 collector
4 optical system
5 first portion
6 second portion
7 tube lens
8 semitransparent mirror
9 objective
10 object
11 aperture diaphragm
12 objective pupil
13 field diaphragm
14 optical system
15 first optical partial system
16 intermediate image plane
17 second optical partial system
18 first converging lens
19 diverging lens
20 second converging lens
21 third converging lens
22 entrance-side surface
23 exit-side surface
24 entrance-side surface
25 exit-side surface
26 entrance-side surface
27 exit-side surface
28 entrance-side surface
29 exit-side surface
30 first collector lens
31 second collector lens
32 entrance-side surface
33 exit-side surface
34 entrance-side surface
35 exit-side surface
36 entrance-side surface
37 exit-side surface | An optical system for arranging between a light source and a field diaphragm in an illumination beam path of a microscope comprises n imaging optical elements with focal lengths f i and Abbe numbers ν i (i=1, . . . , n). The following relationship is met for the optical system:
∑
i
=
1
n
h
i
f
i
·
v
i
≤
0.07
,
where h i is one half of the bundle diameter of a bundle of light rays proceeding from a point of the light source at the entrance to the imaging optical element i. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/103,611 filed Oct. 9, 1998.
FIELD OF THE INVENTION
The invention relates generally to the field of wireless communication systems and more particularly to frequency reuse schemes utilizing base station antennas with notched patterns.
BACKGROUND OF THE INVENTION
A communication system generally includes three components: transmitter, channel, and receiver. The transmitter modulates the signal over the channel. The receiver demodulates the received signal to produce an estimate of the original message. The channel provides a connection between the transmitter and the receiver.
Two types of two-way communication channels exist, namely, point-to point channels and point-to-multipoint channels. Examples of point-to-point channels include wires (e.g., local telephone), microwave links, and optical fibers. Point-to-multipoint channels enable multiple receivers to be reached simultaneously from a single transmitter (e.g. cellular radio telephone communication systems and Local Multipoint Distribution Systems (LMDS)). For broad geographical coverage, a plurality of geographically dispersed transmitters may be employed, each one's coverage area being known as a cell. Directional antennas may be employed at the transmitters, each one covering a portion of a cell known as a sector.
One factor that limits the capacity of a point-to-multipoint radio system is interference from transmitters using the same frequency in different cells, thus restricting the allocation of frequencies However, there are some known frequency reuse schemes which improve the available capacity.
Typically the present state of the art limits reuse of frequencies to N=4 (i.e. each sector operates in a frequency chosen from a predetermined group of four frequencies) for high order modulation schemes. Although reuse schemes have been proposed based on N=2 or N=1, these schemes are in many cases dubious in performance, particularly for high level modulation schemes such as 16 Quadrature Amplitude Modulation (QAM) or 64 QAM, since they typically fail in deployment.
Cellular frequency reuse schemes have been designed and employed with omnidirectional antennas at the terminal equipment and with hexagonal cells. However, in conventional LMDS systems, highly directional antennas are used at the remote terminal equipment with quadratic orientation of base station antennas (i.e. four-sided cells).
FIG. 1A depicts a cell in a conventional LMDS system. A base station 10 is nominally at the center of cell 20 . Base station 10 is equipped with four antennas (not shown), each having a nominal 90-degree coverage pattern. The four antennas are aimed 90 degrees apart, thus dividing the cell 20 into four sectors 30 . Each of the four antennas operates on a different frequency, each frequency represented by a different orientation of hatching in a sector 30 .
FIG. 1B illustrates an LMDS frequency reuse scheme employing a plurality of base stations arrayed on the landscape so as to cover a large area with overlapping cells. The same four frequencies (represented by the four orientations of hatching) are reused a number of times. Some cells use the four frequencies in different positions than the representative cell of FIG. 1 A.
An analysis of the scheme illustrated in FIG. 1B shows that with the highly directional antennas at the remote terminal equipment, interference is localized to very narrow zones along the lines connecting multiple base stations. For example, communications to a remote unit located in sector A would be interfered with by base station transmissions in sector B, but not from transmissions from sectors C, D, or E even though sectors C, D, and E operate on the same frequency as sectors A and B. Thus, the interference zones reflect the antenna patterns of the remote terminal equipment.
However, there still exists a need for a better reuse system in LMDS.
There is a need for systems which use base-station antennas that are omnidirectional or “pseudo omnidirectional” (i.e., exhibiting radiation over nearly all, but not entirely all, of 360 degrees.
Accordingly it is an advantage of the present invention to provide an interference-reducing frequency reuse scheme for use with LMDS.
It is another advantage of the present invention to provide a reuse scheme in which Local Multipoint Distribution Systems (LMDS) base stations use omnidirectional or pseudo-omnidirectional base-station antennas with reduced interference.
These and other advantages of the invention will become apparent to those skilled in the art from the following description thereof.
SUMMARY OF THE INVENTION
In accordance with the teachings of the present invention, these and other advantages may be accomplished by the present systems and methods of frequency reuse schemes by employing notched antenna patterns.
In an exemplary embodiment of the invention, the system includes a frequency reuse scheme employing omnidirectional or pseudo-omnidirectional antenna patterns whereby the sector antenna pattern is designed to have directional notches in order to control interference to the surrounding cells.
In another embodiment the system includes a frequency reuse scheme whereby the angular locations of the notches in the antenna pattern are substantially matched to the positions and antenna patterns of the surrounding cells sharing that frequency.
In another embodiment the system includes a frequency reuse scheme whereby orthogonal polarization may be made available for co-channel in-cell repeaters.
In still another embodiment the system includes a frequency reuse scheme whereby the orthogonal polarization may be used for radio backhaul to a central base station from its surrounding base stations (either co-channel, adjacent channel or spread over multiple channels).
In another embodiment of the invention, the system includes a frequency reuse scheme whereby all channels may be used in all cells of a network.
Still another embodiment of the invention includes a frequency reuse scheme whereby all channels may be used in all cells of a network and reused to provide in cell repeaters using either copolar or cross polar polarization (dependent on location of the repeater).
In another embodiment of the invention, the system includes a frequency reuse scheme whereby intercell communication (e.g. backhaul) may be provided using a subset of all channels, the subset being determined by the frequency space patterns of the relevant cell pair.
The invention will next be described in connection with certain exemplary embodiments; however, it should be clear to those skilled in the art that various modifications, additions and subtractions can be made without departing from the spirit or scope of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more clearly understood by reference to the following detailed description of an exemplary embodiment in conjunction with the accompanying drawings, in which:
FIG. 1A depicts a cell in a conventional frequency reuse configuration for an LMDS wherein each cell is split into four sectors with each of the four sectors employing a different frequency and a directional base-station antenna;
FIG. 1B depicts a conventional frequency reuse configuration deployed in a network comprising a plurality of cells as depicted in FIG. 1A;
FIG. 2A depicts patterns of several antennas for use on LMDS base stations an accordance with the frequency reuse system of the present invention;
FIG. 2B depicts a composite of the patterns shown in FIG. 2A;
FIG. 3A depicts theoretical equivalents of the antenna patterns shown in FIG. 2A;
FIG. 3B depicts a composite of the patterns shown in FIG. 3A;
FIG. 4 depicts the patterns of FIG. 3A rotated by ninety degrees;
FIGS. 5A, 5 B, 5 C and 5 D depict an array of rectangular cells having antenna patterns according to the present invention, each Figure showing the patterns allocated to a different frequency;
FIG. 6 depicts antenna patterns for use in hexagonal cells according to the present invention.
FIGS. 7A, 7 B, 7 C, and 7 D depict an array of hexagonal cells having antenna patterns according to the present invention, each showing the patterns allocated to a different frequency;
FIGS. 8A through 8E illustrate propagation directions for backhaul communication on the same frequencies as subscriber communications;
FIGS. 9A, 9 B, and 9 C depict transmission paths that may be used for backhaul according to the present invention;
FIG. 10A depicts directional antenna patterns for use in another practice of the invention;
FIGS. 10B through 10D illustrate details of the characteristics of the antenna patterns of FIG. 10A;
FIGS. 11A through 11D each depict the allocation of one frequency channel to the antenna patterns of FIG. 10 A.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a novel frequency reuse scheme that enables fractional reuse for LMDS type systems using high order modulation (e.g. 4, 16 and 64 QAM). The scheme will be discussed with regard to Quad cell based systems, however those skilled in the art will appreciate that these schemes may also be applicable to hexagonal-cell-based systems and the like. The proposed reuse scheme uses the knowledge that highly directional terminal equipment localizes the interference to very narrow zones along the lines connecting multiple base stations in order to control the interference zones. It employs this knowledge by utilizing omnidirectional base station antennas with notched patterns, or pseudo-omnidirectional antennas formed from multiple directional antennas with or without notches to synthesize omnidirectional antennas with notches (hereinafter any reference to omnidirectional antennas will include pseudo-omnidirectional antennas) to increase capacity of the cell and to control interference from adjacent cells. Those skilled in the art will recognize that while it is preferable that the notch be the inverse function of a remote antenna, practical limitations dictate that the notch is often limited to a crude approximation. The depth of the notches is preferably limited to that necessary for adequate system performance (typically of the order of 10 dB at the remote antenna's 3 dB beamwidth) although it is not required to be so limited. The required notches for each of the reuse frequencies in each cell reside at different angular locations, thus enabling full 360 degree coverage with a varying number of channels available in each direction. Such a scheme as this does not require the use of polarization as an additional discriminator. The orthogonal polarization in this case is available to increase margins in difficult deployments, to provide isolation for in cell repeaters when required or to provide for RF backhaul sharing the same spectrum as the cellular network.
FIG. 2A shows typical radiation patterns 22 , 24 , and 26 that might be obtained from typical omnidirectional or pseudo-omnidirectional antennas. The patterns exhibit notches. FIG. 2A also shows pattern 28 that might be obtained from a directional antenna that might be used for backhaul communications. Each typically operates in a different frequency range, represented by the different orientations of hatching shown in each of the four patterns 22 through 28 . FIG. 2B shows the composite radiation pattern 20 that results in a cell as a result of equipping a single base station with antennas exhibiting the patterns 22 through 28 .
FIG. 3A depicts stylized hypothetical cell radiation patterns 32 through 38 that correspond to actual patterns 22 through 28 , respectively, of FIG. 2 A. FIG. 3B depicts composite pattern 30 , the composite of patterns 32 through 38 . To facilitate illustration and discussion, stylized composite pattern 30 of FIG. 3A will be discussed in the ensuing description rather than actual composite pattern 20 of FIG. 2 A. Based upon these patterns of FIG. 3 A and notches therein, the average coverage for the cell 20 will be 3.2 to 3.3 channels per location within the cell, determined graphically from the patterns of FIG. 3 A.
In an exemplary embodiment, some of the cells employ antenna orientations rotated ninety degrees from those depicted in FIG. 3 A. These orientations are shown in FIG. 4, in which elements 42 , 44 , 46 , and 48 are the rotated equivalents of FIG. 3 A's elements 32 , 34 , 36 , and 38 respectively.
The purpose and position of the notches is best understood from FIGS. 5A through 5D, which are schematic depictions of a geographically dispersed LMDS system employing four frequencies in each cell, denominated as channels 1 , 2 , 3 , and 4 . The FIGS. 5A through 5D each show the patterns to which a different one of the channels is allocated. The patterns from FIGS. 3A and 4 are arranged so that the notches reject interference from the base stations in some of the adjoining cells. The same four frequencies are reused in all the cells.
In FIG. 5B are depicted exemplary remote stations 54 , 55 , and 56 positioned at the edge of sector 50 and operating in channel 2 . The remote stations use highly directional antennas, and the exemplary ones would be aimed at the base station in the center of sector 50 . The nearest potentially interfering base station is the one in the center of sector 52 . (Other potentially interfering base stations, slightly farther away, are at the centers of sectors 51 and 53 .) However, the base station of sector 52 is at least five times as distant from remote station 55 as the base station of sector 50 . (If remote station 55 were closer to its base station, the sector 52 base station would be more than five times as distant.) Adjacent sectors do not interfere because of the patterns, notches, and directions thereof. Remote station positions within the same antenna lobe other than the ones shown would be subject to even less interference. The exemplary locations represent worst case.
Other embodiments of communication systems are based on modeling of cells as hexagonal cells. FIG. 6 depicts antenna patterns 61 through 66 for use in hexagonal cells according to the present invention. The patterns 61 through 66 are depicted as being stylized to hexagonal shape, though practical antennas would probably produce patterns with a more circular overall aspect. The patterns 61 through 66 are different orientations of the same basic pattern. Those skilled in the art realize that other patterns than those depicted may be used without departing from the spirit of the invention.
FIGS. 7A, 7 B, and 7 C depict a geographically dispersed network using hexagonal cells according to the present invention. Each shows a set of antenna patterns for a different one of three frequency channels, denominated as channels 1 , 2 , and 3 . Each base station has a set of three antennas (which may be composite antennas), each producing one of the six patterns 61 through 66 depicted in FIG. 6 .
FIG. 7D shows again the configuration of cell patterns for channel 2 given in FIG. 7 B and further shows exemplary remote stations 71 through 79 at worst-case locations at the edge of cell 700 . Of particular interest are remote stations 72 , 75 , and 78 . Remote station 72 , by virtue of having its highly directional antenna aimed at the base station in the center of cell 700 , also has its antenna aimed at the base station in adjacent cell 703 . The antenna selected for use on channel 2 in cell 703 , however, has one of its notches aligned with that communication path. Adjacent-cell interference between cell 703 and remote station 72 is thus eliminated. Analogously, adjacent-cell interference between remote station 75 and cell 78 , and between remote station 78 and cell 702 , is also eliminated.
The next nearest potentially interfering base stations are in cell 707 (at which remote station 77 's antenna is inherently aimed) and cell 709 (at which remote station 73 's antenna is inherently aimed). The distance from remote station 77 to the base station of cell 707 , however, is more than four times the distance from remote station 77 to its own base station in cell 700 , even with remote station 77 's worst-case location at the very edge of cell 700 . Other potentially interfering base stations are even further away.
FIGS. 8A through 8D illustrate how the present invention enables the use of 1 in 5 cells for backhaul on the same frequency channels that are being used for communication with the mobile cells. Each of these Figures depicts, for 36 cells, the assignment of one of the four frequencies to antenna patterns as discussed above and similarly shown in FIGS. 5A through 5D. Backhaul communication (from one base station to another) is accomplished using antennas separate from those used to communicate with mobile stations. The backhaul antennas have very narrow beams, on the order of three degrees in a preferred embodiment. A beam so narrow can be transmitted through the notches in antenna patterns 46 and 48 of FIG. 4 without causing significant response at any mobile stations located in those notches, since such mobile stations would be communicating with their base stations on one of the other frequencies in which they would not be in a notch relative to their base stations. Using a different polarization for subscriber communications and backhaul communication also helps eliminate interference with subscriber communication. Backhaul communication is not attempted through the notches in antenna patterns 42 or 44 of FIG. 4, since those notches are quite narrow and interference may occur.
Some paths are susceptible of supporting backhaul transmission on more than one frequency, in which case one frequency is chosen by the designer. FIG. 8E is a composite of the paths among the 36 depicted sectors that are possible according to the present invention using the same frequencies as are used for subscriber communication.
For the 36-cell example of FIGS. 8A through 8D, the number of wired backhauls is reduced from 36 to 15, approximately a 2.5:1 reduction on even a small network such as this. As network size increases the reduction approaches 5:1 asymptotically.
FIGS. 9A, 9 B, and 9 C show heavy arrowheads connoting transmission paths that may be used for backhaul on channels 1 , 2 , and 3 respectively. Antennas used for backhaul have very narrow beams. Beamwidths of three degrees or less are preferred. The choice of backhaul paths is so as to direct the narrow backhaul beams through notches that do not carry any customer traffic on a particular channel. Backhaul traffic may thus take place without interfering with subscriber traffic.
FIG. 10A shows polar plots of antenna patterns 102 , 104 , and 106 employed in another practice of the invention, with pattern 106 being employed twice. There is thus a total of four patterns, each having a coverage of nominally 90 degrees, with the four patterns being 90 degrees apart. This nominally divides a cell into four equal sectors. FIGS. 10B through 10D are minimum-performance Cartesian plots of the transmission patterns 102 , 104 , and 106 respectively. The notch depicted in FIG. 10D is 10 db. deep for 4 or 16 QAM modulation and 16 db. deep for 64 QAM modulation. A CPE (Customer Premises Equipment) antenna with a three-degree beamwidth and a typical installation error within plus or minus 1.5 degrees will work with the indicated notches.
FIGS. 11A through 11D show a network comprising cells each deploying the four antenna patterns of FIG. 10 A. Each cell on each of the Figures is a mirror image of its neighbors, if the neighbors are considered one at a time. In going from one of the frequency allocations to the next, the patterns in each sector are rotated 90 degrees clockwise.
The systems described will optimally work when the base station spectral power density is constant, and also when the received spectral power density is constant. Those skilled in the art may employ known techniques of power control for achieving these conditions.
It will thus be seen that the invention provides apparatus and methods of frequency reuse schemes in LMDS and similar systems. Those skilled in the art will appreciate that the configurations depicted in FIGS. 2-11 increase capacity of the cells while maintaining an acceptable level of interference from other cells.
It will be understood that changes may be made in the above construction and in the foregoing sequences of operation without departing from the scope of the invention. It is accordingly intended that all matter contained in the above description or shown in the accompanying drawings be interpreted as illustrative rather than in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention as described herein, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween. | The invention provides frequency reuse techniques to enable fractional frequency reuse to be achieved for various cellular radio deployment grids, even for high order modulation such as 16 QAM and 64 QAM by the use of controlled and coordinated notched antenna patterns. The technique allows all frequencies to be used in all cells, thus maximizing system capacity while minimizing and controlling adjacent cell interference by the use of notched antenna patterns. | 7 |
TECHNICAL FIELD
This invention relates to a process for carburizing ferrous metals and in particular to a process wherein a furnace atmosphere is created by injecting nitrogen and ethanol separately or as a mixture into a furnace. Carbon potential of the furnace atmosphere can be established and maintained by control of the total flow of input components during the carburizing cycle as well as control of and/or addition of water in the input mixture and the addition of enriching or carburizing agents in the input composition.
BACKGROUND OF THE PRIOR ART
Carburization is the conventional process for case hardening of ferrous metals, e.g. steel. In gas carburizing, the steel is exposed to an atmosphere which contains components capable of transferring carbon to the surface of the metal from which it diffuses into the body of the part. After an appropriate amount of carbon has been transferred, the steel is removed from the furnace and rapidly quenched, whereupon those regions in which the carbon level has been raised become hard and wear-resistant.
A variety of atmospheres have been employed, but they share a number of features in common. They must not react with the steel to form oxides or other undesirable compounds. This requirement precludes the presence of oxygen, and more than small amounts of water or carbon dioxide. Second, they must contain a substance which can serve as a carbon donor to the surface of the steel. Most commonly this is carbon monoxide, but occasionally hydrocarbons or oxygenated organic materials are employed. Third, the atmosphere must activate the surface of the steel so that reaction with the carbon donor proceeds at an acceptable rate. Hydrogen is highly effective as an activator, and is invariably present in practical carburizing atmospheres. Atmospheres derived from a variety of sources have been employed, but the most commonly used one is the so-called endothermic gas produced by partial combustion of natural gas in air. It consists essentially of 40% nitrogen, 40% hydrogen and 20% carbon monoxide. It is usually necessary to add a small amount of another constituent, commonly natural gas, to raise its carbon potential.
The use of endothermic atmospheres has a number of disadvantages. An expensive and elaborate endothermic gas (endogas) generator which requires continuing maintenance and attention of an operator is needed. Furthermore, the gas generator cannot be turned on and off at will; once it is running it is necessary to keep it in operation even though the demand for the atmosphere may vary from a maximum load to zero. The endogas, and the natural gas required to produce it, are wasted during periods of low demand. Further, natural gas is not constant in composition, containing varying amounts of ethane, propane and higher hydrocarbons in addition to the main constituent, methane. Variability in natural gas composition causes substantial changes in the endogas produced, and gives rise to problems of control. Finally, burning increasingly scarce and expensive natural gas to produce an atmosphere is inherently wasteful of energy.
A more recent development in the production of carburizing atmospheres involves the use of inexpensive by-product nitrogen which is introduced into the carburizing furnace along with methanol. The latter is thermally decomposed to produce a mixture of hydrogen and carbon monoxide, which serves as a carburizing atmosphere. It is usually necessary to add another constituent, frequently natural gas, to raise the carbon potential of such atmospheres. However methanol is commonly produced from natural gas or petroleum, and as fossil fuel becomes scarcer and more expensive, this approach again represents a waste of valuable energy.
There have been attempts to use ethanol, which may be produced from renewable agricultural products, for the generation of atmospheres for carburization. For example, U.S. Pat. No. 2,673,821 describes the generation of a furnace atmosphere from a mixture of ethanol and water. Control of carbon potential and prevention of massive carbon deposition (sooting) is achieved by addition of water. However, blue-black surfaces are reported in the literature for the hardened pieces indicating that incipient sooting took place. Further, since no constituent other than ethanol containing a relatively small amount of water is employed for generation of the atmosphere, excessive cost and wastage are experienced.
British Pat. No. 816,051 describes in general terms a process whereby nitrogen is saturated with a volatile organic substance and passed into a heat-treating furnace to generate an atmosphere suitable for carburization. Although no details are given, it is stated that ethanol may be used in this process. However, in Traitement Thermique, 62 (1971) 35-45 published by Traitement Thermique, 254 Rue de Vaugirad 75740 Paris, France, the authors state that only methanol and acetone are suitable in this process. Ethanol is reported to produce gum in the exit port of the furnace and to cause only weak and irregular carburization.
BRIEF SUMMARY OF INVENTION
Ferrous metal articles can be effectively carburized utilizing nitrogen and ethanol mixtures directed into a carburizing furnace simultaneously as discrete streams or as a mixture. In a first embodiment of the invention carburization is effected by controlling the amount of water in the ethanol and the ratio of ethanol to nitrogen, as well as the total flow of the components through the furnace. A second embodiment of the invention resides in a process utilizing a nitrogen-ethanol base mixture supplemented by the addition of controlled amounts of water and a hydrocarbon enriching or carburizing agent. Either embodiment includes control of the carbon potential of the furnace atmosphere by controlling input composition and total flow through the furnace.
DETAILED DESCRIPTION OF INVENTION
It has been found that steel may be successfully carburized by heating it in a furnace into which a mixture of nitrogen and ethanol is passed. The carbon potential of the atmosphere is continuously determined by a suitable means such as an iron wire sensor. Alternatively, the atmosphere may be continuously analyzed for the concentrations of carbon monoxide and carbon dioxide by a gas chromatograph, or by infrared analysis. The carbon potential can be calculated from these gas analyses.
The flow of ethanol is varied in order to maintain the desired carbon potential. An increase in ethanol flow rate results in an increase in carbon potential while a decrease in carbon potential may be achieved by reducing the ethanol flow rate. Since the rate at which carbon is absorbed by the steel declines as its carbon content increases, it is usually necessary to begin the operation with a certain flow rate and decrease the rate as the run progresses.
The ethanol may be anhydrous, or it may contain water. Commercial 95% (190 proof) ethanol is a convenient product for use in this process, but water levels of up to about 15% by volume may be accommodated. It may be advantageous in cases where a relatively low carbon potential is desired to use ethanol containing these greater quantities of water. Water lowers the carbon potential at a given ethanol flow rate.
The ethanol may be introduced into the furnace either by vaporizing it into the nitrogen stream or by spraying it through a nozzle directly into the furnace along with the nitrogen. The quantity of ethanol which is employed ranges from as low as about 1% to as high as about 50% with the usual preferred range being about 10 to 20% depending on temperature, desired carbon potential and the surface area of the load of steel parts to be carburized. The total flow rate through the furnace may range from as low as 2 to as high as 6 standard volume changes per hour with a usual preferred range being from about 3 to about 4 standard volume changes per hour. At higher flow rates incomplete decomposition of ethanol may occur with resultant relatively low carburizing efficiency. Much lower flow rates may give rise to problems in leaky furnaces where air will reduce carbon potentials excessively.
This first embodiment of the invention is best understood by reference to Example 1 and Table I wherein there is set out a series of tests conducted to illustrate this part of the invention.
EXAMPLE 1
For the tests a 7.5 cubic foot batch-type furnace heated with alloy radiant tubes and provided with a circulating fan was used to carburize a load consisting of American Iron and Steel Institute (AISI) type 1010 steel rivets. The rivets were placed in the furnace which was then closed and fed with nitrogen and ethanol at the flow rates indicated in Table I. The furnace was brought to the indicated operating temperature in 30 minutes and then was held for 21/2 hours at temperature.
TABLE I______________________________________Fce. Fce. Input Composition.sup.(1) Furnace Comp.Run Temp. Load % by Volume % by VolumeNo. °F. Wt. N.sub.2 EtOH H.sub.2 O H.sub.2 CH4 CO______________________________________1 1550 15 lb 91.4 7.3 1.3 16.6 1.0 9.15(843° C.) (25) (2.0) (0.34)2 1550 15 lb 88.7 9.6 1.7 24.5 1.8 12.00(843° C.) (25) (2.7) (0.47)3 1700 15 lb 88.7 9.6 1.7 22.0 0.5 11.65(927° C.) (25) (2.7) (0.47)4 1700 15 lb 82.8 14.7 2.5 30.4 1.0 13.90(927° C.) (25) (4.45) (0.76)5 1700 60 lb 77.8 18.9 3.3 35.0 1.4 15.71(927° C.) (25) (6.1) (1.05)______________________________________Furnace Comp.% by Volume CaseRun D. P. Pco.sup.2 / Depth Hard-No. CO.sub.2 °F..sup.(2) Pco.sub.2 % C. Inches ness, Rc______________________________________1 0.068 +10 12.3 0.67 0.014 51.00.058 +5 14.4 0.762 0.087 +18 16.6 0.87 0.018 55.00.087 +18 16.6 0.850.087 +18 16.6 0.883 0.041 -4 33.4 0.71 0.024 55.00.031 -4 44.1 0.900.027 -4 49.6 1.014 0.034 +5 56.9 1.20 0.030 60.00.034 +5 56.3 1.170.034 +5 56.9 1.085 0.048 +10 51.5 1.16 0.028 47.00.046 +10 53.4 1.130.045 +10 55.2 1.15______________________________________ .sup.(1) Flow rate in Standard Cubic feet per hour shown (). .sup.(2) Dew Point
Composition of the furnace atmosphere is indicated, as is the percentage carbon in a shimstock test piece and case depth and hardness attained in the rivets. The parts were clean and without soot deposit. The increased carbon potential attained with increasing ethanol flow rate is demonstrated in runs 1-4. The larger load in run 5 required a greater ethanol flow rate to maintain the same carbon potential as that in run 4.
From the foregoing it has been demonstrated that ferrous metal parts can be effectively carburized utilizing an ethanol-nitrogen mixture injected into a furnace by controlling the amount of water in the ethanol and the total flow of ethanol and nitrogen through the furnace.
In another embodiment of the invention a suitable base furnace atmosphere similar in composition to that derived from nitrogen and methanol can be produced by passing into a furnace a stream of nitrogen to which has been added ethanol and water in a 1 to 1 molar ratio. The mixture of ethanol and water is obtained by adding 0.31 liters of water to every liter of anhydrous (100%) ethanol, or 0.265 liters of water to every liter of commercial 95% (190 proof) ethanol. The final percentage of water in the liquid mixture is approximately 24% by volume. At furnace temperatures of about 1500° to about 1900° F. (816° to 1038° C.) the ethanol and water react to produce a gas containing carbon monoxide and hydrogen in an approximately 1 to 2 ratio, along with small quantities of methane, carbon dioxide and water. The resulting furnace atmosphere can be used for neutral hardening of low carbon steels. If it is desired to cause carburization, the carbon potential of the atmosphere may be raised by addition of an enriching gas such as natural gas containing substantially methane, propane, butane, ethane and mixtures thereof. The carbon potential of the atmosphere is continuously determined by a suitable means such as an iron wire sensor. Alternatively, the atmosphere may be continuously analyzed for the concentrations of carbon monoxide and carbon dioxide by means of a gas chromatograph or by infrared analysis. The carbon potential can be calculated from these gas analyses, and adjusted upwards or downwards by changing the rate of addition of enriching gas. An increase in the quantity of enriching gas causes a rise in carbon potential while a lowering of carbon potential results when the flow of enriching gas is diminshed. Control of enriching gas flow can be manual, or can be achieved automatically using well known and commonly available equipment.
The following examples illustrate the manner of practicing this invention.
EXAMPLE 2
A 7.5 cu. ft. batch type furnace provided with radiant tube heaters and a circulating fan was employed to demonstrate the generation of typical furnace atmospheres and to show that these could be effectively used for the carburization of steel parts. In the first series of experiments the furnace was operated without a load while the amount of propane added was varied over a substantial range. The ethanol and water were sprayed separately as liquids into the furnace through the port which was also employed for the introduction of gaseous nitrogen. Propane was introduced into the nitrogen stream prior to entry into the furnace. A sample of furnace atmosphere was continuously withdrawn and was analyzed at frequent intervals by means of a gas chromatograph. A strip of steel shimstock 0.005 cm (0.002 in.) in thickness was suspended in the furnace to provide a measure of carbon potential. At termination of the run the shimstock was rapidly withdrawn, cooled and analyzed for carbon.
The results are shown in Table II. The column headed Percent C Theoretical (Theor.) is the theoretical carbon potential calculated from the individual analyses for carbon dioxide and carbon monoxide. The column headed Percent C Shim is the actual analysis of the Shimstock sample carbon. It is evident that calculated and measured values of carbon potential are in excellent agreement.
TABLE II______________________________________ FurnaceFce. Input Flow SCFH.sup.(1) AnalysisTemp °F. N.sub.2 C.sub.2 H.sub.5 OH H.sub.2 O C.sub.3 H.sub.8 H.sub.2.sup.(2) CH.sub.4.sup.(2)______________________________________1550 20 3 3 -- 30.59 1.46(843° C.) (77.0) (11.5) (11.5)1550 20 3 3 0.75 32.43 1.61(843° C.) (74.8) (11.2) (11.2) (2.8)1550 20 3 3 1.15 34.04 1.47(843° C.) (73.7) (11.0) (11.0) (4.3)1700 20 3 3 -- 28.88 0.94(927° C.) (77.0) (11.5) (11.5)1700 20 3 3 0.75 33.51 0.41(927° C.) (74.6) (11.2) (11.2) (2.8)1700 20 3 3 1.15 35.36 0.81(927° C.) (73.7) (11.0) (11.0) (4.3)______________________________________Furnace AnalysisFce. D.P. % C. % C.Temp °F. CO.sup.(2) CO.sub.2.sup.(2) °F..sup.(3) Pco.sup.2 /Pco.sub.2 Theor. Shim______________________________________1550 14.94 1.08 +34 2.1 0.18 0.11(843° C.)1550 15.84 0.21 +34 11.9 0.87 0.67(843° C.)1550 15.43 0.19 -0 12.5 0.92 0.94(843° C.)1700 14.11 0.87 +30 2.3 0.08 0.09(927° C.)1700 17.12 0.10 -8 29.3 0.81 0.77(927° C.)1700 17.86 0.08 -18 40.0 1.05 1.02(927° C.)______________________________________ .sup.(1) () Composition in % by volume .sup.(2) Percent by volume .sup.(3) Dew Point
EXAMPLE 3
The furnace and procedure described in Example 2 were employed for the carburization of two 15 lb. charges of AISI type 1010 rivets. The input flows and furnace gas analyses are shown in the following Table III.
TABLE III______________________________________ FurnaceRun Fce. Input Flow SCFH.sup.(1) AnalysisNo. Temp °F. N.sub.2 C.sub.2 H.sub.5 OH H.sub.2 O C.sub.3 H.sub.8 H.sub.2.sup.(2) CH.sub.4.sup.(2)______________________________________1 1700 20 3 3 1.15 36.93 1.08(927° C.) (73.7) (11.9) (11.0) (4.3)2 1550 20 3 3 1.15 33.18 4.48(843° C.) (78.7) (11.0) (11.0) (4.3)______________________________________Run Furnace Analysis % C. % C.No. CO.sup.(2) CO.sub.2.sup.(2) D.P. °F..sup.(3) Pco.sup.2 /Pco2 Theor. Shim______________________________________1 18.12 0.008 -15 37.3 0.99 1.122 17.43 0.25 +34 12.2 0.90 0.85______________________________________ .sup.(1) () Composition in % by volume .sup.(2) Percent by volume .sup.(3) Dew Point
The rivets were withdrawn from the furnace after 21/2 hours at temperature in each run, cooled and subjected to a metallographic examination to determine total and effective case depth. The results of these determinations are shown in Table IV.
TABLE IV______________________________________ Case Depth (inches)Run No. Temp. °F. Total Effective______________________________________1 1700 0.035 0.017 (927° C.)2 1550 0.016 0.007 (843° C.)______________________________________
The results are entirely satisfactory and in the case of run 2 at 1700° F. are virtually identical to those obtained at the same temperature with an atmosphere derived from methanol, nitrogen and natural gas.
The base gas forming components sent to the furnace may range from about 0% nitrogen, about 50% ethanol and about 50% water up to about 85% nitrogen, 7.5% ethanol and 7.5% water. The preferred maximum quantity of nitrogen in the feed gas is about 80% with the remainder being about 10% ethanol and about 10% water. Higher nitrogen content may result in unsatisfactory low rates of carburization. The minimum nitrogen content depends upon the particular application. In some circumstances, a base gas derived entirely from ethanol and water may prove advantageous at the beginning of a carburizing run by providing a maximum and uniform rate of carbon transfer. However, such atmospheres are expensive and it is desirable to begin dilution with nitrogen when the high carbon transfer rate can no longer be maintained.
The ratio of ethanol to water is preferably about 1 to 1, although higher ratios may be employed to achieve somewhat higher carbon potentials. Ratios significantly below 1 to 1 should be avoided since they may lead to decarburization and/or oxidation of the steel. The ratio of enriching gas to ethanol may vary from 0 up to a value which produces the desired carbon potential in the furnace. A precise general statement for this upper limit cannot be given since it depends upon many factors including not only the desired carbon potential, but also the furnace temperature, rate of gas circulation, and surface area of the parts being carburized. The values given in Example III are typical of what may be experienced when propane is used as an enriching gas. It is obvious that larger quantities of substances containing less carbon per molecule than propane will be required. The temperature may range from about 1500 to about 1900° F. (816 to about 1038° C.).
The water and ethanol may be introduced separately or in a combined stream either as liquids or vapors. In general, the most simple operation will result when the liquids are thoroughly mixed and then pumped and metered into the furnace as liquids through a spray nozzle or other suitable device which insures rapid and complete vaporization and dispersion of vapors throughout the furnace.
STATEMENT OF INDUSTRIAL APPLICATION
Processes according to the present invention can be used in place of existing gas carburizing processes in batch type furnaces and with proper furnace control in continuous furnaces. Existing furnaces can be readily adapted to the process of the present invention without the need to modifying existing carbon potential measuring equipment.
Having thus described our invention what is desired to be secured by Letters Patent of the United States is set out in the appended claims. | A process for carburizing ferrous metal articles in a furnace under an atmosphere derived from an input of nitrogen and ethanol injected into the furnace during the entire cycle. Carburization is controlled in a first embodiment by the control of ethanol and nitrogen mixture and water vapor content of the mixture as well as total flow through the furnace and in a second embodiment by controlling the nitrogen-ethanol mixture to which is added water and an enriching or carburizing agent. | 2 |
This application is a continuation of application Ser. No. 08/370,259, filed Jan. 9, 1995, abandoned.
The present invention relates generally to the structure of ladders. More specifically, it refers to such structures which, in addition to ladder feet, employ other means to stabilize a ladder.
It is well-known that ladders, and in particular extension ladders, are basically unstable. Even in the circumstance when the feet of the ladder are placed against a firm and level support or base, the longer the ladder the less stable the ladder becomes. Because ladders are normally of the same width at the top and bottom, basic physics dictates that when one wishes to make a very tall object stable, the base should be wider than the top and not of the same width as a ladder at the top, especially if a large portion of the weight of the ladder is distributed evenly through-out its length. As a consequence, a ladder would be far more stable were it wider at its base then at its top, and were the weight of the ladder concentrated near its base. Unfortunately, this is simply not the case with existing ladders.
Ladder instability has been widely recognized by those of skill in the art, and a number of patents disclose inventions designed to meet deficiencies of extension ladders for lack of stability.
An example of the prior art in this field is U.S. Pat. No. 4,147,231 to Chantler et al. Other prior art that exemplifies the present state of the art include U.S. Pat. No. 4,244,446 to Mair, and U.S. Pat. No. 4,632,220 to Murrell. In all of these prior patents a ladder is outfitted with what are referred to as outriggers or shoe members that serve as supports, in addition to the feet that form a part of all ladders. The supports extends from the ladder stiles of which they are a part, toward the base surface on which the ladder rests. Yet it will be apparent that many of these prior art ladder supports are deficient. Preliminarily, such prior ladder stabilizers are attached to their ladder. This makes the ladder heavier and more cumbersome to carry and to erect. In addition, when the ladder breaks or becomes inutile, the ladder extension must also be discarded, since the extension or outrigger is part of the ladder. Also, with regard to such supports, those that are fixed to the ladder stiles are generally of equal length. As a consequence, when the ladder stabilizer is attached to the ladder stiles in a fixed location, on uneven ground downhill pressure on the ladder may cause the foot on the higher side to "walk" inwardly, which then stabilizes the ladder at a dangerous, non-perpendicular angle.
Other types of ladder extensions, such as those identified in U.S. Pat. Nos. 4,872,529 and 4,899,849, are adjustable with telescoping tubular pole members. It will be immediately apparent that such telescoping members are not as strong as a solid piece of metal, for example, tubular steel, and that the rubber plugs inside the tubular poles will wear and slip with use. Further the poles, themselves, can kink at any time, rendering them useless.
It will thus be apparent that there exists a need for a ladder extension that will be simple and safe in design, can be economically manufactured to result in a reasonable sales price, and can readily be adjusted to support a ladder over a wide variety of terrains in such a manner that supports extending outwardly from both stiles reach equally and to their full extent, so that a full measure of support is provided in either direction regardless of the level of the terrain. The structure of the present invention has been designed with these features and advantages in view. As a consequence, the structure of the present invention has no folding or telescoping parts that sacrifice strength and stability in the name of storage convenience. Further, there is nothing to slip or wear out and the present device is useful regardless of the terrain and supports a ladder equally and outwardly of both stiles.
SUMMARY OF THE INVENTION
In its basic form, the present invention comprises a safety extension for a ladder having opposed, parallel stiles adapted to support a plurality of spaced rungs between them. The stiles conventionally terminate in feet for supporting the ladder against a base surface, e.g., the ground. Each safety extension according to the present invention comprises two elongated struts joined at one of their respective ends to form a V-shaped juncture between them from which the free ends of the struts extend. A clamp is attached to each of the struts at its free end, the clamps being dimensioned to enable them to contact and grasp one of the stiles so that the struts are clamped to said stile at spaced locations along the length of the stile. Finally, means for contacting the base surface is located substantially at the V-shaped juncture of the struts, and thereby provides an area of support for the ladder against the base surface in addition to that provided by the feet of the ladder.
In normal use two safety extensions will be provided, each having the same structure as outlined hereinbefore, and each being attached to a stile by means of clamps attached to the free ends of each strut. As so constructed, and particularly where the ground or the base surface is uneven, i.e., lower on one side of the ladder than on the other, the clamping means of the extension on the down-slope side will be attached to the stile on that side at lower positions of attachment than on the upper-slope stile. In this manner the outward reach of the ladder extensions will be the same on either side of the ladder and the ladder will be equally supported regardless of the slope of the base surface on which it is supported.
In other features, the stabilizing means attached to the V-shaped angle at which the two struts of an extension are joined constitutes a foot for contacting the base surface with at least as much in area as the stile foot. The stabilizing means may include a substantially planar pad for contact with the base surface. Also, in a preferred embodiment, the pad or other stabilizing surface is attached to the V-shaped juncture of two struts by a clevis type of arrangement, wherein two ears extend upwardly from the pad, and have aligned orifices through which a pin extends. An element fixed to the juncture is mounted on the pin, permitting rotation of the pad relative to the strut juncture in case the surface on which the pad rest is uneven.
With respect to the structure by means of which the free ends of the struts are removably clamped to the ladder stiles, such structure may include a U-shaped clamp housing adapted to fit over and grasp side walls of the strut. The U-shaped housing is formed from two brackets held in U-shape by a screw that extends through a slot in at least one of the L-shaped elements. At the end of the screw within the U-shaped housing, a gripper plate is mounted so that when a handle at the other end of the screw is rotated, the gripper plate is forced against the side of the ladder stile, thus maintaining the gripper plate, clamp and strut fixed to one of the brackets in place on the ladder stile. After the ladder has been used, it is a simple matter to counterrotate the screw by its handle and remove the extension from the ladder.
These and other features and advantages of my invention will become more apparent when taken in connection with a detailed description of a preferred embodiment thereof, in which
FIG. 1 is a front elevational view showing ladder stabilizers according to my invention mounted in place on a ladder located on a flat surface;
FIG. 2 is a front elevational view similar to that of FIG. 1, except that the ladder and extensions or stabilizers are located on sloping terrain;
FIG. 3 is a perspective view of a clamp suitable for use with the present invention, with parts thereof spaced apart, and
FIG. 4 is a top plan view of an assembled clamp according to FIG. 3 of my invention.
DETAILED DESCRIPTION
In FIG. 1 a conventional ladder 10 is shown in such a position that it is resting against the side of a structure (not shown). The ladder 10 has two stiles 11 and 12 separated by rungs 13. At its lower most extension the ladder rests on a base surface, such as the ground 15 and is maintained thereon by feet 16 and 17. Its uppermost end a portion of a ladder extension 18 is shown.
As generally illustrated in FIG. 1, ladder stabilizing extensions 20 and 21 are indicated by arrows at either side of the ladder 10. The structures of the stabilizing extensions are duplicated, not only structurally but with respect to their position in FIG. 1, since the base surface 15 is level. Thus, stabilizing extension 20 consists of two elongated struts 23 and 24 joined in permanent relationship at a juncture 25. As will be seen, upper strut 23 is of greater length than lower strut 24 and is fixed to it at juncture 25 to form a generally V-shaped structure. As presently advised, an interior angle 26 formed by the V is preferably about 25 degrees. Of course, the greater the angle of the V-shaped juncture, the greater will be the distance between the ends of struts 23 and 24 at their free ends and, as a consequence, the greater will be the linear separation between the free ends of struts 23 and 24 at locations where they are adjacent to the stile 11.
At their upper ends struts 23 and 24 are attached, preferably fixedly, to clamps indicated generally by arrows 28 and 29. The structure of such clamps will be more fully described hereinafter with respect to FIGS. 3 and 4.
Just below the V-shaped juncture 25 is means for contacting base surface 15. The purpose of such means is to provide an area of support for the ladder against the base surface in addition to the support provided by ladder feet 16 and 17. Such support means 30 includes a foot 31 which is an actual contact with the ground, upstanding ears 32 having axially aligned orifices therethrough, and a pin 43 rotatably mounted in such aligned orifices. A juncture support 44 is affixed to the base of the V-shaped juncture 25 and is mounted on the pin 43 for rotation therewith. In accordance with the best mode of the present invention, the juncture support 44 is mounted in fixed relation to the pin 43 within the aligned orifices of the extension support 30. In this way as pin 43 rotates, juncture support 44 and the V-shaped juncture or elbow 25 also rotate. Alternatively, pin 43 can be fixedly mounted in ears 32 and support 44 rotate about pin 43, or the support 44 can be rotatable and the pin 43 rotatable in ears 32 as well.
The present invention has particular applicability when, as is often the case, the ladder rests on uneven ground. Such circumstance is illustrated in FIG. 2. As will there be seen, while in FIG. 1 extensions 20 and 21 were affixed by clamps to the ladder 10 at substantially equal locations along the ladder stiles 11 and 12, extensions 20 and 21 are now attached at differing positions in FIG. 2. There the base surface 18 slopes downwardly from left to right. In such circumstance ladder 10 thus has a chock 29 placed under its down-slope foot 16, and up-slope ladder foot 17 remains substantially without additional support.
In order to compensate for the slope of base surface 18, clamps 28 and 29 are illustrated in FIG. 2 as attached to stile 11 at locations that are lower along stile 11 than are corresponding clamps of ladder extension 21 attached to stile 12. Because of such lower attachment on stile 11, V-shaped juncture 25 is now in a lower position so that enlarged foot 31 is in substantially flat and broad contact with the base surface at its lower level. Because the angle 26 of the V-shaped juncture 25 remains the same, the struts 23 and 24 being permanently joined at that juncture, there is no diminution in the strength of ladder support 20 of its new position. Yet, as will be apparent, it provides great additional support to the ladder 10, even on sloping ground.
The structure of a preferred embodiment of the clamp of the present invention will now be described with reference to FIGS. 3 and 4. For the purpose of illustration, in FIG. 3 clamp 28 is illustrated with strut 23 affixed to one part of the clamp. However, the structure will be the same for all the other clamps used to hold the ladder extensions 20 and 21 to their respective stiles 11 and 12. With reference to FIGS. 3 and 4, strut 23 is fixed to the face of L-shaped bracket 33 which is then placed in conjunction with another L-shaped bracket 34 as shown in FIG. As so associated, clamp part 33 overlies the face of clamp part 34 so that a screw 35 extends through slot 36 in part 34 as well as through an appropriate orifice in part 33. Screw 35 terminates at one end in knob 38. It terminates inwardly of the clamp in a gripper plate 40. As will be apparent, because of the use of stud 41 between the knob 38 and clamp bracket 33, rotation of the knob 38 in a clockwise direction will result in the screw 35 being rotated clockwise to move inwardly of the brackets 33 and 34. At the same time the gripper plate 40 attached to the inner extension of screw 35 will be moved inwardly. Thus, clockwise rotation of knob 38 forces grip plate 40 against stile 11 of the ladder 10 and rotation is maintained until that grip plate is in a position to releasably hold the ladder extension 20 in position, e.g., the position shown in FIGS. 1 or 2. In that instance clamp 29 will also be affixed to stile 11 in a similar manner, and ladder extension 21 will be clamped to stile 12 by the same devices.
As has been disclosed in this preferred embodiment of my invention, the ladder extensions are readily detachable from the ladder with which they are to be used. As a consequence, they carry an distinct advantage regarding previous ladder stabilizers that are permanently attached to a ladder, making the ladder heavier and more cumbersome to carry and put in place. Because my ladder extension is not permanently secured to the ladder, it can easily be removed for storage and adjusted in seconds as the terrain on which the ladder is used varies. For storing convenience, my ladder extensions can simply be detached from the ladder and stored separately and conveniently. This is a distinct advantage over ladder extensions that are permanently attached to the ladder, which often require folding or telescoping parts that sacrifice strength and stability in the name of storage convenience. Every part that is critical to the structural stability of the present invention is welded solidly in place, e.g., the V-shaped juncture 25, so that there are no joints whose structural stability is mitigated because of the need to vary the angle of the joint to accommodate different ground slopes or for the purpose of storage.
While my invention has been described with reference to a specific embodiment thereof, which is presently deemed to be the best mode, it will be apparent to those of skill in this art that certain modifications and alterations of that preferred embodiment may be found obvious. As to all such alterations and modifications, it is desired that they be included within the purview of the present invention, which is to be limited only by the scope, including equivalents, of the following, appended claims. | A safety extension attached to the two ladder stiles and extending outwardly therefrom. Each extension is attached at two spaced locations along a ladder stile and terminates outwardly and downwardly in a V-shaped junction to which a stabilizing foot is attached. | 4 |
This application claims priority from U.S. Provisional Application 60/732,944, for a “Snow Pusher,” filed Nov. 3, 2005 by Michael P. Weagley et al., which is also hereby incorporated by reference in its entirety.
The following disclosure is directed to aspects of an improved snow or material pusher for use with loaders, backhoes, agricultural and larger home and garden tractors and the like for moving snow or other materials on generally flat areas such as parking lots, driveways, feed lots, runways, and loading areas, for example.
BACKGROUND AND SUMMARY OF THE INVENTION
A “pusher” or “pushing apparatus,” as described for example in U.S. Pat. No. 5,724,755 to Weagley (issued Mar. 3, 1998) or the folding material plow of U.S. Pat. No. 6,112,438, to Weagley et al. (issued Sep. 9, 2000), both hereby incorporated by reference in their entirety, generally include sides extending forward from a mold board or central blade to assure material being pushed (e.g., snow, liquids, debris, sludge, etc.) remains in front of the pusher, and is not directed to one or both sides as with conventional plows.
The following disclosure is directed to aspects and embodiments of an improved pusher design, including several aspects that can be employed on traditional pusher designs in order to improve the use and efficiency of such pushers. The disclosed aspects and embodiments, alone and in combination, improve the functionality, reliability, ease of use and/or safety of pushers.
In accordance with an aspect of the embodiments disclosed herein, there is provided a material pushing apparatus, comprising: an upstanding central blade including a first longitudinal edge and a second longitudinal edge along an opposite side of said blade, and left and right ends; a vertical side plate attached to and extending forward at a generally perpendicular angle from each of the ends of the central blade; a first cutting edge attached to the central blade along the first longitudinal edge; and a second cutting edge attached to the central blade along the second longitudinal edge.
In accordance with another aspect disclosed herein, there is provided a reversible coupler for use with a reversible implement, comprising: a first coupler portion suitable for attachment to a vehicle in a first orientation; and a second coupler portion suitable for attachment to the vehicle in a second orientation.
In accordance with another embodiment, there is disclosed a method of using a reversible pusher, comprising: connecting a vehicle to the pusher in a first orientation having a first cutting edge adjacent a surface upon which the pusher rests; advancing the pusher with the first cutting edge adjacent the surface; disconnecting the pusher from the vehicle; reconnecting the vehicle to the pusher in a second orientation having a second cutting edge adjacent the surface; and advancing the pusher with the second cutting edge adjacent the surface.
In accordance with a further aspect, there is provided an improved scraping edge for attachment along a longitudinal edge of a moldboard, comprising: a flexible base, removably attached to the moldboard, along a top portion of the base; a rigid cutting edge extending along and removably attached to said flexible base along a bottom portion of the base, wherein said flexible base flexes to allow the cutting edge to bypass immovable objects it contacts; and a tensioner to bias said flexible base into a partially flexed position.
In accordance with yet another aspect of the invention, there is provided a material pushing apparatus, comprising: an upstanding moldboard including a bottom longitudinal edge, and left and right ends; a vertical side plate attached to and extending forward at a generally perpendicular angle from each of said left and right ends of the moldboard; and a scraping edge attached to the moldboard along said bottom longitudinal edge, said scraping edge including, a flexible base, removably attached to the moldboard, along a top portion of the flexible base using at least one hold-down member; a rigid cutting edge extending along and removably attached to said flexible base along a bottom portion of the base, wherein said flexible base flexes to allow the cutting edge to bypass immovable objects it contacts; and a tensioner to bias said flexible base into a partially flexed position.
In accordance with a further aspect disclosed herein there is provided a material pusher, comprising: an upstanding central blade including a lower longitudinal edge and left and right ends; a vertical side plate extending forward at a right angle from each end of the central blade; and removable wear shoe attached along a bottom edge of each vertical side plate, wherein the removable wear shoe extends from a position adjacent a front edge of the vertical side plate to a position at least 6 inches beyond a rear surface of the moldboard so as to assure that a bottom surface of the wear shoe remains in complete contact with a surface on which the pusher is used.
In accordance with yet a further aspect of the following disclosure there is provided an extended wear shoe for use on a material pusher, comprising: a web for attachment to a side plate of the pusher; a generally horizontal lower surface for sliding contact with the ground, the lower surface transitioning to front and rear ramped surfaces on either end thereof; and a cap, permanently attached to the web and the upper end of the rear ramped surface thereof.
Disclosed in accordance with another embodiment is an improved scraping edge for attachment along a longitudinal edge of a pusher moldboard, comprising: a plurality of rigid sections; said sections being attached along the longitudinal edge using fasteners having a low yield strength and hardness such that one or more sections are dislodged from a normal operating position upon contact with an immovable object to thereby prevent damage to the object.
Also disclosed with respect to yet a further embodiment is a material pushing apparatus, comprising: an upstanding central blade including a lower longitudinal edge and left and right ends; a vertical side plate extending forward at a right angle from each end of the central blade; and a breakaway cutting edge, comprised of a plurality of rigid sections, attached to the central blade along the longitudinal edge, wherein at least one of the sections is dislodged from its normal operating position upon sufficient contact with an immovable object to prevent damage to the object.
In accordance with a further aspect disclosed herein there is provided a material moving apparatus, comprising: an upstanding moldboard including a bottom longitudinal edge, and left and right ends; a vertical side plate attached to and extending forward at a generally perpendicular angle from each of said left and right ends of the moldboard; and a scraping edge attached to the moldboard along said bottom longitudinal edge, said scraping edge including a rigid component and means for assuring that said rigid component yields upon coming in contact with an immovable object.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-4 illustrate various features and aspects of a switchblade, reversible coupling pusher in accordance with one embodiment;
FIGS. 5A-5H illustrate various features and aspects of a switchblade, reversible coupling, pusher in accordance with an alternative embodiment, where FIGS. 5A-5H particularly illustrate steps of using the reversible coupling feature with a skidsteer type vehicle;
FIGS. 6-7 illustrate various embodiments of a flexible trip edge in accordance with another aspect of the invention;
FIGS. 8-10 illustrate various embodiments of a breakaway edge in accordance with another aspect of the invention;
FIGS. 11A and 11B are illustrative side views of alternative embodiments of a snow pushing apparatus employing an extended wear shoe.
DETAILED DESCRIPTION
As used herein the figures are intended to be exemplary in nature, not limiting, and some or all aspects depicted may not be to scale. As will be further contemplated, various aspects of the disclosed embodiments have particular application to alternative snow removal and material moving technologies and while described in accordance with snow pushers and material pushing apparatus, are not intended to be limited to such embodiments. Accordingly, several of the aspects described herein may find particular use in plow, scraper, drag plow and similar applications in the same manner as described relative to snow or other material pushing embodiments.
Referring first to FIGS. 1-5H , various aspects of a switchable/reversible orientation or Switchblade™ pusher configuration will be discussed in detail, along with a reversible coupling mechanism associated therewith. FIGS. 1 and 3 , for example, illustrate a switchable orientation material pushing apparatus 110 . The intent of such a device is to provide two different types of scraping edges (e.g., hard and/or flexible) in a single material pusher so that a user can accommodate many different material conditions. In particular, the apparatus is believed to find practical use in its ability to handle new-fallen snow as well as hard-packed and re-frozen snow and ice that accumulate in parking lots and other heavily traveled areas.
Referring specifically to FIGS. 1-3 , Switchblade pusher 110 includes an upstanding central blade or moldboard 120 having a first longitudinal edge 130 and a second longitudinal edge 140 and left and right ends 150 , 160 , respectively. Also included is a vertical side plate 170 extending forward at a right angle from each of the ends 150 , 160 of the central blade 120 . A first cutting or scraping edge 180 is attached to the central blade or moldboard along the first longitudinal edge 130 , and a second cutting or scraping edge 182 is attached to the central blade along the second longitudinal edge 140 .
In one embodiment the Switchblade™ two-edged pusher has both a flexible polymer or rubber cutting edge 182 attached along a first longitudinal edge and a more rigid or steel cutting edge 180 along a second longitudinal edge. The flexible edge is perfect for wet, heavy snow conditions or jobsites where there are ground obstacles or imperfections in the surface being cleared. The steel edge 180 is ideal for hard packed snow conditions or jobsites that are flat with no ground obstacles. Alternatively, the steel edge 180 may be used on surfaces where some scraping and even removal of the top surface is desirable, for example, cleaning of animal barns and feedlots. Depending upon the situation the Switchblade pusher provides both types of edges on a single device.
One embodiment may include at least one flexible or rubber edge removably fastened to the central blade and extending along a longitudinal edge thereof. In FIG. 3 , a flexible rubber edge is generally depicted as 184 where the edge is reversible (by switching top for bottom), and is held to the face of the moldboard 120 using an elongated steel plate(s) as a hold-down member 185 . Moreover, it is contemplated that at least one cutting or scraping is removably fastened to the central blade along a longitudinal edge. As described above, at least one of the cutting edges comprises a rubber or flexible polymer edge 184 extending along and outward from one of the longitudinal edges of the central blade. As illustrated, such an edge is attached to the central blade 120 using a backing plate and bolts, and in some cases, the position of the edge may be adjusted upward or downward using slotted holes in the edge 184 through which the bolts are connected to nuts (not shown) behind the central blade.
It is further contemplated that one of the cutting edges of the reversible pushing apparatus may be a scraping edge 180 (see also 850 in FIG. 8 ), attached to the moldboard 120 along one longitudinal edge. The scraping edge 180 includes a rigid component and means for assuring that the rigid component yields upon coming in contact with an immovable object. In one embodiment, the scraping edge 180 may be a breakaway edge, wherein at least one of rigid components or sections is dislodged from its normal operating position upon sufficient contact with an immovable object to prevent damage to the object.
As is also shown in the figures, the pusher apparatus 110 further includes a pair of longitudinal wear shoes 190 along at least two edges of the side plate 170 . The wear shoes may be removable, as depicted, or may be permanently attached or mounted to the side plate. The wear shoes may also be extended as depicted, for example, in FIGS. 11A , B described below. The wear shoes 190 comprise inclined front and rear ramp surfaces 192 for sliding contact on the surface. In one embodiment, the front ends of wear shoes 190 and/or the side plates 170 , in conjunction, provide points or define a surface (along lines A-A′) that enables the apparatus to temporarily stand in an upright position, such as depicted in the embodiment of FIGS. 5B and 5C , in order to permit a vehicle to change the direction in which the apparatus is oriented for pushing—thereby changing from a first operating position where the first scraping edge is adjacent to the surface being cleaned to a second operating position whereby the second scraping edge is adjacent to the surface to be cleaned.
Considering FIGS. 1-3 and 5 A- 5 H, it will be apparent that the nature of the vehicle (skidsteer, backhoe or loader) is accommodated by one of several reversible couplers 210 , or similar reversible means for attaching the apparatus to a vehicle. The reversible coupler further enables the pushing vehicle 50 to be suitably attached, from either of two opposite directions. Where the vehicle 50 is a skidsteer-type or similar loader vehicle, the reversible coupler 210 includes a quick-coupling connection for both directions.
The reversible coupler 210 referred to above may be used with a reversible (Switchblade) pusher or with other reversible implements such as those known for use with skidsteer type vehicles. In one embodiment, reversible coupler 210 includes a first coupler assembly 220 , suitable for attachment to a vehicle (loader, skidsteer, etc.) in a first orientation, and a second coupler assembly 230 suitable for attachment to the vehicle in second first orientation. It will be appreciated that the first and second coupler assemblies are essentially mirror image replications of one another and may be contained within a common frame or assembly as depicted in FIGS. 5G and 5H , for example. It is further contemplated that a reversible pusher may have a plurality of non-mirrored couplers on the rear thereof, where one coupler is suitable for receiving a bucket of a loader or backhoe whereas another coupler is suitable for use with a skidsteer-type vehicle, thereby permitting a single pusher to be used with a plurality of vehicle types.
In the embodiment of FIG. 1 , each coupler assembly 220 , 230 includes two rows of parallel posts mounted on the rear of the pusher, the two rows of parallel posts form a slot 224 for receiving the edge of a bucket on the vehicle (not shown in FIG. 1 ). Referring to FIGS. 5C , F and G, for example, each reversible coupler assembly 210 is mounted on the rear of the pusher 110 and includes a pair of generally parallel side rails 250 , and opposed top members (e.g., downward facing flange) 254 , generally spanning between the side rails and providing a downward-facing pocket 256 on the rear of the pusher, the pocket receiving an upper edge or the like of a skidsteer attachment frame, and an angled foot or lower attachment member 258 on opposite ends, also spanning between the side rails, and suitable for receiving a lower wedge, pin or the like of the skidsteer attachment device. FIGS. 5E and 5F are illustrative examples of one method by which the skidsteer attachment device may be connected; first the attachment device of vehicle 50 is inserted into the pocket 256 and then, upon full connection of the attachment device with the coupler, the locking wedge or pin is inserted. It will be appreciated that various alternative means may be employed to interface with the reversible coupler 210 .
As an example of one possible configuration for the coupler assembly, FIGS. 5E-5H are referred to in order to illustrate the manner in which a skidsteer (e.g., Bobcat™) or similar vehicle is attached to the coupler. It will be appreciated that the coupler mechanism is duplicated in a mirrored configuration ( FIGS. 5F , G) to provide the reversible coupling referred to. It will also be appreciated that the coupler foot 258 may further include recesses, apertures 260 or similar features for receiving a locking wedge/detent or similar component or mechanism on the vehicle attachment frame—thereby providing positive attachment to the pusher. Alternatively, the pusher may be connected to the vehicle using well know means such as, hooks, clevises, chains and the like as is well known for connecting pushers to vehicles.
The coupler depicted in FIG. 5C is mounted on the rear of a pusher 110 and employs a common set of side rails such that both of the opposed coupling mechanisms form a single assembly suitable for coupling with a vehicle from opposite or reversible orientations.
Further referring to FIGS. 5A-5D , the sequence of figures illustrates a method for using a reversible pushing apparatus as described herein. The method includes connecting a vehicle 50 to the pusher in a first orientation ( FIG. 5A ), moving the pusher with a first edge adjacent the ground surface ( FIG. 5A ), standing the pusher on its “nose” (for example along the plane defined by line A-A′) as shown in FIG. 5B , disconnecting the vehicle from the pusher while in the “nose-down” position ( FIG. 5C ) and reconnecting the vehicle to the pusher in a second orientation ( FIG. 5D ), in order to subsequently move the pusher with a second edge adjacent the ground surface.
In an alternative method it is simply possible to use the vehicle 50 to roll or flip the pusher from one orientation to the other, thereby avoiding the need to temporarily place the pusher into a nose-down position. As will be appreciated, the vehicle should be disengaged from its respective coupler before flipping so as to enable the pusher to switch or reverse to the opposite orientation.
Referring next to FIGS. 6-7 there is depicted one embodiment of an improved scraping edge for use with the pusher described above, or with other conventional snow pusher designs, including those manufactured by Pro-Tech® and other manufacturers. In general, the improved scraping edge is attached to the central blade or moldboard along a longitudinal edge, and the scraping edge includes a rigid component and means for assuring that said rigid component yields upon coming in contact with an immovable object. In one embodiment, depicted in FIGS. 6-7 , the yielding means may include a flexible base member whereas in an alternative embodiment, depicted in FIGS. 8-10 , the yielding means may include a sacrificial fastener as well as similar components that flex or yield so that the cutting edge does not damage immovable objects it comes in contact with them.
The improved cutting edge of FIGS. 6-7 is designed for attachment along a longitudinal edge of a pusher moldboard 610 , and in a first embodiment comprises a flexible base 630 , removably attached to the moldboard, along a top portion of the base. In one embodiment, the attachment means includes a metal hold-down member 640 applied on the face of the flexible base 630 , wherein the flexible base is sandwiched between the hold-down member 640 and the moldboard 610 . Removably attached to the flexible base 630 , along a bottom portion thereof is a rigid cutting edge 650 , preferably made of steel and alloys thereof that exhibit high hardness and good wear resistance. The use of the flexible base as the means by which the rigid cutting edge is attached to the moldboard flexible permits flexing of the base and allows the cutting edge to bypass an immovable object that it contacts while the pusher moves and then return to a nominal operating position.
The flexible scraping edge base 630 may be made of a polymer (e.g., polyurethane), rubber or similar material, and is approximately 1.5 (1.0-2.0) inches thick. Such materials are available from CUE, Inc. (e.g., Compound No. PO-650) and exhibit approximately the following characteristics: shore durometer (ASTM D2240-64T) of 84 A; a compression set of 45% max.; a tensile strength (ASTM D412-61T) of 6000 psi; tensile modulus (ASTM D412-61T)@50% elongation of 500 psi; tear strength Trollsera (ASTM D1938)=250, Die C (ASTM D624)=470 and split tear (ASTM D470)=140; compression deflection (ASTM D575-46 Method A)@5%=300 psi; and abrasion resistance for Tabor (ASTM D3489-85(90)) of 15% rubber standard or NBS ASTM D1630-83=250.
In an alternative embodiment, the flexible scraping edge may further include a tensioner 660 to bias the flexible base into a partially flexed position. The use of a biasing means to pre-flex the base 630 assures that the base flexes rearward as the cutting edge 650 comes into contact with an immovable object such as a manhole, water-valve cap, curb, raised concrete or asphalt patch or similar objects. As will be appreciated, alternative biasing means including springs, pre-deformation of the base, tabs or stops along the side plates, etc. may be employed to assure that the polymer base 630 flexes rearward when the edge 650 contacts an immovable object. Absent a tensioner or other means for biasing or preflexing the base, the cutting edge may chatter and skip when contacting or moving over surfaces that are uneven yet generally free of immovable obstructions.
As further depicted in FIGS. 6 and 7 , the tensioner is removably attached to the moldboard using the same bolts employed for the metal hold-down member 640 . The tensioner includes an arm 662 that extends downward from where it is attached to the moldboard, and at the end of the arm there is a contact point 664 that applies a force or biasing contact to the metal cutting edge 650 , and the flexible base 630 is biased into the partially flexed (rearward) position as shown in the side view of FIG. 6 . It is also intended that the contact force or amount of bias applied to the cutting edge 650 is adjustable by way of bias adjusting bolt 668 , a threaded bolt at the end of the tensioner arm that establishes the contact point with the cutting edge in the embodiment depicted.
Those knowledgeable in the design of material pushers will appreciate that in an alternative embodiment a material pusher incorporating the improved cutting edge described above, may further include vertically extended or adjustable side plates and/or wear shoes, to provide increased or adjustable clearance between the bottom or the steel cutting edge 650 and the ground surface, thereby providing a region for the installation of the flexible cutting edge—and to provide a sufficient gap below the moldboard in which the edge can flex un an unconstrained fashion.
Turning next to FIGS. 8-11 , there is disclosed yet another embodiment of the breakaway cutting edge for use on a longitudinal edge of a material pusher or similar plow or pushing apparatus. In the design, the breakaway edge provides a cutting surface adequate to remove hard-packed snow or ice from a surface, yet prevents damage to immovable objects (e.g., manholes, sewercovers, curbs, etc.) that come into contact with the edge. The edge design assures that it becomes detached or “breaks away” from the moldboard upon striking such objects with sufficient force.
In one embodiment depicted in FIG. 10 , for example, the pusher comprises an upstanding central blade 810 having a lower longitudinal edge 820 and left ( 832 ) and right ends (not shown). A vertical side plate 840 extends forward generally at a right angle from each end of the central blade. The breakaway cutting edge 850 , comprises a plurality of sections 852 , attached to the central blade 810 along the longitudinal edge. At least one of the sections ( 852 ) may be dislodged from its normal operating position in response to the application of sufficient force resulting from contact with an immovable object, thereby preventing damage to the object.
As depicted in FIGS. 8 and 9 , an applied force Fx 1 is applied to the cutting edge by an immovable object when the pusher is being moved forward along the ground. The force is translated to resulting forces (e.g., Fx 2 ) and relative to opposing force (Fx 3 ) that place the fastener holding the edge 852 to the moldboard 810 , in tension and/or shear. As will be further appreciated, the force applied to the fastener is a function of not only Fx 1 , but also of the relative dimensions of the edge in relation to the moldboard's longitudinal edge, for example, dimensions 811 and 812 . For example, force Fx 1 translates to a significantly “magnified” force Fx 2 as a result of the leverage provided by a wide edge (e.g., dimension 811 ). As depicted, for example, in FIG. 8 , the forces applied to the fasteners holding edge 852 to moldboard 810 are also a function of the angle (θ) of the edge, which results in the addition of a shear stress applied to the fastener as well as a tensile stress.
Preferably, the longitudinal edge 820 of the central blade 810 is made of a material of sufficient strength, or is reinforced, to resist damage when the breakaway edge strikes an object. Moreover, the cutting edge sections 852 are made from or formed of steel or similar rigid and/or hardened materials, and are attached to the longitudinal edge using attachment hardware or fasteners (e.g., bolts with nuts as depicted in FIGS. 9 and 10 ) that offer less resistance to the applied stress (shear and/or tensile forces are present) than the cutting edge sections 852 , so as to result in the failure of the hardware/fasteners before damage to the object or the pushing apparatus. More specifically, in one embodiment, the edge sections are mounted to the central blade using bolts having a yield strength of less than about 36,000 psi and a tensile strength of less than about 74,000 psi (equivalent of Grade 2 or less). It will be appreciated that SAE-J429 Grade 1 or 2 (also A307 Grades A, B), may be used to assure that the failure of the bolts, by shear or other means, will occur before damage to the pusher components or the immovable object. It will also be appreciated that depending upon the particular application, the dimensions of the components, and/or sensitivity to damage, alternative fasteners sizes, steel alloys/grades, materials and or hardware components may be employed (e.g., aluminum hardware, shear pins, etc.) Although the angle θ is illustrated at approximately 12-degrees from normal, the embodiment depicted in FIG. 9 is believed best operated over a range of angles from about 5-degrees to about 20-degrees from normal, although use over a range of about 0-degrees to about 30-degrees from normal and higher is possible.
As generally depicted in FIG. 9 , the present invention further contemplates the use of a safety attachment mechanism 858 connecting the cutting edge sections 852 to the central blade or moldboard 810 so that in the event that the section is completely dislodged (i.e., all fasteners broken), the section will remain attached to the central blade for later reattachment. Such a mechanism may include a loop or hook welded to the back of the cutting edge and attached by chain, cable, clevis or the like to a similar loop or hook on the rear of the central blade.
Turning now to FIGS. 12A and 12B , there are depicted examples of extended wear shoes for use with a material pusher. The purpose of the extended shoe is to provide a larger surface on which the pusher rides, with the surface extending rearward from the coupling point, thereby making it easier for a vehicle operator to place the pusher in an orientation where the wear shoes are parallel to the ground or surface on which it is being used. Such a feature significantly decreases the likelihood that a pusher will be operated with only the front or rear edge contacting the surface, and thereby quickly wearing out that portion of the shoe. The improved, extended wear shoe 1210 includes a web 1220 for attachment to a side plate of a pusher, and a generally horizontal lower surface 1230 for sliding contact with the ground, the lower surface transitioning to front and rear ramped surfaces on either end thereof, and a cap, 1240 permanently attached to the exposed or extended portion of web 1220 and the upper end of the rear ramped surface. In other words, the cap covers and reinforces the web over at least part of the region 1250 where the shoe extends beyond the rear of the moldboard 810 , and as depicted in FIG. 12A that portion beyond the rear edge of the side plate.
As seen in FIGS. 12A-12B , the wear shoe extends a distance (region 1250 ) of at least about 10 to about 25% of the side plate length beyond the rear of the moldboard 810 , and as mentioned above beyond the coupling contact point between the vehicle and the pusher. Thus, the pusher has a removable wear shoe 1210 attached along a bottom edge of each vertical side plate, where the removable wear shoe extends from a position generally adjacent a front edge of the vertical side plate to a position well beyond the rear of the moldboard to assure that the majority of a bottom surface of the wear shoe remains in contact with the ground surface on which the pusher is used.
The present disclosure contemplates additional improvements to the wear shoe, that include at least a wear shoe lower horizontal surface 1230 made from a steel (e.g., HARDOX 500 (Super Duty) from SSAB Oxelsund AB with 0.26% Cr, 0.49% Si, 1.15% Mn, 0.010% P, 0.002 S, 0.070 Cr, 0.05 Ni, 0.009 Mo and 0.002 B) having a hardness of at least about 300 and more preferably about Brinnell. In such embodiments, a heavy duty shoe having improved wear performance may be fabricated using HARDOX 400 (Heavy Duty) or HARDOX 500 (Super Duty). HARDOX wear plate has a hardness of at least 300 and approximately 400 HB. It combines high wear resistance with toughness and good weldability. HARDOX is manufactured by SSAB Oxelosund AB. Use of the 400 and 500 grades is believed adequate, having a Brinnell hardness from about 300-550, to significantly reduce the wear of the shoes during normal pusher use. It will be further understood that the thickness of the lower horizontal surface of the various wear shoes may also be modified to provide longer shoe life.
It will be appreciated that various of the afore-described improvements and modifications may be applied or adapted to operate in conjunction with or on other types of pushers and material moving or scraping apparatus, including but not limited to, fold-out pushers and other types of snow plows and blades. It will be further appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims. | Disclosed herein are various aspects of an improved snow or material pushers for use with loaders, backhoes, agricultural and larger home and garden tractors and the like for moving snow or other materials on generally flat areas such as parking lots, driveways, feed lots, runways, and loading areas. The improvements include, among others, a reversible design, extended side plates and/or wear shoes as well as improved scraping edge configurations so as to provide added functionality and versatility to pushers. As described the various features may be employed alone or in combination to provide the capability for snow and ice removal while minimizing the potential for damage to surfaces and objects thereon. | 4 |
BACKGROUND
The gathering of downhole information has been done by the oil industry for many years. Modern petroleum drilling and production operations demand a great quantity of information relating to the parameters and conditions downhole. Such information typically includes the location and orientation of the wellbore and drilling assembly, earth formation properties, and drilling environment parameters downhole. The collection of information relating to formation properties and conditions downhole is commonly referred to as “logging”, and can be performed during the drilling process itself.
Various measurement tools exist for use in wireline logging and logging while drilling. One such tool is the resistivity tool, which includes one or more antennas for transmitting an electromagnetic signal into the formation and one or more antennas for receiving a formation response. When operated at low frequencies, the resistivity tool may be called an “induction” tool, and at high frequencies it may be called an electromagnetic wave propagation tool. Though the physical phenomena that dominate the measurement may vary with frequency, the operating principles for the tool are consistent. In some cases, the amplitude and/or the phase of the receive signals are compared to the amplitude and/or phase of the transmit signals to measure the formation resistivity. In other cases, the amplitude and/or phase of the receive signals are compared to each other to measure the formation resistivity.
When plotted as a function of depth or tool position in the borehole, the resistivity tool measurements are termed “logs” or “resistivity logs”. Such logs may provide indications of hydrocarbon concentrations and other information useful to drillers and completion engineers. However, such logs may exhibit limited spatial resolution and boundary-related artifacts that make interpretation difficult, particularly in situations where the borehole penetrates formations at an angle. Various techniques exist for processing logs to improve resolution and reduce artifacts, but such techniques may not be feasible for use in a real-time environment.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following detailed description of the various disclosed embodiments, reference will now be made to the accompanying drawings in which:
FIG. 1 shows an illustrative logging while drilling environment;
FIG. 2 shows an illustrative resistivity logging tool having tilted receiver antennas;
FIG. 3 provides a coordinate system for describing antenna orientation;
FIG. 4 shows a flowchart of an illustrative processing method to reduce artifacts in resistivity logs;
FIG. 5 shows illustrative logs of compensated phase difference, bed boundary indicator, and processed phase difference;
FIG. 6 shows illustrative resistivity logs determined from the compensated and processed phase differences; and
FIG. 7 shows an illustrative conversion of phase difference to resistivity.
While the described embodiments are susceptible to various modifications and alternative forms, specific examples thereof are shown for illustrative purposes and will be described in detail below. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the claims to the particular examples described, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
NOTATION AND NOMENCLATURE
Certain terms are used throughout the following description and claims to refer to particular system components and configurations. As one skilled in the art will appreciate, companies may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ”. Also, the term “couple” or “couples” is intended to mean either an indirect or a direct electrical connection. Thus, if a first device couples to a second device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections. In addition, the term “attached” is intended to mean either an indirect or a direct physical connection. Thus, if a first device attaches to a second device, that connection may be through a direct physical connection, or through an indirect physical connection via other devices and connections.
DETAILED DESCRIPTION
The foregoing background section identifies various potential shortcomings of existing resistivity logging systems and methods that are at least in part addressed by the systems and methods disclosed below. Some resistivity logging system embodiments include an azimuthally sensitive resistivity tool that makes at least one formation resistivity measurement and at least one boundary detection measurement that can be combined to reduce boundary-related artifacts in the formation resistivity measurement. Various logging method embodiments employ the boundary detection measurement to operate on the formation resistivity measurement to reduce boundary-related artifacts in a number of ways.
As one illustrative context for the disclosed systems and methods, FIG. 1 shows a well during drilling operations. A drilling platform 2 is equipped with a derrick 4 that supports a hoist 6 . Drilling is carried out by a string of drill pipes connected together by “tool” joints 7 so as to form a drill string 8 . The hoist 6 suspends a kelly 10 that lowers the drill string 8 through rotary table 12 . Connected to the lower end of the drill string 8 is a drill bit 14 . The bit 14 is rotated and drilling accomplished by rotating the drill string 8 , by use of a downhole motor near the drill bit, or by both methods.
Drilling fluid, termed mud, is pumped by mud recirculation equipment 16 through supply pipe 18 , through drilling kelly 10 , and down through the drill string 8 at high pressures and volumes to emerge through nozzles or jets in the drill bit 14 . The mud then travels back up the hole via the annulus formed between the exterior of the drill string 8 and the borehole wall 20 , through a blowout preventer, and into a mud pit 24 on the surface. On the surface, the drilling mud is cleaned and then recirculated by recirculation equipment 16 .
Logging while drilling (LWD) sensors 26 are located in the drillstring 8 near the drill bit 14 . Sensors 26 include directional instrumentation and a modular resistivity tool with tilted antennas for detecting bed boundaries. The directional instrumentation measures the inclination angle, the horizontal angle, and the rotational angle (a.k.a. “tool face angle”) of the LWD tools. As is commonly defined in the art, the inclination angle is the deviation from vertically downward, the horizontal angle is the angle in a horizontal plane from true North, and the tool face angle is the orientation (rotational about the tool axis) angle from the high side of the well bore. In some embodiments, directional measurements are made as follows: a three axis accelerometer measures the earth's gravitational field vector relative to the tool axis and a point on the circumference of the tool called the “tool face scribe line”. (The tool face scribe line is drawn on the tool surface as a line parallel to the tool axis.) From this measurement, the inclination and tool face angle of the LWD tool can be determined. Additionally, a three axis magnetometer measures the earth's magnetic field vector in a similar manner. From the combined magnetometer and accelerometer data, the horizontal angle of the LWD tool can be determined. In addition, a gyroscope or other form of inertial sensor may be incorporated to perform position measurements and further refine the orientation measurements.
In a some embodiments, downhole sensors 26 are coupled to a telemetry transmitter 28 that transmits telemetry signals by modulating the resistance to mud flow in drill string 8 . A telemetry receiver 30 is coupled to the kelly 10 to receive transmitted telemetry signals. Other telemetry transmission techniques are well known and may be used. The receiver 30 communicates the telemetry to a surface installation (not shown) that processes and stores the measurements. The surface installation typically includes a computer system of some kind, e.g. a desktop computer, that may be used to inform the driller of the downhole measurements such as formation resistivity and/or relative position and distance between the drill bit and nearby bed boundaries.
The drill bit 14 is shown penetrating a formation having a series of layered beds 34 dipping at an angle. A first (x,y,z) coordinate system associated with the sensors 26 is shown, and a second coordinate system (x″,y″,z″) associated with the beds 32 is shown. The bed coordinate system has the z″ axis perpendicular to the bedding plane, has the y″ axis in a horizontal plane, and has the x″ axis pointing “downhill”. The angle between the z-axes of the two coordinate systems is referred to as the “dip” and is shown in FIG. 1 as the angle β.
Referring now to FIG. 2 , an illustrative resistivity tool 102 is shown. The subassembly 102 is provided with one or more regions 106 of reduced diameter. A wire coil 104 is placed in the region 106 and spaced away from the surface of 102 by a constant distance. To mechanically support and protect the coil 104 , a non-conductive filler material (not shown) such as epoxy, rubber, fiberglass, or ceramics may be used in the reduced diameter regions 106 . The transmitter and receiver coils may comprise as little as one loop of wire, although more loops may provide additional signal power. The distance between the coils and the tool surface is preferably in the range from 1/16 inch to ¾ inch, but may be larger.
Coils 104 and 116 are coaxial with tool 102 , meaning that the axes of coils 104 and 116 coincide with the tool axis. The illustrated tool 102 further includes a first angled recess 108 having a tilted coil antenna 110 , and a second angled recess 112 having a second tilted coil antenna 114 . The term “tilted” indicates that the plane of the coil is not perpendicular to the tool axis. FIG. 3 shows an antenna that lies within a plane having a normal vector at an angle of θ with the tool axis and at an azimuth of a with respect to the tool face scribe line. When θ equals zero, the antenna is said to be coaxial, and when θ is greater than zero the antenna is said to be tilted.
In some contemplated embodiments, coils 104 and 116 are used as transmitter antennas, and coils 110 and 114 are used as receiving antennas. However, one of ordinary skill in the art will recognize that the transmitting and receiving roles may be readily interchanged. Moreover, in some alternative embodiments, coils 104 and 116 may be tilted while coils 110 and 114 are coaxial. In operation, a transmitter coil 104 transmits an interrogating electromagnetic signal which propagates through the well bore and into the surrounding formation. Signals from the formation reach receiver coils 110 , 114 , inducing a signal voltage that is detected and measured to determine an amplitude attenuation and phase shift between coils 110 and 112 . The measurement is repeated using transmitter 116 . From the measured attenuation and phase shifts, the resistivity of the formation can be estimated using conventional techniques.
In the illustrated embodiment of FIG. 2 , the receiver coils are tilted with a 45° angle between the normal and the tool axis. Angles other than 45° may be employed, and in some contemplated embodiments, the receiver coils are tilted at unequal angles or are tilted in different azimuthal directions. In many cases, the tool 102 will rotate during the drilling (and logging) process, so that resistivity measurements can be made with the tilted coils oriented in different azimuthal directions. These measurements may be correlated with tool orientation measurements to enable detection of boundary distances and directions. In other embodiments, virtual antenna steering may be used to synthesize a measurement from any desired antenna orientation given measurements from a sufficiently diverse set of fixed antennas. Further details on virtual antenna steering are available in U.S. Pat. No. 6,181,138, “Directional resistivity measurements for azimuthal proximity detection of bed boundaries,” to T. Hagiwara and H. Song.
As suggested in U.S. Pat. No. 7,138,803, “Electromagnetic Wave Resistivity Tool Having a Tilted Antenna for Geosteering within a Desired Payzone,” to Michael Bittar, the receivers of tool 102 have azimuthal sensitivities in opposite directions when receiving from the different transmitters. The phase differences in response to the first and second transmitters can be expressed as:
δ T1 (γ)=Φ R1T1 (γ)−Φ R2T1 (γ) (1)
δ T2 (γ)=Φ R2T2 (γ)−Φ R1T2 (γ) (2)
where, e.g., Φ R2T1 represents the phase of Receiver 2 's voltage signal in response to the signal sent by Transmitter 1 , and angle γ is the rotational orientation of the tool. Apart from a longitudinal shift in tool position,
δ T2 (γ)≅δ T1 (γ+180°). (3)
This observation will be helpful to the understanding relationships between the various alternative bed boundary indicators below.
FIG. 4 shows a flowchart of an illustrative method for generating a resistivity log using the tool of FIG. 2 . This method may be performed by a processor in the tool alone or in cooperation with a surface computing facility. Beginning in block 405 , the tool's position is determined. This position determination may include tool orientation and eccentricity, but at a minimum it includes a determination of the tool's depth or position along the length of the borehole so as to permit later correlation with independent measurements of formation properties from other sources. In block 410 , the first transmitter transmits an electromagnetic signal, which propagates through the formation and induces a voltage signal in each of the two receivers. The received signals may be combined to determine an amplitude ratio (attenuation) and a phase difference in the electromagnetic fields at the receiver positions. In block 415 , a similar attenuation and phase difference is measured with respect to the second transmitter. The measurements of blocks 410 and 415 are preferably performed quickly enough so that tool motion during and between the two measurements is negligible or easily compensable.
In block 420 , a bed boundary indicator is calculated from the attenuation and/or phase measurements of blocks 410 and 415 . The bed boundary indicator is a signal having a magnitude that is near zero for distant boundaries and grows larger for nearby boundaries. The polarity of the bed boundary indicator may be indicative of whether the boundary is with a bed of higher or lower resistivity than the current bed. The bed boundary indicators described hereafter are derived from observations in opposite azimuthal directions. One bed boundary indicator is:
I (γ)=δ T1 (γ)−δ T1 (γ+180°). (4)
Equations (3) and (4) can be combined to create an alternative bed boundary indicator:
I (γ)=δ T1 (γ)−δ T2 (γ). (5)
Or, rather than simply comparing in opposite directions, an integral or average may be used as a baseline for determining the indicator:
I ( γ ) = δ T 1 ( γ ) - 1 2 π ∫ - π π [ δ T 1 ( γ ) ] ⅆ γ , or ( 6 ) I ( γ ) = δ T 2 ( γ - π ) - 1 2 π ∫ - π π [ δ T 2 ( γ ) ] ⅆ γ , ( 7 )
where γ is now expressed in radians. As yet another alternative, equations (6) and (7) may be averaged or added together (after accounting for the longitudinal shift):
I ( γ ) = [ δ T 1 ( γ ) + δ T 2 ( γ - π ) ] - 1 2 π ∫ - π π [ δ T 1 ( γ ) + δ T 2 ( γ ) ] ⅆ γ . ( 8 )
A potential advantage of using measurements from both transmitter antennas (and accounting for the appropriate longitudinal shift) is that the inherent errors of the phase measurement circuitry (perhaps due to thermal drift) can be automatically compensated.
The foregoing bed boundary indicators have been based on the measured phase shift. An alternative basis for the bed boundary indicators is the attenuation:
δ T1 (γ)=ln( A R1T1 (γ))−ln( A R2T1 (γ)) (9)
δ T2 (γ)=ln( A R2T2 (γ))−ln( A R1T2 (γ)) (10)
where, e.g., A R1T2 represents the amplitude of Receiver 1 's voltage signal in response to the signal sent by Transmitter 2 . The foregoing bed boundary indicator equations (4)-(8) can be based on the values taken from equations (9) and (10).
Monotonic functions of the phase and/or attenuation can also be incorporated into the bed boundary indicator calculations without departing from the scope and spirit of the claims. One particularly suitable example of a monotonic function is the formation resistivity that the tool is designed to calculate. FIG. 7 illustrates one possible resistivity function, though in practice other parameters may be included in the resistivity determination to account for formation dip, borehole size, tool eccentricity, etc. Representing the monotonic (e.g., resistivity) function by R(.), equations (4)-(8) become:
I
(
γ
)
=
R
(
δ
T
1
(
γ
)
)
-
R
(
δ
T
1
(
γ
+
180
°
)
)
.
(
11
)
I
(
γ
)
=
R
(
δ
T
1
(
γ
)
)
-
R
(
δ
T
1
(
γ
)
)
.
(
12
)
I
(
γ
)
=
R
(
δ
T
1
(
γ
)
)
-
1
2
π
∫
-
π
π
[
R
(
δ
T
1
(
γ
)
)
]
ⅆ
γ
,
or
(
13
)
I
(
γ
)
=
R
(
δ
T
2
(
γ
-
π
)
)
-
1
2
π
∫
-
π
π
[
R
(
δ
T
2
(
γ
)
)
]
ⅆ
γ
,
(
14
)
I
(
γ
)
=
[
R
(
δ
T
1
(
γ
)
)
+
R
(
δ
T
2
(
γ
-
π
)
)
]
-
1
2
π
∫
-
π
π
[
R
(
δ
T
1
(
γ
)
)
+
R
(
δ
T
2
(
γ
)
)
]
ⅆ
γ
.
(
15
)
In block 425 ( FIG. 4 ), a compensated phase difference is determined. The compensated phase difference is the average of the phase differences in response to the first and second transmitters (with an appropriate longitudinal position shift to align the centers of each transmitter-receiver arrangement):
δ C = 1 2 π ∫ - π π [ δ T 1 ( γ ) + δ T 2 ( γ ) ] / 2 ⅆ γ ( 16 )
The compensated phase difference (or compensated attenuation measurement) offers a more symmetric response to formation beds than do the individual measurements in response to the first and second transmitters. FIG. 5 shows an illustrative log of compensated phase difference 502 as a function of depth for a model formation. The model formation has a fifty-foot thick bed with a resistivity of 50 Ωm between underlying and overlying beds having a resistivity of 1 Ωm. Note that the compensated phase difference 502 exhibits “horns”, i.e., overshoots in the measurement at the bed boundaries. These artifacts in the response may appear to indicate the presence of additional beds where in fact they do not exist.
In block 430 , the compensated measurement is processed to remove the artifacts. In some embodiments, the processing includes adding a function of the bed boundary indicator to suppress the horns, e.g.:
δ P = δ C + k · 1 2 π ∫ - π π I ( γ ) ⅆ γ ( 17 )
where k is chosen to provide optimal removal of the horns. In some embodiments, k=−½. The compensation can alternatively be done in the resistivity domain:
R
(
δ
P
)
=
R
(
δ
C
)
+
k
·
1
2
π
∫
-
π
π
I
(
γ
)
ⅆ
γ
(
18
)
In block 432 , the processed phase difference δ P (or the resistivity determined from the processed phase difference, R(δ P )) is plotted as a function of tool position. As additional measurements are made, processed, and plotted, the user is provided with a formation resistivity log. In block 434 , a check is made to determine if additional measurements are available. If so, the process repeats, beginning with block 405 .
The foregoing method has been described as a simple sequence of actions for illustrative purposes. In practice, various method actions may be performed concurrently and independently by different tool components. In some embodiments, transmitters of different frequencies may be used to enable simultaneous measurements using both transmitters.
As mentioned above, FIG. 5 shows an illustrative log of the compensated phase difference 502 , as calculated from equation (5) for a fifty-foot bed of 50 Ωm resistivity. A log of the bed boundary indicator 504 as calculated from equation (5) is also shown. Finally, there is shown a log of the processed phase difference 506 that results from the calculation of equation (17). A comparison of logs 502 and 506 reveal that the disclosed processing method nearly eliminates the horns from the response.
FIG. 6 shows two illustrative resistivity logs. The first log of resistivity 602 is calculated from the compensated phase difference log 502 , while the second log of resistivity 604 is calculated from the processed phase difference log 506 . A comparison of the resistivity logs reveals that a substantial improvement in accuracy results from the processing method described in FIG. 4 . Preferably, the compensate resistivity or phase difference log ###
In some system embodiments, the azimuthally-directed resistivity R(γ) logs are used alone or in conjunction with the bed boundary indicator I(γ) to determine distance and direction to nearby bed boundaries. In some cases, it is possible to estimate the formation resistivity on the far side of the boundary.
While the present invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. For example, the bed boundary indicator signal may be derived from a different set of transmitter and/or receiver antennas than the resistivity signal. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention. | Systems and methods are disclosed for reducing boundary-related artifacts in logs taken from resistivity logging tools. Such tools often exhibit “horns” at boundaries between formation beds having different resistivities. A boundary indicator signal serves to identify the location of these boundaries. When derived from an azimuthally-sensitive resistivity tool, the bed boundary indicator may have a magnitude and shape that serves to nearly eliminate the horns even in high-dip angle environments. Logs that are processed to eliminate these artifacts are expected to be more accurate and thus easier to interpret. | 4 |
FIELD OF THE INVENTION
[0001] This invention relates to the field of biotechnology and genetic engineering, and particularly to the expression of recombinant peptides. The inoculation of these in cattle results in the production of an immune response capable of adversely affecting Rhipicephalus microplus ticks, which feed on the inoculated cattle, decreasing the number and reproductive capacity of this tick species. Such recombinant immunogen can be used as an effective vaccine for tick control.
[0002] The first object of this patent application is related to two nucleotide sequences encoding two recombinant peptides. The second object of this patent application is related to the amino acids sequences that comprise the recombinant peptide. The third object of this application is related to two different presentations of a recombinant peptides based vaccine against ticks, containing the recombinant peptides produced in Pichia pastoris , saponin added as adjuvant. The nucleotide sequences, recombinant peptides, and vaccines described herein may be used in the immunization of animals in cattle parasite tick control programs, and represent alternatives to vaccines available on the market. These products mentioned above may be used in pharmaceutical industries or animal health field.
STATE OF PRIOR ART
[0003] The common tick of cattle, belonging to the Ixodidae family, is the main ectoparasite of cattle in Brazil and in all tropical and subtropical countries. It is an extremely well-adapted parasite to the climate conditions of most part of the country, and together with the presence of their hosts distributed in more than 90% of the country, it is a problem of major proportions to Brazilian cattle. The associated losses are not limited only to the production drop due to the intense haematophagy but also to other damages such as the effect of parasite saliva in the bovine immune system, leather depreciation, influence on the production capacity of animals and, especially, transmission of several microorganisms that cause diseases of importance in national livestock such as Babesia bovis and Babesia bigemina, with participation in the epidemiology of anaplasmosis caused by Anaplasma marginate.
[0004] The direct damage caused by the intense haematophagy conducted, mainly, by females, reaching an amount of 0.6 to 3 mL per teleoginae (ARTHUR, Ticks and disease London: Pergamon Press, 1961. 150p), reflects on production loss. HOLROYD et al., (Australian Journal Experimental Agriculture 28: p. 1-10, 1987) observed that animals that did not have contact with ticks had gains averaged over 17 kg in three years, when compared to those who were exposed to the parasite. In Brazil, BRANCO et al., (Coletânea de Pesquisa EMBRAPA), p. 229-234, 1987) found average weight gain of 34.5 Kg in cattle of Hereford breed. In 1996 FURLONG et al., (XV CONGRESSO PANAMERICANO DE CIÊNCIAS VETERINÁRIAS. Campo Grande PRCA: p. 340) observed a small decline in milk production in growing and successive infestations. JONSSON et al., (Veterinary Parasitology 78: 65-77, 1998), in Australia, estimated that each teleoginae (adult female) would be responsible for the daily production loss of 8.9 mL of milk and 1.0 g of body weight.
[0005] It should also be count as losses to Brazilian cattle expenditures related to the direct control of the ticks and the diseases transmitted by it. HORN and ARTECHE (A Hora Veterinária. 4:12-32, 1985) estimated in 800 million dollars the direct and indirect losses. The Ministry of Agriculture, in work done in the biennium 1983/1984, raises this value to US$1 billion figure, being that 40% of this amount is related to losses in milk production.
[0006] Taking into account the data calculated in 1985 Grissi et al., (A Hora veteranária. 21:8-10, 2002) updated the caused losses coming to the figure of US$2 billion year; of course this calculation includes direct and indirect damages, including transmitted diseases. Therefore, what could be called the complex Rhipicephalus microplus /hematozoa, would give an average annual loss of US$11.76 per bovine. Currently, the cattle population in the country is estimated at 200 million head, which theoretically would reach R$2.3 billion annually.
[0007] The control method most used worldwide is the chemical, based on acaricides (pesticides) of different bases. However, implications of various orders have been noted, especially the development of resistance by ticks by the active ingredients employed. Moreover, the constant use of these products, given the resistance, has led to contamination of ecosystems and to the presence of waste in food derived from animal origin. Thinking on foreign meat and milk market, it must undergo sanitary barriers on residues in meat and milk, and derivatives thereof. Recently, occurred the embargo of tons of meat products by macrocyclic lactones waste used as endectocides.
[0008] In Brazil, according to FREIRE (Boletim da Direção de Produção Anual. 9:3-31, 1953), the resistance to arsenic was first documented in 1950. This same researcher (Boletim da Direção de Produção Anual. 13:62-80, 1956) reported the first cases of resistance to chlorinated compounds occurring in Rio Grande do Sul estate. The resistance to organophosphates in Brazil was described by SHAW et al., (Journal Economic Entomology 61:1590-1594, 1968); AMARAL et al., (Journal Economic Entomology 67:387-389. 1974): WHARTON (Wild Animal Review. 20:8-15, 1976); PATARROYO AND COSTA (Tropical Health Animal Production 12:6-10, 1980) and Oliveira et al., (Arquivos Brasileiros de Medicina Veteranária e Zootecnia. 38:205-214, 1986). FLAUSINO et al., (Revista Brasileira de Parasitologia Veterinária. 4:45, supplement 1, 1995), working in the state of Rio de Janeiro, showed the resistance factors regarding the LD50 for the chemical base amitraz as 50.7 and ranging from 8.5 to 20.9 regarding alphamethrin pyrethroids, deltamethrin and lambda (λ) cyhalothrin. The same researchers in the country's northeast region, and specifically in the state of Pernambuco, found resistance to compounds, which have amidine as chemical basis and to the synthetic pyrethroids cypermetrina and deltamethrin. MARTINS E FURLONG (Veterinary Record 149:64, 2001) studying Brazilian samples of R. microplus , found resistance to moxidectin, doramectin and ivermectin, which indicantes the emergence of cross-resistance to the chemical group of avermectins. Such publications show that all chemical bases existing in the market has caused resistance in populations of this parasite, being necessary to increase the dosage of the product or to increase the frequency in the treatment, increasing the contamination.
[0009] Worldwide, there are several lines of research for alternative methods for R. microplus tick control. Alternative control measures are proposed as a way of minimize obstacles arising from the use of chemical fungicidal, which, in addition to resistance, bring waste problems for animal products and to the environment.
[0010] Among these alternative measures, it can be highlighted the use of pastures, or the rotational use of them, which hinder larvae access or that release volatile agents (LABRUNA and VERÍSSIMO, Arquivos Instituto Biológico 68:115-120, 2001; RUVALCABA FERNANDEZ et al., Experimental and Applied. Acarology. 32: 293-299, 2004). Another measure that has been addressed is the bath of animals with herbal extracts that inhibit the larvae access (Heimerdinger et al., Journal of Veterinary Parasitology. 15:37-39, 200; BROGLIO-MICHELETTI et al., Revista Brasileira de Parasitologia Veterinária. 18:44-48, 2009). The entomoparasitas employment is another technique under evaluation. Among the entomoparasitas, it can be highlighted the Megaselia scalaris fly which reduces the number of eggs of teleoginae (ANDREOTTI, Embrapa Gado de Corte, Didactic Article 2002). Entomopathogenic nematodes are promising biological agents in the control of several tick species, including R. microplus , destroying the hemocele of these species (Samish and Glazer, Trends Parasitology. 17:368-371, 2001; Vasconcelos et al., Parasitology Research. 94:201-206, 2004).
[0011] The animal breeding in the selection of more resistant strains to tick is still a controversial process. There is controversy over estimates of heritability values and it has been questioned the correlation between the tick resistance trait and the animal productivity (JONSSON et al., Veterinary Parasitology, 89:297-305, 2000; FRISCH et al., International Journal for Parasitology. 30:253-264, 2000). What is known is that cattle with higher levels of zebu blood ( Bos indicus ) have greater resistance to parasites, and, even within this group, there are races differences. The Nellore cattle, for example, are more resistant than the Gir or Guzerá (Verissimo et al., Arquivos do Instituto Biólogico. 71:630-632, 2004; JONSSON, Veterinary Parasitology. 137:1-10, 2006).
[0012] Despite ongoing research concerning non-polluting and non-chemical alternatives to tick control, yet very little is known about the ecological interactions and the impact that the introduction of alien species, whether vertebrate or invertebrate, cause the environment. Pending a final solution in this field, the alternative left to the producer is still the use of acaricide drugs, however the problems of their employment, briefly reported previously, lead to a reality that urges the discovery and development of an fighting alternative to this parasite.
[0013] Research and scientific advances in immunology, as the growing understanding of biology of parasites, use of modern tools such as molecular biology, and high production scale allow antiparasitic vaccines to be a great possibility (DALTON and MULCAHY, Veterinary Parasitology.98: 149-167 2001). The development of vaccines against ticks is a clear alternative of control.
[0014] The identification of protective antigens for bovine against R. microplus is increasing, regarded the economic impact and the difficulties already mentioned, in the control of this parasite.
[0015] In 1994, in Australia, it was released the first commercial vaccine against R. microplus using the gene bm86 cloning in Escherichia coli and the production of the recombinant protein Bm86 (rBm 86), given the name TickGARD® (Hoechst Animal Health, Australia), and subsequently named TickGARD Plus® (Smith et al., The development of TickGard a commercial vaccine against the cattle tick Boophilus microplus . Indooroopilly: Biotec Autralia-CSIRO, 17 p. 1995; Willadsen, Veterinary Parasitology. 71:209-222 1997). With the bases of the same antigen, the vaccine Gavac® was formulated in Cuba (Heber Biotec S.A., Havana, Cuba) and Gavac Plus®, but this rBm 86 was produced in Pichia pastoris (GARCÍA-GARCÍA et al., Vaccine 16:1053-1055, 1998).
[0016] The efficacy of these vaccines has varied between 50 and 91%. These values are evaluated by viability reduction and the number of eggs, consequently reducing the number of ticks in subsequent generations, having committed all the development stages
[0017] (RODRIGUEZ et al., Journal of Biotechnology 33:135-143, 1994; JONSSON et. al, Veterinary Parasitology. 88:275-285, 2000).
[0018] Some samples of R. microplus , however, were less susceptible to the recombinant vaccine Bm86 (rBm86). The inefficiency was determined in an Argentine population later named as strain A, which showed that it had a different gene, the bm95 gene, which was then cloned and expressed in P. pastoris yeast and used as another recombinant vaccine controlling the population that was resistant to rBm86 (Garcia-Garcia et al., Vaccine. 18:2275-2287, 2000).
[0019] The geographic isolation of R. microplus strains can lead to these genetic and physiological differences, referring to a negative response to the control by vaccination (GARCÍA-GARCÍA et al., Experimental and Aplied Acarology. 23:883-895 1999). Thus, there is a constant search for an immunogen, or combination of antigens, that covers the largest possible number of populations, protecting the flock from infestations by R. microplus.
[0020] The patent document WO2012041260 deals with the control of ectoparasites and transmitted diseases. They are several sequences of ribosomal proteins (POs) that form chimeras with different proteins. With respect to ticks, and specifically to R. microplus , the full-length protein called Bm86 was used as an antigen eliminating the gene fragments of the signal peptide and the transmembrane region to construct a chimeric protein (Bm86-pPO). It was inoculated in cattle using the Montanide as an adjuvant. It has no similarity to the current application for patenting because it is not the recombinant peptide and the claims have no similarity to our demands.
[0021] In the patent document WO2009127766, are used peptides of the protein called Bm95 of the R. microplus to be fused to the N-terminal region of the surface protein called MSPla of Anaplasma marginate. It is not similar to this application, it is not a recombinant peptide expressed by transfection of synthetic genes in yeast for the bovine common tick control, the R. microplus.
[0022] The patent document ZA9901320 is related to the biotechnology field of vaccines, i.e. to the development of peptide vaccines (Mimotopes) to control the cattle tick. Said vaccine has potential application due to the fact that the tick proteins are recognized by sera from mice inoculated with the peptide fused-phages that express, and also by the fact that teleoginae ticks had a blackish color suggesting hemorrhagic damage in challenge tests. Given that, there is a great need for new methods for controlling Rhipicephalus microplus , a potential vaccine can be developed using isolated peptides, together or associate with existing antigen, for effective control of tick. For the above, it was used the technique of phage display, which is very wide and selects many possible peptides with the possibility of being used because is a mapping. Said process consists of repeated cycles of selection, the eluted wash, and the amplification of filamentous phage, which express the random peptide sequences that bind with affinity for several molecules, including immunoglobulins. It has no similarity to our request for patenting because it is not a single recombinant peptide expressed by transfection of synthetic genes with proven action to control R. microplus on cattle.
[0023] The Patent document CA1339466 of tick vaccine, specifically of R. microplus , refers to the gene encoding the protein named Bm86, which is composed by 650 amino acids. The protein can be found in natural state in such tick and has not undergone any change because it is the protein found naturally in the parasite. It is not similar to the current application due to it is a full length protein and is different from this request because it refers to a recombinant peptide produced by transfection of synthetic genes in P. pastoris yeast strain KM71.
[0024] The patent document PI 0001717-5, AU 779 537, MX 270 574, EN 1289545, ES 236043, US 8,110,202 present a synthetic vaccine for the control of Rhipicephalus ( B. ) microplus . It has been shown that the developed vaccine elicits a complete immune response to any antigen complex. It is interesting to note that the vaccine stimulates a T-dependent immune response. (Patarroyo et al., Veterinary Parasitology 166:333-339, 2009).
[0025] Genetic variability studies analyzing 20 samples of different places and geographical conditions of Brazilian regions, and other South American countries, have shown that the patented sequence SBm7462 remained conserved among all populations (SOSSAI et al., Experimental and Applied Acarology 37:199-214 2005; PECONICK et al., Experimental Parasitology 119:37-43, 2008), concluding that there is not variability in these sequences that may interfere with the vaccine efficiency. This reinforced the concept of universal antigen or immunogen. It also means that the antigenic determinants of the developed vaccine are present in all studied populations.
[0026] The SBm7462 synthetic vaccine controls efficiently R. microplus , however it presents limitations for producing the synthetic peptide in large scales.
[0027] Taking into account the needs to control the parasite and the efficiency of the developed immunogen SBm7462, it is needed an alternative mean to produce the same. Thus, a new way of producing the same was developed from the fermentation by transfection of synthetic genes of yeast that would encode the synthetic peptide.
[0028] Through recombinant DNA techniques, the vaccine can be produced more efficiently (lower cost, shorter time and large-scale production) being effective for Brazil ticks, as well as develop a non-toxic product, without waste, and which does not impact adversely the environment.
[0029] The action of the vaccine upon application to the herd works as follows: the proteins are inoculated in cattle and they induce the reaction of the body defense system, which creates specific antibodies against the protein. Parasitizing the vaccinated animal, the ticks suck the blood containing antibodies against its own intestinal cells. The result is an intestinal destruction, which kills the ticks or, at least, reduces their ability to adequately feed and reproduce.
[0030] When applying the vaccine antigens, the cattle develop a protective immunity against ticks, which will prevent many direct and indirect damages that may be caused by this mite. The vaccines based on recombinant antigens do not present a health risk, are safe for the environment, and the development of resistance by ticks through selective adaptation is unlikely (NUTTALL et al., Parasite Immunology. 28:155-163 2006).
[0031] Among the advantages of using this vaccine, to the detriment of acaricide, it can be highlighted: no grace period after application, since it does not leave residues in food, crucial factor in milk cattle; more sustainable action, they are environmentally friendly, since they are nontoxic to the animal, to the environment, and to humans; do not destroy the natural microflora, because it is species-specific will only reach the ticks of the species R. ( B. ) microplus without attacking natural microorganisms inherent in the cattle; and development of resistance by ticks by selective adaptation is unlikely.
[0032] The developed recombinant DNA vaccine is suitable for ticks R. ( B. ) microplus found in Brazil and other South American countries. Genetic variability studies analyzing 20 samples of ticks from different places and geographical conditions of Brazilian regions and Argentina, Venezuela, Colombia, and Uruguay confirm the presence of antigenic epitopes in these populations (SOSSAI et al., Experimental and Applied Acarology. 37:199-214, 2005; PECONICK et al., Experimental Parasitology 119:37-43, 2008).
[0033] The vaccine developed is a herd vaccine in which vaccinating the herd for three annual cycles decreases the tick population, which leads to minimizing the above-mentioned losses and avoid the use of 19 or 20 Acaricide, as it is currently being done in many farms of the country.
[0034] This invention has high social and environmental impact because, currently, there is the need to meet consumer demands for food free of chemicals, protection of the environment, and, consequently, the wild animals. Thus, in a market where the products to combat ectoparasites are mainly chemicals, it is necessary to invest in research and manufacture of alternative products for the control of these agents.
[0035] The vaccines are safe, have a good interface with the environment, and are more readily accepted by consumers, perhaps by the familiarity they have with the vaccine used in human medicine. With its use, there is a greater production and animal productivity increasing than the use of other medications.
[0036] The vaccine, by being subunits (it is not a full length protein) and immunologically defined, do not contain remains of organisms different to the amino acid sequence comprising the recombinant peptide, making it safe to animals and the environment.
[0037] The development of vaccines to combat ticks, or ectoparasites in general, becomes relevant especially by not leaving residues in animal products (meat and milk) and not harming the environment, because their formulations do not have chemicals compounds such as antibiotics and/or heavy metals, among others.
[0038] Contrary to the vaccines, the chemicals used today for combating ticks are highly toxic. If cattle are treated with acaricide and the grace period is not respected, meat and milk should not be intended for human consumption because they are subject to the risk of poisoning, which, for prolonged periods, can lead to harmful effects on human being.
DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 —Kinetics of antibodies in animals immunized with SEQ ID NO. 3. The arrows indicate inoculation and the star the time of challenge with larvae of Rhipicephalus ( B. ) microplus . The T bars indicate the difference by the adding of a standard deviation.
[0040] FIG. 2 —Kinetics of antibodies in animals immunized with SEQ ID NO. 4. The arrows indicate inoculation and the star the time of challenge with larvae of Rhipicephalus ( B. ) microplus . The T bars indicate the difference by the adding of a standard deviation.
DETAILED DESCRIPTION OF THE INVENTION
Obtaining Encoding Sequences
[0041] Two genes called seq1 (SEQ ID NO: 1) and seq4 (SEQ ID NO: 2) were designed from the reverse vaccinology methodology using as base the synthetic peptide on the SBm7462 for use in P. pastoris yeast km71. The seq4 gene was constructed in order to express a similar copy of SBm7462. However, the seq1 gene was designed to express the peptide repeated three times in tandem. The genes were designed with preferred codons for P. pastoris . For the genes drawings, the cloning sites of the expression vector used were taken into consideration. The vector used has an insertion region of heterologous fragments composed of several restriction sites for enzymes called (XhoI, SnaBI, EcoRI, AvrII and NotI).
[0000] Construction of Expression Cassettes seq1 (SEQ ID NO: 1) and seq4 (SEQ ID NO: 2)
[0042] The sequences corresponding to the genes were cloned into the pPIC9 vector, which was subjected to cleavage with appropriate restriction enzymes. Through these divisions, sticky ends were formed on both vectors and genes, allowing the connection of the genes in the correct ORFs (Open Reading Frame) in their respective expression vectors. All cleavage reactions were analyzed by agarose gel electrophoresis 0.8%. The construction of the cassettes were given through the use of the enzyme T 4 DNA ligase, whose function was to catalyze the bonding of the cohesive ends of the strands 5′-3′ of the vector with the 3′-5′ of the gene and vice versa.
Analyses of the Expression Cassettes by Colony PCR and Sequencing.
[0043] The constructed expression cassettes were multiplied in E. coli DH5a. Clones of each gene were analyzed by colony PCR and subsequently sequenced in order to verify the correct presence of the gene in the expression cassette.
[0044] The clones confirmed by sequencing were subjected to growth in LB liquid medium at 37° C., under 250 rpm orbital shaking for 16 hours for subsequent extraction of the expression cassettes that were used to transform the yeast Pichia pastoris KM71.
[0000] Preparations of Cassettes seq1 (SEQ ID NO: 1) and seq4 (SEQ ID NO: 2) for Electroporation.
[0045] For the transformation of P. pastoris km71 by electroporation, the expression cassettes were linearized with restriction enzyme Scl (WU and LETCHWORTH, Drug Discovery and Genomic Technologies, 36:152-154, 2004).
[0046] In each cleavage reaction, it was used approximately 20 μg of plasmid DNA in excess of three times the enzyme at 37° C. and overnight.
[0047] The monitoring of the cleavage was carried out before the end of the reaction by gel electrophoresis in 1% agarose, stained with ethidium bromide, and visualization under UV light. After verification of the total linearization of the expression cassettes, the entire reaction was applied in adjacent channels on 0.8% agarose gel and subjected to electrophoresis. The extraction of the bands containing the linearized plasmid was given using appropriate commercial kit. The extracted material was subsequently precipitated with ethanol in order to concentrate it to 10 μg in 10 uL of nuclease-free water, which was the final volume used in the transformation of the yeast.
[0000] P. pastoris Km71 Yeast Transformations with the Expression Cassettes and Selection in MD Medium.
[0048] The genetic transformation of the yeast P. pastoris km71 occurred by electroporation technique. To this, 10 g of each plasmid previously linearized with the restriction enzyme were added to 80 μL of electronically competent cells and transferred to 0.2 cm electroporation cuvettes. The DNA and P. pastoris km71 mixture was kept on ice for 5 minutes to allow thermal equilibration of the solution. After this period, the cuvettes were placed in electroporation cell and subjected to an electrical pulse (1.5 kV, 25 μg, and 200Ω).
[0049] Immediately after electroporation, 1 mL of sorbitol 1M was added in the electroporation chamber and kept in the ice bath for 5 minutes. After this period, 200 μL of the transformants were plated on MD solid medium lacking histidine (YNB 1.34%, biotin 4×10 −5 %, dextrose 2% and bacteriological agar 1.5%). For all transformed clones, plating were made in duplicates. The plates were maintained at 30° C. for 72 hours until complete growth of the clones. The selection with the MD medium is due because only the yeasts transformed with the vector pPIC9 develop due to the presence of the histidinol dehydrogenase gene that synthesizes the amino acid histidine.
[0000] Confirmations of P. pastoris Km71 Clones by Polymerase Chain Reaction (PCR).
[0050] Besides the selection of transformed clones of P. pastoris Km71 by the passage in medium lacking histidine (MD), clones of each gene were subjected to the extraction of total DNA and amplification thereof by PCR.
[0051] The chromosomal DNA of the previously selected clones was extracted from cultures grown in liquid MD under 250 rpm stirring for 48 hours at 30° C. The culture was recovered by centrifugation, for 10 minutes, at 5000 g at room temperature. The pellet was resuspended in 400 μL of extraction solution (Triton 100× 2%, SDS 1%, NaCl 100 mM, Tris-HCl 100 mM and EDTA 10 mM, pH 8.0), and transferred to a 2 mL tube containing 300 mg of glass beads of 0.45 mm in diameter used for mechanical lysis of the yeast through orbital shaking vigorously for 2 minutes. Subsequently, 200 μL of phenol and 200 μL of chloroform were added and again proceeded to vigorous shaking for two minutes to enhance lysis of cells and subsequent DNA extraction. After this phase, the solution was centrifuged for 5 minutes at 5000 g. The aqueous phase was transferred to a new tube and treated with RNAse (10 μL of a 10 mg/mL solution) for 1 hour at 37° C. and, right after, with proteinase K (20 μL of a 10 mg/mL solution) for 2 hours at 37° C. The precipitation was performed by adding 1/10 volume of sodium acetate pH 5.2, plus 2 volumes of cold absolute ethyl alcohol. The solution was gently stirred and kept at −20° C. for two hours to increase the yield of DNA precipitation and then centrifuged for 5 minutes at 5000 g. The pellet was washed with 70% ethanol for two successive centrifugations and dried at room temperature. Subsequently, the DNA was re-suspended in 100 μL of nuclease-free water, quantified in agarose gel 1% with lambda DNA, and stored at −20° C. until use.
[0052] To determine the insertions of the genes in yeast chromosome it was used the PCR technique and the primers 5′AOX1 (5′-GACTGGTTCCAATTGACAAGC-3′) and 3′AOX1 (5′-GCAAATGGCATTCTGACATCC-3′).
[0000] Selections of seq1 (SEQ ID NO: 1) and seq4 (SEQ ID NO: 2) Clones by Colony Blotting.
[0053] The P. pastoris Km71 clones preselected through MD and PCR for recombinant expression were selected by protein production analysis by Western Blotting colony. The technique was chosen because the yeasts transformed with the cassette SEQ ID NO: 1 and SEQ ID NO: 2 export the expressed protein into the extracellular medium. For that, clones transformed with SEQ ID NO: 1 and SEQ ID NO: 2 were selected randomly. These two clones were plated on petri dishes containing the solid YPD medium until the colonies reach a mean diameter of 3 mm, in an oven at 30° C. Once reaching the required size with the aid of a nitrocellulose membrane, the clones were collected and transferred by imprint and passed to other two of MM expression medium containing plates (YNB 1.34%, biotin 4×10 −5 %, methanol 0.5% and bacteriological agar 1.5%) with a 0.2 μm nitrocellulose membrane equilibrated in this medium at 30° C. for 12 hours. The imprints were placed in direct contact with the 0.2 μm membranes, taking care to remove all air between the membranes. The plates were incubated at 30° C. for 72 hours, necessary time to have an optimum proteins expression and their transfer to the membrane.
[0054] After the genes induction period, the nitrocellulose membranes were collected so to avoid the drag of the colonies as much as possible. Subsequently, the nitrocellulose membranes were treated with methanol 100% for 1 minute to fix the protein and immediately subjected to 3 successive washings, 20 seconds each, with Milli-Q water.
[0055] The detection of producing clones was performed by enzyme immunoassay dot-blotting. Thereunto, the membranes were blocked with PBST 0.05% pH 7.6 (NaCl 4.25 g; Na 2 HPO 4 0.64 g; NaH 2 PO 4 .H 2 O 0.068 g; Tween-20 0.05% and H 2 O Milli-Q q.s.p. 500 mL) for 30 minutes under side agitation. After this step, the membranes were subjected to three successive washes with PBST 0.05% for 5 minutes each and, then, incubated for two hours with anti-synthetic peptide rabbit serum SBm7462 diluted at 1:100 (positive control) and the other with normal rabbit serum, or not immunized with the synthetic peptide SBm7462, diluted at 1:100 (negative control). Immediately after the incubation, the membranes were again subjected to three washes of 5 minutes each with PBST 0.05% and then incubated with peroxidase labeled protein A diluted at 1:400 for 1 hour.
[0056] The development of the reaction took place after two washes of 5 minutes each with PBST 0.05% and once with PBS pH 7.6. The substrate was formulated with 10 mg of DAB (diaminobenzidine), 10 mL of Tris-HCl 0.05M pH 7.6; 1 mL of NiCl 2 0.3% and 10 μL of H 2 O 2 30%. The solution was stirred together with the membranes until the early appearance of the background on the negative control. At this time, the reaction was stopped by washing the membrane with Milli-Q water.
Stability Evaluation of the Recombinant Clones
[0057] To evaluate the genetic stability of the recombinants, they were transferred to YPD agar (yeast extract 10 g/L, peptone 20 g/L, glucose 20 g/L, bacteriological agar 20 g/L) and incubated at 30° C. until the appearance of isolated colonies. Thereafter, five colonies of each transformant were successively transferred to non-selective complete medium, YPD, with a total of ten passes. Each pass through the plates were incubated at 30° C. for 72 hours. At the end of the fifth passage, the colonies were transferred to selective MD medium lacking histidine and incubated at 30° C. for a further 72 hours.
Production of Peptides in Bench Fermenter
Pre-Inoculum:
[0058] A P. pastoris clone, frozen with glycerol, at a culture-glycerol ratio of 70%/30%, kept in ultrafreezer (−70° C.), is thawed on ice and grown in 500 mL erlernmeyer containing 250 mL of Medium B (Table 1) at 30° C., and orbital agitation of 250 rpm for 2 days. The sterility of the biomass was examined by light microscopy.
[0000]
TABLE 1
Composition of Part B.
Amount used for 1 L
KH 2 PO 4
13
g
(NH 4 ) 2 SO 4
8.75
g
MgSO 4
4.5
g
CaCl 2 •2H 2 O
0.5
g
Yeast extract
2.5
g
Glycerol
40
mL
pH 5.0. Must be autoclaved.
Fermentation:
[0059] The production of recombinant antigen on a laboratory scale is carried out by fermentative processes in a bioreactor. To the pre-inoculum, 21 mL of PTM1 Trace Salts (Table 2) and 1 mL of antifoam are added. This mixture is placed in a sterile flask with cannula adapted to the bioreactor and added to the 4.5 L of sterile medium B already in the reactor through positive pressure. The reactor is then turned on and the parameters are maintained constant: 2 mmHg oxygen continuous injection, 600 rpm rotation and water jacket maintained at 30° C. The pH is maintained between 5 and 5.5, adjusted with ammonium hydroxide 50% or phosphoric acid 50% diluted in autoclaved water. The buffer are kept in separate flasks connected to the peristaltic pump, which is programmed for automatic pH correction.
[0000]
TABLE 2
Composition of PTM1* Medium.
Amount used for 1 L
CuSO 4 •5H 2 O
6
g
NaI
0.08
g
MnSO 4 •H 2 O
3
g
Na 2 MoO 4 •2H 2 O
0.2
g
Boric Acid
0.02
g
CoCl 2
0.5
g
ZnCl 2
20
g
FeSO 4 •7H 2 O
65
g
Biotin
0.2
g
Sulfuric acid
5
mL
*must be filtered
Feeding
[0060] As the oxygen parameters dissolved in the medium are monitored, and taking into account that the oxygen levels remained low for the consumption, during the biomass growth and multiplication phase, when it rises reaching around 90%, which is approximately 2 days after the start of the fermentation, 400 mL of a sterile solution is added to the medium containing glycerol 50% in water and 6 mL of PTM1/L. After that, dissolved oxygen values should fall again, indicating return to their consumption and multiplication.
Induction
[0061] When all source of carbon provided (glycerol) have been exhausted, the dissolved oxygen parameter will further increase which occurs approximately 3 days after feeding. At this point, begins the induction of the recombinant peptide production with pure methanol, in that a final volume of 400 mL of methanol is added to the culture for 4 days at 1-hour intervals. In the first two hours, a volume of approximately 2 mL is added to the culture adaptation to the new carbon source and, from the 3rd hour, about 4 mL/h, and remains so until the end of the total volume. It is also added separately 1 ml of PTM1 daily.
Purification
[0062] [01] After the induction period, the culture is centrifuged at 4° C. for 15 minutes at 4500 rpm. The supernatant is then subjected to cross-flow filtration, first being clarified in 100 kDa filter, form which the permeable, i.e., the content weight lower than 100 kDa, is collected and subjected to new filtration in 30 kDa filter, where again all permeable is collected. The filtration product is subjected, by the same tangential filtration system, to a dialysis with milli-Q water chilled to 4° C. The sterilization of the product is done by filtration through 0.45 μm membrane and collected in sterile flasks. The sterilization tests are done by inoculating in Sabureau medium and blood agar maintained in bacteriological greenhouse at 37° C. for 96 hours.
[0063] Subsequently, the protein is measured to quantify the dose and packaged in polyurethane flasks, and stored under refrigeration at 4° C.
[0064] The recombinant peptides identified as SEQ ID NO: 3 and SEQ ID NO: 4, encoded by SEQ ID NO: 1 and SEQ ID NO: 2, respectively, were used as immunogens to the Rhipicephalus ( B. ) microplus tick control.
Demonstration Experiment
Efficiency Evaluation of Recombinant Immunogens SEQ ID NO: 3 and SEQ ID NO: 4
[0065] 20 crossbred male cattle were used (H/Z), blood average 7/8, between 6 and 10 months old, coming from dairy farms in the County of Vicosa, MG estate, and maintained since its birth in the arthropod vectors proof cattle isolation.
[0066] The animals were identified by numbered earrings. The feeding was based on balanced feed and forage (hay) with 17% protein, offered at 8 am and 4 pm and water ad libitum.
[0067] The animals were randomly distributed into four groups of 04 animals each. The inoculations were performed in three doses, subcutaneously, as follows:
First inoculation: day 0 (zero); Second inoculation: day 30; Third inoculation: day 60.
[0071] The inoculation scheme is described below:
Group SEQ ID NO: 3: saponin 1.5 mg added to recombinant peptide 1 mg diluted in 4 mL of sterile Milli-Q water. Group SEQ ID NO: 4: saponin 1.5 mg added to recombinant peptide 2 mg diluted in 4 mL of sterile Milli-Q water. Saponin adjuvant control group: saponin 1.5 mg diluted in 4 mL of sterile Milli-Q water. Control Group: 4 mL of sterile Milli-Q water. Pichia pastoris Group: crude extract of P. pastoris not transfected 2 mg diluted in 4 mL of sterile milli-Q water.
[0077] The inoculated animals were constantly monitored, twice a day, for seven days after inoculation for verification of possible hypersensitivity skin reactions to recombinant peptides and adjuvant; besides the daily visual inspection, hematocrit tests were performed on all animals on the seven days after inoculation to observe some hemolytic effect of the recombinant peptides.
Challenge and Infestation of the Cattle
[0078] After 21 days of the last inoculation of the recombinant peptides, all animals were challenged with larvae of R. ( B. ) microplus , in the amount of 1,500 larvae per day for three days, beginning in the morning.
Day 1—breast and dewlap regions Day 2—scapular and between the forelimbs regions Day 3—scrotal and inguinal regions
[0082] The animals were kept in halter and tied by the tail for 8 hours in order to correct fixation of the larvae.
Biological Parameters Evaluation of the detached teleoginae_After the challenge with tick larvae, daily observations were performed until the eighteenth day to check the development of the larvae, nymphs, and predict the likely beginning day of the detachment of teleoginae from the animals. At 21 days, with the beginning of the females fall, it was initiated the collecting procedure, manually, for all teleoginae found on the floor of the stalls, in the feeding trough, and in the grid for debris flow. For a more accurate collection, the bay was washed two times a day and, throughout this wash, the resulting material was sieved, and the removed teleoginae ticks were counted and identified.
Number of Teleoginae
[0084] It was recorded the naturally detached teleoginae as well as the trampled.
Weight of Teleoginae
[0085] The female collected were washed in running water and weighed in analytical balance with a precision of 3 decimal places in order to determine the percentage of reduction of their average weight.
Posture Weight
[0086] After weighing, the females collected were individually wrapped and identified, and left in oviposition for two weeks in an oven at 27° C. and 80% relative humidity (OBA Revista da Faculdade de Veterinária e Zootecnia da Universidade de São Paulo 13: 409-420 1976). After the end of posture, the total posture weight of each group was evaluated.
Larva Weight/Eggs Gram Ratio
[0087] From the total eggs, twenty aliquots of 0.5 g (10,000 eggs) per group were separated in centrifuge tubes, making a total of 10 grams of eggs per group. The tubes were stoppered with cotton wool and the eggs incubated for 26 days in a 28° C. greenhouse and 80% relative humidity. Aliquots were taken at more than one day of eggs weighing. To obtain the results, the techniques described above were employed by (MASSARD et al., Revista Brasileira de Medicina Veterinária 17:167-173, 1995).
Formulas for the Biological Parameters Evaluation
[0088] In order to evaluate the effect of immunogens on the biological parameters of the tick, were employed the formulas advocated by DE LA FUENTE (Recombinant Vaccines for the control of cattle tick Habana: ELPOS Scientae, p. 280, 1995) used for vaccine groups and the control groups, as follows:
[0000] DT (%)=100[1−( NTV/NTC )]
[0000] wherein:
[0089] DT (%)—Reduction percentage in the number of teleoginae
[0090] NTV—number of teleoginae for each vaccination group
[0091] NTC—number of teleoginae for control group.
[0000] DR (%)=100[1−( PMTV/PMTC )]
[0000] wherein:
[0092] DR (%)—Reduction percentage in the average weight of teleoginae
[0093] PMTV—Average weight of teleoginae for each vaccine group;
[0094] PMTC—Average weight of teleoginae for control group.
[0000] DO (%)=100[1−( PMOV/PMOC )]
[0000] wherein:
[0095] DO (%)—Reduction percentage of average weight of the eggs.
[0096] PMOV—Average weight of the eggs for each vaccine group.
[0097] PMOC—Average weight of the eggs for control group.
[0000] DF (%)=100[1−( PPLOV/PPLOC )]
[0000] wherein:
[0098] DF (%)—Reduction in the eggs fertility.
[0099] PPLOV—Average weight of larvae per gram of eggs in each vaccine group.
[0100] PPLOC—Average weight of larvae per gram of eggs in the control group.
[0000] EF (%)=100[1−( CRT×CRO×CRF )]
[0000] wherein:
[0101] EF (%)—Immunogen effectiveness.
[0102] CRT—Reduction in the number of adult females (1−DT)
[0103] CRO—Reduction in the oviposition capacity (1−DO)
[0104] CRF—Reduction in fertility (1−DF)
[0105] The values obtained for each vaccine group were statistically analyzed by Tukey test.
Humoral Kinetic Studies
[0106] The blood collection of animals was done weekly from week 0 to week 14, and the first sample was collected before the first inoculation. The serum obtained from each sample was aliquoted into Eppendorf tubes at −20° C. The kinetics were measured using enzyme immunoassay ELISA.
[0107] The Maxisorp® plate were coated with a carbonate buffer solution of pH 9.6 (Na 2 CO 3 0.159 g; NaHCO 3 0.293 g, H 2 O Milli-Q q.s.p. 100 mL), wherein the peptide was diluted in the amount of 2 mg/well, leaving to adsorb at 4° C. overnight. After this period, the plates were washed twice with Wash Buffer solution (NaCl 9.0 g; Tween-20 0.5 mL, H 2 O dd q.s.p. 1000 mL) and added to the blocking solution—Casein 2% in PBS pH 7 6 (NaCl 4.25 g; Na 2 HPO 4 0.64 g; Na 2 HPO 4 .H 2 O 0.068g, H 2 O Milli-Q q.s.p. 500 mL) for one hour at room temperature. The plates were washed twice and thereafter 100 mL/well of the experimental animals sera was added diluted at 1:100 in Incubation Buffer solution (PBS 87.5 mL pH 7.6, 12.5 mL Casein 2% in PBS pH 7.6; Tween 20 50 mL) and allowed to incubate for two hours at room temperature. The plates were washed six times with wash buffer solution and proceeded with incubation for two hours at room temperature, of the secondary antibody—IgG rabbit anti-IgG bovine conjugated to peroxidase, diluted in incubation buffer solution, the volume of 100 mL/well. The plates were washed six times with wash buffer and added to the developing solution at 100 mL/well of volume comprised of Substrate Buffer 20 mL (Na 2 HPO 4 7.19 g, citric acid 5.19 g, and H 2 O Milli-Q q.s.p. 1000 mL), O.P.D. 4 mg (q-phenyldiaminebenzene) and H 2 O 2 2.5 mL, for a period of 20 minutes in the dark. The reaction was stopped with 30 mL/well of sulfuric acid 1:20. The reading was performed on ELISA reader at 492 nm.
[0108] To discriminate the cut point between positive and negative for antibody response measured in ELISA, it was used the addition of two standard deviations from the negative controls.
Statistical Analysis
[0109] It was used the analysis of variance (ANOVA) to compare the various tests. For this, it was found that the data met the assumptions of normality and variance of the samples, and thus, the Tukey test was done.
[0110] All statistical analysis were performed using the statistical software Sigmastat® Version 2006.
Results
[0111] The data set for the biological parameters analyzed after counting and weighing teleoginae, weighing eggs and larvae, as well as the reducing parameters of the number and weight of the teleoginae, the egg weight, fertility and efficiency are shown in Table 3. It can be seen that the number of adult ticks (teleoginae) detached from the control group was higher than in the groups immunized with the recombinant peptides, SEQ ID NO: 3 and SEQ ID NO: 4, showing a lower number unfastened form immunized groups, being the reductions statistically significant when compared to the controls, and, also, statistically different reducing of engorged female ticks from animals immunized with the two recombinant peptides. It may also be observed that the detached teleoginae, both from the control group and the immunized with recombinant peptides obtained from the sequences, showed no statistically significant differences between them with respect to the average weight.
[0112] By analyzing the average weight of the eggs, it was found that there was no statistically significant difference between the different control groups with each other nor compared these with the results for the group of animals immunized with the recombinant peptide SEQ ID NO: 4; however when comparing the results of the various controls with those obtained in the group of animals immunized with the recombinant peptide SEQ ID NO: 3 they were significantly lower showing statistical difference, there were also statistically significant results among groups of animals immunized being the average weight of the eggs lower in the group immunized with the recombinant peptide SEQ ID NO: 3.
[0000]
TABLE 3
Biological parameters of Rhipicephalus (B.) microplus from animals immunized
with the recombinant peptides SEQ ID NO: 4 and SEQ ID NO: 3 and control groups of
P. pastoris , adjuvant control, Milli-Q water control. The different letters (a, b, c)
indicate a statistically significant difference at 0.01% level of significance in Tukey test.
BIOLOGICAL PARAMETERS GROUPS
Pichia
Saponin
Milli-Q
SEQ ID
SEQ ID
Control
Control
Control
NO: 4
NO: 3
Number of teleoginae
1049 a
1046 a
1055 a
362 c
522 b
detached
Average weight of teleoginae
0.2553 a
0.2541 a
0.2558 a
0.2516 a
0.2404 b
detached
Average weight of oviposition
0.1224 a
0.1380 a
0.1290 a
0.1183 a
0.0901 b
Larva weight/gram of eggs
0.0533 a
0.0528 a
0.0557 a
0.0441 b
0.0102 c
Weight of eggs reduction
3.35% a
26.38% b
(OF)
teleoginae reduction (DT)
65.49% a
50.23% b
Fertility reduction (DF)
17.26% a
80.86% b
Effectiveness (EF)
72.56%
92.99 b
[0113] In weighing the ratio larvae/gram eggs, it was observed that there was no statistically significant difference between the different control groups, however when comparing these results with those obtained in groups of animals immunized with the recombinant peptides SEQ ID NO: 4, SEQ ID NO: 3 there was a decrease in weight ratio, with a statistically significant difference; between the groups of animals immunized the ratio was lower in the animals immunized with the recombinant peptide SEQ ID NO: 3 showing statistically significant difference between the groups immunized. When comparing the percentage factors of decreased egg weight, the amount of teleoginae, and the reduced fertility, one concludes that recombinant peptides obtained from the sequences described achieved a significant level of reduction and efficiency. The kinetics of recombinant anti-peptides antibody (IgG) is presented as a typical IgG immune response produced by integrating a protein used as antigen and these results are shown in FIGS. 1 and 2 .
[0114] The recombinant peptides SEQ ID NO: 3 and SEQ ID NO: 4, when inoculated on bovines, do not cause any discomfort or adverse reaction in the inoculated animals.
CONCLUSION
[0115] A vaccine for Rhipicephalus ( B. ) microplus tick control based on recombinant peptides obtained from the sequences described has advantages because the developed vaccine is a flock vaccine in which the vaccination of the herd for three annual cycles decreases the tick population, which leads to minimization of losses already mentioned, and avoid the use of 19 or 20 baths of acaricide as it is currently being done in many farms of the country.
[0116] This invention has high social and environmental impact because currently there is the need to meet consumer demands for food free of chemicals, protection of the environment, and consequently the wild animals. Thus, in a market where the products to combat ectoparasites are mainly chemicals, it is necessary to invest in research and manufacture of alternative products for the control of these agents.
[0117] The vaccines are safe, have a good interface with the environment, and are more readily accepted by consumers, perhaps by the familiarity they have with the vaccine used in human medicine. With its use, there is a greater increase in animal production and productivity than with the use of other medications.
[0118] Unlike vaccines, the chemicals used today for combating ticks are highly toxic. If the cattle is treated with acaricide and the grace period is not respected, meat and milk should not be intended for human consumption because they are subject to the risk of poisoning, which, for prolonged periods, can lead to harmful effects on human being.
[0119] The production method of recombinant peptides used as vaccine is easier to industrial level, allows complete reproducibility on a large scale, and is more economical for low-cost production at the industrial level. | The present invention relates to the field of biotechnology and genetic engineering, and particularly to the expression of recombinant peptides. The inoculation thereof in cattle results in the production of an immune response capable of adversely affecting Rhipicephalus microplus ticks, which feed on the inoculated cattle, decreasing the number and reproductive capacity of this tick species. Such recombinant immunogen can be used as an effective vaccine for tick control. The technical goal is the design and construction of two synthetic genes made with preferred codons for Pichia pastoris and expression thereof from a recombinant peptide, which consists in a continuous sequence and of a recombinant peptide, respectively, and the drug composition based of said recombinant polypeptide. | 0 |
RELATED APPLICATION
[0001] This application claims the benefit of priority under 35 U.S.C. §119(e) to U.S. Provisional Application Serial No. 60/249,465 filed on Nov. 20, 2000, which is herein incorporated in its entirety by reference.
FIELD OF INVENTION
[0002] The present invention relates to derivatives and analogues of adenine, which inhibit adenylyl cyclase activity, and are thus useful to treat congestive heart failure. Additionally, the compounds of the present invention are useful to inhibit or prevent a patient's fibroproliferative vasculopathy following vascular injury or a vascular surgical operation. The method according to the invention includes administering to the patient an effective amount of a compound according to the inventions subsequent to the diagnosis of congestive heart failure, the occurrence of a vascular injury, or subsequent to a vascular surgical operation. Administration of the compounds of the present invention is continued either chronically after diagnosis of congestive heart failure or for one to two weeks after the injury or surgical operation. The amount of compound administered is the amount determined effective to treat congestive heart failure or to prevent a patient's fibroproliferative vasculopathy such as chronic allograft rejection or vascular restenosis following vascular trauma. The present invention also relates to a method for measuring the inhibition of adenylyl cyclase activity.
BACKGROUND ART
[0003] Adenylyl cyclases are a family of enzymes that catalyze the formation of cAMP from adenosine-5′-triphosphate (5′ATP), mediate the physiological effects of numerous hormones and neurotransmitters, and belong to a super family of membrane-bound transporters and channel proteins.
[0004] Adenosine-3′:5′-cyclic monophosphate (cAMP) is known to be the second messenger involved in signal transduction for numerous neurotransmitters and hormones, and thus has an impact upon some of the key mediators for SMC proliferation and migration. While it is known that the cAMP pathway can be regulated pharmacologically by inhibitory compounds that are of particular value in the treatment of many diseases, and there is still much interest in identifying more potent and specific agents acting on this pathway. Regulation of this pathway can be achieved through changes in the activities of cAMP-phosphodiesterases, cAMP-dependent protein kinases, or adenylyl cyclases.
[0005] Inhibitory compounds have been developed as therapeutic agents that inhibit cyclic nucleotide phosphodiesterases. Some effects of such agents are to raise cellular cAMP levels in tissues and organs on which they act. For example, theophylline, an inhibitor of all isozyme families of phosphodiesterases, is used clinically to treat asthma. Rolipram, an inhibitor of type IV phosphodiesterase, is used in the treatment of depression. And several inhibitors of type III phosphodiesterase have been used clinically to treat patients with moderate to severe heart failure. These latter drugs enhance cardiac index without elevating mean arterial blood pressure and lowering systemic vascular resistance. Therefore such compounds are believed to have significant advantages over .beta.-agonists and digitalis.
[0006] However, there is a continued need for discovering more effective and specific inhibitory compounds that act directly on adenylyl cyclases, even though inhibitory agents which indirectly activate or indirectly inhibit the enzyme may be commonly used in the treatment of such diseases. For example, drugs of the class beta-blockers are commonly used to treat hypertension and some of these act to inhibit adenylyl cyclase indirectly by blocking the stimulatory effects of the sympathetic nervous system to activate adenylyl cyclase in the heart, thereby reducing cardiac output. Agents that reduce adenylyl cyclase activity directly would be expected to have a similar cardiac-sparing effect, along with reduced cardiomyopathy and heart failure. Adenylyl cyclases can be potently and directly inhibited by analogues of adenosine, via a specific domain. This binding domain is referred to as the “P”-site from an evident requirement for an intact purine moiety. However, there is a need for more potent and direct adenylyl cyclase inhibitors.
[0007] Congestive heart failure (CHF) afflicts 3 to 4 million Americans and 400,500 to 500,000 new cases are diagnosed each year, and adenylyl cyclase plays a role in the disease progression, as discussed below. Significantly, statistics show that more than 50% of heart failure (CHF) patients die within five years of their diagnosis. It is believed to be the primary cause of 30,000 to 40,000 deaths annually.
[0008] CHF is defined as an abnormal heart function resulting in an inadequate cardiac output for metabolic needs. See E. Braunwald, Heart Disease, First Ed., W. B. Saunders, Philadelphia, page 426 (1988). The symptoms of CHF include for example, breathlessness, fatigue, weakness, leg swelling, and exercise intolerance. Initially, the conditions of patients with heart failure usually develop as the heart muscle weakens and needs to work harder to keep the blood flowing through the body. The heart failure develops, following an injury to the heart as damage caused by heart attack, long term high blood pressure or an abnormality of one of the heart valves. The weakened heart must then work harder to keep the demands of the body. Heart failure is usually not recognized until a more advanced stage of heart failure which is referred to as congestive heart failure. On physical examination, patients with CHF tend to have elevations in heart and respiratory rates, rates (an indication of fluid in the lungs), edema, jugular venous distension, and, in general, enlarged hearts. The most common cause of CHF is atherosclerosis which causes blockages in the blood vessels (coronary arteries) that provide blood flow to the heart muscle. Ultimately, such blockages may cause myocardial infarction (death of heart muscle) with subsequent decline in heart function and resultant heart failure. Other causes of CHF include valvular heart disease, hypertension, viral infections of the heart, alcohol, and diabetes. Some cases of heart failure occur without clear etiology and are called idiopathic.
[0009] CHF is also typically accompanied by alterations in one or more aspects of β-adrenergic neurohumoral function; see Feldman et al., J. Clin. Invest., 82:189-197, (1988); Bristow et al., N. Engl. J. Med., 307:205-211, (1982); Bristow et al., Circ. Res., 59:297-309 (1986); Ungerer et al., Circulation, 87: 454-461 (1993); Bristow et al., J. Clin. Invest., 92: 2737-2745 (1993); Calderone et al., Circ. Res., 69:332-343 (1991); Marzo et al., Circ.Res., 69:1546-1556 (1991); C. S. Liang et al., J.Clin. Invest., 84: 1267-1275 (1989); Roth et al., J.Clin. Invest., 91: 939-949 (1993); Hadcock and Malbon, Proc. Natl. Acad. Sci., 85:5021-5025 (1988); Hadcock et al., J. Biol. Chem., 264: 19928-19933 (1989); Mahan, et al., Proc. Natl. Acad. Sci. USA, 82:129-133 (1985); Hammond et al., Circulation, 85:269-280 (1992); Neumann et al., Lancet , 2: 936-937 (1988); Urasawa et al., G Proteins: Signal Transduction and Disease , Academic Press, London. 44-85 (1992); Bohm, Mol. Cell Biochem., 147: 147-160 (1995); Eschenhage et al., Z. Kardiol, 81 (Suppl 4): 33-40 (1992); and Yamamoto et al., J. Mol. Cell., 26: 617-626 (1994). There are other references regarding various adenylyl cyclase enzymes. see, Yoshimura et al., Proc. Natl.Acad. Sci. USA, 89:6716-6720 (1992); Ishikawa et al., J. Biol. Chem., 267:13553-13557 (1992); Fujita et al., Circulation, 90(4): Part 2) (1994);; Krupinski et al., J. Biol. Chem., 267:24858-24862 (1992); Ishikawa et al., J. Clin. Invest, 93:2224-2229 (1994); Katsushika et al., Proc. Natl. Acad. Sci. USA, 89:8774-8778 (1992); Wallach et al., FEBS Lett., 338:257-263 (1994); Watson et al., J. Biol. Chem., 269:28893-28898 (1994); Manolopoulos et al., Biochem. Biophys. Res. Commun., 208:323-331 (1995); Yu et al., FEBS Lett, 374:89-94 (1995); and Chen et al., J. Biol. Chem., 270:27525-27530 (1995).
[0010] Differential changes in the left and right ventricular adenylyl cyclase activities have been demonstrated in congestive heart failure patients (see, for example, Sethi, Rajat, et al., APStracts 3:0403H, 1196). The Sethi abstract reports that the levels of adenylyl cyclase in crude membranes from both left and right ventricles was determined upon occluding the left coronary artery in rats for 4, 8 and 16 weeks. The adenylyl cyclase activity in the presence of isoproterenol was decreased in the uninfarcted (viable) left ventricle and increased in the right ventricle subsequent to myocardial infarction. The catalytic activity of adenylyl cyclase was depressed in the viable left ventricle but was unchanged in the right ventricle. In comparison to sham controls, the basal, as well as NaF-, forskolin-, and Gpp(NH)p-stimulated adenylyl cyclase activities, were decreased in the left ventricle and increased in the right ventricle of the experimental animals. Opposite alterations in the adenylyl cyclase activities in left and right ventricles from infarcted animals were also seen when two types of purified sarcolemmal preparations were employed. These changes in adenylyl cyclase activities in the left and right ventricles were dependent upon the degree of heart failure. Furthermore, cyclic AMP contents were higher in the right ventricle and lower in the left ventricle from infarcted animals injected with saline, isoproterenol or forskolin in comparison to the controls. The results suggest differential changes in the viable left and right ventricles with respect to adenylyl cyclase activities during the development of congestive heart failure due to myocardial infarction. Accordingly, inhibiting adenylyl cyclase would be helpful in treating congestive heart failure.
[0011] Fibroproliferative vasculopathy includes restenosis following coronary bypass surgery and PTCA (percutaneous transluminal coronary angioplasty), allograft arteriosclerosis in chronic allograft rejection, diabetic angiopathy and all forms of common arteriosclerosis. Vascular intimal dysplasia and remodeling are characteristic features of reinjury following balloon angioplasty, coronary bypass surgery (Holmes et al. 1984; Holmes et al. 1988) and in chronic allograft rejection (Lemstrom and Koskinen, 1997; Hayry et al. 1993). An initial response to vascular injury is inflammatory and involves attraction of lymphocytes, macrophages and thrombocytes to the site of injury and secretion of cytokines, eicosanoids and growth factors (Ross 1993). Under the influence of growth factors and cytokines, smooth muscle cells (SMC) proliferate and migrate from the media to the intima and contribute to intimal hyperplasia and stenosis. Some key mediators of SMC proliferation and migration are IL-1, TNF alpha, PDGF, IGF1, bFGF, EGF, TGFβ and VEGF (Asahara et al. 1995; Bornfeldt et al. 1994; Ferns et al. 1991; Libby and Galis 1995, Galis et al. 1995; Gronwald et al. 1989; Hancock et al. 1994; Hayry et al. 1995; Lindner and Reidny 1991; Myllarnemi et al. 1997; Nabel et al. 1993; Shi et al. 1996; Tanaka et al. 1996) and the matrix metalloproteinases in SMC locomotion through the extracellular matrix (Bendeck et al. 1996; Galis et al. 1995).
SUMMARY OF THE INVENTION
[0012] The present invention relates to potent new adenine based inhibitors of adenylyl cyclase of formula (I):
[0013] wherein:
[0014] A is a direct link or A is divalent member selected from the group consisting of:
[0015] phenyl, thienyl, furanyl, pyrrolyl, indolyl,
[0016] wherein
[0017] each B is independently —C(—R 1 )(—R 2 )—, —O— or —N(—J—R 3 )—, and wherein only one ring B is either O or —N(—J—R 3 )—;
[0018] m and n are each independently an integer from 0-4;
[0019] q is an integer from 0 to 8;
[0020] Y is —(CH 2 ) q —, —(CH 2 ) m O—, (CH 2 ) m —N(—J 1 —)—R 4 ;
[0021] Z is —(CH 2 ) n —C(═O)—NHOH and —(CH 2 ) n COOH;
[0022] L is —(CH 2 ) q —, —(CH 2 ) m O—, —(CH 2 ) m —N—(—J 2 —)—R 5 ;
[0023] J, J 1 and J 2 are each independently —C(═O)— or a direct link;
[0024] R 1 is H, —N(—J 3 —R 6 )(—J 4 —R) or —O—J 5 —R 8 ;
[0025] wherein J 3 , J 4 and J 5 are each independently —C(═O)—, a direct link, or at least one of J 3 and J 4 is a direct link;
[0026] R 2 is H, —N(—J 6 —R 9 )(—J 7 —R 10 ) or —O—J 8 —R 11 ;
[0027] wherein J 6 , J 7 and J 8 are each independently —C(═O)—, a direct link, or at least one of J 6 and J 7 is a direct link;
[0028] R 3 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 12 ;
[0029] R 4 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 13 ;
[0030] R 5 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 14 ;
[0031] R 6 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 15 ;
[0032] R 7 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 16 ;
[0033] R 8 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 17 ;
[0034] R 9 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 18 ;
[0035] R 10 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 19 ;
[0036] R 11 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 20 ;
[0037] R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 and R 20 are each independently C 1 -C 4 alkyl, cycloalkyl or benzyl;
[0038] and all pharmaceutically acceptable isomers, salts, hydrates, solvates and prodrug derivatives thereof.
[0039] Another aspect of the invention relates to pharmaceutical compositions comprising the compound of formula I and a pharmaceutically acceptable carrier or diluent.
[0040] The adenine derivatives of the present invention inhibit adenylyl cyclases directly and are thus useful, among other uses, to inhibit or prevent a patient's fibroproliferative vasculopathy following vascular injury or a vascular surgical operation.
[0041] Another aspect of the present invention relates to a method for administering to a patient in need thereof an effective amount of an adenylyl cyclase inhibitory compound according to the invention and subsequent to the diagnosis of congestive heart failure, the occurrence of a vascular injury, or subsequent to a vascular surgical operation.
[0042] Another aspect of the invention relates to administration of the compound, either chronically after the diagnosis of congestive heart failure or for one to two weeks after the occurrence of a vascular injury or surgical operation. The amount of compound administered is an amount effective to treat or prevent a patient's congestive heart failure or fibroproliferative vasculopathy such as chronic allograft rejection or vascular restenosis following vascular trauma.
[0043] Still, another aspect of the present invention relates to adenylyl cyclase inhibitory compounds according to the invention which are useful in the preparation of covalent affinity probes and affinity chromatography matrices. Such inhibitory compounds are important to many aspects of biology, biochemistry, pharmacology, and therapeutics and will find use in the treatment of various diseases and, more specifically, treatment of cardiovascular diseases.
[0044] Other aspects, objects, features and advantages of the present invention would be apparent to one of ordinary skill in the art from the following detailed description illustrating the preferred embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0045] Definitions
[0046] In accordance with the present invention and as used herein, the following terms are defined with the following meanings, unless explicitly stated otherwise.
[0047] The term “alkenyl” refers to a trivalent straight chain or branched chain unsaturated aliphatic radical. The term “alkinyl” (or “alkynyl”) refers to a straight or branched chain aliphatic radical that includes at least two carbons joined by a triple bond. If no number of carbons is specified alkenyl and alkinyl each refer to radicals having from 2-12 carbon atoms.
[0048] The term “alkyl” refers to saturated aliphatic groups including straight-chain, branched-chain and cyclic groups having the number of carbon atoms specified, or if no number is specified, having up to 12 carbon atoms. The term “cycloalkyl” as used herein refers to a mono-, bi-, or tricyclic aliphatic ring having 3 to 14 carbon atoms and preferably 3 to 7 carbon atoms.
[0049] As used herein, the terms “carbocyclic ring structure” and “C 3-16 carbocyclic mono, bicyclic or tricyclic ring structure” or the like are each intended to mean stable ring structures having only carbon atoms as ring atoms wherein the ring structure is a substituted or unsubstituted member selected from the group consisting of: a stable monocyclic ring which is aromatic ring (“aryl”) having six ring atoms; a stable monocyclic non-aromatic ring having from 3 to 7 ring atoms in the ring; a stable bicyclic ring structure having a total of from 7 to 12 ring atoms in the two rings wherein the bicyclic ring structure is selected from the group consisting of ring structures in which both of the rings are aromatic, ring structures in which one of the rings is aromatic and ring structures in which both of the rings are non-aromatic; and a stable tricyclic ring structure having a total of from 10 to 16 atoms in the three rings wherein the tricyclic ring structure is selected from the group consisting of: ring structures in which three of the rings are aromatic, ring structures in which two of the rings are aromatic and ring structures in which three of the rings are non-aromatic. In each case, the non-aromatic rings when present in the monocyclic, bicyclic or tricyclic ring structure may independently be saturated, partially saturated or fully saturated. Examples of such carbocyclic ring structures include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, cyclooctyl, [3.3.0]bicyclooctane, [4.3.0]bicyclononane, [4.4.0]bicyclodecane (decalin), 2.2.2]bicyclooctane, fluorenyl, phenyl, naphthyl, indanyl, adamantyl, or tetrahydronaphthyl (tetralin). Moreover, the ring structures described herein may be attached to one or more indicated pendant groups via any carbon atom which results in a stable structure. The term “substituted” as used in conjunction with carbocyclic ring structures means that hydrogen atoms attached to the ring carbon atoms of ring structures described herein may be substituted by one or more of the substituents indicated for that structure if such substitution(s) would result in a stable compound.
[0050] The term “aryl” which is included with the term “carbocyclic ring structure” refers to an unsubstituted or substituted aromatic ring, substituted with one, two or three substituents selected from lower alkoxy, lower alkyl, lower alkylamino, hydroxy, halogen, cyano, hydroxyl, mercapto, nitro, thioalkoxy, carboxaldehyde, carboxyl, carboalkoxy and carboxamide, including but not limited to carbocyclic aryl, heterocyclic aryl, and biaryl groups and the like, all of which may be optionally substituted. Preferred aryl groups include phenyl, halophenyl, loweralkylphenyl, napthyl, biphenyl, phenanthrenyl and naphthacenyl.
[0051] The term “arylalkyl” which is included with the term “carbocyclic aryl” refers to one, two, or three aryl groups having the number of carbon atoms designated, appended to an alkyl group having the number of carbon atoms designated. Suitable arylalkyl groups include, but are not limited to, benzyl, picolyl, naphthylmethyl, phenethyl, benzyhydryl, trityl, and the like, all of which may be optionally substituted.
[0052] As used herein, the term “heterocyclic ring” or “heterocyclic ring system” is intended to mean a substituted or unsubstituted member selected from the group consisting of stable monocyclic ring having from 5-7 members in the ring itself and having from 1 to 4 hetero ring atoms selected from the group consisting of N, O and S; a stable bicyclic ring structure having a total of from 7 to 12 atoms in the two rings wherein at least one of the two rings has from 1 to 4 hetero atoms selected from N, O and S, including bicyclic ring structures wherein any of the described stable monocyclic heterocyclic rings is fused to a hexane or benzene ring; and a stable tricyclic heterocyclic ring structure having a total of from 10 to 16 atoms in the three rings wherein at least one of the three rings has from 1 to 4 hetero atoms selected from the group consisting of N, O and S. Any nitrogen and sulfur atoms present in a heterocyclic ring of such a heterocyclic ring structure may be oxidized. Unless indicated otherwise the terms “heterocyclic ring” or “heterocyclic ring system” include aromatic rings, as well as non-aromatic rings which can be saturated, partially saturated or fully saturated non-aromatic rings. Also, unless indicated otherwise the term “heterocyclic ring system” includes ring structures wherein all of the rings contain at least one hetero atom as well as structures having less than all of the rings in the ring structure containing at least one hetero atom, for example bicyclic ring structures wherein one ring is a benzene ring and one of the rings has one or more hetero atoms are included within the term “heterocyclic ring systems” as well as bicyclic ring structures wherein each of the two rings has at least one hetero atom. Moreover, the ring structures described herein may be attached to one or more indicated pendant groups via any hetero atom or carbon atom which results in a stable structure. Further, the term “substituted” means that one or more of the hydrogen atoms on the ring carbon atom(s) or nitrogen atom(s) of the each of the rings in the ring structures described herein may be replaced by one or more of the indicated substituents if such replacement(s) would result in a stable compound. Nitrogen atoms in a ring structure may be quatemized, but such compounds are specifically indicated or are included within the term “a pharmaceutically acceptable salt” for a particular compound. When the total number of O and S atoms in a single heterocyclic ring is greater than 1, it is preferred that such atoms not be adjacent to one another. Preferably, there are no more than one O or S ring atoms in the same ring of a given heterocyclic ring structure.
[0053] Examples of monocyclic and bicyclic heterocyclic ring systems, in alphabetical order, are acridinyl, azocinyl, benzimidazolyl, benzofuranyl, benzothiofuranyl, benzothiophenyl, benzoxazolyl, benzthiazolyl, benztriazolyl, benztetrazolyl, benzisoxazolyl, benzisothiazolyl, benzimidazalinyl, carbazolyl, 4aH-carbazolyl, carbolinyl, chromanyl, chromenyl, cinnolinyl, decahydroquinolinyl, 2H,6H-1,5,2-dithiazinyl, dihydrofuro[2,3-b]tetrahydrofuran, furanyl, furazanyl, imidazolidinyl, imidazolinyl, imidazolyl, 1H-indazolyl, indolinyl, indolizinyl, indolyl, 3H-indolyl, isobenzofuranyl, isochromanyl, isoindazolyl, isoindolinyl, isoindolyl, isoquinolinyl (benzimidazolyl), isothiazolyl, isoxazolyl, morpholinyl, naphthyridinyl, octahydroisoquinolinyl, oxadiazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, oxazolidinyl, oxazolyl, oxazolidinyl, pyrimidinyl, phenanthridinyl, phenanthrolinyl, phenazinyl, phenothiazinyl, phenoxathiinyl, phenoxazinyl, phthalazinyl, piperazinyl, piperidinyl, pteridinyl, purinyl, pyranyl, pyrazinyl, pyroazolidinyl, pyrazolinyl, pyrazolyl, pyridazinyl, pryidooxazole, pyridoimidazole, pyridothiazole, pyridinyl, pyridyl, pyrimidinyl, pyrrolidinyl, pyrrolinyl, 2H-pyrrolyl, pyrrolyl, quinazolinyl, quinolinyl, 4H-quinolizinyl, quinoxalinyl, quinuclidinyl, tetrahydrofuranyl, tetrahydroisoquinolinyl, tetrahydroquinolinyl, 6H-1,2,5-thiadazinyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, thianthrenyl, thiazolyl, thienyl, thienothiazolyl, thienooxazolyl, thienoimidazolyl, thiophenyl, triazinyl, 1,2,3-triazolyl, 1,2,4-triazolyl, 1,2,5-triazolyl, 1,3,4-triazolyl and xanthenyl. Preferred heterocyclic ring structures include, but are not limited to, pyridinyl, furanyl, thienyl, pyrrolyl, pyrazolyl, pyrrolidinyl, imidazolyl, indolyl, benzimidazolyl, 1H-indazolyl, oxazolinyl, or isatinoyl. Also included are fused ring and spiro compounds containing, for example, the above heterocyclic ring structures.
[0054] As used herein the term “aromatic heterocyclic ring system” has essentially the same definition as for the monocyclic and bicyclic ring systems except that at least one ring of the ring system is an aromatic heterocyclic ring or the bicyclic ring has an aromatic or non-aromatic heterocyclic ring fused to an aromatic carbocyclic ring structure.
[0055] The terms “halo” or “halogen” as used herein refer to Cl, Br, F or I substituents. The term “haloalkyl”, and the like, refer to an aliphatic carbon radicals having at least one hydrogen atom replaced by a Cl, Br, F or I atom, including mixtures of different halo atoms. Trihaloalkyl includes trifluoromethyl and the like as preferred radicals, for example.
[0056] The term “alkylene chain” refers to straight or branched chain unsaturated divalent radical consisting solely of carbon and hydrogen atoms containing no unsaturation and having from one to six carbon atoms, e.g., methylene, ethylene, propylene, butylenes, and the like. The term “methylene” refers to —CH 2 —. The term “Bu” refers to “butyl” or —CH 2 CH 2 CH 2 CH 2 —; the term “Ph” refers to “phenyl”; the term “Me” refers to “methyl” or —CH 3 ; the term “Et” refers to “ethyl” or —CH 2 CH 3 ; the term “Bu(t)” or “t-Bu” refers to “tert-butyl” or —C(CH 3 ) 4 .
[0057] The term “pharmaceutically acceptable salts” includes salts of compounds derived from the combination of a compound and an organic or inorganic acid. These compounds are useful in both free base and salt form. In practice, the use of the salt form amounts to use of the base form; both acid and base addition salts are within the scope of the present invention.
[0058] “Pharmaceutically acceptable acid addition salt” refers to salts retaining the biological effectiveness and properties of the free bases and which are not biologically or otherwise undesirable, formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like, and organic acids such as acetic acid, propionic acid, glycolic acid, pyruvic acid, oxalic acid, maleic acid, malonic acid, succinic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, salicyclic acid and the like.
[0059] “Pharmaceutically acceptable base addition salts” include those derived from inorganic bases such as sodium, potassium, lithium, ammonium, calcium, magnesium, iron, zinc, copper, manganese, aluminum salts and the like. Particularly preferred are the ammonium, potassium, sodium, calcium and magnesium salts. Salts derived from pharmaceutically acceptable organic nontoxic bases include salts of primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines and basic ion exchange resins, such as isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, ethanolamine, 2-diethylaminoethanol, trimethamine, dicyclohexylamine, lysine, arginine, histidine, caffeine, procaine, hydrabamine, choline, betaine, ethylenediamine, glucosamine, methylglucamine, theobromine, purines, piperizine, piperidine, N-ethylpiperidine, polyamine resins and the like. Particularly preferred organic nontoxic bases are isopropylamine, diethylamine, ethanolamine, trimethamine, dicyclohexylamine, choline, and caffeine.
[0060] “Biological property” for the purposes herein means an in vivo effector or antigenic function or activity that is directly or indirectly performed by a compound of this invention that are often shown by in vitro assays. Effector functions include receptor or ligand binding, any enzyme activity or enzyme modulatory activity, any carrier binding activity, any hormonal activity, any activity in promoting or inhibiting adhesion of cells to an extracellular matrix or cell surface molecules, or any structural role. Antigenic functions include possession of an epitope or antigenic site that is capable of reacting with antibodies raised against it.
[0061] Preferred Embodiments
[0062] In one preferred embodiment the present invention relates to a compound of the formula (I):
[0063] wherein:
[0064] A is a direct link or A is divalent member selected from the group consisting of:
[0065] phenyl, thienyl, furanyl, pyrrolyl, indolyl,
[0066] wherein
[0067] each B is independently —C(—R 1 )(—R 2 )—, —O— or —N(—J—R 3 )—, and wherein only one ring B is either O or —N(—J—R 3 )—;
[0068] m and n are each independently an integer from 0-4;
[0069] q is an integer from 0 to 8;
[0070] Y is —(CH 2 ) q —, —(CH 2 ) m O—, —(CH 2 ) m —N(—J 1 —)—R 4 ;
[0071] Z is —(CH 2 ) n —C(═O)—NHOH and —(CH 2 ) n COOH;
[0072] L is —(CH 2 ) q —, —(CH 2 ) m O—, —(CH 2 ) m —N—(—J 2 —)—R 5 ;
[0073] J, J 1 and J 2 are each independently —C(═O)— or a direct link;
[0074] R 1 is H, —N(—J 3 —R)(—J 4 —R 7 ) or —O—J—R 8 , wherein J 3 , J 4 and J 5 are each independently —C(═O)— or a direct link, and at least one of J 3 and J 4 is a direct link;
[0075] R 2 is H, —N(—J 6 —R 9 )(—J 7 —R 10 ) or —O—J 8 —R 11 , wherein J 6 , J 7 and J 8 are each independently a —C(═O)— or a direct link, and at least one of J 6 and J 7 is a direct link;
[0076] R 3 is H, C 1 -C 8 alkyl, CF 3 , or —O—R
[0077] R 4 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 13 ;
[0078] R 5 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 14 ;
[0079] R 6 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 15 ;
[0080] R 7 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 16 ;
[0081] R 8 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 17 ;
[0082] R 9 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 18 ;
[0083] R 10 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 19 ;
[0084] R 11 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 20 ;
[0085] R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 and R 20 are each independently a C 1 -C 4 alkyl, cycloalkyl or benzyl;
[0086] and all pharmaceutically acceptable isomers, salts, hydrates, solvates and prodrug derivatives thereof.
[0087] The pharmaceutically acceptable salts of the compounds according to formula (I) include pharmaceutically acceptable acid addition salts, metal salts, ammonium salts, organic amine addition salts, amino acid addition salts, etc. Examples of the pharmaceutically acceptable acid addition salts of the compounds of formula (I) are inorganic acid addition salts such as hydrochloride, sulfate and phosphate, and organic acid addition salts such as acetate, maleate, fumarate, tartrate, citrate and methanesulfonate. Examples of the pharmaceutically acceptable metal salts are alkali metal salts such as sodium salt and potassium salt, alkaline earth metal salts such as magnesium salt and calcium salt, aluminum salt and zinc salt. Examples of the pharmaceutically acceptable ammonium salts are ammonium salt and tetramethyl ammonium salt. Examples of the pharmaceutically acceptable organic amine addition salts include heterocyclic amine salts such as morpholine and piperidine salts. Examples of the pharmaceutically acceptable amino acid addition salts are salts with lysine, glycine and phenylalanine.
[0088] This invention also encompasses prodrug derivatives of the compounds contained herein. The term “prodrug” refers to a pharmacologically inactive derivative of a parent drug molecule that requires biotransformation, either spontaneous or enzymatic, within the organism to release the active drug. Prodrugs are variations or derivatives of the compounds of this invention which have groups cleavable under metabolic conditions. Prodrugs become the compounds of the invention which are pharmaceutically active in vivo, when they undergo solvolysis under physiological conditions or undergo enzymatic degradation. Prodrug compounds of this invention may be called single, double, triple etc., depending on the number of biotransformation steps required to release the active drug within the organism, and indicating the number of functionalities present in a precursor-type form. Prodrug forms often offer advantages of solubility, tissue compatibility, or delayed release in the mammalian organism (see, Bundgard, Design of Prodrugs, pp. 7-9, 21-24, Elsevier, Amsterdam 1985 and Silverman, The Organic Chemistry of Drug Design and Drug Action, pp. 352-401, Academic Press, San Diego, Calif., 1992). Prodrugs commonly known in the art include acid derivatives well known to practitioners of the art, such as, for example, esters prepared by reaction of the parent acids with a suitable alcohol, or amides prepared by reaction of the parent acid compound with an amine, or basic groups reacted to form an acylated base derivative. Moreover, the prodrug derivatives of this invention may be combined with other features herein taught to enhance bioavailability. The preparation of pharmaceutically acceptable isomers, solvates or hydrates would be apparent to one of ordinary skill in the art.
[0089] In the compounds of this invention, carbon atoms bonded to four non-identical substituents are asymmetric. Accordingly, the compounds may exist as diastereoisomers, enantiomers or mixtures thereof. The syntheses described herein may employ racemates, enantiomers or diastereomers as starting materials or intermediates. Diastereomeric products resulting from such syntheses may be separated by chromatographic or crystallization methods, or by other methods known in the art. Likewise, enantiomeric product mixtures may be separated using the same techniques or by other methods known in the art. Each of the asymmetric carbon atoms, when present in the compounds of this invention, may be in one of two configurations (R or S) and both are within the scope of the present invention.
[0090] In a preferred embodiment, the invention provides compounds according to formula (I):
[0091] wherein:
[0092] A is a direct link, or
[0093] A is divalent member selected from the group consisting of:
[0094] wherein
[0095] each B is independently —C(—R 1 )(—R 2 )—, —O— or —N(—J—R 3 )—, and wherein only one ring B is either O or —N(—J—R 3 )—;
[0096] m and n are each independently an integer from 0-4;
[0097] q is an integer from 0 to 8;
[0098] Y is a —(CH 2 ) q — and —(CH 2 ) m O—;
[0099] Z is —(CH 2 ) n —C(═O)—NHOH and —(CH 2 ) n COOH;
[0100] L is —(CH 2 ) q — and —(CH 2 ) m O—;
[0101] J is —C(═O)— or a direct link;
[0102] R 1 is H or —O—J 5 —R 8 , wherein J 5 is a —C(═O)— or a direct link;
[0103] R 2 is a H or —O—J 8 —R 11 , wherein J 8 is —C(═O)— or a direct link;
[0104] R 8 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 17 ;
[0105] R 11 is H, C 1 -C 8 alkyl, CF 3 , or —O—R 20 ;
[0106] R 17 and R 20 are each independently a C 1 -C 4 alkyl, cycloalkyl or benzyl;
[0107] and all pharmaceutically acceptable isomers, salts, hydrates, solvates and prodrug derivatives thereof.
[0108] A further preferred embodiment is a compound of the formula (I):
[0109] wherein:
[0110] A is divalent member selected from the group consisting of:
[0111] wherein
[0112] each B is independently the substituted group —C(—R 1 )(—R 2 )—;
[0113] Y is —(CH 2 ) q — and —(CH 2 ) m O—;
[0114] Z is —(CH 2 ) n —C(═O)—NHOH;
[0115] L is a —(CH 2 ) q —;
[0116] m and n are each independently an integer from 0-4;
[0117] q is an integer from 0 to 8; and
[0118] R 1 and R 2 are each H;
[0119] and all pharmaceutically acceptable isomers, salts, hydrates, solvates and prodrug derivatives thereof.
[0120] The compounds may be prepared using methods and procedures in the Examples presented herein. Starting materials may be made or obtained as described therein as well. Leaving groups such as halogen, lower alkoxy, lower alkylthio, lower alkylsulfonyloxy, arylsulfonyloxy, etc, may be utilized when necessary except for the reaction point, followed by deprotection. Suitable amino protective groups are, for example, those described in T. W. Greene, Protective Groups in Organic Synthesis , John Wiley & Sons Inc. (1981), etc., such as ethoxycarbonyl, t-butoxycarbonyl, acetyl and benzyl. The protective groups can be introduced and eliminated according to conventional methods used in organic synthetic chemistry [e.g., T. W. Greene, Protective Groups in Organic Synthesis , John Wiley & Sons Inc. (1981)].
[0121] In such processes, if the defined groups change under the conditions of the working method or are not appropriate for carrying out the method, the desired compound can be obtained by using the methods for introducing and eliminating protective groups which are conventionally used in organic synthetic chemistry. See, e.g., T. W. Greene, Protective Groups in Organic Synthesis , John Wiley & Sons Inc. (1981)], supra. Conversion of functional groups contained in the substituents can be carried out by known methods. See e.g., R. C. Larock, Comprehensive Organic Transformations (1989), in addition to the above-described processes, and some of the active compounds of formula I may be utilized as intermediates for further synthesizing novel derivatives according to formula I.
[0122] The intermediates and the desired compounds in the processes described above can be isolated and purified by purification methods conventionally used in organic synthetic chemistry, for example, neutralization, filtration, extraction, washing, drying, concentration, recrystallization, and various kinds of chromatography. The intermediates may be subjected to the subsequent reaction without purification.
[0123] There may be tautomers for some formula I, and the present invention covers all possible isomers including tautomers and mixtures thereof. Where chiral carbons lend themselves to two different enantiomers, both enantiomers are contemplated as well as procedures for separating the two enantiomers. There may be tautomers for some formula I, and the present invention covers all possible isomers including tautomers and mixtures thereof, the process of making would be apparent to one of ordinary skill in the art. Where chiral carbons lend themselves to two different enantiomers, both enantiomers are contemplated as well as procedures for separating the two enantiomers. In the compounds of this invention, carbon atoms bonded to four non-identical substituents are asymmetric. Accordingly, the compounds may also exist as diastereoisomers, enantiomers or mixtures thereof. The syntheses described herein may employ racemates, enantiomers or diastereomers as starting materials or intermediates. Diastereomeric products resulting from such syntheses may be separated by chromatographic or crystallization methods, or by other methods known in the art. Likewise, enantiomeric product mixtures may be separated using the same techniques or by other methods known in the art. Each of the asymmetric carbon atoms, when present in the compounds of this invention, may be in one of two configurations (R or S) and both are within the scope of the present invention. In the processes described above, the final products may, in some cases, contain a small amount of diastereomeric or enantiomeric products, however these products do not affect their therapeutic or diagnostic application.
[0124] In the case where a salt of a compound of formula I is desired and the compound is produced in the form of the desired salt, it can be subjected to purification as such. In the case where a compound of formula I is produced in the free state and its salt is desired, the compound of formula I is dissolved or suspended in a suitable organic solvent, followed by addition of an acid or a base to form a salt.
[0125] The following non-limiting reaction Schemes I-XI illustrate preferred embodiments of the invention with respect to making compounds according to the invention.
[0126] The following general procedures and particular non-limiting examples refer to preparation of compounds in Schemes I-X and are provided to better illustrate the present invention.
[0127] All of the cited patents and publications are incorporated herein by reference. The following specific examples are provided to better assist the reader in the various aspects of practicing the present invention. As these specific examples are merely illustrative, nothing in the following descriptions should be construed as limiting the invention in any way.
EXAMPLES
[0128] General Procedure A—Adenine Alkylations
[0129] Adenine (1.18 mmole) was combined with an alkyl bromide (3.54 mmoles), K 2 CO 3 (5.91 mmoles) and DMF (5.00 mL). The mixture was heated to 60° C. for 20 hours. After cooling to room temperature, the reaction was diluted with brine (50 mL) and washed with EtOAc (3×20 mL). The combined organic washes were dried over anhydrous MgSO 4 , filtered and concentrated to dryness. The product was purified on silica gel (5% MeOH/CHCl 3 ).
[0130] General Procedure B—Hydroxamic Acids
[0131] KOH (3.8 M in MeOH, 0.45 mL) was added to HONH 2 HCl (1.6 M in MeOH, 0.67 mL) and cooled to 0° C. for 2 hours. A methyl or ethyl ester (0.15 mmoles) was dissolved in MeOH (0.31 mL) and the HONH 2 solution was added by filtration. After stirring for 45 minutes at room temperature, the reaction was concentrated to dryness and the residue was purified by reverse phase preparative HPLC (0-10% CH 3 CN/30 minutes). The isolated product was desalted with MP-carbonate resin (Argonaut) in MeOH, filtered and concentrated to dryness giving the desired hydroxamic acid.
[0132] General Procedure C—Carboxylic Acids
[0133] A methyl or ethyl ester (0.53 mmoles) was dissolved in MeOH (2.40 mL) and NaOH (2.00 M in H 2 O, 1.60 mmoles) was added. The reaction was stirred at room temperature for 2.5 hours after which, it was acidified to pH=2 with DOWEX acid resin (50WX 2 -100, MeOH washed). The reaction was filtered and concentrated to dryness giving the desired carboxylic acid.
[0134] General Procedure D—Rhodium Acetate
[0135] An alcohol (6.08 mmoles) was dissolved in CH 2 Cl 2 (65 mL) and [Rh(OAc)2]2 (0.15 mmole) was added. Ethyl diazoacetate (13.30 mmoles) was added dropwise and the reaction was stirred at room temperature for 24 hours. After concentrating to dryness, the product was purified on silica gel (20% EtOAc/hexane).
[0136] General Procedure E—Acetate/p-nitrobenzoate Cleavage (NaOMe)
[0137] An acetate or p-nitrobenzoate (5.18 mmoles) was dissolved in anhydrous MeOH (15 mL) and catalytic NaOMe (solution in MeOH) was added. The reaction was stirred at room temperature for 24 hours after which, it was quenched with H2O (1.0 mL) and concentrated to dryness. The product was purified on silica gel (50% EtOAc/Hexane).
[0138] General Procedure F—Adenine Mitsunobu
[0139] An allylic alcohol (10.93 mmoles), triphenylphosphine (10.93 mmoles) and adenine (10.93 mmoles) were dissolved in THF (40 mL) and cooled to 0° C. Diethyl azodicarboxylate (10.93 mmoles) was added dropwise and the reaction was stirred at room temperature for 18 hours. After heating the reaction to 40° C. for an additional 4 hours, the mixture was cooled to room temperature and the solids were removed by filtration. The filtrate was concentrated to dryness and the residue was purified on silica gel (EtOAc then 5% MeOH/CHCl 3 ).
[0140] General Procedure G—Olefin Hydrogenation (also Azide Reduction)
[0141] An olefin (100 mg) and 10% Pd/C (25 mg) were placed under Argon and MeOH (10 mL) was added. The mixture was degassed under vacuum and stirred under H 2 (1 atm) for 20 hours. The reaction was filtered and concentrated giving the desired product.
[0142] General Procedure H—TBDMS Protection
[0143] An alcohol (72.24 mmoles) was dissolved in THF (200 mL) and imidazole (108.36 mmoles) was added followed by TBDMS-Cl (90.30 mmoles). The reaction was stirred at room temperature for 24 hours after which, the solids were removed by filtration and the filtrate was concentrated to dryness. The residue was dissolved in EtOAc (300 HL) and washed with HCl (1N, 3×50 mL), saturated NaHCO 3 (3×50 mL) and brine (50 mL). The organic phase was dried over anhydrous MgSO 4 , filtered and concentrated and the residue was used with no further purification.
[0144] General Procedure I—TBDMS Cleavage (AcOHfTHF/Water)
[0145] A TBDMS ether (4.52 mmoles) was combined with THF (1 mL), H 2 O (1 mL) and acetic acid (3 mL). The reaction was stirred at room temperature for 6 hours after which, it was azeotroped with benzene (3×15 mL). The residue was dried under vacuum and purified on silica gel (25% EtOAc/Hexane).
[0146] General Procedure J—p-nitrobenzoic Acid Mitsunobu
[0147] An allylic alcohol (60.70 mmoles), p-nitrobenzoic acid (242.81 mmoles) and triphenylphospine (242.81 mmoles) were combined with THF (200 mL) and cooled to 0° C. under argon. Diethylazodicarboxylate (242.81 mmoles) was added dropwise and the reaction was stirred at room temperature for 15 hours and 40° C. for an additional 3 hours. After cooling to room temperature, the reaction was concentrated to dryness and the residue was diluted with EtOAc (200 mL). The resulting solution was washed with HCl (1N, 3×50 mL), brine (50 mL), saturated NaHOC 3 (3×50 mL) and brine (50 mL). After drying over anhydrous MgSO 4 , the organics were filtered, concentrated and stirred with Et 2 O (150 mL) for 18 hours. The resulting solids were removed by filtration and the filtrate was concentrated to dryness. The isolated residue was used without further purification.
[0148] General Procedure K—TBDMS Cleavage (TBAF)
[0149] A TBDMS ether (69.58 mmoles) was dissolved in THF (500 mL) and tetrabutylammonium fluoride (1M in THF, 104 mL) was added. The reaction was stirred at room temperature for 2 hours and concentrated to dryness. The residue was filtered through silica gel (EtOAc) and again concentrated to dryness. Final purification was achieved on silica gel (10% then 25% then 50% EtOAc/Hexane).
[0150] General Procedure L—Allyl Chloride
[0151] An allylic alcohol (46.17 mmoles) was dissolved in CH 2 Cl 2 and diisopropylethyl-amine (69.25 mmoles) was added. The resulting solution was cooled to 0° C. under argon and methanesulfonyl chloride (57.71 mmoles) was added. After stirring at 0° C. for 3 hours, the reaction was diluted with EtOAc (600 mL). The mixture was then washed with HCl (1N, 3×50 mL), saturated NaHCO 3 (3×50 mL) and brine (50 mL). The organics were dried over anhydrous MgSO 4 , filtered and concentrated and the residue was purified on silica gel (5% EtOAc/Hexane).
[0152] General Procedure M—Malonate Coupling
[0153] NaH (60%, 149.03 mmoles) was suspended in anhydrous THF (400 mL) and cooled to 0° C. under argon. Dimethylmalonate (149.03 mmoles) was added dropwise over 30 minutes and the reaction was allowed to warm to room temperature. An allyl chloride (29.81 mmoles) was dissolved in anhydrous THF (100 mL) and added to the malonate solution via cannula. After heating to 75° C. for 19 hours, the reaction was cooled, concentrated to a volume of 150 mL and diluted with 50% EtOAc/Hexane (300 mL). The resulting solution was washed with saturated NH 4 Cl (3×50 mL) and brine (2×50 mL). Following concentration, the organics were partitioned between hexane (150 mL) and H 2 O (150 mL). The hexane layer was further washed with H 2 O (2×50 mL), dried over anhydrous MgSO 4 , filtered and concentrated. The residue was purified on silica gel (5% EtOAc/Hexane).
[0154] General Procedure N—Decarboxylation (LiI)
[0155] A substituted malonate (31.93 mmoles) was combined with LiI (191.58 mmoles) and dissolved in DMF (260 mL). The mixture was degassed under vacuum, placed under argon and heated to 130° C. for 17 hours. After cooling to room temperature, the reaction was diluted with 25% EtOAc/Hexane (1500 mL) and washed with H 2 O (3×300 mL) and brine (100 mL). The organic phase was dried over anhydrous MgSO 4 , filtered and concentrated. The resulting residue was purified on silica gel (5% EtOAc/Hexane).
[0156] General Procedure O—Tritylation
[0157] An allylic alcohol (9.39 mmoles), trityl chloride (46.96 mmoles) and DMAP (56.36 mmoles) were combined and dissolved in DMF (30 mL). After heating to 100° C. for 20 hours, the reaction was cooled to room temperature and diluted with H20 (200 mL). The aqueous mixture was washed with 50% EtOAc/Hexane (200 mL) and the organics were sequentially washed with HCl (1N, 3×25 mL), saturated NaHCO 3 (3×25 mL) and brine (25 mL). The organics were dried over MgSO 4 , filtered, concentrated to dryness and used without further purification.
[0158] General Procedure P—Trityl Cleavage (TsOH)
[0159] A trityl ether (15.75 mmoles) was dissolved in MeOH (100 mL) and p-toluene-sulfonic acid (0.79 mmoles) was added. After stirring at room temperature for 1.25 hours, the reaction was quenched with saturated NaHCO 3 (100 mL). The resulting mixture was washed with EtOAc (3×100 mL) and the combined organic extracts were washed with brine (50 mL). After drying over anhydrous MgSO 4 , the product was purified on silica gel (25% then 50% EtOAc/Hexane).
[0160] General Procedure O—Methyl Ester Formation (MeOH, Ac-Cl)
[0161] Acetyl chloride (9.00 mmoles) was slowly added to MeOH (35.00 mL) and cooled to 0° C. A carboxylic acid (7.87 mmoles) was added and the resulting mixture was stirred at room temperature for 4 hours. Concentration of the reaction mixture provided the desired product requiring no further purification.
[0162] General Procedure R—Coupling with Pyrimidine
[0163] An amine hydrochloride (7.97 mmoles) was combined with dichloronitro-pyrimidine (11.95 mmoles) and EtOH (80 mL). Triethylamine (23.90 mmoles) was added and the reaction was stirred at room temperature for 3.5 hours. Following dilution with EtOAc (320 mL), the mixture was sequentially washed with HCl (1N, 3×50 mL), saturated NaHCO 3 (3×30 mL) and brine (30 mL). The organics were dried over anhydrous MgSO 4 , filtered and concentrated. The isolated residue was used with no further purification.
[0164] General Procedure S—Nitro Group Reduction (SnCl 2 )
[0165] A nitropyrimidine (9.36 mmoles) was dissolved in EtOH (75 mL) and SnCl 2 (28.09 mmoles) was added. The reaction was heated to reflux for 50 minutes and cooled to room temperature. Following quenching with saturated NaHCO 3 (300 mL), the reaction was washed with EtOAc (3×75 mL). The organic extracts were washed with brine (2×75 mL), dried over anhydrous MgSO 4 , filtered and concentrated. No further purification was required.
[0166] General Procedure T—Purine Formation (orthoformate, Ms-OH)
[0167] A diaminopyrimidine (9.36 mmoles) was dissolved in trimethylorthoformate (25 mL) and methanesulfonic acid (0.22 mL) was added. The reaction was stirred at room temperature for 4.5 hours and diluted with EtOAc (150 mL). The resulting mixture was washed with saturated NaHCO 3 (3×25 mL) and brine (25 mL). The organic phase was dried over anhydrous MgSO 4 , filtered and concentrated. The product was purified on silica gel (50% EtOAc/Hexane).
[0168] General Procedure U—Azidopurine
[0169] A chloropurine (3.02 mmoles), sodium azide (9.06 mmoles), EtOH (13 mL) and H 2 O (6.5 mL) were combined and heated to 50° C. for 20 hours. After stirring for an additional 17 hours at room temperature, the reaction was concentrated to dryness. The residue was diluted with H 2 O (20 mL) and the resulting solids were filtered, washed with H 2 O and dried in a dessicator. No further purification was required.
[0170] General Procedure V—Azide reduction (SnCl 2 )
[0171] An azidopurine (0.42 mmoles) was dissolved in EtOH (3.25 mL) and SnCl 2 (1.27 mmoles) was added. The reaction was heated to reflux for 20 minutes and cooled to room temperature. Following quenching with saturated NaHCO 3 (15 mL), the reaction was washed with EtOAc (3×15 mL). The organic extracts were dried over anhydrous MgSO4, filtered and concentrated. No further purification was required.
[0172] HPLC Methods
[0173] A 10%-90% CH 3 CN/10 minutes
[0174] B 0%-90% CH 3 CN/10 minutes
[0175] C 5%-85% CH 3 CN/9 minutes
[0176] Methyl-3-(9-adenenyl)-propionoate (3a)
[0177] Compound 3a was prepared by coupling adenine with methylbromopropionate according to general procedure A. Yield=7%. TLC: R f =0.17 (5% MeOH/CHCl 3 ). 1 H NMR (400 MHz, DMSO): δ3.10 (t, 2H), 3.70 (s, 3H), 4.50 (t, 2H), 7.30 (s, 2H), 8.20 (s, 1H), 8.23 (s, 1H).
[0178] Ethyl-4-(9-adenenyl)-butyrate (3b)
[0179] Compound 3b was prepared by coupling adenine with ethylbromobutyrate according to general procedure A. Yield=60%. TLC: R f =0.15 (5% MeOH/CHCl 3 ). 1 H NMR (400 MHz, DMSO): δ1.25 (t, 3H), 2.15 (m, 2H), 2.40 (t, 2H), 4.10 (q, 2H), 4.30 (t, 2H), 7.30 (s, 2H), 8.23 (s, 1H), 8.25 (s, 1H).
[0180] Methyl-5-(9-adenenyl)-pentanoate (3c)
[0181] Compound 3c was prepared by coupling adenine with methylbromopentanoate according to general procedure A. Yield=40%. TLC: R f =0.26 (5% MeOH/CHCl 3 ). Purity: >95% (HPLC method A). 1 H NMR (400 MHz, DMSO): δ1.58 (m, 2H), 1.95 (m, 2H), 2.45 (t, 2H), 3.65 (s, 3H), 4.25 (t, 2H), 7.30 (s, 2H), 8.23 (s, 1H), 8.25 (s, 1H).
[0182] Ethyl-6-(9-adenenyl)-hexanoate (3d)
[0183] Compound 3d was prepared by coupling adenine with ethylbromohexanoate according to general procedure A. Yield=55%. TLC: R f =0.22 (5% MeOH/CHCl 3 ). Purity: >90% (HPLC method A). 1 H NMR (400 MHz, DMSO): δ1.25 (t, 3H), 1.35 (m, 2H), 1.65 (m, 2H), 1.90 (m, 2H), 2.35 (t, 2H), 4.10 (q, 2H), 4.25 (t, 2H), 8.23 (s, 1H), 8.25 (s, 1H).
[0184] Ethyl-7-(9-adenenyl)-heptanoate (3e)
[0185] Compound 3e was prepared by coupling adenine with ethylbromoheptanoate according to general procedure A. Yield=39%. TLC: R f =0.25 (5% MeOH/CHCl 3 ). Purity: >95% (HPLC method A). 1 H NMR (400 MHz, DMSO): δ1.25 (t, 3H), 1.35 (m, 4H), 1.60 (m, 2H), 1.90 (m, 2H), 2.35 (t, 2H), 4.15 (q, 2H), 4.25 (t, 2H), 7.30 (s, 2H), 8.24 (s, 1H), 8.25 (s, 1H).
[0186] N-Hydroxy-3-(9-adenenyl)-propionamide (4a)
[0187] Compound 4a was prepared by subjecting compound 3a to general procedure B. Yield=60%. TLC: R f =0.17 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.70 (t, 2H), 4.45 (t, 2H), 7.30 (s, 2H), 8.10 (s, 1H), 8.25 (s, 1H), 8.90 (s, 1H), 10.60 (s, 1H).
[0188] N-Hydroxy-4-(9-adenenyl)-butyramide (4b)
[0189] Compound 4b was prepared by subjecting compound 3b to general procedure B. Yield=68%. TLC: R f =0.19 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >99% (HPLC method B). 1 H NMR (400 MHz, DMSO): δ2.05 (m, 2H), 2.15 (m, 2H), 4.25 (t, 2H), 7.30 (s, 2H), 8.25 (s, 2H), 8.85 (s, 1H), 10.50 (s, 1H).
[0190] N-Hydroxy -5-(9-adenenyl)-pentanamide (4c)
[0191] Compound 4c was prepared by subjecting compound 3c to general procedure B. Yield=74%. TLC: R f =0.24 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >90% (HPLC method A). 1 H NMR (400 MHz, DMSO): δ1.50 (m, 2H), 1.90 (m, 2H), 2.10 (t, 2H), 4.20 (t, 2H), 7.30 (s, 2H), 8.20 (s, 2H), 8.75 (s, 1H), 10.40 (s, 1H).
[0192] N-Hydroxy -6-(9-adenenyl)-hexanamide (4d)
[0193] Compound 4d was prepared by subjecting compound 3d to general procedure B. Yield=80%. TLC: R f =0.32 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >90% (HPLC method A). 1 H NMR (400 MHz, DMSO): δ1.30 (m, 2H), 1.60 (m, 2H), 1.90 (m, 2H), 2.00 (t, 2H), 4.20 (t, 2H), 7.30 (s, 2H), 8.20 (s, 2H), 8.75 (s, 1H), 10.40 (s, 1H).
[0194] N-Hydroxy -7-(9-adenenyl)-heptanamide (4e)
[0195] Compound 4e was prepared by subjecting compound 3e to general procedure B. Yield=93%. TLC: R f =0.42 (CDCl 3 /MeOH/H 2 O 150/45/5). Purity: >90% (HPLC method A). 1 H NMR (400 MHz, DMSO): δ1.30 (m, 4H), 1.55 (m, 2H), 1.90 (m, 2H), 2.00 (t, 2H), 4.20 (t, 2H), 7.30 (s, 2H), 8.20 (s, 2H), 8.75 (s, 1H), 10.40 (s, 1H).
[0196] 5-(9-Adenenyl)-pentanoic acid (5c)
[0197] Compound 5c was prepared by subjecting compound 3c to general procedure C. Yield=26%. Purity: >95% (HPLC method A). 1 H NMR (400 MHz, DMSO): δ1.50 (m, 2H), 1.90 (m, 2H), 2.35 (t, 2H), 4.20 (t, 2H), 7.30 (s, 2H), 8.21 (s, 1H), 8.22 (s, 1H), 12.2 (s, 1H).
[0198] 6-(9-Adenenyl)-hexanoic acid (5d)
[0199] Compound 5d was prepared by subjecting compound 3d to general procedure C. Yield=31%. Purity: >95% (HPLC method A). 1 H NMR (400 MHz, DMSO): δ1.35 (m, 2H), 1.60 (m, 2H), 1.90 (m, 2H), 2.30 (t, 2H), 4.20 (t, 2H), 7.30 (s, 2H), 8.21 (s, 1H), 8.22 (s, 1H), 12.2 (bs, 1H).
[0200] 7-(9-Adenenyl)-heptanoic acid (5e)
[0201] Compound 5e was prepared by subjecting compound 3e to general procedure C. Yield=31%. Purity: >95% (HPLC method A). 1 H NMR (400 MHz, DMSO): δ1.35 (m, 4H), 1.55 (m, 2H), 1.90 (m, 2H), 2.30 (t, 2H), 4.20 (t, 2H), 7.30 (s, 2H), 8.21 (s, 1H), 12.1 (s, 1H).
[0202] (1R, 3S)-1-Hydroxy-3-(methyl-carboxymethoxy)-4-cyclopentene (7)
[0203] (1R, 3S)-1-Acetoxy-3-hydroxy-4-cyclopentene was subjected to general procedure D. Yield=85%. TLC: R f =0.33 (25% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ1.25 (t, 3H), 1.75 (m, 1H), 2.05 (s, 3H), 2.75 (m, 1H), 4.10 (s, 2H), 4.20 (q, 2H), 4.55 (m, 1H), 5.45 (m, 1H), 6.00 (d, 1H), 6.15 (d, 1H). Subsequent subjection of the product to general procedure E gave compound 7. Yield=84%. TLC: R f =0.59 (EtOAc). 1H NMR (400 MHz, CDCl 3 ): δ1.70 (s, 2H), 2.65 (m, 1H), 3.75 (s, 3H), 4.10 (s, 2H), 4.45 (m, 1H), 4.65 (m, 1H), 6.05 (m, 2H).
[0204] (1S, 3S)-1-(9-Adenenyl)-3-(methyl-carboxymethoxy)-4-cyclopentene (8)
[0205] Compound 8 was prepared by subjecting compound 7 to general procedure F. Yield=17%. TLC: R f =0.16 (5% MeOH/CHCl 3 ). Purity: >93% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.45 (m, 2H), 3.80 (s, 3H), 4.35 (s, 2H), 5.10 (m, 1H), 5.85 (m, 1H), 6.25 (m, 1H), 6.45 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1H), 8.25 (s, 1H)
[0206] (1S, 3S)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethoxy)-4-cyclopentene (9)
[0207] Compound 9 was prepared by subjecting compound 8 to general procedure B. Yield=95%. TLC: R f =0.33 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >91% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.45 (m, 1H), 2.55 (m, 1H), 4.05 (s, 2H), 5.05 (m, 1H), 5.90 (m, 1H), 6.30 (m, 1H), 6.50 (m, 1H), 7.95 (bs, 2H), 8.25 (s, 1H), 8.35 (s, 1H), 8.95 (s, 1H), 10.70 (s, 1H).
[0208] (1S, 3S)-1-(9-Adenenyl)-3-carboxymethoxy-4-cyclopentene (10)
[0209] Compound 10 was prepared by subjecting compound 8 to general procedure C. Yield=52%. TLC: R f =0.07 (CHCl 3 /MeOH/H 2 O 150145/5). Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.45 (m, 2H), 4.10 (s, 2H), 5.10 (m, 1H), 5.85 (m, 1H), 6.25 (m, 1H), 6.45 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1H), 8.25 (s, 1H)
[0210] (1R, 3R)-1-(9-Adenenyl)-3-(methyl-carboxymethoxy)cyclopentane (11)
[0211] Compound 11 was prepared by subjecting compound 8 to general procedure G. Yield=85%. TLC: R f =0.33 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.90 (m, 1H), 2.10 (m, 1H), 2.35 (m, 4H), 3.80 (s, 3H), 4.25 (s, 2H), 4.35 (m, 1H), 5.10 (m, 1H), 7.30 (s, 2H), 8.20 (s, 1H), 8.35 (s, 1H).
[0212] (1R, 3R)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethoxy)cyclopentane (12)
[0213] Compound 12 was prepared by subjecting compound 11 to general procedure B. Yield=99%. TLC: R f =0.22 (5% MeOH/CHCl 3 ). Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.90 (m, 1H), 2.10 (m, 1H), 2.35 (m, 4H), 3.95 (s, 2H), 4.30 (m, 1H), 5.10 (m, 1H), 7.35 (s, 2H), 8.20 (s, 1H), 8.35 (s, 1H), 8.95 (s, 1H)
[0214] (1R, 3R)-1-(9-Adenenyl)-3-carboxymethoxycyclopentane (13)
[0215] Compound 13 was prepared by subjecting compound 11 to general procedure C. Yield=65%. TLC: R f =0.07 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.90 (m, 1H), 2.10 (m, 1H), 2.35 (m, 4H), 4.15 (s, 2H), 4.35 (m, 1H), 5.10 (m, 1H), 7.30 (s, 2H), 8.25 (s, 1H), 8.35 (s, 1H).
[0216] (1R, 3S)-1-Hydroxy-3-(tert-Butyl-dimethylsiloxy)-4-cyclopentene (14)
[0217] (1R, 3S)-1-Acetoxy-3-hydroxy-4-cyclopentene to general procedure H. Yield=100%. TLC: R f =0.48 (10% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ0.05 (s, 6H), 0.90 (s, 9H), 1.55 (m, 1H), 2.00 (s, 3H), 2.80 (m, 1H), 4.70 (m, 1H), 5.45 (m, 1), 5.85 (m, 1H), 5.95 (m, 1H). Subsequent subjection of the product to general procedure E gave compound 14. Yield=90%. TLC: R f =0.43 (25% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ0.05 (s, 6H), 0.90 (s, 9H), 1.50 (m, 1H), 2.65 (m, 1H), 4.55 (m, 1H), 4.65 (m, 1H), 5.85 (m, 1H), 5.95 (m, 1H).
[0218] (1S, 3R)-1-Hydroxy-3-(ethyl-carboxymethoxy)-4-cyclopentene (15)
[0219] Compound 14 was subjected to general procedure D. Yield=77%. TLC: R f =0.29 (10% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ0.05 (s, 6H), 0.90 (s, 9H), 1.25 (t, 3H), 1.60 (m, 1H), 2.65 (m, 1H), 4.10 (s, 2H), 4.20 (q, 2H), 4.55 (m, 1H), 4.65 (m, 1H), 5.95 ( m, 2H). Subsequent subjection of the product to general procedure I gave compound 15. Yield=79%. TLC: R f =0.65 (EtOAc). 1 H NMR (400 MHz, CDCl 3 ): δ1.25 (t, 3H), 1.65 (m, 1H), 1.75 (s, 1H), 2.65 (m, 1H), 4.10 (s, 2H), 4.20 (q, 2H), 4.45 (m, 1H), 4.65 (m, 1H), 6.05 (m, 2H).
[0220] (1R, 3R)-1-(9-Adenenyl)-3-(ethyl-carboxymethoxy)-4-cyclopentene (16)
[0221] Compound 16 was prepared by subjecting compound 15 to general procedure F. Yield=21%. TLC: R f =0.18 (5% MeOH/CHCl 3 ). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.35 (t, 3H), 2.45 (m, 2H), 4.25 (q, 2H), 4.35 (s, 2H), 5.10 (m, 1H), 5.85 (m, 1H), 6.25 (m, 1H), 6.45 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1H)
[0222] (1R, 3R)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethoxy)-4-cyclopentene (17)
[0223] Compound 17 was prepared by subjecting compound 16 to general procedure B. Yield=88%. TLC: R f =0.33 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.45 (m, 1H), 2.55 (m, 1H), 4.05 (s, 2H), 5.05 (m, 1H), 5.90 (m, 1H), 6.30 (m, 1H), 6.50 (m, 1H), 7.30 (bs, 2H), 8.10 (s, 1H), 8.20 (s, 1H), 8.95 (s, 1H), 10.70 (s, 1H).
[0224] (1R, 3R)-1-(9-Adenenyl)-3-carboxymethoxy-4-cyclopentene (18)
[0225] Compound 18 was prepared by subjecting compound 16 to general procedure C. Yield=70%. TLC: R f =0.07 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.45 (m, 2H), 4.10 (s, 2H), 5.10 (m, 1H), 5.85 (m, 1H), 6.25 (m, 1H), 6.45 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1H), 8.25 (s, 1H).
[0226] (1S, 3S)-1-(9-Adenenyl)-3-(ethyl-carboxymethoxy)cyclopentane (19)
[0227] Compound 19 was prepared by subjecting compound 16 to general procedure G. Yield=94%. TLC: R f =0.23 (CHCl 3 /MeOH/H2O 150/45/5). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.35 (t, 3H), 1.90 (m, 1H), 2.10 (m, 1H), 2.35 (m, 4H), 4.25 (s, 2H), 4.28 (q, 2H), 4.35 (m, 1H), 5.10 (m, 1H), 7.30 (s, 2H) 8.20 (s, 1H), 8.35 (s, 1H).
[0228] (1S, 3S)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethoxy)cyclopentane (20)
[0229] Compound 20 was prepared by subjecting compound 19 to general procedure B. Yield=90%. TLC: R f =0.36 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.90 (m, 1H), 2.10 (m, 1H), 2.35 (m, 4H), 3.95 (s, 2H), 4.30 (m, 1H), 5.10 (m, 1H), 7.35 (s, 2H), 8.20 (s, 1H), 8.35 (s, 1H), 8.95 (s, 1H), 10.65 (s, 1H).
[0230] (1S, 3S)-1-(9-Adenenyl)-3-carboxymethoxycyclopentane (21)
[0231] Compound 21 was prepared by subjecting compound 19 to general procedure C. Yield=100%. TLC: R f =0.07 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.90 (m, 1H), 2.10 (m, 1H), 2.35 (m, 4H), 4.15 (s, 2H), 4.35 (m, 1H), 5.10 (m, 1H), 7.30 (s, 2H), 8.25 (s, 1H), 8.35 (s, 1H).
[0232] (1R, 3R)-1-(tert-Butyl-dimethylsiloxy)-3-hydroxy-4-cyclopentene (22)
[0233] Compound 14 was subjected to general procedure J. Yield=81%. TLC: R f =0.50 (10% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ0.05 (s, 6H), 0.90 (s, 9H), 2.20 (m, 1H), 2.30 (m, 1H), 5.10 (s, 1H), 6.05 (m, 2H), 6.10 (m, 1H), 8.20 (d, 2H), 8.20 (d, 2H). Subsequent subjection of the product to general procedure E gave compound 22. Yield=85%. TLC: R f =0.33 (25% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ0.05 (s, 6H), 0.90 (s, 9H), 2.05 (m, 2H), 5.00 (m, 1H), 5.05 (m, 1H), 5.95 (m, 2H).
[0234] (1S, 3S)-1-Hydroxy-3-(ethyl-carboxymethoxy)-4-cyclopentene (23)
[0235] Compound 22 was subjected to general procedure D. Yield=71%. TLC: R f =0.33 (10% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ0.05 (s, 6H), 0.90 (s, 9H), 1.30 (t, 3H), 1.90 (m, 1H), 2.20 (m, 1H), 4.05 (s, 2H), 4.20 (q, 2H), 4.75 (m, 1H), 5.05 (m, 1H), 6.00 (m, 2H). Subsequent subjection of the product to general procedure K gave compound 23. Yield=91%. TLC: R f =0.25 (50% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ1.25 (t, 3H), 2.00 (m, 1H), 2.25 (m, 1H), 4.05 (s, 2H), 4.20 (q, 2H), 4.80 (m, 1H), 5.05 (m, 1H), 6.05 (m, 2H).
[0236] (1R, 3S)-1-(9-Adenenyl)-3-(ethyl-carboxymethoxy)-4-cyclopentene (24)
[0237] Compound 24 was prepared by subjecting compound 23 to general procedure F. Yield=13%. TLC: R f =0.21 (5% MeOH/CHCl 3 ). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.30 (t, 3H), 2.05 (m, 1H), 3.00 (m, 1H), 4.25 (q, 2H), 4.35 (s, 2H), 4.80 (m, 1H), 5.60 (m, 1H), 6.30 (m, 1H), 6.45 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1H), 8.25 (s, 1H).
[0238] (1R, 3S)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethoxy)-4-cyclopentene (25)
[0239] Compound 25 was prepared by subjecting compound 24 to general procedure B. Yield=88%. TLC: R f =0.32 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >90% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.05 (m, 1H), 3.00 (m, 1H), 4.10 (s, 2H), 4.75 (m, 1H), 5.60 (m, 1H), 6.25 (m, 1H), 6.45 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1H), 8.25 (s, 1H), 8.95 (s, 1H), 10.70 (s, 1H).
[0240] (1R, 3S)-1-(9-Adenenyl)-3-carboxymethoxy-4-cyclopentene (26)
[0241] Compound 26 was prepared by subjecting compound 24 to general procedure C. Yield=100%. TLC: R f =0.07 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >75% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.00 (m, 1H), 2.95 (m, 1H), 3.90 (s, 2H), 4.75 (m, 1H), 5.55 (m, 1H), 6.20 (m, 1H), 6.45 (m, 1H), 7.30 (s, 2H), 8.10 (s, 1H), 8.15 (s, 1H).
[0242] (1S, 3R)-1-(9-Adenenyl)-3-(ethyl-carboxymethoxy)cyclopentane (27)
[0243] Compound 27 was prepared by subjecting compound 24 to general procedure G. Yield=89%. TLC: R f =0.18 (5% MeOH/CHCl 3 ). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.35 (t, 3H), 1.95 (m, 1H), 2.10 (m, 1H), 2.15 (m, 2H), 2.35 (m, 1H), 2.60 (m, 1H), 4.25 (m, 5H), 5.05 (m, 1H), 7.30 (s, 2H), 8.25 (s, 1H), 8.35 (s, 1H).
[0244] (1S, 3R)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethoxy)cyclopentane (28)
[0245] Compound 28 was prepared by subjecting compound 27 to general procedure B. Yield=86%. TLC: R f =0.35 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.90 (m, 1H), 2.10 (m, 1H), 2.20 (m, 3H), 2.60 (m, 1H), 3.95 (s, 2H), 4.20 (m, 1H), 5.00 (m, 1H), 7.30 (s, 2H), 8.20 (s, 1H), 8.35 (s, 1H), 8.95 (s, 1H), 10.65 (s, 1H).
[0246] (1S, 3R)-1-(9-Adenenyl)-3-carboxymethoxycyclopentane (29)
[0247] Compound 29 was prepared by subjecting compound 27 to general procedure C. Yield=100%. TLC: R f =0.11 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >90% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.90 (m, 1H), 2.10 (m, 1H), 2.15 (m, 2H), 2.30 (m, 1H), 2.55 (m, 1H), 4.00 (s, 2H), 4.25 (m, 1H), 5.00 (m, 1H), 7.30 (s, 2H), 8.25 (s, 1H), 8.50 (s, 1H).
[0248] (1R, 3R)-1-Hydroxy-3-(methyl-carboxymethoxy)-4-cyclopentene (30)
[0249] Compound 15 was subjected to general procedure J. Yield=89%. TLC: R f =0.31 (25% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ1.30 (t, 3H), 2.35 (m, 2H), 4.10 (s, 2H), 4.25 (q, 2H), 4.90 (m, 1H), 6.05 (m, 1H), 6.20 (m, 1H), 6.30 (m, 1H), 8.20 (d, 2H), 8.30 (d, 2H). Subsequent subjection of the product to general procedure E gave compound 30. Yield=91%. TLC: R f =0.18 (50% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ2.00 (m, 1H), 2.25 (m, 1H), 3.75 (s, 3H), 4.05 (s, 2H), 4.80 (m, 1H), 5.05 (m, 1H), 6.05 (s, 2H).
[0250] (1S, 3R)-1-(9-Adenenyl)-3-(methyl-carboxymethoxy)-4-cyclopentene (31)
[0251] Compound 31 was prepared by subjecting compound 30 to general procedure F. Yield=16%. TLC: R f =0.14 (5% MeOH/CHCl 3 ). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.05 (m, 1H), 3.00 (m, 1H), 3.75 (s, 3H), 4.35 (s, 2H), 4.80 (m, 1H), 5.60 (m, 1H), 6.30 (m, 1H), 6.45 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1H), 8.25 (s, 1H).
[0252] (1S, 3R)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethoxy)-4-cyclopentene (32)
[0253] Compound 32 was prepared by subjecting compound 31 to general procedure B. Yield=100%. TLC: R f =0.32 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.05 (m, 1H), 3.00 (m, 1H), 4.10 (s, 2H), 4.75 (m, 1H), 5.60 (m, 1H), 6.25 (m, 1H), 6.45 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1H) 8.95 (s, 1H), 10.70 (s, 1H).
[0254] (1S, 3R)-1-(9-Adenenyl)-3-carboxymethoxy-4-cyclopentene (33)
[0255] Compound 33 was prepared by subjecting compound 31 to general procedure C. Yield=88%. TLC: R f =0.07 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.00 (m, 1H), 2.95 (m, 1H), 4.15 (s, 2H), 4.75 (m, 1H), 5.60 (m, 1H), 6.25 (m, 1H), 6.45 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1H), 8.25 (s, 1H).
[0256] (1R, 3S)-1-(9-Adenenyl)-3-(methyl-carboxymethoxy)cyclopentane (34)
[0257] Compound 34 was prepared by subjecting compound 31 to general procedure G. Yield=95%. TLC: R f =0.24 (5% MeOH/CHCl 3 ). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.95 (m, 1H), 2.10 (m, 1H), 2.15 (m, 2H), 2.35 (m, 1H), 2.60 (m, 1H), 3.80 (s, 3H), 4.25 (m, 1H), 4.30 (s, 2H), 5.05 (m, 1H), 7.30 (s, 2H) 8.25 (s, 1H), 8.35 (s, 1H).
[0258] (1R, 3S)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethoxy)cyclopentane (35)
[0259] Compound 35 was prepared by subjecting compound 34 to general procedure B. Yield=87%. TLC: R f =0.34 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >90% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.90 (m, 1H), 2.10 (m, 1H), 2.20 (m, 3H), 2.60 (m, 1H), 3.95 (s, 2H), 4.20 (m, 1H), 5.00,(m, 1H), 7.30 (s, 2H), 8.20 (s, 1H), 8.35 (s, 1H), 9.00 (s, 1H), 10.70 (s, 1H).
[0260] (1R, 3S)-1-(9-Adenenyl)-3-carboxymethoxycyclopentane (36)
[0261] Compound 36 was prepared by subjecting compound 34 to general procedure C. Yield=95%. TLC: R f =0.08 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >85% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.90 (m, 1H), 2.10 (m, 1H), 2.15 (m, 2H), 2.30 (m, 1H), 2.55 (m, 1H), 3.90 (s, 2H), 4.25 (m, 1H), 5.00 (m, 1H), 7.30 (s, 2H), 8.25 (s, 1H), 8.60 (s, 1H).
[0262] (1S, 3R)-1-Hydroxy-3-triphenylmethoxy-4-cyclopentene (37)
[0263] Compound 14 was subjected to general procedure O. TLC: R f =0.27 (Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ0.00 (s, 6H), 1.85 (s, 9H), 1.55 (m, 1H), 2.15 (m, 1H), 4.35 (m, 2H), 4.95 (m, 1H), 5.60 (m, 1H), 7.20 (m, 3H), 7,25 (m, 6H), 7.50 (d, 6H). Subsequent subjection of the product to general procedure K gave compound 37. Yield=87% (2 steps). TLC: R f =0.32 (25% EtOAc/Hexane). 1H NMR (400 MHz, CDCl 3 ): δ1.40 (m, 1H), 2.20 (m, 1H), 4.35 (m, 1H), 4.45 (m, 1H), 5.15 (m, 1H), 5.75 (m, 1H), 7.20 (m, 3H), 7,25 (t, 6H), 7.50 (d, 6H).
[0264] (1R, 3R)-1-Chloro-3-triphenylmethoxy-4-cyclopentene (38)
[0265] Compound 38 was prepared by subjecting compound 37 to general procedure L. Yield=84%. TLC: R f =0.61 (10% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ2.00 (m, 1H), 2.15 (m, 1H), 4.95 (m, 2H), 5.15 (m, 1H), 5.80 (m, 1H), 7.20 (m, 3H) 7.25 (t, 6H), 7.50 (d, 6H).
[0266] (1S, 3R)-1-(2-Dimethylmalonyl)-3-triphenylmethoxy-4-cyclopentene (39)
[0267] Compound 39 was prepared by subjecting compound 38 to general procedure M. Yield=72%. TLC: R f =0.27 (10% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ1.35 (m, 1H), 2.05 (m, 1H), 3.00 (m, 1H), 3.30 (d, 1H), 3.70 (s, 6H), 4.60 (m, 1H) 4.90 (m 1H), 5.60 (m, 1H), 7.20 (m, 3H), 7.25 (t, 6H), 7.45 (d, 6H).
[0268] (1R, 3R)-1-Hydroxy-3-(methyl-carboxymethyl)-4-cyclopentene (40)
[0269] Compound 39 was subjected to general procedure N. Yield=80%. TLC: R f =0.45 (10% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ1.30 (m, 1H), 2.10 (m, 1H), 2.35 (m, 1H), 2.45 (m, 1H), 2.75 (m, 1H), 3.65 (s, 3H), 4.60 (m, 1H), 4.85 (m, 1H), 5.60 (m, 1H), 7.20 (m, 3H), 7.25 (t, 6H), 7.45 (d, 6H). Subsequent subjection of the product to general procedure P gave compound 40. Yield=39%. TLC: R f =0.38 (50% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ1.40 (m, 1H), 2.45 (m, 2H), 2.55 (m, 1H), 2.95 (m, 1H), 3.65 (s, 3H), 4.80 (m, 1H), 5.85 (m, 2H).
[0270] (1S, 3R)-1-(9-Adenenyl)-3-(methyl-carboxymethyl)-4-cyclopentene (41)
[0271] Compound 41 was prepared by subjecting compound 40 to general procedure F. Yield=9%. TLC: R f =0.22 (5% MeOH/CHCl 3 ). Purity: >85% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.30 (m, 2H), 2.60 (m, 2H), 3.50 (m, 1H), 3.75 (s, 3H), 5.75 (m, 1H), 6.05 (m, 1H), 6.30 (m, 1H), 7.40 (s, 2H), 8.10 (s, 1H), 8.25 (s, 1H)
[0272] (1S, 3R)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethyl)-4-cyclopentene (42)
[0273] Compound 42 was prepared by subjecting compound 41 to general procedure B. Yield=37%. TLC: R f =0.40 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >97% (HPLC method C). 1H NMR (400 MHz, DMSO): δ2.20 (m, 2H), 2.30 (m, 2H), 5.70 (m, 1H), 6.00 (m, 1H), 6.30 (m, 1H), 7.30 (s, 2H), 8.10 (s, 1H), 8.25 (s, 1H), 8.90 (s, 1H), 10.55 (s, 1H).
[0274] (1S, 3R)-1-(9-Adenenyl)-3-carboxymethyl-4-cyclopentene (43)
[0275] Compound 43 was prepared by subjecting compound 41 to general procedure C. Yield=97%. TLC: R f =0.42 (CHCl 3 /MeOH/H 2 O 150/455). Purity: >86% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.20-2.40 (m, 4H), 3.45 (m, 1H), 5.70 (m, 1H), 6.00 (m, 1H), 6.30 (m, 1H), 7.30 (s, 2H), 8.10 (s, 1H), 8.20 (s, 1H).
[0276] (1R, 3R)-1-(9-Adenenyl)-3-(methyl-carboxymethyl)cyclopentane (44)
[0277] Compound 44 was prepared by subjecting compound 41 to general procedure G. Yield=95%. TLC: R f =0.21 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >86% (HPLC method C). 1H NMR (400 MHz, DMSO): δ1.45 (m, 1H), 1.95 (m, 1H), 2.20 (m, 2H), 2.30 (m, 2H), 2.55 (d, 2H), 2.75 (m, 1H), 3.75 (s, 3H), 5.05 (m, 1H), 7.35 (s, 2H), 8.25 (s, 1H), 8.35 (s, 1H).
[0278] (1R, 3R)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethyl)cyclopentane (45)
[0279] Compound 45 was prepared by subjecting compound 44 to general procedure B. Yield=39%. TLC: R f =0.34 (CHCl 3 /MeOH/H 2 O 150/455). Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.45 (m, 1H), 1.95 (m, 1H), 2.15 (d, 2H), 2.20 (m, 3H), 2.35 (m, 1H), 2.70 (m, 1H), 5.05 (m, 1H), 7.30 (s, 2H), 8.25 (s, 1H) 8.35 (s, 1H), 8.85 (s, 1H), 10.50 (s, 1H).
[0280] (1R, 3R)-1-(9-Adenenyl)-3-carboxymethylcyclopentane (46)
[0281] Compound 46 was prepared by subjecting compound 44 to general procedure C. Yield=83%. TLC: R f =0.38 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >80% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.45 (m, 1H), 1.95 (m, 1H), 2.15-2.40 (m, 4H), 2.45 (d, 2H), 2.70 (m, 1H), 5.05 (m, 1H), 7.30 (s, 2H), 8.25 (s, 1H), 8.35 (s, 1H).
[0282] (1S, 3S)-1-Chloro-3-(tert-Butyl-dimethylsiloxy)-4-cyclopentene (47)
[0283] Compound 47 was prepared by subjecting compound 14 to general procedure L. Yield=79%. TLC: R f =0.80 (10% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ0.10 (s, 6H), 0.90 (s, 9H), 2.15 (m, 1H), 2.50 (m, 1H), 5.05 (m, 1H), 5.15 (m, 1H), 5.95 (m, 2H).
[0284] (1R, 3S)-1-(2-Dimethylmalonyl)-3-(tert-Butyl-dimethylsiloxy)-4-cyclopentene (48)
[0285] Compound 48 was prepared by subjecting compound 47 to general procedure M. Yield=74%. TLC: R f =0.32 (10% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ0.10 (s, 6H), 0.90 (s, 9H), 1.40 (m, 1H), 2.40 (m, 1H), 3.20 (m, 1H), 3.35 (m, 1H) 3.75 (s, 6), 4.80 (m, 1H), 5.80 (m, 2H).
[0286] (1S, 3S)-1-Hydroxy-3-(methyl-carboxymethyl)-4-cyclopentene (49)
[0287] Compound 48 was subjected to general procedure N. Yield=75%. TLC: R f =0.57 (10% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ0.05 (s, 6H), 0.90 (s, 9H), 1.30 (m, 1H), 2.35 (m, 1H), 2.45 (m, 2H), 2.90 (m, 1H), 3.65 (s, 3H), 4.80 (m, 1H), 5.75 (m, 1H), 5.80 (m, 1H). Subsequent subjection of the product to general procedure I gave compound 49. Yield=61%. TLC: R f =0.39 (50% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ1.40 (m, 1H), 2.25 (m, 2H), 2.35 (m, 1H), 2.95 (m, 1H), 3.65 (s, 3H), 4.80 (m, 1H), 5.85 (m, 2H).
[0288] (1R, 3S)-1-(9-Adenenyl)-3-(methyl-carboxymethyl)-4-cyclopentene (50)
[0289] Compound 50 was prepared by subjecting compound 49 to general procedure F. Yield=10%. TLC: R f =0.14 (5% MeOH/CHCl 3 ). Purity: >85% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.30 (m, 2H), 2.60 (m, 2H), 3.75 (s, 3H), 5.75 (m, 1H), 6.05 (m, 1H), 6.30 (m, 1H), 7.30 (s, 2H), 8.10 (s, 1H), 8.25 (s, 1H).
[0290] (1R, 3S)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethyl)-4-cyclopentene (51)
[0291] Compound 51 was prepared by subjecting compound 50 to general procedure B. Yield=63%. TLC: R f =0.40 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >90% (HPLC method C). 1H NMR (400 MHz, DMSO): δ2.20 (m, 2H), 2.30 (m, 2H), 5.70 (m, 1H), 6.00 (m, 1H), 6.30 (m, 1H), 7.30 (s, 2H), 8.10 (s, 1H), 8.25 (s, 1H), 9.10 (s, 1H), 10.60 (s, 1H).
[0292] (1R, 3S)-1-(9-Adenenyl)-3-carboxymethyl-4-cyclopentene (52)
[0293] Compound 52 was prepared by subjecting compound 50 to general procedure C. Yield=100%. TLC: R f =0.31 (CHCl 3 /MeOH/H 2 O 150/455). Purity: >85% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.20-2.40 (m, 4H), 4.15 (m, 1H), 5.70 (m, 1H), 5.95 (m, 1H), 6.30 (m, 1H), 7.30 (s, 2H), 8.10 (s, 1H), 8.20 (s, 1H).
[0294] (1S, 3S)-1-(9-Adenenyl)-3-(methyl-carboxymethyl)cyclopentane (53)
[0295] Compound 53 was prepared by subjecting compound 50 to general procedure G. Yield=93%. TLC: R f =0.22 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >93% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.45 (m, 1H), 1.95 (m, 1H), 2.20 (m, 2H), 2.30 (m, 2H), 2.55 (d, 2H), 2.75 (m, 1H), 3.75 (s, 3H), 5.05 (m, 1H), 7.35 (s, 2H), 8.25 (s, 1H), 8.35 (s, 1H).
[0296] (1S, 3S)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethyl)cyclopentane (54)
[0297] Compound 54 was prepared by subjecting compound 53 to general procedure B. Yield=34%. TLC: R f =0.39 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >85% (HPLC method C). 1H NMR (400 MHz, DMSO): δ1.45 (m, 1H), 1.95 (m, 1H), 2.15 (d, 2H), 2.20 (m, 3H), 2.35 (m, 1H), 2.70 (m, 1H), 5.05 (m, 1H), 7.30 (s, 2H), 8.15 (s, 1H), 8.35 (s, 1H), 8.85 (s, 1H), 10.50 (s, 1H).
[0298] (1S, 3S)-1-(9-Adenenyl)-3-carboxymethylcyclopentane (55)
[0299] Compound 55 was prepared by subjecting compound 53 to general procedure C. Yield=83%. TLC: R f =0.33 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >80% (BPLC method C). 1 H NMR (400 MHz, DMSO): δ1.45 (m, 1H), 1.95 (m, 1H), 2.15-2.40 (m, 4H), 2.45 (d, 2H), 2.70 (m, 1H), 5.05 (m, 1H), 7.30 (s, 2H), 8.25 (s, 1H), 8.35 (s, 1H).
[0300] (1R, 3S)-1-Chloro-3-(tert-Butyl-dimethylsiloxy)-4-cyclopentene (56)
[0301] Compound 56 was prepared by subjecting compound 22 to general procedure L. Yield=99%. TLC: R f =0.86 (10% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ0.10 (s, 6H), 0.90 (s, 9H), 1.95 (m, 1H), 2.90 (m, 1H), 4.75 (m, 2H), 5.90 (m, 2H)
[0302] (1S, 3S)-1-(2-Dimethylmalonyl)-3-(tert-Butyl-dimethylsiloxy)-4-cyclopentene (57)
[0303] Compound 57 was prepared by subjecting compound 56 to general procedure M. Yield=75%. TLC: R f =0.36 (10% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ0.05 (s, 6H), 0.90 (s, 9H), 1.95 (m, 2H), 3.20 (d, 1H), 3.55 (m, 1H), 3.75 (s, 6H), 4.90 (m, 1H), 5.80 (m, 2H).
[0304] (1S, 3R)-1-Hydroxy-3-(methyl-carboxymethyl)-4-cyclopentene (58)
[0305] Compound 57 was subjected to general procedure N. Yield=74%. TLC: R f =0.58 (10% EtOAc/Hexane). 1 H NMR (400 MHz, DMSO): δ0.20 (s, 6H), 0.95 (s, 9H), 1.80 (m, 1H), 1.95 (m, 1H), 2.40 (m, 1H), 2.45 (m, 1H), 3.20 (m, 1H), 3.70 (s, 3H), 500 (m, 1H), 5.85 (m, 1H), 5.95 (m, 1H). Subsequent subjection of the product to general procedure K gave compound 58. Yield=59%. TLC: R f =0.40 (50% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ1.85 (m, 1H), 2.00 (m, 1H), 2.35 (m, 2H), 3.30 (m, 1H), 3.65 (s, 3H), 4.90 (m, 1H), 5.85 (m, 1H), 5.95 (m, 1H).
[0306] (1R, 3R)-1-(9-Adenenyl)-3-(methyl-carboxymethyl)-4-cyclopentene (59)
[0307] Compound 59 was prepared by subjecting compound 58 to general procedure F. Yield=4.3%. TLC: R f =0.17 (5% MeOH/CHCl 3 ). Purity: >81% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.75 (m, 1H), 2.62 (m, 1H), 2.75 (m, 1H), 2.95 (m, 1H), 3.25 (m, 1H), 3.75 (s, 3H), 5.70 (m, 1H), 6.05 (m, 1H), 6.20 (m, 1H), 7.35 (s, 2H), 8.20 (s, 1H), 8.25 (s, 1H).
[0308] (1R, 3R)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethyl)-4-cyclopentene (60) and (1R, 3R)-1-(9-Adenenyl)-3-carboxymethyl-4-cyclopentene (61)
[0309] Compound 59 was subjected to general procedure B and the products were separated by preparative TLC (CHCl 3 /MeOH/H 2 O 150/45/5). Hydroxamic acid (60): Yield=21%. TLC: R f =0.29 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >90% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.75 (m, 1H), 2.20 (m, 1H), 2.35 (m, 1H), 2.90 (m, 1H), 3.25 (m, 1H), 5.70 (m, 1H), 6.05 (m, 1H), 6.20 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1H), 8.25 (s, 1H), 9.10 (s, 1H), 10.60 (s, 1H). Carboxylic acid (61): Yield=31%. TLC: R f =0.25 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.70 (m, 1H), 2.20 (m, 1H), 2.30 (m, 1H), 2.90 (m, 1H), 3.20 (m, 1H), 5.65 (m, 1H), 6.00 (m, 1H), 6.35 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1H), 8.25 (s, 1H).
[0310] (1S, 3R)-1-(9-Adenenyl)-3-(methyl-carboxymethyl)cyclopentane (62)
[0311] Compound 62 was prepared by subjecting compound 59 to general procedure G. Yield=85%. TLC: R f =0.27 (5% MeOH/CHCl 3 ). 1 H NMR (400 MHz, DMSO): δ1.72 (m, 1H), 1.88 (m, 1H), 2.04 (m, 1H), 2.16 (m, 1H), 2.28 (m, 1H), 2.46 (m, 2H), 3.70 (s, 3H), 4.95 (m, 1H), 7.30 (s, 2H), 8.25 (s, 1H), 8.35 (s, 1H).
[0312] (1S, 3R)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethyl)cyclopentane (63) and (1S, 3R)-1-(9-Adenenyl)-3-carboxymethylcyclopentane (64)
[0313] Compound 62 was subjected to general procedure B and the products were separated by preparative HPLC and isolated as TFA salts. Hydroxamic acid (63): Yield=32%. TLC: R f =0.33 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >90% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.70 (m, 1H), 1.85 (m, 1H), 2.00 (m, 1H), 2.20 (m, 1H), 2.25 (m, 2H), 2.30 (m, 1H), 2.45 (m, 2H), 5.00 (m, 1H), 8.45 (s, 1H), 8.55 (s, 1H). Carboxylic acid (64): Yield=11%. TLC: R f =0.33 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.70 (m, 1H), 1.85 (m, 1H), 2.05 (m, 1H), 2.15 (m, 1H), 2.30 (m, 1H), 2.45 (m, 1H), 2.50 (m, 3H), 5.05 (m, 1H), 8.50 (s, 1H), 8.60 (s, 1H).
[0314] (1R, 3R)-1-Hydroxy-3-triphenylmethoxy-4-cyclopentene (65)
[0315] Compound 37 was subjected to general procedure J. TLC: R f =0.36 (10% EtOAc/Hexane). 1H NMR (400 MHz, DMSO): δ2.00 (m, 1H), 2.15 (m, 1H), 4.95 (m, 1H), 5.40 (m, 1H), 5.95 (m, 1H), 6.05 (m, 1H), 7.30-7.60 (m, 15H), 8.20 (d, 2H), 8.40 (d, 2H). Subsequent subjection of the product to general procedure E gave compound 65. Yield=77% (2 steps). TLC: R f =0.32 (25% EtOAc/Hexane). 1 H NMR (400 MHz, DMSO): δ1.55 (m, 1H), 1.80 (m, 1H), 4.70 (m, 1H), 4.80 (m, 1H), 5.10 (m, 1H), 5.80 (m, 1H), 7.40 (m, 3H), 7.45 (m, 6H), 7.55 (m, 6H).
[0316] (1S, 3R)-1-Chloro-3-triphenylmethoxy-4-cyclopentene (66)
[0317] Compound 66 was prepared by subjecting compound 65 to general procedure L. Yield=93%. TLC: R f =0.58 (10% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ1.90 (m, 1H), 2.40 (m, 1H), 4.55 (m, 2H), 5.20 (m, 1H), 5.75 (m, 1H), 7.20 (m, 3H), 7.25 (t, 6H), 7.50 (d, 6H).
[0318] (1R, 3R)-1-(2-Dimethylmalonyl)-3-triphenylmethoxy-4-cyclopentene (67)
[0319] Compound 67 was prepared by subjecting compound 66 to general procedure M. Yield=74%. TLC: R f =0.22 (10% EtOAc/Hexane). 1 H NMR (400 MHz, DMSO): δ1.60 (m, 1H), 1.80 (m, 1H), 3.70 (s, 3H), 3.71 (s, 3H), 4.70 (m, 1H), 5.00 (m, 1H), 5.75 (m, 1H), 7.40 (m, 3H), 7.45 (t, 6H), 7.55 (d, 6H).
[0320] (1R, 3S)-1-Hydroxy-3-(methyl-carboxymethyl)-4-cyclopentene (68)
[0321] Compound 67 was subjected to general procedure N. Yield=63%. TLC: R f =0.45 (10% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ1.45 (m, 1H), 1.90 (m, 1H), 2.15 (m, 2H), 3.15 (m, 1H), 3.60 (s, 3H), 4.70 (m, 1H), 4.80 (m, 1H), 5.70 (m, 1H), 7.20 (m, 3H), 7.25 (t, 6H), 7.45 (d, 6H). Subsequent subjection of the product to general procedure P gave compound 68. Yield=54%. TLC: R f =0.35 (50% EtOAc/Hexane). 1 H NMR (400 MHz, CDCl 3 ): δ1.40 (m, 1H), 1.85 (m, 1H), 2.00 (m, 1H), 2.35 (m, 2H), 3.30 (m, 1H), 3.65 (s, 3H), 4.85 (m, 1H), 5.85 (m, 1H), 5.95 (m, 1H).
[0322] (1S, 3S)-1-(9-Adenenyl)-3-(methyl-carboxymethyl)-4-cyclopentene (69)
[0323] Compound 69 was prepared by subjecting compound 68 to general procedure F. Yield=16%. TLC: R f =0.17 (5% MeOH/CHCl 3 ). Purity: >87% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.75 (m, 1H), 2.62 (m, 1H), 2.75 (m, 1H), 2.95 (m, 1H), 3.25 (m, 1H), 3.75 (s, 3H), 5.70 (m, 1H), 6.05 (m, 1H), 6.20 (m, 1H), 7.35 (s, 2H) 8.20 (s, 1H), 8.25 (s, 1H).
[0324] (1S, 3S)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethyl)-4-cyclopentene (70)
[0325] Compound 70 was prepared by subjecting compound 69 to general procedure B. Yield=49%. TLC: R f =0.36 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >89% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.75 (m, 1H), 2.20 (m, 1H), 2.35 (m, 1H), 2.90 (m, 1H), 3.25 (m, 1H), 5.70 (m, 1H), 6.05 (m, 1H), 6.20 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1H), 8.25 (s, 1H), 8.90 (s, 1H), 10.50 (s, 1H).
[0326] (1S, 3S)-1-(9-Adenenyl)-3-carboxymethyl-4-cyclopentene (71)
[0327] Compound 71 was prepared by subjecting compound 69 to general procedure C. Yield=75%. TLC: R f =0.34 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >84% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.70 (m, 1H), 2.30 (m, 1H), 2.45 (m, 1H), 2.90 (m, 1H), 3.20 (m, 1H), 5.65 (m, 1H), 6.00 (m, 1H), 6.25 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1H), 8.25 (s, 1H).
[0328] (1R, 3S)-1-(9-Adenenyl)-3-(methyl-carboxymethyl)cyclopentane (72)
[0329] Compound 72 was prepared by subjecting compound 69 to general procedure G. Yield=92%. TLC: R f =0.27 (5% MeOH/CHCl 3 ). Purity: >87% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.72 (m, 1H), 1.88 (m, 1H), 2.04 (m, 1), 2.16 (m, 1H), 2.28 (m, 1H), 2.46 (m, 2H), 2.62 (m, 2H), 3.70 (s, 3H), 4.95 (m, 1H), 7.30 (s, 2H) 8.25 (s, 1H), 8.35 (s, 1H).
[0330] (1R, 3S)-1-(9-Adenenyl)-3-(N-hydroxycarbamoylmethyl)cyclopentane (73)
[0331] Compound 73 was prepared by subjecting compound 72 to general procedure B. Yield=56%. TLC: R f =0.42 (CHCl 3 /MeOH/H2O 150/45/5). Purity: >94% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.70 (m, 1H), 1.85 (m, 1H), 2.00 (m, 1H), 2.20 (m, 1H), 2.25 (m, 2H), 2.30 (m, 1H), 2.45 (m, 2H), 4.95 (m, 1H), 7.30 (s, 2H), 8.25 (s, 1H), 8.35 (s, 1H), 8.85 (bs, 1H), 10.50 (bs, 1H).
[0332] (1R, 3S)-1-(9-Adenenyl)-3-carboxymethylcyclopentane (74)
[0333] Compound 74 was prepared by subjecting compound 72 to general procedure C. Yield=99%. TLC: R f =0.42 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >82% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.70 (m, 1H), 1.85 (m, 1H), 2.05 (m, 1H), 2.15 (m, 1H), 2.30 (m, 1H), 2.45 (m, 4H), 4.95 (m, 1H), 7.35 (s, 2H), 8.20 (s, 1H), 8.35 (s, 1H).
[0334] (1S, 3R)-Methyl-1-aminocyclopent-4-ene-3-carboxylate hydrochloride (76a)
[0335] Compound 76a was prepared by subjecting (1S, 3R)-1-aminocyclopent-4-ene-3-carboxylic acid to general procedure Q. Yield=100%. 1 H NMR (400 MHz, DMSO): δ2.05 (m, 1H), 2.65 (m, 1H), 3.80 (s, 3H), 3.85 (m, 1H), 4.30 (m, 1H), 6.00 (m, 1H), 6.20 (m, 1H), 8.40 (bs, 3H).
[0336] (1R, 3S)-Methyl-1-aminocyclopent-4-ene-3-carboxylate hydrochloride (76b)
[0337] Compound 76b was prepared by subjecting (1R, 35)-1-aminocyclopent-4-ene-3-carboxylic acid to general procedure Q. Yield=100%. 1 H NMR (400 MHz, DMSO): δ2.05 (m 1H), 2.65 (m, 1H), 3.80 (s, 3H), 3.85 (m, 1H), 4.30 (m, 1H), 6.00 (m, 1H), 6.20 (m, 1H), 8.40 (bs, 3H).
[0338] (1S, 3R)-1-[9-(1-Chloroadenenyl)]-3-methylcarboxy-4cyclopentene (77a)
[0339] Compound 76a was subjected to general procedure R. Subsequent subjection of the crude product to general procedure S yielded the desired crude aminopyrimidine. Without purification, the crude aminopyrimidine was subjected to general procedure T giving compound 77a. Yield=40% (3 steps). TLC: R f =0.50% (EtOAc/Hexane). Purity: >90% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.35 (m, 1H), 3.00 (m, 1H), 3.80 (s, 3H), 3.95 (m, 1H), 5.90 (m, 1H), 6.25 (m, 1H), 6.40 (m, 1H), 8.65 (s, 1H), 8.90 (s, 1H).
[0340] (1R, 3S)-1-[9-(1-Chloroadenenyl)]-3-methylcarboxy-4-cyclopentene (77b)
[0341] Compound 76b was subjected to general procedure R. Subsequent subjection of the crude product to general procedure S yielded the desired crude arinopyrimidine. Without purification, the crude aminopyrimidine was subjected to general procedure T giving compound 77b. Yield=38% (3 steps). TLC: R f =0.50% (EtOAc/Hexane). Purity: >90% (HPLC method C). 2 H NMR (400 MHz, DMSO): δ2.35 (m, 1H), 3.00 (m, 1H), 3.80 (s, 3H), 3.95 (m, 1H), 5.90 (m, 1H), 6.25 (m, 1H), 6.40 (m, 1H), 8.65 (s, 1H), 8.90 (s, 1H).
[0342] (1S, 3R)-1-[9-(1-Azidoadenenyl)]-3-methylcarboxy-4-cyclopentene (78a)
[0343] Compound 78a was prepared by subjecting compound 77a to general procedure U. Yield=52%. Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.40 (m, 1H), 3.05 (m, 1H), 3.80 (s, 3H), 4.00 (m, 1H), 6.00 (m, 1H), 6.30 (m, 1H), 6.45 (m, 1H), 8.60 (m, 1H), 10.25 (s, 1H).
[0344] (1R, 3S)-1-[9-(1-Azidoadenenyl)]-3-methylcarboxy-4-cyclopentene (78b)
[0345] Compound 78b was prepared by subjecting compound 77b to general procedure U. Yield=60%. Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.40 (m, 1H), 3.05 (m, 1H), 3.80 (s, 3H), 4.00 (m, 1H), 6.00 (m, 1H), 6.30 (m, 1H), 6.45 (m, 1H), 8.60 (m, 1H), 10.25 (s, 1H).
[0346] (1R, 3S)-1-(9-Adenenyl)-3-methylcarboxycyclopentane (79a)
[0347] Compound 79a was prepared by subjecting compound 78a to general procedure G. Yield=99%. Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.20 (m, 3H), 2.30 (m, 1H), 2.40 (m, 1H), 2.55 (m, 1H), 3.15 (m, 1H), 3.80 (s, 3H), 5.00 (m, 1H), 7.35 (s, 2H), 8.20 (m, 1H), 8.35 (s, 1H).
[0348] (1S, 3R)-1-(9-Adenenyl)-3-methylcarboxycyclopentane (79b)
[0349] Compound 79b was prepared by subjecting compound 78b to general procedure G. Yield=96%. Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.20 (m, 3H), 2.30 (m, 1H), 2.40 (m, 1H), 2.55 (m, 1H), 3.15 (m, 1H), 3.80 (s, 3H), 5.00 (m, 1H), 7.35 (s, 2H), 8.20 (m, 1H), 8.35 (s, 1H).
[0350] (1R, 3S)-1-(9-Adenenyl)-3-(N-hydroxycarbamoyl)cyclopentane (80a)
[0351] Compound 80a was prepared by subjecting compound 79a to general procedure B. Yield=53%. Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.00 (m, 2H), 2.30 (m, 3H), 2.50 (m, 1H), 2.80 (m, 1H), 5.00 (m, 1H), 7.35 (s, 2H), 8.25 (m, 1H), 8.45 (s, 1H), 8.95 (s, 1H), 10.65 (s, 1H).
[0352] (1S, 3R)-1-(9-Adenenyl)-3-(N-hydroxycarbamoyl)cyclopentane (80b)
[0353] Compound 80b was prepared by subjecting compound 79b to general procedure B. Yield=53%. Purity: >95% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.00 (m, 2H), 2.30 (m, 3H), 2.50 (m, 1H), 2.80 (m, 1H), 5.00 (m, 1H), 7.35 (s, 2H), 8.25 (m, 1H), 8.45 (s, 1H), 8.95 (s, 1H), 10.65 (s, 1H).
[0354] (1R, 3S)-1-(9-Adenenyl)-3-carboxycyclopentane (81a)
[0355] Compound 81a was prepared by subjecting compound 79a to general procedure C. Yield=60%. Purity: >99% (HPLC method C). 1H NMR (400 MHz , DMSO): δ2.10-2.40 (m, 5H), 2.55 (m, 1H), 3.05 (m, 1H), 5.00 (m, 1H), 7.35 (s, 2H), 8.25 (s, 1H), 8.35 (s, 1H), 12.40 (s, 1H).
[0356] (1S, 3R)-1-(9-Adenenyl)-3-carboxycyclopentane (81b)
[0357] Compound 81b was prepared by subjecting compound 79b to general procedure C. Yield=58%. Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.10-2.40 (m, 5H), 2.55 (m, 1H), 3.05 (m, 1H), 5.00 (m, 1H), 7.35 (s, 2H), 8.25 (s, 1H), 8.35 (s, 1H), 12.40 (s, 1H).
[0358] (1S, 3R)-1-(9-Adenenyl)-3-methylcarboxy-4-cyclopentene (82a)
[0359] Compound 82a was prepared by subjecting compound 78a to general procedure V. Yield=98%. Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.25 (m, 1H), 2.95 (m, 1H), 3.75 (s, 3H), 3.90 (m, 1H), 5.75 (m, 1H), 6.20 (m, 1H), 6.30 (m, 1), 7.35 (s, 2H), 8.05 (s, 1H), 8.25 (s, 1H).
[0360] (1R, 3S)-1-(9-Adenenyl)-3-methylcarboxy-4-cyclopentene (82b)
[0361] Compound 82b was prepared by subjecting compound 78b to general procedure V. Yield=97%. Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.25 (m, 1H), 2.95 (m, 1H), 3.75 (s, 3H), 3.90 (m, 1H), 5.75 (m, 1H), 6.20 (m, 1H), 6.30 (m, 1H), 7.35 (s, 2H), 8.05 (s, 1H), 8.25 (s, 1H).
[0362] (1S, 3R)-1-(9-Adenenyl)-3-(N-hydroxycarbamoyl)-4-cyclopentene (83a) and (1S, 3S)-1-(9-Adenenyl)-3-(N-hydroxycarbamoyl)-4-cyclopentene (84a)
[0363] Compound 82a was subjected to general procedure B and the products were separated by preparative HPLC as described. The isolated TFA salts were converted to free bases utilizing MP-carbonate resin (Argonaut) in MeOH. Compound 83a: Yield=44%. TLC: R f =0.34 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.10 (m, 1H), 2.90 (m, 1H), 3.55 (m, 1H), 5.80 (m, 1H), 6.15 (m, 1H), 6.20 (m, 1H), 7.35 (s, 2H), 8.25 (s, 1H), 8.35 (s, 1H), 9.05 (bs, 1H), 10.80 (bs, 1H). Compound 84a: Yield=26%. TLC: R f =0.29 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.30 (m, 1H), 2.75 (m, 1H), 3.85 (m, 1H), 5.85 (m, 1H), 6.15 (m, 1H), 6.20 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1H), 8.25 (s, 1H), 9.00 (s, 1H), 10.80 (s, 1H).
[0364] (1R, 3S)-1-(9-Adenenyl)-3-(N-hydroxycarbamoyl)-4-cyclopentene (83b) and (1R, 3R)-1-(9-Adenenyl)-3-(N-hydroxycarbamoyl)-4-cyclopentene (84b)
[0365] Compound 82b was subjected to general procedure B and the products were separated by preparative HPLC as described. The isolated TFA salts were converted to free bases utilizing MP-carbonate resin (Argonaut) in MeOH. Compound 83b: Yield=44%. TLC: R f =0.32 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.10 (m, 1H), 2.90 (m, 1H), 3.55 (m, 1H), 5.80 (m, 1H), 6.15 (m, 1H), 6.20 (m, 1H), 7.35 (s, 2H), 8.25 (s, 1H), 8.35 (s, 1H), 9.05 (bs, 1H), 10.80 (bs, 1H). Compound 84b: Yield=24%. TLC: R f =0.26 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.30 (m, 1H), 2.75 (m, 1H), 3.85 (m, 1H), 5.85 (m, 1H), 6.15 (m, 1H), 6.20 (m, 1H), 7.35 (s, 2H), 8.15 (s, 1), 8.25 (s, 1H), 9.00 (bs, 1H), 10.80 (bs, 1H).
[0366] (1R, 3R)-1-(9-Adenenyl)-3-(N-hydroxycarbamoyl)cyclopentane (85a)
[0367] Compound 85a was prepared by subjecting compound 84a to general procedure G where 10% Pd/C was replaced with 20% Pd(OH) 2 /C. Yield=99%. TLC: R f =0.27 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >97% (BPLC method C). 1 H NMR (400 MHz, DMSO): δ1.90 (m, 1H), 2.15-2.40 (m, 5H), 2.95 (m, 1H), 5.05 (m, 1H), 7.30 (s, 2H), 8.25 (s, 1H), 8.30 (s, 1H), 8.90 (s, 1H), 10.60 (s, 1H).
[0368] (1S, 3S)-1-(9-Adenenyl)-3-(N-hydroxycarbamoyl)cyclopentane (85b)
[0369] Compound 85b was prepared by subjecting compound 84b to general procedure G where 10% Pd/C was replaced with 20% Pd(OH) 2 /C. Yield=95%. TLC: R f =0.27 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >97% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ1.90 (m, 1H), 2.15-2.40 (m, 5H), 2.95 (m, 1H), 5.05 (m, 1H), 7.30 (s, 2H), 8.25 (s, 1H), 8.30 (s, 1H), 8.90 (s, 1H), 10.60 (s, 1H).
[0370] (1S, 3R)-1-(9-Adenenyl)-3-carboxy-4-cyclopentene (86a) and (1S, 3S)-1-(9-Adenenyl)-3-carboxy-4-cyclopentene (87a) and (1R)-1-(9-Adenenyl)-3-carboxy-3-cyclopentene (88a)
[0371] Compound 82a was subjected to general procedure C yielding a mixture of compounds 86a, 87a and 88a. Utilizing preparative HPLC (0-10% CH 3 CN/30 minutes), compound 86a was separated from compounds 87a and 88a. Compounds 87a and 88a could not be separated from one another. All compounds were isolated as TFA salts. Compound 86a: Yield=30%. TLC: R f =0.19 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >84% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.25 (m, 1H), 2.95 (m, 1H), 3.85 (m, 1H), 5.80 (m, 1H), 6.20 (m, 1H), 6.40 (m, 1H), 8.30 (s, 1H), 8.50 (m, 3H). Compounds 87a and 88a: Yield=60%. 87a/88a=4/5. TLC: R f =0.19 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.35 (m, 1H, 87a), 2.85 (m, 1H, 87a), 3.05 (m, 2H, 88a), 3.25 (m, 2H, 88a), 4.15 (m, 1H, 87a), 5.45 (m, 1H, 88a), 5.90 (m, 1H, 87a), 6.15 (m, 1H, 87a), 6.15 (m, 1H, 87a), 6.35 (m, 1H, 87a), 6.90 (m, 1H, 88a), 8.40 (s, 1H, 87a), 8.50 (s, 1H, 87a), 8.50 (s, 1H, 88a), 8.50 (s, 1H, 88a), 8.55 (s, 1H, 88a), 8.60 (bs, 2H, 87a), 8.60 (bs, 2H, 88a).
[0372] (1R, 3S)-1-(9-Adenenyl)-3-carboxy-4-cyclopentene (86b) and (1R, 3R)-1-(9-Adenenyl)-3-carboxy-4-cyclopentene (87b) and (1S)-1-(9-Adenenyl)-3-carboxy-3-cyclopentene (88b)
[0373] Compound 82b was subjected to general procedure C yielding a mixture of compounds 86b, 87b and 88b. Utilizing preparative HPLC (0-10% CH 3 CN/30 minutes), compound 86b was separated from compounds 87b and 88b. Compounds 87b and 88b could not be separated from one another. All compounds were isolated as TFA salts. Compound 86b: Yield=41%. TLC: R f =0.20 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >93% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.25 (m, 1H), 2.95 (m, 1H), 3.85 (m, 1H), 5.80 (m, 1H), 6.20 (m, 1H), 6.40 (m, 1H), 8.30 (s, 1H), 8.50 (s, 1H), 8.85 (bs, 2H). Compounds 87b and 88b: Yield=68%. 87b/88b=1/2. TLC: R f =0.20 (CHCl 3 /MeOH/H 2 O 150/45/5). Purity: >99% (HPLC method C). 1 H NMR (400 MHz, DMSO): δ2.35 (m, 1H, 87b), 2.85 (m, 1H, 87b), 3.05 (m, 2H, 88b), 3.25 (m, 2H, 88b), 4.15 (m, 1H, 87b), 5.45 (m, 1H, 88b), 5.90 (m, 1H, 87b), 6.15 (m, 1H, 87b), 6.35 (m, 1H), 87b), 6.90 (m, 1H, 88b), 8.40 (s, 1H, 87b), 8.50 (s, 1H, 87b), 8.50 (s, 1H, 88b), 8.55 (s, 1H, 88b), 8.60 (bs, 2H, 87b), 8.60 (bs, 2H, 88b).
[0374] Biological Assays
[0375] For measurement of adenylyl cyclase activities, is is ideal to utilize a cell line which over-expresses human type V recombinant Adenylyl Cyclase (AC) as compared to ordinary cells. Preferably the AC is expressed in the cell line HEK293. Membranes isolated from these cells which have been transfected with a DNA fragment encoding AC can demonstrate a 40-50 fold stimulation by recombinant activated Gs-alpha when compared to empty vector (pcDNA3), control populations of this cell line. Stimulation with activated Gs-alpha can be used to demonstrate that 90-98% of the cAMP generation in the human AC V populations is due to expression of the recombinant adenylyl cyclase.
[0376] Type V AC activity for compounds according to the invention is evaluated in an AC transfected cell line (transfected as described above, for example) with added control inhibitors (positive control) or without added control inhibitors (negative control) or with an added compound according to the invention. The assay can be adapted to follow an established protocol for AC expression, an example, of which, is summarized generally herein for clarity. Membranes (140 ng/ml) are used in the presence of a control incubation solution 60 mM HEPES, pH 8.0, 0.6 mM EDTA, 0.01% (w/v) Bovine serum albumin, 25 nM activated recombinant Gs-alpha, 1 mM ATP, 2 mM isobutyl methyl xanthine and 2 mM MgCl 2 . To this control solution may be added a positive control compound or a compound according to the present invention and the mixture is incubated for 30 minutes at 30 degrees Centigrade. Upon termination of incubation, the mixture is evaluated for the enzymatic product, cAMP using a commercially available New England Nuclear flash plate system. The degree of inhibition for the positive control or a compound according to the present invention is determined by comparing the results from the positive control or compound according to the invention to results from the negative control which utilized only the incubation solution without any positive control or compound according to the present invention.
[0377] The compounds of formula (I) and pharmaceutically acceptable salts thereof can be administered as such, but it is usually preferred to administer them in the form of pharmaceutical compositions, which are used for animals and human beings.
[0378] Compositions or formulations of the compounds of the invention are prepared for storage or administration by mixing the compound having a desired degree of purity with physiologically acceptable carriers, excipients, stabilizers etc., and may be provided in sustained release or timed release formulations. Acceptable carriers or diluents for therapeutic use are well known in the pharmaceutical field, and are described, for example, in Remington's Pharmaceutical Sciences, Mack Publishing Co., (A. R. Gennaro edit. 1985). Such materials are nontoxic to the recipients at the dosages and concentrations employed, and include buffers such as phosphate, citrate, acetate and other organic acid salts, antioxidants such as ascorbic acid, low molecular weight (less than about ten residues) peptides such as polyarginine, proteins, such as serum albumin, gelatin, or immunoglobulins, hydrophilic polymers such as polyvinylpyrrolidinone, amino acids such as glycine, glutamic acid, aspartic acid, or arginine, monosaccharides, disaccharides, and other carbohydrates including cellulose or its derivatives, glucose, mannose or dextrins, chelating agents such as EDTA, sugar alcohols such as mannitol or sorbitol, counterions such as sodium and/or nonionic surfactants such as TWEEN®, PLURONICS® or polyethyleneglycol.
[0379] The term “effective amount” is an amount necessary for administering the compound in accordance with the present invention to provide the necessary effect such as inhibiting the phosphorylation of kinases or treating disease states in a mammal. In accordance with the present invention, a suitable single dose size is a dose that is capable of preventing or treating an animal with a disease when administered one or more times over a suitable time period. Doses can vary depending upon the disease being treated. For example, in the treatment of hypersensitivity, a suitable single dose can be dependent upon the nature of the immunogen causing the hypersensitivity.
[0380] An effective administration protocol (i.e., administering a therapeutic composition in an effective manner) comprises suitable dose parameters and modes of administration that result in prevention or treatment of a disease. Effective dose parameters and modes of administration can be determined using methods standard in the art for a particular disease. Such methods include, for example, determination of survival rates, side effects (i.e., toxicity) and progression or regression of disease. For example, the effectiveness of dose parameters and modes of administration of a therapeutic composition of the present invention can be determined by assessing response rates. Such response rates refer to the percentage of treated patients in a population of patients that respond with either partial or complete remission.
[0381] It is preferred to employ the administration route which is the most effective for the treatment. For example, administration is made orally or non-orally by intrarectal, intraoral, subcutaneous, intramuscular or intravenous administration.
[0382] Examples of the forms for administration are capsules, tablets, granules, powders, syrups, emulsions, suppositories and injections.
[0383] Liquid compositions such as emulsions and syrups which are appropriate for oral administration can be preparedusingwater, sugars such as sucrose, sorbitol and fructose, glycols such as polyethylene glycol and propylene glycol, oils such as sesame oil, olive oil and soybean oil, preservatives such as benzoates, flavors such as strawberry flavor and peppermint, etc.
[0384] Capsules, tablets, powders and granules can be prepared using excipients such as lactose, glucose, sucrose and mannitol, disintegrating agents such as starch and sodium alginate, lubricants such as magnesium stearate and talc, binders such as polyvinyl alcohol, hydroxypropyl cellulose and gelatin, surfactants such as fatty acid esters, plasticizers such as glycerin, etc.
[0385] Compositions suitable for non-oral administration preferably comprise a sterilized aqueous preparation containing an active compound which is isotonic to the recipient's blood. For example, injections are prepared using a carrier which comprises a salt solution, a glucose solution, or a mixture of a salt solution and a glucose solution.
[0386] Compositions for topical application are prepared by dissolving or suspending an active compound in one or more kinds of solvents such as mineral oil, petroleum and polyhydric alcohol, or other bases used for topical drugs.
[0387] Compositions for intestinal administration are prepared using ordinary carriers such as cacao fat, hydrogenated fat and hydrogenated fat carboxylic acid, and are provided as suppositories.
[0388] The compositions for non-oral administration may additionally be formulated to contain one or more kinds of additives selected from glycols, oils, flavors, preservatives (including antioxidants), excipients, disintegrating agents, lubricants, binders, surfactants and plasticizers which are used for the preparation of compositions for oral administration.
[0389] The effective dose and the administration schedule for each of the compounds of formula (I) or a pharmaceutically acceptable salt thereof will vary depending on the administration route, the patient's age and body weight, and the type or degree of the diseases to be treated. However, it is generally appropriate to administer a compound of formula (I) or a pharmaceutically acceptable salt thereof in a dose of 0.01-1000 mg/adult/day, preferably 5-500 mg/adult/day, in one to several parts.
[0390] All the compounds of the present invention can be immediately applied to the treatment of kinase-dependent diseases of mammals as kinase inhibitors, specifically, those relating to tyrosine kinase. Specifically preferred are the compounds which have IC50 within the range of 10 nM-10 μM. Even more preferred are compounds which have IC50 within the range of 10 μM to -1 μM. Most preferred are compounds which have an IC50 value which is smaller than 1 μM.
[0391] Specific compounds of the present invention which have an activity to specifically inhibit one of the three types of protein kinase (for example, kinase which phosphorylates tyrosine, kinase which phosphorylates tyrosine and threonine, and kinase which phosphorylates threonine) can be selected. Tyrosine kinase-dependent diseases include hyperproliferative malfunction which is caused or maintained by abnormal tyrosine kinase activity. Examples thereof include psoriasis, pulmonary fibrosis, glomerulonephritis, cancer, atherosclerosis and anti-angiopoiesis (for example, tumor growth and diabetic retinopathy). Current knowledge of the relationship between other classes of kinase and specific diseases is insufficient. However, compounds having specific PTK-inhibiting activity have a useful treatment effect. Other classes of kinase have also been recognized in the same manner. Quercetin, genistein and staurosporin, which are all PTK-inhibitors, inhibit many kinds of protein kinase in addition to tyrosine kinase. However, as a result of their lack of the specificity, their cytotoxicity is high. Therefore, a PTK-inhibitor (or an inhibitor of other classes of kinase) which is apt to bring about undesirable side effects because of the lack of selectivity can be identified by the use of an ordinary test to measure cytotoxicity.
[0392] The present invention provides nitrogen-containing heterocyclic compounds and pharmaceutically acceptable salts thereof which inhibit phosphorylation of PDGF receptor to hinder abnormal cell growth and cell wandering and thus are useful for the prevention or treaLment of cell-proliferative diseases such as arteriosclerosis, vascular reobstruction, cancer and glomerulosclerosis.
[0393] Dosage formulations of the compounds of the invention to be used for therapeutic administration must be sterile. Sterility is readily accomplished by filtration through sterile membranes such as 0.2 micron membranes, or by other conventional methods. Formulations typically will be stored in lyophilized form or as an aqueous solution. The pH of the preparations of the invention typically will be about 3-11, more preferably about 5-9 and most preferably about 7-8. It will be understood that use of certain of the foregoing excipients, carriers, or stabilizers will result in the formation of cyclic polypeptide salts. While the preferred route of administration is by injection, other methods of administration are also anticipated such as orally, intravenously (bolus and/or infusion), subcutaneously, intramuscularly, colonically, rectally, nasally, transdermally or intraperitoneally, employing a variety of dosage forms such as suppositories, implanted pellets or small cylinders, aerosols, oral dosage formulations and topical formulations such as ointments, drops and dermal patches. The compounds of the invention are desirably incorporated into shaped articles such as implants which may employ inert materials such as biodegradable polymers or synthetic silicones, for example, Silastic, silicone rubber or other polymers commercially available.
[0394] The compounds of the invention may also be administered in the form of liposome delivery systems, such as small unilamellar vesicles, large unilamellar vesicles and multilamellar vesicles. Liposomes can be formed from a variety of lipids, such as cholesterol, stearylamine or phosphatidylcholines.
[0395] The compounds of the invention may also be delivered by the use of antibodies, antibody fragments, growth factors, hormones, or other targeting moieties, to which the compound molecules are coupled. The compounds of the invention may also be coupled with suitable polymers as targetable drug carriers. Such polymers can include polyvinylpyrrolidinone, pyran copolymer, polyhydroxy-propyl-methacrylamide-phenol, polyhydroxyethyl-aspartamide-phenol, or polyethyleneoxide-polylysine substituted with palmitoyl residues. Furthermore, compounds of the invention may be coupled to a class of biodegradable polymers useful in achieving controlled release of a drug, for example polylactic acid, polyglycolic acid, copolymers of polylactic and polyglycolic acid, polyepsilon caprolactone, polyhydroxy butyric acid, polyorthoesters, polyacetals, polydihydropyrans, polycyanoacrylates and cross linked or amphipathic block copolymers of hydrogels. Polymers and semipermeable polymer matrices may be formed into shaped articles, such as valves, stents, tubing, prostheses and the like.
[0396] Therapeutic compound liquid formulations generally are placed into a container having a sterile access port, for example, an intravenous solution bag or vial having a stopper pierceable by hypodermic injection needle.
[0397] Therapeutically effective dosages may be determined by either in vitro or in vivo methods. For each particular compound of the present invention, individual determinations may be made to determine the optimal dosage required. The range of therapeutically effective dosages will be influenced by the route of administration, the therapeutic objectives and the condition of the patient. For injection by hypodermic needle, it may be assumed the dosage is delivered into the body's fluids. For other routes of administration, the absorption efficiency must be individually determined for each compound by methods well known in pharmacology. Accordingly, it may be necessary for the therapist to titer the dosage and modify the route of administration as required to obtain the optimal therapeutic effect. The determination of effective dosage levels, that is, the dosage levels necessary to achieve the desired result, will be readily determined by one skilled in the art. Typically, applications of compound are commenced at lower dosage levels, with dosage levels being increased until the desired effect is achieved.
[0398] The compounds and compositions of the invention can be administered orally or parenterally in an effective amount within the dosage range of about 0.001 to about 1000 mg/kg, preferably about 0.01 to about 100 mg/kg and more preferably about 0.1 to about 20 mg/kg. Advantageously, the compounds and composition of the invention may be administered several times daily. Other dosage regimens may also be useful (e.g. single daily dose and/or continuous infusion).
[0399] Typically, about 0.5 to about 500 mg of a compound or mixture of compounds of the invention, as the free acid or base form or as a pharmaceutically acceptable salt, is compounded with a physiologically acceptable vehicle, carrier, excipient, binder, preservative, stabilizer, dye, flavor etc., as called for by accepted pharmaceutical practice. The amount of active ingredient in these compositions is such that a suitable dosage in the range indicated is obtained.
[0400] Typical adjuvants which may be incorporated into tablets, capsules and the like are binders such as acacia, corn starch or gelatin, and excipients such as microcrystalline cellulose, disintegrating agents like corn starch or alginic acid, lubricants such as magnesium stearate, sweetening agents such as sucrose or lactose, or flavoring agents. When a dosage form is a capsule, in addition to the above materials it may also contain liquid carriers such as water, saline, or a fatty oil. Other materials of various types may be used as coatings or as modifiers of the physical form of the dosage unit. Sterile compositions for injection can be formulated according to conventional pharmaceutical practice. For example, dissolution or suspension of the active compound in a vehicle such as an oil or a synthetic fatty vehicle like ethyl oleate, or into a liposome may be desired. Buffers, preservatives, antioxidants and the like can be incorporated according to accepted pharmaceutical practice.
[0401] Without further description, it is believed that one of ordinary skill in the art can, using the preceding description and the illustrative examples, make and utilize the compounds of the present invention and practice the claimed methods. It should be understood that the foregoing discussion and examples merely present a detailed description of certain preferred embodiments. It will be apparent to those of ordinary skill in the art that various modifications and equivalents can be made without departing from the spirit and scope of the invention. All the patents, journal articles and other documents discussed or cited above are herein incorporated by reference. | The present invention relates to derivatives and analogues of adenine, which inhibit adenylyl cyclase activity. The present invention also relates to a method of preventing and inhibiting a patient's fibroproliferative vasculopathy following vascular injury or a vascular surgical operation which includes administering to the patient, an effective amount of a compound according to the invention subsequent to a vascular injury, or subsequent to a vascular surgical operation, for one to two weeks after the injury or surgical operation, effective to treat or prevent a patient's fibroproliferative vasculopathy such as chronic allograft rejection or vascular restenosis following vascular trauma. The present invention also relates to a method for measuring the inhibition of adenylyl cyclase activity and a method for treating congestive heart failure. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable
REFERENCE TO SEQUENCE LISTINGS
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] The present invention relates to electronic controls that must determine if a path of an ac circuit is intact or open. Typically this means determining whether a switching component is open or closed, or a whether a functional component is present.
[0005] Typically the state of a component that switches an ac load is determined using optoisolators or other active components to interface ac voltages to electronic control level voltages. Alternatively a low voltage switch acting in unison with the ac switch is read by the control to indirectly determine the state of the ac switch. One prior passive component approach with an isolated supply requires a conditioning circuit between ac nodes and works only when the neutral line is the one switched. Other prior passive component approaches only work on supplies that are not isolated from ac. They require a fixed voltage between the control voltages and the ac source.
[0006] The approach of using optoisolators or active components requires the use of multiple components for each input to the control. Typically these components include at a minimum an optoisolator, a current limiting resistor on the input and a pull-up resistor on the output. The cost of these components and their assembly add significantly to the cost of electronic controls. The use of active components and the number of components reduce the reliability of this approach.
[0007] Using a separate control voltage switch incurs the expense of the switch and the extra connectors and wires to interface it to the control. There is additional expense of mounting hardware and labor. The reliability of mechanical systems is typically far less than a solid state approach.
[0008] A technique to interface an electronic control to ac using a resistor, is shown in AN521 of Microchip's Embedded Control Handbook. In this approach the ground of the control is in common with the ac ground establishing ground as a reference. A resistive connection to hot produces ac source frequency pulses. There is no mention of a means of detecting the state of a node whose connections to hot and/or neutral are not already known. This approach relies on the fixed reference of the common ground that is not present with a floating supply. Proper connections to hot and neutral are assumed. If L1 and neutral were inadvertently reversed in installation the technique will not work.
[0009] U.S. Pat. No. 5,202,582 shows a method to determine the state of an ac switch connecting the load to neutral for a floating control using passive components. This approach requires a conditioning circuit with connections to L1, the load side of the switch and a control input. It is designed to determine solely the state of a ground side switch of an ac circuit. The conditioning circuit shapes signal. The shape determines the state of the switch.
[0010] This method assumes the correct connections to ac are made during installation, something that is not under the control of the manufacturer. Further this approach requires that neutral be switched leaving the transducers connected to hot unless a L1 side switch is also opened when the door is opened. Finally no method is shown to sense the state of a plurality of ac switches in the same circuit or a plurality of circuits.
[0011] U.S. Pat. No. 5,184,026 shows a method that can be used for a plurality of switches. However the method deals with controls whose supply voltages are not isolated from the ac source. Supplies that are not isolated bring the possibility of shock or worse should the operator come in contact with any control voltage. As described the monitoring device requires a reference voltage that is a dc drop from the instantaneously higher of the source lines. To produce such a reference requires multiple components and connections between the source and the control. The monitoring device must include a reactive component to block the dc voltage between the ac node and the control for this approach to work. The reactive components used to block dc alter the phase of signal received by the control.
BRIEF SUMMARY OF INVENTION
[0012] The present invention connects ac nodes and digital nodes of a control with a floating power supply to determine the state of ac path(s) in the circuit containing the ac nodes. The digital nodes of the present invention are either digital inputs or the supply voltages for the digital circuitry. The connections are made through passive components. The ac potential between the source and the control drives the digital nodes. The subsequent signals on digital nodes are compared to determine the state of ac path(s).
[0013] The present invention can determine the state of a plurality of ac paths. The paths may be anywhere in the ac circuit. The state of the path indicates whether it is intact or open. The state of a path can be used to determine the state of a switching means. It can also determine if a functional load component is present. The present invention can also determine if an ac node is floating indicating that all ac paths to the node are open.
[0014] The method may be applied to devices where the polarity of the connection to the ac source is unknown. The method may be used to detect zero crossings. The high impedance connections allow inputs to perform other I/O functions when not reading the state of an ac node. The aggregate source-control impedance may be made sufficient to limit the current to a safe level, preferrably below the threshold of sensation, should the operator contact any control node.
[0015] The simplest connection, one made by a resistor, is the preferred connection. It ensures that if the digital input has a phase it is the same phase as the driving ac signal. While reactive (energy storing) components may be used in the connections to further distinguish signals they are not required, alter the phase of the signal and add to the cost.
[0016] The reliability of the present invention is much greater than the prior approaches given the reduction in the number of interface components. Additionally resistors, the preferred passive component in the connections, are most reliable electrical components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is the schematic of the control used to operate the dishwasher in the first embodiment.
[0018] FIGS. 2 A-E are graphs of voltage versus time occurring on the inputs of the controls in the first and second embodiments.
[0019] [0019]FIG. 3 is the schematic of the control used to operate the dishwasher in the second embodiment.
[0020] [0020]FIG. 4 is the schematic of the optional control used to operate the dishwasher in the second embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Although both the following embodiments are 120 v ac dishwashers it is to be understood that the inventor contemplates the invention being applied to other devices with the same or different ac transducers and switching means operating off various ac voltages.
[0022] First Embodiment
[0023] This embodiment is a dishwasher control. The schematic for the first embodiment is shown in FIG. 1. The ac transducers are a motor 70 , a heating element 80 and a solenoid 60 operating a water inlet valve. Operation of the motor 70 and the heating element 80 can be stopped by either the door switch, S 1 or the ac switching 50 operated by the control electronics 40 . Operation of the inlet valve solenoid 60 can be interrupted by the ac switching 50 , the door switch S 1 or the float switch S 2 .
[0024] When correctly installed, line L 1 of the ac source is connected to S 1 and neutral is connected directly to solenoid 60 , motor 70 and heating element 80 . The input of transformer 20 is also connected to the ac source 10 . The power supply 30 is connected to the output of transformer 20 . The power supply 30 produces dc voltages, +5 v and Gnd, for the control electronics 40 and the input side of the ac switching 50 . The output of the power supply 30 is isolated from the ac source by 20 . The control electronics 40 selectively activate the ac transducers using the ac switching module 50 . While this embodiment uses a linear power supply the approach is the same for any isolated power supply.
[0025] During a wash cycle the control activates and times the operation of each transducer. The control must measure only the time a transducer is active, hence it must be able to determine the state of the door switch S 1 . When S 1 is opened during transducer operation the control suspends its operation until S 1 is once again closed. The water fill is timed, S 2 does not open during normal operation. S 2 remains closed unless a fault causes the dishwasher to overfill. The control does not monitor the state of S 2 .
[0026] In this embodiment of the present invention the control compares the signals received through resistors R 1 and R 2 to determine the state the ac path containing the door switch, S 1 . R 1 is connected between the unswitched ac source side of S 1 and digital input 1 of the control electronics 40 . R 2 is connected between the opposing side of S 1 and digital input 2 of 40 . Both inputs have high impedance. Input 1 also serves as a designated counter used to time operation by counting the pulses on its input. The control 40 uses the 60 hz signal produced on input 1 to accurately time the operation of the dishwasher. This means the only component unique to determining the state of S 1 is R 2 .
[0027] When S 1 is opened during operation of any transducer, S 1 is the only break in the ac circuit. The 60 hz signals on inputs 1 and 2 are 180° out of phase as shown in FIGS. 2A and 2B. When input 1 is high, input 2 is low. When 2 is high 1 is low. This is true regardless of the polarity of the connection to the ac source 10 . The signals are the portions of the 60 hz sinusoidal wave of the ac source 10 truncated by internal protection diodes of inputs 1 and 2 . The signals are limited to +5.6 v and −0.6 v as long as R 1 and R 2 have sufficient resistance to limit the current through the protection diodes. Further R 1 and R 2 limit the current from the ac source 10 to less than the threshold of sensation providing shock protection in the event the operator contacts a control level node.
[0028] When the door switch S 1 is closed, inputs 1 and 2 received the same signal (FIG. 2A) since R 1 and R 2 are connected to the same ac potential. In this embodiment the intrinsic impedance between the supply voltages and the source 10 complete the input-source loop. The high input impedance of 1 and 2 ensure that the fraction of the ac source voltage dropped across these inputs is sufficient to alter the state of each input. Thus anytime 1 and 2 are both high or both low S 1 is closed.
[0029] In this embodiment there is no need to determine the state of S 1 when no transducer is selected since the operation of the control is unaffected. Should the operation call for the activation of a transducer when the door has previously been opened, the control will use the ac switching means 50 to select the transducer. After a transducer is selected the control will detect the open door just as it would when the door is opened when a transducer is active. The control will then suspend operation until S 1 is closed.
[0030] If it were necessary to determine the state of S 1 when no transducer is selected by 50 the control must be able to determine that the ac node of R 2 is floating, isolated from both L 1 and neutral. When the switched side of S 1 is isolated, the signal at 2 has approximately a 90° phase shift to the signal on 1 as shown in FIG. 2C. The signal is caused by the intrinsic impedance between the source and the switched side node of S 1 . The signal on 2 will not be low the entire time 1 is high as it is when S 1 is the only break in the circuit. Scanning is done over the period 1 is high. If 2 is goes low anytime during this period S 1 is open.
[0031] While the ability to distinguish when the R 2 ac node is floating adds no expense in term of hardware the trade off is in more involved scanning. When the only signals the control needs to detect are those in FIGS. 2A and 2B detection can be made at any instant other than when the signals are changing state. The second embodiment demonstrates a means of connecting to ac nodes so that the scan to detect floating nodes is simplified.
[0032] Second Embodiment
[0033] In this embodiment resistors R 3 -R 9 are added to the control as shown in FIG. 3. Components introduced in the first embodiment perform the same function unless noted in the text. The mechanics of the washer are the same as the first embodiment except fill stops when the float switch S 2 opens rather than being timed. This control monitors the states of S 1 and S 2 . The control also monitors the functionality of inlet solenoid 60 and heating element 80 by connecting resistors R 3 and R 4 between them and inputs 3 and 4 respectively.
[0034] In this embodiment resistors R 5 -R 7 reduce the impedance between inputs 2 - 4 and control ground. Instead of the signal in FIG. 2C, a floating node in this embodiment produces the signal in FIG. 2D. The small magnitude of this signal ensures that it is read as a fixed low. Unlike the signals in FIGS. 2 A-C this signal has no detected phase. In FIG. 2, the signal in 2 D is easier to distinguish than the signal in 2 C from the signals in 2 A and 2 B. In this embodiment the simplified scanning required to distinguish the 2 D signal allows the use of a lower cost CPU (not shown) with less memory thus recovering the cost of including R 5 -R 7 .
[0035] R 8 and R 9 bias the control relative to the source ensuring that when a sensed ac node is at either line potential the signal in FIGS. 2A or 2 B is produced. Choosing R 9 <R 8 <<R 1 -R 4 performs two functions: 1) it biases the control nearer what is nominally neutral allowing a state change on input 1 to serve as a zero crossing detector. 2) when the ac nodes for inputs 1 - 4 are at the same line potential it prevents the control from becoming so closely biased to that ac line that the signal on inputs 2 - 4 would be reduced to the signal in FIG. 2D. Thus in this embodiment only floating ac nodes produce a fixed low signal.
[0036] In this embodiment the state of S 1 is again determined by comparing the signal on input 1 with the signal on input 2 . When S 1 is closed both inputs have the signal in FIG. 2A. When S 1 is open, the signal on 1 remains the one in FIG. 2A. FIG. 2B shows the signal on 2 when S 1 is open with a transducer selected. FIG. 2D shows the signal on 2 when S 1 is open with no transducer selected. R 5 lowers the input impedance sufficiently to maintain 2 in the low digital state when its ac node is floating. The signals in FIGS. 2B and 2D are both low when 1 is high. Hence S 1 is open if 2 is low when 1 is high. S 1 is closed if 2 is high when 1 is high. When S 1 is open the control suspends operation.
[0037] In this dishwasher S 2 determines the fill level. S 2 is closed until the fill level is reached when it opens breaking the circuit of the solenoid 60 . During fill the signals on inputs 2 and 3 are compared. They are in phase until S 2 opens. This is true regardless of the state of S 1 . If S 1 remains closed when S 2 is open the signals on inputs 2 and 3 are those of FIGS. 2A and 2B. If both S 1 and S 2 open the signals are those of FIGS. 2D and 2B. Thus if input 2 is low when input 3 is high S 2 is open. When S 2 opens the control proceeds to the next step in the wash cycle after the fill.
[0038] To determine the functionality of the solenoid 60 and the heating element 80 the control scans their paths when their transducers are inactive. An intact path indicates a functional transducer. If a path is open, its transducer is non-functional either because it or a part of the circuit has failed. The signal on input 1 , FIG. 2A, is used as a reference. A functional component will produce the signal in FIG. 2B regardless of the polarity of the connections to ac 10 . If the transducer is non-functional the ac node tested will be floating producing a fixed low signal (FIG. 2D) on its digital input. Inputs 3 and 4 are scanned when 1 goes low. If 3 is high the solenoid 60 is functional. If 4 is high the heating element 80 is functional. If 3 is low 60 is non-functional. If 4 is low 80 is non-functional.
[0039] All connections of the present invention, not just R 8 and R 9 together with the intrinsic impedance between all nodes and the source bias the control relative to the source. When an ac path state produces the signal in FIG. 2D and/or FIG. 2E a supply node can be used as a reference signal. In the circuit in FIG. 3 ground can be used as a reference signal to determine the functionality of the heating element 80 and the inlet valve 60 respectively. If either input remains at zero for one ac source period, 16.7 msec, its respective transducer has failed.
[0040] Neither method can determine the functionality of the heating element 80 at any instant, though when the signal on input 1 is used as a reference functionality can be determined anytime 1 is low. The addition of diode D 1 and capacitor C 1 as shown in FIG. 4 removes the phase of the signal detected by the input 4 . When 80 is functional the signal on input 4 as shown in FIG. 2E in. If 80 is non-functional the signal remains that in FIG. 2D. These signals can be distinguished at any instant.
[0041] In this embodiment, zero crossings are detected when input 1 changes state. The accuracy of this method depends on where the control ground is biased. The closer the control is biased to the source line not connected to R 1 the greater the accuracy of the zero crossing. Without R 8 and R 9 the bias of the ground is dramatically changed by the state of S 1 , S 2 and the ac switches 50 . This is particularly true when all the transducers are active causing all tested ac nodes to be at the same potential as the unswitched side of S 1 . Selecting R 9 <R 8 <<R 1 -R 4 minimizes the affect the state of the ac nodes sensed by R 1 -R 4 has on the bias of control ground.
[0042] In both of the embodiments the aggregate source-control impedance is sufficient to limit the current to below the threshold of sensation should the operator contact any digital node. To guard against a failure of the connecting components resulting in control failure or operator shock multiple components may be used instead of single units. | An electronic control, with a floating ac power supply, that compares the digital signals produced by connections between ac circuit nodes and digital nodes to determine whether path(s) in ac circuits containing the ac nodes are intact or open. The connections are made through passive components which limit the current between nodes to levels the digital devices can safely handle. An open path indicates to the control that a switching device is open, a connection has failed, or a that a load component has failed or is missing. An intact path indicates a closed switch or a present and presumably functional load component. Proper connections enable the control to detect the state of multiple paths while still being able to detect zero crossings. The method can determine the state of ac paths even if hot and neutral connections are inadvertently reversed. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
The subject matter of the present application is related to U.S. patent application Ser. No. 08/621,166 filed Mar. 22, 1996, now abandoned, titled "VALVE FOR GAS FLOW CONTROL", assigned to the assignee hereof and herein incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates generally to an improved control means for use in systems which separate gas mixtures by pressure swing molecular sieve absorption techniques, and more specifically to the improved control means as applied to oxygen generating systems for oxygen enrichment and control.
The need for oxygen enrichment and/or oxygen composition control has been well documented in the prior art in diverse areas such as providing proper aircrew breathing mixtures in varying altitudes and providing specially constituted breathing mixtures for individuals undergoing medical treatment. The systems used to supply such special requirements commonly utilize an apparatus which employs absorptive materials designed to absorb and retain particular gas types, such as nitrogen. The most common system process is the pressure swing absorption technique.
A typical prior art pressure swing absorption system apparatus 110 is shown in FIG. 1. Inlet Air Supply 111 is applied to Pressure Regulator 112. Pressure Regulator Output 113, which is of limited pressure variation, is applied to First Input Valve 115 and Second Input Valve 120 as shown. First Absorber Bed Input 116 is supplied through First Input Valve 115. When First Input Valve 115 is open, First Vent Valve 125 is closed. With First Input Valve 115 open, air is routed through First Absorber Bed 140 where absorption of undesired gaseous components occurs because of the characteristics of the absorbing materials used in First Absorber Bed 140. After this processing, the output of First Absorber Bed 140 is routed through First Check Valve 150, which when open connects Outlet Gas Mixture 160 to the output of First Absorber Bed 140. Alternatively, when First Input Valve 115 is closed, First Vent Valve 125 is open which connects the air content of First Absorber Bed 140 to Vent 135 so that undesired trapped gaseous components are discharged from First Absorber Bed 140 to Vent 135. This desorption process is further enhanced by a controlled purge flow through Fixed Cross Flow Orifice 151. During this process First Check Valve 150 is closed. After venting of First Absorber Bed 140, the states of First Input Valve 115, First Vent Valve 125 and First Check Valve 150 are reversed and the absorption process will again occur. The cycle of absorb/vent repeats continuously during system operation.
The second half of the system, composed of Second Input Valve 120, Second Vent Valve 130, Second Absorber Bed 145 and Second Check Valve 155 operates in like manner but concurrently with the first half of the system. Second Absorber Bed Input 121 is supplied through Second Input Valve 120. When First Absorber Bed 140 is providing enriched gas mixture to Outlet Gas Mixture 160, Second Absorber Bed 145 is connected to Vent 135; and when First Absorber Bed 140 is connected to Vent 135 Second Absorber Bed 145 is providing enriched gas mixture to Outlet Gas Mixture 160. First Check Valve 150 and Second Check Valve 155 ensure that only the enriched gas mixture is routed to Outlet Gas Mixture 160 and that the venting process does not affect Outlet Gas Mixture 160.
The typical prior art pressure swing absorption system described above has been utilized as the basis for various improvement patents. U.S. Pat. Nos. 3,948,286 and 4,877,429 present improved valve devices for application in this system. U.S. Pat. No. 4,802,899 presents a way of physically arranging apparatus components to achieve system service and maintenance advantages. U.S. Pat. No. 4,567,909 describes a method of using gas flow control across the absorptive beds as a means of controlling the oxygen concentration of the final product gas. Prior art systems do not address two inherent problems encountered in applying on-board oxygen concentration systems to aircraft, which are operated from air sources of limited capacity and limited pressure, and of the dependence of overall system efficiency on the amount of conditioned air consumed during OBOGS operation which represents a power inefficiency that results in reduced aircraft performance.
The first problem not addressed in the prior art, that of operation from air sources of limited capacity and pressure, manifests itself in aircraft applications by the requirement that an effective OBOGS provide proper operation from 8 to 250 pounds per square inch gauge (PSIG) air inlet pressure, whereas prior art systems exhibit significant performance degradation with air inlet pressures below approximately 20 PSIG. PSIG, as is well known in the art, is the pounds per square inch above atmospheric pressure which is approximately 14.7 at sea level. The second problem not addressed in the prior art is the strong need for efficiency in all aircraft systems, and in particular the need for efficient OBOGS operation at critical points in the aircraft performance envelope. For example, any OBOGS inefficiency represents a loss of available engine power which in turn may manifest itself as inefficient fuel utilization or some other deficiency, such as adverse effects on the cooling or heat exchanger design.
There is thus an unmet need in the art to be able to utilize an OBOGS in airborne applications which is efficient and which will operate from limited air supplies and pressures. Therefore, it would be advantageous in the art to be able to describe a control means for molecular sieve on-board oxygen generators which will provide efficient OBOGS operation from limited air inlet supply and pressure.
SUMMARY OF THE INVENTION
It is an objective of the present invention to describe a control means for molecular sieve oxygen generating systems.
It is further an object of the present invention to describe a control means for molecular sieve oxygen generating systems which provides efficient system operation in airborne environments.
It is further an object of the present invention to describe a control means for molecular sieve oxygen generating systems which provides proper system operation from air inlet sources of limited supply and limited pressure, as is common in airborne applications.
The present invention measures both temperature and pressure of the inlet air of an oxygen generating system. An electronic control unit applies pressure limits to a pressure measurement signal and combines it with a temperature measurement signal to produce a composite analog signal responsive to both temperature and pressure inlet air conditions. This analog signal is linearly converted to a frequency signal, whereupon the frequency signal is divided by a constant in order to produce a drive signal for control of the adsorb/vent bed cycle valves. Composition control is achieved by venting product mixture as required. Inlet air pressures down to 5 PSIG produce correct system operation, and the quantity of conditioned air required is automatically limited so that system efficiency is higher than prior art systems.
Therefore, according to the present invention, a control means for molecular sieve on-board oxygen generators is presented which provides an improvement in system efficiency and which provides for proper system operation with air inlet supplies of limited capacity and limited pressure.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, and further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawing(s), wherein:
FIG. 1 is a Block Diagram of a Molecular Sieve Oxygen Generating System, according to the prior art;
FIG. 2 is a Block Diagram of a Molecular Sieve Oxygen Generating System, according to a preferred embodiment of the present invention;
FIG. 3 is a graph depicting Limits to Oxygen Concentration as a Function of Cabin Altitude;
FIGS. 4 and 4A are an Electrical Schematic of the First Portion of a Molecular Sieve Oxygen Generating System Electronic Control Unit, according to the preferred embodiment of the present invention;
FIG. 5 is an Electrical Schematic of the Second Portion of a Molecular Sieve Oxygen Generating System Electronic Control Unit, according to the preferred embodiment of the present invention;
FIG. 6 is a Mechanical Drawing of a Solenoid Operated Vent Valve utilized in the Molecular Sieve Oxygen Generating System, according to the preferred embodiment of the present invention;
FIG. 7 is a Mechanical Drawing of a Solenoid Operated Pneumatic Linear Valve utilized in the Molecular Sieve Oxygen Generating System, according to the preferred embodiment of the present invention; and
FIG. 8 is a Graph depicting Oxygen Partial Pressure versus Aircraft and Crew Altitude of an Experimental Molecular Sieve Oxygen Generating System, according to the preferred embodiment of the present invention.
DESCRIPTION OF THE INVENTION
The present invention addresses two prior art problems encountered in applying on-board oxygen concentrators to aircraft, namely aircraft with limited air inlet supply capacity and pressure at some points in the performance envelope and aircraft with large performance sensitivity to subsystem inefficiencies. For example, during engine idle conditions low bleed air supply pressure is frequently encountered and this will cause difficulty with current OBOGS, i.e. on-board oxygen generating systems. As a second example, the power inefficiency of current oxygen generating systems represents an energy drain and therefore a performance penalty for high-performance aircraft.
The present invention describes a control means for molecular sieve on-board oxygen generating systems which provides increased system efficiency and allows operation from air inlet sources of limited capacity and pressure. Whereas prior art systems have performance limitations with air inlet pressures below about 20 PSIG, the present invention provides OBOGS system operation down to 5 PSIG. The present invention also automatically limits air usage for inlet air pressures above 18 PSIG, and provides variable absorbing bed cycle rates as a function of air inlet temperature and pressure.
The present invention is also intended to provide a suitable means for controlling the concentration of product oxygen within a specified requirement band or range. This is required for aircrew breathing mixtures. The present invention is further intended to accomplish all of the above over a wide range of air supply temperatures as encountered in aircraft usage.
Referring to FIG. 2, an On-board Oxygen Generator 210 is composed of two major subassemblies, Electronic Control 245 and Molecular Sieve Oxygen Concentrator 265. Air at a nominal pressure range of approximately 5 to 250 PSIG is applied to Inlet Supply Air 215. Inlet Supply Distribution 220 routes Inlet Supply Air 215 to Inlet Supply Temperature Sensor 225, Inlet Supply Pressure Sensor 230 and Pressure Reducer 296. Pressure Reducer 296 supplies limited pressure air input to Molecular Sieve Oxygen Concentrator 265. Molecular Sieve Oxygen Concentrator 265 is a standard two bed concentrator. Inlet Supply Temperature Sensor 225 monitors the temperature of Inlet Supply Air 215, and supplies Temperature Sensor Electrical Signal 235 as an input signal to Electronic Control 245. Temperature Sensor Electrical Signal 235 is a digital signal with either proportional or fixed set point references. Inlet Supply Air 215 is also routed to Inlet Supply Pressure Sensor 230. Inlet Supply Pressure Sensor 230 generates Pressure Sensor Electrical Signal 240 which is also an input signal to Electronic Control 245. Pressure Sensor Electrical Signal 240 is proportional to gage pressure over a limited range, nominally 5 to 20 PSIG approximately, but is capable of withstanding high pressure extremes. Pressure Reducer 296 is set to control the maximum bed pressure of Molecular Sieve Oxygen Concentrator 265 to the lowest level consistent with minimum acceptable air usage at the maximum bed cycling rate. Temperature Sensor Electrical Signal 235 and Pressure Sensor Electrical Signal 240 are input signals to Electronic Control 245, as is Electrical Power Input 250 which may be typically 28 volts direct current (VDC) in aircraft applications. The output of Electronic Control 245 is Electronic Control Output Signal 255, which controls Solenoid Operated Pneumatic Valve 260 on Molecular Sieve Oxygen Concentrator 265.
The product gas output of Molecular Sieve Oxygen Concentrator 265 is routed to the aircrew by Oxygen Concentrator Output Distribution 270. Aircrew distribution points are shown by Aircrew Delivery Point(s) 295. The aircrew are normally in a pressurized cabin, and the division between pressurized and unpressurized areas is shown as Pressurization Demarcation Line 293. Oxygen Concentrator Output Distribution 270 also routes the product gas output of Molecular Sieve Oxygen Concentrator 265 to Oxygen Monitor 280 which generates Oxygen Monitor Output Signal 285. Oxygen Monitor 280 is utilized to determine the extent of oxygen enrichment present at Oxygen Concentrator Output Distribution 270 by measurement of a product sample present at the output of First Restrictive Orifice 275. Either separately or integrally to Oxygen Monitor 280, Solenoid Operated Vent Valve 290 is pneumatically connected to Oxygen Concentrator Output Distribution 270 and electrically connected via Oxygen Monitor Output Signal 285 to Oxygen Monitor 280.
Molecular Sieve Oxygen Concentrator 265 operates in the standard pressure swing manner. Molecular Sieve Oxygen Concentrator 265 contains two or more beds, not shown here. Air is alternately supplied at pressure to each bed with the other (desorbing) bed connected to First Atmospheric Vent 220 by the positioning of Solenoid Operated Pneumatic Valve 260. The internal positioning of Solenoid Operated Pneumatic Valve 260 determines which bed of Molecular Sieve Oxygen Concentrator 265 is connected to First Atmospheric Vent 220, with internal positioning of Solenoid Operated Pneumatic Valve 260 being controlled by Electronic Control 245 via Electronic Control Output Signal 255. The desorbing bed is also provided with a purge flow of oxygen enriched product gas (not shown) to assist desorption. Electronic Control 245 controls the bed cycling rate of Molecular Sieve Oxygen Concentrator 265 in response to both Inlet Supply Air 215 pressure and temperature. Preferably the bed cycling rate will be controlled proportionally to pressure, with an extreme temperature override switching function. Alternatively a cycle rate which is fixed at finite points rather than proportional can be used, offering simplicity at the expense of some accuracy.
Product gas delivered by Oxygen Concentrator Output Distribution 270 to Aircrew Delivery Point(s) 295 is continuously monitored by Oxygen Monitor 280 which also senses cabin pressure and generates Oxygen Monitor Output Signal 285, which switches Solenoid Operated Vent Valve 290 for connectivity with Second Atmospheric Vent 292 as required. Second Restrictive Orifice 291 is fixed to that value which, at maximum desired pressure in Oxygen Concentrator Output Distribution 270, will reduce the oxygen enrichment present in Oxygen Concentrator Output Distribution 270 to at least the upper limit of the specified concentration curve (Refer to FIG. 3, discussed below) even with very low aircrew breathing demand. A second switch point, well above the lower allowable limit, closes Solenoid Operated Vent Valve 290 to assure physiologically safe product concentration delivery to Aircrew Delivery Point(s) 295. FIG. 3 presents a graph of maximum and minimum allowable concentrations of oxygen as a function of aircraft cabin altitude, in order to illustrate the varying oxygen pressure requirements of an OBOGS aircraft system.
Electronic Control 245 is presented in more detail in FIG. 4 and FIG. 5. Referring to FIG. 4, Air Pressure Input 415 is the Inlet Air Supply 215 of FIG. 2. Air Pressure Transducer 420 is an embodiment of Inlet Supply Pressure Sensor 230 of FIG. 2. Temperature Thermistor 470 is an embodiment of Inlet Supply Temperature Sensor 225 of FIG. 2. Reference Voltage 425 represents a stable direct current (DC) voltage utilized as a fixed reference value for circuit operations. The pressure of Air Pressure Input 415 is translated by Air Pressure Transducer 420 to an electrical signal Pressure Transducer Output Signal 421. Pressure Transducer Output Signal 421 is routed to the input of First Signal Amplifier 430. The output of First Signal Amplifier 430 is combined with the outputs of First Nonlinear Amplifier 460 and Second Nonlinear Amplifier 465 in a manner discussed below. Maximum Pressure Reference Voltage 440 is generated from Reference Voltage 425 and is utilized as a maximum pressure limit reference voltage for First Nonlinear Amplifier 460. Minimum Pressure Reference Voltage 450 is generated from Reference Voltage 425 and is utilized as a minimum pressure limit reference voltage for Second Nonlinear Amplifier 465. First Nonlinear Amplifier 460 and Second Nonlinear Amplifier 465 serve to limit the voltage excursions of Pressure Analog Output 485 to a range representative of the lowest and highest pressures desired in the OBOGS system output. Within the pressure range between these limits, the value of Pressure Analog Output 485 is as determined by the output of First Signal Amplifier 430. Pressure Analog Output 485 is thus a range of voltage limited to maximum and minimum values related to maximum and minimum pressures at Air Pressure Input 415, while being continuously variable within the range. Air Temperature Input 472 is the temperature of Inlet Air Supply 215 of FIG. 2. Temperature Thermistor 470, a transducer element, produces an electrical signal which is representative of this temperature. The output of Temperature Thermistor 470 is routed to Second Signal Amplifier 475. Second Signal Amplifier 475 outputs a signal linearly related to temperature at Temperature Analog Output 480.
Referring to FIG. 5, Temperature Analog Output 480 and Pressure Analog Output 485 drive the circuitry 510 of FIG. 5. Temperature Analog Input 480 and Pressure Analog Input 485 are summed together to form Analog Sum signal 525. Analog Sum 525 is routed to Voltage-to-Frequency Converter 530. The output signal of Voltage-to-Frequency Converter 530 is a frequency which is linearly related to the value of Analog Sum 525. The output signal of Voltage-to-Frequency Converter 530 is applied to the input of Frequency Divider 535. Frequency Divider 535 serves to divide the frequency output of Voltage-to-Frequency Converter 530 by a fixed amount. The fixed divide ratio of Frequency Divider 535 is chosen such that the on and off time intervals at the output of Frequency Divider 535 allow the desired system transient response. The output of Frequency Divider 535 is applied to Switch 540. The output of Switched Load 545 controls the operation of Solenoid Operated Pneumatic Valve 260 in FIG. 2.
Solenoid Operated Vent Valve 290 in FIG. 2 is presented in more detail in FIG. 6. Solenoid Operated Vent Valve 290 is composed of Valve Assembly 635 and Restrictive Orifice 625. Product Delivery Input 620 represents a connection to Oxygen Concentrator Output Distribution 270 of FIG. 2. Restrictive Orifice 625 is analogous to Second Restrictive Orifice 291 of FIG. 2. Atmosphere Vent 630 is analogous to Second Atmospheric Vent 292 of FIG. 2. Electrical Solenoid 640 represents an electrical control from Oxygen Monitor Output Signal 285 of FIG. 2.
The control of gaseous venting by Solenoid Operated Vent Valve 290 is on-off in nature, and is controlled by the signal at Electrical Solenoid 640. This signal is proportional to oxygen partial pressure. When the oxygen partial pressure is greater than approximately 240 mm Hg (Mercury). Valve Assembly 635 will open and deliver full pressure from Product Delivery Input 620 to Atmosphere Vent 630 through Restrictive Orifice 625. This bleeds off product flow at a high rate which will cause sufficient nitrogen breakthrough in the concentrator beds to reduce the product oxygen concentration. At the lower switch point, approximately 220 mm Hg., the control signal to Electrical Solenoid 640 causes Solenoid Operated Vent Valve 290 to close, thereby allowing oxygen concentration to increase.
The details for one example of an apparatus that implements Solenoid Operated Pneumatic Valve 260 are presented in the linear valve mechanical illustration of FIG. 7. Valve System 710 is composed of Solenoid 712 and Linear Valve Assembly 722. Solenoid 712 is a control element which provides control of Linear Valve Assembly 722. Solenoid 712 is a "4-way solenoid" of the type known in the art and is utilized in this preferred embodiment to illustrate a method of linear valve control; other control means, solenoid or otherwise, may be used without departing from the spirit and scope of the invention. Linear Valve Assembly 722 has the following elements: System Air Inlet 724, Leaf Spring 726, Poppet 728, First Piston 730, Second Piston 734, Second Bed Connection 736, Bed Vent Connection 738, First Bed Connection 740, Air Inlet Sample Port 742, Second Piston Connection 748 and First Piston Connection 750. Solenoid 712 has the following elements: First Valve Vent 714, Second Valve Vent 716, Valve Connection 718, Valve Connection 720 and Common Connection 744. Electrical signal 713 is used to control Solenoid 712 in the usual manner. System Air Inlet 724 is connected to the system air supply. System air is supplied to the internal chamber of Linear Valve Assembly 722 by System Air Inlet 724. Leaf Spring 726 is used to hold Poppet 728 against Poppet Contact Surface 732. Poppet 728 is free to slide along Poppet Contact Surface 732, as indicated by the dashed lines of Poppet Alternate Position 752. Second Piston 734 and First Piston 730 are connected to opposing ends of Poppet 728 by a solid member 733 internal to Linear Valve Assembly 722.
Second Piston Connection 748 is connected to Connection 718 of Solenoid 712. Air Inlet Sample Port 742 is connected to Common Connection 744 of Solenoid 712. First Piston Connection 750 is connected to Valve Connection 720 of Solenoid 712, and Second Valve Vent 716 and First Valve Vent 714 are connected to system vents (not shown). When in the position shown, Second Piston 734 will receive pressurized air from Air Inlet Sample Port 742 via Common Connection 744, Valve Connection 718 and Second Piston Connection 748. As shown, First Piston 730 is vented to Valve Vent 714 via Valve Connection 720 and First Piston Connection 750. This causes Poppet 728 to move toward the First Piston 730 end, as shown by the dark poppet shading. When Solenoid 712 is placed in the opposite state by Electrical signal 713, Valve Connection 718 is connected to Second Valve Vent 716, Common Connection 744 is connected to Valve Connection 720, and First Valve Vent 714 is disconnected from Valve Connection 720. This allows Second Piston 734 to vent to Second Valve Vent 716 via Valve Connection 718 and Second Piston Connection 748, and First Piston 730 to receive pressurized system air from System Air Inlet 724 via Air Inlet Sample Port 742 and Common Connection 744. First Valve Vent 714 is not connected internal to Solenoid 712.
When the pressure differential across First Piston 730 is varied by varying Electrical signal 713 from a first state to a second state or vice versa, Poppet 728 will slide from its current position along Poppet Contact Surface 732 to Poppet Alternate Position 752. Thus a pressure differential across First Piston 730 will cause Poppet 728 to move from First Piston Connection 750 to Second Piston Connection 748. As Poppet 728 slides along Poppet Contact Surface 732 as described, Bed Vent Connection 738 is connected to First Bed Connection 740 or to Second Bed Connection 736 through the trapped gas volume existing between Poppet 728 and Poppet Contact Surface 732.
Bed Vent Connection 738 is connected to a system vent. First Bed Connection 740 is connected to an air purification system bed (not shown), and Second Bed Connection 736 is connected to another air purification system bed (not shown). A first position of Poppet 728 is depicted by the dark shading in FIG. 1, and the second, opposing position of Poppet 728 is shown by the dashed lines of Poppet Alternate Position 752. As Electrical signal 713 varies, Solenoid 12 causes the linear valve internal pistons 730 and 734 to be set to either fixed end position. Therefore, the valve cycle rate of linear valve system 10 is simply controlled as a function of varying Electrical signal 713.
With Poppet 728 in the position shown in FIG. 7, connectivity is achieved between First Bed Connection 740 and Bed Vent connection 738. Both sides of Second Piston 734 are connected to System Air Inlet 724 and there is no pressure differential across Second Piston 734. One side of First Piston 730, however, is connected internally to System Air Inlet 724 and the opposite side of the piston is connected to First Piston Connection 750. First Piston Connection 750 in turn is connected to First Valve Vent 714 so that the pressure differential across First Piston 730 is the difference in pressure between System Air Inlet 724 and First Valve Vent 714.
Alternately, when the internal connections of Solenoid 712 are reversed as described previously, there is a pressure differential across Second Piston 734 and no pressure differential across First Piston 730 with the result that Poppet 728 slides along Poppet Contact Surface 32, towards Second Piston 734, to Poppet Alternate Position 752. As Poppet 728 moves to Poppet Alternate Position 752 connectivity is achieved between Second Bed Connection 736 and Bed Vent Connection 738. Connectivity, however, is never present between Second Bed Connection 736 and First Bed Connection 740. This is due to the fact that Poppet 728 is made of a self-lubricating material, such as plastic, which is machined and lapped to a high degree of flatness and finish, and Poppet Contact Surface 732 is also produced with a high degree of flatness and finish. Additionally, Leaf Spring 726 enforces the contact made between Poppet 728 and Poppet Contact Surface 732.
The valve system disclosed in FIG. 7 offers significant advantages over prior art valves. First, prior art valve applications, such as air purification systems, typically use rotary valves having gear motors. Such valves are expensive because of the gear motor apparatus, and typical prior art air purification systems may require a significant number of rotary valves. The valve system of FIG. 7 does not use gear motors for operation, and thus is more economical. Second, the valve cycle rate is easily controllable. This is in contrast to prior art valves which utilize gear motors and thus have a valve cycle rate determined by the RPM characteristics of the gear motor. This places an undesirable restriction on gas flow system design. The present invention describes a valve which does not employ a gear motor for operation. Thus the valve of the present invention has a controllable variable cycle rate which is not related to the RPM characteristics of a gear motor. Additionally, because the linear valve does not use gear motors, it is much cheaper to manufacture and maintain.
FIG. 8 depicts test results of a developmental OBOGS system constructed in accordance with the foregoing description of the present invention. From this data it can be seen that the oxygen partial pressure is maintained within the required range at all altitudes at the projected minimum inlet pressure (idle power) settings, and air usage is limited to approximately 1.0 lb. per minute at all conditions. Determination of the control means of the present invention was based on this and related test data which clearly showed system advantages in response time and accuracy over prior art system approaches.
A basic feature of the present invention is that adsorbing bed cycling rate varies as a function of the supplied air gage pressure, from about 10 seconds/cycle at 18 PSIG to 5 seconds/cycle at 5 PSIG, and this automatically limits air usage while optimizing performance. These two seemingly contradictory functions occur because of four factors. First, the bed geometry is designed for a minimum "dead" volume (volume in excess of sieve) which is pressurized and then lost during desorption each cycle. The higher the pressure, the more volume that is lost. Second, purge cross flow is precisely sized at the highest controlled operating pressure, 18 PSIG in this case, to meet all requirements with minimum purge flow. Third, the control valve is designed for rapid movement to full opening and minimum pressure drop, thereby allowing rapid cycling. Four, a type of molecular sieve best suited for rapid pressure swing adsorption is used. 18 PSIG is the upper limit setting, and higher pressures do not reduce the absorbing bed cycling rate below 10 seconds/cycle.
Another feature of the present invention is that the electrical signal from the temperature sensor also varies cycling rate as a function of the temperature of the air supplied, over a range of approximately +10/-20% at 140 degrees Fahrenheit to approximately +10/-20% at -20 degrees Fahrenheit. This improves operation at both temperature extremes without exceeding air usage goals, since bed adsorption is a function of temperature and the oxygen output will follow the same trend. Yet another feature of the present invention is that the composition control can be of the bang--bang type in order to maintain oxygen at the 60% level.
It can be seen from the above discussion that the present invention provides a control means for molecular sieve on-board oxygen generating systems which provides increased efficiencies while providing operation from inlet supply sources having limited supply and pressure capability.
While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. For instance, while the OBOGS is directed to generating oxygen, other gases or gaseous mixtures may be generated by the gas generating system of the present invention. | A control device for molecular sieve on-board oxygen generating systems measures both temperature and pressure of the inlet air of an oxygen generating system. An electronic control unit applies pressure limits to a pressure measurement signal and combines it with a temperature measurement signal to produce a composite analog signal responsive to both temperature and pressure inlet air conditions. This analog signal is linearly converted to a frequency signal, whereupon the frequency signal is divided by a constant in order to produce a drive signal for control of the absorb/vent bed cycle valves. Composition control is achieved by venting product mixture as required. Inlet air pressures down to 5 PSIG (pounds per square inch gauge) produce correct system operation, and the quantity of conditioned air required is automatically limited so that system efficiency is higher than prior art systems. | 1 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application is a divisional of application Ser. No. 11/376,898 filed on Mar. 16, 2006, entitled “ENHANCED AC IMMUNITY IN GROUND FAULT DETECTION” (pending) which is hereby incorporated herein by reference.
BACKGROUND
[0002] In many telecommunications applications, repeaters and other electronic devices are housed in remote units scattered throughout a geographical region in the vicinity of a central office. In one example, a remote unit communicates with the central office and also receives power from the central office through the same cable or other communication medium. This cable is also referred to as a “span cable,” “plant,” or “cable plant.” An example of a span cable includes a set of twisted-pair conductors over which telecommunications data is transferred between the central office and the remote units, and over which DC power is supplied by the central office to the remote unit.
[0003] The remote unit typically utilizes the power received from the central office over the span cable to power one or more electronic devices within the remote unit. The power delivered via a span cable is often susceptible to disturbances (such as faults, voltage spikes and surges) caused by environmental factors such as lighting and nearby electrostatic discharges. Left unmitigated, such power disturbances can interrupt telecommunications operations and permanently damage equipment.
[0004] Many electrical protection and personnel safety systems have been developed to detect these disturbances. One such system is generically referred to as ground fault detection system. With ground fault detection, the system looks for excessive current flowing to ground. When such current is detected, the ground fault detection system takes appropriate action such as shutting down the power supply that transmits power over the span cable.
[0005] AC power lines are often located within the vicinity of the span cable or plant of the telecommunications network. The signals on the AC power lines can adversely affect signals on the span cable through a phenomenon known as “AC induction.” With AC induction, an AC signal from the power lines or other source of AC power is induced onto the copper plant. When the electronic devices of the network are separated by a large distance, the plant is more susceptible to AC induction.
[0006] AC voltages typically are induced longitudinally upon span cables which cause currents to flow through the longitudinal noise filter circuits to ground at both the Central Office Terminal (COT) and Remote Terminal (RT) equipment. The earth ground maintained between the COT and RT installation completes the circuit, allowing the induced voltage to maintain current flow in the communication systems grounding path. The longitudinal noise filter circuits present a relatively high impedance to ground at the AC power line frequencies to avoid large currents from flowing in the filters ground path, as would be the case in a direct contact of an AC power line with the span cable (known as a power cross event). The ground fault detection circuit is designed to monitor the level of DC current flowing in the grounding system as the result of leakage currents to ground along the cable span and equipment. AC induction currents are imposed on the DC leakage currents and can look like a ground fault to the ground fault detection circuit during the half of the AC cycle which is additive to the DC current. Thus, the AC induced signal could trip the ground fault detection circuit causing the power supply to be inadvertently turned off. This could be compensated for with a large filter, e.g., a large capacitor, in the ground fault detection circuit to filter out the AC signal. However, the filter would have to be prohibitively large and expensive due to the large voltages involved. Further, if a large capacitor is incorporated into the ground fault detection circuit, any alternating longitudinal voltage on the span would be exposed to a low (longitudinal) impedance to ground. If the power lines came into direct contact with the cable plant of the telecommunications network, the power lines would be shorted to ground through the network device. Software filters have also been used to attempt to address this phenomenon. However, the effectiveness of software filters tend to roll off at higher frequencies. It has been discovered that some of the most relevant frequencies for AC immunity are harmonics that fall outside the effective range of traditional software filters.
[0007] Therefore, there is a need in the art for enhanced AC immunity in ground fault detection.
SUMMARY
[0008] Embodiments of the present invention provide improvements in ground fault detection in a central office terminal. More specifically, in one embodiment, a method for reducing the occurrence of false ground fault detections in a central office terminal is provided. The method includes generating a no-fault signal when no ground current is detected, delaying generation of a fault signal when ground current is detected at least for the duration of an expected pulse in AC induced signal, and when the ground current persists for a sufficient period, generating a signal indicating a fault condition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a block diagram of a telecommunications system with enhanced AC immunity for ground fault detection according to one embodiment of the present invention.
[0010] FIG. 2 is a block diagram of one embodiment of an AC immunity circuit according to one embodiment of the present invention.
[0011] FIGS. 3A and 3B are timing diagrams illustrating one embodiment of a process for providing AC immunity to a ground fault detection circuit.
[0012] FIGS. 4A and 4B are timing diagrams illustrating one embodiment of a process for detecting a ground fault with a ground fault detector with increased AC immunity.
DETAILED DESCRIPTION
[0013] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific illustrative embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical and electrical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense.
[0014] Embodiments of the present invention provide enhanced AC immunity in ground fault detection circuits to avoid problems with AC induced signals on telecommunication lines. Some embodiments use an AC immunity circuit that conditions the output of the ground fault detection circuit in a manner that stretches out AC pulses in the ground fault detection signal to reduce the chances of a false ground fault detection.
[0015] FIG. 1 is a block diagram of one embodiment of a telecommunications system 100 with enhanced AC immunity to ground fault detection. The embodiment of system 100 is a four wire digital subscriber line communication system the includes a central officer terminal 102 and a remote terminal 104 coupled together over a communication medium 105 comprising two twisted copper pairs 106 and 108 . In other embodiments, the teachings of the present application with respect to AC immunity are applied to other systems that use copper wires exposed to potential electrical disturbances, e.g., single pair systems.
[0016] In this embodiment, the central office terminal 102 provides power to and communicates data with the remote terminal 104 . The central office terminal 102 includes communication circuits 110 and 112 that communicate data with corresponding communication circuits 114 and 116 , respectively, over twisted copper pairs 106 and 108 . In one embodiment, these communication circuits communicate data using high bit rate digital subscriber line (HDSL), asymmetric digital subscriber line (ADSL), G.SHDSL, or any other appropriate xDSL or other communication protocol.
[0017] Central office terminal 102 also includes power supply 118 that provides power over communication medium 105 to power remote terminal 104 . Power supply 118 includes two outputs PS+ and PS−. The output of power supply 118 is typically a negative voltage on the order of −190VDC. The power supply 118 injects the power signal on the communication medium through transformers 120 and 122 that are coupled to PS+and PS−, respectively. The power is received in remote terminal 104 at power supply 124 . Power supply 124 is coupled to communication medium 105 through transformers 126 and 128 . Power supply 124 typically reduces the voltage level received from power supply 118 for use by the circuits of remote terminal 104 , e.g., communication circuits 114 and 116 .
[0018] Central office terminal 102 also includes circuitry that is designed to protect the central office terminal 102 from damage due to electrical surges caused by various natural phenomenon, e.g., lightning strikes. The circuitry 113 appears at each interface of the twisted copper pairs 106 and 108 and is connected to ground 131 . Protection circuitry 113 activate as surge voltages rise above the trigger threshold of the protection devices used and conduct away large amounts of surge currents, thus reducing the surge voltages seen by the end terminal equipment 102 and 104 . Further protection and personnel safety circuitry includes a ground fault detector 130 , an AC immunity circuit 132 and a processor 134 . The ground fault detector 130 is coupled to the power supply signals PS+ and PS− and is adapted to determine when a current to ground 131 exceeds a selected threshold. When such a condition is detected, the ground fault detector 130 produces a signal that indicates a ground fault condition has occurred. Unfortunately, the ground fault detector 130 may provide a false indication of a fault condition due to AC induced signals on the communication medium 105 . Thus, the signal from ground fault detector 130 is conditioned to reduce the likelihood of a false indication of a ground fault condition.
[0019] This embodiment uses a combination of circuit elements to reduce the potential for false indications of a ground fault due to AC induced signals on communication lines 105 . Central office terminal 102 includes, for example, a combination of software and hardware filtering along with circuitry that extends AC pulses in the output of ground fault detector 130 . In one embodiment, the hardware filter comprises a capacitor built into the ground fault detector. An example of this type of hardware filter is shown and described below with respect to FIG. 2 . Further, the software filtering is typically implemented in processor 134 .
[0020] AC immunity circuit 132 implements the pulse extender functionality. For example, AC immunity circuit 132 receives the ground fault signal from ground fault detector 130 . When AC current is present, periodic pulses corresponding to the various harmonics of the AC fundamental frequency occur in the signal from ground fault detector 130 . The AC immunity circuit 132 stretches out the pulses for a period of time sufficient to allow the software filtering of processor 134 to prevent a false indication of a ground fault condition caused by the higher harmonic pulse rates which exceed the software filters sampling capability. In one embodiment, the AC immunity circuit 132 stretches out the portion of the AC signal that indicates no fault condition such that the output of ground fault detector 130 is conditioned to remain in a no fault state for a prolonged period.
[0021] Processor 134 over-samples the output of AC immunity circuit 132 periodically to determine if there is a ground fault in the communications system. Without AC immunity circuit 132 or a software filtering means, the processor 134 was prone to false detection of ground faults because it could sample the signal from the ground fault detector in a low state (active state) caused by the pulses from the AC induced signal. With some software filtering means, this problem was partially solved, e.g., at lower harmonic frequencies. However, due to the presence of higher harmonics in the AC induced signal, e.g., harmonics above 180 Hz (especially at 540 Hz and 900 Hz), the software filtering could not achieve the sampling rate to eliminate the problem. With the addition of AC immunity circuit 132 , the effective sampling rate of the processor is increased beyond the harmonic frequencies of the AC induced signal, thereby improving the accuracy of the ground fault detection circuit.
[0022] FIG. 2 is a block diagram of one embodiment of a ground fault detector 200 and an AC immunity circuit 202 for use in a central office terminal, e.g., central office terminal 102 of FIG. 1 . AC immunity circuit 202 conditions the output of ground fault detector 200 so as to reduce the effect of AC induced signals in the telecommunications system.
[0023] Ground fault detector 200 detects ground fault conditions. Ground fault detector 200 includes transistor 204 and resistor 206 . Resistor 204 is coupled to the supply signal PS+. In most embodiments, the PS+ signal is referenced to ground such that all power signals in the system are below ground potential to prevent corrosion as is known in the art. Resistor 206 is also coupled to the emitter of transistor 204 . The collector of transistor 204 is coupled to chassis ground, e.g., earth. The base of transistor 204 is coupled to the PS− signal through resistor 210 . Ground fault conditions cause current to flow in resistor 206 and transistor 204 . This current is used to indicate a ground fault condition when it rises above a selected level.
[0024] Ground fault detector 200 also includes an optocoupler 208 that is coupled to the base of transistor 204 and the PS+ signal. Optocoupler 208 is turned on when current above a selected level flows to earth through resistor 206 and transistor 204 . When this condition is detected, the output of optocoupler 208 transitions to a low output voltage to indicate the fault condition.
[0025] When an AC signal is induced on the communication medium, e.g., communication medium 105 of FIG. 1 , this signal causes an AC current to flow in resistor 206 and transistor 204 . Thus, on one-half of the AC cycle of the induced signal, optocoupler 208 is turned on and on the other half the cycle optocoupler 208 is turned off. If left unmitigated or filtered, this AC signal can lead to false indications of a ground fault in ground fault detector 200 .
[0026] Ground fault detector 200 includes a hardware filter that is used to at least partially address this problem. The hardware filter, in this embodiment, comprises capacitor 212 coupled across resistor 206 and transistor 204 . Unfortunately, the value of capacitor 212 cannot be made large enough to fully remove the AC components because such a capacitor would provide a dangerous low impedance path to ground and prevent proper electrical protection circuit function. Further, such a capacitor would be prohibitively large and expensive due to the low frequencies involved with AC signals. Capacitor 212 can be made of sufficient size to provide sufficient filtering of only the highest frequency harmonic components (above 1020 Hz) of the AC induced signal. The lower and middle frequency components (60 Hz through 900 Hz) are addressed through pulse extension and software filtering.
[0027] Pulse extension is accomplished in AC immunity circuit 202 . AC immunity circuit 202 is coupled to the output of ground fault detector circuit at node 214 . AC immunity circuit 202 conditions this signal at node 214 and provides an output at node 216 .
[0028] In one embodiment of AC immunity circuit 202 includes a comparator 218 that compares a reference voltage at input 220 with a signal at input 222 . The reference voltage is established by a voltage divider comprising resistors 221 and 223 and power supply 225 . The signal at input 222 is the signal from node 214 with pulses caused by induced AC.
[0029] AC immunity circuit 202 extends the pulses in the signal at node 214 using two signal paths with different time constants. The two signal paths control the charging and discharging of capacitor 224 . The first signal path charges capacitor 224 . The first signal path includes resistor 226 and diode 228 . Resistor 226 is coupled between node 214 and a power supply 225 , e.g., a 3.3 V supply. Diode 228 is coupled between node 214 and node 222 . Capacitor 224 is coupled between node 222 and ground.
[0030] The second signal path controls the discharging of capacitor 224 . The second signal path includes resistor 230 coupled between nodes 214 and 222 . Resistor 230 has a resistance value that is substantially greater than resistor 226 . This difference in resistance values controls the difference in time constants between the two paths. In one embodiment, resistor 226 is 10 KΩ and resistor 230 is 75 KΩ.
[0031] The operation of the circuit of FIG. 2 is described with respect to the timing diagrams of FIGS. 3A , 3 B, 4 A, and 4 B. FIGS. 3A and 3B illustrate the conditioning effect of AC immunity circuit 202 on the output of ground fault detector 200 in the presence of an AC induced signal. Further, FIGS. 4A and 4B illustrate the manner in which AC immunity circuit 202 processes a signal without an AC induced component.
[0032] FIG. 3A illustrates a signal at node 214 when an AC signal is induced on the communication medium, e.g., communication medium 105 of FIG. 1 , by a co-located power line. At time T 1 , the ground fault detector signal 214 is at a high voltage level corresponding to the time where the induced AC current opposes the DC leakage current, resulting in a net current below the selected level of the ground fault detector. At time T 2 , the signal output by the ground fault detection circuit transitions to a low voltage which corresponds to the point where the induced AC current becomes additive to the DC leakage currents and exceeds the selected level of ground fault detector 200 . In the absence of AC induction, a continuous low voltage state of this signal would indicate that a DC ground fault has been detected.
[0033] During this cycle (between T 2 and T 3 ), the voltage at node 214 is grounded and the capacitor 224 is enabled to discharge through resistor 230 , e.g., through the second signal path. Because the time constant of the second signal path is much longer than the time constant of the first signal path, the voltage at node 222 does not change significantly before it is recharged as described below.
[0034] The first signal path of AC immunity circuit 202 maintains the no fault state during the other half of the AC cycle of the signal at node 214 . At time T 3 , the signal shown in FIG. 3A returns to a high voltage level. This turns on the diode 228 and allows the capacitor 224 to be charged from voltage source 225 through resistor 226 and diode 228 . Because the resistor 226 is selected with a lower resistance value, the capacitor is quickly charged up to a level sufficient to maintain the indication of no fault condition.
[0035] The AC immunity circuit 202 produces the conditioned ground fault detection signal based on the voltage across capacitor 224 appearing, at node 222 which is the input to comparator 218 . A sample of comparator 218 output at node 216 of AC immunity circuit 202 is shown in FIG. 3B . As can be seen in FIG. 3B , the output voltage at node 216 remains constant at a level indicating no fault despite the AC induced signal on the communication lines. The voltage at node 222 is maintained above the reference voltage set at node 220 by the resistor divider. Thus, comparator 218 produces the high voltage output at node 216 . This indicates to the processor that there is no fault despite the AC induced signal.
[0036] When the DC leakage current increases above the selected level, a true DC ground fault conditions occurs. Increased DC leakage current decreases the high times and increases the low times in signal 3 A, allowing the second signal path of AC immunity circuit 202 to discharge capacitor 224 . The resulting voltage on node 222 falls below the selected level on node 220 forcing comparator 218 output 216 to go low, AC immunity circuit 202 produces a slightly delayed signal indicating the ground fault condition as shown in the timing diagrams of FIGS. 4A and 4B . This delay is caused by the time constant of the second path in AC immunity circuit 202 that compensates for the AC induced signal. In this example, a ground fault occurs at time T 5 . At time T 5 , the signal from the ground fault detector transitions from a high (no fault) condition to a low (fault) condition. At this time, diode 228 is turned off and capacitor 224 is slowly discharged through resistor 230 . When the capacitor voltage drops below the reference voltage at node 220 , the comparator 218 trips and changes the output at node 216 to a low voltage level indicating a ground fault at T 6 .
[0037] It is noted that the described embodiments have used a low voltage level to indicate a fault condition. It is understood that in other embodiments, a fault condition is indicated by a high voltage signal. Further, capacitors 242 and 244 are standard bypass noise capacitors. In one embodiment, resistor 250 is included as a pull-up resistor because comparator 218 is open collector. Further, optional resistor 248 can be included to add hysteresis to comparator 218 , but, it is not necessary to improve noise performance. Further, with the use of AC immunity circuit 202 , the processor, in some embodiments, does not implement a software filter on the output of AC immunity circuit 202 .
[0038] In another embodiment, AC immunity circuit 202 extends any AC pulse that is present in the output of the ground fault detector 200 through the use of a retriggerable monostable timer to decrease the chances of a false positive indication of a ground fault. The pulse is extended at least for the duration of the low voltage cycle of the AC induced signal. In one embodiment, the pulse is stretched past the edge of the next sampling period. This effectively raises the bandwidth of the software filter. | A method for reducing the occurrence of false ground fault detections in a central office terminal is provided. The method includes generating a no-fault signal when no ground current is detected, delaying generation of a fault signal when ground current is detected at least for the duration of an expected pulse in AC induced signal, and when the ground current persists for a sufficient period, generating a signal indicating a fault condition. | 7 |
This is a continuation of application Ser. No. 787,005, filed Oct. 10, 1985, which was a continuation of application Ser. No. 443,798 filed Nov. 22, 1982, both now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to a charge-coupled device comprising at a surface of a semiconductor body a system of juxtaposed parallel channels and a series output register of which successive charge storage and transfer elements are each associated with a parallel channel, which system of parallel channels comprises two sub-groups so arranged that the parallel channels belong alternately to a first and to a second sub-group, and in which there is provided at the area of transition from the parallel channels to the series output resistor an electrode system by means of which a row of charge packets transported through the parallel channels can be divided into two sub-rows which correspond to the two sub-groups and which can be introduced successively into the series output register, said electrode system comprising first and second comb-shaped electrodes and first and second strip-shaped control electrodes, the first comb-shaped electrode having a cross-bar in the form of a strip extending transversely across the parallel channels and having teeth which extend from the cross-bar in the direction of charge transport above the parallel channels of the first sub-group, the second comb-shaped electrode having a cross-bar which near the tips of the teeth of the first comb-shaped electrode extends transversely across the parallel channels and has teeth which are interdigitated with the teeth of the first comb-shaped electrode and extend above the parallel channels of the second sub-group into the proximity of the strip-shaped cross-bar of the first comb-shaped electrode, the first and second strip-shaped control electrodes extending transversely across the parallel channels and, viewed perpendicular to the surface, being present in the regions between the tips of the first comb-shaped electrode and the cross-bar of the second comb-shaped electrode, and in the regions between the tips of the second comb-shaped electrode and the cross-bar of the first comb-shaped electrode, respectively.
A known type of charge-coupled device having a system of parallel channels, the outputs of which are coupled to the parallel inputs of a series output register, is a series-parallel-series (SPS) memory. The parallel channels form a memory matrix for analog or digital information which is introduced via a series input channel and which can be read out via the series output channel. Another form of charge-coupled device of the above-described type is an image sensor in which the charge stored in the parallel section corresponds to a received two-dimensional radiation pattern. Although the invention can be used for such other forms of device and not merely in SPS-memories, it will nevertheless be described mainly with reference to SPS-memories due to the particular advantages for these important memory devices.
In conventional SPS-memories, the series channels are formed by 2-phase CCD's. Because in a 2-phase CCD one empty site must always occur per full charge storage site, it is apparent to choose the pitch between the parallel channels such that one parallel channel occurs in the series register per two charge storage transfer sites. Upon transferring a row of charge packets from the parallel section into the series channel, half of the storage sites in the series channels are occupied, so that the charge packets can be transported to the output in the usual manner.
A method of increasing the information density, known per se, for example, from U.S. Pat. No. 3,967,254, uses the principle of "interlacing" and "de-interlacing". The pitch between the parallel channels in comparison with the above-described construction may be chosen to be two times smaller so that one parallel channel occurs per charge storage/transfer site of the series input register and/or the series output register. The information density or quantity of information can thus be substantially doubled. Because only half of the site of the series channels can be occupied simultaneously, the information can no longer be read in or read out per column. Therefore, upon reading in, for example, first the even sites of a row are occupied with information and then, in a second step, the odd sites (interlacing). Analogously, when reading out a row, first the charge packets, for example, on the even sites are introduced and read out in the series output channel and then the information in the odd sites (de-interlacing) are introduced and read out.
The electrode system configuration at the parallel-to-series transition which as specified in the above comprises two interdigitated combs is known inter alia from the already-mentioned U.S. Pat. No. 3,967,254, and serves for de-interlacing the stored information. Its operation thereof is basically as follows: first a complete row of signal charges is moved below the said first comb-shaped electrode. The signals then alternate below a tooth and below a region below the cross-bar of the comb-shaped electrode. By means of the said first control electrode, the signals which are stored below the teeth of the first comb-shaped electrode can be moved via the regions below the cross-bar below the second comb-shaped electrode into the series-output register channel so as to be read out at the output. During this parallel-series transfer the signals, which are stored below the cross-bar of the first comb-shaped electrode, are not transferred since the first control electrode overlaps only the teeth and not the cross-bar of the first comb-shaped electrode. When the series output channel is again empty, the remaining signals can be moved below the teeth of the second comb-shaped electrode by means of the second control electrode and then again into the series-output channel.
In the last-mentioned transport, in which the charge is moved from below the teeth into the series-output channel, the electrode structure may give rise to problems. In case of small quantities of charge the charge transfer consists substantially of thermal diffusion in which the charge (on the source side) moves asymptotically to zero along an exponential curve as a function of the time t with a time constant τ=4L 2 ·(π 2 D) -1 . In this formula L is the length of the electrode on the source side and D is the diffusion constant. Because the length L of the teeth generally is large, the charge transport will be rather inert. In a specific embodiment in which L at the area of the teeth is more than twice as large as the cross-bars of the comb-shaped electrodes (and, the lengths L of the remaining clock electrodes), the time constant T becomes more than 4 times as large.
The comb-configuration of the de-interlacing electrodes therefore has a detrimental influence on the frequency properties of the memory, in particular in those cases in which the further dimensions are chosen to be as small as possible.
SUMMARY OF THE INVENTION
One of the objects of the invention is to mitigate this disadvantage at least for the greater part and it is inter alia based on the recognition of the fact that loss of time can be prevented by causing the slow charge transport to take place at least substantially in the time interval in which the first sub-row of the series-output channel is transported.
According to the invention, a charge-coupled device having the features specified above is characterized in that a third strip-shaped control electrode is provided between the said electrode system and the channel of the series output register, extends transversely across the parallel channels and forms with the underlying parts of the parallel channels and forms with the underlying parts of the parallel channels a plurality of buffer storage sites in which, when a first sub-row of a row of charge packets is introduced into the series output register channel, the other sub-row can be stored before being introduced into the series output register channel when the series-output register channel is again empty.
As a result of the presence of the buffer electrode between the comb-shaped electrode structure and the series-output register channel, the slow charge transport may take place in the read-out time of the first sub-row. As a result of the comparatively long duration of said read-out time, said charge transport does not present any problems. Since the electrode length of the buffer electrode may be very small (it may at least be made much smaller than the length of the teeth) the transfer from the buffer electrode to the series output channel may be very fast. In a preferred embodiment in which the length L of the buffer is at least approximately two times smaller than the length L of the teeth, the charge transport may be approximately four times faster as a result of which the frequency properties of the parallel-series junction again become comparable to those in other parts of the memory.
BRIEF DESCRIPTION OF THE DRAWING
An embodiment of the invention will now be described by way of example with reference to the accompanying diagrammatic drawing, in which:
FIG. 1 is a plan view of a part of a semiconductor device in accordance with the invention;
FIGS. 2 to 4 are sectional views of the device as shown in FIG. 1 taken on the lines II--II, III--III, and IV--IV, respectively;
FIG. 5 shows a diagram of clock voltages to be applied; and
FIG. 6 shows a diagram of an SPS-memory.
It is to be noted that the Figures are diagrammatic and are not drawn to scale.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Although the invention is not restricted to SPS-memories but may also be used in other matrix-like structures, it will be described specifically with reference to an SPS-memory due to the particular interest of the invention for this class of devices. For that purpose, FIG. 6 shows a diagram of an SPS-memory device. The device comprises a series-input register A, a series-output register B and a parallel section C which is present between the registers A and B and which forms the actual memory matrix. The parallel section comprises a number of juxtaposed channels 1 of which only six are shown in FIG. 1 but of which the actual number will be much larger and may be a few hundred. The direction of the charge-transport in the channels 1 is considered to be from the top to the bottom in the drawing. Channel stopper regions 2 are formed between the channels 1 and isolate the channels 1 from each other. The charge transport in the parallel section is controlled by clock electrodes 3 to 8 extending transversely across the parallel section. The electrode 3 constitutes a transfer gate for transferring information from the series-input register A to the parallel section C. The electrodes 4 to 8 constitute a number of memory sites arranged in a matrix structure with the underlying semiconductor body. The electrodes 4 to 8 may form a 2, 3 or 4-phase system. Preferably, however, said clock electrodes are arranged to form a so-called multiphase system in, for example, groups of 10. As described inter alia in U.K. Patent Application No. 8224939, which corresponds to Dutch Application No. 8104102, nine out of ten successive storage sites in each group are filled with information, while the tenth remains empty. By moving the empty place from the top to the bottom the information can be moved from the top to the bottom step by step. The advantage of this mode of operation is the high information density which can be obtained in the parallel section in that only one empty site occurs in every ten sites.
It is to be noted that only a few clock electrodes of the parallel section are shown but that, of course, the whole memory matrix is covered with such electrodes.
The series-input register A comprises a 2-phase CCD ahving an input connection 9 for supplying the information to be stored in the memory, and clock electrodes 10 and 11. For simplicity, said electrodes are shown in FIG. 6 by single electrodes connected to one of the clock lines φ 1 and φ 2 . In practice, however, the electrodes are often composed of two parts which are electrically connected together at different metallization levels, as will be described hereinafter in the following embodiment. The register A forms a 2-phase CCD in which the electrodes 10 are connected, via the common clock line 12, to the clock voltage source φ 2 A and the electrodes 11 are connected to the clock voltage source φ 1 A via the clock line 13.
The output register B is likewise formed by a 2-phase CCD having an output contact 14 and electrodes 15 and 16 which are connected alternately via the clock lines 17 and 18, respectively, to 2-phase clock voltages φ 1 B , φ 2 B .
It is assumed that an asymmetry is provided below the electrodes 10, 11 and 15, 16, respectively, in such manner that upon applying clock voltages below the lefthand edges of the electrodes a potential barrier is formed as a result of which a 2-phase charge transport is effected from the left to the right. Such a known asymmetry may also be provided below the electrodes 4-8 in the parallel section.
In the FIG. 6 SPS-memory the pitch between the parallel channels 1 is chosen such that one parallel channel of the parallel section C corresponds to each stage (electrode) of the series registers A and B. In this manner a maximum information density can be obtained. Because, however, in the horizontal registers information can be stored only in every other electrode (in the 2-phase CCD the full sites are always alternated by an empty site) the writing or reading of a row of information does not take place in one time but in two successive steps. Upon writing, for example, first the sites below the electrodes 10 in the series input register A are filled. Via the transfer gate those signals are transferred below the first electrode 4 in the channels 1a. The input register A is then filled again with signals until all sites below the electrodes 11 are occupied; the signals introduced in the first step meanwhile remain below the electrode 4. The signals below the electrode 11 are then moved from the input register A in the parallel channels 1b below electrode 4 (interlacing). Now a complete row below the electrode 4 is filled with information which can be transported to the output register B in the usual CCD-manner in the form of a row.
Because the output register B as well as the input register A can hold at most only half a row, the signals of a row must be moved in the register in two successive steps to be read out. In FIG. 6 the electrode configuration for dividing the rows is shown diagrammatically and, for clarity, only partly. Viewed in the direction of charge transport said electrode configuration comprises a first comb-shaped electrode 19 having teeth 20 above the channels 1a, and a second comb-shaped electrode 21 having teeth 22 above the channels 1b. Two control or transfer gates are present above the combs which are not shown to avoid complexity of the drawing but one of which extends above the tips of the teeth 20 and the other of which extends above the teeth 22, as will become apparent from the description of the embodiment of FIGS. 1 to 4. A transfer gate 23 is present between the comb 21 and the series output register B.
A row of charge packets which is moved through the parallel section from the top to the bottom can be stored below the first comb 19. The charge packets below the teeth 20 in the channels 1a can then be further transported selectively to the read-out register B, while the charge packets remain in the channels 1b. When the read-out register B is again empty, the charge packets in the channels 1b can be transferred.
FIGS. 1 to 4 are a plan view and cross-sectional views, respectively, of a part of an embodiment of an SPS-memory according to the invention, namely a part which comprises the transition between the parallel section C and the output register B. It is to be noted that the same reference numerals as in FIG. 6 will be used as much as possible for corresponding components. In addition it is to be noted that, although the embodiment is of the n-type surface channel type, the invention is not restricted hereto, but may also be used in constructions having a p-type channel and/or in constructions of the buried channel type.
The device comprises a p-type semiconductor body 31, preferably of silicon. Of course, any other suitable semiconductor material may be used instead of silicon. The semiconductor body 1 comprises at least a surface layer 32 having a comparatively low doping concentration of between 10 15 and 10 16 acceptor atoms per cm 3 . This layer may cover the whole thickness of the semiconductor body but in another important embodiment it may also be provided as a comparatively high-ohmic layer having a thickness between 5 and 10 μm on a low-ohmic p-type substrate 33 having a doping concentration between 10 19 and 10 20 atoms per cm 3 . As is known, this construction of the semiconductor body has the advantage that the leakage currents can be restricted. in FIGS. 2 to 4 this possible composition is indicated by the broken lines separating the epitaxial layer 32 from the substrate 33.
The CCD channels 1a and 1b of the parallel section C and the channel of the output register B are defined in the p-layer 32 as well as the input register A not shown in the Figures. For this purpose, the surface of the semiconductor body has a field oxide pattern 2 (shown in broken lines in FIG. 1) which covers a large part of the surface and has openings at the area of the channels 1a, 1b, A and B. Of course, the field oxide pattern 2 may also have openings outside the part shown in the Figures in places where peripheral circuits are provided. The field oxide pattern 2, the thickness of which may be between 0.5 and 1 μm, is formed in the present embodiment by means of local oxidation of the silicon body. In order to prevent stray channel formation, the doping concentration below the oxide pattern 2 is increased by providing the p-type channel stopper zones 34.
The width of the channels 1a, 1b is, for example, approximately 5 μm, while the width of the field oxide strips 2 which separate the channels 1a and 1b from each other is approximately 2 μm.
At the area of the CCD-channels the surface of the semiconductor body is covered with a thin dielectric layer, for example with a silicon oxide layer 35 with a thickness between 0.05 and 0.07 μm. The clock electrodes in the form of a two-layer wiring are provided on the layer 35. The electrodes 15, 16 of the output register B each comprise an electrode portion 15a and 16a, respectively, of polycrystalline silicon (hereinafter referred to as poly) and a portion 15b and 16b, respectively, of, for example, A1 (or optionally also poly). The portions 15a, 15b and 16a, 16b, respectively, as shown in FIG. 1, may be connected together outside the part shown in the Figures. The doping concentration of acceptor atoms below the portions 15b, 16b can be increased by an extra p-type implantation in a known self-registering manner with respect to the poly strips 15a, 16a, so as to obtain a potential barrier for 2-phase operation. As shown in the Figure each pair 15a, 15b and each pair 16a, 16b corresponds in width with the width of a channel 1a and 1b, respectively (including the field oxide strips 2).
The clock electrodes 15a, 15b and 16b are connected to clock lines 17 and 18, respectively, for supplying the clock voltage φ s 1 and φ s 2 .
Two of the clock voltage electrodes of the parallel section are shown in the drawing, namely the electrodes 36 and 37, which are connected to the clock voltage sources φ p 9 and φ p 10 of the 10-phase clock system. The electrodes 36 and 37 comprise a poly strip 36a and 37a, respectively, forming the storage parts of the electrodes, and A1 (or poly) strips 36b and 37b, respectively, which define the transfer regions and are short-circuited outside the Figures to the parts 36a and 37a, respectively. In the same manner as in the series registers A, B, an extra p-type implantation (38) is carried out below the parts 36b, 37b so as to obtain a potential barrier and hence the desired direction in the charge transport. The first comb-shaped electrode 19 comprises a part 19a which is constructed in the lower most wiring layer, the polycrystalline silicon layer, and a part 19b which is present between said part 19a and the last clock electrode 37 and which is constructed in the A1-wiring layer and which is short-circuited to the part 19a. A p-type implantation is again provided below the electrode part 19b so as to obtain a potential barrier.
The second comb-shaped electrode 21 is constructed in the lowermost layer, the poly-wiring layer.
The teeth 20 of the comb 19 extend above the channels 1a, the teeth 22 of the comb 21 extend above the channels 1b of the parallel section. The control electrode 39 is present above the intermediate space between the teeth 20 of the comb 19 on the one hand and the comb 21 on the other hand; the control electrode 40 is provided above the intermediate space between the teeth 22 of the comb 21 on the one hand and the comb 19 on the other hand. As shown in FIGS. 2 to 4, a p-type implanted zone 38 may be provided in the said intermediate spaces so as to obtain the desired surface potential upon applying clock voltages of the same voltage values as the other clock voltages to be applied.
The transfer gate 23 also shown in FIG. 6 and constructed in the A1 wiring layer is present before the output register B. A p-type zone 38 is also provided below said transfer gate so as to obtain the desired surface potential.
In accordance with the invention, an extra electrode 41 is provided between the transfer gate 23 and the second comb-shaped electrode 21. This extra electrode is built up, in the same manner as the electrodes 36, 37, from two parts, one part 41a constructed in poly-Si which defines a storage site in the semiconductor body, and one part constructed in A1 which together with the underlying p-type implanted zone defines a transfer region. The electrode 41 forms buffer sites in which charge packets can be stored temporarily before being transferred to the series output register B which is not yet empty. As a result of this the influence of delays which might occur during this transport of charge packets between the teeth 22 and the series-out register B can be eliminated. For this purpose the width of the buffer electrode 41, or at least of the part 41a which defines the storage part in the semiconductor body, can be chosen to be much smaller than the length of the teeth 20, 22 and may be approximately the same (for example to within ±25%) as the length of the cross-bar of the second comb-shaped electrode. In a specific embodiment the width of strip 41a was approximately 5 μm, as well as the width of the strips 36 and 37 and the width of the cross-bar portions of the comb-shaped electrodes 19, 21. The length of the teeth of the comb 19, 21 in this embodiment was approximately 12 μm. According to the already mentioned equation τ=4L 2 . (π 2 D) -1 , according to which π is proportional to the square of L, this resulted in charge transfer times of approximately 20 n.sec. at L=5 μm, and of approximately 100 n.sec. at L approximately equal to 12 μm.
In order to explain the effect achieved by means of the invention, FIG. 5 shows a diagram of clock voltages with which the device is operated. It is assumed that the parallel section C is operated with a 10-phase ripple clock and that the clock voltage φ p 10 is applied to the last electrode of the parallel section situated before the comb electrode 19, 20. Of course, one of the other 10-phase clock voltages may be applied to the last electrode. The length of the parallel section is not relevant but may be a few hundred storage sites. The width of the parallel section is, for example, 256 channels so that the length of the series channels, which must be capable to comprise at least 128 charge packets, is also at least 256 storage sites. In FIG. 5, each time only seven pulses are shown of the series output register clocks φ s 1 and φ s 2 to read-out half a row, but it will be apparent that in order to read out half a row, 128 bits, 256 pulses are necessary. It is further assumed that the clock voltage levels vary between 0 and 5 Volts at a substrate voltage of, for example, -2.5 Volts. At these voltages a signal (packet of electrons) is transferred from a first electrode to a second electrode when at a voltage of 0 Volt at the first electrode the value of 5 V is applied to the second electrode (drop clocking). When the second electrode then returns to 0 V again, the electrons remain below the second electrode.
At the voltages shown in FIG. 5 the operation is as follows:
At t o a row of information comes below the last electrode in the parallel section connected to φ p 10 . At the instant t1 said row is transferred by the pulse φ k 1 below the first comb-shaped electrode 19. The charge packets are stored alternately below the teeth 20 and below the narrow parts of the electrode 19 between the teeth. As a result of the pulses φ c 1 and φ K 2 on the first control electrode 39 and the comb 21, the packets stored below the teeth 20 in the channels 1a are transferred to the second comb-shaped electrode 21 at t2. The packets which are stored in the channels 1b below the first comb-shaped electrode are not transferred due to the voltage 0 V at the second control electrode 40. At t3 the transferred 128 bits are further transported to the buffer electrode 41 by the pulse φ b . When the series-output register B is empty, said half row can be moved in the series output register B by applying the pulse φ 1g to the transfer gate 23 and simultaneously applying the voltage of 5 V to the electrodes 15a, 15b. By means of the clocks φ s 1 and φ s 3 the 128 bits (half a row) can be transported through the series-output register B to the output of the device, until at t7 all charge packets have been read out and the register B is empty again. Meantime the remaining half row, i.e. the charge packets below the first comb 19 in the channels 1b, can be further transported by the pulse φ K 2 on the second comb 21, 22 and the pulse φ c 2 on the second control electrode. These charge packets can be transferred directly to the buffer gate 41 by the pulse φ b (t6). As a result of the comparatively large length of the teeth 22 the time constant of said charge transport is large. Due to the presence of the buffer gate 41, this comparatively inert charge transport can take place in the time interval t6-t7 in which the first half row is still being read-out so that nevertheless no delays are introduced in the device with the inert charge transport. When the series register is empty (t7) the second half row of 128 bits can be moved below the electrodes 16 in the series-output register by the pulse φ TG . As a result of the small width of the electrode 40 this charge transport can occur very rapidly. The series-output register B is then filled again entirely and can be operated again in the usual manner. While these 128 bits are read-out again, the first half sub-row of a subsequent row of information, i.e. the bits of said row, can be transported below the teeth 20 and then to the narrow parts of the second comb between the teeth and from here to the buffer 40. This latter charge transport can occur rapidly so that now a short pulse on electrode 40 might suffice (t8). In this example, however, the pulse φ b at t8 has been chosen to be as long as the pulse φ b at t7 so as to simplify the clock control.
It will be apparent that the invention is not restricted to the example described, but that many variations are possible to those skilled in the art without departing from the scope of this invention. For example, in the embodiment described the sequence of the sub-rows may be reversed, so that from a whole row of information first the charge packets in the channels 1b and then the charge packets in the channels 1a are transferred to the output register B.
Furthermore, the invention may be used in matrixlike structures other than SPS-memories, for example in image sensors. | A series-parallel-series memory or other parallel-to-series CCD has charge-signals interlaced in alternate parallel channels 1a and 1b, and de-interlacing electrodes (19, 20, 21, 22) at the parallel-to-series transition. In order to avoid delay effects as a result of comb-shaped electrode configurations of the de-interlacing electrodes, and associated complex clock control, a narrow extra electrode (41) is provided between the de-interlacing electrodes and the series-output register (B). This electrode (41) may serve as a buffer electrode for each half row of information (from 1a or 1b) while the preceding half row (from 1b or 1a) is transported through the series output register. | 7 |
[0001] This application claims priority to U.S. provisional patent application Ser. No. 61/058,908 filed Jun. 4, 2008, entitled “Remote Hydraulic Shifting Apparatus, Systems and Methods”, which is hereby incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The present disclosure relates generally to downhole valves and other devices that are movable between positions and, more particularly, to selectively remotely shifting such valves or other devices.
BACKGROUND OF THE INVENTION
[0003] In hydrocarbon recovery operations in subterranean wells, it is often desirable to selectively shift a valve or other device between positions. For example, there are instances when it is necessary or desirable to selectively close a downhole device to isolate the well, such as to remove, repair or replace equipment. Likewise, there are occasions when it is necessary to shift open the downhole device, such as to allow the recovery of produced fluids.
[0004] In many applications, it may be particularly useful to be able to selectively remotely shift a valve or other device between positions on multiple occasions. For example, in hydrocarbon producing wells having a generally low bottom-hole pressure, an electric submersible pump is often inserted into the well to assist in drawing produced fluids up into the production tubing. However, these pumps typically have a limited useful life-span as compared to the producing life of the well, so operations must be interrupted to replace the pump. In such instances, it is often desirable to isolate the well below the pump by closing one or more valves during removal and replacement of the pump, and thereafter to re-open the valve(s) and continue production.
[0005] Some present techniques for selectively shifting downhole devices require the insertion into the well of a shifting tool carried on pipe, coiled tubing or the like to mechanically shift the valve between positions. This process, which often requires the use of a rig or other equipment, may be time consuming and costly.
[0006] It should be understood that the above-described discussion is provided for illustrative purposes only and is not intended to limit the scope or subject matter of the appended claims or those of any related patent application or patent. Thus, none of the appended claims or claims of any related patent application or patent should be limited by the above discussion or required to address, include or exclude all or any of the above-cited examples, features and/or disadvantages merely because of their mention above.
[0007] Accordingly, there exists a need for improved systems, apparatus and methods capable of shifting a valve or other device disposed in a subterranean well and having one or more of the attributes, capabilities or features described below or in the subsequent sections of this disclosure, or shown in the appended drawings: may be remotely actuated from the surface with hydraulic pressure; may be remotely actuated from the surface with pneumatic pressure; may be remotely actuated from the surface by electric power; may be capable of both opening and closing the shiftable device multiple times as desired; may be capable of selectively repeatedly shifting the shiftable device between at least two positions; may be connected to a production tubing and releasably engageable with the shiftable device; is not part of the lower completion assembly or components; may be disengaged from the shiftable device, removed from the well, reinserted into the well and re-engaged with the device multiple times; may be capable of shifting the shiftable device without requiring the insertion or manipulation of pipe or coiled tubing in the well, or the use of a rig, wet connect or slick line; allows well zone isolation for quickly replacing, adding, removing or servicing equipment or other operations; does not require the engagement of control lines to the shiftable device; may be useful to quickly open and close off the well at will and repeatedly; is easily engageable and disengageable with the shiftable device; is slideably engageable with the shiftable device; allows the well to be sealed before starting operations; or a combination thereof.
BRIEF SUMMARY OF THE DISCLOSURE
[0008] In some embodiments, the present disclosure involves methods of shifting a shiftable device between at least first and second positions with a removable actuator. The shiftable device is anchored within a subterranean well. The actuator is inserted into the well and releasably engaged with the shiftable device. When the shiftable device is in a first position, the actuator may be actuated by providing at least one among hydraulic pressure, pneumatic pressure and electric power thereto to shift the shiftable device into a second position without requiring the use of either a rig or a slick line. The actuator may be disengaged from the shiftable device.
[0009] In various embodiments, the present disclosure involves methods of shifting a shiftable device between at least first and second positions with an actuator. The shiftable device is anchored within a subterranean well. These embodiments include coupling the actuator to a production tubing. After the shiftable member is anchored in the well, the production tubing is inserted into the well and the actuator is slideably engaged with the shiftable device. Whenever and as many times as desired, the actuator may be actuated by providing at least one among hydraulic pressure, pneumatic pressure and electric power to the actuator to shift the shiftable device between positions without requiring the use of either a rig or a slick line.
[0010] There are embodiments of the present disclosure that involve a method of remotely shifting a downhole valve between open and closed positions with a hydraulic valve actuator. These embodiments include inserting the valve actuator into the well and engaging the valve actuator with the valve (in a closed position). Thereafter and whenever the valve is in a closed position, the valve actuator may be hydraulically actuated to shift the valve into an open position. Likewise, when the valve is in an open position, the valve actuator may be hydraulically actuated to shift the valve into a closed position.
[0011] In accordance with the present disclosure, some embodiments involve an apparatus useful for shifting a shiftable device between at least first and second positions. The shiftable device is anchored in a subterranean well. The apparatus includes a housing insertable into and out of the well without disturbing the location of the shiftable device within the well. A hydraulically-driven piston is disposed within the housing. At least two hydraulic control lines are fluidly coupled to the housing and capable of providing hydraulic pressure from the surface to the housing to cause the piston to move up and down within the housing. An engagement arm extends from the piston and is releasably engageable with the shiftable device. The engagement arm moves up and down with the piston and is capable of mechanically shifting the shiftable device between at least first and second positions without requiring the use of either a rig or a slick line. The piston and engagement arm may thus be hydraulically-actuated to selectively remotely shift the shiftable member between positions.
[0012] Accordingly, the present disclosure includes features and advantages which are believed to enable it to advance downhole device shifting technology. Characteristics and potential advantages of the present disclosure described above and additional potential features and benefits will be readily apparent to those skilled in the art upon consideration of the following detailed description of various embodiments and referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The following figures are part of the present specification, included to demonstrate certain aspects of various embodiments of this disclosure and referenced in the detailed description herein:
[0014] FIG. 1 is a partial schematic and partial cross-sectional view of an embodiment of a valve actuator useful for shifting an example valve disposed in a subterranean well in accordance with an embodiment of the present disclosure;
[0015] FIG. 2 is a cross-sectional view of a portion of an example shifter of an embodiment of a valve actuator in accordance with the present disclosure;
[0016] FIG. 3A is a partial cross-sectional view of a portion of the valve actuator of FIG. 1 shown with the example valve in a closed position;
[0017] FIG. 3B is a partial cross-sectional view of a portion of the valve actuator of FIG. 1 shown with the example valve in an open position;
[0018] FIG. 3C is a partial cross-sectional view of a portion of the valve actuator of FIG. 1 shown with the example valve in a closed position;
[0019] FIG. 3D is a partial cross-sectional view of a portion of the valve actuator of FIG. 1 shown releasing from the exemplary valve in a closed position;
[0020] FIG. 4A is a partial schematic and partial cross-sectional view of another embodiment of a valve actuator useful for shifting an example sleeve disposed in a subterranean well in accordance with an embodiment of the present disclosure;
[0021] FIG. 4B a partial schematic and partial cross-sectional view of the exemplary valve actuator of FIG. 4A shown shifting the illustrated sleeve into a closed position;
[0022] FIG. 5A is a partial perspective and partial cross-sectional view of a portion of another embodiment of a valve actuator having an exemplary engagement arm shifting an example sliding sleeve into an open position in accordance with the present invention;
[0023] FIG. 5B shows the exemplary valve actuator of FIG. 5A after having shifted the illustrated sliding sleeve into an open position.
[0024] FIG. 5C shows the exemplary engagement arm of FIG. 5A shifting the illustrated sliding sleeve into a closed position; and
[0025] FIG. 5D shows the exemplary valve actuator of FIG. 5A after having shifted the illustrated sliding sleeve into a closed position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0026] Characteristics and advantages of the present disclosure and additional features and benefits will be readily apparent to those skilled in the art upon consideration of the following detailed description of exemplary embodiments of the present disclosure and referring to the accompanying figures. It should be understood that the description herein and appended drawings, being of example embodiments, are not intended to limit the appended claims or claims of any patent or patent application claiming priority hereto. On the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the claims. Many changes may be made to the particular embodiments and details disclosed herein without departing from such spirit and scope.
[0027] In showing and describing preferred embodiments, common or similar elements are referenced in the appended figures with like or identical reference numerals or are apparent from the figures and/or the description herein. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness.
[0028] As used herein and throughout various portions (and headings) of this patent application, the terms “invention”, “present invention” and variations thereof are not intended to mean every possible embodiment encompassed by this disclosure or any particular claim(s). Thus, the subject matter of each such reference should not be considered as necessary for, or part of, every embodiment hereof or of any particular claim(s) merely because of such reference. The terms “coupled”, “connected”, “engaged” and the like, and variations thereof, as used herein and in the appended claims are intended to mean either an indirect or direct connection or engagement. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices and connections. Also, the terms “upward” and “downward” as used herein and in the appended claims may be relative to the top and/or bottom of a component, assembly or space and are not necessarily limited to movement in a vertical axis or plane.
[0029] Certain terms are used herein and in the appended claims to refer to particular components. As one skilled in the art will appreciate, different persons may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. Also, the terms “including” and “comprising” are used herein and in the appended claims in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Further, reference herein and in the appended claims to components and aspects in a singular tense does not necessarily limit the present disclosure or appended claims to only one such component or aspect, but should be interpreted generally to mean one or more, as may be suitable and desirable in each particular instance.
[0030] Referring initially to FIG. 1 , an embodiment of a valve actuator 10 useful for shifting a valve 14 or other device disposed in a subterranean well 12 is shown. The illustrated well 12 is vertically oriented, but could instead be horizontal, deviated or have any other orientation. In this embodiment, the valve 14 is a mechanical isolation ball valve 16 , which may be shifted between open and closed positions, as desired, with the valve actuator 10 . The illustrated ball valve 16 is contained within a valve assembly 18 , which is connected within a lower completion arrangement 22 coupled to a casing 24 , such as with a seal/locator assembly 28 and packer 30 . For example, the lower completion arrangement 22 may be run into and set in the well 12 in one trip with the valve 14 in a closed position before the valve actuator 10 is introduced into the well 12 . However, this set of components, configuration and sequence are provided for illustrative purposes only and are not required for, or limiting upon, the present disclosure.
[0031] It should be understood that the valve actuator 10 may be used to move any type or configuration of valve 14 or other device between any desired positions. Some examples of such valves and other devices are flapper valves, ball valves, mechanical or hydraulic sliding sleeves, gravel pack closing sleeves and other fluid loss or recovery devices. Thus, the present invention is not limited to use with any particular type of valve or other shiftable device. As used herein and in the appended claims, unless specified otherwise, the term “valve” includes any type of device that is moveable between at least two positions. Further, the present invention is not limited by the number or nature of positions between which the valve may be shifted. Additionally, the valve may be disposed at any desired location in a subterranean well and in any desired downhole arrangement of components. Accordingly, the present disclosure is not limited by the type, configuration, action, purpose or operation of the device(s) that may be shifted in accordance with this disclosure.
[0032] Still referring to FIG. 1 , the valve actuator 10 may have any desired form, configuration and operation. In this embodiment, the valve actuator 10 includes a shifter 32 which effectively moves the valve 14 between positions. In some embodiments, referring to FIG. 2 , the shifter 32 may include at least one balanced piston 34 and at least one engagement arm 38 extending therefrom and moveable therewith. The exemplary piston 34 is disposed and reciprocable within a housing 42 by surface-controlled hydraulic (or pneumatic) pressurization through control lines 46 , 48 . In other embodiments, the piston 34 may be electrically-actuated. For example, one or more electric power line (not shown) may extend from the surface to an electric motor (not shown) connected with and used for powering the piston 34 .
[0033] Still referring to FIG. 2 , the illustrated piston 34 is shown in a “down” position after hydraulic fluid pressurization in the housing 42 via the control line 46 . If it is desired to move the exemplary piston 34 (and engagement arm 38 ) to an “up” position (not shown), sufficient hydraulic fluid pressurization is provided via the control line 48 . Thus, the piston 34 and engagement arm 38 of this embodiment are selectively, remotely moveable via hydraulics (or pneumatics) between “up” and “down” positions. However, the valve actuator 10 of the present disclosure is not limited to this configuration. For example, a different arrangement and number of control lines may be used. For other examples, the piston 34 (and engagement arm 38 ) may be moveable between more than two positions or actuated in a different manner (other than hydraulics or pneumatics; e.g. electrical power). Further, the piston 34 and engagement arm 38 may be separate components coupled together, integrally formed or part of or contained within other components. Also, in many embodiments, the shifter 32 may include different or additional components. Thus, the present invention is not limited by the type, configuration and operation of the shifter 32 or other embodiments of the valve actuator 10 .
[0034] Referring back to FIG. 1 , the valve actuator 10 may be associated with the valve assembly 18 in any suitable manner and with any desired components to cause the valve 14 to move between positions. In this embodiment, for example, the engagement arm 38 is slideable into and out of the upper end of the valve assembly 18 . The exemplary arm 38 includes at least one profile, or rib, 52 that is engageable with upper and lower collets, or ribs, 56 , 58 disposed on an internal sleeve 60 in the valve assembly 18 . As the engagement arm 38 moves up or down (such as, e.g., by action of the piston 34 of FIG. 2 ), the profile 52 engages and pushes one of the collets 56 , 58 to move the valve 16 between positions.
[0035] In FIG. 3A , for example, the engagement arm 38 is engaged with the valve assembly 18 and the ball valve 16 is in a closed position. This position of the engagement arm 38 is between “up” and “down” positions. As the piston (not shown) is actuated to move from an “up” to a “down” position, it causes the exemplary engagement arm 38 to move down (left to right in FIGS. 3A-D ). The downward movement of the arm 38 causes the profile 52 to abut the lower collet 58 and push it and the internal sleeve 60 downwardly. FIG. 3A thus illustrates the position of the exemplary profile 52 as it engages the lower collet 58 to begin opening the valve 14 .
[0036] Continued downward movement of the exemplary arm 38 and internal sleeve 60 will cause the ball valve 16 to be shifted from a closed position to an open position, as shown in FIG. 3B . In this example, with sufficient downward movement to open the valve 16 , the lower collet 58 will seat in a lower undercut 66 in the valve assembly 18 , allowing the profile 52 to move down past the lower collet 58 ( FIG. 3B ), such as, for example, to accommodate any overstroke of the piston (not shown).
[0037] In this embodiment, the reverse movement of the piston (not shown) and engagement arm 38 with cause the profile 52 to engage the upper collet 56 and drive the internal sleeve 60 in the upward direction to move the valve 14 from an open to a closed position. Referring to FIG. 3B , for example, when the illustrated ball valve 16 is in an open position, the upward movement of the engagement arm 38 will cause the profile 52 to pass by the lower collet 58 (if the profile 52 previously bypassed it) and abut the upper collet 56 ( FIG. 3C ), pushing it and the internal sleeve 60 upwardly. This movement will shift the ball valve 16 into a closed position. As shown in FIGS. 3C and 3D , in this example, continued upward movement of the engagement arm 38 will cause the upper collet 56 to seat in an upper undercut 64 in the valve assembly 18 and the illustrated profile 52 to pass over the upper collet 56 . The engagement arm 58 and, thus, the shifter 32 may thereafter be slideably disengaged from the valve assembly 18 , allowing the exemplary valve actuator 10 (e.g. FIG. 1 ) to be entirely removable from the well 12 without disturbing the location of the valve 14 therein. However, the present disclosure is not limited to this particular operation or arrangement of components.
[0038] If desired, the valve actuator 10 may be removed from the well 12 , replaced back into the well 12 and again used for shifting the valve 14 . This procedure may be repeated as many times as desired, such as for equipment service or replacement, to isolate the well for conducting other downhole operations, or any other desired purpose. Referring back to FIG. 1 , for example, the exemplary valve actuator 10 is coupled to the lower end of a production tubing 74 , which also carries an electric submersible pump 70 . The pump 70 is useful to assist in drawing produced oil and/or gas up into the production tubing 74 , such as in a low bottom-hole pressure well, as is and becomes further known. In this arrangement, if it becomes necessary to replace or service the pump 70 (production tubing 74 , valve actuator 10 , etc.), it may be desirable to close the valve 14 , isolate the well 12 and remove the tubing 74 and associated components from the well 12 . Accordingly, after the exemplary valve actuator 10 is actuated to shift the valve 14 to a closed position, the production tubing 74 (with submersible pump 70 and valve actuator 10 ) may be retrieved up and out of the well 12 . After the pump 70 (or other equipment) is serviced or replaced, the tubing 74 and connected components may be returned into the well 12 .
[0039] Still referring to FIG. 1 , if desired, one or more re-entry guide 78 may be associated with the valve actuator 10 , tubing 74 or other component to assist in alignment and reinsertion of the tubing 74 and valve actuator 10 . Also, in the illustrated example, as shown in FIG. 3D , the valve assembly 18 includes a guide 82 to assist in aligning the engagement arm 38 within the valve assembly 18 . After the arm 38 is slideably engaged with the valve assembly 18 , downward movement of the illustrated arm 38 will cause the exemplary profile 52 to bypass the upper collet 56 and eventually engage the lower collet 58 to shift the valve 16 from a closed to an open position, such as described above. The valve actuator 10 may thereafter be used as needed to shift the exemplary valve 16 between open and closed positions, and the entire process may be repeated as desired.
[0040] In FIG. 4A , another embodiment of the valve actuator 10 is shown in a multi-flow production configuration. In this example, the valve actuator 10 is useful to open and close a mechanical closing sleeve 86 . The illustrated valve actuator 10 is disposed at the end of the production tubing 74 and includes a shifter 32 having a piston (not shown) disposed in a housing 42 and operable such as described above with respect to FIGS. 1 & 2 . In this example, the piston drives a perforated inner pipe 88 upon which the engagement arm 38 is disposed. The illustrated engagement arm 38 is a support mandrel for at least one engager 90 that is engageable with the sleeve 86 . The engager 90 may be a collet, retractable finger or any other suitable component or member.
[0041] Still referring to FIG. 4A , the illustrated closing sleeve 86 opens and closes at least one port 87 formed in the lower completion arrangement 22 , or otherwise provided in the well 12 below a packer 30 . The port 87 allows fluid flow from an annulus 92 into the perforated pipe 88 during production, such as shown with flow arrows 94 . The lower completion arrangement 22 , shown mounted in the well 12 , includes a check, or standing, valve 96 that is liftable off a seat 98 by upward fluid pressure to allow fluid flow through the pipe bore 100 in a lower pipe section 102 of the arrangement 22 . The illustrated lower pipe section 102 is perforated, so that upwardly flowing fluid may pass both through the bore 100 (e.g. flow arrows 104 ) and into the annulus 92 (e.g. flow arrows 106 ). Accordingly, FIG. 4A illustrates the “down” position of the exemplary engagement arm 38 and the open positions of the closing sleeve 86 and check valve 96 during production.
[0042] If production ceases or it is desirable to isolate or seal off the well 12 at this interval, such as to replace the submersible pump 70 or other hardware, or for other operations, the piston (not shown) of the shifter 32 may be actuated from surface to move the perforated pipe 88 and engagement arm 38 upwardly. Referring to FIG. 4B , sufficient upward movement of the illustrated engagement arm 38 causes the engager(s) 90 to engage and close the sleeve 86 . In this embodiment, continued upward movement of the engagement arm 38 will allow the engager(s) 90 to collapse or otherwise bypass or move above the sleeve 86 , allowing removal of the production tubing 74 and all attached equipment (the valve actuator 10 , perforated inner pipe 88 , submersible pump 70 , etc.) from the well 12 . Later, the production tubing 74 and other components may be reinserted into the well and the valve actuator 10 used to re-open the sleeve 86 generally similarly as described above with respect to other embodiments.
[0043] In FIGS. 5A-D , another embodiment of an engagement arm 38 in accordance with the present disclosure is shown useful for opening and closing a sliding sleeve 110 . The illustrated sliding sleeve 110 includes and at least one passageway 112 alignable with at least one port 114 formed in a pipe 116 (or other component), such as to allow fluid flow into or out of a bore 117 . The sleeve 110 also includes a B-shifting profile arrangement with upper and lower profiles 124 , 126 .
[0044] The illustrated engagement arm 38 includes a multi-action, collapsible, B-shifting body portion 106 with collets 118 , 120 . The upper collet 118 is releasably engageable with the lower profile 126 of the sleeve 110 and the lower collet 120 is releasably engageable with the upper profile 124 . The illustrated arm 38 is driven by a piston (not shown) as part of a shifter 32 and operates generally similarly as previously described with respect to other embodiments.
[0045] In FIG. 5A , the exemplary engagement arm 38 is shown shifting the sleeve 110 into an open-port position. As the arm 38 is moved downwardly (from left to right in FIGS. 5A-D ), the upper collet 118 engages the lower profile 126 to move the sleeve 110 , aligning the passageway 112 with the port 114 , as shown in FIG. 5B . If desired, continued downward movement of the arm 38 may cause the body 106 of the arm 38 to collapse, if necessary, to allow the upper collet 118 to disengage from and bypass the lower profile 126 .
[0046] Referring now to FIGS. 5C-D , the exemplary engagement arm 38 is shown shifting the sleeve 110 into a closed-port position. As the arm 38 is moved upwardly, the lower collet 120 will engage the upper profile 124 and move the sleeve 110 upwardly until the passageway 112 and port 114 are misaligned and out of fluid communication. If desired, continued upward movement of the arm 38 will cause the body 106 to collapse, if necessary, to allow the lower collet 120 to disengage from and bypass the upper profile 124 and the arm 38 to disengage completely from the sleeve 110 and pipe 116 , if desired.
[0047] Preferred embodiments of the present disclosure thus offer advantages over the prior art and are well adapted to carry out one or more of the objects of this disclosure. However, the present invention does not require each of the components and acts described above and is in no way limited to the above-described embodiments, methods of operation. Any one or more of the above components, features and processes may be employed in any suitable configuration without inclusion of other such components, features and processes. Moreover, the present invention includes additional features, capabilities, functions, methods, uses and applications that have not been specifically addressed herein but are, or will become, apparent from the description herein, the appended drawings and claims.
[0048] The methods that are provided in or apparent from the description above or claimed herein, and any other methods which may fall within the scope of the appended claims, may be performed in any desired suitable order and are not necessarily limited to any sequence described herein or as may be listed in the appended claims. Further, the methods of the present invention do not necessarily require use of the particular embodiments shown and described herein, but are equally applicable with any other suitable structure, form and configuration of components.
[0049] While exemplary embodiments of the invention have been shown and described, many variations, modifications and/or changes of the system, apparatus and methods of the present invention, such as in the components, details of construction and operation, arrangement of parts and/or methods of use, are possible, contemplated by the patent applicant(s), within the scope of the appended claims, and may be made and used by one of ordinary skill in the art without departing from the spirit or teachings of the invention and scope of appended claims. Thus, all matter herein set forth or shown in the accompanying drawings should be interpreted as illustrative, and the scope of the disclosure and the appended claims should not be limited to the embodiments described and shown herein. | In some embodiments a method of shifting a downhole-located device between positions with an actuator includes inserting the actuator into the well, engaging the actuator with the shiftable device and actuating the actuator to shift the shiftable device between positions. | 4 |
FIELD OF THE INVENTION
[0001] The invention relates generally to a gear coupling, and more specifically to an oil lubricated gear coupling.
BACKGROUND OF THE INVENTION
[0002] Couplings are used to transmit torque and rotational movement between two machines, where the input and output shafts are misaligned axially, radially, angularly, or a combination of the aforementioned. Different types of couplings have different characteristics and are used in different applications.
[0003] Gear couplings have high torque, high misalignment, and moderate speed capability with high torsional stiffness. Gear couplings are usually lubricated by grease, which tends to remain in a cylindrical shape around the outside of the sleeve gear away from the sealing devices. Grease lubricated gear couplings with low misalignment may use contact seals outboard of the gear teeth, while high misalignment couplings may have lips on the end plates extending under the hub gear teeth. However, it is sometimes advantageous to use a lubricant that has low viscosity such as oil where it is difficult or expensive to dismantle the associated machines, to enable the lubricant to be replaced by draining and refilling the coupling using suitable plugs. However, the use of a low viscous lubricant creates sealing problems, in particular, where the couplings are subject to frequent starting and stopping applications.
[0004] One embodiment of a lubricated gear coupling is disclosed in U.S. Pat. No. 6,171,197 (Boucquey) which discloses a coupling that allows angular and radial misalignment as well as axial displacement between two shafts. The coupling comprises two hubs, a sleeve tube, stop means to prevent excessive displacement, and sealing rings. Boucquey fails to disclose or teach, however, a lubricated gear coupling with plugs that can be removed and replaced in order to drain and fill lubricant. Boucquey also fails to disclose a channel between sealing rings which aids in preventing any contaminant from entering the chamber containing the lubricant. Instead, Boucquey teaches a lubricated gear coupling with a sealing ring that experiences negligible radial displacement when misalignment occurs and is the sole means for preventing any contamination of the lubricant.
[0005] Another embodiment of a lubricated gear coupling is disclosed in U.S. Pat. No. 6,524,191 (Tennies) which discloses an inverted coupling for transmitting power between the shafts of an electric motor and a gear box pinion. The coupling has a shaft hub mounted on the motor shaft, a gearbox hub mounted on the gearbox shaft, annular splines, sleeve ring gears, and a coupling member sleeve seal. Tennies fails to disclose or teach, however, a separate contaminant excluding seal in addition to the lubricant retaining seal. Tennies also fails to disclose a channel between sealing rings which aids in preventing any contaminant from entering the chamber containing the lubricant.
[0006] Yet another embodiment of a lubricated gear coupling is disclosed in United States Application Publication No. 2011/0012314 (Nakamura) which discloses an apparatus having a first member, a second member, a first sealing body, and a second sealing body. The lubricant is sealed between the first member and the second member by the first sealing body. The second sealing body is disposed adjacent to the first sealing body opposite the lubricant and slides from a reserve position to a sealing position in the event that the first sealing body is compromised. Each sealing body includes an oil seal and a dust seal. Nakamura fails to disclose or teach, however, a lubricated gear coupling that has individual seals for retaining lubricant and excluding contaminant. Additionally, Nakamura fails to disclose plugs that can be removed and replaced in order to drain and fill the lubricant. Instead, Nakamura teaches a sealing body that has the second sealing body in a reserve position and only functions as a seal when moved into a sealing position after the first sealing body has become compromised.
[0007] Thus, there exists a long felt need for a lubricated gear coupling that contains two separate seals for retaining lubricant and excluding contaminant from the lubricant, a means for easily draining the lubricant without completely dismantling the gear coupling, and having features within the gear coupling to minimize the amount of lubricant that migrates towards the lubricant seal.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention broadly includes a lubricated gear coupling for transmitting torque between an input shaft and an output shaft, comprising a first hub connected to the input shaft, the first hub comprising at least one gear tooth and a first raised edge, a second hub non-rotatably connected to the output shaft, the second hub comprising at least one gear tooth and a second raised edge, a sleeve gear comprising at least one gear tooth, wherein the first hub and the second hub are arranged within the sleeve gear, the gear tooth of the first hub and second hub corresponding with the gear tooth of the sleeve gear, wherein torque is transmitted from the input shaft to the output shaft with axial, radial, and angular movement occurring between the first hub and second hub, and a draining means arranged on the sleeve gear, wherein the lubricant can flow through.
[0009] The invention also comprises a first, second, third, and fourth seal, wherein the first seal and the second seal are operatively arranged between the first hub and the sleeve gear, the first seal preventing discharge of the lubricant, the second seal preventing contamination of the lubricant. The third seal and the fourth seal are operatively arranged between the second hub and the sleeve gear, the third seal preventing discharge of the lubricant, and the fourth seal preventing contamination of the lubricant.
[0010] A general object of the invention is to provide a lubricated gear coupling which performs the same function as prior gear couplings but minimizes the contamination or discharge of the lubricant.
[0011] A further object of the invention is to provide a cost savings for the maintenance and lubricant replacement of a lubricated gear coupling.
[0012] These and other objects, features and advantages of the present invention will become readily apparent upon a reading and review of the following detailed description of the invention, in view of the appended drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The nature and mode of operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying figures, in which:
[0014] FIG. 1 is a perspective view of the gear coupling of the present invention;
[0015] FIG. 2 is a front view of the gear coupling;
[0016] FIG. 3 is a back view of the gear coupling;
[0017] FIG. 4 is a side view of the gear coupling;
[0018] FIG. 5 is a perspective view of input hub 12 and output hub 22 ;
[0019] FIG. 6 is a perspective view of the gear coupling with second end plate 50 b removed; and,
[0020] FIG. 7 is a cross sectional view of the gear coupling, taken generally along line 7 - 7 in FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0021] At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the invention. It is to be understood that the invention as claimed is not limited to the disclosed aspects.
[0022] Furthermore, it is understood that this invention is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present invention as claimed.
[0023] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention pertains. It should be understood that any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention.
[0024] Adverting now to the figures, FIG. 1 is a perspective view of gear coupling 10 which broadly comprises input hub 12 (shown in FIG. 2 ), output hub 22 , first sleeve gear 30 , second sleeve gear 36 , first end plate 50 a , second end plate 50 b , bolts 60 , nuts 62 , drain plugs 65 a (shown in FIG. 4 ), and drain plugs 65 b . Input hub 12 and output hub 22 are arranged within first sleeve gear 30 and second sleeve gear 36 , respectively. First sleeve gear 30 and second sleeve gear 36 are secured to one another by bolts 60 and nuts 62 which are operatively arranged on flange 31 of first sleeve gear 30 and flange 37 of second sleeve gear 36 . First end plate 50 a is secured to first sleeve gear 30 by retaining screws 51 a . Additionally, second end plate 50 b is secured to second sleeve gear 36 by retaining screws 51 b . Lubricant 72 (shown in FIG. 7 ) is enclosed within first sleeve gear 30 and second sleeve gear 36 which reduces friction between input hub 12 and first sleeve gear 30 and between output hub 22 and second sleeve gear 36 while in operation (shown in FIG. 7 ). Drain plugs 65 a (shown in FIG. 4 ) are operatively arranged on exterior surface 33 of first sleeve gear 30 to allow for the removal and replacement of lubricant 72 within first sleeve gear 30 . Additionally, drain plugs 65 b are operatively arranged on exterior surface 39 of second sleeve gear 36 to allow for the removal and replacement of lubricant 72 within second sleeve gear 36 . This allows a user to perform regular maintenance on gear coupling 10 without completely dismantling gear coupling 10 . In a preferred embodiment, drain plugs 65 a and 65 b are screws which engage and secure with threaded inserts on exterior surfaces 33 and 39 of first sleeve gear 30 and second sleeve gear 36 . It should be appreciated, however, that the use of different types of removable plugs is possible and considered to be within the scope of the invention as claimed.
[0025] FIG. 2 and FIG. 3 are a front and back view of gear coupling 10 , respectively. As shown in the figures, retaining plate 42 is concentrically arranged within input hub 12 . Retaining plate fastener 44 and pins 45 are operatively arranged on retaining plate 42 , which would engage an input means such as a shaft (not shown) to rotate gear coupling 10 . An input means (not shown) would also engage sleeve 40 , which is concentrically arranged within input hub 12 , in order to limit the torque applied to gear coupling 10 . In a preferred embodiment, retaining screws 51 a and 51 b are arranged symmetrically on the face of first end plate 50 a and second end plate 50 b , respectively. Additionally, screws 60 and nuts 62 are symmetrically arranged on flanges 31 and 37 of first sleeve gear 30 and second sleeve gear 36 . It should be appreciated, however, that different asymmetrical arrangements are possible and considered to be within the scope of the invention as claimed.
[0026] FIG. 4 is a side view of gear coupling 10 . As shown in the figure, input hub 12 is co-linear with output hub 22 and first sleeve gear 30 is co-linear with second sleeve gear 36 . Input hub 12 , output hub 22 , first sleeve gear 30 , and second sleeve gear 36 all rotate about axis 80 while gear coupling 10 is in operation and no misalignment occurs. It is important to note that input hub 12 and output hub 22 can be misaligned axially, radially, and angularly. Also shown in the figure is the symmetrical arrangement of drain plugs 65 a on exterior surface 33 of first sleeve gear 30 and the symmetrical arrangement of drain plugs 65 b on exterior surface 39 of second sleeve gear 36 .
[0027] FIG. 5 is a perspective view of input hub 12 and output hub 22 . Input hub 12 comprises gear teeth 14 , first surface 16 , second surface 18 , and sleeve 40 . Output hub 22 comprises gear teeth 24 , first surface 26 , and second surface 28 (shown in FIG. 7 ). In a preferred embodiment, input hub 12 and output hub 22 are manufactured from a high strength material such as steel. It should be appreciated, however, that the use of different materials is possible and considered to be within the scope of the invention as claimed. For example, input hub 12 and output hub 22 could be manufactured from a composite material if the operating environment is corrosive to steel or a ductile iron if stresses are within an acceptable range. Additionally, gear teeth 14 and gear teeth 24 comprise a spherical crown at the outer most edge of each gear tooth and an axially tapered flank to permit angular misalignment.
[0028] FIG. 6 is a perspective view of gear coupling 10 with second end plate 50 b removed from second sleeve gear 36 . As shown in the figure, gear teeth 38 are concentrically arranged within sleeve gear 36 . Output hub 22 is substantially non-rotatable with respect to second sleeve gear 36 via gear teeth 38 engaging with gear teeth 24 of output hub 22 (shown in FIG. 7 ). Gear teeth 38 and gear teeth 24 are designed to allow for axial, radial, or angular misalignment of input hub 12 and output hub 22 . Additionally, gear teeth 14 of input hub 12 and gear teeth 32 of first sleeve gear 30 are designed to allow for axial, radial, or angular misalignment of input hub 12 and output hub 22 . In order to ensure that output hub 22 stays engaged with sleeve gear 36 via gear teeth 24 and gear teeth 38 while misalignment occurs, bump stops 58 c and 58 d are concentrically arranged within second sleeve gear 36 at the sides of gear teeth 38 . As misalignment between input hub 12 and output hub 22 occurs while gear coupling 10 is in operation, output hub 22 slides axially, radially, and angularly within second sleeve gear 36 along gear teeth 38 and gear teeth 24 to ensure that there is no excessive torque or stress on gear coupling 10 . Additionally, input hub 12 slides axially, radially, and angularly within first sleeve gear 30 along gear teeth 32 and gear teeth 14 due to misalignment of input hub 12 and output hub 22 while gear coupling 10 is in operation (shown in FIG. 7 ). To ensure that gear teeth 14 of input hub 12 stay engaged with gear teeth 32 of first sleeve gear 30 , bump stops 58 a and 58 b are concentrically arranged within first sleeve gear 30 at the sides of gear teeth 32 (shown in FIG. 7 ). In a preferred embodiment, gear teeth 12 , 24 , 32 , and 38 are substantially similar to spur gears which allow axial, angular, and radial displacement of input hub 12 and output hub 22 while having input hub 12 engaged with first sleeve gear 30 and output hub 22 engaged with second sleeve gear 36 . It should be appreciated, however, that the use of different gear configurations is possible and considered to be within the scope of the invention as claimed. For example, a planetary gear could be used to transmit torque from input hub 12 to first sleeve gear 30 but a spur gear can be used to transmit torque from second sleeve gear 36 to output hub 22 .
[0029] FIG. 7 is a cross section of gear coupling 10 taken generally along line 7 - 7 in FIG. 2 . As shown in the figure, first end plate 50 a comprises extension 52 , surface 52 a , and surface 52 b and second end plate 50 b comprises extension 53 , surface 53 a , and surface 53 b . Retaining seal 54 a is arranged between extension 52 and input hub 12 along surface 52 b of extension 52 and surface 18 of input hub 12 . Additionally, retaining seal 54 b is arranged between extension 53 and output hub 22 along surface 52 b of extension 52 and surface 18 of input hub 12 . Lubricant 72 is arranged between gear teeth 14 of input hub 12 and gear teeth 32 of first sleeve gear 30 as well as between gear teeth 24 of output hub 22 and gear teeth 38 of second sleeve gear 36 to reduce friction during misalignment. Input hub 12 and output hub 22 have raised edges 74 a and 74 b , respectively, to mitigate lubricant 72 from approaching retaining seals 54 a and 54 b while gear coupling 10 is in operation. To prevent contamination of lubricant 72 , excluding seal 56 a is arranged between extension 52 and input hub 12 along surface 52 a of extension 52 and surface 16 of input hub 12 . Additionally, excluding seal 56 b is arranged between extension 53 and output hub 22 along surface 53 a of extension 53 and surface 26 of output hub 22 . In a preferred embodiment, retaining seals 54 a and 54 b and excluding seals 56 a and 56 b are rubber lip seals. It should be appreciated, however, that the use of different materials for the seals is possible and considered to be within the scope of the invention as claimed. Channel 75 a is formed between input hub 12 and extension 52 and allows for axial, radial, and angular movement of input hub 12 with relation to first sleeve gear 30 . Channel 75 b is formed between output hub 22 and extension 53 and allows for the axial movement of output hub 22 with relation to second sleeve gear 36 . Channel 75 a and 75 b also aid in preventing contamination of lubricant 72 if excluding seals 56 a or 56 b begin to fail and stop preventing substances from migrating towards retaining seals 54 a and 54 b . The design of channels 75 a and 75 b pull contaminants away from retaining seals 54 a and 54 b while gear coupling 10 is in operation.
[0030] To ensure lubricant 72 is retained within gear coupling 10 , besides the use of retaining seals 54 a and 54 b , static seal 68 is operatively arranged between first end plate 50 a and first sleeve gear 30 and static seal 70 is operatively arranged between second end plate 50 b and second sleeve gear 36 . Additionally, static seal 69 is arranged between first sleeve gear 30 and second sleeve gear 36 in order to achieve a tight seal which lubricant 72 cannot pass through since the bolted connection between first sleeve gear 30 and second sleeve gear 36 is not sufficient to keep lubricant 72 within gear coupling 10 . In a preferred embodiment, lubricant 72 is a fluid such as oil, which allows for lubricant 72 to not only have superior friction reducing capabilities, but also allows for the removal and replacement of lubricant 72 within gear coupling 10 by simply removing drain plugs 65 a and 65 b . It should be appreciated, however, that the use of different friction reducing substances is possible and considered to be within the scope of the invention as claimed. For example, a grease could be used within gear coupling 10 .
[0031] It will be appreciated that various features of the above-described invention and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
LIST OF REFERENCE NUMBERS
[0000]
10 gear coupling
12 input hub
14 gear teeth
16 first surface
18 second surface
22 output hub
24 gear teeth
26 first surface
28 second surface
30 first sleeve gear
31 flange
32 gear teeth
33 exterior surface
36 second sleeve gear
37 flange
38 gear teeth
39 exterior surface
40 sleeve
42 retaining plate
44 retaining plate fastener
45 pin
50 a first end plate
50 b second end plate
51 a retaining screw
51 b retaining screw
52 extension
52 a first surface
52 b second surface
53 extension
53 a first surface
53 b second surface
54 a retaining seal
54 b retaining seal
56 a excluding seal
56 b excluding seal
58 a bump stop
58 b bump stop
58 c bump stop
58 d bump stop
60 bolt
62 nut
65 a drain plug
65 b drain plug
68 static seal
69 static seal
70 static seal
72 lubricant
74 a raised edge
74 b raised edge
75 a channel
75 b channel
80 axis | A lubricated gear coupling for transmitting torque between an input shaft and an output shaft, comprising a first hub connected to the input shaft, the first hub comprising at least one gear tooth and a first raised edge, a second hub non-rotatably connected to the output shaft, the second hub comprising at least one gear tooth and a second raised edge, a sleeve gear comprising at least one gear tooth, wherein the first hub and the second hub are arranged within the sleeve gear, the gear tooth of the first hub and second hub corresponding with the gear tooth of the sleeve gear, wherein torque is transmitted from the input shaft to the output shaft with axial, radial, and angular movement occurring between the first hub and the second hub and, a draining means arranged on the sleeve gear, wherein the lubricant can flow through. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
A Continuation-in-Part of FLATLINE METHOD OF DRYING WAFERS (Ser. No. 08/388,075), filed Feb. 14, 1995, now U.S. Pat. No. 5,524,361.
In U.S. Pat. No. 5,524,361 wood wafers of the type used in the manufacture of oriented strand board (OSB) are dried by advancing the wood wafer above a planar surface; heated air is forced upwardly through spaced apart holes defined in the planar surface and through the random array of advancing wafers; then the heated air and accumulated moisture is evacuated from above the advancing wood wafers.
The present application is directed to a method of controlling VOC and NO x emissions in such a flatline wafer drying conveyor system.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Drying of particulate material, such as wood chips (wafers/strands), bark or the like, for manufacture of oriented strand board (OSB).
2. Description of the Prior Art
Pertinent prior patents and publications: being supplied in an Information Disclosure Statement.
Rotary dryers have been utilized to dry wood strands. Applicants' flatline method used in the manufacture of oriented strand board (OSB) eliminates two critical negatives inherent in all rotary drying systems. These are: mechanical and thermal stresses imposed on strands with the subsequent loss of material, and the excessive release of VOCs as a result of drying temperatures in excess of 800° F.
This conventional release of VOC emissions requires the use of additional control equipment with a capital cost and an ongoing utility cost estimated to be unacceptable. The use of add-on control devices was regarded within the oriented strand board (OSB) industry as a necessity in light of provisions set forth in the 1990 Clean Air Act.
SUMMARY OF THE INVENTION
In applicants' MULTI-ZONE METHOD FOR CONTROLLING VOC AND NO X EMISSIONS IN A FLATLINE CONVEYOR WAFER DRYING SYSTEM, portions of the exhausted air stream from the drying process can be delivered to a waste-wood burner (primary heat source) resulting in lower emissions of pollutants to the Environment.
Water and VOCs are released from the wood product in the form of vapor during the drying process and are contained within the air mass circulated through the individual dryer.
As the moisture concentration approaches saturation (Dew Point), the ability of the air to accept additional moisture and hold it in suspension is diminished. This is also true for VOCs. VOCs have a wide range of evaporation temperatures; some VOCs evaporate at lower temperatures than water and some at higher temperatures than water. The VOCs contained within different wood species vary as do the temperatures at which they are released. The environment within individual dryer sections is controlled to optimize the VOC removal for these variations in wood species. By controlling the temperature of the circulated air and the moisture concentration of the air within a given dryer section, it is possible to vary both the VOC and water concentrations of the air stream. Controlling the exhaust air stream from these controlled environments allows for the removal of VOCs at optimum locations within the dryer.
According to the present method, the moisture and VOCs are extracted from the system by means of exhausting variable portions of the vapor-laden air mass at various locations within each dryer zone and replacing this exhausted air with equivalent amounts of fresh air which contain less moisture. When this process is controlled, the moisture content of the air within the individual zones can be maintained at an optimum level to enhance the uniform drying of wafers and to exercise some control over where, within the dryer, the moisture and VOCs are released.
Reduction of VOC emissions into the atmosphere is possible with the utilization of a waste wood burner as the primary heat source and pollution control device. Supplying portions of VOC and moisture laden exhausted air from various dryer exhaust ports to the primary, secondary and tertiary combustion air ports of the wood burner allows the VOCs to be incinerated during the combustion process. Along with the VOCs, water is introduced into the combustion process and reacts differently, but can effect some benefits if introduced in a controlled manner. There is a maximum amount of water that can be introduced to the waste-wood burner during the combustion process. Likewise, there are limits to the amount of water that can be introduced to various locations in the burner. The combustion process takes place in stages within the burner and requires regulation of the fuel and introduction of combustion air at various locations and flow rates to optimize combustion.
Conventionally, nitrogen is introduced into the combustion process via two (2) sources, the combustion air and the organic fuel (waste wood). In order to achieve complete combustion, excess air is introduced to ensure that adequate oxygen is present during the combustion process. The introduction of oxygen results in higher temperatures as the combustion process accelerates. Nitrous Oxides (NO x ) are chemical compounds formed during high temperature combustion. During high temperature combustion NO x and other chemical species become dissociated with the combustion process. The dissociation and equilibriums are exceedingly complex, but generally higher temperatures tend to increase the dissociation while lower temperatures tend to reduce the dissociation of these chemical species. Introduction of water into the combusiton air stream can serve to reduce the combustion temperature; thus, reduce the dissociation of NO x .
Conversely, the introduction of excessive moisture into the combustion air stream can cause a quenching of the combustion flame which results in the formation of alcohols, aldehydes, formic acids, high order acids and carbon monoxide, as well as carbon dixoide and water vapor. Quenching is the result of excessive cooling of the combusiton flame which, in turn, results in incomplete combustion. This suports the premise that the introduction of moisture into the combustion process must be accomplished in a controlled manner.
The exhausted air from the wafer dryers contains VOCs and water vapor. These components are natural by-products of the drying process. The novelty or innovativeness results from the introduction of these components into the combustion process in a controlled manner in order to achieve incineration of the VOCs and benefit from the presence of moisture in the combustion air as a result of the drying process. It is not necessary to equip the burner with an elaborate means of introducing water vapor into the combustion air. Due to the controlled environments within the dryer and the ability to exhaust variable volumes of air from various locations within the dryer, this water vapor is already present in the exhausted air stream. The ability to control the environment within the dryer allows the moisture and VOCS to be removed at controlled rates and supplied to the combustion process in such a manner as to incinerate the VOCs and assist in the control of the combustion process to reduce the dissociation of NO x , thereby reducing the emissions of VOCs and NOx into the atmosphere.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of a flatline wafer drying system entitled "Flow Diagram for Southern Yellow Pine" and embodying three dryer zones of the type which may be utilized according to the present invention.
FIG. 2 is a similar schematic entitled: "Flow Diagram for Aspen".
FIG. 3 is a strand temperature and moisture profile graph.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
One of the most important distinctions between rotary dryers and Applicants' flatline technology is the way in which material is moved through the system. In a rotary system, strands are tumbled and pushed along with hot gases through the cylindrical drying apparatus. Compaction and mechanical damage are common. In addition, gases are typically 800°-1800° F.--a temperature which easily auto-ignites small wood strands and fines. The typical result is a minimum of a 3% loss of wood resources during drying, and a significant fire hazard.
In contrast, Applicants' proposed Flatline Dryer System positively transports wood strands through the dryer without compaction, and without temperature-stressing the material. In this system, a 2 to 12" high mat of wood strands is transported on a steel flatwire belt which rides on a perforated 1/4" thick steel slider. The supply air plenum is located under the perforated steel plate.
Supply air is heated by smooth surface, thermal oil heat exchangers, which are heated with thermal oil from the customer's energy system. Heated air is directed into the supply plenum and forced upwardly through the perforated openings and the 2-12" high mat of wood strands, resulting in moisture removal. In addition, strands are never exposed to temperatures above 500° F.; thus, the OSB producer enjoys the advantage of virtually 100% wood yield through the drying process.
Applicants' system anticipates yields of 35,000 lbs. of oven dried (OD) strands per hour. This is a capacity which is practical and cost-efficient for most OSB producers. The overall length of the three-zone dryer, including in-feed, out-feed and intermittent conveyors is 220 ft.
Extensive testing shows that a three-zone system is most effective for strand processing. Each zone is 60 ft. in length and each of these three zones is further divided into three 20-ft. sections. Each section is served by twin recirculation fans and individually controlled thermal oil heat exchangers. With this system configuration, it is possible to operate with as many as nine independent set point temperatures. This is desirable when multiple wood species are processed together, and when strands have a broad range of moisture content.
Applicants' system is simple and straightforward in its design. It uses standard, commercially available components, and has been engineered so that the majority of maintenance activity can be performed without system shut-down. Applicant's flatline system is also distinctive in that it is floor level and allows easy access for routine maintenance.
The 5-6 minute dwell time common with rotary drying is widely regarded as the benchmark for strand drying when the specification is for an exit moisture content of 2-4% m.c. Rotary systems achieve this goal in 5-6 minutes by starting with air which is heated to between 800° and 1800° F. Applicants' goal was to develop a drying system which could dry strands in 5-6 minutes at temperatures below 400° F.
During its earliest tests, air was blown from above and below the strands, and the flatline prototype achieved a 3% moisture content following an 8.5 minute cycle. By redesigning the system to supply airflow exclusively from below the conveyor, and by introducing mild mechanical agitation, the strands became fluidized, compression was eliminated, and the six-minute goal was achieved. Additional system enhancements included the chance from a balanced weave belt to a flat wire belt, using a smaller opening (with higher static pressure) in the plenum for maximum uniformity in air distribution, and the installation of twin picker rolls which agitate the mat as the strands passed. This became a second means to insure consistent exposure of the strands to heated air and thus insure uniform drying.
Worker safety, insurance costs, the risk of fire-related production stoppage, and the ability to maximize wood yields all depend on the way in which strands are managed within the dryer. Rotary systems have no effective way of isolating dust, fines and small wood particles, and problems with auto-ignition are well-documented. A primary advantage for the flatline system is that wood fines are captured before they have an opportunity to accumulate in the dryer. This was achieved through a design feature integral to the transport conveyor which collects fines continuously and removes them from the dryer. In addition, the design is free of horizontal surfaces and corners where fines and dust can accumulate.
Applicants' flatline system is engineered for predictable, programmed performance with little operator involvement. It is protected by safety interlocks on primary access doors which prevent unauthorized opening and by a comprehensive fire detection/suppression system.
Tests on aspen strands indicate the majority of VOCs are released during zones two and three. This is due to characteristics of the VOCs in the wood, which release at a higher temperature later in the drying cycle. Thus, exhausted airstreams from zones two and three are directed to the energy system as combustion air; exhaust from the initial zone is directed to the multi-clone and ESP.
Applicants' flatline system also benefits the user in that a wider variety of species can be processed. In regions where aspen or Southern yellow pine become less available, or have become more costly, producers can supplement using birch. Birch, which curls at elevated temperatures, can be processed very successfully in the lower heat of Applicants' system.
The constituents emitted as VOCs that OSB producers must be concerned with include tars and resins, fatty acids and terpenes. The organics are liberated at elevated temperatures; the volume of VOCs that must be dealt with is a direct function of how high drying temperatures are, and for how long. Additionally, OSB mills must control the emission of particulate.
Of the tests conducted using Applicants' system, those involving Southern yellow pine--a species comparatively rich in VOCs--were most significant. Tests showed that operating the first dryer zone at 400° F. removed 60% of the moisture and more than 90% of the total VOCs that would be liberated by the drying process. By maintaining dryer zones two and three at just 225° F., drying would be completed with very little additional VOC release. When the timing of the VOC release becomes controllable, what had been a troublesome emission can be turned into a powerful resource. Specifically with Applicants' flatline system, VOC-rich exhaust air from zone one is used as combustion air in the user's energy system. The energy system uses hog fuel--scrap wood from debarking--in a burner which creates high temperature exhaust gas which is passed through the radiant and convection section of the thermal oil system. These high temperature gases elevate the temperature of the thermal oil, which is pumped to heat exchangers in the flatline dryer. The heat exchangers provide the energy to maintain temperature set points of the dryer operation. The customer's thermal oil system is also used to heat the press used to manufacture panels or strandboard following strand drying and the application of resin. Thermal oil systems are also used for facility climate control, and for heating log ponds.
Exhaust air from zones two and three is directed to multi-clones, and then to electrostatic precipitators. These devices are typically necessary regardless of what type of dryer is used.
Applicants' flatline system is managed by integrated controls which use standard PLC/I-O interfaces. The processors are coupled with a computer which runs a model-based software supervisory package. An advanced, easy to use graphic interface serves as the operations control. The system provides anticipatory control by monitoring variables such as moisture content and the weight of incoming strands and making appropriate adjustments. The system also responds to throughput demands from equipment downstream; if, for example, the dry bin level is changing, dryer throughputs are modified accordingly. The model also performs complete self and sensor diagnostics. Backing up the model is a series of basic control functions integral to the PLC which will continue system operation at various default values. The control system performs a broad range of high level manage reporting. It offers easy compatibility with SPC schemes and can make an important contribution to ISO 9000 programs.
OSB producers have calculated the costs of a traditional rotary dryer with add-on control devices vs. Applicants' flatline dryer. Assuming a 35,000 lbs/hr. O.D. production rate, the overcapital cost comparison is competitive. What distinguishes the two alternatives is first, with the rotary dryer, the on-going cost of the natural gas for the RTO, and maintenance on the unit. A second cost difference using the flatline dryer is the 3% higher wood yields provided by the flatline system. If a producer purchases $15 million of wood annually, a 3% savings equates to $450,000 in wood resource savings. A third cost advantage is the ability of the flatline system to accommodate longer strands, as well as wider range of wood species. Longer strands--6" or longer, as opposed to 3.5" strands--means the wood will be cut fewer times, resulting in fewer fractured pieces and less wood fines. Manifestly, this results in improved wood utilization in the manufacturing process.
Applicants' flatline dryer benefits the OSB producer in important ways. It delivers greater yields, facilitates greater flexibility in processing and material feed and offers a dramatic alternative to the cost and complexity of RTO devices. Because the flatline dryer operates at lower heat and more closely controls wood fines, it also offers an important safety advantage over traditional rotary devices. See FIG. 3 for strand temperature and moisture profile during low temperature flatline drying.
I TESTING
Testing was performed for particulate, nitrous oxides (NO x ), carbon monoxide (CO), total hydrocarbons (THC), formaldehyde and phenol emissions.
The particulate matter was sampled according to US EPA Reference Method 5. The stack gas moisture, velocity and volumetric flow rates were also determined during this isokinetic sampling procedure. This data enabled conversion of flue gas pollutant concentrations to emission data values in pounds per hour (lb/hr).
The formaldehyde was sampled according to the EPA Method 0011/8315 procedure entitled "Sampling for Aldehydes and Ketone Emissions from Stationary Sources". The stack gas moisture, velocity and volumetric flow rates were also determined during this sampling procedure. This data enabled conversion of all flue gas pollutant concentrations to emission data values in pounds per hour (lb/hr).
The sampling for gaseous compound concentrations occurred simultaneously with the formaldehyde testing. The volumetric flow determination obtained pursuant to Method 0011 test was used in converting the gaseous concentrations from parts per million (ppm) to pounds per hour (lb/hr).
The gaseous compounds were collected and analyzed by test methods that utilize "real-time" continuous emission monitor (CEM) instrumentation. This technology provides data with a high degree of reliability on-site. Reference Methods 3A, 7E, 10 and 25A were employed for the analysis of oxygen and carbon dioxide, NO x , CO and THC, respectively.
These testing procedures set forth a sampling strategy to continuously extract sample gas from the source. This sample stream is routed to individual CEMs for analysis of the various targeted pollutants and diluent gases. The test results are based on the average value of one-minute averages generated by the CEM instrument data acquisition during the test periods. Three (3) sampling periods were performed in which the gaseous concentrations were continuously monitored for the listed target compounds.
The phenol was sampled according to the EPA Method TO-8 procedure entitled "Method for the Determination of Phenol and Methylphenois (Cresols) in Ambient Air Using High Performance Liquid Chromatography". The purpose of the performance test was to determine if the emissions of the targeted gaseous pollutants from this source are equal to or below the allowable emission limitation established for the appropriate regulatory authorities.
II. TEST RESULTS
Tables A through C report the results of the particulate, NO x , CO, THC, formaldehyde and phenol testing done on this source. The NO x values are reported as nitrogen dioxide, the THC is reported as methane.
Table A tabulates the particulate test results for each test run and are shown in concentration, grains per dry standard cubic foot (gr/dscf) and in emission values of pounds per hour (lb/hr).
TABLE A______________________________________Particulate Test SummaryApril 26, 1996 ##STR1##______________________________________
The NO x , CO and THC results are tabulated for each test run and are shown in concentration, parts per million (ppm), dry basis, on Table B-1 and in emission values of pounds per hour (lb/hr) on Table B-2.
TABLE B-1______________________________________NO.sub.x, CO and THC Concentration SummaryApril 25, 1996 ##STR2##______________________________________
TABLE B-2______________________________________NO.sub.x, CO and THC Emission Summary ##STR3##______________________________________
Table C tabulates the formaldehyde and phenol test results for each test run and are shown in concentration, grains per dry standard cubic foot (gr/dscf) and in emission values of pounds per hour (lb/hr).
TABLE C______________________________________Formaldehyde and Phenol Emission Summary ##STR4##______________________________________ *BDL = below detection limit of .2 mg
During the third run of the total hydrocarbon testing, the process had problems with plugging of the fuel line to the burner. The plant notified the testing crew of the problem and testing was stopped. When the test resumed, the hydrocarbon readings were higher than the previous two runs. The higher readings may be attributed to the time needed for the process to stabilize. The average of all three runs is still below the allowable 30.9 lb/hr.
Benefits of enhanced routing of the exhausted moisture and VOCs to a waste wood burner for incineration include:
I. Each dryer section (comprised of two opposing heater houses) can be equiped with a multitude of exhaust ports. These exhaust ports can be located at a variety of locations within the section to allow for optimum removal of moisture and VOCs.
II. Exhaust ports can be directed singularly or as a plurality to the atmosphere, single or multiple auxiliary pollution control devices (such as Regenerative Thermal Oxidizers, Bio-Filters, Electrostatic Precipitators, etc.), and/or to one or more locations (primary, secondary or tertiary) at the primary waste wood burner as determined to enable a significant reduction of VOCs emitted to the atmosphere.
III. Moisture introduced into the burner reduces the formation and emission of Nitrous Oxides (NO x ) largely due to a reduction in flame temperature. The reduction of NO x emissions wil be offset by an in increase in Carbon monoxide (CO) emissions. This must be monitored and optimized in order to comply with emissions allowances established and permitted by the EPA.
IV. VOCs introduced into the burner become an auxiliary source of fuel and contribute to the energy released by the primary fuel (waste wood). The greater the VOC content of the exhaust air introduced into the burner, the less primary fuel (waste wood) is needed.
V. By regulating the environment within individual sections and zones, it is possible to exhaust VOCs and/or moisture from optimum locations (singular or a plurality of locations) and direct the exhaust stream to the most effective post-dryer pollution control device. When the vast majority of the emissions from a given zone or section is water, it is logical to send the exhaust stream directly to the atmosphere. By controlling the section/zone environments, it is possible to increase the concentration of VOCs released within given locations and route the exhaust from such sections/zones to the waste wood burner for incineration.
VI. Different, wood species release different combinations of VOCs and at different concentrations and conditions. Depending on the wood species and the controlled environment within given sections/zones, it is possible to release large concentrations of water initially in the drying process and route the exhaust from early stages to the atmosphere because of low concentrations of VOCs in the exhausted air streams. Conversely, with some wood species, it appears that much higher concentrations of VOCs can be released in the early stages of drying and the exhaust from these stages can be routed to the waste wood burner for incinertion. Due to the wide variation in wood species and the differences in the release of VOCs, it is necessary to have a multitude of locations to exhaust from. | Environmental enhancement by controlling volatile organic compound (VOC) and NO x emissions in a flatline wafer drying system. The method is characterized by advancing the wafers of the type used in manufacture of oriented strand board (OSB) on a flatline conveyor embodying a plurality of dryer zones. Particularly, heating the dryer zones in successive lower temperatures in the range 500° F. to 200° F. by flowing heated air upwardly through the flatline wafer drying conveyor; removing VOC-rich exhaust air from a primary dryer zone while flowing heated air upwardly therein and removing VOC-rich exhaust air from a secondary dryer zone while flowing heated air from therein. | 5 |
This is a continuation of applications Ser. No. 07/371,092 filed on Jun. 26, 1989 now abandoned.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
This invention relates to a temperature responsive actuator for performing a desired function, such as activating a sprinkler head valve when ambient temperature reaches a predetermined value, also to a novel and improved device for storing, releasing and recovering hydrogen. More particularly, the invention relates to such a temperature responsive actuator making use of a hydride sensor assembly and an actuator assembly wherein when the ambient temperature reaches the predetermined value, hydrogen gas is liberated reversibly from a hydride metal in the hydride sensor assembly and the liberated hydrogen is used to generate gas pressure in a piston or bellows of the actuator assembly which gas pressure, when it attains a certain value, will move the piston or expand the bellows to cause performance of a desired mechanical operation such as operation of the sprinkler head valve.
DESCRIPTION OF THE PRIOR ART
Golben U.S. Pat. 4,377,209 which issued on Mar. 22, 1983 disclosed use of a hydride sensor assembly as a heat sensor and actuator. The hydride sensor assembly of the '209 Patent was connected to a pressure side of an activating piston chamber. Upon reaching a predetermined temperature value, hydrogen gas was released into a chamber containing a piston, and when the gas pressure was sufficient it moved the piston against the force of a spring to cause a pin to pierce a membrane, thus freeing contents of a cartridge for use via an exit port. The piston was sealed by O-rings against the wall of the chamber. The '209 Patent involved destruction of a membrane when the device was actuated.
Earlier Golben U.S. Pat. No. 4,282,931 which issued on Aug. 11, 1981 had described an actuator with a sealed metal bellows. A metal hydride was contained inside the bellows and hydrogen gas was released therefrom by electrical heating. Such a design is obviously not suitable for fast response to ambient air temperature changes.
The teaching of Golben et al. U.S. Pat. No. 4,396,114, which issued on Aug. 2, 1983, also should here be noted. In the '114 Patent a flexible hydrogen storage system employed an axial spring to confine the hydride against an outside wall of a storage system for fast heat transfer. However, available wire sizes limited the radius of curvature of the storage system to approximately 15 cm (6 inches). Sharper bends resulted in the spring opening sufficiently for hydride particles to enter the interior.
OBJECTS OF THE INVENTION
Accordingly, it is an important object of this invention to provide a temperature responsive actuator that overcomes the noted disadvantages of the prior art.
It is another important object of this invention to provide fast response time of approximately 8 seconds for a sprinkler head valve.
It is another important object of this invention to accommodate either piston or bellows operation of a hydride actuated sprinkler head valve.
It is another important object of this invention to provide a temperature responsive actuator that is simple in construction and reliable in operation, particularly as to temperature rating, generated pressure and sufficient piston or bellows displacement.
It is another important object of this invention to provide a temperature actuated fire sprinkler valve that takes up little ceiling height.
It is a further object of this invention to provide a temperature responsive actuator that is resettable, i.e., which, following actuation at a predetermined elevated temperature, when the temperature drops to normal once again, will automatically terminate the temperature related function and return to its original condition, without requiring replacement of any parts.
It is another important object of this invention to provide a temperature actuated fire sprinkler valve that has a built-in time delay for shutoff when the heat source is removed.
It is still another object of this invention to provide a novel and improved device for storing and recovering hydrogen.
The foregoing and other objects, features and advantages will appear more fully hereinafter.
SUMMARY OF THE INVENTION
An actuator embodying the invention performs a function at a predetermined elevated temperature and includes an actuator assembly with a resiliently expandable element and means for liberating hydrogen gas into a sealed system formed in part by the expandable element. When the hydrogen gas pressure in the system becomes sufficiently high, the element expands to perform the function. The expandable element is a piston or bellows and the hydrogen gas liberating means is a hydride sensor assembly. The actuator assembly also includes a housing having first and second ends, a base member having an external cylindrical surface and a circular surface terminating at one end thereof and located within the housing intermediate the first and second housing ends. In one embodiment the bellows surrounds the external cylindrical surface and has a closed end covering the circular surface and an open end secured to the base member in hydrogen gas sealing relationship therewith. A piston has a first end within the housing and confronting the closed bellows end and a second end adjacent the second housing end. A spring within the housing biases the piston toward the bellows, and the base member further includes a hydrogen gas passage having a first end and a second end in communication with the interior of the bellows. In another embodiment a piston, with O-ring or quad ring seals, operates within a cylinder and the bellows is eliminated. As will be understood by those skilled in the sprinkler art, the configuration and location of the housing, piston and biasing spring may be modified to facilitate coupling of the actuator to a device to be controlled.
The hydride sensor assembly includes an outer metallic tube containing flexible tubular means porous to passage of hydrogen gas therethrough and spaced from an inner wall thereof and providing a hydrogen gas passage therein, and hydriding alloy powder in an annular volume between the inner wall of the tube and the tubular means. The tube has a closed end and an open end in hydrogen gas sealed communication with the first end of the hydrogen gas passage of the base member.
When the temperature of the hydriding alloy powder is raised to a predetermined value, desorption of the hydriding alloy powder takes place, liberating hydrogen gas into the hydrogen gas passage within the sensor assembly and thence into the hydrogen gas passage in the base member and subjecting the piston and/or bellows to internal pressure which, upon attainment of a specific value, will cause the closed end of the bellows to move the piston against the resistance of the spring, to perform a temperature responsive function. Reducing the temperature of the hydriding alloy powder results in the reabsorption of the hydrogen gas and returns the assembly to its initial position.
Use of the actuator is disclosed in combination with a normally closed valve assembly having an inlet side and an outlet side, a water line for supplying water to the inlet side and a sprinkler head attached to the outlet side. A portion of the hydride sensor assembly tube is coiled and wrapped around the sprinkler head, and the piston is positioned to open the valve assembly at a predetermined sensor temperature, thus to activate the sprinkler head. The sprinkler is turned of and reset when the sensor temperature cools below the predetermined thermal value.
Many other uses are also possible for either normally open or closed valves, self-locking valves, manual reset valves, actuation with increasing or decreasing temperature, thermostats, regulators and remote sensors. Uses requiring fast response, large forces and noncondensable gases are especially favored.
DESCRIPTION OF THE DRAWING
FIG. 1 is an elevational, partly schematic view of an actuator which shows one preferred embodiment of this invention, including an actuator assembly and a hydride sensor assembly;
FIG. 2 is an axial sectional view of the actuator assembly of FIG. 1, taken on line 2--2 of FIG. 1;
FIG. 3 is a broken view of the hydride sensor assembly of FIG. 1 in uncoiled condition;
FIG. 4 is an enlarged fragmentary sectional view of the hydride sensor assembly taken on line 4--4 of FIG. 3;
FIG. 5 shows the actuator of FIGS. 1, 2, 3 and 4, in a normally closed valve adapted as a sprinkler head assembly;
FIG. 6 is a fragmentary axial sectional view of a device for storing and recovering hydrogen;
FIG. 7 is an enlarged fragmentary sectional view of a manual reset actuator with a locking mechanism; and
FIG. 8 is a fragmentary axial sectional view of another embodiment of the actuator contemplated herein.
DESCRIPTION OF THE INVENTION
FIG. 1 shows an idealized temperature responsive actuator 20 which includes an actuator assembly 22 and a hydride sensor assembly 24. Actuator assembly 22 also is shown in FIG. 2 and hydride sensor assembly 24 in FIGS. 3 and 4.
Actuator assembly 22 includes a cylindrical housing 26 about 2.55 inches (6.5 cm) in length, 0.75 (1.9 cm) in outside diameter with a wall thickness of about 0.0625 inch (0.16 cm) from a first end 28 to a location spaced about 0.125 inch (0.32 cm) from a second end 30, at which location the wall thickness is increased to about 0.1875 inch (0.48 cm), providing a cylindrical hole 32 about 0.375 inch (0.95 cm) in diameter and providing a frustoconical internal flange surface 34 facing away from end 30. Housing 26 may be of suitable metallic material, such as brass.
Actuator assembly 22 also includes a cylindrical brass base member 36 that is assembled with housing 26. Base member 36 has an annular surface 38 perpendicular to the axis of member 36 and abutting end 28 of housing 26, an external cylindrical surface 40 about 0.59 inch (1.51 cm) in diameter and 0.1875 inch (0.48 cm) in axial extent. The end of surface 40 remote from surface 38 is terminated by an annular surface 42 perpendicular to the axis of member 36 and facing in the same direction as annular surface 38. A cylindrical surface 44 about 0.5 inch (1.3 cm) in diameter upstands from the inner periphery of surface 42 and is about 0.1875 inch (0.48 cm) in axial extent. The end of surface 44 remote from surface 42 is terminated by an annular surface 46 perpendicular to the axis of member 36 and facing the same direction as annular surfaces 38 and 42. An external cylindrical surface 48 about 0.344 inch (0.87 cm) in diameter upstands from the inner periphery of surface 46 and is about 1.0625 inches (2.70 cm) in axial extent. The axial end of surface 48 remote from surface 46 terminates in a circular end surface 50 perpendicular to the axis of member 36 and providing an end of member 36.
Member 36 also has a cylindrical surface 52 depending from the outer periphery of annular surface 38 and having a diameter of about 0.75 inch (1.9 cm) and about 0.094 inch (0.24 cm) in axial length. The axial end of surface 52 remote from surface 38 is terminated by an annular surface 54 perpendicular to the axis of member 36 and facing in the direction opposite that faced by surface 38. Depending from the inner periphery of surface 54 is a cylindrical surface 56 coaxial with member 36 and about 0.406 inch (1.03 cm) in diameter. Member 36 continues on to a circular surface 58 perpendicular to the axis of member 36 and providing another end of member 36. Surface 58 is located about 0.50 inch (1.27 cm) from surface 54 and member 36 is provided with 0.375 inch (0.95 cm) diameter external pipe threads 60 extending from surface 58 toward surface 54.
Member 36 is provided with an axial hole 62 about 0.039 inch (0.10 cm) in diameter, produced by a #60 drill, extending from surface 50 to surface 58, and in open communication with both such surfaces. Hole 62 provides base member 36 with a hydrogen gas passage.
Actuator assembly 22 further includes a closed end flexible metal bellows 64, which in a satisfactory embodiment of the invention is a Cliflex brass bellows of 0.531 inch (1.35 cm) outside diameter. Bellows 64 is assembled onto base member 36 with the closed end of bellows 64 covering circular end surface 50 of base member 36 and the expandable body portion of bellows 64 surrounding cylindrical surface 48 of base member 36. The open end of bellows 64 surrounds cylindrical surface 44 and is soldered thereto to as indicated at 66 to provide a hydrogen gas seal therewith, thus forming a subassembly of base member 36 and bellows 64.
Actuator assembly 22 also includes a brass piston 68 having a cylindrical base portion 70 surmounted by a cylindrical intermediate portion 72 in turn surmounted by a cylindrical shaft portion 74. Portions 70, 72 and 74 are coaxial, and portions 70 and 74 provide piston 68 with first and second circular ends 76 and 78, respectively. Portion 70 has a diameter of about 0.562 inch (1.43 cm) and an axial length of about 0.094 in (0.24 cm). Portion 72 has a diameter of about 0.406 inch (1.03 cm) and an axial length of about 0.094 inch (0.24 cm). Portion 74 has a diameter of about 0.3125 inch (0.79 cm) and an axial length of about 1.06 inch (2.70 cm). The axial length of piston 68 from end 76 to end 78 is about 1.25 inch (3.18 cm). The juncture of portions 70 and 72 provides an annular flange surface 80 facing away from end 76, and the juncture of portions 72 and 74 provides an annular flange surface 82 facing away from end 76.
Actuator assembly 22 further includes a coil spring 84 of wire 0.050 inch (0.13 cm) in diameter wound to a coil diameter of 0.525 inch (1.33 cm) and having an axial length when unstressed of about 1.55 inch (3.94 cm).
Actuator assembly 22 is completed by inserting spring 84 into first end 28 of housing 26, followed by piston 68, end 78 first, and then the sub-assembly of base member 36 and bellows 64, the closed end of bellows 64 first, until base member surface 38 abuts end 28 of housing 26, and securing these parts together by diametrically opposed screws 86 that are passed through holes in the wall of housing 26 and into threaded engagement with tapped holes 88 in surface 40 of base member 36. In the assembled condition, the closed end of bellows 64 engages end 76 of piston 68, and spring 84 is axially compressed between piston surface 80 and frustoconical housing surface 34, with piston portion 72 within spring 84, and end 78 of piston 68 projecting beyond second end 30 of housing 26.
When bellows 64 is not internally pressurized by hydrogen gas, spring 84 maintains the closed end of bellows 64 against circular end surface 50 of base member 36 and piston end 78 projects about 0.125 inch (0.32 cm) beyond second housing end 30. In this condition, spring 84 produces a 20 pound (9.08 kg) force against the closed end of bellows 64. Bellows 64 has an effective area of about 0.214 square inch (1.38 cm 2 ) and a maximum rated pressure of 390 psig. A hydrogen gas pressure of 93.5 psig (20/0.214) is required to produce a force of 20 pounds (9.08 kg). For hydrogen gas pressure exceeding this value, the resistance of spring 84 will be overcome and movement of piston 68 will be initiated.
The configuration of base member 36 minimizes the volume enclosed between base member 36 and bellows 64, and base member 36 prevents bellows 64 from moving in compression. Housing 26 acts as a safety shield should bellows 64 become overpressurized for some reason.
Hydride sensor assembly 24 includes an outer copper refrigerator tube 90 having an outside diameter of 0.125 inch (0.32 cm), a wall thickness of 0.014 inch (0.036 cm) and a length of 12 inches (30.5 cm). Tube 90 passes through a drilled out 0.125 inch (0.32 cm) male pipe plug 92 having external threads 93. Tube 90 has an open end 94 that projects about 0.25 inch (0.64 cm) beyond plug 92. Tube 90 and plug 92 are soft soldered together. Tube 90 also has a closed end 96 where tube 90 is pinched closed and soft soldered to seal same.
As shown in FIG. 4, tube 90 contains flexible tubular means porous to the passage of hydrogen gas therethrough, illustrated in the form of a stainless steel garter spring 98 coaxial with tube 90. Spring 98 is about 12 inches (30.5 cm) long and has an outside diameter of about 0.065 inch (0.17 cm). One end of spring 98, plugged with a drop of high temperature silicone rubber (RTV) thereon, engages closed end 96 of tube 90. The other end of spring 98 is substantially flush with end 94 of tube 90.
The annular volume between the inner surface of tube 90 and spring 98 is filled with about 0.13 ounces (3.7 grams) of finely ground (-80 mesh) hydriding alloy powder 100 to a packing density of 2.68 ounces/in 3 (4.64 grams/cm 3 ), and the end of the annular volume at open end 94 of tube 90 is sealed with a bead of RTV. The fine hydriding alloy powder is produced most conveniently by hydride/dehydride grinding. When the actuator has been assembled and prior to use, powder 100 must be activated (hydrided). This activation can be accomplished in known fashion.
Spring 98 serves to provide a hydrogen gas passage therein and to position hydriding alloy powder 100 against the inner wall of tube 90.
The internal construction of hydride sensor assembly 24 as shown closely follows the teachings of the aforementioned Golben et al. '114 Patent.
The portion of tube 90 between pipe plug 92 and closed tube end 96 is coiled into a helix about 2 inches (5.08 cm) in diameter, and actuator assembly 22 and hydride sensor assembly 24 are joined by a 0.125 inch (0.69 cm) brass tee 102 (FIG. 1), threads 60 and 93 being screwed into tee 102. The joint with assembly 22 is soft soldered while the joint with assembly 24 is Teflon taped to permit replacement of assembly 24 should the need arise. Tee 102 has a tee branch 104 that is closed by a pipe plug 106 which is Teflon taped to permit access for hydride activation and pressure calibration, in known fashion. Both taped joints can be soft soldered for leak-free hydrogen service.
It is apparent that, with plug 106 in place, a closed hydrogen gas system is provided by tube 90, tee 102, hole 62 in base number 36 and the inside of bellows 64.
EXAMPLE 1
Four hydride actuators were assembled according to FIGS. 1, 2 and 3. A Cliflex flexible metal bellows (17/32" OD, closed end, brass, 390 psig internal working pressure) was used. Approximately 4 grams of LaNi 5 powder was placed in the sensor tube. The reversible metal hydride former was activated in the usual manner. The sensor tube was then immersed in a 25° C. water bath and the hydrogen gas pressure equilibrated at 60 psia. The actuator was then sealed.
Two types of evaluation tests were performed on the hydride actuators. In the static tests, the sensor tube is immersed in the water bath and heated at a rate of 0.5° C./min. Bath temperature and piston displacement are monitored. Force developed by the actuator is determined by the displacement and the calibrated spring constant. A 30 lb force (corresponding to a 0.300" piston displacement) was obtained at 66° C. (151° F.).
Dynamic tests of the hydride actuators are obtained by plunging the sensor tube into a flowing (2.56 m/s; 8.3 ft/s) air stream at 135° C. (275° F.). Response time for a 0.300 inch displacement varied between 10.50 to 12.79 seconds in 30 tests (3 actuators, 10 tests each).
The force and response values obtained in Example 1 are suitable for the on-off actuation of a fire sprinkler. This is illustrated in FIG. 5 by adapting the hydride actuator to fit a 1/2 Globe valve. FIG. 5 shows hydride actuator 20 assembled with a normally closed valve assembly 110 having an inlet side 112 and an outlet side 114. A water line (not shown) supplies water to inlet side 112 and a sprinkler head 118 is attached to outlet side 114 of valve assembly 110. Valve assembly 110 and sprinkler head 118 are shown mounted respectively above and below a ceiling 120, through which tube 90 passes, and an escutcheon plate 122, tube 90 being wrapped around sprinkler head 118.
When the temperature of sprinkler head 118 and the portion of tube 90 wrapped therearound rises to a predetermined value, desorption of hydriding alloy 100 occurs and hydrogen gas is liberated in an endothermic reaction. When the hydrogen gas pressure attains a predetermined value, bellows 64 will expand axially, overcoming the resistance of spring 84 and moving piston end 78 further from second housing end 30. In a satisfactory example (Example 1) of the invention, this movement occurs when the hydrogen gas pressure exceeds 93.5 psig. A 0.1 inch (0.25 cm) travel of piston 68 is sufficient to open valve assembly 110 to permit water to flow therethrough from water line 116, thus activating sprinkler head 118. Upon subsequent cooling, absorption of hydriding alloy 100 occurs and it takes back the hydrogen gas in an exothermic reaction, reducing the hydrogen gas pressure and permitting spring 84 to return piston 68 and bellows 64 to the original positions shown in FIG. 2, and closing valve assembly 110. Piston end 78 bears against an axially movable member 124 which in turn bears against an additional axially movable member 126 which is biased by a spring 128 to be in a position in which it normally closes the water passage between inlet side 112 and outlet side 114 of valve assembly 110.
LaNi 5 , the prototypical hydriding alloy, has pressure-temperature characteristics very close to the desired values, and it is assumed herein without limitation that the alloy used for hydriding alloy powder 100 is LaNi 5 , possibly modified by small additions of Fe, Co, Al or Sn, to adjust temperature response.
Other changes can also be made, with similar effect. For example, if the stiffness of spring 84 is increased, the hydrogen gas pressure for actuation, and consequently the rated temperature, will increase. Alternatively or additionally, the diameter of bellows 64 may be decreased, with similar effect.
The internal volume (hydrogen volume) of the system has a pronounced effect on the quantity of hydride required and the actuator response time. The smaller the internal volume, the smaller the quantity of hydrogen gas required to produce a specified force. Less hydrogen gas means less hydride former required or alternatively a greater hydrogen reserve. Less hydrogen gas also means faster response time when the quantity of hydride and the heat transfer rate of the hydride are constant.
FIG. 6 illustrates a device 130 for storing and recovering hydrogen. Device 130 comprises an outer tube 132 and an inner, nonmetallic tube 134 porous to the passage of hydrogen gas therethrough and disposed within outer tube 132. Outer tube 132 has an inner surface 136 and inner tube 134 has an outer surface 138, surfaces 136 and 138 confronting and spaced from each other to provide an annular volume therebetween. The annular volume contains hydriding alloy powder 100. The interior of inner tube 134 provides device 130 with a hydrogen gas passage 142. Outer tube 132 is bendable and is fabricated of heat conducting material such as copper and inner tube 134 is flexible, whereby device 130 can assume various configurations. Inner tube 134 is fabricated of thermoplastic material, of which polyethylene, polypropylene and Teflon are suitable examples. Tube 132 has a closed end 96 where tube 132 is pinched closed and soft soldered to seal same.
Inner tube 134 can be substituted in hydride sensor assembly 24 for stainless steel garter spring 98, with certain advantages. One such advantage is that device 130 can be bent to a much smaller coil diameter than is possible with garter spring 98. This advantage is achieved because with spring 98 there is a gap which increases with decreasing coil diameter, thus causing a problem as to retention of hydriding alloy powder. With tube 134, there is no such gap. Furthermore, the use of tube 134 results in a cost saving, in that tube 134 costs roughly only about 1/3 as much as an equal length of stainless steel garter spring 98. Additionally, the use of tube 134 facilitates fabrication because tube 134 does not need to be wrapped with any material such as is disclosed in the aforementioned Golben et al. '144 Patent.
EXAMPLE 2
A manual reset hydride sensor actuator 150 was fabricated as shown in FIG. 7. The function of this actuator is automatically to close a valve in response to an ambient air or process liquid temperature change. The details of the hydride sensor, base and expandable element are similar to those shown in FIGS. 2, 3 and 4. A Nupro B4-HK4 valve 155 was selected for actuation. The actuator housing 158 and piston 159 were modified to fit the valve and permit spring insertion of a lock pin 161 into the piston 159 at its closed position.
Closure is accomplished by expansion of a metal bellows 163 as hydrogen gas pressure increases in a hydride temperature sensor. The valve 155 is locked in the closed position by a spring 165 inserting a lock pin 161 into the piston 159. When the temperature of the hydride sensor returns to normal, the valve 155 can be reopened by manually removing the lock pin 161.
Tests were conducted with the actuator assembly shown in FIG. 7 connected to a 1000 psig helium line. Four grams of LaNi 5 were placed in the sensor tube. Ambient air temperatures ranged from 21° to 26° C. The actuator 150 closed in 4 seconds when the sensor coil was dipped into a 68° C. water bath. The actuator also closed in 4 seconds when sensor coil was heated with 135° C. air flowing at 8.3 feet per second.
EXAMPLE 3
In fire sprinkler applications it is desirable frequently to provide in-line valving organized to take up little ceiling height. Toward this objective hydride sensor actuator 180 was fabricated as shown in FIG. 8. Actuator 180 was fabricated from 1/16 outside diameter stainless steel tubing with 0,005" wall thickness. The function of the actuator 180 is automatically to operate a valve 182 in response to an ambient air temperature change. Details of the hydride sensor, base and expandable element are substantially similar to those shown and described for FIGS. 2, 3 and 4. Closure is provided by movement of a piston 184 as hydrogen gas pressure increases in the hydride sensor actuator. The piston 184 is sealed by means of quad rings 186.
A further feature of the embodiment of FIG. 8 resides in the inclusion of a small check valve 188 in hydrogen gas passage 190. Check valve 188 is positioned to oppose flow of hydrogen back to the hydride sensor actuator 180. A small hole (not shown) and porous plug (not shown) are inserted in the base of the check valve 188 to retard, but not prevent, return of hydrogen to the sensor actuator 180. Said arrangement provides time delay control of shutoff of a fire sprinkler. The check valve 188 shown in FIG. 8 is fitted with a Mott 5000 --1/8th inch--1 cc/min. porous flow control element. Shutoff is delayed for 72 seconds. For applications in which fast response is not required, a porous plug inserted directly into hydrogen passageway 190 provides time delay control for shutoff.
The actuator shown in FIG. 8 was connected to a 50 psig waterline. Hot air, 275° F., was directed at the temperature sensor. The flow rate of the hot air was 250 feet per minute. The actuator turned on in 6 seconds.
The disclosed details are exemplary only and are not to be taken as limitations on the invention except as those details may be included in the appended claims. | An actuator for performing a function at a predetermined temperature includes an actuator assembly with a resiliently expandable element and a device for liberating hydrogen gas into a sealed system formed in part by the element. When the hydrogen gas pressure in the system becomes sufficiently high, the element expands to perform the function. The resiliently expandable element is a piston or a bellows and the device for liberating hydrogen gas is a hydride sensor assembly. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an arcuate side molding which is capable of being attached to an arcuate portion of an automobile body such as a tire housing of an automobile body.
2. Description of the Prior Art
It has hitherto been difficult to attach a side molding to an arcuate portion of an automobile body such as a tire housing. No hole has been formed in such a portion because it is difficult to form holes in an arcuate portion of an automobile body in the pressing process of manufacturing and a tire housing is liable to be corroded if any hole is formed therein. Accordingly, it has been usual merely to attach a small side molding directly to an automobile body with an adhesive tape. The thermal expansion coefficient of the side molding is different from that of the automobile body. Therefore, the direct attachment of the side molding to the automobile body has easily caused thermal deformation to the side molding relative to the automobile body, for example, in a hot day in summer.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made to solve these problems in the conventional side molding, and it is an object of the present invention to provide an arcuate side molding which can be easily attached to an arcuate portion of an automobile body in a manner of being capable of absorbing thermal deformation of the side molding.
An arcuate side molding of the present invention comprises: a resin plate composed of a first molding portion which has a strip shape corresponding to an arcuate portion of an automobile body and a second molding portion which has a larger width than that of the first molding portion and is extended from one end of the first molding portion, a plurality of engaging projections being formed on the backside at least of the first molding portion and; an intermediate member made of metal having an adhesive surface for at least partially adhering to the automobile body and slots which are formed in the positions corresponding to the engaging projections of the first molding portion, the longitudinal direction of which is approximately parallel to that of the first molding portion, wherein the engaging projections formed on the first molding portion of the resin plate are engaged in the slots of the intermediate member in a way that the resin plate and the intermediate member are longitudinally slidable to each other.
DETAILED DESCRIPTION OF THE INVENTION
An arcuate resin plate employed in the present invention comprises a first molding portion and a second molding portion extended from one end of the first molding portion. The second molding portion may be extended from both ends of the first molding portion. The first molding portion has a strip shape corresponding to an arcuate portion such as a tire housing of an automobile body. Accordingly, the lower part of the first molding portion forms an arc shape. A plurality of projections for engaging the resin plate to the automobile body are formed on the backside of the first molding portion, and may also be formed on the backside of the second molding portion. The resin plate is formed by injection molding an optional resin such as vinyl chloride and polypropylene. An intermediate member is attached to the backside of the resin plate. Generally, a sheet steel which is press formed to conform with the automobile body is employed as an intermediate member. The intermediate member has an adhesive surface for adhering to the outer surface of the automobile body. The intermediate member has a plurality of slots in a manner that the longitudinal direction of the slots is approximately parallel to that of the first molding portion. The engagement of the intermediate member with the the resin plate is achieved by inserting the engaging projections formed on the backside of the resin plate into the slots in the intermediate member and then heating the tips of the projections to be pressed and make thick heads (heat caulking), or by forcibly inserting the projections with thick heads into the slots which are narrower than the thick heads of the projections by use of the elasticity of the projections. The intermediate member is disposed at least on the first molding portion of the resin plate. It is preferable to form slidable projections on the backside of the second molding portion of the resin plate. The slidable projections on the second molding portion are to be inserted into and engaged with holes in the automobile body so as to be slidable in the longitudinal direction of the second molding portion.
The arcuate side molding of the present invention can be attached to the automobile body by means of an adhesive tape and the like stuck to one surface of the intermediate member. In the present invention, the intermediate member is slidably attached to the backside of the resin plate. Therefore, the slidablity of the engagement can absorb the thermal deformation due to the difference of thermal expansion coefficient of the automobile body and the resin plate.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will become apparent from the following description of a preferred embodiment thereof taken in connection with the accompanying drawings in which:
FIG. 1 is a sectional view illustrating the constitution of an arcuate side molding in a preferred embodiment according to the present invention;
FIG. 2 is a perspective view of an automobile body showing arcuate side moldings of the present invention as attached to the automobile body;
FIG. 3 is a plan view of an intermediate member employed in the arcuate side molding of FIG. 1;
FIG. 4 is a plan view of the backside of the arcuate side molding of FIG. 1;
FIG. 5 is a plan view of projections formed in a first molding portion by means of heat caulking;
FIG. 6 is a cross-sectional view of the projections shown in FIG. 5;
FIG. 7 is a side view of a mounting member with projections; and
FIG. 8 is a plan view of the mounting member with projections.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention will be described in detail hereinafter with reference to a preferred embodiment thereof. FIG. 1 is a sectional view of an arcuate side molding 1 in a preferred embodiment according to the present invention, illustrating the constitution thereof. FIG. 2 is a perspective view of an automobile body showing arcuate side moldings 1 of the present invention as attached to the automobile body 2. A resin plate 4 is formed by injection molding polypropylene resin. The resin plate 4 comprises a first molding portion 40 and a second molding portion 41. The lower side of the first molding portion 40 forms an arc shape. A plurality of projections 6 are formed on the backside of the first molding portion 40 of the resin plate 4. An intermediate member 5, which is made of a sheet steel, has a plurality of slots 52, as shown in FIG. 3. The longitudinal direction of the slots 52 is approximately parallel to the longitudinal direction of the first molding portion 40. As shown in FIG. 1, the intermediate member 5 is bent to conform with an automobile body 2. The intermediate member 5 has two projected tracks the top surfaces of which form adhesive surfaces 54 and 56 for adhering to the outer surface of the automobile body 2. The intermediate member 5 is attached to the backside of the resin plate 4 by inserting the engaging projections 6 formed on the backside of the resin plate 4 into the slots 52 of the intermediate member 5 and then heating and pressing the tips of the projections 6 so as to deform and make thick heads 60. Thereby, the intermediate member 5 is not easily separated from the resin plate 4. FIGS. 5 and 6 show the heads 60 of the projections 6 deformed by heat caulking. In the caulked state, when a load such as thermal stress is applied to the arcuate side molding 1 according to the present embodiment, the intermediate member 5 and the resin plate 4 are slidable to each other in the longitudinal direction, i.e., the direction of arrow B of FIG. 6.
Slidable projections 8 are formed in the backside of the second molding 41 of the resin plate 4. As shown in FIGS. 7 and 8, a slidable projection 8 comprises a holding member 80 which is formed on the backside of the second molding portion 41 and a mounting member 81 made of resin. The mounting member 81 further comprises a plate portion 81a, a shaft portion 81b perpendicularly installed on the plate portion 81a, a head portion 81c formed on the end of the shaft portion 81b, and arm portions 81d which are formed on the shaft portion 81b. The holding member 80 has a slit 80a to which the plate portion 81a of the mounting member 81 is inserted. The holding member 80 constituting the slit 80a includes taper portions 80b and 80c and arcuate portion 80d. The insertion of the plate portion 81a of the mounting member 81 to the slit 80a of the holding member 80 enables the sliding movement of the mounting member 81 in the direction of arrow A in FIGS. 4 and 8, i.e., the longitudinal direction of the second molding portion 41.
Next, the attachment of the arcuate side molding 1 to an automobile body is explained hereinafter. The adhesive surfaces 54 and 56 of the intermediate member 5 are attached to the outer surface of the automobile body 2 by means of adhesive tapes 72 and 74. At the same time, the head portions 81c of the projections 8 are inserted into the holes in the automobile body 2, thereby attaching the second molding portion 41 to the automobile body 2, as shown in FIG. 1.
As apparent from the foregoing description, the arcuate side molding according to the present invention is constructed by slidably attaching a resin plate having a first molding portion which conforms with the arcuate portion of the automobile body to the intermediate member having approximately the same shape as that of the resin plate. Accordingly, the arcuate side molding can be easily and simply attached to the automobile body by adhesively fixing the intermediate member to the automobile body by means of adhesive tapes or the like. When the resin plate is made of polypropylene resin, adhesives and adhesive tapes are unable to attach the resin plate directly to the automobile body. Therefore, the arcuate side molding of the present invention is particularly effective when the resin plate of the present invention is made of polypropylene resin. Also, since the resin plate is slidable relative to the intermediate member, the thermal deformation attributable to the difference between the resin plate and the intermediate member can be obviated.
Although the invention has been described in its preferred form with a certain degree of particularity, obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that the present invention may be practiced otherwise than as specifically described without departing from the spirit or scope of the appended claims. | An arcuate side molding to be attached to a curved surface of an automobile body avoiding holes being formed therein. The arcuate side molding comprises a resin plate having projections formed in the backside thereof, and an intermediate member provided with slots for receiving the projections of the resin plate. In assembling the resin plate and the intermediate member, the projections are inserted through the slots of intermediate member, and then the tips of the projections are heat caulked to join the intermediate member to the resin plate so that the resin plate is slidable relative to the intermediate member and the resin plate will not be separated from the resin plate. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to the detection of breaks within a structure.
It applies particularly, although not exclusively, to the detection of breaks within a cable, such as a suspension bridge main suspension cable.
The main parts of a suspension bridge are recalled schematically in FIG. 1 . This shows a suspension bridge comprising a deck 1 providing continuity of the carried way and the distribution of the forces. Hanger cables 2 support the deck and transmit the forces to the main suspension cables 3 to which they are securely attached by hanger cable collars. The main cables 3 , which adopt a parabolic appearance, provide the support function. The forces can be broken down into a vertical reaction absorbed by the towers 5 , and a tensile force transmitted by an anchor cable 4 securely attached to an anchor.
The integrity of a construction such as this relies in the ability of the main cables 3 , of the hanger cables 2 and of the anchors to withstand the stresses resulting from the transfer of force, over an extended period of time.
These elements are thus the weak points of suspension bridges. Safety and endurance are therefore generally ensured by adopting suitable safety factors, especially as there is no redundant load path in such constructions.
The main suspension cables 3 usually consist of metal strands, generally made of steel, which are substantially parallel (although the strands are sometimes twisted). These strands are protected against corrosion by various means: heat treatment, chemical treatment, the application of paint, sheathing, etc.
However, it is impossible to rule out entirely the possibility of some of the strands that make up such main suspension cables breaking as a result, for example, of oxidation. This phenomenon is insidious because it mainly affects the internal strands around which water may infiltrate and stagnate without being eliminated by evaporation and without being immediately visible.
The substantially parallel configuration of the metal strands of the main suspension cables means that these strands rub together to a certain extent, thus limiting the extent to which any strand or strands that has or have broken retreat(s) away from a region surrounding the break point.
There then occurs what is known as re-anchorage, that is to say that, beyond this zone, the broken strands continue to contribute to the transmission of force and find themselves once again under stress. Only the break zone has a cross section that is reduced by the cross section of the broken strands and therefore a higher stress is exerted on the remaining strands in this zone. This may cause the remaining strands in the breakage zone to break if the permissible stress is exceeded. If the cause of the breakage of the initial strand or strands is still present in this zone, then this risk becomes more of a reality.
For these reasons, it is therefore important to have reliable and early detection of any break that may have occurred within such a cable, or within any other structure subjected to possible tensile or compressive forces.
It is known practice to detect the onset of breakage within a cable using an acoustic examination of the cable. The energy released as a constituent strand of the cable breaks is thus picked up and recorded using a microphone. However, this technique is able to detect breakage only at the instant at which it occurs. It does not directly provide the history of the number of breaks nor does it give any deterministic indication as to the condition of the cable. Neither is it able to characterize the breaks that have occurred directly, particularly in terms of their location and their extent.
It is a first object of the present invention to alleviate the disadvantages of the known art.
One object of the invention is more specifically to detect breaks that may have occurred within a structure such as a cable.
Another object of the invention is to characterize the breaks, particularly in terms of their location and extent.
SUMMARY OF THE INVENTION
The invention thus proposes a method for detecting a break within at least a portion of a structure, this portion being delimited by a first and a second point of reference of the structure, said portion having a predetermined stiffness in the absence of break and it being subjected to a tensile or compressive force. The method comprises the following steps:
detecting at least one variation in length within the portion of the structure, in response to a variation in the tensile or compressive force applied to said portion; deducing whether or not there is a break within said portion of the structure from the detected variation in length.
This method thus makes it possible to detect any possible breaks that might be within the structure.
The following embodiments are also provided for within the scope of the present invention, alone or in any feasible combination:
the variation in the tensile or compressive force applied to said portion is predetermined, and the deduction as to whether or not there is a break within the portion of the structure is made also on the basis of the predetermined stiffness of said portion and of said predetermined variation in the tensile or compressive force applied to said portion; at least two zones are defined in the length of the portion of the structure; a variation in length is detected relative to at least some of said zones, and whether or not there is a break within at least some of said zones is deduced from the detected variations in length. Any break or breaks that may have occurred within the structure can thus be located with a certain degree of accuracy; respective wires are stretched, one of them between one end of each of said zones and a respective rotary element connected to the first point of reference of the portion of the structure, and the other of them between said rotary element and the second point of reference of the portion of the structure, and the variation in length relative to at least some of said zones is detected from a rotation performed by said respective rotary element in response to the variation in the tensile or compressive force applied to the portion of the structure; the rotary element connected to the first point of reference of the portion of the structure comprises a pulley over which the respective wire passes; the rotation performed by the pulley is detected using a rotary sensor attached to the pulley rotation axle; the rotation performed by the pulley is detected using a linear displacement transducer coupled to the pulley; the rotation performed by the pulley is detected using the linear displacement transducer collaborating with a lever arm extending across a diameter of the pulley; a force measurement device is coupled to the rotation axle of the pulley and is designed to measure a displacement of the respective wire, and the variation in length relative to at least some of said zones is also detected from said measurement of the displacement of the respective wire; the rotary element connected to the first point of reference of said portion of the structure comprises a rotary arm to the ends of which strands of the respective wire are respectively connected; a force sensor is associated with each wire to measure a force exerted on the wire on each side of the respective rotary element, and the variation in length relative to at least some of said zones is also detected from measurements of the force exerted on the respective wire; a wire is stretched between the first and second points of reference of the portion of the structure in the form of a network of a number of rotary elements which are alternately connected to the first point of reference of the portion of the structure and to one end of each of said zones; the variation in length relative to at least some of said zones is detected from a rotation performed by at least one respective rotary element of said network in response to the variation in the tensile or compressive force applied to the portion of the structure; said wire is connected to two points of the first point of reference of the portion of the structure; the variation in the tensile or compressive force applied to said portion is predetermined, and a proportion of the cross section of said portion of the structure that has experienced a break is also deduced from said predetermined variation in the tensile or compressive force applied to said portion and from the detected variations in length, at least in some of said zones; the variation in the tensile or compressive force applied to the portion of the structure is progressive and at least some of the steps of the method are repeated at several instants during this progression; further zones are then defined in the length of the portion of the structure, which are more concentrated around the zones in which a break has already been detected, and at least some of the steps of the method are repeated relative to said further zones; said structure is a cable comprising a plurality of substantially parallel metal strands; said structure is a main suspension cable of the suspension bridge and said first and second reference points delimiting the portion of the cable are situated at the hanger cable collars; the variation in the tensile or compressive force applied to the portion of the cable is obtained by loading the suspension bridge using a reference convoy.
The present invention also proposes a system designed to implement the aforementioned method. This system comprises means for detecting at least one variation in length within at least a portion of a structure, this portion being delimited by a first and a second point of reference of the structure and having a predetermined stiffness in the absence of breakage, in response to a variation in a tensile or compressive force applied to said portion, the variation in length detected by the detection means providing an indication as to whether or not there is a break within said portion of the structure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 , on which comment has already been passed, is a simplified diagram of a suspension bridge;
FIG. 2 depicts a portion of a “sound” cable;
FIG. 3 depicts a portion of a cable that has experienced a break;
FIG. 4 depicts a portion of a cable along the length of which a plurality of zones have been defined;
FIG. 5 is a graph showing variations in length for each of the zones of the cable portion of FIG. 4 ;
FIG. 6 depicts a system for detecting a break according to one embodiment of the invention;
FIGS. 7 and 8 show an operating principle of the system of FIG. 6 ;
FIG. 9 depicts a system for detecting a break according to the invention, applied to a portion of a cable that has experienced a break;
FIG. 10 depicts a system for detecting a break according to one embodiment of the invention and a graph of variations in length given by the system;
FIG. 11 depicts a system for detecting a break according to one embodiment of the invention and a graph of variations in angle given by the system;
FIG. 12 depicts a system for detecting a break according to one embodiment of the invention;
FIG. 13 depicts the detection system of FIG. 12 , in a view from above;
FIGS. 14 and 15 depict an angle measuring module used according to one embodiment of the invention;
FIG. 16 depicts a rotary element used in one embodiment of the invention;
FIG. 17 depicts a system for detecting a break and a plurality of graphs of variations in angle given by the system according to one embodiment of the invention;
FIG. 18 depicts a system for detecting a break and a plurality of graphs of variations in angle given by the system according to one embodiment of the invention;
FIG. 19 depicts a system for detecting a break according to one embodiment of the invention;
FIG. 20 depicts the detection system of FIG. 19 in a view from above;
FIG. 21 depicts a system for detecting a break and a plurality of graphs of variations in angle given by the system according to one embodiment of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 2 shows a length or portion 6 of cable to which the system and method according to the invention may be applied, it being understood that the invention may be applied to any kind of structure that has a predetermined stiffness, such as a girder, a slab, etc.
The cable of FIG. 1 is, for example, a suspension bridge main suspension cable consisting of substantially parallel (possibly twisted) metal strands. The portion 6 thus extends between two hanger cable collars 7 to which the hanger cables 8 are securely attached. It has a length L, a cross section S and an elastic modulus E. When the constituent strands of the cable are made of steel, the elastic modulus E is that of steel. It is therefore possible to calculate the stiffness K of the portion 6 , as if it were a spring, that is to say using:
K=E×S/L (1)
The portion 6 of cable is normally subject to a force F. When a variation in force ΔF arises in the cable, it therefore causes a variation in length ΔL of the portion 6 that is proportional to ΔF and inversely proportional to the stiffness K, namely:
ΔL=ΔF/K (2)
When one or more strands of the cable is or are broken within the portion 6 , this portion experiences a reduction in its cross section by the cross section corresponding to that of the broken strands, namely ΔS, in a zone surrounding the break point. As explained above, this break point is limited by internal friction between the strands. The portion can therefore be considered to behave like a plurality of springs in series, each one having a stiffness dependent on its cross section.
FIG. 3 illustrates this model. It shows a portion 12 of cable extending between two hanger cable collars 7 .
The overall length L of this portion is split between three successive zones 9 to 11 of respective lengths L 1 , L 2 and L 3 . The zone 10 is a break zone, that is to say the zone in which the strands of the cable have broken, which means that the cross section of the portion 12 is S−ΔS in this zone, as compared with S in the zones 9 and 11 not affected by the break.
According to formula (1), the stiffnesses in zones 9 to 11 are, respectively:
K 1 =E×S/L 1
K 2 =E ×( S−ΔS )/ L 2
K 3 =E×S/L 3 (3)
The total stiffness K′ of the portion 12 can therefore be written as a combination of these springs in series, giving:
1 /K′= 1 /K 1+1 /K 2+1 /K 3 (4)
This stiffness K′ is lower than that of an “sound” portion, that is to say one that does not have any break within it, such as the portion 6 in FIG. 2 .
As a result, an increase in the force in this portion 12 causes an elongation that is greater than it would be without this localized loss of cross section. This extra elongation is proportional to the increase in force and to the length of the portion affected by this loss.
Thus, detecting the increase in length ΔL′ of the portion 12 when subjected to an extra force ΔF may make it possible to conclude that there is a break within this portion. Knowing the value of the extra force ΔF and of the stiffness K of the portion when there is no break, makes it possible to verify that the elongation ΔL′ is greater than that ΔL of a sound portion, and therefore from this to deduce that there is a break within the portion 12 .
Although operation such as this enables a break to be detected within a portion of a cable, this detection may be considered to be insufficiently early in true-life applications, because the additional variation in the length of the portion becomes significant only when the cross section lost is relatively great, and so too the length of the break zone. The accuracy with which the variation in length of the portion is measured may be the limiting factor in this case.
FIG. 4 shows a portion 13 of cable along which a series of differential measurements is made, so as to obtain a better detection of breakage than was obtained in the previous case.
This portion 13 is divided into seven zones of respective lengths L 1 to L 7 . It is subjected to an initial tensile force F. As in the previous case, the force F can be increased by a value ΔF and a resulting variation in length detected for the various zones of the portion 13 .
FIG. 5 shows an example of values of the variation in length obtained for each of the seven zones of the portion 13 . The variations in length are advantageously expressed in relative terms, that is to say using the expression ΔLn/Ln, where n ranges from 1 to 7. It can be seen from FIG. 5 that the variation in length obtained for the length zone 3 of the portion 13 has the highest value. In accordance with that which was explained above, that means that the stiffness in this zone is lower than the stiffness in the other zones, which indicates a reduction in cross section as a result of a break in this zone.
As an alternative, rather than comparing the variations in length of all the defined zones directly against one another, the variation in length of each zone could be compared with the overall variation in length of the portion considered. It is then possible to determine what contribution each zones makes to the variation in length of the portion and from this to deduce whether or not there is a break in each of the zones considered.
This embodiment of the invention thus makes it possible to reach a conclusion as to the possible presence of breaks within a portion of cable. It also allows any breaks that might be present to be located with a certain degree of precision dependant on the number of zones defined along the length of the portion. Finally, comparing certain detected variations in length may, to a certain extent, make it possible to get around the problem of the precision of the measurement as mentioned in the context of the previous embodiment.
Another embodiment of the invention which further improves the reliability with which breaks can be detected and, if present, characterized, will be described hereinbelow.
FIG. 6 shows, straightened out to make it easier to understand, a portion 15 of cable delimited by points of reference which may, for example, be hanger cable collars 16 and 17 , in the case of a suspension bridge main suspension cable.
A pulley 20 is mounted rigidly on the hanger cable collar 16 via a rod 21 . This rod is preferably very rigid so that all the movements of the collar 16 are transferred in full to the pulley.
A wire 19 of constant cross section is anchored at its end 22 on an intermediate collar 18 and at its end 23 on the hanger cable collar 17 using a rod 24 . This rod 24 is also preferably very rigid so that any tensile force applied to the wire does not deform it. The wire 19 passes over the pulley 20 which can turn about its axle borne by the rod 21 . The wire 19 is, for example, stretched using devices situated at its ends 22 and 23 or alternatively by an antibacklash means belonging to the pulley 20 . There is no significant backlash between the pulley and its axle.
Thus, the wire 19 , of predetermined elasticity, is stretched partially over a zone of the portion 15 that extends between the intermediate collar 18 and the pulley 20 (strand 19 a ) and partly over the entire length of the portion 15 , that is to say between the pulley 20 and the hanger cable collar 17 (strand 19 b ).
As explained above, when the cable of FIG. 6 is subjected to an additional force ΔF, this causes a proportionate variation in length between the collars 16 and 17 . This elongation is passed on to the strand 19 b of the wire which reacts to it by exerting a tensile force on the pulley 20 that has a tendency to cause the pulley to turn. In the example illustrated in FIG. 6 , the pulley therefore has a tendency to turn in the clockwise direction when the additional force ΔF exerted on the cable is a tensile force.
However, since the collar 18 is firmly attached to the cable, it is liable to experience movement due to the elongation of the cable. This movement is dependent on its position within the portion 15 . Because the strand 19 a of the wire is connected to the intermediate collar 18 , it experiences an identical elongation which in reaction causes a tensile force to be exerted on the pulley 20 that tends to make the pulley turn in the opposite direction. In the example illustrated in FIG. 6 , the pulley therefore tends to turn in the anticlockwise direction when the additional force ΔF exerted on the cable is a tensile force.
The elastic modulus of the wire 19 is denoted Ef and its cross section is denoted s. l 1 denotes the length of the strand 19 b and l 2 denotes the length of the strand 19 a . Δl 1 denotes the elongation of the strand 19 b as a result of the relative movement of the collars 16 and 17 . Δl 2 denotes the elongation of the strand 19 a as a result of the relative movement of the collars 16 and 18 .
Because the elongations experienced by the strands of the wire are preferably transmitted in full by the collars to which they are attached, they are identical to those of the cable.
If f 1 denotes the force resulting from the elongation Δl 1 of the strand 19 b and f 2 denotes the force resulting from the elongation Δl 2 of the strand 19 a , then the following equations can be written:
f 1 =Ef×s/l 1 ×Δl 1, or alternatively f 1 =Ef×s×Δl 1/ l 1, and
f 2 =Ef×s/l 2 ×Δl 2, or alternatively f 2 =Ef×s×Δl 2 /l 2 (5)
The force differential between f 1 and f 2 causes the pulley 20 to rotate until these forces reach equilibrium, because this rotation in turn causes a change in length of the strands 19 a and 19 b of the wire 19 .
This phenomenon is illustrated in FIGS. 7 and 8 . FIG. 7 depicts the forces f 1 and f 2 exerted on the strands on the wire 19 on each side of the pulley 20 .
In the example depicted, the value of f 1 is greater than that of f 2 , thus creating a differential Δf able to cause the pulley 20 to rotate in the clockwise direction.
FIG. 8 shows the same device once the forces have reached equilibrium, that is to say once the forces f′ 1 and f′ 2 exerted on the strands of the wire 19 on each side of the pulley 20 are equal, so that the pulley 20 stops turning, the force differential now becoming zero. It will be noted that the differential Δf has caused the pulley 20 to rotate through an angle α, as illustrated in FIG. 8 . This angle α is proportional to the force differential Δf which is itself directly proportional to the relative elongations of the strands 19 a and 19 b , as shown by formulae (5).
Because the relative elongations of the strands 19 a and 19 b are properly transmitted by the collars of the cable to which collars they are attached, the angle α is therefore representative of the differential in relative elongation of the cable. In other words, the rotation of the pulley provides a reliable indication as to the relative variations in length of certain zones of the portion in question.
Thus, when the portion of cable is “sound”, that is to say when no metal strand of the portion of cable has broken, its relative elongation is constant along its entire length if the tensile force is varied. In particular, Δl 1 /l 1 =Δl 2 /l 2 . In this case, the pulley does not turn at all because, in accordance with formulae (5), the forces f 1 and f 2 are identical.
FIG. 9 shows the same system for detecting a break as was shown in FIG. 6 , applied to a portion of cable that has experienced a loss of cross section. This portion can be broken down into three parts 25 to 27 .
The intermediate zone 26 is the zone within which the break has occurred.
In the example illustrated in FIG. 9 , it will be understood from the foregoing that the strand 19 b undergoes greater relative elongation than the strand 19 a when the portion is subjected to an additional tensile force. This causes the pulley 20 to rotate in proportion with this imbalance. The final angle through which the pulley 20 rotates thus determines the relative elongation differential of the cable.
It will be noted that a tensile force exerted on the cable results in an elongation of the portion considered. Conversely, a compressive force may, on the other hand, result in the portion becoming shorter.
FIG. 10 shows a system for detecting a break applied to a portion of cable, similar to that of FIG. 9 , but in which system several intermediate collars 18 , 28 and 29 have been positioned along the length of the portion of cable, so as to obtain various measurements simultaneously or in succession.
Each intermediate collar defines a respective zone of the portion considered extending, for example, between the hanger cable collar 16 and the intermediate collar in question. Detecting any breaks that might be present will be performed relative to each of the zones thus defined.
According to that which was described above, a wire is stretched between an intermediate collar 18 , 28 or 29 and the hanger cable collar 17 , via the pulley 20 fixed to the suspension collar 16 . The force F exerted on the cable is then increased by the value ΔF, thus causing a relative elongation of the portion.
This then yields a relative variation in length Δli/li for each of the zones defined, where li denotes the length of the zone considered between the collar 16 and the corresponding intermediate collar. In the example illustrated in FIG. 10 , this then yields three length variation values each corresponding to one of the zones defined in relation to one of the intermediate collars 18 , 28 or 29 .
These measurements Δli/li may be plotted on a graph as depicted in FIG. 10 , as a function of li. Depending on the number of zones defined along the length of the portion of cable, that is to say on the number of intermediate collars used, it is thus possible to obtain a curve of greater or lesser precision charting the variations in length of the portion along the length of this portion.
The curve 32 depicted in FIG. 10 is one example of a curve thus obtained. It shows, in a portion 33 , a constant relative elongation that indicates that the geometric characteristics of the cable are unchanged in that portion and therefore that the stiffness of the corresponding part 25 of the portion is unchanged. In other words, the cross section of the part 25 of the portion of cable has not been corrupted, which indicates that no strands are broken in this zone.
A second portion 34 of the curve 32 corresponds to the part 26 of the portion of cable. This part 26 shows a change in cross section resulting from breakage of the cable, which manifests itself in an increase, for example a parabolic increase, in the curve in its portion 34 . The stiffness of the part 26 of the portion of cable is actually lower than that of the part 25 . The increase in the curve 32 is representative of the effect of the two parts 25 and 26 of the portion of cable of different stiffnesses placed in series.
A third portion 35 of the curve 32 corresponds to the part 27 of the portion of cable. In this portion 35 , the curve 32 decreases in for example a parabolic shape. This is representative of the effect of the three parts 25 to 27 of the portion of cable placed in series and of the fact that the cross section of the cable increases between the parts 26 and 27 of the portion, the part 27 not having been affected by the break.
The right-most value of the curve 32 corresponds to the variation in length Δl 1 /l 1 at the hanger cable collar 17 .
Simulation makes it possible to check that, in a typical exemplary embodiment, and once again adopting the notations L 1 , L 2 , L 3 , S and ΔS used above with reference to FIG. 3 , the various portions 33 - 35 of the curve 32 are of the following forms respectively: A, B+(A−B).L 1 /li and A+(B−A).L 2 /li, where A=ΔF/(E×S) and B=ΔF/(E×(S−ΔS)).
An analysis of the curve 32 therefore makes it possible to determine those zones of the portion of cable that have a break within them. A more detailed analysis of the curve, based in particular on values of the gradient or curvature of its various parts, also makes it possible precisely to determine the position of the break and the extent thereof. With prior knowledge of the additional force ΔF applied to the cable, it is possible to evaluate the cross section of cable lost as a result of the breakage of metal strands.
It will be noted that the curve 32 can be obtained using the break detection system described above, but that it may also be obtained using any measurement means able to determine the values Δli/li.
When the break detection system used is the one described above it may be advantageous, in practice, to construct a curve representing the angle of rotation α of the pulley as a function of length li. A curve such as this is depicted in FIG. 11 . It is dependent on the curve 32 depicted in FIG. 10 because of the relationship there is between the angle of rotation α of the pulley 10 and the force differential exerted on the two strands of the wire 19 . In particular, we again find three portions of curve 37 to 39 with different curvatures, underlying the series-effect of successive parts of the portion of cable of different stiffnesses. In particular, the portions 37 and 39 of this curve correspond to rotations of the pulley in opposite directions.
Simulation makes it possible to check that, in a typical exemplary embodiment, and again using the notations L, L 1 , L 2 , L 3 , S and ΔS used above with reference to FIGS. 2 and 3 , the various portions 37 - 39 of the curve 36 are, give or take a multiplicative factor, respectively of the following forms:
( L - li · f 1 ( li ) ) / ( 1 + f 1 ( li ) ) , ( L - li · f 2 ( li ) ) / ( 1 + f 2 ( li ) ) and
( L - li · f 3 ( li ) ) / ( 1 + f 3 ( li ) ) ,
where
f 1 ( li ) = L li + ( B - A ) · L 2 ( A + 1 ) · li , F 2 ( li ) = ( A + 1 ) · L + ( B - A ) · L 2 ( B + 1 ) · li + ( A - B ) · L 1
f 3 ( li ) = ( A + 1 ) · L + ( B - A ) · L 2 ( A + 1 ) · li + ( B - A ) · L 2
and where A=ΔF/(E×S) and B=ΔF/(E×(S−ΔS)). The multiplicative factor is the inverse of the radius of the pulley 10 . Thus, the smaller the radius of the pulley, the greater the sensitivity with which the angle α through which this pulley rotates can be measured.
The benefit of a curve of the type of curve 36 is that it can be plotted directly as the pulley rotation angle values are recorded, without additional calculation. Analysis of such a curve 36 can be performed in a similar way to analysis of the curve 32 described above. In particular, it makes it possible to reveal a zone of smaller cross section within the portion of cable considered and to assess the extent thereof. Analysis of the portions of this curve also allows the proportion of the cross section that has been lost to be determined, if the additional force applied to the cable is known.
A system such as this is also able to detect a number of changes in cross section along the portion, which then appear as a corresponding number of changes in gradient or curvature in the curves obtained.
In order for the data obtained to be fully exploitable, it is desirable for the additional force applied to the cable to be predetermined. One simple way of achieving this is, for example, to load up the construction of which the cable forms part, such as a suspension bridge, with a reference convoy the characteristics of which are known, having previously calculated the additional force in the portions of cable that result from the presence of this convoy. An operation such as this does not generally impose any constraint other than the temporary closing of the construction to traffic.
FIGS. 12 and 13 show, in a side view and in a view from above, respectively, a system for detecting breaks according to the invention as described above, in which system a number of intermediate collars 40 - 44 are positioned along the portion of cable considered, between the end collars 16 and 17 . Wires 45 - 49 are stretched respectively from each of these collars to a corresponding pulley P 1 -P 5 fixed to the collar 16 , and then as far as the opposite collar 17 . This set up allows length variation (or pulley rotation angle) values to be obtained simultaneously for each of the zones of the portion delimited by an intermediate collar. In this case, the construction need be loaded up by a reference convoy only once in order to obtain all the required data.
The wires such as the wires 19 and 45 - 49 in the figures commented on above may advantageously be pretensioned to a sufficient tension that the additional force exerted on the cable is immediately converted into an elongation of the strands. The measurement is sensitive right from the very onset of the phenomenon, as all “slack” is eliminated.
A force measurement device may be associated with the axle of each pulley and this would make it possible, on the one hand, to ensure that the wires were pretensioned, and, on the other hand, to make elongation measurements, the characteristics of the wires used being fully known.
It is also possible to add a force sensor to each of the strands on their tensioning device (at the points 22 and 23 in FIG. 6 for example) or elsewhere, in order to corroborate the pulley rotation angle measurement. This then improves the reliability with which breaks can be detected.
The rotation of the pulley may advantageously be measured using a rotary sensor firmly attached to the pulley axle. As an alternative, this measurement may be transferred to a linear displacement transducer the sensitivity of which can be increased using a lever arm. This last embodiment is illustrated in FIGS. 14 and 15 .
FIG. 14 thus shows a linear displacement transducer 52 mounted on the rotation axle 50 of the pulley 20 . This sensor is equipped with a moving finger 53 of linear travel that bears against a lever arm 51 fixed to the pulley along the diameter thereof. Before the extra force is exerted on the cable (not depicted) bearing the break detection system, the pulley 20 of the example depicted in FIG. 14 is in an initial position such that the lever arm 51 is vertical.
When an extra force is exerted on the cable, the movement of the wire 19 causes the pulley 20 to rotate, for example in the clockwise direction, through an angle α. The lever arm 51 therefore moves with the pulley in such a way that the finger 53 extends by a corresponding length d in order to remain in contact with the lever arm. This length d can be used to determine a relative variation in length at a zone of the portion of cable considered, in place or in addition to the measuring of the angle α.
FIG. 16 shows a rotary element that can be used in place of or in addition to the pulley 20 . It is an arm 54 able to rotate about an axle 55 . In this embodiment, the strands 19 a and 19 b of the wire used in the break detection system are each connected to one of the ends of the arm 54 so as to cause the arm to rotate about its axle as a function of the force exerted on each of these arms, under the effect of the elongation of the corresponding zones of the cable.
In one advantageous embodiment of the invention, use may be made of the progressive increase of the additional force ΔF applied to the cable, for example by the loading-up of the construction of which it forms part using a reference convoy. The variations in length of certain zones of the portion of cable considered (or alternatively the corresponding angle measurements) are then obtained at various stages in the loading operation.
This embodiment is illustrated in FIG. 17 where it can be seen that measurement points are obtained at successive instants, so that curves 56 - 59 can be plotted as the additional force ΔF progresses. Obtaining these various curves provides an amount of data able to make the analysis of the phenomenon, and therefore detection of any breaks there might be within the cable, even more reliable. Advantageously, attempts may be made to obtain measurements continuously during the force increase phase. Other data such as the position of the convoy, the temperature, etc., may also be obtained using sensors in order better to monitor and analyze the measurements.
FIG. 18 shows another advantageous embodiment of the invention in which a first curve of angle α or any other parameter representative of the variation in length of a zone of the portion of the cable considered is first of all obtained, for example using the break detection system of FIG. 17 . Next, having detected a break in a particular zone of the portion of the cable (the zone corresponding to the portion 61 of the first curve of FIG. 18 ), the break detection system is removed and re-fitted in such a way that it allows measurements to be taken in a more concentrated area around the detected break zone.
To do this, the intermediate collars are repositioned closer together around the detected break zone. This then provides further angle α values so that the first curve obtained can be refined in the relevant zone. It can thus be seen, in the example illustrated in FIG. 18 , that the refined curve has a portion 62 with a particularly notable decrease, indicating that a break has occurred in the corresponding zone of the cable.
Of course, other alternative forms may be derived from the general principles explained hereinabove and also form part of the present invention. In particular, other relevant parameters, in addition to or in place of the parameters Δli/li and α defined above may be used to detect variations in length within the cable in response to a variation in the tensile or compressive force applied to it. If necessary, it may then be possible to anticipate adapting the break detection system in order to measure such parameters.
FIGS. 19 and 20 show another example of a system according to another advantageous embodiment of the invention. Unlike the systems depicted with reference to FIGS. 12 and 13 , this system has just one wire, which runs between a network of a plurality of rotary elements such as pulleys P′ 1 to P′ 11 .
FIG. 21 shows a system similar to that of FIGS. 19 and 20 , mounted on a cable which has a break within it. During the loading test, the Δli/li discrepancies become amplified. A variation curve can then be plotted according to the principles explained above. When this curve shows a variation in the rotation angle α of at least some of the pulleys used (for example each of the pulleys P′ 1 , P′ 3 , P′ 5 , P′ 7 , P′ 9 and P′ 11 in order to obtain a measurement for each zone of the cable), it is then possible to detect from this a significant change in sign of gradient or curvature at the smaller cross section.
This change in sign of gradient or of curvature is advantageous, because it allows a particularly clear-cut detection of the break zone, as compared with a simple change in gradient or change in curvature, for example.
Other systems are of course also conceivable within the scope of the present invention. | The invention concerns a system for detecting a rupture inside a portion ( 6; 12; 13; 15 ) at least of one structure, delimited by a first ( 7; 16 ) and a second ( 7; 17 ) reference points of the structure, said portion having a predetermined stiffness in the absence of rupture and being subjected to a tensile or compressive stress (F). The method includes the following steps: detecting at least one length variation inside the portion of the structure, in response to a variation (?F) of the tensile or compressive stress applied to said portion; deducing from the detected variation length, the existence or not of a rupture inside said portion of the structure. | 6 |
This application is a continuation-in-part. Priority is claimed based on the disclosure in U.S. patent application Ser. No. 11/139,050, which will issue as U.S. Pat. No. 7,309,235 on Dec. 18, 2007; and which claimed priority based on the disclosure in U.S. patent application Ser. No. 10/035,104, filed Jan. 3, 2002, now abandoned, both of those applications having been filed by the inventor of the claimed process herein disclosed.
BACKGROUND OF THE INVENTION
Over many years, there have been various processes and equipment that make shoe laces, which typically are woven using cotton or synthetic yarns, or combinations of various types of yarns, in either a flat or round shape and have ends provided with tips, usually made of a suitable plastic, which prevent the shoe laces from unraveling and provide lace ends which are easy to insert through shoe eyelets or similar shoe lace arrangements. When it was needed to have shoe laces such as those shown and claimed in the inventor's soon-to-be-issued U.S. Pat. No. 7,309,235, it was found by the inventor that some of the foremost shoe lace manufacturers, located in the U.S. as well as in some foreign countries, did not know how to make them. She finally located two shoe lace manufacturers who somewhat reluctantly tried her process for her, and found that it worked extremely well.
SUMMARY OF THE INVENTION
The invention relates to one or more processes in which previously-unknown shoe lace structures, such as those shown in the above-cited application that is soon to issue as U.S. Pat. No. 7,309,235, are to be made, as well as other similar shoe laces that have the features of primary interest. Equipment to be used generally presently exists, but have not been previously used by employing the one or more processes set forth so as to successfully manufacture the subject shoe laces that are particularly constructed to help very young children learn how to tie their own shoe laces.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of the process embodying the invention herein disclosed and claimed.
FIG. 2 shows one of the shoe laces of a type disclosed in the inventor's earlier-filed U.S. patent application Ser. No. 11/139,050, which will issue as U.S. Pat. No. 7,309,235 on Dec. 18, 2007, which is one of the products of the process herein disclosed and claimed.
FIG. 3 is a cross-section view of the shoe lace shown in FIG. 2 taken in the direction of arrows 3 - 3 of that FIGURE.
FIG. 4 shows another of the shoe laces of a type disclosed in that same application, and which is also one of the products of the process herein disclosed and claimed.
DETAILED DESCRIPTION OF THE INVENTION
The various equipment used when employing the inventive process or processes herein disclosed and claimed includes most or all of the equipment devices set forth schematically in the drawing.
FIG. 1 shows all elements and steps that can be used in the inventive method very schematically, in blocks identified as to what the block represents. There is a control system 20 that has four successive actions on defined parts of the process herein disclosed and claimed. The first element or action of control system 20 is illustrated by block 22 , identified as “Dye Process Controls.” The directional arrow 24 shows that the Control System of block 22 acts in accordance with the direction and recipient indicated by that the head of arrow 24 .
The second element or action of control system 20 is illustrated by block 26 , identified as “Dryer Process Controls” and directional arrow 28 shows the continuity and order of the controlled steps that are identified in the control blocks such as indicated by that arrow 28 .
The third element or action of control system 20 is illustrated by block 30 , identified as “Cooling Controls”. Blocks 26 and 30 are connected by directional arrow 32 , indicating another function of the control system 20 as another or steps of the process takes place.
The fourth element of the Control System 20 is indicated by block 34 , which is identified as “Computer Information Input to The Loom and Beyond.” The directional arrow 36 connects the blocks 30 and 34 , with the controls of the loom being active to instruct the Loom Machine, the Tipping Machine, and the Inspection Station to be described.
Each yarn to be used is preferably raw yarn 40 that has not been dyed to color. In order to dye each yarn to a specific desire color, each yarn is placed on a spool 42 as indicated by arrow 48 . Spool 42 is preferably made of iron, for reasons set forth below. Such spools are commonly referred to as Iron Spools. Iron Spools of this type are well known. Spool 42 has many holes through which the colored dye can be received by the yarn on the spool. These holes also help all of the yarn 40 on the spool 42 to absorb the dye with which each yarn is to be colored, and particularly so when the spool is being rotated within the dye. While plastic spools can be used, they have a tendency to crack and break after only a few times being used. Therefore, the metallic spools are desirable for economic purposes and better functionality.
The one or more spools 42 containing raw yarn 40 that is to be dyed one particular color is immersed in a dye container 46 , as indicated by arrow 48 . The liquid dye 50 to be used has already been placed in the dye container 46 , as indicated by arrow 52 . Usually, the spool or spools are rotated to speed up the dying step. This rotation may also be sensed and data relative to that rotation, as well as date relating to conditions of the dye such as the dye temperature and the amount of dye remaining in the dye container 46 . At times its thickness relative to its viscosity can also be sensed, if that is something to be concerned about. It is to be understood that a number of separate spools are used for each yarn to be dyed a different color. These separate spools 54 , 56 , and 58 are shown schematically as, and identified as, a group in the schematic block 59 . They are schematically shown, by arrows 60 , 62 , and 64 , to be positioned in the Loom Machine 66 before that machine begins to process the various yarns into shoe laces. While three such spools are identified, it is to be understood that there may be more or less spools used within the Loom Machine 66 at any one time, depending upon the number of colors of yarn to be used in making the shoe laces. The range of colors is only limited by the numerous shades, tones and other characteristics of colors that one can imagine and desire to use. Since the yarns may be made of any of several types of yarn material, including, by way of example and not by way of limitation, polyester, cotton or other organic filaments that have been made into yarn, the process's dying time while located in other filled dye containers having different dye colors therein.
Each dyeing step is controlled by the ability of such yarns to accept the dye by absorption, and such controls are transmitted from the Control System's Dye Process Controls 22 to the Dye Container 46 by arrow 26 , and the information about the status of the dye in the Dye Container 46 is fed back to the Dye Process Controls 22 . Such information may include the temperature of the dye, the speed of rotation of the spool 42 , and sensors that sense certain characteristics of the dye itself.
The particular dye used for a particular color and brightness is chosen from a cache of dye formulas that may typically have as many as 1,000 or more possible different colors, categorized by shade, brightness and the dye or dye components used to make one particular dye, usually identified by color, at least generally. These dye formulas are typically kept on a computer, and often are considered to be trade secrets of the dye trade. Once a particular color having particular characteristics for the shoe lace that is to made, the dye 50 is precisely created from the ingredients required to make the desired color of the dye to be used.
For an explanation of the process herein disclosed and claimed, it is considered sufficient to diagrammatically disclose only one raw yarn 40 to be colored by a chosen dye 50 that produces the chosen dye color when the yarn 40 has been dyed and dried. At this time the yarn is no longer considered to be raw yarn.
When the shoe laces to be made are to be waterproofed, a water repellant 70 of a known type may be used together with the dye, or sometimes after the drying process is completed. It depends primarily on the particular waterproofing compound is to be used. The repellant is schematically shown to be placed in the Dye Container 46 by dashed line 68 . The dashed line represents the fact that the repellant is optional, and may be applied to yarn in another part of the process.
In one arrangement, the yarn is reeled off of the spool 42 and pulled through the particular dye that has been chosen and placed in the Dye Container 46 , as is illustrated by line 48 . The period of time that any one part of the yarn actually spends in the dye is determined by the Dye Process Controls 22 . This is accomplished by varying the speed at which the yarn is removed from the spool and then passes through the dye. In another arrangement the yarn, still on the spool, remains on the spool as the dying process is continued. After it has absorbed the dye, the now-dyed yarn, as indicated by line 74 , is hung up in loose skeins in preparation for the drying process, as indicated in block 72 .
The yarn, still in the form of skeins, is transferred to a drying station 76 , as indicated by line 78 , once its dying process has been completed. The yarn is then heated in the dryer by the use of heated air being blown through the yarn skeins, at a desired temperature which dries the dye and fixes the particular color in the yarn. If the waterproofing compound has been applied with the dye, it will also become fixed. The drying station is controlled by the Drying Process Controls 22 of the Control System 20 spools 54 , 56 , and 58 , shown as being in one block 59 in FIG. 1 , so that the yarn is dried at a temperature and for a set time depending upon the material of which the yarn is made, and the particular compounds in the dye used. By way of example but not of limitation, polyester yarn is dried at a temperature that is preferably between 110° and 130° Centigrade. Other yarn materials may have a different drying range.
After the desired temperature of a yarn forming loose skeins is reached and maintained for a set period of time, the yarn, still in the form of a skein, is then subjected to cooling air, as illustrated by the blocks 82 and 84 of the drawing. The cooling air is shown as being directed to the cooling step by arrow 86 . The air for cooling may be at normal atmospheric temperature. In extremely hot and humid atmospheres, however, the cooling air may be artificially cooled and dehumidified to the extent necessary to achieve a more normal atmospheric temperature such as about 27° Centigrade, and a relative humidity that is about 75% or less. The lower humidity will tend to decrease the actual time required to complete the cooling process, and a higher humidity will increase that time. The lower atmospheric temperature is used, with the understanding that it will also will have an increase in the humidity and that may decrease the drying time.
Once the yarns are dried, they may be either used in the Loom Machine 66 quite shortly, or are temporarily stored until they are later needed. If they are to be stored rather than being used immediately, the dried yarns are then transferred to a storage spool, which may be of iron, or a suitable hard plastic. This is noted in block 88 and by arrow 90 , of FIG. 1 . A storage spool that will serve as the spool for the loom machine 66 to be used can sometimes be used. If not, then the stored yarn on the storage spool has to be load onto the particular loom machine's spool, from which the yarn is taken for the chaining or weaving process performed in the loom machine. This is called “chaining” in that it is like a sewing chain stitch, where the yarn is transformed into a more finite form. There may be, and particularly for shoe laces, are, several chainings done in the making of one shoe lace.
In making the particular shoe laces of the type that is the subject of the above-noted U.S. application Ser. No. 11/159,050 and the about-to-be issued U.S. Pat. No. 7,309,235, the chaining operations form, from the yarns supplied to a loom machine on the spools holding yarns with all of the colors to be used in the finished product, a first tube within a second tube within a third tube, starting with the innermost tube being formed first. The outermost tube is the last tube formed. Of course, it is not a requirement that three, and only three, such tubes are made for each shoe lace, but that number of tubes making up the shoe lace seems to be the best for the special uses of these particular shoe laces, as noted in the referenced U.S. patent application Ser. No. 11/159,050. Depending to some extent on the particular yarn size being used, there can be a lesser number that three tubes, on a greater number of such tubes, in order to provide a sufficiently large shoe lace that youngsters can easily manage them with their fingers. One of the disclosed shoe laces to be made is made using two tubular parts. Part of the teaching the children to tie their own shoe laces is to increase their manual dexterity and sense of feel as well as their visual senses. These particular shoe laces may be round, but are preferably oval, as shown as one of the shoe lace types shown in the referenced U.S. patent application Ser. No. 11/159,050. The linear ridge that is a part of those oval shoe laces is formed as a part of the outside tube. The same is also true of the annular rings or ridges that are in linearly spaced relation on a shoe lace. This construction of some such shoe laces is also shown in that patent application.
The loom machine that is to be used for this is usually one of two types. One, and the preferred type, is known as a Jacquard loom or machine that is programmable to do braiding or circular weaving, because the three shoe lace tubes are braided or circularly woven while the chaining process is being carried out. Another type is known as a needle loom.
Both types have a long history, with the Jacquard type having a very early version. Joseph Marie Jacquard, was a French silk weaver and inventor. He invented the basic Jacquard loom mechanism in 1804-5. That first version was controlled by recorded patterns of holes in a string of cards, and allowed what is now known as the Jacquard weaving of intricate patterns. Later weavers were some of the inventors that improved on the machine's presentation of the concepts by Mr. Jacquard.
In the last few years there have been great strides in improving the Jacquard concepts. With many features that were not available until recent years, such as computers controlling the weaving of the intricate patterns as well as the finished physical features of such specialty woven items as shoe laces. Many of these modern machines were developed recently in China, Japan and Korea, although some were developed in other countries, including the United States. There are several manufacturers offering Jacquard machines and needle loom machines. Examples can be found by looking at Global Sources, found on the internet as “globalsources.com.” They include some made by Xiamen Ytai Industrial Co., Ltd. located at 11A Haiguang Building, Shuixian Road, Xiamen City, Fujian Province, China. More particularly, they have several different models of a “Computerized Jacquard Loom” that are available. Xiamen is only one of the companies that manufacture looms of various types for the trade. There also are numerous companies in the United States of America, Thailand and China that make shoe laces. They just do not make ones like the disclosure in the above-noted patent application, or similar shoe laces having the required features, and therefore do not practice the process of the invention herein disclosed and claimed.
Once the basic long length shoe lace stock, as in block 71 , of what will become shoe laces such as those shown in FIGS. 2 , 3 , and 4 , and other similar ones, are made, they are transferred, as shown by line 78 , and cut to length by the tipping machine as set forth in the drawing block 77 . The shoe laces then have their ends provided with the tips. Such tips are shown as a part of the shoe laces illustrated in FIGS. 2 and 4 . All this is preferably done with a tipping machine 77 . Several manufacturers throughout the world make or have made or used tipping machines, and virtually all shoe lace manufacturers use tipping machines that are automatic. Runs can be made for a specific shoe lace length, and the tipping machines can then be reset to run a different length or lengths when needed, using the input from the Control System through the connection shown by arrow 91 that is able to make such major changes in the operation of the tipping machine 77 .
Once tipped, each shoe lace passes through a quality control station, identified in the drawing as the Inspection Station 92 , where they are inspected for the proper length, and for the tips that have been properly placed and secured to the opposite ends of each shoe lace. All shoe laces that meet the requirements are then routed to an area, identified in the drawing by the block 94 as Acceptable Shoe Laces, where such shoe laces are placed. Any shoe laces that do not meet the requirements are routed to a different placement area, identified in the drawing by the block 96 as Rejected Shoe Laces.
The Jacquard machines or looms are preferred when the chain-weaving of the particular shoe laces is complex. The special shoe laces can alternatively be made on a needle loom using the herein disclosed and claimed process. The Jacquard machine takes less time to set up and run them than does to set up and run the needle looms.
The shoe lace 100 shown in FIG. 2 has a body 102 extending between the tips 104 and 106 that have been placed thereon in the tipping machine 77 . The oval cross-section shape of the shoe lace 100 is shown in FIG. 3 . The detailed description of these shoe laces are found in the above-cited U.S. patent application Ser. No. 11/139,050. The approximately half of the shoe lace body 102 , identified by the reference number 108 , is shown as having a contrasting color to the remainder of the shoe lace body, as are the small ridges 110 which are spaced at defined points on the other half 112 of the shoe lace body. In some arrangements, the part of the shoe lace body 108 , can also be a single small ridge relative to the other half 112 of the shoe lace body. Also, there is shown in FIG. 3 the oval shape of the shoe lace 100 , and the concentric arrangement of two tubes 114 and 116 that make up the shoe body. The outer tube is tube 116 . It has the small ridges 118 and 120 at the apogees of the body tube, as shown in FIG. 3 .
The somewhat different shoe lace 200 shown in FIG. 4 has much more definite annular ridges 206 , 208 and 210 . The ridges 118 and 120 shown in FIG. 3 may also be a part of the shoe lace 200 , but are not shown in this FIGURE.
The process herein disclosed and claimed may make shoe laces which have either one or both of the linear ridges shown in FIG. 3 extending along the entire length of shoe laces. Thus the process can be used to make some similar shoe laces that are not shown in the drawing, because the invention herein disclosed in FIG. 1 , and described in detail above, being a process, does not require that all shoe laces to be made by it be shown; so long at their manufacture comes within the invention claimed, such manufacture is still covered by the claims herein set forth. | The process includes steps for using raw yarn; dying the yarn; drying the dyed yarn by heating it; using the yarn in an appropriate loom machine such as a Jaquard loom or a needle loom to form concentrically-tubed shoe lace stock having a ridge on its outer tube; cutting the stock into desired shoe lace lengths; tipping the ends of the shoe lace lengths; inspecting the shoe laces; and placing the acceptable shoe laces in one area and the rejected shoe laces in another area. The objective of using the process is shown as variations of special shoe laces. | 3 |
FIELD OF THE INVENTION
[0001] The present invention relates to a novel strain of Lactobacillus amylovorus , which has antifungal properties and the ability to prolong the shelf-life of food products such as yeast or chemically leavened cereal products. Examples of baked products include but are not limited to breads and cakes, and intermediate products such as doughs, batters or sourdoughs. The invention also relates to the antifungal fermentation broth or extract of this strain as well as newly identified antifungal compounds produced by the strain.
BACKGROUND TO THE INVENTION
[0002] Bread is the most important staple food in the Western world and it is generally viewed as a perishable commodity, which is best consumed when ‘fresh’. The loss of perceived freshness is due to a number of factors, which may generally be categorised into one of two groups: those that are due to a series of complex processes collectively known as staling; and those that are attributed to microbial spoilage. Despite being studied for more than a century and a half, bread staling has not been eliminated and remains responsible for huge economic losses to both the baking industry and the consumer (Gray and Bemiller, 2003). The application of lactic acid bacteria (LAB) in the form of sourdough has been reported to have positive effects on wheat bread quality and staling (Corsetti et al., 2000; Clarke et al., 2002; Crowley et al., 2002).
[0003] The most frequent cause of microbial spoilage in bread is mould growth. Common spoilage fungi from bakery products belong to the genera Penicillium, Aspergillus, Monilia, Mucor, Endomyces, Cladosporium, Fusarium and Rhizopus (Legan, 1993; Poute and Tsen, 1987). In particular, Penicillium roqueforti is highly resistant to antifungal compounds, and it is responsible for about 70% of bread spoilage. In addition to the economic losses associated with spoilage of this nature, a further concern is the possibility that mycotoxins produced by the moulds may cause public health problems (Legan, 1993). A number of methods are applied to prevent or minimise microbial spoilage of bread, e.g. addition of propionic acid and its salts, modified atmosphere packaging, irradiation, pasteurisation of packaged bread (Legan, 1993; Pateras, 1998), or biopreservation (i.e. control of one organism by another). The recent years have experienced an increasing interest in the application of biopreservation in the food industry. In this regard, LAB are of special interest, since they have a long history of use in food and, in particular, lactobacilli are ‘generally regarded as safe’. Beside the weak organic acids, i.e. lactic and acetic acids (Röcken and Voysey, 1995; Röcken, 1996; Stiles, 1996), LAB produce a wide range of low molecular weight compounds (Niku-Paavola et al., 1999), peptides (Okkers et al., 1999) and proteins (Magnusson and Schniirer, 2001) with antifungal activity. Recently, the production of the antifungal cyclic dipeptides cyclo ( L -Phe- L -Pro) and cyclo ( L -Phe-trans-4-OH- L -Pro) has been shown for Lactobacillus plantarum MiLAB 393 (Ström et al., 2002). This strain was found to inhibit the growth of Aspergillus nidulans and to alter the fungal protein expression during co-cultivation studies (Ström et al., 2005). Cyclic dipeptides have been previously shown to be both antibacterial and antifungal (Graz et al., 1999) and it is likely that these substances, previously only reported from L. plantarum strains (Lindgren and Dobrogosz, 1990), are also produced by other LAB, e.g. Pediococcus pentosaceus and Lactobacillus sakei (Magnusson et al., 2003). Unfortunately, most of these investigations rely mainly on studies using laboratory media, which, even if suitable for testing activity, may however not reflect the situation encountered in a food system. Furthermore, during these studies some of the antifungal strains were found to lose their activity over time (Magnusson et al., 2003) Finally, the applicability of these antifungal strains as starters for fermentations has not always been considered nor has the quality of the final product been described.
[0004] Lactobacillus amylovorus has been noted as one of the dominant strains in type II sourdoughs and inhibitory substances produced by lactobacilli isolated from sourdoughs have been identified. The potential of selected lactic acid bacteria to produce food-compatible antifungal metabolites has been recorded. U.S. Pat. No. 6,827,952 describes Lactobacillus sanfranciscensis strains with mould-proofing activity and a method for producing bread. De Muynck et al. (2004) reported the isolation of 13 antifungal strains of LAB, one of which is recorded as Lactobacillus amylovorus . Corsetti et al. (2000) describe the addition of a L. amylovorus strain to sourdough and the positive effects of its amylolytic activity on bread firmness and staling. The delay of onset of fungal growth by 7 days in bread started with Saccharomyces cerevisiae and the sourdough isolate L. plantarum 21B has been reported. A notable property of antifungal activity demonstrable by bacterial strains is that it is often strain specific, affecting individual strains of target organisms and not others of the same species, thus providing a requirement for a number of producer strains in order to demonstrate a wide inhibitory spectrum. Other antifungal moieties (plant derived, essential oils, fatty acids, modified whey) are known but would not be suitable for use as starter cultures.
OBJECT OF THE INVENTION
[0005] The object of this invention is to isolate and characterise lactic acid bacteria with antifungal properties. A further object is to provide antifungal strains as starters for sourdough fermentation, and apply them in food preparation, more specifically in the production of bread and baked cereal products. Sourdough fermented by the antifungal L. amylovorus will be compared to sourdough fermented by traditional sourdough isolates, e.g. Lactobacillus plantarum and/or Lactobacillus sanfranciscensis , as well as to a chemically acidified dough and a non-acidified dough. Another object is to provide use of the strains to reduce staling of bread and baked cereal products. A still further object is to provide antifungal compounds responsible for the activity of the strains. Another object is to provide antifungal strains and extracts thereof for use in food preservation (e.g. for cereal, dairy, or meat products, as well as fruit and vegetables), as preservatives for animal feed production (e.g. silage), treatment of surfaces (e.g. wood) and pharmaceutical compositions for human and animal use (e.g. disinfectants, creams).
SUMMARY OF THE INVENTION
[0006] According to the present invention there is provided a strain of Lactobacillus amylovorus designated FST 2.11 as deposited under the accession no DSM 19280 on 13 th Apr. 2007 at the DSMZ (Deutsche Sammlung von Mikroorganismen and Zellkulturen), and strains substantially similar thereto also showing antifungal activity. The antifungal activity may be effective in bread, including low salt bread, and cereal products, and be capable of reducing staling of bread, including low salt bread, and cereal products. The strain of Lactobacillus amylovorus designated FST 2.11, and strains substantially similar thereto also encoding antifungal and bread antistaling properties, may find use as starter culture for food fermentation, e.g. bread, including low salt bread, cereal, dairy or meat products, preservation of fruit and vegetables, as a starter for the production of animal feed (e.g. silage), in the treatment of surfaces (e.g. wood), and in the production of pharmaceuticals for human and animal use (e.g. disinfectants, creams).
[0007] In another aspect, the invention provides the fermentation broth of the Lactobacillus amylovorus strain designated FST 2.11 and strains substantially similar thereto also encoding antifungal and bread antistaling properties, the supernatant of cultures thereof, or an extract of the strain, fermentation broth or supernatant. The fermentation broth, supernatant, or extracts may find use as food preservatives in the production of cereal, dairy or meat products, animal feed (e.g. silage), preservation of fruit and vegetables, treatment of surfaces (e.g. wood), and in the production of pharmaceuticals for human and animal use (e.g. disinfectants, creams). In a still further aspect the invention provides a method for the production of sourdough with antifungal activity comprising addition of the strain of Lactobacillus amylovorus designated FST 2.11 and strains substantially similar thereto also encoding antifungal and bread antistaling properties, the fermentation liquid of such strains or the supernatant thereof, or an extract of the strains or liquid to the sourdough starting materials.
[0008] Also provided are antifungal compounds active against bread spoilage organisms, including Penicillium roqueforti , produced by the strain Lactobacillus amylovorus FST 2.11 and strains substantially similar thereto also encoding antifungal and bread antistaling properties. The antifungal compounds find use in food production (cereal, dairy or meat as well as animal feed), as foodstuff ingredients/preservatives, as anti-microbial ingredients in pharmaceutical compositions, disinfectants, creams, wipes, lotions and ointments, edible packaging films or to decontaminate fruit, vegetables or surfaces generally.
[0009] In another aspect the invention provides use of one or more compounds selected from the group Cytidine, Deoxycytidine, Methylcinnamic acid, Cyclo(His-Pro), Cyclo(Pro-Pro), Cyclo(Met-Pro), or Cyclo(Tyr-Pro) as anti-fungal agents.
[0010] By substantially similar we mean strains, which are mutants or derivatives of the deposited strain, which also produce the antistaling and antifungal properties herein described. In another aspect the invention provides an antifungal agent active against spoilage moulds, comprising the strain of Lactobacillus amylovorus designated FST 2.11 or a strain substantially similar thereto also encoding antifungal and bread antistaling properties, the fermentation broth of such strains or the supernatant thereof, or an extract of the strains or broth.
[0011] A further method provided by the invention is the production of fermented cereal products or breads including low salt bread, comprising addition of the strain of Lactobacillus amylovorus designated FST 2.11 or a strain substantially similar thereto also encoding antifungal and bread antistaling properties, the fermentation broth of such strains or the supernatant thereof, or an extract of the strains or broth to the cereals or bread starting materials.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 . Partial 16S rDNA sequence of the strain of LAB designated FST 2.11. To determine the closest relatives of 16S rDNA sequences, a search of the GenBank DNA database was conducted by using the BLASTn algorithm.
[0013] FIG. 2 . HPLC profile of water soluble (A), 10% acetonitrile soluble (B) and 50% acetonitrile soluble(C) compounds produced by L. amylovorus FST 2.11. Compounds indicated with an arrow showed antifungal activity.
[0014] FIG. 3 . Microtiter well spore germination bioassay system used to identify antifungal compounds produced by L. amylovorus FST 2.11. The figure shows the compounds present in the 50% acetonitrile soluble fraction.
[0015] FIG. 4 . LAB cell counts (A), pH (B) and TTA (C) values of wheat sourdoughs fermented by L. amylovorus FST 2.11 (black dashed line), L. plantarum FST 1.7 (black line) or L. sanfranciscensis LTH 2581 (grey line) for 48 h at 30° C. LAB total cell counts were determined on mMRS4 agar.
[0016] FIG. 5 . Specific volume (A), moisture content (B), total volume of CO 2 (C), CO 2 released (D), and CO 2 retained (E), in wheat bread (CON), chemically acidified bread (CA) and sourdough bread fermented by L. plantarum (LP), L. sanfranciscensis (LS), or L. amylovorus (LA).
[0017] FIG. 6 . Hardness (A), rate of staling (B), and gumminess (C) of wheat bread (CON), bread containing a chemically acidified dough (CA) and sourdough wheat bread fermented by L. sanfranciscensis (LS), L. plantarum (LP) or L. amylovorus (LA) over 5 days of storage at room temperature.
[0018] FIG. 7 . Shelf life of wheat bread and wheat bread containing 20% sourdough fermented for 24 or 48 h. Bread slices were sprayed with about 10 4 spores of A. niger, F. culmorum, P. expansum or P. roqueforti , stored at room temperature and mould growth was monitored over 10 days.
[0019] FIG. 8 . Shelf life of lean bread containing 40% (20% flour replacement) sourdough inoculated with Lactobacillus amylovorous . Sourdough was prepared by using 50% wheat flour inoculated with Lactobacillus amylovorus FST 2.1 (10 5 CFU/g dough) and fermented at 30° C. for 48 h. Lean Bread: 5% Fresh yeast, 2% salt.
[0020] FIG. 9 . Shelf life of Japanese Rolls containing 40% (20% flour replacement) sourdough inoculated with Lactobacillus amylovorous . Soft'r Roll: 3% Fresh yeast, 1.5% salt and 6% sugar. Sourdough was prepared by using 50% wheat flour inoculated with Lactobacillus amylovorus FST 2.1 (10 5 CFU/g dough) and fermented at 30° C. for 48 h.
DETAILED DESCRIPTION OF THE INVENTION
Isolation and Identification of Sourdough LAB
[0021] Gluten-free sourdough was prepared according to a recipe recently developed at the UCC (Table I). Fermentation was performed either at 30° C. or 37° C. LAB from 24 h-fermented gluten-free sourdoughs were cultivated on mMRS5 (Meroth et al., 2003) agar supplemented with 0.05 g/l Bromcresol green and incubated at 30° C. for 48 h under anaerobic conditions. From the plates containing 30 to 300 colonies, 3 colonies per colony form were subcultured and identified by sequence analysis of the first 1000 base pairs (bp) of the 16S rDNA. To determine the closest relatives of the partial 16S rDNA sequences, a GenBank DNA database search was conducted. A similarity of >98% to 16S rDNA sequences of type strains was used as the criterion for identification.
Fungal Cultures and Preparation of the Spore Solution
[0022] The moulds Aspergillus fumigatus J9, Aspergillus niger FST 4.21, Fusarium culmorum FST 4.05, Fusarium graminearum FST 4.02, Penicillium expansum FST 4.22 as well as Penicillium roqueforti FST 4.11 were used as target organisms for assay of antifungal activity in vitro (Table II). Moulds were cultivated on malt extract agar (Oxoid, Hampshire, UK) and the fungal spore solutions were obtained as described previously (Magnusson and Schniirer, 2001). Briefly, A. niger, F. culmorum, P. expansum and P. roqueforti were grown on malt extract agar until sporulation occurred. Spores were harvested in physiological solution and stored at −80° C. in a glycerol/water (50:50 v/v) solution. Spores were transferred from this stock solution into a synthetic nutrient-poor medium (Nirenberg, 1976). Vigorous stirring (200 rpm) for 8 days at room temperature provided a fungal cell and conidial suspensions with a concentration of 5×10 7 spores ml −1 .
In Vitro Antimicrobial Activity
[0023] The inhibitory activity of L. amylovorus FST 2.11 against selected spoilage moulds and bacteria (see Table II for full list) was investigated using the overlay method (Magnusson and Schnürer, 2001) with some modifications. To avoid any pH effect, the screening was carried out on buffered mMRS5 agar plates. The medium was buffered to pH 6.5 using a 75 mmol KH 2 PO 4 solution. Lactobacillus plantarum FST 1.7 was included as a positive control, as the antifungal activity of this strain has been recently characterised (Dal Bello et al., 2007). Additionally, Lactobacillus sanfranciscensis LTH 2581 was used as a negative control. LAB strains were placed as cell spots on the plates and incubated at 30° C. for 48 h in anaerobic jars. To test antimicrobial activity against spoilage bacteria, plates were overlaid with 12 ml of standard I agar (Merck, Germany) containing 100 μl of an overnight spoilage bacterial culture. Plates were then incubated at 30 or 37° C. for 60 h. To investigate antifungal activity, a fungal spore solution (ca. 10 4 spores/ml) was sprayed by nebulisation on the surface of plates. Plates were then incubated at room temperature for 3 days. Inhibitory activity was scored as follows: −, no inhibition; +, very weak inhibition around the colonies; ++, low inhibition with little clear zones around the colonies; +++, strong inhibition with detectable zones around the colonies; ++++, very strong inhibition with large clear zones and nearly no growth around the colonies.
Isolation and Characterisation of Antifungal Compounds Produced by L. Amylovorus FST 2.11
[0024] Antifungal compounds of L. amylovorus FST 2.11 were isolated according to the method of Ström et al. (2002) with a number of modifications. Briefly, a microtiter well spore germination bioassay was utilised to determine the activity of compounds from culture filtrate against the indicator fungus A. fumigatus J9. Cell-free supernatant was fractioned on a C 18 solid phase extraction (SPE) column, allowing the separation of the hydrophilic phase from the hydrophobic phase. Prior to solid phase extraction a 10 ml sample of broth was taken and distilled with the distillate being examined for the presence of organic acids (up to 10 C— atoms). These acids were identified using comparative gas chromatography (GC) with mass spectroscopy (MS) with respect to elution time and molecular weight. All other compounds in the broth were separated using HPLC. To increase the ease of collection of compounds an initial separation was carried out with respect to elution time on the HPLC unit with the 99.8% MeCN phase being separated into 3 individual phases and evaluated separately. During separation all HPLC peaks corresponding to individual compounds were collected separately (no mass fractionating and bioassaying were performed) and once collected each compounds was either freeze dried or dried under a flow of clean dry nitrogen gas. Each compound was then evaluated for antimicrobial activity at a 50 mg/ml level using the spore germination bioassay described previously, with the level of outgrowth being examined both visually and also using a microtiter plate reader at a wave length of 490 nm. The chemical structure, molecular weight and fragmentation behaviour of compounds active in the bioassay were identified using 1 H nuclear magnetic resonance (NMR), LC-MS, and GC-MS. A Q TOF LC-MS was used to determine the molecular weights and fragmentation pattern of each compound (Table III), with these being compared to previously reported results. The collected 1 H NMR results were compared with previously reported NMR chemical shifts from a number of NMR databases. These results acted as a final confirmation of the molecule isolated.
Sourdough Fermentation and Analysis
[0025] The suitability of L. amylovorus FST 2.11 as starter for wheat sourdough fermentation was investigated and compared to that of traditional sourdough starters L. sanfranciscensis LTH 2851 and L. plantarum FST 1.7. Briefly, 80 ml of mMRS5 broth were inoculated (1% level) with an overnight culture and incubated for 24 h at 30° C. Cells were harvested by centrifugation at 4000 rpm for 10 min, washed twice and resuspended in 40 ml sterile tap water (containing ca. 5×10 9 CFU/ml). Six-hundred grams of wheat flour and 600 ml of sterile tap water (dough yield of 200) were mixed to homogeneity for 1 min with a Kenwood mixer mixed. The selected starter was inoculated at a final concentration of ca. 10 5 CFU/g dough. Sourdough fermentation was performed at 30° C. for 48 h. LAB cell growth during sourdough fermentation was investigated. Briefly, 1 g sourdough was serially diluted in sterile physiological solution and the LAB cell counts were determined on mMRS5 agar plates. At each time point, pH and TTA values were also measured using a suspension of sourdough (10 g), acetone (5 ml) and distilled water (95 ml) according to a standard method (Arbeitsgemeinschaft Getreideforschung e.V., 1994). To confirm the presence of the inoculated starter LAB, at the end of fermentation 3 colonies per colony form were picked from mMRS5 agar plates containing 30 to 300 colonies, purified and subjected to partial 16S rDNA sequencing according to a previously described method (Meroth et al., 2003).
Sourdough Bread Production
[0026] The sourdoughs fermented by the selected LAB were used for the production of wheat bread. Doughs were prepared by replacing 20% of the flour with an equivalent quantity of flour in the form of sourdough fermented by the selected strain. Dough formulations based on a flour quantity of 3000 g were mixed in a Stephan mixer (Stephan Sohne, Hameln, Germany) at level 2 (1400 rpm) for 20 s prior to scraping down and mixed for further 40 s. The doughs were rested in bulk for 30 min in the proofer (Koma BV Roermond, Holland) at 30° C. and 85% rh, scaled into 400 g portions, moulded in a small scale moulder (Machinefabriek Holtkamp BV, Almelo, Holland), placed in tins (180 mm×120 mm×60 mm, Sasa UK, Middx, UK) and proofed for 50 min at 30° C. and 85% rh. Baking was carried out at 230° C. for 30 min in a deck oven (MIWE, Arnstein, Germany). The oven was presteamed (300 ml of water) before loading and, on loading, was steamed by injecting 700 ml of water. The loaves were depanned and kept for 120 min on cooling racks at room temperature. Loaves were heat sealed in moisture impermeable bags (Polystyrol-Ethylene Vinyl Alcohol-Polyethylene) under modified atmosphere (60% N 2 and 40% CO 2 ) and stored at 21° C. Analyses were performed over a five-day storage period at three intervals: 2 h (after cooling and before packing), 50 h and 122 h, respectively. Additionally, a non-acidified dough as well as a chemically acidified dough were prepared. The chemically acidified dough contained a mixture of lactic and acetic acids (4:1 v/v) in order to yield a dough pH comparable to that of the doughs containing sourdough (biologically acidified).
Bread Analysis
[0027] A series of bread analysis were performed (in triplicate) prior to packaging. Loaf weight and volume (rapeseed displacement method) were determined. Bake loss and loaf specific volume (mug) were calculated. Crust and crumb colour were determined with a chroma-meter (Minolta CR-300, Osaka, Japan). For crumb texture analysis, loaves were sliced transversely using a slice regulator and bread knife to obtain uniform slices of 25 mm thickness. Two bread slices taken from the centre of each loaf were used. Images of the bread were captured using a flatbed scanner (HP ScanJet4c, Hewlett Packard) and supporting software (Desk Scan II, Hewlett Packard). The brightness levels were adjusted to 150 units and contrast to 170 units using software controls (Crowley et al., 2000). Texture profile analysis (TPA) was performed using a universal testing machine TA-XT21 (Stable Micro Systems, Surrey, UK) equipped with a 25-kg load cell and a 35 mm aluminium cylindrical probe. The settings used were a test speed of 2.0 mm/sec with a trigger force of 20 g to compress the middle of the breadcrumb to 60% of its original height. Water activity was determined with material taken from the centre of the crumb using the Aqua lab CX-2 (Decagon Devices Inc., Washington, USA). All measurements obtained with the three loaves from one batch were averaged into one value, i.e. one replicate. TPA was repeated with three loaves at day 2 (50 hr after baking) and day 5 (122 hr after baking).
Bread Challenge Tests
[0028] Sourdoughs were fermented for 24 or 48 h at 30° C. with the antifungal L. amylovorus FST 2.11 or L. plantarum FST 1.7, as well as with the control strain L. sanfranciscensis LTH 2581. Additionally, bread containing spontaneously fermented sourdough as well as a non-fermented bread and a chemically acidified bread were included. The antifungal activity of the LAB in the context of bread was determined using bread slices challenged against A. niger, F. culmorum, P. expansum as well as P. roqueforti spores according to previously described methods (Dal Bello et al., 2007). Briefly, the conidial solution (dilution 1:10) was applied by nebulisation on both sides of each slice at a rate of approximately 1 ml (ca. 10 4 spores) per bread slice. Each slice was then packed in a plastic bag and heat sealed, during which procedure a small slot was left open and a tip of a transfer pipette was inserted to ensure comparable aerobic conditions in each bag. Bags were incubated at room temperature and examined for mould growth during a ten-day storage period. A series of ten slices was inoculated. Mould growth was quantified as being the number of slice surfaces, i.e. both front and rear of slice, manifesting air mycelia.
Lean Bread and Japanese Rolls Shelf Life Tests
[0029] L. amylovorus FST 2.11 was investigated in form of sourdough for the potential to increase the shelf life of lean bread and Japanese rolls. For both experiments, L. amylovorus sourdough fermented for 48 h at 30° C. was added at 40% level (20% flour replacement), and the resulting bread/Japanese roll was challenged against contaminants present in an industrial bakery, including Penicillum aethiopicum and A. niger . Briefly, bread/rolls were exposed to the bakery air for about 10 min, packaged, stored at room temperature and mould growth was observed daily. The shelf life of bread containing 20% sourdough fermented by L. amylovorus was compared to that of standard bread (not containing sourdough) as well as bread containing 0.3% calcium propionate (maximum level allowed of chemical preservatives; calcium propionate is used as a preservative in a variety of products).
Results
Isolation of Sourdough LAB
[0030] Bacteriological culturing of spontaneously fermented sourdoughs revealed LAB cell counts of ca. 3×10 9 CFU/g sourdough. From the predominant LAB, isolates were subcultured. Analysis of the partial 16S rDNA identified the following species among the predominant LAB of gluten-free sourdoughs: L. amylovorus, Lactobacillus brevis, Lactobacillus johnsonii, L. plantarum, Lactobacillus reuteri, L. sanfranciscensis , and Weissella cibaria.
In Vitro Antimicrobial Activity
[0031] The sourdough LAB were tested in vitro for antimicrobial activity against A. fumigatus (data not shown). Among the different strains tested, one strain, i.e. L. amylovorus FST 2.11 (DSM 19280; see FIG. 1 for 16S rDNA homology results), was found to be highly inhibitory against A. fumigatus and was therefore selected for further investigations. The inhibitory spectrum of L. amylovorus FST 2.11 against several bacteria as well as fungi was investigated using an agar diffusion assay (Dal Bello et al., 2007). Results are summarised in Table II. The antifungal strain L. plantarum FST 1.7 (Dal Bello et al., 2007) was included in the screening together with the negative control L. sanfranciscensis LTH 2581. Most of the bacteria tested were inhibited by all selected LAB, however, only the strains L. amylovorus FST 2.11 and L. plantarum FST 1.7 inhibited the growth of common moulds in vitro. None of the tested LAB was able to inhibit the growth of P. roqueforti in vitro.
[0000] Antifungal Compounds Produced by L. amylovorus FST 2.11
[0032] Isolation of antifungal compounds produced by L. amylovorus FST 2.11 was performed using a spore germination bioassay. Both the hydrophilic and the hydrophobic phases were found to contain compounds showing strong inhibitory activity against spores of A. fumigatus (Table III). Compounds present in the hydrophilic and hydrophobic phases were separated using HPLC (see FIG. 2 as example). Overall, 27 antifungal compounds were isolated using the bioassay (see FIG. 3 as example), and 17 compounds were identified using NRMS, MS and GC (Table III).
Microbiological Analysis of Wheat Sourdoughs
[0033] LAB growths during wheat sourdough fermentation are shown in FIG. 4 . All the tested strains showed microbiological values (CFU, pH, TTA) typical of wheat sourdough fermentations (Meroth et al., 2003). For all the investigated sourdoughs, LAB cell counts of about 2-3×10 9 CFU/g sourdough were recovered. Identification of the isolates belonging to the predominant microbiota after 48 hrs of fermentation revealed that each of the strain persisted throughout the fermentation, thus indicating that the selected strains are suitable for wheat sourdough production.
Dough and Bread Analysis
[0034] The suitability of L. amylovorus FST 2.11 as starter for sourdough fermentation, and thus sourdough bread production, was evaluated using a series of tests, i.e. specific volume, moisture content, CO 2 produced/released, as well as hardness and rate of staling ( FIGS. 5 and 6 ). As controls, a chemically acidified dough as well as a non fermented dough were used. Taking into consideration all investigated parameters, the bread containing sourdough fermented by L. amylovorus FST 2.11 did not significantly differ from bread containing sourdough fermented by either L. plantarum FST 1.7 or the traditional sourdough-starter L. sanfranciscensis , thus clearly showing the suitability of strain DSM 19280 as starter for wheat sourdough production. All wheat sourdough breads showed improvement quality when compared to wheat bread or wheat bread produced using a chemically acidified dough. Addition of sourdough resulted in an increase in the specific volume of the bread ( FIG. 5A ), and thus of the bread volume and density, both being important parameters for consumer acceptability. Finding higher moisture content ( FIG. 5B ) in the control breads compared to the sourdough breads can also be explained by the biological acidification. During fermentation the drop in pH leads to increased enzyme activity as well as protein denaturation, and thus to a softening of the protein network. This in turn results in a higher release of water which can evaporate off during the baking process. Furthermore, proteolytic activity of the bacteria also leads to degradation of the protein network and thus to a higher loss of water during the baking process. The results concerning total, released and retained CO 2 are presented in FIGS. 5C , 5 D and 5 E, respectively. Overall, the addition of sourdough resulted in higher CO 2 production. This can be due to fermentation by heterofermentative LAB and/or by endogenous yeasts. Furthermore, the sugar and amino acids released by the bacteria can be easily used by the added yeasts, thus increasing the gas production. However, due to the biological acidification, most of the proteins have been degraded and the structure is weakened, as can be seen by the higher gas release of the sourdough samples when compared to the controls ( FIG. 5D ). This weakening of the structure is however masked by the increased amount of gas produced, as can be seen in FIG. 5E .
[0035] Analysis of the hardness and rate of staling revealed that addition of sourdough, independent from the inoculated strain, resulted in softer bread with a delayed rate of staling, when compared to the control breads ( FIGS. 6A and 6B ). The initial softening of the bread is a result of the sourdough enzymatic activity, which is responsible for the starch and protein breakdown. However, as we progress to day 2 and day 5 the hardness of the bread is dominated by the starch portion of the bread. FIG. 6C depicts the gumminess of the breads, which is a key parameter (mouth-feeling) for the consumer. Gumminess is perceived as a negative trait in bread. As shown, the addition of sourdough leads to a reduction in gumminess and so will improve consumer acceptability over the 5 days of storage. Again, L. amylovorus sourdough bread was not significantly different from L. sanfranciscensis sourdough bread, thus indicating that the addition of sourdough fermented by strain FST 2.11 leads to the positive effects that are traditionally associated with the use of sourdough.
Bread Challenge
[0036] In addition to the evaluation of its antimicrobial activity in vitro, L. amylovorus FST 2.11 was investigated in form of sourdough for the potential to increase the shelf life of wheat bread ( FIG. 7 ). L. amylovorus sourdough fermented for 24 or 48 h was added at 20% level, and the resulting bread was challenged with spores of A. niger, F. culmorum, P. expansum or P. roqueforti . Results were compared to those obtained using sourdough fermented by the antifungal L. plantarum FST 1.7, the non antifungal L. sanfranciscensis LTH 2581 or by the endogenous wheat flour biota (spontaneous fermentation). Twenty-four or 48 h fermented sourdough delayed the mould growth in a strain- and fungus-dependent manner ( FIG. 7 ). Overall, a retarded mould growth was observed when bread contained sourdough, but the addition of sourdough fermented by the antifungal strains resulted in a higher delay in mould growth. L. amylovorus FST 2.11 revealed to be by far the strongest antifungal strain, especially when 48 h fermented sourdough was used. Compared to the other investigated breads, addition of L. amylovorus fermented sourdough retarded up to 2 days the growth of A. niger , up to 7 days the growth of F. culmorum , and up to one day the spoilage of P. expansum or P. roqueforti . The same pH and TTA was measured in the two antifungal sourdoughs, i.e. sourdough fermented by L. amylovorus and sourdough fermented by L. plantarum . However, the increase in shelf life of wheat sourdough bread was significantly higher when fermentation was performed by L. amylovorus , thus indicating that strain FST 2.11 produces unique compounds which are responsible for this dramatic inhibition of mould growth.
[0037] L. amylovorus FST 2.11 was also investigated in form of sourdough for the potential to increase the shelf life of lean bread and Japanese rolls ( FIGS. 8 and 9 ). Results obtained from the Japanese rolls containing 20% sourdough fermented by L. amylovorus were compared with those of Japanese rolls containing 20% traditional sourdough, 1% vinegar, 0.5% Na-acetate, or no additives (standard rolls). The traditional sourdough was prepared with L. brevis ( FIG. 9 ). For both bread and Japanese rolls, a significant increase in the shelf life of products was obtained only when L. amylovorus sourdough was used. In particular, the presence of 20% sourdough fermented by L. amylovorus resulted in products with a longer shelf life than those containing maximum levels of chemical additives. Thus, L. amylovorus FST 2.11 revealed to be by far the strongest antifungal strain.
[0038] The words “comprises/comprising” and the words “having/including” when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.
[0039] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.
LITERATURE CITED
[0000]
1. Arbeitsgemeinschaft Getreideforschung e.V. (AGF), 1994. Standard-Methoden für Getreide, Mehl und Brot. 7. überarbeitete und erweiterte Auflage. 7th ed. Verlag Moritz Schafer: Detmold, Germany.
2. Clarke, C. I., Schober, T. J., Arendt, E. K., 2002. Cereal Chemistry 79, 640-647.
3. Corsetti, A., Gobbetti, M., De Marco, B., Balestrieri, F., Paoletti, F., Russi, L., Rossi, J., 2000. Journal of Agricultural Food Chemistry 48, 3044-3051.
4. Crowley, P., Schober, T. J., Clarke, C. I., Arendt, E. K., 2002. European Food Research and Technology 214, 489-496.
5. Dal Bello F., C. I. Clarke, L. A. M. Ryan, H. Ulmer, K. Ström, J. Sjögren, D. van Sinderen, J. Scharer, and E. K. Arendt. 2007. Journal of Cereal Science, 45: 309-318.
6. Gray, J. A., Bemiller, J. N., 2003. Comprehensive Reviews in Food Science and Food Safety 2, 1-21.
7. Graz, M., A. Hunt, H. Jamie, G. Grant, Milne, P., 1999. Pharmazie 54, 772-775.
8. Legan, J. D., 1993. International biodeterioration and biodegradation 32, 33-53.
9. Lindgren, S. E., Dobrogosz, W. J., 1990. FEMS Microbiology Reviews 87, 149-163.
10. Magnusson, J., Schürer, J., 2001. Applied and Environmental Microbiology 67, 1-5.
11. Magnusson, J., Ström, K, Roos, S., Sjögren, J., Scharer, J., 2003. FEMS Microbiology Letters 219, 129-135.
12. Meroth, C., Walter, J., Hertel, C., Brandt, M. J., Hammes, W. P., 2003. Applied and Environmental Microbiology 69, 475-482.
13. Niku-Paavola, M. L., Laitila, A., Mattila-Sandholm, T., Haikara, A., 1999. Applied Microbiology 86, 29-35.
14. Okkers, D. J., Dicks, L. M. T., Silvester, M., Joubert, J. J., Odendaal, H. J., 1999. Journal of Applied Microbiology 87, 726-734.
15. Pateras, I. M. C., 1998. Bread spoilage and staling. In: Technology of breadmaking S. P. Cauvain, and L. S. Young Eds. Blackie Academic and Professional: London, pp. 240-261.
16. Poute, J. G., Tsen, C. C., 1987. Bakery products. In: L. R. Beuchat (Ed.) Food and beverage mycology. 2 nd ed., AVI Van Nostrand Reinhold, NewYork, pp. 233-267.
17. Röcken, W., Voysey, P. A., 1995. Journal of Applied Bacteriology 79, 38S-48S.
18. Röcken, W., 1996. Advances in Food Science 18, 212-216.
19. Stiles, M. E., 1996. Antonie van Leeuwenhoek 70, 331-345.
20. Ström, K., Sjörgren, J., Broberg, A., Schnürer, J., 2002. Applied and Environmental Microbiology 68, 4322-4327.
21. Strom, K, Schnürer, J., Melin, P., 2005. FEMS Microbiology Letters 246, 119-24.
[0000]
TABLE I
Gluten-free sourdough composition.
Sourdough
Weight (grams)
Brown rice flour
200
Buckwheat (jade)
50
Soya flour
20
Potato starch
100
Water
370
[0000]
TABLE II
In vitro inhibitory activity of L. amylovorus DSM
19280 against common moulds and spoilage bacteria.
L.
L. sanfran-
L.
plantarum
ciscensis
amylovorus
FST 1.7
LTH 2581
FST 2.11
Bacteria
Bacillus subtilis FST 2.2
++
+
+
Citrobacter freundi FST 2.7
++++
+++
++
Enterococcus faecalis FST 2.8
+
+
++
Escherichia coli FST 2.3
+++
+++
+++
Listeria innocua FST 2.5
++++
++++
++
Micrococcus luteus FST 2.10
++++
+++
++
Proteus vulgaris FST 2.12
+++
++
++
Staphylococcus aureus FST 2.4
+++
++
++
S. aureus TMW 2.127
++++
+++
++
Moulds
Aspergillus niger FST 4.21
++
−
++
Fusarium graminearum FST
++
−
++
4.0122
F. graminearum TMW 4.0208
+++
+
++
F. culmorum TMW 4.0754
+++
−
++
Fusarium oxysporum FST 4.03
++
−
++
Penicillium roqueforti TMW
−
−
−
4.1599
[0000]
TABLE III
Antifungal compounds produced in vitro by L. amylovorus FST 2.11
showing strong inhibitory activity against A. fumigatus .
Increase in Shelf life
Chemical
Fragments
vs. control
Code
Compound
formula
MW
(MW)
(days)**
1
Glucuronic acid*
C 6 H 10 O 7
194.14
105.1, 91.1
>10
2
Cytidine*
C 9 H 13 N 3 O 5
243.22
109.1, 91.1
1
3
Deoxycytidine*,***
C 9 H 13 N 3 O 4
227.22
183.0, 93.1
1
4
Sodium decanoate*
C 10 H 19 O 2 Na
194.25
153.3, 103.0
>10
5
Hydrocinnamic acid*
C 9 H 10 O2
150.17
105.1
>10
6
Phenyllactic acid
C 9 H 10 O 3
166.17
149.0, 119.8
>10
7
OH— Phenyllactic acid*
C 9 H 10 O 4
182.17
163.1, 135.2
>10
8
Coumaric acid*
C 9 H 8 O 3
164.16
119.2
>10
9
Methylcinnamic acid*
C 10 H 10 O2
162.19
147.1, 117.1
>10
10
Salicylic acid*
C 7 H 6 O 3
136.12
93.2
>10
11
Cyclo(His - Pro)
C 11 H 14 N 4 O 2
234.26
207.1, 166.0,
2
110.1
12
Cyclo(Pro - Pro)
C 10 H 14 N 2 O 2
194.23
151.2, 70
4
13
Cyclo(Met - Pro)***
C 10 H 16 N 2 O 2 S
228.3
181.2,
3
14
Cyclo(Tyr - Pro)
C 14 H 16 N 2 O 3
260.3
233.0, 136.1
3
15
Cyclo(Leu - Pro)
C 11 H 18 N 2 O 2
210.13
183.2, 155.0,
3
86
16
Lactic acid
C 3 H 6 O 3
90.08
—
1
17
Acetic acid
C 2 H 4 O 2
60.05
—
1
*Electron spray ionization in the negative mode was used for MS/MS fragmentation of molecules on Q TOF and LCQ LC- MS
**50 mg/g of each compound and was evaluated over 12 days for the ability to stop the outgrowth of 10 4 /ml of A. fumigatus spores. Controls were spoiled after 2 days of growth
***Previously unreported antimicrobial compound | The current inventions relates to a strain of Lactobacillus amylovorus designated FST 2.11 as deposited under the accession no DSM 19280 on 13 Apr. 2007 in the DSMZ depository, and strains substantially similar thereto also encoding anti-fungal and bread antistaling properties and applications thereof. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a conversion from U.S. Provisional Application Ser. No. 60/097,694, filed Aug. 24, 1998, and relied upon for priority and a continuation in part of U.S. Ser. No. 09/212,042, filed Dec. 15, 1998, U.S. Pat. No. 6,148,935.
TECHNICAL FIELD
The invention relates to a method and apparatus for directional boring in rocky formations using an onboard sonde for controlling the direction of the bore.
BACKGROUND OF THE INVENTION
Directional boring apparatus or trenchless drills for making holes through soil are well known. The directional borer generally includes a series of drill rods joined end to end to form a drill string. The drill string is pushed or pulled though the soil by means of a powerful device such as a hydraulic cylinder. See McDonald et al. U.S. Pat. No. 4,694,913, Malzahn, U.S. Pat. Nos. 4,945,999 and 5,070,848, and Cherrington, U.S. Pat. No. 4,697,775 (U.S. Pat. No. RE 33,793). The drill string may be pushed and rotated at the same time as described in Dunn, U.S. Pat. No. 4,953,633 and Deken, et al., U.S. Pat. No. 5,242,026. A spade, bit or head having one or more angled faces configured for boring is disposed at the end of the drill string and may include an ejection nozzle for water or drilling mud to assist in boring.
In one known directional boring system, the drill bit is pushed through the soil without rotation in order to steer the tool by means of the angled face, which is typically a forwardly facing sloped surface. For rocky conditions, a row of teeth may be added to the drill bit and the bit operated in the manner described in Runquist et al. U.S. Pat. No. 5,778,991. Other toothed bits for directional boring through rock are shown in European Patent Applications Nos. EP 0 857 852 and EP 0 857 853, Cox U.S. Pat. No. 5,899,283, Skaggs U.S. Pat. No. 5,647,448 and Stephenson U.S. Pat. No. 5,799,740. Steering systems for use with these devices require keeping track of the angle of rotation of the sloped face of the bit and/or the teeth.
According to another known system, a transmitter or sonde mounted in a tubular housing is mounted behind and adjacent to the bit and sends a signal that indicates the angle of rotation of the bit. The sonde is mounted in a predetermined alignment relative to the steering portion of the bit. Since the sonde housing is generally made of steel, a series of longitudinal slots or windows are provided through the wall of the sonde housing to permit transmission of the signal. See generally Mercer U.S. Pat. Nos. 5,155,442, 5,337,002, 5,444,382 and 5,633,589, Hesse et al. U.S. Pat. No. 5,795,991, and Stangl et al. U.S. Pat. No. 4,907,658. Mounting of the sonde in its housing has been accomplished by end loading as illustrated by the foregoing patent to Stangl et al. or through a side opening which is closed by a door or cover during use, as illustrated in Lee et al. U.S. Pat. Nos. 5,148,880 and 5,253,721.
Prior attempts to use sondes in horizontal directional boring apparatus, particularly of the type for drilling consolidated rock formations, have proven less than ideal. Breakage of the sonde is to be avoided because sondes are difficult and expensive to replace. The sonde housing cover in side-loading sonde housings is prone to failure. The bolts used to secure the cover often loosen or break off as a result of the abrasion and stress applied to the sonde housing during boring, and the door or cover may work loose or collapse inwardly, crushing the sonde. A need remains for a more secure side-loading sonde housing which is nonetheless easy to open and close when necessary.
A need also persists for a directional boring system specifically adapted to horizontal boring through rocky formations, i.e., wherein the drilling head efficiently bores through consolidated rock formations which ordinary duckbill type bits are unable to penetrate. This can be particularly troublesome when mixed conditions are encountered during a bore, for example, the first portion of the bore is made through soft soil, but an unexpected rock formation is encountered. The connection between the bit and sonde housing should pass torque without undue strain, resist the unavoidable abrasion of surface metal that occurs during use, and yet readily permit disconnection, such as at the terminal end of a bore, at which point the drilling head (including both sonde housing and bit) is typically removed so that the drill string can be used to pull a pipeline back through the completed bore as it withdraws.
Threaded connections between the bit and the sonde housing are secure and shielded from abrasion, but difficult to disengage manually due to the high torque applied to the bit during operation. Bolts used to attach the bit to a sonde housing are exposed to abrasion and tend to loosen. It is also desirable to provide a bit which can be rebuilt and used several times, doubling or tripling the service life of the unit. The present invention addresses these concerns.
SUMMARY OF THE INVENTION
The present invention provides an improved apparatus for directional boring and in particular an improved system for boring through hard and rocky substrates frequently encountered when boring under obstacles such as roadways. According to one aspect of the invention, a directional drilling apparatus includes a drilling head having a front face angled relative to the lengthwise axis of the tool and configured for steering the drilling apparatus, a housing having an internal chamber for mounting an electronic locating device therein rearwardly of the drilling head for transmitting a signal indicating the orientation of the angled face of the drilling head, and a joint at which the drilling head is removably mounted to the housing of the locating device. The joint includes a splined connection for passing torque from the sonde housing to the bit and an interlock mechanism which mechanically secures the bit to the sonde housing in a manner permitting the bit to be manually removed from the housing without undue difficulty.
According to a preferred form of the invention, the interlock mechanism includes a projection, which may be the front end of the sonde housing or the rear end of the bit, and a socket into which the projection closely fits, which socket is formed on the other of the front end of the sonde housing or the rear end of the bit. The projection has a first opening having a lengthwise axis which lies in a plane substantially perpendicular to the axis of rotation of the drilling head, and a wall defining the socket has a second opening therein having a lengthwise axis which lies in a plane substantially perpendicular to the axis of rotation of the drilling head and which is brought into alignment (or near alignment, as described hereafter) with the first opening when the projection is fully inserted into the socket. A retainer is sized for insertion into the aligned openings. The retainer is preferably a pin or generally tubular insert that can be compressed from a relaxed state diameter to a retaining diameter at which an outer circumferential surface of the retainer tightly engages inner surfaces of the openings and holds the bit in engagement with the sonde housing.
The splined connection between the bit and the sonde housing preferably includes a series of longitudinal, spaced splines in one of the rear end of the bit or the front end of the sonde housing, and a corresponding series of longitudinal, spaced grooves in the other of the rear end of the bit or the front end of the sonde housing. Since the bit and housing must be keyed to one another so that the position of the sonde is in a known alignment relative to the cutting face of the bit, a master spline and groove are preferably provided so that the bit and sonde housing fit together in one predetermined alignment. As described hereafter, the splines may be provided on the outside of the projection, and the grooves may be provided on the inside of the socket.
According to a preferred form of the invention, the improved joint comprises a projection extending from a front end portion of the locating device housing, which projection has a series of longitudinal, spaced splines thereon. The projection has a longitudinal axis which is offset from a longitudinal axis of rotation of the drilling head. A rearwardly opening socket formed in the drilling head has longitudinal, spaced grooves configured to receive the splines of the projection therein. A keying mechanism, such as the master spline and groove combination described above, is provided on the projection and the socket to permit insertion of the projection into the socket only in one (or a limited number of) predetermined orientations. Openings in the socket and projection are configured to receive a removable retainer, such as a rolled pin, for mechanically interlocking the projection in the socket with the splines of the projection inserted into corresponding grooves of the socket. Such a joint according to the invention is protected from abrasion because of its location away from the outer periphery of the head, provides a strong connection due to the substantial length and width of the splines, yet can be taken apart easily by manually removing the retaining pins.
In another aspect, the invention provides a cutting head with a plurality of cutting teeth raked into the cut of the drilling head. Such teeth are oriented at an angle of at least about 30 degrees relative to an imaginary line normal to an arcuate front surface of the cutting head from which the cutting teeth project. Such an arrangement provides the desired shear cutting force against the rock face while simultaneously reducing the shock and vibration applied to sonde housing and the drill string. Preferred teeth for cutting rock according to the invention comprise a cylindrical base into which a carbide cutting tip is press-fitted or preferably brazed. These rock cutting teeth preferably have sufficient strength and width to survive and protect the tip from breaking away, plus sufficient length to project beyond the diameter of the brow, so that the teeth and not the body of the bit does the cutting. In a preferred embodiment, a small carbide rod can be inserted behind the tip to act as a back-up tooth when the carbide tip breaks away, as described further below. The cutting teeth are readily replaceable by tapping a used tooth out from behind using rearwardly opening tap-out holes provided for that purpose.
An improved drilling bit according to the invention may further incorporate a rear, frustoconical crushing surface that defines a space or zone crescent-shaped in cross-section that narrows from front to rear. The crescent-shaped crushing zone extends nearly 360 degrees and is configured for crushing rock fragments torn loose by the cutting teeth mounted on the front of the bit. The rear portion of the bit defining the crushing zone is free of large rounded projections that tend to cause loose stones and fragments in the crushing zone to bounce around, rather than be drawn into the narrowing end of the crescent for crushing.
The invention further includes an improved tooth for use on a rock drilling bit. Such a tooth includes a generally cylindrical tooth holder having a first frontwardly opening hole and a second frontwardly opening hole behind the first hole. A first cutting tip fits to a predetermined depth in the first hole. A second cutting tip fits to a predetermined depth in the second hole, such that the second cutting tip is positioned behind the first cutting tip. The second tip preferably is a separate piece from the first, and may have a smaller diameter than the first tooth such that it has a lower cost but is suitable for finishing a bore in progress when the first tooth breaks off.
In another aspect, the invention provides an apparatus for mounting an electronic device therein for use in an underground boring machine. Such an apparatus includes an elongated housing having means at opposite ends of the housing for connecting the housing to other components of the boring machine and an elongated internal chamber configured to receive an electronic device such as a sonde therein and having an elongated access opening which extends along an exterior surface of the housing. A cover sized to close the access opening has edges that fit beneath one or more flanges of the housing. A retainer such as a roll pin is sized for insertion into openings in the cover and housing, which openings become aligned when the cover is positioned with the edges beneath the flange of the housing. The retainer can be compressed from a relaxed state diameter to a retaining diameter at which an outer circumferential surface of the retainer tightly engages inner surfaces of the openings and holds the first part in engagement with the second part.
According to a preferred embodiment, the access opening has a recessed rim including a pair of elongated sides and a pair of ends spanning the sides, each side including a step on which the cover rests when its covers the access opening, and a pair of laterally inwardly extending rim flanges on opposite sides of the access opening each having a pair of inclined undersurfaces, which undersurfaces taper in a direction laterally inwardly and upwardly away from the step. The cover has a pair of laterally outwardly extending cover flanges on opposite side edges of the cover, which cover flanges taper in a direction laterally outwardly and downwardly so that the cover flanges mate slidingly with the undersurfaces of the rim flanges, whereby upon placement of the cover into engagement with the step in a first position wherein the cover flanges and the rim flanges are offset, the cover may then slide in a lengthwise direction so that the cover assumes a second position wherein the cover flanges underlie the rim flanges and at which second position the means for releasably securing the cover may be engaged.
An improved sonde housing according to the invention makes use of strategically positioned hard, wear-resistant studs to protect the body of the sonde housing from abrasion. Such studs have been previously used on cutting bits, but the benefits of using studs on the sonde housing have not been appreciated. In particular, placement of studs on the top face of the housing and optionally in a pair of annular formations near the front and rear ends of the housing improve the service life of the housing. In one aspect, a sonde housing configured for mounting a sonde therein comprises a cylindrical steel body have a sonde-receiving recess therein. A portion of the sonde housing body that receives a reaction force from a cutting bit has a series of hard, wear resistant studs mounted thereon effective to reduce wear on the portion of the sonde housing body that receives the reaction force. In another aspect, portions of the sonde housing body proximate opposite ends of the body have hard, wear resistant studs mounted thereon effective to reduce wear on end portions of the sonde housing body.
A further feature of the invention provides a coupling for a connecting two parts of a machine that rotates about an axis of rotation in use. Such a coupling comprises a first part of the machine that rotates in use, which first part has an first opening having a lengthwise axis which lies in a plane substantially perpendicular to the axis of rotation of the machine, a second part of the machine that rotates in use, which second part has a second opening therein having a lengthwise axis which lies in a plane substantially perpendicular to the axis of rotation of the machine and which is brought into alignment with the first opening when the first part is disposed next to the second part, and a retainer such as a roll pin which is sized for insertion into the aligned openings, wherein the retainer can be compressed from a greater relaxed state to a retaining diameter at which an outer circumferential surface of the retainer tightly engages inner surfaces of the openings and holds the first part in engagement with the second part. Such a coupling can maintain the two machine parts, such as a bit-sonde housing or sonde housing-starter rod, in mechanical engagement even without use of splines for passing torque. The recessed position of the resilient retainer during use shields it from surface abrasion, a common failure mode for bolts and other fasteners that must present an outwardly facing head. These and other aspects of the invention are described in detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, wherein like numerals denote like elements:
FIG. 1 is a bottom view of a drill head according to the invention;
FIG. 2 is a lengthwise sectional view of the drill head along the line 2 — 2 in FIG. 1;
FIG. 3 is a top plan view of the cover for the sonde housing shown in FIG. 2;
FIG. 4 is a side view of the cover of FIG. 3;
FIG. 5 is a right side end view of the cover of FIG. 3;
FIG. 6 is cross sectional view taken along the line 6 — 6 in FIG. 3;
FIG. 7 is a perspective view of the drill head of FIG. 1, with the sonde cover removed to show the sonde compartment;
FIG. 8 is a front view of the drill bit shown in FIG. 7;
FIG. 9 is a top view of the drill bit shown in FIG. 7;
FIG. 10 is a side view of the drill bit shown in FIG. 7;
FIG. 11 is an enlarged rear view of the drill bit shown in FIG. 7, with crushing action shown schematically;
FIG. 12 is a top view of the drill head shown in FIG. 1, with the sonde cover in place;
FIG. 13 is a cross sectional view taken along the line 13 — 13 in FIG. 12;
FIG. 14 is a cross sectional view taken along the line 14 — 14 in FIG. 12;
FIG. 15 is a cross sectional view taken along the line 15 — 15 in FIG. 12;
FIG. 16 is an enlarged cross sectional view taken along the line 16 — 16 in FIG. 12;
FIG. 17 is a front corner perspective view of the drill bit shown in FIG. 1;
FIG. 18 is a sectional view taken along the line 18 — 18 in FIG. 17;
FIG. 19 is a cross sectional view taken along the line 19 — 19 in FIG. 17;
FIG. 20 is a front center perspective view of the drill bit shown in FIG. 1;
FIG. 21 is a sectional view taken along the line 21 — 21 in FIG. 20;
FIG. 22 is a cross sectional view taken along the line 22 — 22 in FIG. 20;
FIG. 23 is a front corner perspective view of the front end of the sonde housing shown in FIG. 1, with the drill bit removed;
FIG. 24 is a view of the front end of the sonde housing as shown in FIG. 1, with the drill bit removed;
FIG. 25 is a side view, partly in phantom, of the drill bit body of the invention with teeth and carbides removed, with the original blank from which the bit body was machined shown in phantom lines; and
FIG. 26 is an enlarged, lengthwise sectional view of an improved cutting tooth according to the invention.
While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of contexts. The embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not limit the scope of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIGS. 1 to 7 , a drill head 30 according to the invention for use in a directional drilling apparatus includes a drill bit 31 removably mounted on the front end of a generally cylindrical sonde housing 32 . A rear end socket 33 of housing 32 is configured for connection to a corresponding projection forming part of a starter rod at the terminal end of a drill string. Details of this splined joint are described in U.S. Ser. No. 09/212,042 filed Dec. 15, 1998, the entire contents of which are incorporated by reference herein. The same splined joint may be used at the front end of sonde housing 32 as an alternative to the connection described hereafter. An internal flow passage 34 extends along the length of housing 32 from socket 33 to a front end face of housing 32 in order to conduct drilling mud or water to the bit, the use of which is well known in the art.
Sonde housing 32 has a lengthwise, laterally-opening sonde cavity 36 which is closed in use by a removable cover 37 . Cavity 36 has a centered, rearwardly-facing L-shaped key 38 which engages a corresponding groove in the end of the conventional cylindrical sonde to securely position the sonde in the cavity 36 in a predetermined alignment relative to the cutting teeth 67 of bit 31 as described hereafter. Since drill head 30 is generally made of steel, it is necessary to provide a series of spaced, thin longitudinal slots 35 in housing 32 and cover 37 to that the signal from the sonde can be detected from the ground surface.
Cover 37 includes two (or more) pairs of longitudinally extending wings 39 extending laterally from the lengthwise axis of cover 37 . Wings 39 matingly fit through lateral recesses 42 in a rim 43 of sonde housing 32 , and then cover 37 slides rearwardly in the embodiment shown so that wings 39 slide beneath adjoining portions of rim 43 into grooves 44 (see FIGS. 12-14.) It is preferred to provide at least two pairs of wings 39 at opposite ends of cover 37 in order to provide enhanced holding action. A third pair of wings and corresponding openings 42 may be located along the middle of cover 37 if desired. It is important that wings 39 have substantial length and thickness so that premature failure does not occur. Preferably, wings 39 extend at least about 10% of the total length of cover 37 , preferably from about 15% to 40% thereof, and have an outwardly tapering, dovetailed shape in cross section (FIGS. 6, 14 ) which matches an undercut profile of grooves 44 .
Cover 37 is typically made of steel but is nonetheless subject to severe torque during use. To prevent cover 37 from collapsing inwardly, it is best to support cover 37 along the entirely of its sides, rather than rely solely on lateral wings for support. Cavity 36 has a pair of longitudinal shelves 46 which are coplanar with each other and with a pair of end shelves 47 which lie beyond opposite ends of a sonde-receiving recess 48 . Shelves 46 , 47 provide the support needed to prevent inward collapse of cover 37 in all but the most extreme conditions.
To further protect the sonde as it rests in recess 48 , the ends of the sonde recess may be filled with a flowable compound such as a soft elastomer having a durometer in the range of about 10 to 20 on the Shore A scale. A urethane elastomer has proven most effective because it has a high chemical resistance to conventional drilling mud. After installation of the sonde onto key 38 , the flowable compound is poured in and set or cured to form a pair of resilient shock absorbers that conform to the space around the sonde and protect it from shocks and vibrations. The compound may be filled into the ends only, for example, to the dotted lines shown in FIG. 7, filling in front rounded, rearwardly facing recesses 45 A ahead of the sonde and rear rounded, frontwardly facing recesses 45 B behind to a level just slightly beyond and covering the front face of key 38 (e.g., 0.05 inch) and to the same level on rear sonde holding projection 49 . In the alternative, the compound can fill entirety of recess 48 , and in any case does not hinder transmission of the sonde signal or removal of the sonde when necessary. The surface of cover 37 should be free of studs, since this would place undue stress on the cover.
The use of bolts to secure cover 37 is of course feasible, but bolts tend to loosen or break off during use. Use of a bolt head to hold the cover down is not preferred because the head of the bolt, which creates the clamping force, is necessarily located on the outside of the device and little can be done to protect it from abrasion. Accordingly, as the fasteners used to removably secure cover 37 to housing 32 , it is preferred to use retainers 51 in the form of spiral-wound roll pins or a series of nested, split (C-) rings of the type which resiliently engage the walls of a mounting hole once inserted. Even a high-strength plastic rod, tubular or solid, could be used for retainer 51 . A preferred roll pin comprises a steel sheet having a thickness in the range of about {fraction (1/32)}-⅛ or {fraction (1/16)}-⅛ inch, a length of 2-4 inches, and a diameter in the range of about {fraction (7/16)} to ⅝ inch, more generally {fraction (7/16)} to 1 inch, and which has been spiral wound at least about one and one-half times, generally at least two times so as to provide a doubled thickness. It has been found surprisingly that such retainers remain in place in the rapidly spinning drill head even when no stop is provided in the direction of rotation, yet can be removed manually with a hammer and pin. This type of retainer is also used to connect the sonde housing 32 to the starter rod, as noted above, and to connect the bit 31 to housing 32 as described hereafter.
As illustrated in FIGS. 12 and 14, a pair of spaced, parallel, transverse holes 52 are provided in sonde housing 32 which open on the rear surface of housing 32 and on end shelves 47 thereof. Holes 52 preferably have axes slightly offset from a lengthwise axis A 1 of housing 32 and emerge at an acute angle relative to flat shelves 47 . Similarly, angled holes 54 in cover 37 align with holes 52 when cover 37 slides to its closed position, whereupon roll pins 51 are inserted to prevent cover 37 from sliding back to its original position until pins 51 are removed, such as by tapping them out from behind in the opposite direction from the direction of insertion. In the embodiment illustrated, roll pins 51 are confined for sliding movement between a pair of stops (annular steps) 56 , 57 provided in the walls of holes 52 , 54 , respectively. Pins 51 have a length slightly less than the length of the longer hole 52 , so that tapping with a chisel or rod from hole 54 drives pin 51 against step 57 to a position at which cover 37 can slide away, and tapping from the opposite side drives it against step 56 to a position as which cover 37 is locked from sliding. This arrangement is preferred in that pins 51 need never be completely removed and slide only a short distance between positions, making opening cover 37 much easier than with bolts.
Pins 51 and holes 52 , 54 are angled as shown in order to avoid passage 34 (see FIG. 14 ). Otherwise, since pins 51 do not provide a hold-down or clamping force on the cover as the standard bolts used in the prior art do, holes 52 , 54 could extend radially so that pins 51 would extend in a direction normal to the outer surface of cover 37 when installed. Mechanical engagement of wings 39 with corresponding inclined undersurfaces 50 of grooves 44 holds the cover down, and pins 51 act only to prevent cover 37 from sliding back in a lengthwise direction.
Referring to FIG. 7, carbide studs 68 are preferably deployed on sonde housing 32 in strategic locations to reduce wear on the base metal. In particular, a lengthwise row of studs 68 A is placed on the top surface of housing 32 opposite the primary cutting teeth 67 because reaction force from the teeth 67 tends to produce high wear in this area. Placement of studs along the periphery of rim 43 also reduces wear to cover 37 . It is also desirable to provide an annular formation of studs 68 B to protect the associated joint (splines) on the front end of housing 32 , and a further annular group of equiangular studs 68 C to provide similar protection for the rear joint connecting housing 32 to the starter rod.
Referring now to FIGS. 8-12 and 16 - 22 , drill bit 31 of the invention is illustrated in detail. Bit 31 preferably comprises a cut-away cylindrical body with a generally semi-cylindrical bottom section 61 , a flat, angled top face 62 which slopes forwardly and across the tool axis A 1 at an angle in the range from about 8 to 35 degrees relative to the tool axis A 1 (25° as shown), and a nose section 63 . Numerous rounded tungsten carbide studs 68 are distributed over the surface of bit 31 as shown. Carbides 68 serve a two-fold purpose of grinding cuttings passed back from the front of the bit 31 and protecting the surface bit 31 from excessive abrasion during use. Carbides are typically interference fitted into apertures 58 in head 30 , or may be brazed therein.
Face 62 can be used to steer head 30 through dirt by forward thrust without rotation in a manner known in the art, and when drilling in rocky conditions (forward thrust with rotation), can serve to guide the bit along a shelf as generally described in Runquist et al. U.S. Pat. No. 5,778,991, issued Jul. 14, 1998, and discussed further below. Face 62 has a pair of first and second central, forwardly flaring grooves 64 , 66 each of circular cross section (frustoconical) for channeling cuttings rearwardly from the head. First groove 64 is preferably deeper and flares more widely than second groove 66 , which is positioned such that cuttings are funneled to it by groove 64 .
Nose section 63 includes a radially extending, arc-shaped rim or flange 65 on which three large cutting teeth 67 A, 67 B, 67 C are mounted so that the cutting ends thereof extend outwardly beyond the outer diameter of the bit body. Nose section 63 has three large holes 71 A, 71 B, 71 C for receiving cutting teeth 67 . Holes 71 (i.e., 71 A-C, FIGS. 17-19) are evenly spaced in a generally semi-circular arc across along a front face 72 of rim 65 . Carbides 68 are distributed over front face 72 and especially on an outer face 80 to protect the metal and provide increased grinding action. Holes 71 are canted at an angle of from about 30° to 60° relative to an imaginary line normal to curved front face 72 in the direction of rotation of cutting head 30 . In one embodiment, the cutting teeth 67 are angled in the cutting direction at approximately 30°. The exact angle will depend in part on the slope of the conical end portions 21 of the cutting teeth, with a more tapered, sharper point requiring greater canting for the associated tooth 67 to provide the desired degree of shearing force to the formation being bored. A canting angle of less than about 30 degrees, especially 25 degrees or less, provides no significant improvement in cutting.
The cutting teeth of at least one prior art cutting head project straight from the cutting head, with the side teeth diverging slightly in opposite directions relative to the center tooth. In this configuration, the teeth of the prior art head produce a violent cutting action with the teeth bouncing onto and off of the rock being cut. It has been discovered that the resulting shock and vibration cause a higher rate of failure of the sonde and directional drilling machine. The smoother cutting action of the canted teeth 67 of the present invention reduces these problems.
Referring to FIGS. 19 and 26, teeth 67 of the invention are specially configured for extended life and replacability. Each tooth 67 has a generally cylindrical holder 70 with a front portion 73 which has a diameter great enough to securely mount a carbide tip 74 and a rear reduced diameter portion 76 which fits into hole 71 to a predetermined depth. Holder 70 is made of a conventional steel such as a 4140 alloy. Tips 74 are preferably cylindrical pellets made of a hard, wear resistant material which is not excessively brittle, e.g. high carbon tool steel, diamond, or a ceramic such as tungsten carbide. A tungsten carbide having a Rockwell hardness on the A scale of at least about 87 is preferred. An exposed front end face 79 of tip 74 is conical and more pointed than the generally hemispherical protruding portions of grinding buttons 68 . Relative to lengthwise tooth axis T, for example, conical front face 79 defines an included angle G in the range of 60° to 120°.
Rear portion 76 of tooth 67 has an outer circumferential groove 77 into which a C-spring retaining clip 78 is mounted. It is fairly common in use that tip 74 and the adjoining annular end of front portion 73 will break off, leaving only a stump of the tooth with little cutting capability. According to the invention, a secondary cylindrical recess 81 behind cylindrical recess 82 containing the base of tip 74 contains a further carbide cylindrical rod-shaped insert 83 , which is preferably separate from and of smaller diameter (e.g., 25%-75%) than tip 74 . When tip 74 finally breaks or wears off, insert 83 is provided to give the tooth enough cutting action to complete the bore then in progress.
When cutting teeth 67 are inserted into apertures 14 , the C-spring retaining clips expand into a shallow corresponding annular groove 75 (only about 0.015 inch) to secure cutting teeth 67 in position. As shown in FIGS. 18 and 19, tap-out holes 69 are provided as linear, reduced diameter extensions of holes 71 . When a tooth 67 must be replaced, it can be removed by insertion of a rod into hole 69 into contact with the back of tooth 67 , followed by tapping the rod with a hammer until tooth 67 loosens. FIGS. 17-19 illustrate the foregoing structures for middle tooth 67 B. Teeth 67 A and 67 C are configured in a like manner but at different positions as dictated by the geometry of bit 31 .
Referring to FIGS. 20-22, flange 72 of bit 31 also has a row of three fluid ejection ports 86 provided at spaced positions to provide optimum flushing action for teeth 67 . Typically the fluid is a drilling mud, for example, a mixture of water, polymer and clay. The drilling mud serves to lubricate and cool the cutting head 10 and to sweep rock chips and other bored material away from the cutting head during operation. Ports 86 receive fluid from associated angled passages 87 which meet at the inner end of rear recess 92 , described hereafter, and receive fluid from passage 34 (see FIG. 2 ). FIGS. 20-22 illustrate the foregoing structures for middle passage 86 . Side ports 86 are configured in a like manner but at different positions as dictated by the geometry of bit 31 . Ports 86 have a smaller diameter than conventional fluid injection outlets in order to achieve a higher velocity flow, and are positioned to the cutting side of each tooth 67 A,B,C to wash cuttings from each of teeth 67 .
A secure connection between bit 31 and sonde housing 32 must be provided. Typical bits or “duckbills” known in the art are bolted directly onto an angled face of the sonde housing. Since abrasion to the device occurs from the outside in, it would be more desirable to provide a connection that is partly or completely shielded from such wear, in contrast to bolts. Bolts also have relatively poor resistance to the high strain induced by drilling and often break during use.
Bit 31 is coupled to sonde housing 32 by means of a splined projection 91 provided on the front end of sonde housing 32 that fits into a corresponding rearwardly opening recess 92 in bit 31 . Recess 92 is eccentrically positioned relative to the central axis of the cutting head 10 . Such eccentric positioning of the coupling between the sonde housing and cutting head provides advantages in directional drilling as described hereafter.
Splines 93 are arranged in a radial circular formation on projection 91 in the manner of gear teeth. Splines 93 are preferably elongated in the lengthwise direction of sonde housing 32 to enhance the ability of the drill string and sonde housing 32 to pass torque to the bit 31 . Splines 93 are received in spline receiving grooves 94 in recess 92 as shown in FIG. 16. A widened master spline 93 A is received in a corresponding master groove 94 A, which are in turn in a predetermined alignment relative to key 38 so that bit 31 fits onto sonde housing 32 only in one predetermined orientation. This assures that the orientation of the sonde relative to teeth 67 is always correct. This contrasts with prior sonde housings mounted on bits by means of threaded connections, wherein slight over- or under-rotation of the bit relative to the sonde housing would cause the sonde signal to become out of alignment with the bit, leading to misdirected boring. Although, as illustrated, splined projection 91 is generally cylindrical, other geometries for splined projection 91 and recess 92 could be used. Likewise, it is within the scope of the invention to reverse parts described; in this case, the splined projection 91 would be part of bit 31 and fit into a corresponding recess in the sonde housing 32 . The splines may be relocated closer to the surface of the bit as described in the sonde housing-starter rod joint described in U.S. Ser. No. 09/212,042 filed Dec. 15, 1998, incorporated by reference herein.
Bit 31 includes a pair of parallel retainer (pin) receiving holes 96 which extend in a direction perpendicular to and laterally offset from the lengthwise axis A 1 of drill head 30 , as shown in FIGS. 11 and 16. Preferably a pair of such holes are positioned on opposite sides of axis Al, but even a single hole 96 could be used, depending on the anticipated drilling conditions. Holes 96 intersect corresponding outwardly opening semi-circular grooves 97 on opposite sides of projection 91 (see FIGS. 16, 23 , 24 .)
Once fully inserted, splined projection 91 is mechanically secured in recess 92 by pins 98 inserted into holes 96 . Steps 100 for preventing over-insertion may be provided near one end of each hole 96 . Pins 98 are inserted at the other end of each hole 96 and reach a fully inserted position when in contact with steps 100 . In one embodiment, the pins 98 are spiral-wound steel plates as described above for the sonde cover 37 that act in the manner of coil springs when inserted into holes 96 engaging the walls of holes 96 and grooves 97 and thereby remaining in place despite the violent movements of the head 31 during use. In operation, pins 98 are also disposed well within bit 31 and thus protected from surface abrasion.
Referring now to FIG. 16, grooves 97 each define an axis which is slightly skewed in a transverse (cross sectional) direction relative to the lengthwise axis of each hole 96 . As indicated by the lines L drawn along the bottom of each groove 97 , which are parallel to the axis of each groove 97 , there will be a slight interference fit as pins 98 are inserted, tending to push the splines in a counterclockwise direction as shown. In the embodiment shown, the angle is about 1° relative to the adjoining sidewall 99 of each hole 96 , and an angle of from half a degree up to about 2 degrees should be considered “slightly angled” for purposes of the invention. Insertion of pins 98 therefore preloads splines 93 in the driving direction against lead end walls 101 of the corresponding slots 94 . This prevents working of the joint during boring operation that would otherwise shorten the life of the connection.
When projection 91 is fully inserted and secured with pins 98 as shown in FIG. 2, clearance is provided so that the an inner, reduced diameter end portion of recess 92 forms a chamber 102 which distributes fluid from passage 34 to each of passages 87 . For this purpose, a front end of projection 91 ahead of the front ends of splines 93 has am outwardly opening circumferential groove 103 (FIG. 2) wherein an 0 -ring can be mounted to seal chamber 102 .
Cuttings from teeth 67 mix with the drilling mud injected from ports 86 and pass rearwardly along the outside of bit 31 under the pressure of the mud flow. Grooves 64 , 66 aid in passing a large portion of the cuttings back to a crushing surface 106 on the upper rear corner of the tool opposite nose portion 62 . Crushing surface 106 defines the outermost diameter of bit 31 on its top side as shown in FIG. 10, and is preferably studded with carbides 68 , optionally including a pair of central, enlarged carbides 60 (see FIG. 9 ). In general, flow from grooves 64 , 66 is directed toward crushing surface 106 . Surface 106 has a semi-circular shape (its width tapers rearwardly) and slopes forwardly as shown, so that pieces of rock that pass through are gradually pulverized as the space between the wall of the borehole and surface 106 decreases.
Referring now to FIG. 25, to provide the desired configuration for the crushing surface 106 , bit 31 is machined from a radially symmetrical blank 108 having a rear frustoconical portion 109 that increases in diameter in a rearward direction as illustrated, a central cylindrical portion 111 , and a front frustoconical portion 112 . The lengthwise axis A 1 of drill head 30 coincides with the longitudinal axis of blank 220 and recess 92 . A second axis A 2 is established at a location parallel to and radially offset from axis A 1 . A crescent-shaped portion of metal is removed based on a circle centered on A 2 , resulting in an exterior profile rearward of nose 63 that is a composite of arcuate surfaces based on the diameters of the circles based upon axes A 1 and A 2 . At its rear end, bit 31 has a circular cross section centered on axis A 2 and thus offset from tool axis Al. The axis of rotation of A 3 of head 30 is located at a point intermediate axes A 1 and A 2 , specifically along a line equidistant from lines tangent to the points defining the maximum outer diameter of bit 31 , namely a rear corner 114 at the end of crushing surface 106 , and a diametrically disposed outer face or rim 80 of nose 63 .
Bit 31 having the foregoing configuration provides an improved cutting action. Due to its eccentric positioning relative to the sonde housing and the smooth transition of its circular profile from back to front, bit 31 provides a crushing profile that is substantially arcuate (circular) along the entire cross-section of the borehole. As shown in FIG. 11, the resulting space between the inner surface 116 of the borehole and crushing surface 106 forms a crescent-shaped crushing zone 117 . A stone or fragment 120 caught in crushing zone 117 as bit 31 rotates is forced into a gradually narrowing end 119 of the crescent which coincides with surface 106 , and is thus more likely to be crushed than to bounce around inside crushing zone 117 . In this manner, drill bit 31 of the invention provides a more efficient crushing action.
Referring now to FIG. 25, to provide the desired configuration for the crushing surface 106 , bit 31 is machined from a radially symmetrical blank 108 having a rear frustoconical portion 109 that increases in diameter in a rearward direction as illustrated, a central cylindrical portion 111 , and a front frustoconical portion 112 . The lengthwise axis A 1 of drill head 30 coincides with the longitudinal axis of blank 108 and recess 92 . A second axis A 2 is established at a location parallel to and radially offset from axis A 1 . A crescent-shaped portion of metal is removed based on a circle centered on A 2 , resulting in an exterior profile rearward of nose 63 that is a composite of arcuate surfaces based on the diameters of the circles based upon axes A 1 and A 2 . At its rear end, bit 31 has a circular cross section centered on axis A 2 and thus offset from tool axis A 1 . The axis of rotation of A 3 of head 30 is located at a point intermediate axes A 1 and A 2 , specifically along a line equidistant from lines tangent to the points defining the maximum outer diameter of bit 31 , namely a rear corner 114 at the end of crushing surface 106 , and a diametrically disposed outer face or rim 80 of nose 63 .
In the above-described process, the apparatus of the invention can drill a borehole through a rocky substrate, which tunnel is curved or has several angled segments representing initial entry into the ground, horizontal boring under an obstacle such as a roadway, and upward travel towards the surface at the end of the borehole. Drill head 30 may also be used in the same manner as a convention duckbill-style bit to bore through soil or soft strata without drilling, but with reduced efficiency as compared to a boring head designed for normal push-and-turn directional boring through soil.
Other advantages of drill head 30 will be evident to those skilled in the art. Bit 31 is readily removable from sonde housing 32 by tapping out roll pins 98 from apertures 96 . This allows bit 31 to be readily replaced or rebuilt when worn. For purposes of rebuilding, the generally cylindrical shape of bit 31 gives it more mass and makes it far more re-usable than toothed duckbills (“bear claws”) known in the art and other bits which are essentially flat plates mounting teeth. Sonde housing 32 provides ready access to the sonde by means of cover 37 , which can be readily removed and replaced, yet has sufficient strength and support from beneath to resist crushing. Roll pins 98 preferably replace conventional bolts which are highly vulnerable to loosening and breakage. The rear end of sonde housing 32 is likewise secured by retainers such as roll pins insert though holes 121 forwardly of torque-passing splines 122 into corresponding holes in a projection of the starter rod at the front end of the drill string, as described in detail in the above cited U.S. Ser. No. 09/212,042 filed Dec. 15, 1998. This permits removal of head 30 at the receiving end of the bore and replacement with a back reamer to be pulled back through the hole with the directional boring machine.
While certain embodiments of the invention have been illustrated for the purposes of this disclosure, numerous changes in the method and apparatus of the invention presented herein may be made by those skilled in the art, such changes being embodied within the scope and spirit of the present invention as defined in the appended claims. | The invention provides an improved apparatus for directional boring and in particular an improved system for boring through hard and rocky substrates frequently encountered when boring under obstacles such as roadways. According to one aspect of the invention, a directional drilling apparatus includes a drilling head having a front face angled relative to the lengthwise axis of the tool and configured for steering the drilling apparatus, a housing having an internal chamber for mounting an electronic locating device therein rearwardly of the drilling head for transmitting a signal indicating the orientation of the angled face of the drilling head, and a joint at which the drilling head is removably mounted to the housing of the locating device. The joint includes a splined connection for passing torque from the sonde housing to the bit and an interlock mechanism which mechanically secures the bit to the sonde housing in a manner permitting the bit to be manually removed from the housing without undue difficulty. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application, a continuation-in-part utility patent application, claims priority to co-pending utility patent application Ser. No. 12/062,846, which was filed on Apr. 4, 2008, and to provisional application Ser. No. 60/910,250 filed Apr. 5, 2007 and to provisional application Ser. No. 60/998,984 filed Oct. 15, 2007, from which application Ser. No. 60/910,250 also claimed priority, and all three of which prior applications are herein incorporated by reference in their entireties.
GRANT REFERENCE
[0002] This invention was made with government support under Grant No. 68-3A75-4-137 awarded by USDA/NRCS and DOE. The Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
[0003] Agricultural combine harvesters are typically designed to cut off crops at ground-level, separate non-grain plant matter from the crop portions of the plant, save the crop portions to a holding tank or reservoir, and discard the non-grain plant matter at the rear of the vehicle.
[0004] Often, the non-grain plant matter, includes, without limitation, stems, cobs, stalks, leaves, and branches. The term crop residue may be used to describe this generally non-grain plant material. This term is indicative of the historical relative value of grain and non-grain material. The crop residue is chopped at the rear of the combine harvester and distributed over the ground where it is broken down by microbes in the soil and provides fertilizer for the next growing season's crops.
[0005] In recent years, however, there has been a growing movement to recover this non-grain plant matter and to use it for secondary processes, such as for a biomass material for ethanol production. Thus, this non-grain plant matter has value beyond its traditional usage. The collection of the material can either occur simultaneously with grain harvest in a single pass operation, or collected after grain harvest, in a multiple pass operation. In a single pass operation, the non-grain plant material can be collected after it is chopped at the rear of the vehicle and is directed into a “stover” cart or similar wheeled container that is towed behind the combine harvester to receive the non-grain plant matter, while the grain is collected in the combine grain tank. In a multi-pass operation, the non-grain material can be left on the field during grain harvest and collected during subsequent field operations, using a baler, forage harvester or similar machinery.
[0006] What is needed, therefore, is an apparatus for varying the amount of chopped non-grain plant material that is distributed over the ground while the vehicle is underway. What is also needed is a way of automatically varying the amount of chopped non-grain plant material that is deposited on the ground based upon soil parameters, crop parameters, terrain parameters or other environmental or regulatory factors.
[0007] It is an object of this invention to provide such an apparatus in at least one of the claims herein. Other embodiments and other inventions providing alternative or additional benefits are also be described herein.
BRIEF SUMMARY OF THE INVENTION
[0008] According to one aspect of the present invention, a crop residue harvesting system for a harvesting machine having a crop residue chopper is provided. The crop residue harvesting system includes an accelerator to assist in conveying crop residue and a transition member, the transition member having a first position and a second position. In a first position the transition member directs at least a portion of the crop residue to the accelerator for harvesting of the crop residue. In a second position the transition member allows for spreading at least a portion of the crop residue.
[0009] According to another aspect of the present invention, a harvesting machine is provided. The harvesting machine includes a self-propelled vehicle adapted for separating grain from crop residue, a residue chopper operatively connected to the vehicle and adapted for receiving the crop residue and chopping the crop residue to form chopped crop residue, an accelerator for conveying the chopped crop residue, and a transition member having a first position and a second position operatively connected between the residue chopper and the accelerator. In a first position the transition member directs at least a portion of the chopped crop residue to the accelerator for harvesting of the chopped crop residue. In a second position the transition member allows for spreading at least a portion of the chopped crop residue.
[0010] According to another aspect of the present invention, a method for harvesting a crop using a harvesting machine is provided. The method includes selecting a setting on the harvesting machine to control relative proportions of crop residue spreading and crop residue harvesting, separating grain from crop residue using the harvesting machine, collecting the grain using the harvesting machine, and chopping the crop residue using a chopper of the harvesting machine.
[0011] According to another aspect of the present invention, a harvesting machine is adapted for selectively collecting and spreading crop residue. The harvesting machine includes a vehicle adapted for separating grain from crop residue and a transition member having at least a first position and a second position. In a first position the transition member directs at least a portion of crop residue for collection. In a second position the transition member allows for spreading at least a portion of the chopped crop residue. There is at least one actuator operatively connected to the transition member for adjusting position of the transition member.
[0012] According to yet another aspect of the invention, a method of controlling the flow rate of crop residue deposited on the ground is provided in which a flow sensor disposed upstream of a crop residue outlet and a flow sensor disposed downstream of a crop residue outlet are coupled to an intelligent control to collectively indicate the flow rate of crop residue deposited on the ground.
[0013] The intelligent control is coupled to both the flow sensors in the embodiment. The intelligent control is configured to receive signals from both these sensors and to combine the signals to determine the crop flow rate pass out of the crop residue outlet.
[0014] The crop flow rate sensor disposed downstream of the crop residue outlet is disposed to sense the flow rate of crop residue that does not pass through the crop flow outlet. The crop flow rate sensor disposed downstream of the crop residue outlet is disposed to sense the flow of crop residue that is retained in the harvesting machine.
[0015] The crop flow rate sensor disposed upstream of the crop residue outlet is located in a position in which it is capable of sensing the combined flow of crop residue upstream of the crop residue outlet, which includes the combined flow of crop residue through the crop residue outlet and the flow of crop residue that is retained in the harvesting vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a perspective view of one embodiment of a harvesting machine in a crop residue collecting position.
[0017] FIG. 2 is a perspective view of the harvesting machine in a position such that crop residue is spread on the ground.
[0018] FIG. 3 is a side view of the harvesting machine for spreading and collecting crop residue in a single pass.
[0019] FIG. 4 illustrates the transition member for selecting between spreading and collecting in greater detail.
[0020] FIG. 5A illustrates another arrangement for the transition member.
[0021] FIG. 5B illustrates another arrangement for the transition member.
[0022] FIG. 5C illustrates yet another arrangement for the transition member.
[0023] FIG. 6 is a block diagram illustrating electronic control of the spreading and collecting of crop residue.
[0024] FIG. 7 illustrates placement of sensors on opposite ends of a chopper.
[0025] FIG. 8 is a block diagram illustrating the use and creation of map data.
[0026] FIG. 9 is a flow diagram illustrating collection and spreading of crop residue.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] The device combines two separate functions and can be switched to perform either of the functions at a given time. The transition/residue spreader can be set to either funnel crop residue from the outlet of the residue chopper at the back of a combine harvester to a blower for residue harvest purposes, or it can be set to deflect the residue away from the blower and uniformly distribute it on the ground. The transition component funnels the crop residue from the chopper to the blower being used for stover collection purposes. Thus, the flexibility of performing either operation is provided with minimal effort required to switch between the two. Moreover, the present invention provides for controlling relative amounts of crop residue which is collected and spread and this control may be provided electronically either by an operator or based on geographic position within a field or other factors such as, but not limited to, soil parameters such as soil moisture, soil pH, soil clay content, soil sand content; terrain parameters such as inclination of the field; and plant parameters such as the moisture content of the non-grain plant material, quality of material and the volume of the non-grain plant material, and other environmental or regulatory parameters such as residue removal rates for conservation compliance.
[0028] FIG. 1 is a perspective view of one embodiment of a harvesting machine in the form of a combine harvester 100 . The combine harvester 100 includes a self-propelled combine vehicle 102 , to which a harvesting head 104 is attached. The harvesting head 104 is supported on a feeder house 106 that is pivotally coupled to and disposed at the front of the vehicle 102 . A threshing system 108 is disposed within the vehicle 102 . The threshing system 108 feeds the threshed crop material to a cleaning and separating system 110 , which is also disposed within the vehicle 102 . Grain that is separated during cleaning and separating stages of the cleaning and separating system 110 , falls to the bottom of the combine harvester 100 and is conveyed by a grain elevator 112 to a grain tank 114 where it is held for future unloading such as to a grain cart (not shown) via unloading conveyor 116 .
[0029] Non-grain plant material, such as stems, stalks, leaves, branches, and cobs, is conveyed from the cleaning and separating system 110 to a chopper 118 disposed at the rear of the vehicle 102 . Chopper 118 may include a rotating shaft 120 to which a plurality of knife blades 122 are attached. Such blades preferably chop the non-grain plant material into lengths of about 1-2 inches or less.
[0030] The chopper 118 imparts considerable momentum to the chopped non-grain plant material, causing it to exit the chopper 118 into a transition member 124 . A transition member is a structure located anywhere between the chopper and the accelerator for selectively directing flow of crop residue between crop residue collecting and crop residue spreading. As shown in FIG. 1 , the transition member 124 includes a conduit 125 connected to the exit of chopper 118 . The conduit 125 extends between the chopper 118 and the accelerator 126 which may be disposed approximately 2 feet away from chopper 118 . The accelerator 126 includes a rotor that spins at high speed and conducts the chopped non-grain plant material up an exit conduit 128 which is coupled to the outlet of the accelerator 126 . The exit conduit 128 , in turn, directs the chopped non-grain plant material into a grain cart or other storage or transport container. FIG. 2 illustrates the combine harvester 100 of FIG. 1 except the transition member 124 is in a different relative position to affect the flow of crop residue from the chopper. As shown in FIG. 2 , the inlet end of the transition member is raised above the outlet from the chopper to direct the path of crop residue so that crop residue is spread on the ground and not directed towards the accelerator 126 .
[0031] FIG. 3 illustrates the combine harvester 100 with a stover cart 130 . The grain cart 130 may be drawn to the field by the combine 100 to which it is attached by a cart tongue 132 . Alternatively, the cart 130 may be drawn to the field by a tractor or other vehicle. In this manner, the combine harvester 100 may make a single pass of the field to collect grain in the grain tank 114 and crop residue in the cart 130 . In addition, because of the transition member 124 which may include a conduit 125 , some or all of the crop residue may be spread with the remaining portion collected through the control of the relative position of the transition member with respect to the chopper and/or the accelerator 126 .
[0032] Referring now to FIG. 4 , a detailed illustration is provided showing the chopper 118 , transition member 124 including a conduit 125 , accelerator 126 , and exit conduit 128 in partial cutaway. In FIG. 4 , the conduit 125 is illustrated in three different positions. The conduit 125 of the transition member 124 functions to direct the flow leaving chopper 118 proportionally into either (or both) of two directions: to exit conduit 128 and thence into wagon 130 . The space between the conduit 125 and the chopper outlet constitutes a crop residue outlet, since crop residue passing between the conduit 125 and the chopper outlet leaves the agricultural harvester entirely and is deposited on the ground.
[0033] A first position 200 is illustrated in FIG. 4 in which the conduit covers the entire outlet 202 of the chopper 118 , directing all chopped non-grain plant material exiting the chopper into the conduit 124 and thence into the accelerator 126 .
[0034] A second position 204 is also illustrated in FIG. 4 in which the conduit 124 partially covers the outlet 202 of the chopper 118 conducting a portion of the chopped non-grain plant material into the conduit 124 and directing the remaining portion of the chopped non-grain plant material against flow directors 206 that are coupled to the bottom of the conduit 124 and are disposed to direct chopped non-grain plant material into a wide swath that will cover the ground behind the combine harvester 100 , extending substantially all the way from the left side of the combine harvester 100 to the right side of the combine harvester 100 . In an alternative arrangement, flow directors 206 are disposed to direct chopped non-grain plant material into a wide swath that will cover the ground behind combine harvester 100 , extending substantially all the way from the left side of harvesting head 104 to the right side of harvesting head 104 .
[0035] A third position 208 of conduit 124 is further illustrated in FIG. 2 in which all of the non-grain chopped plant material leaving chopper 118 is directed into flow directors 206 . In this manner, all the chopped plant material leaving chopper 118 is distributed across the ground. By extension, none of the chopped non-grain plant material is directed into the open end of conduit 125 .
[0036] While only three positions are illustrated in FIG. 4 , conduit 125 can take any position between position 200 and position 208 . Thus, different relative amounts of crop residue may be spread or harvested.
[0037] In an alternative arrangement, shown in FIG. 5A , the transition member 124 includes a conduit 125 . The inlet end of the conduit 125 is pivotally coupled to the outlet 202 of chopper 118 . The outlet end of conduit 125 is movable up and down to the same range of positions shown in FIG. 4 with respect to the inlet of accelerator 126 . In this embodiment, flow directors 206 are disposed adjacent to accelerator 126 , and are not disposed on conduit 125 . The space between the outlet end of conduit 125 and the inlet of accelerator 126 constitutes a crop residue outlet, since crop residue passing between the conduit 125 and the chopper outlet leaves the agricultural harvester entirely and is spread on the ground.
[0038] In another alternative arrangement, shown in FIG. 5B , the accelerator 126 is movable with respect to chopper 118 to a range of positions in which 100% of the chopped non-grain plant material is directed into accelerator 126 and 100% of the chopped non-grain plant material is directed into flow director 206 and all positions in between as in the previous examples. In this arrangement, the transition member 124 includes the inlet conduit to the accelerator 126 .
[0039] In a further alternative arrangement shown in FIG. 5C , a portion 210 of the floor of conduit 124 is pivotable up-and-down through a similar range of positions to direct 100% of the chopped non-grain plant material into accelerator 126 or 100% of the chopped non-grain plant material into flow director 206 and all positions in between as in the previous examples. In this arrangement, the transition member 124 includes the outlet conduit from the chopper 128 .
[0040] Other alternative arrangements for the transition member are contemplated. For example, the transition member may be placed after the accelerator. Thus, the transition member need not be positioned between the chopper and the accelerator as shown.
[0041] In each of the foregoing examples, an actuator 212 is provided to move the movable complement to its range of positions in order to provide for the direction of flow either through accelerator 126 or over the ground. Actuator 212 as shown here is a hydraulic cylinder having one end connected to a rigid support and a second end connected to the element that is moved to change the direction of flow of chopped non-grain plant material. Thus, in the arrangements shown, the actuator 212 is operatively connected to the transition member 124 to change paths of crop residue from the chopper 118 .
[0042] Actuator 212 need not be a hydraulic cylinder, however. It may be a linear actuator that is hydraulically, pneumatically, or electrically driven. It may be rotary actuator that is hydraulically, pneumatically, or electrically driven. Other types of actuators may be used as appropriate in a particular application or environment.
[0043] In one arrangement, the operator has a control in the operator's cab 214 ( FIG. 3 ) that is operable while the vehicle is underway to reposition the actuator and redirect flow either through accelerator 126 or over the ground. In another arrangement, one or more sensors are provided that sense soil conditions, terrain conditions, or crop conditions and automatically reposition the actuator according to an algorithm stored in an electronic memory of an intelligent control such as a microcontroller, processor, or other type of intelligent control. In another arrangement, a map is provided to, either alone, or in combination with the above identified sensors, be used to automatically reposition the actuator 212 according to an algorithm stored in an electronic memory of a microcontroller.
[0044] FIG. 6 illustrates several of these arrangements in schematic diagram form. Referring now to FIG. 6 , an intelligent control 400 is electrically connected to an actuator 212 which may control a hydraulic valve to change the relative position of the transition member. In this way, the intelligent control 400 controls the relative amounts of crop residue spread and collected. The intelligent control can be based on instructions within memory 414 , such as instructions formed based on a map. The intelligent control may also be based on signals from various sensors as well as operator input devices.
[0045] Intelligent control 400 is coupled to the terrain sensor 406 which is responsive to the slope of the ground over which combine harvester 100 is traveling. As the slope changes, terrain sensor 406 sends a signal indicative of the slope of the ground to the intelligent control 400 , which receives the signal and adjusts the position of actuator 212 accordingly. In particular, as terrain sensor 406 senses the changing slope, the intelligent control 400 is configured to adjust actuator 212 to increase the amount of chopped non-grain plant material that is distributed over the ground, thereby providing heavier ground cover on portions of the field with greater slope. This additional ground cover retains rain and slows run off thereby reducing soil erosion.
[0046] Intelligent control 400 is also coupled to soil sensor 408 which senses the soil surface residue. As surface residue decreases, the intelligent control 400 is configured to adjust actuator 212 to increase the amount of chopped non-grain plant material that is distributed over the ground. In this case, it is assumed that the objective is to maintain place surface plant residue above a certain threshold for conservation management compliance.
[0047] The intelligent control 400 is also coupled to soil sensor 410 which senses the organic matter content of the soil. As organic matter increases, the intelligent control 400 is configured to decrease the amount of chopped non-grain plant material that is distributed over the ground. The assumption is that if soil organic matter levels are high greater material removal rates are possible without effecting soil quality. This will allow higher removal rates and increased economic returns.
[0048] The intelligent control 400 is also coupled to an electronic position sensor 412 such as a GPS receiver, LORAN receiver, or other ground, satellite-based, or dead reckoning position sensor. The intelligent control 400 is electrically connected to a memory 414 which may be internal and/or external and which stores map data of the field through which combine harvester 100 is traveling and harvesting crop. For each possible harvester position in the field this map indicates a desired position of actuator 212 necessary to deposit an appropriate amount of chopped non-grain plant material on the ground. In one configuration, this map data is derived from one or more soil conditions, such as the amount of nitrogen, phosphorus, or other trace elements in the soil, soil acidity, and amounts of previous herbicide, pesticide, or fertilizer applications. The plant material removal rates may be dictated by any one of these agronomic parameters.
[0049] The intelligent control 400 is also coupled to one or more crop sensors 416 which are disposed in combine harvester 100 in a flow path of the cut crop to determine characteristics of the cut crop material.
[0050] In one arrangement, a crop sensor 416 is a moisture sensor. The intelligent control 400 is configured to control actuator 212 to vary the amount of chopped non-grain crop material that is deposited on the ground as the crop moisture changes.
[0051] In another arrangement a crop sensor 416 is a material quality sensor, such as ethanol conversion potential. The intelligent control 400 is configured to control actuator 212 to increase the amount of chopped non-grain plant material that is deposited on the ground as the crop stover quality decreases.
[0052] In another arrangement an operator input device 420 is coupled to the intelligent control 400 to permit the operator to select the type of crop being harvested, such as wheat or corn. The intelligent control 400 is configured to control actuator 212 to vary the amount of chopped non-grain plant material that is deposited on the ground based upon the type of crop that is being harvested.
[0053] The intelligent control 400 is also coupled to a material flow rate sensor 418 . Depending on the fullness of the crop growth that it harvests, the amount of non-grain plant material may vary significantly. This may require that the system adjusts to the changing flow rate of non-grain plant material by adjusting actuator 212 to maintain constant the amount of non-grain plant material distributed over the ground.
[0054] For example, in a parched portion of the field the plants being harvested may be stunted and produce very little non-grain plant material for sending through chopper 118 . This will not change the volume of air that is conveyed through chopper 118 and accelerator 126 , but it will reduce the density of chopped non-grain plant material entrained in the air—the material flow rate of chopped non-grain plant material through conduit 125 , and thus the amount of material deposited on the ground.
[0055] To maintain constant the amount of material distributed on the ground, the intelligent control 400 is configured to monitor the mass flow rate of non-grain plant material passing through combine harvester 100 and to control actuator 212 to maintain the material flow rate at the appropriate material flow rate.
[0056] For example, the intelligent control 400 is configured to continually determine an appropriate material flow rate to be deposited on the ground based upon the changing signals received from one or all of sensors 406 , 408 , 412 , 416 , 418 and the location of the vehicle indicated by map data stored in the memory 414 . As the combine harvester travels through the field, the appropriate material flow rate will change. The intelligent control 400 correspondingly changes the position of actuator 212 to maintain this appropriate material flow rate. Similarly, the intelligent control 400 senses when there is a change in the amount of the material entrained in the air and corrects for this as well to maintain the appropriate material flow rate.
[0057] The material flow sensor 418 may be disposed in the flow path of the non-grain plant material upstream of chopper 118 . It may also be disposed in a flow path downstream of chopper 118 . Referring now to FIG. 7 , placement of several different material flow rate sensors is shown. They are identified in FIG. 7 as sensors 418 A, 418 B, 418 C, and 418 D.
[0058] Material flow rate sensors 418 A is an optical flow rate sensor which is configured to transmit light between the two sensor elements across a flow path disposed upstream of the inlet of chopper 118 .
[0059] An identical optical flow rate sensor may be alternatively disposed downstream of the outlet of chopper 118 . It is shown in FIG. 5 as sensor 418 B.
[0060] Material flow rate sensor 418 C is a mass impact flow rate sensor responsive to the impact of non-grain plant material against a striker plate. The greater the material flow rate, the greater the material impacts against sensor 418 C, and the greater the signal generated by sensor 418 C.
[0061] An identical mass impact sensor may be disposed downstream of the outlet of the chopper. It is shown in FIG. 5 as material flow rate sensor 418 D. Of course, additional sensors and types of sensors and alternative placements may be used to assist in sensing data which may be used to control the relative amounts of crop residue spread and collected. Additional sensors of any number of types may be placed throughout the combine in any number of locations or configurations to assist in sensing information or data useful in the control or monitoring of the performance of the combine, characterization of grain or grain movement, characterization of non-grain material or non-grain material movement, or for other purposes.
[0062] All of the flow rate sensors shown in FIG. 7 are disposed around the chopper or downstream of the chopper. They are all located upstream of the transition member. The flow rate signals generated by the various flow rate sensors of FIG. 7 therefore indicate the flow rate of crop residue before it is divided into a flow that is spread on the ground and a flow that is ultimately deposited in a collection container variously described as a stover cart 130 , grain cart 130 , cart 130 or wagon 130 .
[0063] In an alternative arrangement shown in FIGS. 4 , 5 A, 5 B, and 5 C, any one or more of the flow rate sensors 418 , 418 A, 418 B, 418 C, and 418 D (shown collectively in FIGS. 4 , 5 A, 5 B, 5 C as item “ 418 ” for simplicity of illustration) may be disposed downstream of the crop residue outlet to sense the flow rate of the flow of amount of crop residue that has not exited the harvesting machine. The signals from these downstream flow rate sensors as shown in FIG. 6 are provided to the intelligent control.
[0064] The intelligent control, in turn, is alternatively programmed to calculate the difference between the flow rates indicated by one or more of the flow rate sensors 418 , 418 A, 418 B, 418 C, 418 D illustrated in FIG. 7 that are disposed upstream of the crop residue outlet and the flow rates indicated by one or more flow rate sensor or sensors 418 of FIGS. 4 , 5 A, 5 B, 5 C that are located downstream of the crop residue outlet.
[0065] This difference is equivalent to the flow rate of crop residue passing through the crop residue outlet and being spread onto the ground. The difference provides a more accurate measure of the amount of crop residue that is deposited on the ground and in a preferred arrangement is used by the intelligent control as electronic feedback to maintain the amount of crop residue distributed upon the ground at a desired amount, e.g. the amount indicated by the prescription map data 450 for each location in the field.
[0066] FIG. 8 is a block diagram illustrating information flow. As shown in FIG. 8 , prescription map data 450 may be used to provide the intelligent control 400 with instructions regarding control of the spreading and collecting of crop residue. The intelligent control 400 then provides for controlling the spreading and collecting of crop residue at least partially based on the prescription map data 450 . The intelligent control 400 may save data regarding its control of the spreading and collecting of crop residue to generate residue map data 452 . The residue map data 452 may be the same or different from the prescription map data 452 as prescribed operations may be over-ridden by operator control, or based on feedback from various sensors.
[0067] FIG. 9 is a flow diagram illustrating movement of residue within the harvesting machine such as a combine harvester. In step 930 , grain is separated from residue. The grain may be collected in a conventional manner. In step 932 , the residue is chopped with a residue chopper. The residue chopper may be of any type or design, including but not limited to a flail chopper. In step 934 alternative paths for the residue are provided depending upon the current configuration or setting. The configuration may be modified in various ways such as by changing position of a lever or electronic control. If the configuration is set to spread residue then in step 936 the residue is spread. Alternatively, if the configuration is set to collect residue then in step 938 residue is directed towards an accelerator. In step 940 , the residue is collected. In step 934 , the position or setting may direct different amounts or proportions of crop residue towards the accelerator and to be spread. There are any number of positions which allow for varying amounts of crop residue to be spread and collected, thus varying amounts of crop residue may be spread while varying amounts of crop residue are collected during a single pass harvesting operation.
[0068] A combination residue spreader and collector for single pass harvesting systems has now been disclosed. It is to be understood that the present invention is not to be limited to the specific embodiments described here as variations in size, form, structure, and features are contemplated. These and other variations, options, and alternatives are within the spirit and scope of the invention. | A harvesting machine, a method for harvesting using the harvesting machine, a crop residue harvesting system for the harvesting machine, and an apparatus are provided. The arrangement described herein spreads crop residue over the ground. It uses sensors to monitor the amount of crop residue spread over the ground. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Divisional Application of U.S. patent application Ser. No. 10/376,462, filed Feb. 28, 2003 now U.S. Pat. No. 6,988,320.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method of using a water or spirit level composed of an elongated body, preferably of metal, at least one bubble mounted in the elongated body, and end caps, preferably of plastics material, at the end faces of the elongated body, wherein at least one outer surface of the elongated body constitutes a preferred measuring surface.
2. Description of the Related Art
Levels have been for decades manufactured all over the world in large numbers and are used regularly primarily in civil engineering. For reasons of strength and dimensional stability, the body of a level is usually composed of metal, in most cases light metal, and conventionally has a rectangular hollow cross section or a I-shaped solid cross section. In order to prevent damage to the levels in case of impacts or when dropped, the level body is provided with end caps which are composed of a relatively soft, elastic, shock-absorbing material, usually plastics material. When the level body is of a hollow section, the end caps also serve as closures.
A level with an end cap of plastics material is disclosed, for example, in AT 398 846 B. This level has a level body with an I-shaped cross section. The cross section of the end caps is rectangular and their dimensions are adapted to the dimensions of the level body. For fastening the end caps to the level body, the end faces of the level body are provided with two blind-end openings which have several undercuts. The end caps are provided with appropriate lugs which engage positively in the blind-end openings. In this manner, the end caps are inseparably fastened to the level body.
In the manufacture of levels, there is the tendency to construct the shock absorbers at the end caps larger and larger in order to achieve a better protection against damage. However, end caps which are manufactured as injection molded articles have manufacturing tolerances and also have a different coefficient of expansion than the level body. In order to prevent the end caps from projecting beyond the measuring surfaces of the level, the end caps are manufactured with smaller cross sectional dimensions than the level bodies; in addition, also for aesthetic reasons, the end caps are frequently slightly outwardly conically beveled. The smaller cross sectional dimensions result in an undesirable step in the plane of the measuring surface in the joining area between the end cap and the level body.
This has the result that, for example, in the corner area of two walls where a line or marking has to be transferred from one wall to the other, the line or marking cannot be continued precisely around the corner because the measuring surface of the level cannot be placed all the way into the corner because of the presence of the end cap mounted on the end face of the level body. The greater the length of the portion with no line or marking, the more effective the shock absorption of the end cap. This results in inaccuracies.
Many artisans solve this problem by pulling off the end cap by applying great force. However, since the end caps are not designed for such a use, they find no support when they are once again inserted into the level body; rather, the end caps remain separate and become lost. This is not satisfactory.
SUMMARY OF THE INVENTION
Therefore, it is the primary object of the present invention to provide a method of using a level which makes it possible to continue lines or markings precisely around the corner without problems, without giving up the impact protection.
In accordance with the present invention, the method comprises, for transferring the line or marking away from the corner onto the walls, inserting the cap in the level body, and, for continuing the line or marking in the corner, removing one of the end caps from the level body so as to expose an end face thereof, and placing the end face of the level body into the corner from each side of the corner.
The basic concept of the level resides in constructing the connection between an end cap and the level body so as to be releasable, so that the end cap can be optionally removed and replaced again. On the one hand, the connection between the end cap and the level body must be capable of absorbing a sufficient force in order to prevent an unintentional separation of the end cap in the case of impacts; on the other hand, it should be possible for the user to quickly and easily remove the end cap as required and, of course, to place it back onto the level body.
In accordance with a preferred feature of the level, a locking device in the form of a resiliently mounted locking knob is provided on the shaft of the end cap with which the end cap is connected to the end face of the level body, wherein the locking knob extends into or through an indentation or opening provided at the appropriate location in the wall of the level body. Since the locking knob is resiliently fastened to the shaft, the locking knob can be resiliently inserted by applying a compressive force.
The locking knob is inserted when the end cap is mounted on the level body, however, when the indentation or opening in the wall of the level body is reached, the locking knob jumps out and ensures with its outer surface a locking action relative to the wall of the indentation or opening. By pressing in the locking knob, which advantageously is arranged on two oppositely located sides of the level body, the locking action can be released, so that the end cap can be pulled off.
While the use of the locking knob is the preferred solution, which has the advantage that no tool is required for its actuation, there are other embodiments of locking means, for example, by clamping screws or also locking means which act like bayonet closures, or also magnetic locking means.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 is a side view of a first embodiment of the level according to the present invention, shown with a portion of the wall of the level body broken away;
FIG. 2 is a side view of an end cap to be mounted on the level of FIG. 1 ;
FIG. 3 is a sectional view taken along sectional line III—III of FIG. 1 ;
FIG. 4 is a perspective view of the end cap;
FIG. 5 is a side view of a second embodiment of the level according to the present invention;
FIG. 6 is a side view of an end cap to be mounted on the level of FIG. 5 ;
FIG. 7 is a sectional view taken along sectional line VII—VII of FIG. 5 ;
FIG. 8 is a sectional view taken along sectional line VIII—VIII of FIG. 5 ;
FIG. 9 is a side view of a third embodiment of the level according to the present invention;
FIG. 10 is a side view of an end cap to be mounted on the level of FIG. 9 ; and
FIG. 11 is a sectional view taken along sectional line XI—XI of FIG. 9 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a side view of a first level 1 . The level 1 has an elongated body 2 which is constructed as a hollow profile of metal, particularly light metal, and is provided in the known manner with recesses or openings 3 and 4 for the insertion of bubbles which extend perpendicularly of each other. Of the end caps 7 arranged on the ends 5 , 6 at the end faces of the level body 1 , the end cap 7 on the left end 5 is shown inserted and partially in section, while the end cap 7 on the right end 6 is shown as FIG. 2 still outside of the body 2 shortly before being inserted.
The end cap 7 , shown in a side view in FIG. 2 and in a perspective view in FIG. 4 , is composed of an end plate 8 whose circumference corresponds approximately to the cross section of the body 2 and which with its thickness projects beyond the body 2 , and of a hollow shaft 9 connected to the end plate 8 . Together with the inner portion 10 of the end plate 8 , the hollow shaft 9 is composed of a harder plastics material of higher strength because it must ensure the connection between the end cap 7 and the body 2 , and an outer part 11 of the end plate 8 which is of a softer plastics material and serves for shock absorption. The end cap 7 can be manufactured in the known manner in a two-component injection molding process in order to ensure a permanent connection of the parts 10 , 11 .
The outer dimensions of the hollow shaft 9 are slightly smaller than the inner dimensions of the body 2 , so that the end cap 7 can be pushed in the direction of arrow 12 into the hollow space of the body 2 , as seen in FIG. 1 . In order to be able to compensate for any tolerances, ribs 13 , 14 are provided on the outer surfaces of the walls of the shaft 9 , wherein the excess dimensions of the ribs are cut off when the end cap is pushed in for the first time, so that a secure frictional engagement is ensured. Further details of the end cap 7 can be seen in FIG. 4 .
A locking knob 15 each is provided on opposite sides of the wall 23 of the shaft 9 . The locking knobs 15 each have a circular circumference and form a cylindrical portion 16 which protrudes beyond the surface of the respective shaft wall. Each locking knob 15 is located in an opening 17 of the wall 23 of the shaft 9 and is connected to the wall 23 only through two narrow webs 18 . The webs 18 are constructed so as to be resilient and twistable, so that the locking knob 15 can be pushed down by applying a pressure onto its surface, wherein the locking knob 15 returns into its original position after the pressure is no longer applied.
Corresponding to the locking knobs 15 , openings 19 are provided in the outer wall 21 of the level body 2 , wherein, in the inserted state of the end cap 7 shown in FIG. 3 , the oppositely located locking knobs 15 extend into and fill out the openings 19 . The cylindrical outer surface 16 of each locking knob 15 then is in contact with the circumference of the holes 19 , so that the end cap 7 is prevented from being separated from the connection with the body 2 of the level. By exerting a compressive force in the direction of arrows 20 , which can be easily accomplished by the thumb and index finger of a hand, the locking knobs 15 can be pushed down to such an extent that the end cap 7 can be pulled off the body 2 of the level 1 without being damaged in the direction of arrow 22 seen in FIG. 3 . The reinsertion of the end cap 7 takes place in the reverse sequence.
FIG. 5 is a side view of a second embodiment of the level 31 . The level 31 has an elongated body 32 which is constructed as an I-section of metal, particularly light metal, and which is provided in the known manner with recesses or openings 33 , 34 for inserting bubbles which extend perpendicularly of each other. Of the end caps 37 arranged at the ends 35 , 36 of the level body 32 , the end cap 37 at the end 35 is already placed on the level body, while the end cap 37 at the right end 36 is illustrated as FIG. 6 shortly before being placed on the body 32 .
The end cap 37 illustrated in FIG. 6 in a side view is composed of an end plate 38 whose circumference corresponds approximately to the cross section of the body 32 , and of a shaft 37 connected to the end plate 38 .
The shaft 39 is composed of two pairs of parallel, oppositely arranged tongues 42 , 44 . The distance between the pairs of tongues 42 , 44 is adjusted as exactly as possible to the thickness of the wall 41 of the level body 32 . Arranged between the pairs of tongues 42 , 44 is on the side of the pair of tongues 42 a resilient surface 43 which supports the resiliently lowerable projection 45 . Further details of the connections can be seen in FIGS. 7 and 8 which show sectional views along lines VII—VII and VIII—VIII in FIG. 5 .
For locking the end caps 37 to the level body 32 , the level body 32 has openings 49 into which the projections 45 engage. For releasing the end caps 37 , the artisan presses with a finger on the projection 45 and is able to pull off the end cap 37 .
FIG. 9 is a side view of a third level 51 . The level 51 has an elongated body 32 constructed as an I-section of metal, particularly light metal, and provided with recesses or openings 33 , 34 for inserting bubbles which extend perpendicularly of each other. Of the end cap 57 arranged on the ends 35 , 36 of the level body 32 , the end cap 57 on the left end 35 is placed on the level body 32 , while the end cap 57 shown in FIG. 10 on the right end 36 is still outside of the body 32 .
The end cap 57 illustrated in FIG. 10 in a side view is composed of an end plate 58 whose circumference approximately corresponds to the cross section of the body 32 and which with its thickness protrudes beyond the body 32 , and of a shaft 59 connected to the end plate 58 .
The shaft 59 is composed of two parallel, resilient surfaces 63 , wherein the distances between the surfaces 63 is adjusted to the thickness of the wall 41 of the level body 32 . A projection 65 is integrally formed on each resilient surface 63 . Both projections 65 engage in the openings 49 in the wall 41 of the level body 32 , as can be seen in FIG. 11 .
To be able to separate the end cap 57 from the level body 32 , the ends 64 of the resilient surfaces 63 are constructed as actuating surfaces, as illustrated in FIG. 11 .
While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles. | A water or spirit level is composed of an elongated body, preferably of metal, at least one bubble mounted in the elongated body, and end caps, preferably of plastics material, at the end faces of the elongated body, wherein at least one outer surface of the elongated body constitutes a preferred measuring surface. At least one of the end caps is releasably connected to the level body such that the end cap can optionally be removed and once again replaced. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The invention relates to graphical user interfaces. More particularly, the invention relates to displaying forms and content in a browser.
[0003] 2. Related Art
[0004] The Internet has radically changed both the content and speed at which companies disseminate information. The Internet has also provided a means by which companies can assist their clients through the use of posting relevant information on the companies' web sites. The clients later visit the web sites and retrieve and or submit information from to the companies.
[0005] The Internet has seen processing to specify and sometimes manipulate this information shift in location from being handled on the server providing a web site to the actual client computer (referred to herein as the client). One way of accomplishing scripting content for use on a client is through the use of Java.
[0006] Java applets are small programs that run in the memory of a client. Despite developers striving to provide highly integrated content between the standard HTML and Java, conventional implementations of Java and HTML force a user to use various windows and different graphical user interfaces (GUIs) as HTML and Java are not tightly integrated. For example, FIG. 1 shows how a browser (for example, Netscape from Netscape, Inc. or Internet Explorer 5.5 from the Microsoft Corporation) handles HTML and Java. As is known in the art, the browser executes on a computer system comprising a processor and a display. FIG. 1A shows incoming HTML 101 being displayed in a browser 102 . FIG. 1B shows a Java applet 103 being received and run in browser 102 . While Java applets contain text, they do not normally contain HTML content. Any text in an applet is generally displayed as in a window 104 separate from that of the display of the running Java applet 105 . While most experienced users would not mind the opening and closing of various windows, novice users may become flustered.
[0007] Further, Java applets are dynamically run on a user's machine. Because of the failure to store persistence information relating to previous interactions with the Java applet, navigation away from then back to the Java applet will re-execute the applet thereby replacing any previously entered information.
[0008] A further problem that needs to be overcome when forms are displayed as a result of activating an HTML hyperlink is that navigating away from the form then back to the form can be difficult. If the Java form was treated as HTML content is conventionally treated, then the form may be lost in a long history of visited pages. Further, with Java applets, only one form is generally opened at a time as only one applet is normally active. Navigating to a new page or new form shuts down the previously running applet and fails to save previously entered information. FIG. 2 shows a user initiating an applet 202 from browser 201 . Prior to completing the interaction with applet 202 , a user may choose to navigate to new page 203 or back to page 201 . Attempting to re-navigate to applet 202 may completely refresh the running of the applet and destroy all previously entered information. For long forms, a user will quickly tire of needing to reenter previously entered information
[0009] Accordingly, tighter integration between forms and content is needed.
SUMMARY
[0010] A system and method for integrating forms and content is disclosed. By integrating both forms and content, the drawbacks of the prior art are reduced. The present invention includes a container that houses an applet that displays both forms and HTML content. In other words, the present invention displays static HTML data and dynamic Java form data in a single window. The invention permits a user to interact with a form created by a Java applet, navigate away, and have the form content maintained in the applet as the applet is not shut down. Also, as the invention maintains the content of the form with its incorporated HTML content, a user may open a new form without concern that the previous form and content will be deleted.
[0011] In one embodiment, the user may navigate static HTML hyperlinks to open new Java forms. The new form may be added to the running applet with a tab or other easy way of accessing the new form added to the graphical user interface displaying the forms. The user may navigate to HTML content from inside the running Java applet. Multiple forms may be opened simultaneously and may be accessed by tabs. In a further embodiment, an icon is displayed that, when activated, retrieves all forms and entered data. Activating the icon displays a graphical user interface that shows all open forms. The presence of this icon and its functionality assures a user that open forms and entered data may always be retrieved. By providing a way to access all open forms, the forms are not lost through a string of HTML navigations.
[0012] The invention also allows integration of HTML content and Java forms by enabling the user to open a new form by clicking an HTML hyperlink. New HTML content may also be displayed by navigating links in the displayed forms. These links or buttons may include Help buttons and the like. Activating these links or buttons redirects the applet to display the content of the HTML page associated with the button or link. In this regard, the applet is not shut down but rather the content of the new page is displayed in the applet housed by the container.
[0013] These and other aspects of the invention will be apparent from the following drawings and description.
BRIEF DESCRIPTION OF DRAWINGS
[0014] [0014]FIGS. 1A and 1B show conventional methods of displaying content and forms in browsers.
[0015] [0015]FIG. 2 shows conventional navigation between forms and HTML pages.
[0016] [0016]FIG. 3 shows the combination of forms and content in accordance with embodiments of the present invention.
[0017] [0017]FIG. 4 shows the display of form content in response to user input in accordance with embodiments of the present invention.
[0018] [0018]FIG. 5 shows an architecture for supporting the present invention.
[0019] [0019]FIG. 6 shows a method for performing the present invention.
DETAILED DESCRIPTION
[0020] The present invention relates to displaying both forms and content in a common graphical user interface. The present invention may be embodied as a Java applet that, when retrieved and run in a browser, the invention displays a form or forms to a user. The Java applet is housed in a container. A container is an application program or subsystem in which the program building block known as a component is run. For example, a component—such as a button or other graphical user interface or a small calculator or database requester—may be developed using JavaBeans that can run in Netscape containers such as browsers and in Microsoft containers such as Internet Explorer, Visual Basic®, and Word.
[0021] [0021]FIG. 3 shows a form displayed in accordance with embodiments of the present invention. Form 302 is a form displayed in display 301 . The contents of the form 302 are generated by a Java applet 304 . The applet also contains HTML information 303 . This information is also displayed in form 302 . The Java applet may be downloaded from the Internet, retrieved locally, or obtained by any other means of retrieving information known in the art. While FIG. 1 displays the content of a Java applet apart from the content of browser 102 as window 104 , the present invention combines both the HTML content and forms content together in a display of the form.
[0022] The browser display 301 includes back button 305 and icon (or button) 306 . Activation of back button 305 directs the browser to display previously displayed content. As is known in the art, as one navigates HTML pages, links to the pages are stored in a history stack (not shown for simplicity). By activating the back button 305 , the browser is redirected to the top link in the history stack. The present invention includes the ability to add links to forms in the history stack.
[0023] As an example, the browser 301 displays pane 302 comprising a form. The form includes HTML text 307 and buttons 311 and 312 . The form also includes form fields 308 and 310 . As shown in FIG. 3, the form may be used as forms are normally used including in ordering books on-line, in e-commence in general, in configuring systems (like a system gateway for a computer system), and other form related applications as are known in the art.
[0024] The system uses Java-based classes including JEditorPane to control when a form is displayed. The form may include a variety of information as is known in the art. The system also instantiates objects from HTMLEditorKit classes to control the display of the HTML content 303 received from applet 304 . Finally, the system uses HyperLinkListener to monitor for operation of hyperlinks in pane 302 . While browser 301 may navigate to new content based on the activation of hyperlinks in it, operation of hyperlinks in pane 302 need to be controlled so as to not refresh the content of any dynamic forms in pane 302 . This is performed by having new forms or pages displayed in the running Java applet, rather than permitting the applet to be completely replaced by the browser's redirection to new content. With the use of the applets described here, one may use conventional browsers to realize the present invention.
[0025] In one embodiment, the present invention displays HTML content by instantiating javax.swing.text.html.HTMLEditorKit and javax.swing.JeditorPane. The javax.swing.event.HyperlinkListener interface is implemented by the classes in the invention. The various classes are described in additional detail in respect to FIG. 5.
[0026] HyperEvents with the description field starting with “http:// “ cause the corresponding HTML page to be displayed in area 302 . HyperlinkEvents with the description field starting with “form://” cause the container (specifically the workbench container 302 of FIG. 4) to be displayed in the browser and the corresponding form to be added as a new tab in the container 302 .
[0027] The invention may be practiced using Java Developer Kit 1.2.2-001 available from Sun Microsystems, Inc. This developer kit contains the Java Runtime Environment 1.2.2-001.
[0028] [0028]FIG. 4 shows browser 301 having multiple active forms in pane 302 . The forms are represented by tabs 401 , 402 , and 403 . A new tab 405 is shown in broken lines. The contents of each tab are shown in display region 404 once the tab is selected. The content of each form, represented by tabs 401 , 402 , and 403 , is separately maintained. Accordingly, navigation in window 404 does not refresh the currently displayed form or other forms (unless specified by, for example, navigation of a “reset” or “close” button as is known in the art). The Java forms get and set persistence information by communicating with a server process using one of the known communication protocols (for example, CORBA, RMI, or JDBC).
[0029] [0029]FIG. 5 shows an architecture for supporting the invention. Applet 501 is from a class extending javax.swing.Japplet. Event manager 502 is a class implementing java.awt.event.ActionListener. History stack 503 is a stack class extending java.util.Stack. Workbench button 504 is a short cut button that, when activated, extends javax.swing.Jbutton. The action command field of this button is set to “wb://wb”. Workbench 505 is a class extending javax.swing.JtabbedPane (resulting in the tabbed panes of FIG. 4). Form factory 506 is a factory class as is known in the art that creates forms based on a string reference in the applet. Forms 507 and 508 are form classes extending javax.swing.JPanel.
[0030] HTML Panel 509 is a class for displaying HTML content extending javax.swing.JEditoryPane with a javax.swing.text.html.HTMLEditorKit object set as the current editor kit. This class also implements javax.swing.event.HyperlinkListener.
[0031] Back Button 510 is a navigation button extending javax.swing.JButton. The action or command field of this button is set to “back://back”.
[0032] The flow of events are described as follows. All hyperlinks in the HTML content displayed in HTML Panel 509 are handled by the Panel 509 . When the Panel 509 receives a javax.swing.event.HyperlinkEvent, Panel 509 creates a java.awt.event.ActionEvent with the command field of the ActionEvent set to the description of the HyperlinkEvent. Panel 509 next forwards the ActionEvent to event manager 502 . Workbench 505 listens to events from controls (or buttons operable by the user) on open form objects ( 507 and 508 ). The workbench 505 may also perform some filtering by eliminating events that do not need additional action. All events that cause a new form or HTML page to become visible are forwarded to event manager 502 . All other events are ignored. Finally, event manager 502 listens to events from buttons 504 and 510 .
[0033] When a relevant event occurs, event manager 502 determines what action to take in response to a java.awt.event.ActionEvent by examining the command field associated with the event. If the command field starts with “wb://”, then the follow steps occur:
[0034] 1) If the HTML panel 509 is visible, then it is hidden; and,
[0035] 2) If the Workbench 505 is hidden, it is made visible.
[0036] If the command field starts with http://, then the following steps are taken:
[0037] 1) If the HTML panel 509 is hidden, then it is made visible;
[0038] 2) If the Workbench 505 is visible, it is hidden;
[0039] 3) The current page of the HTML Panel is set to the command field; and,
[0040] 4) A new entry is placed in stack 503 with the contents of the command field.
[0041] If the command field starts with “form://” then the following steps are taken:
[0042] 1) If the HTML panel 509 is visible, then it is hidden;
[0043] 2) If the Workbench 505 is hidden, it is made visible;
[0044] 3) The contents of the command field are passed to form factory 506 to create a new form object (for example, 507 and 508 );
[0045] 4) The newly created form object is added to the workbench 505 ; and
[0046] 5) A new entry is placed in stack 503 with the contents set to “wb://wb”.
[0047] If the command field starts with “back://”, then the following steps are taken:
[0048] 1) The top entry (or other entry) of stack 503 is removed (or popped as is known in the art); and,
[0049] 2) The contents of the newly removed stack entry are used to set the command field of the current ActionCommand and the ActionCommand is reprocessed.
[0050] [0050]FIG. 6 shows a method of creating and navigating form content in accordance with the present invention and graphically shows the addition of a new form and HTML. In step 601 , a Java applet is run. In step 602 , the applet instructs a browser to open a display window and populates the window with form information, in step 603 . In step 604 , the Java applet retrieves HTML content and forwards the content to the browser for display in the window. In step 605 , the Java applet running in the browser monitors navigation commands. These commands may take the form of events generated through selection of hyperlinks or other actions as are known in the art (including activation of buttons, icons, and the like). In step 606 , the system determines if a new form is to be created. If so, the system adds a link to the currently displayed form or HTML page to the history stack (in step 607 ), displays the workbench container (in step 608 ) and adds a new tab ( 405 ) in the workbench container for accessing the new form (in step 609 ).
[0051] In step 610 , the system determines if new HTML content is to be displayed. If so, the system adds a link to the current form or HTML page to the history stack (in step 611 ), hides the workbench container if visible (in step 612 ), and shows the new HTML page (in step 613 ).
[0052] Otherwise, the system continues to monitor for new actions or commands.
[0053] Various embodiments have been described. It is appreciated that various modifications of the embodiments are known to those of skill in the art and are considered within the scope of the present invention. For example, instead of using Java, one may use ActiveX controls to implement the current invention. Also, instead of using horizontally arranged tabs, one may use vertically arranged tabs. Further, one may substitute frames or a combination of frames and tabs to display forms.
[0054] The scope of the invention is intended to be limited only by the following claims. | The present invention relates to a system and method for presenting both forms and content in a browser. The invention includes a Java applet having a graphical user interface that receives and projects HTML content to the user. By being able to combine both forms and non-forms content in a single interface, a tighter integration of information is achieved. Further, form content is maintained during navigation though storing active forms in a workbench. | 6 |
FIELD OF THE INVENTION
The invention relates to a trim press for automatically trimming or deburring die castings or castings.
THE PRIOR ART
DE-PS 30 36 333 No. discloses an apparatus for removing workpieces on a pressure pouring or die casting machine in which a trimming tool consisting of a trimming die and a countermold is disposed on a machine frame for deburring or trimming the workpiece provided with casting or die casting burrs. For this purpose, one of the two halves of the cutting tool is slidably mounted on the machine frame to open the trimming tool. To introduce the workpiece into the opened trimming tool, a workpiece transfer means is provided which has a pivot arm timed to pivot about a pivot axis fixed to the frame. A workpiece holder to receive the casting to be trimmed or deburred is provided at one end of the pivot arm.
With the apparatus previously known, the direction of the trim stroke is horizontal, the transfer means consists of a carrier supported by a horizontal driving shaft, on which there are arranged, offset by 90° each, four cylinder piston units, including piston rods on which there is disposed one transfer arm each for receiving a workpiece. The transfer motion thus takes place on a vertical plane, a pure circular motion, however, being insufficient for receiving and transferring the workpieces into the trim form. Thus, a relatively complex course of motion is employed which, on the one hand, is constituted by a multiple linear movement of the cylinder piston units and, on the other hand, by a sliding movement of the carrier, coordinated to the rotary movement, on the driving shaft. The known apparatus is not only structurally complex but the arrangement of the workpieces on relatively thin, long piston rods renders a transfer of heavy castings by the transfer means almost impossible. This is further complicated since the prior art castings are fixed by bridges joined by the piston rods of the transfer means whose inherent rigidity, particularly in the hot state, does not sustain high bending moments, thus, the need for much heavier molds. Finally, in accordance with the prior art, it is necessary to position the deburring machine directly adjacent the mold and this is not always necessarily desirable for intraplant reasons or space allocation.
BRIEF SUMMARY OF THE INVENTION
The object underlying the present invention is to create a trim press suited to treat castings of both a simple and robust construction and wherein the workpiece transfer means provides an exact feed of the workpiece to the press as well as a separation of the deburred castings from the trimmed waste parts in a relatively simple mode by relatively simply courses of motion.
DETAILED DESCRIPTION OF THE INVENTION
The present invention makes advantageous use of the feature that the workpiece holder for transferring the casting into the trim position is formed by the portion of the trimming die which is rigidly fixed at a constant distance from the pivot axis on the end of the pivot arm, thus following a generally circular path. Thus, the entire pivot means can be rigidly formed such that even very heavy castings, for example, engine motor blocks and the like, may be transferred from one position into the other without difficulty. By the provision of the pivot motion, it is possible to perform the necessary operations at sequential positions. For example, in a first pivot position, the introduction of the workpiece onto the trimming die is accomplished while in a second pivot position, the actual trimming procedure is performed. In a third pivot position, the trimmed burrs are discharged into a waste collector. The main plane of the workpiece holder most advantageously slopes upwardly in the first position in which the workpiece is being fed. Thus, lateral feeding of the workpiece is possible by the workpiece's own weight and positioning in the trimming die secured without additional holding means. The trimming procedure is carried out by a trimming movement directed vertically from above and relatively high acceleration peaks may be employed within the supporting structure of the machine frame without difficulty. In the third position (discharge position), it is advantageous to pivot the trimming die into a position such that its surface slopes downwardly with the waste falling more or less on its own into the waste collector.
A collecting means is attached to the workpiece holder and projects laterally therefrom. The workpiece holder faces the countermold constituting the tool half containing the deburred workpiece in the first position. The trimming die may then be reloaded and, at the same time, a discharge means disposed in the countermold, separates the trimmed workpiece from the mold and when the workpiece holder pivots into the second position, the trimmed product may be passed on automatically into a product receptacle. For this purpose, the collecting means advantageously is formed as a slide extending approximately horizontally under the countermold in the first position and moves with the workholder to slope downwardly toward the workpiece receptacle in the second position. Thus, the workpiece released from the countermold falls into the collector and slides virtually synchronously with the pivot movement, slightly accelerated by the increasing slope of the collector surface and discharges into the workpiece receptacle.
After the trimming procedure, the blank remains temporarily in the countermold which lifts upwardly from the trimming die and remains there until the trimming die has returned from the third position to the first position. Thereafter, workpiece discharge means in the countermold presses the blank out of the countermold onto the collector lying thereunder for subsequent delivery to the workpiece receptacle.
If the vertical axis of the trimming die aligns with the center of the pivotal axis for the pivot arm, it is insured that during the trimming procedure and the application of the trimming forces, no tilting moments are exerted on the trimmng die and thus on the pivot arm and its driving elements. On the contrary, the trimming forces are directly transferred to the machine frame through the bearings of the pivot axis. This provides not only a load-cushioning function for the machine parts but also achieves accurate trimming results. Due to the arrangement of the countermold, the trim die and the pivot axis, when the pivot arm is in the second position (working position), each is in an aligned superposed vertical orientation.
Between the pivot axis and the trim die, the pivot arm defines a laterally U-shaped or sickle-shaped configuration with the bight of the U extending in the pivot plane. The advantage of this shape is that the pivot arm and the members attached thereto, namely the workpiece holder trim die and the collector, laterally aligns with the frame guide columns, when pivoting into the second position, much like a hook, on which columns the countermold is supported for its vertical trim movement.
To support the pivot arm and its components connected with the workpiece holder and trim die, particularly during the trimming step, a support block engages the underside of the pivot arm in the second pivot position (working position) and provides a direct force transmitting path to the machine frame. The pivot arm thus directly overlies the support block and to insure the most effective transfer of forces through the pivot arm components and onto the support block, the surface of the support block includes an inclined ramp portion.
To move the pivot arm between the first and second positions, a driving cylinder is provided. The piston rod is connected to an extension of the pivot arm projecting beyond the pivot axis. The connection defines a knee action in the first position when the piston rod is extended and the pivot arm is in the first or third position and vertically aligned with the pivot axis in the second position.
To move the pivot arm out of the aligned or "dead center position" on the pivot axis, a gear wheel is fixed to the pivot arm and a rack driven by a secondary driving cylinder meshes peripheraly with the gear wheel. Thus, after the trimming step is completed, transfer of the pivot arm from the second to the third position is initiated.
The members coacting with the trimming die including the countermold, feeding means and product collector, etc. must necessarily be arranged on a generally circular path within the arc of movement of the pivot arm. It is desirable to provide between the first and the second positions a pivot angle of about 50° and between the first and the third positions a pivot angle of about 75°. Such relationships limit the space requirements to accommodate the swinging movement of the pivot arm to one side of the frame. Due to the relatively large pivot angle between the first and the third positions, the workholding surface of the trimming die is directed generally downwardly in the third position and thus the trimmed waste parts collected thereon tend to fall free of the die without difficulty.
Preferably, the workpiece feeding device is formed as a conveying stemple linearly directed toward the pivot axis and its front face carries the workpiece to be fed to the workholder. The sliding movement of the stemple describes an angle of about 50° with the direction of the trim stroke such that the workpiece is properly placed in the trim die when the pivot arm and die are in the first position.
To clean the surface of the trim die in the third position for the removal of residual trim cuttings and the like, one may provide spraying means for cleaner and or lubricant under pressure onto the surface, simultaneously cleaning and pre-lubricating the die preparatory for the next trimming procedure.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in detail by the aid of an example of embodiment in the figures of the drawings.
FIG. 1 shows a schematic elevational view of the trim press in the first position (receiving position);
FIG. 2 is a schematic elevational view of the trim press in the second position (trimming position); and
FIG. 3 is a schematic elevational view of the trim press in the third position (ejecting position).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A trim press 10 for the automatic deburring of die castings or castings 12, 12' consists of a machine frame 14 on which there are disposed two selectively coacting cutting tool halves including a trimming die 16 and countermold 18. The countermold 18 is slidable along vertically positioned guide struts 20 between open and closed positions. The machine frame 14 includes a pivotally mounted arm acting as a transfer device designated generally at 24, turning about a fixed pivot axis 22. A workpiece holder 28 is carried by one end of the pivot arm 26 to receive and support a casting 12 to be deburred. The workpiece holder includes a trim die 16 and is movable with pivot arm 26 between three positions. The trim die 16 is fixedly spaced from pivot axis 22 and the die main plane lying always is paralel to pivot axis 22.
In the first position shown in FIG. 1 (receiving position), workpiece holder 28 of the trim die 16 is directed toward a workpiece feeding means 30 formed as a conveying stemple 32 directed toward pivot axis 22. Said stemple carries the casting 12 on its front face 34 for delivey to the workpiece holder 28.
In the second position shown in FIG. 2 (trim position), the pivot arm and the workpiece holder 28 of trim die 16 carried thereon together with the casting to be trimmed are rotated about the pivot 22 to a position parallel to the bottom side 36 of countermold 18. In the third position (ejecting position of FIG. 3), pivot arm 24 and workpiece holder 28 are rotatably directed toward a waste collector 38 including conveyor belt 40 as well as a waste basket 42. Thus, as seen in FIGS. 1, 2 and 3 of the drawings, workpiece holder 28 of the trim die 16 is inclined upwardly in the first position extends horizontally in the second position and is angularly downwardly directed in the third position. The entire arc of movement of pivot arm 26 and of trim die 16 affixed thereto takes place essentially in the space on the left side of pivot axis 22 in the sample of the illustrated embodiment. The feeding means 30 and the waste collector 38 are both disposed on the same side of or on machine frame 14.
On one edge 44 of workpiece holder 28, product collecting means 46 is positioned and is formed essentially as a slide extending approximately horizontally in the first position and is sloping downwardly in the second position. The lower end 48 of the collecting means in the second position of FIG. 2 is adjacent a product collector 50 formed as a basket to receive the trimmed castings 12' deposited on collector 46 in the first position, which slide after deposit in workpiece collector 50 in the direction of arrow 52 in the second position
As evident from FIG. 1, the trim mold 18 moves vertically between closed trimming and open non-trimming positions along the guide struts 20. When moved to the open position, the countermold 18 lifts from the trim die 16. The casting 12' is initially retained by friction fit in a die recess 54. To release the casting from said die and to eject it onto the receiving means 46, an ejector in the form of punch 58 is slidably provided in countermold 18. The punch includes a lower front surface 60 which engages the workpiece 12' and presses it out of the countermold.
The vertical centerline 62 of trim die 16 is perpendicular to the center of pivot axis 22 and coaxial with the trimming direction 56 in the second position.
Between pivot axis 22 and trim die 16, the pivot arm 26 is generally U-shaped in the pivot plane (paper plane of the drawing figures) and thus, the upper part of pivot arm 26 carrying the trim die 16 and the collecting means 46 can enter between the guide struts 20 when pivoting into the second position. The underside of the pivot arm underlying the workpiece holder is contoured as at 64. A correspondingly contoured surface 66 of a support block 68 engages the underside 64 of the pivot arm and provides a rigid support for the trimming operation when trimming pressures are applied. The cooperating contoured surfaces may include a planar portion between inner contour 64 and surface 66.
Pivot arm 26 is provided with an extension 70 which at its extremity 72 is pivotally connected by a joint with the driving end 74 of piston rod 76 of a first driving cylinder 78, the piston rod 76 and extension 70 forming the legs of a knee joint 80. In the second position, knee joint 80 is aligned with the longitudinal axes of extension 70 and of driving cylinder 78 in alignment with trim direction 56 and the vertical centerline 62.
To move pivot arm 26 along with the members arranged thereupon from the second position into the first or third position, a pinion gear wheel 82 is arranged on pivot axis 22 and coupled to pivot arm 26. A rack 86 driven by a second driving cylinder 88 engages the pinion 82. Shifting movement of rack 86 is controlled by an incrementally operating linear transmitter (not shown) to control the exact position of the pivot arm in the three positions and may be controlled by a stored-program control and computer, if desired.
A sprayer 90 may be used to spray a combination cleaning, cooling and lubricating agent under pressure onto the surface 28 of trim die 16 when it is pointing downwardly in the third position as best seen in FIG. 3 of the drawings and thus insures that waste chips are removed thoroughly from the trim die between each operational sequence.
OPERATIONAL SEQUENCE
Considering now the operational sequence of the device, it will be recognized that there are generally three primary positions. These are referred to as first, second and third positions. The first position is illustrated in FIG. 1. In this position, the trim die 16 and workpiece holder 28 are directed against feeding means 30 whose conveying stemple 32 introduces workpiece casting 12 to the holder 28. Simultaneously, punch 58 in countermold 18 presses casting 12' deburred during the preceding trimming procedure out of countermold 18 and it is deposited on receiving means 46. Pivot arm 26 along with the members mounted thereupon now pivots into the second position.
The second position is illustrated in FIG. 2. In this position, countermold 28 is moved downwardly against the work holder 28 and trim die 16, deburring casting 12 by this action while simultaneously, the collecting means 46 slopes downwardly and casting 12' previously deposited therein moves by gravity into product collector 50. Casting 12 is now deburred by the action of the die 16 and countermold 18. Die 54 lifts upwardly in the direction of the arrow and carries the trimmed casting therewith. Trim die 16 is thus free for being pivoted into the third position.
The third position is illustrated in FIG. 3. In this position, the chips, burrs, lugs and the like left in the cavities and recesses of the trim die 16 fall onto the conveying belt 40 and are transferred into waste receptacle 42. Spraying means 90 is activated and washes out any remaining chips from trim die 16. The press is then returned to the first position of FIG. 1 where it is supplied with a new casting, as been described above, and the casting already deburred is deposited in the receiving means and the sequence is repeated. | A multiple station sequentially operating trim press is arranged to receive workpieces for subsequent transfer from a loading station to a treatment station by means of a pivotally mounted workpiece support. After trimming and deburring, the workpiece is transferred to a collection station and the workpiece support is moved to a cleaning station where its surface is washed free of residual trimmings. The workpiece support is then returned to its loading station and the sequence repeated. | 8 |
CROSS-REFERENCE(S)
This application is a divisional application of application Ser. No. 11/493,859 filed on Jul. 26, 2006, now U.S. Pat. No. 7,935,334 the entire disclosure of which is incorporated into this application by reference and to which the instant application claims priority. Co-pending application Ser. No. 11/493,859 further claims priority from provisional Application No. 60/705,730 filed Aug. 5, 2005, and is a continuation-in-part of application Ser. No. 11/177,264, filed Jul. 7, 2005, which further claims priority from provisional Application No. 60/585,941, filed Jul. 8, 2004.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
REFERENCE TO A “MICROFICHE APPENDIX”
Not Applicable.
BACKGROUND
Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Probiotics are described as “live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host” (reports of the United Nations Food and Agricultural Organization and the World Health Organization, Alternative Medicine 2001). Probiotics are widely applied as nutritional supplements in animals and humans. For example, yeast is used as a nutrient supplement for livestock, and yogurt with lactic acid bacteria-Lactobacillus and/or Bifidobacterium is commonly used to prevent and cure diarrhea-related gastrointestinal (GI) infectious diseases (Alvaez, et al, 2001; Fuller 1989; Majamaa, et al 1995). Multiple unique properties of probiotics such as anti-infectious properties, immune modulatory effects, enhanced barrier functions, metabolic effects and alternations of intestinal mobility or function make probiotics an effective type alternative medicine for animals and humans (Walker and Buckley, 2006).
Although probiotic products like short chain fatty acids (SCFA), cell wall peptidoglycan and short chain DNA fragments containing CpG sequences can have beneficial probiotics effects, the administration of live microorganisms to animals and humans remain to be the core application and research studies of probiotics (Walker and Buckley, 2006). In order to have the maximum effects of probiotics on animals and humans, one has to administrate live bacteria to reach gastrointestinal tracts for multiplication (Kailasapatha and Chin 2000). Lactobacillus spp and Bifidobacterium spp are two most commonly probiotics described in scientific literature and in commercial products. Both Lactobacillus spp and Bifidobacterium spp are facultative anaerobic bacteria. Most species (or strains) of Lactobacillus and Bifidobacterium are sensitive to the exposure of oxygen (Gomes et al, 1995; Talwalkar and Kailasapathy, 2004) and high temperature. It is difficult to maintain the viability of Lactobacillus and Bifidobacterium at room temperature under consistent open and closure operations. Therefore, variable results are often described, especially for commercially available products that are required to have long term storage and shipping in various temperature (Tuomola et al., 2001).
U.S. Pat. No. 5,968,569 discloses a pet food product of a gelatinized starch matrix including a probiotic micro-organism. Specifically disclosed are Saccharomyces and Pediococcus acidilactici.
U.S. Pat. No. 6,551,633 discloses a milk based powder for pets which includes lactase and lactose. Also disclosed are the probiotic organisms of U.S. Pat. No. 5,968,569.
U.S. Pat. No. 6,780,447 discloses animal foods comprising sorbic acid and live or dead microorganisms. A very large number of species is disclosed including P. acidilactici.
U.S. Pat. No. 6,827,957 discloses animal foods of specific formulation having a soft inner component and a hard shell along with probiotics. Specifically, Saccharomyces is disclosed.
U.S. Pat. No. 6,835,397 discloses an encapsulated yeast including a variety of probiotics including Saccharomyces. boulardii and Pediococcus. acidilactic (sic).
US Pub. Pat. Applic. 2003/0049240 discloses a method for treating helicobacter infections including the use of Lactobacillus and Bifidobacterium.
US Pub. Pat. Applic. 2003/0109025 discloses methods for treating helicobacter infections including the use of Lactobacillus and Bifidobacterium.
US Pub. Pat. Applic. 2004/0197352 discloses a prebiotic composition which reduces creatine and BUN and includes a variety of microbial species.
US Pub. Pat. Applic. 2003/0165472 discloses a method for the storage and delivery of microorganisms.
US Pub. Pat. Applic. 2006/0008511, incorporated herein by reference, discloses probiotic microbes encapsulated in a mixture of xanthan gum and chitosan, or in gelatin.
REFERENCES
Alvaez, S., Herrero, C., Bru, E., Perdigon, G. 2001. Effect of Lactobacillus casei and yogurt administration on prevention of Pseudomonas aeruginosa infection in young mice. J. food Prot. 64: 1768-1774.
Dalloul, R. A., H. S. Lillehoj, J.-S. Lee, S.-H. Lee, and K.-S. Chung. 2006. Immunopotentiating effect of a Fomitella fraxinea -derived lectin on chicken immunity and resistance to coccidiosis. Poult. Sci. 85: 466-451.
Fuller, R. 1989. Probiotics in man and animals. A review. J. Appl. Bacteriol 66: 365-78.
Gomes A. M. P., Malcata F. X., Klayer F. A. M., Grande H. J. 1995 Incorporation and survival of Bifidobacterium sp. strain Bo and Lactobacillus acidophilus strain Ki in a cheese product. Netherlands milk and dairy journal vol. 49: 71-95.
Isolauri, E. 2003. Probiotics for infectious diarrhea. Gut 52: 436-437.
Kailasapatha K, Chin J. 2000. Survival and therapeutic potential of probiotic organisms with reference to Lactobacillus acidophilus and Bifidobacterium spp. Immunol Cell Biol. 78: 80-88.
Lillehoj, H. S., W. Min, and R. A. Dalloul. 2004. Recent progress on the cytokine regulation of intestinal immune responses to Eimeria . Poult. Sci. 83: 611-623.
Majamaa, H., Isolauri, E., Saxelin, M., Vesikari, T. 1995. Lactic acid bacteria in the treatment of acute rotavirus gastroenteritis. J. Pediatric Gastroenterol Nutr 20: 333-339.
Perdigon, G., Fuller, R., Raya, R. 2001. Lactic acid bacteria and their effect on the immune system. Curr Issues Intest Microbiol. 2(1): 27-42.
Talwalkar A, Kailasapathy K. 2004 The role of oxygen in the viability of probiotic bacteria with reference to L. acidophilus and Bifidobacterium spp. Curr Issues Intest Microbiol. 5(1): 1-8.
Tuomola, E., Crittenden, R., Playne, M., Isolauri, E., and Salminen, S. 2001 Quality assurance criteria for probiotic bacteria. Am J Clin Nutr 73(suppl): 393S-398S.
Walker, R. and Buckley, M., 2006 “Probiotic Microbes: The Scientific Basis” 2006
A report from the American Academy Microbiology, page 1-28. by Pensare Design Group.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.
BRIEF SUMMARY
The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tool and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.
Embodiments disclosed include a preparation for pets comprising probiotic microbes encapsulated in a mixture of xanthan and chitosan gums. Embodiments disclosed include a preparation for pets comprising probiotic microbes encapsulated in a gelatin capsule. In embodiments the probiotic microbes comprise Saccharomyces yeast and lactic acid bacteria. In embodiments the probiotic microbes comprise yeast. In embodiments the probiotic microbes comprise lactic acid bacteria. In embodiments the yeast is Saccharomyces . In embodiments the lactic acid bacteria is Pediococcus . In embodiments the Saccharomyces yeast is Saccharomyces cereviase boulardii also termed Saccharomyces boulardii . In embodiments the lactic acid bacteria is Pediococcus acidilactici . In embodiments the xanthan gum concentration is from about 0.2 percent weight by volume to about 2 percent weight by volume and the concentration of chitosan gum is about 0.1 percent weight by volume to 1.0 percent weight by volume and the pH is from about 2 to about 7. In embodiments the xanthan gum concentration is from about 01.25 percent weight by volume and the concentration of chitosan gum is about 0.4 percent weight by volume and the pH is about 4.15. Embodiments include the process of treating infectious gastrointestinal disease in birds and mammals in need of such treatment which comprise the step of feeding the bird or mammal in need of treatment encapsulated probiotic microbes or include the probiotics in animal food or animal treats. Embodiments include the process of enhancing immune responses against antigens in birds and mammals which comprise the step of feeding the bird or mammal in need of treatment encapsulated probiotic microbes or include the probiotics in animal food or in animal treats.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the relationship between pH and capsule hardness.
FIG. 2 shows the relationship between viability of encapsulated and unencapsulated probiotic microbes and reduced temperature.
FIG. 3 shows the relationship between viability of encapsulated and unencapsulated probiotic microbes and elevated temperature.
FIG. 4 shows the relationship between viability of encapsulated and unencapsulated probiotic microbes and time of exposure to pH 2.
FIG. 5 is a graph showing the effect of probiotics on antibody response.
FIG. 6 is a graph showing the effect of probiotics on cellular immune response.
FIG. 7 is a graph of fecal oocytes shed by birds infected by E. acervulina.
FIG. 8 is a graph of fecal oocytes shed by birds infected by E. acervulina or E. tenella.
DETAILED DESCRIPTION
Probiotics are the beneficial living bacteria that naturally exist in the gastrointestinal (GI) tracts of humans and animals. Probiotics are well accepted as the food supplements for human consumption. When patients have discomforts of digestive systems because of treatment with antibiotics or suffering form travel, doctors often recommend the patient to take probiotics to restore the microflora in patient digestive systems. Recently, the medical community increasingly recognizes probiotics as the agents that are able to enhance human immune responses for improving the efficacy of vaccine and for disease prevention. Probiotics are quickly regarded as one of the primary categories by the functional food industry. In farm animals such as pigs, cattle, dairy cows and poultry, probiotics are widely used as the substitutes for antibiotics as the growth promoters. Producers have recognized the beneficial effects of probiotics that not only improve the animal growth but also reduce the infection of enteric pathogens significantly. The beneficial effects of probiotics on pets (dogs, cats, and other small animals like guinea pigs) have attracted many researchers to investigate the mechanisms, and the research results were published in many journals. Today, pet food manufactures include probiotics as one of the important ingredients in many premium pet foods. Probiotics in capsules or chewable tablets for pet application are also commercially available. However, pet owners either are not familiar with probiotics or have experiences with the variable Probiotics effects on pets, and have doubts about the real functions of probiotics. Although the trends for human and farm animals have accepted probiotics as the nutrient supplements or as powerful neutraceutical products, pet owners are not fully aware that probiotics can contribute significant effects on pets in good health to expand their life span.
How do probiotics function as the beneficial effects on pets? Probiotics have to be able to travel along pet's GI tracts. When they have the opportunity to attach to GI tract surfaces, probiotic microorganisms can start to replicate. When probiotic microorganisms replicate and grow, they will decompose the food token by pets to produce acid compounds, which will create unfavorable acidic environments for most of GI tract pathogens to survive. Some of the probiotics also secrete the toxic compounds that are harmful to the pathogens. Moreover, as the probiotics attached to pet's GI tracts, they become generic immunogens, raise the antibody production and enhance the pet immune response for pathogen infections. As probiotic microorganisms multiply, they occupy the surfaces of GI tracts and prevent the possibility for the pathogens to attach to pet's GI tracts for infection. During the process of multiplications, Probiotics degrade the complex food compounds into the simple nutrition for pets to absorb and to utilize. This will not only help the pets to strengthen their bodies but also reduce the bad odors typically generated by pets caused either by the incomplete food digestions or by excess gas production through different digestion pathways. Therefore, in order to have the effects of probiotics on pets, the pet owners have to make sure to deliver the live probiotics into pet's GI tracts for microorganisms to multiply and to grow. It is critical to have the sources of viable probiotics for pet to uptake and to ensure the live probiotics that will be able to reach pet's GI tracts in order to make sure that the pet will have the beneficial effects of probiotics.
Let us take a close look of these two critical issues when we apply probiotics to the pets. By understanding these critical issues, we can easily find out why the pet owners experienced the variable effects of probiotics. If we go to a pet store, we may easily find many pet foods do include the probiotics, especially, probiotic fermentation cultures. Interestingly, Canadian scientists used to perform the extensive research survey for 19 commercially available pet foods, which claim to contain probiotics. They reported that no products contained all the listed probiotics, and average bacterial growth only ranged from 0 to 1.8×10 5 CFU/g (Colony Forming Unit over weight, gm. This is the typical measurable unit for microbiologists to present the amounts of living bacteria in defined weights). The publication is available in Can. Vet. J., 2003, 44:212-215. Furthermore, once pets eat the pet foods, pets secreted many different enzymes to help to digest the foods, which are able to destroy the Probiotics viability too. As the foods move down to pet's GI tracts, probiotics have to go through very acidic and high salts environments, especially, in pet's stomach that can be as low as pH 1.0. Most of probiotics will not be able to survive through these harsh environments. In fact the survival percentages of live probiotics is so low that one has to do high numbers of live probiotics for daily oral administration to guarantee the beneficial effects. It is well recognized that the daily oral administration of live probiotics has to be greater than 1×10 10 in human or 1×10 9 CFU in animals to found the beneficial effects of probiotics. If we convert this amount of probiotics in the best available pet foods described by Canadian scientists, the pets at least have to take more than 10 kg of pet food per day to be able to see the probiotics beneficial effects. Combination of far less numbers of probiotics to feed the pets with the pet natural defense systems in GI tracts, we can easily recognize why the variable effects of probiotics are observed by pet owners. Once pet owners realize to feed the pet with right numbers of live probiotics to the pet, the health benefits of probiotics on the pet will be recognized without doubts.
However, since probiotics are biological entities, delivery of sufficient doses is constantly challenged by inherent factors that might limit their biological activity, including the conditions of growth, processing, preservation, and storage. Specifically, loss of probiotic viability occurs at many distinct stages, including freeze-drying of cells during initial manufacturing, feed preparation (high temperature and high pressure), transportation and storage (temperature fluctuations), and after consumption or in gastrointestinal (GI) track (low pH and bile salts). One of the determined factors for probiotics to have beneficial effects is to maintain the high concentration of viable cells for animals and humans to uptake. Although many commercial probiotic products are available as the additive of animal feed and/or as human functional foods, most of them lose the viability during the manufacturing process, transport, storage and animal feed process (Cinto-Cruce and Gould, 2001). Recently, microencapsulation of probiotics using lipids as the carriers has demonstrated the success for improving the probiotics viability (Pacifico et al., 2001). However, there is relatively little information and progress on microencapsulation of probiotics, especially using biopolymers as the microcarriers.
Microencapsulation, extensively used by pharmaceutical, chemical, and food industries to protect precious and/or active ingredients and ensure proper delivery, is limited to the techniques used (emulsion and extrusion) and the composition of microcarriers, including Na-alginate (also in combination with starch, pectin or whey proteins), gum Arabic (also known as gum acacia), and K-carrageenan (also in combination with locust bean gum). Not only each of the systems has its own limitations, these common systems usually suffer from low mechanical stability. For instance, although alginate is the most commonly used polymer due to its simplicity, low cost, and excellent biocompatibility, the low mechanical strength of the gel makes it highly susceptible to decalcifying and acidification. The microencapsulation using biopolymers greatly enhance the benefit of probiotics as healthful ingredients by retaining sufficient viability and bioactivity under harsh processing conditions during animal feed and pet food production. In addition to improving the shelf life stability, the transportation costs of these microorganisms will also be reduced if the resulting microcapsules could be stored under room temperature.
Microbial exopolysaccharides are classified as biopolymers and are widely used in foods, medicines, and industrial products (Marin, 1998). Microbial biopolymers, unlike other carriers, are capable of forming a three-dimensional structure that is stabilized by cross-links connecting junction zones between individual molecules (Lo et al., 2003). In nature, for example, Xanthomonas campestris , a plant pathogen of cabbage, produces xanthan gum as an extracellular slimy material to help the cells attach to their host and to endure environmental stresses. Therefore, application of microencapsulation to bacteria using microbial biopolymers provides a new approach to improve the bacterial viability under harsh environmental conditions.
Studies of GI tract infections have shown that probiotics can modulate the immune response to antigens expressed by GI pathogens (Isolauri 2003). When mice were fed L. acidophilus and/or L. casei prior to oral challenge with Salmonella typhimurium , researchers documented that ˜100% of the probiotic-treated group mice survived S. typhimurium challenge compared to <20% survival in control animals. Anti- Salmonella antibody titers were higher in both the serum and GI tract mucosa of the mice fed L. acidophilus/L. casei (Perdigon et al., 1990). Similarly, oral administration of Bifidobacterium breve stimulated an improved IgA response to cholera toxin in mice (Yasui et al., 1992), and L. rhamnosus GG was shown to increase IgA rotavirus-specific antibody secreting cells in children with acute rotavirus diarrhea (Kaila et al., 1992). Both cellular and humoral immune responses were demonstrated when rotavirus-infected piglets were fed B. lactis HN019 (Shu et al., 2001)
Enhanced antibody responses to ovalbumin were demonstrated in gnotobitic mice fed B. bifidum (Moreaue et al., 1990). This indicates that probiotics could be used to stimulate an antigen-specific mucosal immune response, and to provide increased protection to non-mucosal sites. Significant increases in IgG anti-influenza antibodies were observed when B. breve was fed to mice prior to an oral challenge with influenza vaccine (Yasui et al, 1999). Increased serum IgA titers to Pseudomonas aeruginosa were detected in mice fed with L. casei (Alvaez et al., 2001). IgA, IgG and IgM antibodies against E. coli and rotavirus were found in the feces of piglets fed Bifidobacterium lactis HN019 (Shu et al., 2001). Recently, local cell-mediated immunity by Lactobacillus -feed, E. acervulina infected broiler chickens was demonstrated based on the higher IL-2 secretion and lower E. acervulina oocyst production (Dalloul et al., 2003). However, few or no reports related to immune responses were described for lactic acid bacteria other than Lactobacillus or Biofidobacterium.
Selection through the survival of feces from probiotics-feed chickens.
Strains of lactic acid bacteria differentially stimulate the host immune system. The colonization of the GI tract with probiotic microorganism represents the first step towards establishing a beneficial effect using the introduced bacteria. In order for bacteria to colonize effectively the host, P. acidilactici , it must grow in low pH and bile that represent in the GI tract. The strain selection will be emphasized on the isolation of survival strains from feces collected from P. acidilactici -feed chickens without inoculation of Eimeria . At days 7, 11, 14, 18, and 21, the droppings from P. acidilactici -feed chickens will be collected from three individual chickens. Following the similar procedures performed on the droppings from oocysts production, the droppings will be resuspended and soaked in PBS buffer instead of water. The conventional, microbiological culture for determination of the quantitative numbers of colony formation unites (CFU) will be used to isolate the single isolated bacterial colonies and to correlate with the colonization of P. acidilactici in chickens. For colonization evaluation, a series of dilutions of homogenized droppings will be plate onto different selective media (such as: MRS media for P. acidilactici , Rogosa media for Lactobacillus spp, RCA medium for Clostridium spp. LB media for E. coli ) and incubated in different growth conditions. After completing the collection of CFU, hundreds of single colonies isolated from MRS media will be transferred onto fresh MRS media containing 0.9% bile at pH 2.0, which is regarded as the standard GI tract in humans and animals, for further selection of P. acidilactici . The transfers will be repeated for two more times onto fresh MRS media containing 0.9% bile at pH 2.0, and the survivals of single colony will be further evaluated by pulse-field gel electrophoresis and API biochemical assays for bacterial strains confirmation before bacteria will be made as the glycerol stock and stored at 70° C.
Strains selection through the colonization of cell lines in vitro.
Adhesion of bacteria to the human cell lines Caco-2 and HT29 has been shown to correlate with lactic acid bacterial colonization in animals (Brassart et al., 1998; Tuomola and Salminen 1998). Further selection of strains that are able to grow at 0.9% bile at pH 2.0 will be selected by the co-cultivation of bacteria with the Caco-2 and HT29 cell lines. Determination for bacterial adhesion to Caco-2 and HT29 cell lines will be confirmed by microscopic examination and will be repeated two more times. Bacteria that can grow at 0.9% bile at pH 2.0 and show the adhesion to Caco-2 and HT29 cell lines will be prepared as highly concentrated probiotics at 10 billion/g for chicken feeding in order to do further screening for bacteria with enhanced immune response in chickens.
Strains selection through oral administration of bacteria to E. maxima vaccinated chickens.
To select P. acidilactici strains capable of enhancing the immune response of the colonized host, bacteria that adhere effectively to the cell lines will be re-selected in bacteria-feed and E. maxima vaccinated chickens. These in vitro and in vivo selection methods would yield P. acidilactici strains with enhanced colonization and immune promoting properties in animals. The chickens will be fed with the selected P. acidilactici strain, vaccinated with E. maxima live oocysts, and infected with high amounts of E. maxima sporulated oocysts. The sample collections and the assays for determination of immune responses and disease infection will be the same. The selection cycle will be repeated one more time to confirm the selected strains that have the enhanced immune response properties.
EXAMPLE 1
An eight year old black Labrador hybrid with Beagle and Dalmatian, was fed and observed in Table 1. Symptoms: throws out or daily vomiting, bad body odors, constantly producing and releasing gas with bad odors or flatulence.
Feeding procedure: daily fed a piece of cheese wrapped with a capsule of MITOMAX™, which contains 4 billions CFU of Pediococcus acidilactici and Saccharomyces boulardii , starting from Jun. 21 to Jul. 4, 2004. MITOMAX™ is a trademark of Imagilin Technology, LLC, Potomac, Md. for gelatin encapsulated probiotics.
TABLE 1
***Bad
**Body
odors of
Date
MITOMAX ™
*Throws out
odors
gas release
Jun. 19, 2004
−
Y
+++++
+++++
Jun. 20, 2004
−
Y
+++++
+++++
Jun. 21, 2004
+
N
+++++
++++
Jun. 22, 2004
+
N
++++
++++
Jun. 23, 2004
+
N
++++
+++
Jun. 24, 2004
+
N
++++
+++
Jun. 25, 2004
+
N
++++
+++
Jun. 26, 2004
−
Y
++++
+++++
Jun. 27, 2004
+
N
++++
++++
Jun. 28, 2004
+
N
+++
+++
Jun. 29, 2004
+
N
+++
++
Jun. 30, 2004
+
N
+++
++
Jul. 1, 2004
+
N
+++
++
Jul. 2, 2004
+
N
+++
++
Jul. 3, 2004
+
N
++
+
Jul. 4, 2004
+
N
++
+
*Y: Observation of throwing-outs or vomiting from the dog N: No observation of throw-outs or vomiting from the dog
**Body odors were determined by the average of three people who objectively smelled the dog twice a day. +++++: very strong odors; ++++: strong odors; +++: somewhat strong odors; ++: less strong odors; + some odors.
***Gas released from dogs were observed and the odors were the average of three people; +++++: very strong odors; ++++: strong odors; +++: some what strong odors ++; less strong odors; + some odors
TABLE 1 shows that feeding of a dog daily with probiotics reduced the incidence of vomiting, and reduced odor, in particular, reduced bad body odor, and reduced the incidence of flatulence.
EXAMPLE 2
Eight Chesapeake Bay Retriever dogs aged from 1 to 13 years with different chronic digestive disorders were treated daily by mixing one MITOMAX™ capsule with the morning feeding for 28 days. TABLE 2 shows the results. In TABLE 2 the age of the dogs is in years, the weight is in pounds.
TABLE 2
Initial
Initial
Final
Dog
Sex
Age
Weight
Symptoms
Weight
Outcome
1
M
9
85
lost appetite
85
increased
appetite, firm
stool
2
F
6
75
poor digestion
75
digestion
improved,
firm stool
3
M
5
86
loose stool,
86
firm stool,
diarrhea
no diarrhea
4
F
9
80
poor digestion,
80
digestion and
swallowing
swallowing
difficulty
improved
5
M
13
70
loose stool,
70
firm stool,
diarrhea
no diarrhea
6
F
2
68
lost appetite
68
improved
appetite
7
F
1
60
lost appetite,
—
improved
loose stool,
appetite, firm
diarrhea
stool, no
diarrhea
8
F
9
80
vomiting 2 or 3
80
no vomiting
times a week
TABLE 2 shows that daily feeding dogs of both sexes and a variety of ages with a capsule of probiotics resulted in improvement in digestion, in particular in improvement in appetite, reduction of diarrhea and the improvement in firmness of stools, reduction of swallowing difficulty, and reduction of vomiting.
Microencapsulation of lactic acid bacteria using biopolymers.
Viable lactic acid bacteria and yeasts used in probiotics for pets, such as dogs and cats, are encapsulated and protected by the microbial biopolymers xanthan gum and chitosan. Xanthan gum is a polysaccharide gum which dissolves readily in water with stirring to give highly viscous solutions at low concentrations. It forms strong films on evaporation of aqueous solutions and is resistant to heat degradation. Chitin is a polysaccharide consisting predominately of unbranched chains of N-acetyl-glucosamine residues. Chitosan is deacylated chitin, a polymer often used in water treatment, photographic emulsion, in improving the dyeability of synthetic fibers and fabrics and in wound-healing preparations.
Probiotic microbes were encapsulated with an aqueous solution containing 0.5 to 2.5 percent (weight by volume) xanthan gum and 0.2 to 0.8 percent (weight by volume) chitosan. The pH of the solution was from 2.0 to 7.0. A preferred solution contained 1.25 percent (weight by volume) xanthan and 0.4 percent (weight by volume) chitosan at a pH of 4.15. Viable microbial cells are encapsulated at up to 10 10 colony forming units (cfu) per ml.
Encapsulation of viable probiotic microbes in the mixture of xanthan gum and chitosan has the advantage of protecting the viability of the microbes, of delivering the proper dosage of viable probiotic microbes to the pet or dog which is being fed, and of facilitating the feeding of the probiotic microbes. Dogs and cats do not reject the probiotic microbes when they are encapsulated in a mixture of xanthan gum and chitosan.
Without wishing to be held to this explanation, the inventors suggest the observed efficacy of the chitosan and xanthan gum solution in encapsulation of probiotic microbes is due to the formation of a xanthan-chitosan complex. The mixture of two oppositely charged polyelectrolytes in aqueous solution results in formation of a polyelectrolyte complex due to the electrostatic attraction of oppositely charged polymers. It is postulated that at moderate pH values the xanthan gum is predominately associated with a large number of net negative charges, while chitosan is associated with a large number of net positive charges. The two polymers with opposite net charges therefore bind together forming a stable complex and a strong gel. Relatively high pH values deionize the amino groups on the chitosan with resulting less stable binding between the two polymers and less strong capsule.
FIG. 1 is a graph showing the capsule hardness at pH values from 2 to 8. Capsules were formed as in the preferred process above. Capsule hardness or mechanical strength was measured at a variety of pH values using TA.XT2i, using a 5 kg load cell and a distance of 1 mm. FIG. 1 showed that the hardness of the capsules peaks in the pH range of 3 to 4, and was relatively low at pH 6 to 8. The data of FIG. 1 are consistent with the above theoretical discussion of the formation of a chitosan-xanthan gum complex.
FIG. 2 shows the effect of low temperature on the viability of encapsulated and unencapsulated microbes. Encapsulated and unencapsulated microbes were held for one hour at 0° C. The number of unencapsulated viable microbes declined from about 10 9.3 cfu/ml to about 10 8.3 cfu/ml. The number of encapsulated viable microbes declined from about 10 9.3 cfu/ml to about 10 9 cfu/ml. FIG. 2 shows the protective effect of encapsulation against low temperature.
FIG. 3 shows the effect of high temperature on the viability of encapsulated and unencapsulated microbes. Encapsulated and unencapsulated microbes were held for 150 seconds at 60° C. The number of unencapsulated viable microbes declined from about 10 9 cfu/ml to about 10 7 cfu/ml. The number of encapsulated viable microbes declined from about 10 9 cfu/ml to about 10 8.9 cfu/ml. FIG. 3 shows the protective effect of encapsulation against high temperature.
FIG. 4 shows the effect of low pH on the viability of encapsulated and unencapsulated microbes. Encapsulated and unencapsulated microbes were held from 0 to 60 minutes at pH 2. The number of unencapsulated viable microbes declined from about 10 9 cfu/ml to about 10 5.7 cfu/ml after 30 minutes and to about 10 5.5 cfu/ml after 60 minutes. The number of encapsulated viable microbes declined from about 10 9 cfu/ml to about 10 7.8 cfu/ml at both 30 and 60 minutes. FIG. 4 shows the protective effect of encapsulation against low pH.
Probiotics as alternative medicines against infectious parasitic diseases of broiler chickens
Avian coccidiosis is the major parasitic disease of poultry causing mortality, malabsorption, inefficient feed utilization, impaired growth rate in broilers and reduced egg production in layers (Lillehoj et al., 2004). The most prominent symptom of avian coccidiosis is growth retardation characterized by reduced weight gains or even weight loss in severe cases, causing a major economic impact to the poultry industry (Dalloul and Lillehoj, 2006). Drugs and live vaccines are the two main control measures of disease; however, due to increasing concerns with prophylactic drug use and high cost of vaccines, alternative control methods are needed. For Eimeria -infected-broiler chickens, although the stimulation of antibody production was observed, the increase of cellular immune responses is the key to control the diseases (Dalloul and Lillehoj, 2004). Recent progress in probiotics research demonstrates that live bacteria can influence host humoral immunity against enteric diseases like rotavirus, E. coli , and Salmonella (Isolauri, E. 2003; Majamaa, et al 1995; Perdigon, et al 2001). In order to apply probiotics as an effective alternative medicine against Eimeria -infected broiler chickens one has to show the good effects of both humoral and cellular immunity in probiotics-fed, Eimeria -infected broiler chickens.
Examination of potential toxic effects of probiotics on Eimeria -infected broiler chickens
Day-old broiler chicks were housed in brooders at 15-20 birds per group and fed either control, only commercial feed, or Pediococcus acidilactici containing commercial feed from day one. Five diets were formulated based on Pediococcus acidilactici levels as percentage of basal feed: 0%, 0.01%, 0.05%, 0.1%, and 0.4%. At day ten, all birds except for the control (no Pediococcus acidilactici , no infection) were orally infected with either 5,000 sporulated oocysts of Eimeria acervulina . Bird body weights were taken at 0, 6, & 9 days post infection (dpi) and weight gains were calculated. Fecal materials were collected for 4 days, from 6 to 9 days post infection, in small buckets for oocyst counting.
Differences between experimental treatments were tested by variance analysis (ANOVA) using the statistical program GRAPHPAD INSTAT, a trademark for statistical software owned by GraphPad Software, Inc., San Diego, Calif. Differences were considered significant at a probability P<0.05. Mean values were then compared by the Dunnett Comparison Test.
Table 3A. Effects of Pediococcus acidilactici on growth and on oocysts in the feces from broilers infected with Eimeria acervulina .
TABLE 3
Group
1
2
3
4
5
6
A. Weight gain in grams from 1 to 9 days post
infection with 5,000 Eimeria acervulina
Dose in
0
5,000
5,000
5,000
5,000
5,000
Oocytes
% P.
0
0
0.01
0.05
0.1
0.4
acidilactici
Av. Weight
396
343
362
366
395
382
Gain g.
Std.
45
45
51
58
36
44
Deviation
B. Weight Eimeria acervulina oocyte shedding, above groups.
Ave. × 10 8
0
2.65
1.97
2.39
1.39
2.10
Std.
0.67
0.50
0.27
0.23
0.60
Deviation
Before one can apply any reagents as the potential medicines, elimination of toxic side effects is the crucial before one would apply the reagents for efficacy study. P. acidilactici is a natural microorganisms in GI tracts of animals and humans, and has not been described in literature to have significantly toxic effects. To investigate any potential toxic effects of P. acidilactici on broiler chickens, we fed broiler chickens or E. acervulina -infected chickens 0.01% to 0.4% of P. acidilactici . As shown in Table 3A, no weight loss or bird death was observed from the broiler chickens fed only with P. acidilactici or those infected with E. acervulina and fed with P. acidilactici . Furthermore, the Eimeria -infected broiler chickens fed with mixtures of probiotics- P. acidilactici and Saccharomyces boulardii in the 0.01% and 1.0% groups, and Eimeria acervulina infected groups showed higher body weight gains during the infection period (Table 3A). For the whole process of experiments, we did not see differences in the major organs (livers, hearts, kidneys, spleens) after feeding the chickens with probiotics. These and similar results demonstrated that Eimeria infected broiler chickens showed no detectable morphological differences either fed with P. acidilactici up to 40 folds (ranged from 0.01% to 0.4%) or with mixtures of P. acidilactici and S. boulardii ranging from 0.01% to 1.0%.
To demonstrate that P. acidilactici can be used against Eimeria infected broiler chickens, we fed chickens with/without P. acidilactici and then orally infected them with sporulated oocysts of Eimeria tellena ( E. tellena ). Interestingly, E. tellena infected chickens fed with P. acidilactici showed a reduction of oocysts in a range of 20% to 40% from control broiler chickens ( FIG. 7 ). Similarly, we observed the oocysts reduction either in a range of 30% to 50% from broiler chickens infected with E. acervulina infected and fed with mixtures of P. acidilactici and S. boulardii or in a range of 10% to 20% from broiler chickens infected with E. tellena and fed with mixtures of P. acidilactici and S. boulardii ( FIG. 8 )). These results showed probiotics have the effects on reduction of pathogens or parasites in animals
Stimulation of humoral immune responses on Eimeria -infected, probiotics-fed broiler chickens.
FIG. 5 shows Anti-EtMIC2 antibody response of broilers fed non-probiotic (NOR), 0.1% or 0.2% Mixtures of P. acidilactici and S. boulardii supplemented diets for 21 days (MG0.1 and MG0.2 respectively). Birds were either uninfected or infected with 5,000 E. tennella oocysts at day 12 post-hatch and sera sampled 10 days post infection. Each bar represents the mean±S.D. (N=3). Means lacking common superscripts differ in uninfected or infected chickens (P<0.05).
To assess antibody responses to Eimeria antigen, EtMIC2, one of Eimeria microneme protein genes that have been cloned and characterized at the molecular level (Dalloul et al, 2006) was used in this study. ELISAs were used to determine the antibody production from serum collected from chickens. Induction of antibody response upon ET infection was evident in all infected groups. Moreover, in P. acidilactici -fed birds, significantly (p<0.05) higher serum Eimeria -specific Ab levels were detected in infected birds when compared to those of birds without probiotics ( FIG. 5 ). These results clearly demonstrate that P. acidilactici is able to stimulate humoral immune responses against specific infectious parasites in broiler chickens.
Systemic cellular immune response: Lymphocyte proliferation.
FIG. 6 shows Concanavalin A (ConA) induced proliferation of splenocytes from chickens following treatment with regular, 0.01%, 0.1% or 1.0% M: Mixtures of P. acidilactici and S. boulardii and infection with Eimeria . Birds were infected with 5,000 E. acervulina (EA) or E. tennella (ET) oocysts at day 14 post-hatch. Splenocytes were collected and cultured in the presence of Con A for 24 h. Cell proliferation was measured by [ 3 H]-thymidine assay. Each bar represents the mean±S.D. (N=3). Means lacking common superscripts differ in EA- or ET-infected chickens (P<0.05).
The proliferation responses in splenocytes stimulated with ConA in the birds fed regular or probiotic diets were used to determine systems cellular immune responses against Eimeria in P. acidilactici -fed broiler chickens. In EA-infected birds, splenocytes of the 0.1% group exhibited significant (P<0.05) proliferation rates compared to all other groups including those on the regular and probiotic diets. In the ET-infected groups, 0.01% and 0.1% birds showed significantly (P<0.05) higher splenocyte proliferative responses to stimulation with Con A, with higher (P<0.05) proliferation rates in 0.1% than 0.01% birds ( FIG. 6 ).
FIG. 7 shows fecal oocysts shed by birds infected with E. acervulina (EA). Oocysts were counted in fecal material collected 6-9 dpi with 5,000 E. tennella broiler chickens fed regular (REG), 0.1% (MG0.1) or 0.2% (MG0.2) MG: P. acidilactici -supplemented diets. Each bar represents the mean±S.D. (N=5 cages).
FIG. 8 shows fecal oocysts counted in fecal material collected 6-10 days past infection with 5,000 oocysts E. acervulina (EA) or E. tennella (ET) Broiler chickens were fed regular (REG), 0.01% (M0.01), 0.1% (M0.1) or 1.0% (M1.0) at day 12 post-hatch. M indicates mixtures of P. acidilactici and S. boulardii . Each bar represents the mean±S.D. (N=5 cages).
Probiotics as alternative medicines for dogs with digestive disorders or dogs infected by infectious virus
Applications of probiotics in dogs with digestive disorders
The success of probiotics, MITOMAX™-mixtures of P. acidilactici and S. boulardii , in Eimeria infected broiler chickens led us to perform a field evaluation of canines with digestive disorders. MITOMAX™ is a trademark for probiotics owned by Imagilin Technology, LLC, Potomac, Md. for mixtures of Pediococcus acidilactici and Saccharomyces cerevisiae boulardii ( S. boulardii ) encapsulated in gelatin capsules. The collaborative field evaluations were performed by four veterinarians in three different animal hospitals located in Sao Paulo, Brazil (Table 4). The dogs' body weight ranged from 2 kg to 26 kg, and age ranged from 1 year old to 15 years old. The dogs suffered from different degrees of digestive disorders and were administered either one or two capsules of probiotics, depending on the dog's body weight. Within 14 days of treatment with probiotics, the dogs recovered from the digestive disorders and showed significant improvement. These results clearly show that probiotics have good effects on canines with digestive disorders.
TABLE 4
Field Evaluation of Probiotics on Dogs with Digestive Disorders in
Animal Hospitals of Sao Paulo, Brazil
Symptoms
Length
(D, V, C,
of Pro-
Sex
OC, F, LA)*
biotics
(M
before
treat-
Effects of
Ages
Weight
Or
Probiotics
ment
Probiotics
Name
(years)
(Kgs)
F)
treatment**
(days)
treatment
Fala
9
16
F
D+
4
Recovery OK
Fino
Peinrige
4
10
M
D+, V+, F+
4
Recovery OK
Habil
9
13
F
OC
10
Improved
Beiney
5
12
M
D+, F++
9
Recovery OK
Branea
1
4
F
LA+
4
Improved
Pilly
6
12
M
OC+
9
Improved
Focinha
3
9
M
LA+
4
Improved
Nicole
2
6
F
D+, V+
4
Improved
Togriho
11
24
M
LA+
9
Improved
Tata
10
5
F
D++, F+
9
Recovery OK
Rel
10
25
M
D+
15
Recovery OK
Deigo
Kate
2
6
F
D++++
7
Recovery OK
Toli
15
26
M
D++, V++
4
Recovery OK
Herna
13
4
M
D++
6
Recovery OK
Mylon
13
4
M
D++
14
Recovery OK
Hyuki
10
4
F
D++, V++,
9
Recovery OK
F+, LA+
Pelilico
2
3
M
D+, F+
12
Recovery OK
Drojun
1
7
M
V+, D++
4
Recovery OK
Max
1
2
M
D++++, F++
9
Recovery OK
*D: Diarrhea,
V: Vomiting,
C: Constipation,
OC: Body Odor,
F: Flatulence,
LA: loss Appetite;
++++: very severe,
+++: severe,
++: mild to severe,
+: mild
**Probiotics treatment means oral administrated a capsule of MITOMAX ™-mixtures of P. acidilactici and S. boulardii per day for dog's body weight less than 20 kg, and two capsules of MITOMAX ™ per day for dog's body weight over 20 kg.
Probiotics as alternative medicine to stop bloody diarrhea of parvovirus-infected dogs.
Parvovirus-infected canines develop severe gastrointestinal distress such as vomiting and bloody diarrhea. Without proper treatment, parvovirus-infected dogs can die within a few days. No antibiotics can be applied to cure parvovirus-infected dogs since it is a viral infection. The recovery depends on the canines' ability to develop their own immune systems to fight against virus. This problem is a good candidate for us to apply probiotics to parvovirus-infected dogs. Four dogs diagnosed with parvovirus infection were shown to have bloody diarrhea even after treated with Normosol R, Reglan, Cefazolin, Metronidazole or Ampicillin, +/−Famotidine. Orally administered probiotics included mixtures of P. acidilactici and S. boulardii , and were given to the four dogs for two to three days. Not only did the bloody diarrhea stop, but also all four dogs had solid stool. No recurrence of bloody diarrhea was reported even after being released from hospital for two weeks as they continued the probiotics treatment (Table 5)
TABLE 5
Effects of probiotics on parvovirus infected dogs
Recur-
Condition
Length
Effects
rence
Snap
after
of pro-
of Pro-
of di-
parvo-
standard
biotics
biotics
arrhea
Age
Weight
virus
treat-
treat-
treat-
in 2
Name
(M)
(Lbs)
test
ment*
ment
ment**
weeks
Cali
4
11
Posi-
Bloody
2 days
Diarrhea
no
tive
diarrhea,
stop,
>6 times
solid
per day
stool
Denver
5
14
Posi-
Bloody
3 days
Diarrhea
No
tive
diarrhea,
stop,
>6 times
solid
per day
stool
Flash
12
45
Posi-
Bloody
2 days
Diarrhea
No
tive
diarrhea,
stop,
>6 times
solid
per day
stool
Molie
9
45
Posi-
Bloody
3 days
Diarrhea
No
tive
diarrhea,
stop,
>6 times
solid
per day
stool
#: Performed by Dr. Volkenbourgh, DVM, at Animal Emergency Clinic, Lancaster, CA.
*Standard parvovirus treatment of the animal emergency clinic includes applying Normosol R, Reglan, Cefazolin, Metronidazole or Ampicillin, +/- Famotidine to the parvovirus infected dogs. Some also received hetastarch or a plasma transfusion.
**Probiotics treatment means oral administrated a capsule of MITOMAX ™-mixtures of P. acidilactici and S. boulardii per day
The effects of probiotics on animals and humans are dependent on the viability of probiotics. Similar numbers of viable probiotics were detected from the encapsulated probiotics, P. acidilactici , stored for two years either at room temperature of at 4° C. No significant differences of morphology and body weight were observed by feeding Eimeria -infected broiler chickens with P. acidilactici , varying from 0.01% to 0.4%. Similar results were obtained when broiler chickens infected with E. acervulina or E. tellena were fed with mixtures of P. acidilactici and S. boulardii varying from 0.1% to 1%.
Effects of probiotics, either P. acidilactici or mixtures of P. acidilactici and S. boulardii , on Eimeria -infected broiler chickens were determined by 1) the reduction of oocysts isolated from the fecal samples, 2) stimulation of antibody production and 3) stimulation of proliferation of splenocytes. The clinic evaluation of probiotics clearly demonstrated that orally administrated mixtures of P. acidilactici and S. boulardii has improved the health condition of canines with digestive disorders such as diarrhea, vomiting, appetite loss, and body odor. More importantly, canines suffering from bloody diarrhea caused by parvovirus infection showed recovery after treatment of orally administered mixtures of P. acidilactici and S. boulardii for two to three days. These results demonstrated that probiotics could be used as alternative medicines against infectious diseases.
Suitable probiotic microbes are yeast and lactic acid bacteria. Suitable probiotic bacteria are Pediococcus, Lactobacillus, Bifidobacterium, Streptococcus , and Enterococcus . Suitable yeast is Saccharomyces cerevisiae boulardii . The encapsulated probiotics are effective against gastrointestinal diseases caused by pathogenic bacteria, viruses, fungi, parasites and single-celled organisms. The encapsulated probiotics are effective against hookworms, roundworms, whipworms and tapeworms. The encapsulated probiotics are effective against coccidians, such as Giardia.
Encapsulated probiotics are effective against infectious gastrointestinal diseases in humans when humans with infectious gastrointestinal diseases ingest suitable dosages of encapsulated probiotics. Encapsulated probiotics are effective against infectious gastrointestinal diseases in fish when fish with infectious gastrointestinal diseases ingest suitable dosages of encapsulated probiotics. Probiotics in the form of dry powder are also effective with properties similar to those of encapsulated probiotics.
DRAWINGS
6 Sheets
SEQUENCE LISTING
Not Applicable
IT3 | An exemplary embodiment providing one or more improvements includes feeding animals with probiotic microbes encapsulated in a mixture of xanthan gum and chitosan, or in gelatin, specifically Pediococcus acidilactici and Saccharomyces boulardii . Such encapsulation protects the viability of the probiotic microbes against unfavorable temperatures. An exemplary embodiment providing one or more improvements includes methods of using viable probiotics in therapy of birds and mammals infected with infectious diseases. Probiotics acted as adjuvants in stimulating antibody reaction and stimulated a cellular immunity response. In particular, probiotics were shown to reduce the number of viable oocytes from fecal samples, stimulate antibody production, and stimulate of proliferation of splenocytes in chickens infected with Eimeria . In addition, probiotics were shown to relieve symptoms of parvovirus infection in dogs. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a Continuation application of U.S. Ser. No. 13/829,779, filed Mar. 14, 2013, which claims priority to Provisional Application U.S. Ser. No. 61/717,384, filed on Oct. 23, 2012, all of which are herein incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to mechanisms used in agricultural planting machines for selecting and dispensing individual seeds. More particularly, but not exclusively, the invention relates to air seed meters used to meter seeds from a row unit on agricultural row crop planters and seeders.
BACKGROUND OF THE INVENTION
[0003] An agricultural row crop planter is a machine built for precisely distributing seed into the ground. The row crop planter generally includes a horizontal toolbar fixed to a hitch assembly for towing behind a tractor. Row units are mounted to the toolbar. In different configurations, seed may be stored at individual hoppers on each row unit, or it may be maintained in a central hopper and delivered to the row units on an as needed basis. The row units include ground-working tools for opening and closing a seed furrow, and a seed metering system for distributing seed to the seed furrow.
[0004] In its most basic form, the seed meter includes a housing and a seed disc. The housing is constructed such that it creates a reservoir to hold a seed pool. The seed disc resides within the housing and rotates about a generally horizontal central axis. As the seed disc rotates, it passes through the seed pool where it picks up individual seeds. The seeds are subsequently dispensed into a seed chute where they drop into the seed furrow.
[0005] Early seed meters were comprised of mechanical means of singulating seeds. These meters were constructed such that fingers on the face of the seed disc gripped seeds as they passed through the seed pool, subsequently releasing those seeds as they passed over the seed chute. Although these mechanical seed meters are effective, they are limited in their ability to assure singulation of seeds and are prone to dispensing duplicates (i.e., multiple seeds) and/or failing to dispense at all (i.e., skips or misses). Other mechanical meters use cells in conjunction with brushes to trap seeds within the cavity and release them over the seed chute.
[0006] Systems that are more recent include an air seed meter, e.g., vacuum or positive pressure meters, wherein the mechanical fingers have been replaced by a disc with apertures. A pressure differential is formed across opposite sides of the seed disc, which generates a suction force at the seed cell apertures. As unobstructed seed cells pass through the seed pool, seeds are drawn onto or against the seed cells and remain thereon until the seed cell passes through a region of the housing with a reduced pressure differential. To create this reduced pressure differential region, generally the “vacuum” (i.e., lower pressure) side of the seed disc is exposed to air pressure near, but not always at, atmospheric levels. At this point, seeds are released from the seed cell of the seed disc and into the seed chute. Compared to mechanical meters, air seed meters promote improved singulation across a wider range of speeds. A problem that exists with an air seed meter is that it can be difficult for the suction (negative) force of the seed cell to draw seeds from a stagnant seed pool. Another problem with air seed meters, and specifically the seed disc, is that seeds not released at or near the edge of the seed disc are susceptible to increased ricochet or bounce, thereby negatively impacting seed spacing. For those air seed meters that do release seeds from at or near edge of the seed disc, seeds are sometimes knocked free of the cells on the seed disc by the seed meter housing sidewall because of the close proximity of the housing sidewall to the cell.
[0007] Therefore, there is a need in the art for an improved seed metering system that improves upon attaching seed from the seed pool to the seed disc. There is also a need in the art for a seed meter that retains the advantage of releasing seed from at or near the edge of the seed disk, but yet reduces the likelihood of unintentionally bumping the seed from the disc during rotation.
[0008] Seed spacing in the seed furrow is controlled by varying the rotational speed of the seed disc. Most commonly, seed disc rotation is driven by connection to a common driveshaft. The driveshaft runs horizontally along the length of the toolbar to connect to each row unit, and is driven by a single motor or a ground contact wheel. In this configuration, the planting rate can be adjusted for all row units uniformly by adjusting the rotational speed of the common drive shaft. This can be a tedious task, and an operator is unlikely to adjust the gear ratio as often as necessary to maximize yields. Generally, an optimal overall rate for a given acreage will be selected prior to planting and will be maintained at that rate regardless of soil conditions. Whether using a mechanical or vacuum style seed disc, the seed disc is installed inside of the seed meter using independent fasteners and requires the use of tools to facilitate changing the disc. For example, if a farmer uses the same planter to plant corn and soybeans, he would use a different disc for the respective seed types. With planters continuing to grow in size, and more row units being added, the task of changing seed discs using independent fasteners and tools adds unnecessary burden to changing out seed discs.
[0009] There is thus a need in the art for a method and apparatus for changing the seeding rate of a seed meter to account for varying conditions, while also providing an easy to change or install method for removing and inserting a seed disc of the seed meter and rigidly retaining that seed disc within the seed meter housing.
[0010] As the art of planting progresses, emphasis on the ability of a seed metering system to accurately and consistently distribute seeds to the seed bed grows. Singulation of seeds by seed meters and spacing of seeds along the seed bed is critical in assuring that a farmer or operator is getting the maximum crop yield out of a given acreage of land. If seeds are located too closely together, or in duplicates, they will compete with each other for available nutrients and moisture in the soil, negatively impacting growth. If seeds are located too far apart, or skipped entirely, useful nutrients and moisture will go unused by the growing crops and the farmer will not realize full yield potential of the land. The increased use of GPS and computer software to generate yield maps has provided farmers the information necessary to determine optimal real time seed spacing for each row.
[0011] Thus, there is also a need in the art for a seed meter that allows for quick and easy adjustment to adjust the spacing between seeds planted in a row.
SUMMARY OF THE INVENTION
[0012] It is therefore a primary object, feature, and/or advantage of the present invention to improve on or overcome the deficiencies in the art.
[0013] It is another object, feature, and/or advantage of the present invention to reduce the frequency of duplicate seeds being selected by a single seed cell.
[0014] It is yet another object, feature, and/or advantage of the present invention to provide a seed singulator with adjustable aggressiveness settings to account for different types, shapes, and sizes of seed.
[0015] It is still another object, feature, and/or advantage of the present invention to provide a radially adjustable singulator to quickly and easily adjust the aggressiveness of the singulator.
[0016] It is a further object, feature, and/or advantage of the present invention to provide a removable singulator for use with a seed meter.
[0017] It is still a further object, feature, and/or advantage of the present invention to provide a singulator that includes adjustable blades with ramps thereon, wherein the space between the ramps of the blades provides the aggressiveness of the singulator.
[0018] These and/or other objects, features, and advantages of the present invention will be apparent to those skilled in the art. The present invention is not to be limited to or by these objects, features and advantages. No single embodiment need provide each and every object, feature, or advantage.
[0019] According to an aspect of the invention, an air seed meter is provided. The air seed meter includes a housing including a seed meter side and a vacuum side, a disc mounted in said housing for rotation about an axis and having a plurality of seed cells spaced radially about the axis for retaining seeds, and an adjustable singulator for eliminating seed doubles from said seed cells. The singulator includes two blades adjacent to and at least partially surrounding the seed cells. The blades of the singulator can be simultaneously adjusted such that a first blade is translated radially away from the axis while a second blade is adjusted radially toward the axis, and that the first blade can be also be adjusted radially toward the axis while the second blade is adjusted radially away from the axis.
[0020] According to another aspect of the invention, a singulating mechanism for use with an air seed meter of an agricultural implement is provided, with the singulating mechanism positioned adjacent a seed disc having a radial array of seed cells. The mechanism includes a first blade positioned adjacent an outer edge of the seed cells of the seed disc, and comprising at least one ramp extending toward the seed cells. It also includes a second blade located adjacent an inner edge of the seed cells of the seed disc and comprising at least one ramp extending toward the seed cells. The first and second blades are both adjustable both toward and away from the seed cells to adjust the spacing between the ramps of the first and second blades.
[0021] According to yet another aspect of the invention, a combination seed disc and singulator is provided. The combination includes a seed disc comprising a cylindrical member having a vacuum side and a seed reservoir side, with the seed disc also comprising a radial array of seed cells spaced from an axis. The singulator comprises a first blade including at least one ramp positioned adjacent an outer edge of the seed cells and extending generally toward the axis, and a second blade including at least one ramp positioned adjacent an inner edge of the seed cells and extending generally away from the axis. Also included is a rotary adjustment operatively attached to the singulator such that rotation of the rotary adjustment adjusts the distance between the ramps of the first and second blades by moving at least one of the first or second blades.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a perspective view of a conventional planter row unit with an air seed meter attached thereto.
[0023] FIG. 2 is a side elevation view of the conventional row unit of FIG. 1 .
[0024] FIG. 3 is a perspective view of an embodiment of an air seed meter.
[0025] FIG. 4 is a perspective view of an embodiment of an air seed meter, showing the opposite side of FIG. 3 .
[0026] FIG. 5 is a planar view of an embodiment of the interior of the housing of the seed meter according to the invention.
[0027] FIG. 6 is a front planar view of an embodiment of the vacuum housing of the seed meter according to the invention.
[0028] FIG. 7 is a rear elevation view of an embodiment of the interior of the vacuum housing of FIG. 6 .
[0029] FIG. 8 is a side elevation view of an embodiment of the vacuum side of the seed disc.
[0030] FIG. 9 is sectional view of an embodiment of the seed disc of FIG. 8 .
[0031] FIG. 10 is a perspective view of an embodiment central hub for use with an air seed meter.
[0032] FIG. 11 is another perspective view of an embodiment the central hub of FIG. 10 , shown in operative relation to a seed disc.
[0033] FIG. 12 is a perspective view of an embodiment of the reservoir side of the seed disc.
[0034] FIG. 13 is an enlarged view of a portion of the seed disc of FIG. 12 , showing the seed cells and seed channels.
[0035] FIG. 14 is a perspective view of an embodiment of the seed disc of FIG. 12 including a singulation mechanism in operative relationship.
[0036] FIG. 15 is a perspective view of an embodiment of the singulation mechanism of FIG. 11 .
[0037] FIG. 15 a is a perspective view of another embodiment of a singulation mechanism.
[0038] FIG. 16 is a perspective view of an embodiment showing the face of the singulation mechanism's rotational adjustment.
[0039] FIG. 17 is a view of an embodiment showing the singulation mechanism with the rotational adjustment removed.
[0040] FIG. 18 is a front partial sectional view of an embodiment of the seed disc and a unique drive in operative relations with the housing and other seed meter components hidden for clarity.
[0041] FIG. 19 is a cross-sectional perspective view of another embodiment of a seed meter.
[0042] FIG. 20 is a side elevation view of the reservoir side of the seed disc in FIG. 18 a.
[0043] FIG. 21 is a perspective view of the vacuum side of the seed disc in FIG. 18 a.
[0044] FIG. 22 is a perspective view of the vacuum housing of the seed meter in FIG. 18 a.
[0045] FIGS. 23 a and 23 b are sectional perspective views of an embodiment of the interface between the seed disc and the seed meter housing.
[0046] Before any independent features and embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of the construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. In addition, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] Referring to FIG. 1 , a conventional planter row unit 10 with an air seed meter 5 is shown. The row unit 10 and air seed meter 5 , as shown in FIGS. 1 and 2 , is known in its general aspects to persons skilled in the art. The row unit 10 includes a U-bolt mount 11 for mounting the row unit 10 to a planter frame or tool bar (not shown), as it is sometimes called, which may be a steel tube of 5 by 7 inches (although other sizes are used). The mount 11 includes a faceplate 12 , which is used to mount left and right parallel linkages. Each linkage may be a four-bar linkage, such as the left one 14 shown in FIG. 1 . It is noted that the opposite (right) linkage is generally a mirror image of the linkage 14 shown in FIG. 1 . The double linkage is sometimes described as having upper parallel links and lower parallel links, and the rear ends of all four parallel links are pivotally mounted to the frame 15 of the row unit 10 . The frame 15 includes a support for an air seed meter 5 and seed hopper 16 , as well as a structure including a shank 17 for mounting a pair of ground-engaging gauge wheels 18 . The frame 15 is also mounted to a furrow-closing unit 19 , which includes a pair of inclined closing wheels 19 a , 19 b . The row unit 10 also includes a pair of furrow opener discs 9 , as shown in FIG. 2 .
[0048] FIG. 3 and FIG. 4 represent a seed meter 20 according to an exemplary embodiment of the invention. The seed meter 20 of FIG. 3 and FIG. 4 includes a seed meter housing 21 , which contains the seed disc 22 and central hub 25 . The seed disc 22 and central hub 25 are exposed for illustration purposes, but would normally be concealed behind a vacuum housing 200 attached to the seed meter housing 21 . The vacuum housing 200 , shown in FIG. 6 and FIG. 7 , also includes a vacuum inlet 202 for a vacuum or other air source (not shown), an aperture 204 to allow seed disc central hub 25 to pass through, and attachment means 206 (shown to be keyhole slots) at an outer area of the vacuum housing 200 . The seed meter housing 21 and the vacuum housing 200 may be molded, such that they comprise molded plastic or other rigid materials.
[0049] Seed is conveyed into a reservoir 26 on the seed meter housing 21 via an input tube (not shown) or a seed hopper ( FIG. 1 ). Once in the reservoir 26 , the seed pools adjacent the seed disc 22 near the bottom or lower portion of the seed meter housing 21 and becomes attached to the seed disc 22 as the seed disc 22 is rotated by direct drive 27 . The interior of the seed meter housing 21 without the seed disc 22 is shown in FIG. 5 , which also shows the location of the reservoir 26 inside the seed meter housing 21 . A door 167 , which may be slidable or otherwise movable, may be positioned adjacent the reservoir opening to provide access to the reservoir 26 to aid in emptying or cleaning out the reservoir 26 . FIG. 5 also shows the location and configuration of a singulator 111 , which is used to prevent multiple seeds becoming attached at a single seed cell 54 . The singulator 111 is shown in FIGS. 14-17 . Seeds are then released from the seed disc 22 as they transition through a zone 30 of the seed meter 20 having little to no pressure differential. Seeds are dropped into the seed chute 24 , which delivers them to the furrow.
[0050] The vacuum housing 200 , as shown in FIG. 6 and FIG. 7 , includes a vacuum inlet 202 , which is connected to a vacuum source (not shown), such as a vacuum impeller, via vacuum hoses (not shown). The seed meter housing 21 includes a plurality of bosses 32 disposed along its periphery, as shown in FIG. 3 . The plurality of bosses 32 are configured to extend through the attachment means 206 of the vacuum housing 200 to locate the vacuum housing and, after rotation by the user, restrain it in place against the seed meter housing 21 . The attachment means 206 of the vacuum housing 200 are shown to be keyhole slots, but any other configuration can be used. The vacuum housing 200 further includes a sealing member 208 fitted into a groove on the interior of the vacuum housing 200 . The sealing member 208 contacts the seed flange 51 of the vacuum side of the seed disc 22 (see, for example, FIGS. 8 and 9 ) to define a vacuum chamber 210 in communication with the vacuum inlet 202 . The sealing member 208 is also surrounded by an annular rim 162 of the seed disc 22 to improve suction at the seed cells 54 . As seed cells 54 move into the vacuum chamber 210 , they are placed in fluid communication with the vacuum source. A plurality of apertures 211 in the chamber 210 provide for suction from the vacuum source along the length of the chamber 210 .
[0051] Also mounted to the inside of the vacuum housing 200 is a remnant ejector 212 for the removal of seeds or seed remnants from a seed cell 54 after the seed cell passes the seed chute 24 and is no longer in communication with the vacuum chamber 210 . The remnant ejector 212 is housed within an ejector housing 215 formed integrally with the vacuum housing 200 . However, the ejector housing 215 may also be removable so as to allow different ejectors to be used according to different seed discs and seed types. The remnant ejector 212 interfaces with a series of seed cells 54 from the vacuum side of the seed disc (shown in FIGS. 3 and 8 ). The remnant ejector 212 includes a rotatable wheel 214 with a plurality of punches 216 about its periphery to remove seeds, seed debris, or other remnants remaining in a seed cell 54 after it passes the seed chute 24 . The remnant ejector 212 is spring-biased towards the seed disc 22 and moves synchronously with the seed disc 22 as it is rotated, i.e., the rotation of the seed disc 22 rotates the wheel 214 of the remnant ejector 212 . Furthermore, the remnant ejector 212 is rotatable about legs 218 to allow the ejector to move relative to the biasing spring, which aids in pressing the punches 216 of the wheel 214 to remain biased against the seed cells 54 of the seed disc 22 .
[0052] FIG. 8 illustrates the vacuum side of the seed disc 22 . The seed disc 22 is substantially cylindrical and has opposing sides—a vacuum side shown in FIGS. 3 and 8 , and a reservoir side, which contacts a pool of seed ( FIG. 12 ). It should be noted that the “vacuum side” generally refers to the side of the disc 22 that will be adjacent the vacuum source. The seed disc 22 comprises a molded plastic or other rigid material. The seed disc 22 has a cross-sectional profile as shown in FIG. 9 . The cross-sectional profile of the seed disc 22 shows at least two zones on the seed disc 22 . The first zone is a generally flat seed flange 51 located at or near the outer radius of the seed disc 22 . A series of seed cells 54 located at the seed flange 51 comprise apertures extending from the vacuum side to the reservoir side, and are spaced radially about the circumference of the seed disc, which is generally a circle. The aperture of the seed cells 54 may be larger on the vacuum side of the disc 22 and narrow through the disc 22 such that the negative pressure on the seed side of the disc 22 is increased. Alternatively, a single-sized aperture may form the seed cell 54 . The seed flange 51 also includes an annular rim 162 extending radially outward from the plurality of seed cells 54 and which will be described later in further detail. Although in the embodiment shown in FIG. 8 a single seed cell circle is shown with seed cells 54 being positioned at an equal radius, one skilled in the art may also appreciate that seed cells could be staggered about multiple circles to create an alternating pattern. It should also be appreciated that the spacing and size of the seed cells 54 may be changed from the illustrated embodiments to accommodate different seed types and planting methods. The present seed disc and seed cells are not to be limited to the embodiments shown and described.
[0053] A second zone 52 is shown by the cross-sectional profile of the seed disc 22 . The second zone is contoured and located radially inward of the seed flange 51 . The second zone 52 includes a cylindrical internal flange 55 . The internal flange 55 is formed substantially perpendicular to the seed flange 51 and is substantially concentric with the center axis of the seed disc 22 . The interior sidewall of the cylindrical interior flange 55 includes four keyways 53 running longitudinally through the interior flange 55 and spaced evenly about the inner circumference of the flange 55 . The cross-section of the keyways 53 is substantially similar to the external profile of the hub protrusions 61 as shown in FIG. 10 . While four keyways are shown in the figures, it should be appreciated that generally any number of keyways are contemplated for use with the seed disc 22 of the exemplary embodiment. When more or less keyways are used with a seed disc, the keyways can be radially spaced around the axis of the disc, or can otherwise be positioned to align with at least as many hub protrusions 61 for connecting the hub to the seed disc.
[0054] The seed disc 22 can be fixed within the seed meter 20 without the use of fasteners or tools by inserting the central hub 25 of the seed meter housing 21 through the aperture 56 created by the inner flange 55 of the seed disc 22 . The keyways 53 of the inner flange 55 are shaped and aligned at 90-degree intervals to receive the protrusions 71 of the hub 25 (see, e.g., FIG. 10 ). With the central hub 25 inserted through the inner flange 55 , the protrusions will emerge from the keyways 53 . The hub 25 can then be rotated in the direction shown by the embossed arrows 57 (see, e.g., FIG. 8 ), while the seed disc 22 is restrained, such that the protrusions 71 will engage recesses or notches 81 on the rim of the interior flange 55 of the seed disc 22 , as shown in FIG. 11 . The seed disc 22 could also be rotated while the hub 25 is restrained to lock and unlock. The central hub 25 slidably mounts to a first end of a shaft 40 to fix the position of the seed disc 22 within the seed meter housing 21 . The central hub 25 is retained in place by an upper roll pin 42 passing through an aperture on the shaft 40 and lower dowel pin, located on the shaft 40 , which may otherwise be the protrusions 71 of the hub 25 . The second, opposite end of shaft 40 is rotatably and axially coupled to an integrated shaft bearing. The shaft bearing (not shown) may be a plain bearing, such as generally any cylindrical sleeve made of a low friction material, a rolling-element bearing, which uses spheres or small cylinders that rotate or roll between a shaft and the mating parts to reduce friction and allow much tighter mechanical tolerances, or a water pump-style bearing. The shaft bearing is positioned in a cavity 44 , as shown FIG. 4 . It should be appreciated that when other numbers of keyways 53 are used to aid in attaching the seed disc 22 to the seed meter 20 , the keyways may be located at other angles, such that the disc 22 or hub 25 can be rotated more or less to engage the protrusions with the recesses.
[0055] Turning now to the reservoir side of the seed disc 22 , which is shown in FIG. 12 , a plurality of recesses or channels 91 are shown formed in the seed flange 51 . On the reservoir side of the seed disc 22 , the seed flange 51 includes a portion extending from the face of the disc 22 and including an inner lip 96 and an outer chamfer 94 . The outer chamfer 94 may be beveled or other angular in relation to the face of the seed disc 22 . FIG. 13 shows an enlarged view of these recesses or channels 91 . A recess or channel 91 is present for and respectfully aligned to a seed cell 54 . The recess or channel 91 is positioned substantially forward of its corresponding seed cell 54 with respect to the rotational direction (as shown by the arrow 93 of FIG. 12 ) of the seed disc 22 during operation and provides agitation of seed in a seed pool when the seed disc 22 is rotated. The channel 91 is oriented at an oblique angle with respect to the radius line that passes through the center of corresponding seed cell 54 . This angle directs seed radially outward and rearward with respect to the rotational direction 93 of the seed disc 22 during operation, such that seed is guided towards the seed cells 54 . The channels 91 as shown are substantially rectangular in shape, but could be also comprise an oval or any other shape that would aid in the directing of seed towards seed cells 54 . It should also be appreciated that the shape and configuration of the channels can aid in loosening seeds in the reservoir, while also guiding them towards the seed cells 54 . Furthermore, the channels or recesses include a ramped portion 97 generally adjacent the seed cell 54 , which is used to position the seed at the seed cell 54 during rotation of the seed disc 22 .
[0056] Therefore, the channels 91 of the seed disc 22 provide numerous advantages. As the channels 91 are generally recessed areas separated by wall-like portions, they will increase agitation of the seed pool to promote the movement of the seeds from the seed pool. The recessed channels 91 will also provide a direct path from the seed pool to the seed cells 54 , which will promote good adhesion between the seed and the seed disc 22 at the seed cells 54 . This will aid in increasing the accuracy of the seed meter by increasing the likelihood that a seed will be adhered to the seed cell 54 . As the channels 91 are formed integrally with the seed disc 22 , they can be configured and numbered to match generally any number of seed cells 54 and can be oriented or sized to best match with any type of seed. In the alternative, one single channel 91 size and orientation may be configured such that it is usable with all types of seed.
[0057] In addition, the reservoir side of the seed disc 22 will include an outer chamfer 94 and an extension surface 95 , which extends generally from the outer chamfer 94 to the annular lip 162 on the periphery of the seed disc 22 . The outer chamfer 94 essentially forms a “false edge” of the seed disc 22 , to better position the seed at or near the edge for better consistency during release of the seed into the chute 24 . During rotation of the seed disc 22 , and after the seeds have adhered to the seed cells 54 , the disc 22 will continue to rotate until a seed passes the zone 30 of the seed meter 20 with little to no pressure differential. At this location, the outer chamfer 94 will be directly adjacent the outer wall of the seed meter housing 21 , which positions the seed and seed cell 54 at the false “outer edge” of the seed disc 22 . Thus, the seed will become disengaged from the seed cell at the outer edge, which will decrease the likelihood of ricochet or bounce as the seed passes through the chute 24 , thereby increasing seed spacing consistency. The length of the extension surface 95 will vary based upon factors such as the amount of offset 161 , the type of seed, how close the seed cells 54 need to be to the “edge”, as well as other factors. The creation of the “false edge” provides for the seed to be released at or near the “edge” of the seed disc 22 , while still providing enough suction as the disc 22 passes adjacent the seed pool, as will be discussed below.
[0058] In situations where duplicate seeds may be drawn onto or against a single seed cell 54 , a singulator 111 , such as that shown in FIGS. 5, 14, 15, and 17 can be used. The singulator 111 is configured to remove the excess seed(s) from the seed cell. The singulator 111 is mounted at and operatively connected to the seed meter housing 21 such that a first blade 112 (shown most clearly in FIG. 17 ) and a second blade 113 is adjacent to the reservoir side face of the seed flange 51 and the seed cells 54 . The blades are spaced from the face of the seed disc 22 , as well as the flange 51 and seed cells 54 . The blades 112 , 113 may be configured such that they are on opposite sides of the seed cell circle. The singulator 111 is biased towards the axis of the seed disc 22 and/or seed meter housing 21 . The biasing towards the axis of the seed disc 22 and/or seed meter housing 21 may be provided by a spring, gravity, or other tension member, such as by attaching the singulator 111 by a wire to the seed meter housing 21 . The singulator 111 is configured to have a fixed, curved rim portion 119 that at least partially surrounds the annular rim 162 of the seed disc, which aids in positioning the singulator 111 adjacent the seed cells 54 .
[0059] The first blade 112 is positioned adjacent to the backside of the curved rim 119 , i.e., the side furthest from the seed disc 22 , and radially outward of the seed cell 54 circle. The first blade 112 includes an inner edge with a first set of ramps 115 and a generally curved profile similar to the circumference of the seed cell circle. Biasing the singulator 111 , including first blade 112 , generally inward towards the axis, aids in keeping the blade 112 , and thus, the ramps 115 , at the outer edge of the seed disc 22 to position the blade 112 and ramps 115 adjacent an outer area of the seed cells 54 . This aids in removing additional seeds at the seed cells 54 so that one seed is positioned at a seed cell 54 .
[0060] The second blade 113 is spaced from the first blade 112 and is positioned radially inward of the seed cell circle 54 . The second blade 113 includes an inner edge (closest to the seed cell circle) with a second set of ramps 116 . It should be appreciated that the singulator 111 could have other ramp configurations for different seed types and the profile of the blades are not to be limiting to the exemplary embodiment. For example, smaller seeds such as a soybean seed may need less aggressive singulation and, therefore, fewer or smaller ramps can be used than for larger seeds like corn. It should also be appreciated that first blade 112 and second blade 113 could be comprised of a plurality of individual ramp assemblies, capable of moving independent of or in relationship with one another. For instance, a first ramp on first blade 112 could move independent of or in relationship with a second ramp on first blade 112 , or a first ramp on first blade 112 could move independent of or in relationship with a first ramp on second blade 113 .
[0061] The first blade 112 and second blade 113 are attached to first and second carriages, 121 and 122 . In addition, the first and second blades 112 , 113 may be formed integrally with the carriages 121 , 122 . The blades 112 , 113 may be attached to the carriages 121 , 122 such that they can be replaced after wear and tear, or due to a change in the type of seed being using with the system. Therefore, screws, or other temporary attachments may be used to at least temporarily attach the blades to the carriages.
[0062] The first and second carriages, 121 and 122 , are manipulated via a rotary adjustment 114 in a manner such that the first blade 112 adjusts radially outward as the second blade 113 simultaneously adjusts radially inward or vice versa, thus changing the width of the seed path between the first and second blades 112 , 113 for the seed cells 54 to pass through. The second blade 113 is connected to the rotary adjustment 114 via a cam or other mechanism that converts the rotational movement of the rotary adjustment 114 to a translational movement of the first 112 and/or second blade 113 . Thus, the second blade 113 (and/or first blade 112 ) moves generally towards or away from the first blade 112 in a longitudinal manner as the rotary adjustment is rotated. For example, the blades 112 , 113 may be slidably connected such that the blades slide along guides, slots, or notches in the singulator 111 . However, it is not required that both carriages, and thus, both blades move with rotation of the rotary adjustment 114 . For example, it is contemplated that only one of the blades move when the rotary adjustment 114 is rotated to either widen or narrow the distance between the blades, and thus, the ramps on the blades. Furthermore, the curved rim 119 remains fixed while the first blade 112 moves to ensure positioning of the singulator 111 adjacent the seed cells 54 .
[0063] A wider seed path typically allows for less aggressive singulation, i.e., less contact by a ramp 115 , 116 with a seed(s) in the seed cell 54 . A narrower seed path typically creates more aggressive singulation, i.e., more contact by a ramp 115 , 116 of a seed(s) in a seed cell 54 . The level of aggressiveness is determined based on a number of factors, including, but not limited to, seed size, rate of seed dispensing, type of seed, and/or the amount of suction present at the seed cell 54 . However, the singulator 111 is generally configured such that only one seed is drawn onto or against the seed cell 54 and any other seeds drawn onto or against the seed cell 54 are knocked off into the seed pool. The slot 28 in the housing allows an operator to easily access the rotary adjustment 114 , so as to adjust the width of the seed path between the first and second blades 112 , 113 without removal of any parts. This allows the singulator 111 to be used in the seed meter 20 with a variety of types of seeds, e.g. corn, bean, etc., while also allowing quick and easy adjustment for the width of the path between the blades.
[0064] FIG. 16 illustrates a view of the face of the rotary adjustment 114 . On the face are cam grooves 131 and 132 . These grooves 131 , 132 vary in radial distance from the center axis 134 of the rotary adjustment 114 . Rotating the rotary adjustment 114 causes the first and second carriages 121 , 122 (and thus, first and second blades 112 , 113 ) to move in a linear direction either toward or away from the axis of the seed disc 22 , which changes the width of the path between the blades 112 , 113 such that the blades can be used with different types and sizes of seeds. With the carriages restricted to linear motion, the engagement of the carriage protrusions, 141 and 142 , with the cam grooves, 131 and 132 , causes the carriages to change position relative to the rotation of the rotary adjustment 114 . The carriages 121 , 122 , and protrusions 141 , 142 can be seen in FIG. 17 . However, as noted above, when only one of the blades 112 , 113 is to be moved, only one set of grooves can be included on the face of the rotary adjustment 114 such that rotation thereof causes the protrusion in engagement with the groove to move linearly.
[0065] The singulator 111 can also be a removable cartridge from the seed meter housing 21 to allow the singulator 111 to be repaired, replaced, cleaned, adjusted, etc. The singulator 111 includes attachment means 117 , such as feet extending generally from the bottom side of the singulator 111 . The feet 117 , which are shown for exemplary purposes, are configured to fit into slots 118 (see FIG. 5 ) formed integrally with or attached to the inside of the seed meter housing 21 . Therefore, to remove the singulator 111 , a set of snaps on the singulator are disengaged, allowing the singulator to be rotated and the feet 117 to remove from the slots 118 in the seed meter housing 21 , and removing the rotary adjustment 114 through an aperture in the seed meter housing 21 . To replace the singulator 111 , the feet 117 are positioned in the slots 118 , and the rotary adjustment 114 is positioned through the aperture in the seed meter housing 21 to provide access for a user to adjust the spacing between the first and second blades 112 , 113 . Furthermore, any number or configuration of snaps or other members may be added to the singulator body and/or housing to aid in retaining the singulator in place in the seed meter housing 21 .
[0066] In another embodiment of a singulator mechanism, which is shown generally in FIG. 15 a , the singulator 111 does not include a set of snaps and feet 117 , but instead is secured to and within the seed meter housing 21 by a tension member 120 , such as a flat spring. In this manner, the singulator 111 can be removed from the housing by sliding clips 120 a upwardly and then towards the user with respect to boss 120 b . Singulator 111 can then be removed from the seed meter housing 21 for repair, replacement, cleaning and adjustment. In other embodiments using the tension member 120 , protrusions may extend from the interior of the seed meter housing 21 , with apertures of the tension member 120 simply snapping to or otherwise fitting on the protrusions to at least temporarily secure the singulator 111 to the seed meter housing 21 .
[0067] FIG. 18 provides an illustration of the interaction between the unique drive 27 and the seed disc 22 according to an exemplary embodiment of the invention. A portion of the seed meter 20 has been sectioned away to show internal components of the assembly. As shown in FIG. 18 , the unique drive 27 is mounted externally to the seed meter housing 21 such that an output shaft 154 of the drive 27 protrudes through at least a portion of the seed meter housing 21 perpendicular to and adjacent the face of the reservoir side of seed disc 22 . An external gear 153 is mounted on or otherwise forms a portion of the output shaft 154 . Integrally molded into, or attached to in some embodiments, the reservoir side of the seed disc 22 is an internal gear feature 152 . Said internal gear 152 and said external gear 153 are positioned such that their matching gear teeth engage each other. This engagement allows direct control of the rotational speed of the seed disc 22 via control of the unique drive's 27 rotational output speed of the output shaft 154 . In an exemplary embodiment, the unique drive 27 is powered by an electric motor 151 , but one skilled in the art may appreciate that the unique drive could also derive its power from a pneumatic or hydraulic rotary motor, as well as any other type of rotary motion, including but not limited to, mechanical, cable drive, or chain.
[0068] In another embodiment of a seed meter, as shown in FIG. 19 , the unique drive 27 a is mounted externally to the vacuum housing 200 a such that the output shaft 154 a protrudes through the vacuum housing 200 a substantially perpendicular to and adjacent the face of the vacuum side of the seed disc 22 . An external gear 153 a is mounted on or otherwise forms a portion of the output shaft 154 a . Integrally molded into the vacuum side of the seed disc 22 a is an internal gear feature 152 a . The internal gear feature 152 a may also be a separate element that is attached to an internal ring or flange of the vacuum side of the seed disc 22 a . Said internal gear feature 152 a and said external gear 153 a are positioned such that their matching gear teeth engage each other such that the output of the unique drive 27 a rotates the seed disc 22 a . FIGS. 20-22 further depict the seed disc 22 a and vacuum housing 200 a of the modified embodiment.
[0069] The control of the speed of the unique drive 27 , 27 a , and thus seed disc 22 , 22 a , allows for the spacing of the seeds during planting to be better controlled. As noted, the rotational velocity of the seed disc 22 , 22 a in relation to the speed of travel of the tractor or other equipment aids in controlling the distance between seeds in a row. Therefore, the addition of the unique drive 27 , 27 a allows an operator to control the distance by simply adjusting control of the drive 27 , 27 a . For example, an operator in a tractor could adjust the rotational speed via remote or other control interface such that the distance between seeds could be adjusted during planting. This can result in significant time savings, as the operator does not have to stop planting to adjust seed rate of the meter, thus allowing a field to be efficiently planted with varied planting conditions.
[0070] Referring to FIGS. 23 a and 23 b , an enlarged and sectional view of the seed meter 20 is shown detailing the interface between the seed disc 22 and the seed meter housing 21 . In certain areas, an offset portion 161 of the outer sidewall 163 is provided to be eccentric with the outer circumference (e.g., annular rim 162 ) of the seed disc 22 . A relief member 165 , which is also shown in FIG. 5 , covers the space created by the offset portion 161 between the seed cell 54 of the seed disc 22 and the bottom edge of outer sidewall 163 . For example, as shown in FIG. 23 a , the offset portion 161 is eccentric with the seed disc 22 at the loading zone 166 , i.e., the area of the seed meter 22 where the seed pools and is agitated prior to being drawn onto or against a seed cell 54 . The area created by offset portion 161 and covered by the relief member 165 gives the seed additional room to move about and be drawn onto or against the seed cell 54 , which reduces the likelihood of the seed being knocked free from the seed cell 54 by the seed meter housing 21 during rotation of the seed disc 22 . The relief member 165 also aids in orienting the seed in the seed cell 54 such that a greater surface area of the seed will fit in the cell 54 to provide the strongest suction on the seed at the cell 54 .
[0071] The relief member 165 essentially creates a false outer wall of the seed meter housing 21 . As mentioned above and shown best in FIGS. 12 and 13 , the reservoir side of the seed disc 22 will include an outer chamfer 94 and an extension 95 that ends at the annular rim 162 of the seed disc 22 . As mentioned above, the outer chamfer 94 and extension 95 creates a false edge for the seed disc 22 , which allows the seed cells 54 to be positioned generally at the outer edge of the false edge. While the false edge created by the outer chamfer 94 and extension 95 aids in releasing seed, they can make it difficult for the seed to attach to a seed cell 54 at the seed pool due to the decreased suction at the outer edge of the seed disc 22 . The offset portion 161 and relief member 165 counteract this by creating a “false wall”. The so-called false wall created by the relief member 165 will extend from the outer chamfer 94 to the outer wall of the seed meter housing 21 . The width of the false wall (relief member 165 ) will make it appear as though the seed is being attached at a location further inward on the seed disc 22 , with the relief member providing a barrier to create more suction at the seed cell 54 to increase the consistency of seed attaching to the seed cells 54 . The relief member 165 and offset 161 can extend to the entrance of the singulator 111 , which is used to ensure that only one seed is positioned at each seed cell 54 .
[0072] An air seed meter for dispensing seed in a field has been provided. The exemplary embodiments shown and described contemplate numerous variations, options, and alternatives, and are not to be limited to the specific embodiments shown and described herein. For example, the improvements described herein are equally applicable to other meters, such as positive-air meters like that disclosed in U.S. Pat. No. 4,450,959 to Deckler, which is incorporated herein by reference in its entirety. The foregoing description has been presented for purposes of illustration and description, and is not intended to be exhaustive list or to limit the exemplary embodiment to precise forms disclosed. It is contemplated that other alternative processes obvious to those skilled in the art are considered to be included in the invention. | A seed metering system, for use on a row crop planter, selects individual seeds from a seed reservoir and dispenses the seeds singularly at a controlled rate. A direct drive seed metering system includes a seed disc having a plurality of suction apertures with a recessed pocket adjacent to an aperture. The recessed pockets act to agitate seeds in the seed reservoir and to direct seed flow towards the apertures. A seed path relief system provides for allowing the placement of the seeds such that they are released from an outer edge of the seed disc. An adjustable seed singulator is mounted adjacent to the face of the seed disc where inner and outer blades are adjusted radially to compensate for the singulation of various seed sizes and shapes. The seed disc is driven via engagement of an internal gear with the external gear of an independent drive motor. | 0 |
INCORPORATION BY REFERENCE
[0001] This application claims the benefit of U.S. Provisional Patent Application 60/370,628 filed on Apr. 4, 2002 and entitled “Simplified Flight Track Display System” and is expressly incorporated herein, in its entirety, by reference.
BACKGROUND INFORMATION
[0002] There may be multiple reasons for individuals that live in the vicinity of an airport to desire to know the flight paths of planes in the area. For example, an individual may notice a plane that is flying a path that is not recognized by the individual (e.g., normally a plane on approach to the airport does not fly directly over the house, etc.). A particular plane may be flying low and causing a noise nuisance and/or the plane may be at or near the normal altitude, but is still causing an excessive amount of noise. A particular plane may make a maneuver that is questioned by the individual. A person may be looking to buy a house in a certain neighborhood and wants to research the flight paths over that neighborhood. These are only a few examples of the usefulness of flight path information and there are many other reasons why the flight paths of planes need to be known to private individuals. In addition, it is difficult to visually ascertain the true altitude and flight path of an aircraft.
[0003] However, it is very difficult for individuals to determine information associated with these flight paths even though most of the information associated with the flights is publically available information based on Federal Aviation Administration (“FAA”) and airport records. In For example, if an individual wanted to make a complaint about noise because of an airplane, the individual generally would like to be able to give some specifics about the airplane such as the general vicinity of the airplane, the altitude, the type of airplane, the airline, etc. But the average person who is not intimately familiar with airplanes and flight information cannot tell this information by looking up at the plane. The individual could go to the airport, the airport authority or the local FAA office and request the records, but this is difficult and time consuming. A simplified manner of tracking flights and flight paths that is available to the general public is needed to address issues such as described above.
SUMMARY OF THE INVENTION
[0004] A system, comprising a data receiving arrangement to receive target data points from a data feed arrangement, each target data point including data corresponding to a location of a target aircraft and additional information on the target aircraft, a data analyzing arrangement to analyze the target data points and store each target data point in a target flight record, the target flight record corresponding to the target aircraft a data generation arrangement to generate a flight track for the target aircraft using the data stored in the target flight record and a data distribution arrangement to organize the flight track and the additional information into a displayable file and distribute the file to users of the system, wherein the displayable file is displayed on a single graphical user interface including the flight track and the additional information.
[0005] In addition, a method, comprising the steps of collecting target data points corresponding to data for target aircrafts, storing each of the target data points in a target flight record, wherein each target flight record corresponds to one target aircraft and each target data point includes data corresponding to a location of the one target aircraft and additional information on the one target aircraft, creating flight tracks from each of the target flight records and creating a displayable file including the flight track and the additional information, wherein the displayable file is displayable on a single graphical user interface.
[0006] Furthermore, a system, comprising a system server collecting target data points corresponding to data for target aircrafts, storing each of the target data points in a target flight record, wherein each target flight record corresponds to one target aircraft and each target data point includes data corresponding to a location of the one target aircraft and additional information on the one target aircraft, creating flight tracks from each of the target flight records and creating a displayable file including the flight track and the additional information, wherein the displayable file is displayable on a single graphical user interface and a web server to distribute the displayable file to users of the system.
BRIEF DESCRIPTION OF DRAWINGS
[0007] [0007]FIG. 1 shows an exemplary system according to the present invention;
[0008] [0008]FIG. 2 shows an exemplary process for the processing of the flight information received by the FTDS System server according to the present invention;
[0009] [0009]FIG. 3 shows an exemplary display screen that may be generated by the FTDS system server and transmitted to the users via the web server software according to the present invention;
[0010] [0010]FIG. 4 shows a second exemplary display screen that may be generated by the FTDS system server and transmitted to the users via the web server software according to the present invention;
[0011] [0011]FIG. 5 shows an exemplary display screen that may be generated by the FTDS system server in response to a user's replay request according to the present invention;
[0012] [0012]FIG. 6 shows a second exemplary display screen that may be generated by the FTDS system server in response to a user's replay request according to the present invention;
[0013] [0013]FIG. 7 shows an exemplary display screen that may be generated by the FTDS system server which has a wider zoom display according to the present invention.
DETAILED DESCRIPTION
[0014] The present invention comprises a simplified flight track display system (“FTDS”) for delivery via a communication network which may be, for example, the Internet, a corporate intranet, etc. The information that is provided to the users (e.g., via a graphical user interface) may include airplanes and other aircraft and their relevant tracks superimposed on a graphical map, such as those created by U.S. government Tiger mapping service or the Microsoft Corporation. For more information on the Tiger mapping service see the domain link http://tiger.census.gov/cgi-bin/mapbrowse-tbl. For more information on the maps created by the Microsoft Corporation see the domain link www.microsoft/mappoint.net. The exemplary embodiment of the present invention is described as a web based system. However, those of skill in the art will understand that there may be any number of other manners of implementing the present invention in embodiments that are not web based.
[0015] [0015]FIG. 1 shows an exemplary FTDS system 1 according to the present invention. The data needed to create the flight tracks may be obtained from a data feed arrangement 100 . The data feed arrangement 100 may be, for example, the PASSUR™ System sold by Megadata Corporation of Bohemia, N.Y., the AD data set which available for resale from the FAA etc. The data feed arrangement may be one of these systems or a combination of these systems depending on the amount and type of information to be provided on each flight track. The stream of data from the data feed arrangement 100 may consist of target data points. Each target data point may include information about a flight being tracked. Each target data point may include data on the flight, for example, a track identification, the time (e.g., UNIX time), the x-position, the y-position, altitude, x-velocity component, y-velocity component, z-velocity component, the speed, the flight number, the airline, the aircraft type, etc.
[0016] Throughout this description the convention will be maintained that each discrete set of data received for a particular flight by the FTDS system server 120 from the data feed arrangement 100 will be called a target data point. Examples of the information included in a target data point are described above. The target data points for an individual flight will be combined by the FTDS system server 120 into a target flight record and when this term is used it should be understood to mean all the target data points for each individual flight track. It should also be understood that the target flight record may include additional information over and above the combination of the target data points for an individual flight. For example, the target flight record may contain specific data used to display the track and indexing information to maintain the data from the target data points in the correct order. The term target is generally used to describe a flight (or aircraft) which is to be tracked. Throughout this description the airplanes are used as exemplary targets, but other aircraft may be used as well, e.g., helicopters. The term flight track is used to describe both the data associated with a particular flight and the graphical manifestation of that data as the icon superimposed on the map and the corresponding flight information data display.
[0017] The data which is input into the FTDS server 110 from the data feed arrangement 100 may be updated based on the type of system used for the data feed arrangement 100 . For example, PASSUR™ System provides real-time data updates at short time intervals (e.g., every 4.6 seconds). Whereas, the ASD data set is updated at a slower interval of 1-4 minutes. Those of skill in the art will understand that a single sweep of the radars associated with the data feed arrangement may produce a plurality of target data points depending on the number of aircraft in the range of the tracking radar. As will be described in greater detail below, the FTDS server 110 will receive the target data points from the various sources and combine and organize the data into a coherent and easy to use flight tracking system. Some data feed arrangements 100 such as the PASSUR™ System provide the input data using a track smoothing process. However, other data feed arrangements 100 may not provide such smoothed data and it is not required to implement the present invention.
[0018] The data feed arrangement 100 is connected to the FTDS server 110 , which may include, for example, the FTDS System server 120 software and web server 130 software. The connection between the data feed arrangement 100 and the FTDS server 110 may be, for example, a one way socket connection providing a serial stream of target report data, e.g., the target data points described above. The one way socket connection may be preferred to prevent users of the FTDS system 1 from corrupting the data contained in the data feed arrangement 100 . However, there may be circumstances where a two way connection between the data feed arrangement 100 and the FTDS server 110 is desirable. The target data points may be transferred to the FTDS server 110 using any standard data format, for example, an ASCII format, a text format, etc.
[0019] The FTDS server 110 maybe, for example, a standard PC based server system running an operating system such as LINUX. Those of skill in the art will understand that any computing platform may be used for the FTDS server 110 . As the FTDS system server 120 software receives the target data points, it processes and analyzes the data to create flight tracks for the aircraft in the target area. Each target data point, as it is received by the FTDS system server 120 software, is filtered to check whether it is associated with a currently displayed flight track. If the target data point is associated with a previously displayed flight track it is added to the target flight record for that target. If the received target data point does not belong to a currently displayed flight track, the FTDS system server 120 software may start a new target flight record for a new flight track.
[0020] [0020]FIG. 2 shows an exemplary process 10 for the processing of the flight information received by the FTDS system server 120 . In step 15 the FTDS system server 120 receives the target data points input data from the data feed arrangement 100 as described above. In step 20 , the FTDS system server 120 determines whether each of the newly received target data points is associated with a current flight track, i.e., whether there is a target flight record with which the target data point is associated. If the target data point is not associated with a current target flight record, the process continues to step 30 where the FTDS system server 120 creates a new target flight record associated with this flight track.
[0021] If the target data point is associated with a current target flight record (step 20 ) or the FTDS system server 120 created a new target flight record (step 30 ), the process continues to step 25 where the target data point is added to the appropriate target flight record. The process then continues to step 35 where the FTDS system server 120 processes the new data to update the flight track for the target flight. The processing of the data to create the flight track will be described in greater detail below and exemplary displays of flight tracks will be shown and desribed.
[0022] The data for the flight track is now processed and the flight track needs to be delivered to the users of the FTDS system 1 . The FTDS server 110 may also contain web server 130 software to distribute the flight tracks to users of the FTDS system 1 . In the exemplary embodiment of the FTDS system 1 shown in FIG. 1, the flight track generated by the FTDS system server 120 may be transmitted to a plurality of users (e.g., users 200 - 202 ) via a communications network 50 (e.g., the Internet). The web server 130 software may host a web page containing the necessary data and information to display the tracking information by local users. The users 200 - 202 may operate a web browser such as Microsoft's Internet Explorer, Netscape Navigator, or other third-party web browsing software which may access the web page hosted by web server 130 software. The web browser software operated by the users 200 - 202 will manage the flight track information that is transmitted to the client users 200 - 202 from the web server 130 software of the FTDS server 110 . The data transferred from the FTDS server 110 may be, for example, HTML code or applets.
[0023] Thus, when a user (e.g., users 200 - 202 ) connects to the FTDS server 110 via communications network 50 , the web server 130 software may send an FTDS applet to the user to enable the user to display and control the flight track data sent from the FTDS server 110 to the user. The applet code transferred to the user may be executed by the user's browser to display the tracking information. As the user remains connected to the FTDS server 110 , the web server 130 software will continue to deliver data to update the flight tracks on the user's screen. The update may be performed automatically each time the FTDS server 110 receives updated information from the data feed arrangement 100 . For example, if the PASSUR™ System is used as the data feed arrangement 100 , the updates may occur approximately every 4.6 seconds, i.e., the time that the FTDS server 110 receives updates from the PASSUR™ System plus the processing and data transmission times. The data may be formatted by the FTDS server 110 and delivered to the web browser of the users 200 - 202 in any standard web browser readable format, for example, HTML format, Java, Java Script, etc.
[0024] [0024]FIG. 3 shows an exemplary display screen 300 that may be generated by the FTDS system server 120 and transmitted to the users 200 - 202 via the web server software 130 . The exemplary display screen 300 shows a web page display that is formatted by the Netscape Navigator web browser (e.g., the web browser on users' stations 200 - 202 ). The display screen 300 includes a map portion 302 , a map range field 304 , a flight information box 306 a legend box 308 and a replay field 310 . Each of these areas will be described with reference to the display 300 , except for the replay field 310 which will be described with reference to a later exemplary screen.
[0025] This display shows that the airport being used in this example is Logan International Airport in Boston, Mass. The displayed map 302 shows Logan International centered on the map 302 with a zoom set at ten (10) miles from the center as shown by the map range field 304 at the bottom of the screen 300 . As can be seen from the map range field 304 there may be other preset zoom ranges, e.g., 4 miles, 20 miles, 40 miles, 90 miles. It may also be possible to have a variable zoom and pan features as are known in the art, i.e., the zoom may be adjusted to any level of detail desired by the user and/or the user may recenter the map on another feature rather than the airport itself.
[0026] This example display screen 300 is a near real time display as shown in the flight information box 306 , the display is current as of the date and time of Mar. 30, 2003 at 16:15:54. This display is termed a near real time display because, while it is possible to create a real time display according to the present invention, this embodiment utilizes a ten (10) minute delay for security purposes. Thus, a user would see the display screen 300 at the real time of Mar. 30, 2003 at 16:25:54 (i.e., ten (10) minutes after the time shown in the flight information box 306 ). The other information contained in the flight information box 306 will be described in greater detail below.
[0027] Referring to the map portion 302 , there are five (5) airplane icons 315 - 319 shown on the map 302 . These icons 315 - 319 represent the current location (as of the date/time shown in the flight information box 306 ) of the aircraft that are currently being tracked within the confines of the map 302 area. The display 300 for the present invention may have the capability to display a plurality of aircraft tracks (e.g., up to 40 separate tracks in the target area) overlaid on the background map 302 . There may be more aircraft currently being tracked by the exemplary FTDS system 1 , but these aircraft are not located within the zoom area of the map 302 currently being displayed, i.e., these other aircraft are outside the 10 mile zoom area of map 302 .
[0028] Each aircraft icon 315 - 319 is displayed with a “tail” showing its most recent flight path. For example, an aircraft icon 319 is shown on the display 300 having tail 329 . This display may show the entire path of aircraft 501 when it is in the target area. Thus, the aircraft icon and the tail represent the flight track of the target aircraft. The FTDS system server 120 software generates this flight track for aircraft located in the target area using the data in the target flight record for the target aircraft.
[0029] As described above, the FTDS system server 120 receives target data points for the target aircraft from the data feed arrangement 100 . The FTDS system server 120 combines these data points into a target flight record. Therefore, if it was considered that each target data point for a target aircraft included a target identification, the time and the target's position (x-y position), the FTDS system server 120 would then combine each of these target data points into a target flight record that would contain the target's position over time. The FTDS system server 120 may then use this data to generate the aircraft icon and the tail in the proper location on the map 302 .
[0030] As described above, the target data points are received from data feed arrangement at some time interval (e.g., every 4.6 seconds for the PASSUR™ System). An aircraft may be traveling at hundreds of miles per hour, thus the location of the aircraft may change significantly within this time interval. The FTDS system server 120 may have to interpolate the path of the aircraft during this missing time (i.e., the FTDS system server 120 has the location at time 1 and at some later time 2, but needs to interpolate the locations between these two times). Thus, when the aircraft is flying a straight line or a making a turn, smoothing techniques based on the previous locations are used to create smooth flight tracks. Also, as described above a data feed arrangement such as the PASSUR™ System may input the target data points that have already been smoothed by a smoothing algorithm.
[0031] The legend box 308 of the display 300 shows a legend which may be used to aid users in understanding the display. The legends may be color codes which aid in quickly identifying the nature of the display. The specific color codes are not shown in the black and white drawing of FIG. 3, but exemplary color codes will be described. The first color code may be a code to easily identify the location of the airport (e.g., the Logan International location is shown in gray on the map 302 ). The second color code identifies those flights which departed from Logan International (e.g., all green aircraft icons took off from Logan). The third color code identifies those flights which are to arrive at Logan International (e.g., all blue aircraft icons are scheduled to land at Logan). The fourth color identifies those flights which are in transit (e.g., all black aircraft icons are traveling through the target area, but did not take off and are not scheduled to land at Logan). The fifth color icon is for those aircraft that have been selected by the user (e.g., the red aircraft icon has been currently selected by the user). The purpose and process of selecting an aircraft will be described in greater detail below. Another example of a color code may be a color code for a plane that is to land at a nearby airport.
[0032] These color codes as described for the legend box 308 will aid the user to quickly and easily identify information about a particular flight track. The information used to provide the color coding for the aircraft is provided to the FTDS system server 120 by the data feed arrangement 100 . For example, the target data point for each target aircraft may include the origin and destination of the aircraft. This data may be used by the FTDS system server 120 to properly color code the corresponding icon. Those of skill in the art will understand that the origin and destination information may be transmitted with each target data point for the target aircraft or with less than each target data point for the target aircraft. Once the origin and destination are associated with a particular flight track in the target flight record by the FTDS system server 120 this information may not be needed for each target data point because the origin and destination will not change over time as parameters such as the aircraft's location.
[0033] [0033]FIG. 4 shows a second exemplary display screen 350 that may be generated by the FTDS system server 120 and transmitted to the users 200 - 202 via the web server software 130 . The display screen 350 includes the same general areas as the display screen 300 , i.e., the map portion 302 , the map range field 304 , the flight information box 306 , the legend box 308 and the replay field 310 . As can be seen from the flight information box 306 , the date/time of this display 350 is Mar. 30, 2003 at 16:16:28 which is thirty-four (34) seconds after the display 300 . In this exemplary display 350 , there are six aircraft icons 315 - 320 . The icons 315 - 319 represent the same flight tracks as shown on display 300 . A comparison of the displays 300 and 350 will show that the aircraft icons 315 - 319 have moved their relative locations on the map 302 in the thirty-four seconds which has elapsed between the displays (e.g., aircraft icon 318 has almost moved out of the map range on the display 350 ). It should be understood that the thirty four seconds between the displays 300 and 350 is only exemplary and that an actual user logged into the exemplary FTDS system 1 may see multiple screen updates in this thirty four second period (e.g., every 4.6 seconds when the data feed arrangement 100 is the PASSUR™ System).
[0034] The aircraft icon 320 is a new flight track that has appeared on display 350 that was not on display 300 . The color coding of the aircraft icon 320 may indicate that the target aircraft has departed from Logan International. This flight track provides an example of a new target flight record being created by the FTDS system server 120 . For example, at some time between the time of the display 300 and the display 350 (e.g., the thirty-four second interval), the target aircraft represented by the icon 320 departed from Logan International. The data feed arrangement 100 sent a target data point for that aircraft to the FTDS system server 120 which attempted to place the data from the target data point into a target flight record. However, the FTDS system server 120 determined that this target data point was not associated with any currently tracked aircraft and therefore this was a new aircraft for which a new flight track is to be created. Therefore, the FTDS system server 120 created a new target flight record and saved the target data points for this aircraft in the new target flight record. The FTDS system server 120 then used the data in the new target flight record to create the flight track 320 displayed on the display 350 .
[0035] Referring to the flight information box 306 of the display 350 , information in addition to the current date and time is shown in the flight information box 306 . Specifically, the Aircraft Type (“B738”), the altitude (1100 ft) and the track ID (142). This additional information is specific for an individual flight track as displayed on the map 302 . As shown at the top of the flight information box 306 , the display 350 allows for a user to “Click on any airplane at left for details.” Thus, a user displaying the display 350 may, for example, select a particular flight track by placing the mouse icon on the aircraft icon and clicking. The user may receive a positive feedback from the display in the form of the aircraft icon changing from its current color coding to a color coding indicating that the flight track was selected. The color coding indicating that an aircraft was selected may be displayed in legend box 308 . Once the individual flight track has been selected, additional information for that flight may be displayed in the flight information box 306 .
[0036] To give a specific example of a flight track being selected, it may be considered that on the display 350 , the user placed the mouse icon over the aircraft icon 316 and clicked. As a result, the aircraft icon may have changed color from a blue icon indicating the aircraft is scheduled to land at Logan International to a red icon indicating that the user has selected this flight track to obtain additional information about the aircraft's flight path. Simultaneously with this selection, the additional information for this flight path 316 appeared in the flight information box 306 . This additional information included the type of aircraft (B738), the current altitude (1100 ft) and the track ID (142) for this aircraft. This information may also be included in the target data points provided by the data feed arrangement 100 to the FTDS system server 120 for each aircraft being tracked. Thus, the user has obtained additional information about the flight track of interest by simply clicking on the aircraft icon.
[0037] As shown in flight information box 306 , there may be additional information that can be displayed for the flight track. However, this information may not be displayed at this time for a variety of reasons. For example, because of security concerns the airport/airline may not desire to display the flight identification information or the origin/destination information on the near real time display. Another example may be that some information is not yet available. For example, as described above, the data feed arrangement 100 may actually be a series of independent data feed arrangements which contribute different data to the FTDS system server 120 . These independent data feed arrangements may send this data at different times and different data refresh rates. Thus, the FTDS system server 120 needs to correlate this varying data to the correct target flight record and compare the data from the varying data feed arrangements to insure the accuracy of the information. In such cases, not all the information may be correlated and verified to be displayed on the near real time display.
[0038] [0038]FIG. 5 shows an exemplary display screen 400 that may be generated by the FTDS system server 120 in response to a user's replay request. The display screen 400 has the same general areas 302 - 310 as the previously described displays 300 and 350 . However, the exemplary display 400 is not a near real time display as the displays 300 and 350 , but is a replay of past activity. The replay field 310 of the display 400 allows a user to select a past date and time to begin playback of the flight tracks from that time. In this example, the user has selected via the pull-down menus in the replay field to begin playback on Mar. 12, 2003 at 16:00. The user may then click on the start replay button in the replay field.
[0039] In response to this request from the user, the FTDS system server 120 will retrieve the saved target flight records which include this date/time information and begin the replay of the flight tracks starting with the time entered by the user. As can be seen from the flight information box 306 , the display 400 is from Mar. 12, 2000 at 16:01:32 or 1 minute 32 seconds after the replay started as entered by the user. The FTDS system server 120 retrieved the applicable target flight records and used the data to generate the flight tracks 401 - 403 as shown on the map 302 . The method of generating the flight tracks is the same as that with the real time data except that the FTDS system server 120 is not using the information currently being received from the data feed arrangement 100 . Rather, the data is from archived target flight records which correspond to the time entered by the user.
[0040] The only limitation on the replay feature may be the amount of data which can be stored in the FTDS server 110 . As long as the FTDS system server 120 can access the appropriate target flight records, the FTDS system server 120 can generate the flight tracks using the archived data. In addition, the FTDS system server 120 may generate the replay flight tracks in a fast forward manner. For example, the flight tracks may be displayed in 5 times (5×) speed or any other speed selected by the user. Since the data is archived data, the FTDS system server 120 does not need to wait for the data feed arrangement to send new target data points for the flight tracks, it merely needs to generate the flight tracks from the archived target flight records.
[0041] [0041]FIG. 6 shows a second exemplary display screen 450 that may be generated by the FTDS system server 120 in response to a user's replay request. The display 450 once again contains the same areas 302 - 310 as described for the previous displays. The display 450 is a continuation of the replay which was described with reference to display 400 in FIG. 5. The flight information box 306 shows that the flight tracks currently being displayed are from Mar. 12, 2003 at 16:02:18 or forty-six (46) seconds after the display 400 . As can be seen from the flight tracks 401 - 403 , the aircraft icons have been displaced from the locations shown on display 400 .
[0042] In this exemplary display 450 , the user has selected the flight track 402 to obtain additional information by placing the mouse icon over the aircraft icon 402 and clicking. In response, the aircraft icon 402 has changed color indicating that it has been selected for a request of additional information. Simultaneously, the information concerning the flight is displayed in flight information box 306 . In contrast to display 350 , all the information for the current flight is displayed. Since the current display is a replay all the data has been correlated and verified and there are no safety concerns about providing the user with flight information at a time which may be hours, days, weeks or months after the flight has passed through the airspace. Thus, the user now has all the available information about this particular flight, including the flight ID (UCA8721) the origin (ALB) and the destination (BOS). Those of skill in the art will understand that the display 450 is only exemplary and that depending on the amount and type of data provided by the data feed arrangement 100 , the flight information box 306 may provide more or less information than shown in the display 450 . Examples of enhanced data about the flight may include the type of engines on the plane, the manufacture date of the plane, etc. The user may also revert back to the near real time display by clicking the current button provided in the replay field 310 .
[0043] It should be understood that a user may use the current displays and the replays displays to gain a complete understanding about the flight track of a particular aircraft. For example, the user may hear or see an airplane fly over his house at a particular time. The user may then use the near real time display to determine certain information about the flight as shown on display 350 of FIG. 4. The user may then go back and use the replay function at a later time to display the same flight track to obtain the complete information for the flight as shown in display 450 of FIG. 6. Since the user may enter the time for the replay and since the initial information provides a time/date and a track ID, the user may easily verify that he is obtaining information on the same flight.
[0044] [0044]FIG. 7 shows an exemplary display screen 500 that may be generated by the FTDS system server 120 which has a wider zoom display. Once again, the display 500 has the same general areas 302 - 310 as shown and described for previous displays. The display 500 is a continuation of the replay started in the examples of displays 400 and 450 . However, in this exemplary display 500 , the zoom range has been expanded to 40 miles, i.e., Logan International airport is shown in the center of the map 302 , but the map extends for 40 miles around the airport. This 40 mile zoom range is indicated by the map range field 304 .
[0045] The number of flight tracks to be displayed may depend on the zoom level and the appearance on the screen. Thus, there are more flight tracks on the display 500 having a zoom range of 40 miles as opposed to the previously described displays 300 , 350 , 400 , 450 having zoom ranges of 10 miles. In some cases, the screen may appear too cluttered in high traffic local areas, e.g., New York, Los Angeles and other major metropolitan areas. In this case, filters may be used to reduce screen clutter. For example, a filter may be used to select only the flights associated with a particular airline or the “n” closest flights to these selected flights. Those of skill in the art will understand that there may be any number of filters that may be used to reduce the number of tracks shown an any particular screen. By selecting these filters, a user (e.g., users 200 - 202 ) may obtain the desired picture for presentation.
[0046] The present invention may also allow the developer to control the appearance of the display. This feature is for access of the developer to the information contained on the FTDS server 110 so the developer may change the features and functionality of the FTDS system 1 . For example, the control may allow the developer to control the number of tracks to be displayed, the area of the display coverage and the selection of the appropriate background map. This feature may also allow the user or developers to apply certain overlays on the map, e.g., the street address or location of the user, a weather overlay from the National Weather Service, etc. Another feature which may be implemented in the FTDS system 1 is a find flight function. In this case the user may enter information about a particular flight and the FTDS system 1 would find the flight and display the flight track for that flight.
[0047] The FTDS system 1 enables the users 200 - 202 to become informed about the airspace surrounding their neighborhood and noise events resulting from aircraft. This information may lead to a reduction in call volume to the noise office of the local airport and a reduction in the costs associated with that office. Similarly, the noise office may be able to respond in a faster manner to complaints and other requests because the user will be informed and have the complete information about a particular flight.
[0048] As described above, the flight tracks may also be for other aircraft beside planes such as helicopters. The determination of whether a particular target aircraft is a helicopter as opposed to a plane may be determined by the performance of the aircraft. For example, the altitude, speed, flight pattern and beacon code may be used to distinguish a helicopter.
[0049] In the preceding specification, the present invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made thereunto without departing from the broadest spirit and scope of the present invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense. | A system, comprising a data receiving arrangement to receive target data points from a data feed arrangement, each target data point including data corresponding to a location of a target aircraft and additional information on the target aircraft, a data analyzing arrangement to analyze the target data points and store each target data point in a target flight record, the target flight record corresponding to the target aircraft a data generation arrangement to generate a flight track for the target aircraft using the data stored in the target flight record and a data distribution arrangement to organize the flight track and the additional information into a displayable file and distribute the file to users of the system, wherein the displayable file is displayed on a single graphical user interface including the flight track and the additional information. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S. Provisional Patent Application No. 61/042,866, filed on Apr. 7, 2008, which is incorporated herein by reference.
BACKGROUND
[0002] Since the inception of primitive information storage and communication through devices such as carvings in stone and wood, data has played an increasingly important role in society. In more modern times, inventions such as written language, the printing press, and photography have enabled communication between people on a global scale. Countless reams of history are stored on both printed and photographic paper. Since many of these paper documents are degrading rapidly, the risk of losing many primary source records documenting our modern history is considerable.
[0003] Damage to antique documents falls into the categories of mechanical and chemical. Mechanical damage includes defects such as cracks and scratches. Cracks generally do not have a common direction, whereas scratches usually have a specific orientation. Chemical damage occurs in the forms of semi-transparent blotches, gaps, and foxing. Semi-transparent blotches are frequently caused by water or humidity and cause each pixel to contain both noise and information about the original image. Gaps are caused by reactions between chemical agents and the film's gelatin, leaving a single gray level in a section of the image. Foxing creates red-brown areas due to microorganisms. Finally, the image may also be damaged when various materials are deposited on the picture or document's surface.
[0004] Many preservation efforts are been underway to protect antique images and documents. The first step has been to protect the original paper documents through means such as environmentally-controlled rooms. Furthermore, numerous documents are restored using chemical techniques. Generally, chemical methods start with a cleaning of the original, proceed to a physical restoration of the media, and conclude with some repainting of the restored media. Though this method improves image quality, it is clearly labor-intensive and the cost of restoring a single image is sizable.
[0005] As a solution to the cost problems associated with physical photograph restoration, digital restoration methods have been proposed. With the introduction of high-quality, low-cost color scanners and printers, restoring a photograph becomes a matter of scanning in the original, making modifications in the digital domain, and then either storing the image digitally or reprinting it. Though such an approach appears simple, modifying the scanned image in the digital domain is actually a complicated procedure. Currently, the most commonly used approach is to employ highly-trained operators and commercial software such as Adobe Photoshop or the GNU Image Manipulation Program to restore images. Though restoration through such software is less expensive than chemical restoration, one who is skilled in the art will readily appreciate that software restoration is a time-consuming process. Thus, beyond the cost of scanning the original, damaged documents, current digital photograph restoration still involves great operator expense.
[0006] Clearly a completely automated digital photograph restoration technique would reduce operator cost. Many automated and semi-automated approaches have been proposed and digital photograph restoration has been proven to be useful for the following reasons: restoration is reversible and the original document is not damaged; partial or complete automation reduces the amount of time for restoration, thus allowing for the processing of large quantities of images; and finally digital restoration is economical and affordable for any photographer or museum.
[0007] While a number of patents describing image restoration techniques have been issued, none provide an automated defect restoration system. U.S. Pat. No. 5,623,558 describes a system in which only completely undefined pixel locations are restored and where parts of the algorithm are not automated. U.S. Pat. No. 5,796,874 describes the restoration of faded images and requires user interaction. U.S. Pat. No. 6,487,321 describes a method for modifying defects in a digital image that are generally caused by analog-to-digital conversion and are not due to defects (e.g., blotches, cracks, and so on) in the original source image. U.S. Pat. No. 6,636,645 B1 describes a system in which noise and blocking artifacts are restored through the use of a user-specified noise table. U.S. Pat. No. 5,771,318 describes an edge-preserving smoothing filter, but does not restore old documents. U.S. Pat. No. 5,414,782 focuses on using partial restorations to retrieve details from images that are typically lost in other restoration techniques. Using these partial restorations, one can then tune parameters for other algorithms. However, this involves significant user interaction. U.S. Pat. No. 6,792,162 automatically enhances a digital negative, but cannot restore old documents. U.S. Pat. No. 6,879,735 presents a method for sharpening a blurred image, but again cannot be used for generalized old document restoration. U.S. patent application Ser. No. 10,887,998 removes semi-transparent artifacts from digital images, but only does so only when the artifacts are caused by contaminants in the optical path to the camera and is not capable of restoring old documents. U.S. patent application Ser. No. 11,236,805 describes as system of identifying and removing semi-transparent blotches; however, the system requires a clean reference image. The present invention does not require a clean reference image for the restoration of images damaged by semi-transparent blotches. U.S. patent application Ser. No. 12/032,670 describes an automated defect restoration system; however, the system only works for correcting dust marks that are generally due to a dusty camera lens and the system cannot restore semi-transparent blotches.
[0008] In addition to patents issued in the field of image processing, there is significant existing research on the subject of blotch removal. Existing work broadly falls into the categories of general photograph enhancement techniques, blotch removal from multi-frame film sequences, text enhancement, and blotch removal from single frames, as in the application of document restoration.
[0009] In general, several approaches to digital image restoration have been developed. One known approach referred to as histogram equalization, generates a restoration transfer function based upon the cumulative distribution function of the grey levels in an image. In order to overcome contrast losses associated with histogram equalization over the entire image, there is introduced a locally adaptive variant of histogram equalization. In another known approach, a more efficient algorithm can be used. Though this may address some of the performance issues with the approach of histogram equalization, it also demonstrates that histogram equalization may be useful for enhancing the overall contrast of an image and not for local defects such as semi-transparent blotches.
[0010] Adaptive nonlinear filters are also commonly used for image enhancement, which, as compared to prior works, improves contrast enhancement while performing noise reduction and edge enhancement. However, in the application of semi-transparent blotches, the parameters required for each blotch are different and unknown.
[0011] Another commonly used digital image enhancement technique is anisotropic diffusion. In another approach, a mathematical analysis of an anisotropic diffusion filter for ultrasound images is presented in which ultrasound noise is highly predictable and occurs in well-defined curves. This approach presents an adaptable ultrasound filter that significantly reduces noise in ultrasound images. Since the characteristics of the noise in semi-transparent blotches vary widely, these approaches are not suitable.
[0012] Adaptive contrast enhancement is another traditional image enhancement technique for the detection of blood vessels in retinal images. Adaptive contrast enhancement is used to only increase contrast in the area of blood vessels without creating background contrast objects. Though useful for the application of blood vessel detection, when applied to semi-transparent blotches, adaptive contrast enhancement frequently creates bright contrast objects that further corrupt the image.
[0013] Another approach to document and image defect removal is to replace damaged data with new pixels. Replacement approaches assume that the damaged areas of the image are completely lost and irrecoverable; therefore the only solution is to generate new data.
[0014] An example of a replacement approach includes using texture synthesis methods to generate new patterns to replace missing sections of data in an image. This does not require a regular prototype pattern, such as the mortar lines in a wall of bricks, and works well on natural images. However, this method is not effective for semi-transparent blotches.
[0015] Inpainting is another common replacement technique that may work well for repairing cracks in images. Further development of inpainting has been used to effectively remove limitations on the topology of the region to be inpainted. Yet another method of inpainting utilizes Gestaltist's Principle of Good Continuation to interpolate image data based on data from local gray levels and gradients. However, inpainting methods do not restore the original image data, which is a desirable feature for semi-transparent blotch removal.
[0016] In another approach, spatial and frequency domain information are utilized for noise reduction in images. Using a prototype image, there is replacement of the noise in an image with new pixels. Run iteratively, the algorithm can repair contiguous sections of the image effectively. However, this approach still replaces information, making it inappropriate for semi-transparent blotches.
[0017] In addition to the restoration of individual images, film restoration has seen considerable attention in research. Semi-transparent blotches are one type of defect in film and typically only affect individual frames. Most film restoration algorithms rely on information from several frames, thus making them unsuitable for the applications of document and photograph restoration.
[0018] For example, one approach detects blotches by assigning a probability to each pixel of being in a blotch. This probability is generated using both spatial and temporal analysis. Once the probabilities are assigned, they are used as a restoration parameter and anisotropic smoothing is performed to conclude the process. This approach is more robust to noise and errors than prior approaches; however, it does require training data, which is not available for semi-transparent blotches due to the inconsistent nature of each blotch.
[0019] Additionally, old film frequently has frame-alignment errors. Using a morphological detector, it can be assumed that the blotches are a local minima or maxima and removes the blotches using a motion estimator and multilevel median filtering. The algorithm performs blotch correction and contrast enhancement simultaneously. However, this requires information from multiple frames, which is not available for still photographs or documents.
[0020] In yet another approach, a system combines spatial and temporal information for blotch detection using Dempster-Shafer fusion. Using morphological functions to compare the detected shape with a prototype of a blotch, the system is able to effectively detect blotches in old film sequences, but not single-frame images.
[0021] In a further approach, rank ordered differences are employed to compare motion compensated frames and detect blotches and scratches in old film sequences. This approach provides better performance and lower computational load as compared to prior approaches. Similarly, another know system also detects blotches and scratches but utilizes heuristic and model-based methods. However, both methods require information from multiple frames.
[0022] In addition to a variety of image restoration techniques, many methods specific to text and handwriting have been developed: One such method introduces the Integral Ratio, which is a two-stage thresholding process designed to separate handwriting from various backgrounds. Another approach introduces a locally-adaptive, parameter-free binarization algorithm that extends upon Niblack's binarization using morphological and gradient-based error correction steps. However, text enhancement methods do not restore the background, thus making them unsuitable for semi-transparent blotch restoration. There has also been significant work in the area of text segmentation, which is a subset of the text binarization problem. One commercial application would be faxed documents, thus providing an incentive to study this problem. Though text binarization approaches effectively restore text, they do not consider the background. Background restoration is required for the removal of semi-transparent blotches, and thus text binarization approaches are not sufficient.
[0023] Of the known approaches that are specifically designed for the semi-transparent blotch removal, all have limitations. For example, some approaches leave visible borders around the perimeter of the blotch location and blotch detection involves considerable user interaction that improves upon detection but still requires user interaction for restoration. Another approach improves upon detection but is not user independent. A further approach improves upon other techniques, but assumes that the blotch is in a text document. Another approach presents a wavelet-based technique.
SUMMARY
[0024] The present invention provides methods and apparatus for digital restoration of images having defects. Applications of the present invention include the restoration of images damaged by semi-transparent blotches, cracks, fading, and the like. Exemplary embodiments of the present invention are applicable to a wide variety of areas, including medical imaging, object detection and control, image forensics and other.
[0025] In one aspect of the invention, a method for repairing a defect in a digital image to provide a restored image comprises determining, using a computer having a processor, a plurality of pixel locations to form a neighborhood relating to the defect and whether the neighborhood has a defined edge, where it is determined that the defined edge is not present, (a) processing the neighborhood to bring the neighborhood to a more uniform darkness, (b) processing the uniform darkness neighborhood to match surroundings in the digital image, (c) copying an edge of a neighborhood in the digital image into the processed neighborhood, (d) processing pixels of the edge to repair the copied edge pixels, and (e) outputting the restored image for display to a user, where it is determined that the defined edge is present, (f) processing the neighborhood to locally enhance the neighborhood and match surroundings in the digital image, (g) processing the neighborhood edge such that the edge also matches surroundings in the defect and the digital image, (h) processing the neighborhood to invert pixel values and perform steps (f) and (g) again, (i) processing the neighborhood to increase its contrast and performing steps (f)-(h) again, (j) processing the neighborhood to bring the neighborhood to a more uniform darkness, (k) processing the uniform darkness neighborhood to match surroundings in the digital image, and (l) outputting the restored image for display to a user.
[0026] The method can further including one or more of the following features: processing the neighborhood to bring the neighborhood to a uniform darkness includes using a localized value derived from local pixel values and statistical values in the neighborhood, processing the uniform darkness neighborhood to match surroundings in the digital image includes a variance parameter, a luminosity parameter, and a tuning parameter, processing the neighborhood to bring the neighborhood to a uniform darkness includes computing: R(ω x,y )=L(f,g,h,λ) where R(ω) represents repaired neighborhood pixels, L is a generic function, processing the uniform darkness neighborhood to match surroundings in the digital image includes computing: R(ω)=k(I(ω)), where k is a generic function, processing the neighborhood edge also matches surroundings in the defect and the digital image includes computing:
[0000]
R
(
ω
x
,
y
)
=
(
p
(
·
)
q
(
·
)
)
[0000] where K(ω) represents the edge pixels to be restored, and x is a generic function, processing the neighborhood's edge such that the edge also matches its surroundings in both the defect and the digital image includes computing: R(ω)=K(ω x,y )·x(•) where K(ω) represents the edge pixels to be restored, and x is a generic function, the set of locations is identified using a separate defect location map such as a mask or any other detection method, restoration occurs using local and/or global image processing, the steps of image restoration are performed using a computer, the process is applied to an image having a plurality of pixel values for any given pixel location including a color value, color planes are separated prior to processing and recombined after processing, the defect includes a semi-transparent blotch, the defect includes text degradation, the defect includes a crack.
[0027] In another aspect of the invention, a system comprises a processing and a memory to provide an edge analysis module to detect an edge of a defect in a neighborhood in a digital image, a uniform intensity module to bring the neighborhood to a more uniform darkness, a uniform intensity module to process the uniform darkness neighborhood to match surroundings in the digital image, an edge pixel module to copy an edge of a neighborhood in the digital image into the processed neighborhood, an edge pixel restoration module to process pixels of the edge to repair the copied edge pixels, and an output module to output the restored image for display to a user.
[0028] In a further aspect of the invention an article comprises a storage medium containing stored instructions that when executed enable a machine to perform: determining, using a computer having a processor, a plurality of pixel locations to form a neighborhood relating to the defect and whether the neighborhood has a defined edge, where it is determined that the defined edge is not present, (a) processing the neighborhood to bring the neighborhood to a more uniform darkness, (b) processing the uniform darkness neighborhood to match surroundings in the digital image, (c) copying an edge of a neighborhood in the digital image into the processed neighborhood, (d) processing pixels of the edge to repair the copied edge pixels, and (e) outputting the restored image for display to a user, where it is determined that the defined edge is present, (f) processing the neighborhood to locally enhance the neighborhood and match surroundings in the digital image, (g) processing the neighborhood edge such that the edge also matches surroundings in the defect and the digital image, (h) processing the neighborhood to invert pixel values and perform steps (f) and (g) again, (i) processing the neighborhood to increase its contrast and performing steps (f)-(h) again, (j) processing the neighborhood to bring the neighborhood to a more uniform darkness, (k) processing the uniform darkness neighborhood to match surroundings in the digital image, and (l) outputting the restored image for display to a user.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The foregoing features of this invention, as well as the invention itself, may be more fully understood from the following description of the drawings in which:
[0030] FIG. 1 is a block diagram of an exemplary system for digitally restoring images in accordance with exemplary embodiments of the invention;
[0031] FIG. 2 is a flow diagram showing an exemplary sequence of steps for implementing image restoration in accordance with exemplary embodiments of the invention;
[0032] FIG. 3A shows an original image;
[0033] FIG. 3B shows the original image of FIG. 3A processed in accordance with exemplary embodiments of the invention;
[0034] FIG. 4A shows an original image;
[0035] FIGS. 4B and 4C show the image of FIG. 4A processed using prior art techniques;
[0036] FIG. 4D shows the original image of FIG. 4A processed in accordance with exemplary embodiments of the invention;
[0037] FIG. 5A shows an original image;
[0038] FIG. 5B shows the image of FIG. 5A processed using a prior art technique;
[0039] FIG. 5C shows the original image of FIG. 5A processed in accordance with exemplary embodiments of the invention;
[0040] FIG. 6A shows an original image;
[0041] FIG. 6B shows the original image of FIG. 6A processed in accordance with exemplary embodiments of the invention;
[0042] FIG. 7A shows an original image;
[0043] FIG. 7B shows the original image of FIG. 7A processed in accordance with exemplary embodiments of the invention;
[0044] FIG. 8A shows an original image;
[0045] FIG. 8B show the original image of FIG. 8A processed using a prior art technique.
[0046] FIG. 8C shows the original image of FIG. 8A processed in accordance with exemplary embodiments of the invention;
[0047] FIG. 9A shows an original image;
[0048] FIG. 9B shows the original image of FIG. 9A processed in accordance with exemplary embodiments of the invention;
[0049] FIG. 10A shows an original image;
[0050] FIG. 10B shows the original image of FIG. 10A processed in accordance with exemplary embodiments of the invention;
[0051] FIG. 11A shows an original image;
[0052] FIG. 11B show the original image of FIG. 8A processed using a prior art technique.
[0053] FIG. 11C shows the original image of FIG. 8A processed in accordance with exemplary embodiments of the invention;
[0054] FIG. 12 is a schematic representation of an exemplary system that can execute instructions to perform image restoration in accordance with exemplary embodiments of the invention.
DETAILED DESCRIPTION
[0055] FIG. 1 shows an exemplary system 100 for digitally restoring images in accordance with exemplary embodiments of the invention. An image 10 is input to the system for restoration or enhancement. An edge analysis module 102 examines the edge around a selected region. In an exemplary system, the edge analysis module 102 determines whether edge pixels are darker than blotch pixels. If the edge pixels are not darker, a uniform intensity module 104 processes the image including changing the statistics of a selected region in the image. In an exemplary system, the uniform intensity module 104 modifies the blotch and makes its member pixels close to a statistically-selected gray level. An intensity correction module 106 then corrects the blotch intensity.
[0056] An edge pixel module 110 copies edge pixels for the blotch from the original image and an edge pixel restoration module 112 restores the edge pixels. An inversion module 108 replaces image values with their compliments and a contrast module 114 increases the contrast of the image. An output module 116 outputs the processed image 20 for display to a user, storage, etc. The processing performed by the modules is described below in detail.
[0057] It is understood that the term blotch should be construed broadly to include semi-transparent regions in general having some type of discoloration typically, but not exclusively, formed during aging in less than ideal storage conditions. While exemplary embodiments of the invention refer to blotches as semi-transparent regions in images, such as water stains, it is understood that embodiments of the invention are applicable to images and blotches of any practical size, shape and intensity.
[0058] Original images are digitized and analyzed to identify defects. One possible method of identifying defects incorporates image segmentation, thresholding, and constraint selection; however, any suitable method of identifying image objects or defects may be utilized in the present invention. Once the defects are detected, global and/or neighborhood operations are used to restore the image. The inventive processing can be used for detection applications in general and used for applications in many fields that will be readily apparent to one of ordinary skill in the art upon reviewing the present disclosure. These fields include but are not limited to medical imaging, control systems, image forensics, and photograph restoration or enhancement.
[0059] Once objects in the image are detected, in the case of image defects, the image can be restored to a more desirable form, irrespective of whether or not an original clean image is not available. Since an individual image may be considered a single frame in a video sequence, exemplary embodiments of the present invention also enable the restoration of defects in video sequences. Automated embodiments of the invention enable video restoration practical. Exemplary embodiments of the invention are applicable to functions in general in which it is desirable to make a decision based upon information within an image.
[0060] In one embodiment, there is automatic identification of a set of locations in a digital image, including digital images that are converted from analog sources through the use of a scanner, camera, or other analog-to-digital converter. Any technique, possibly but not necessarily an automated technique, may be used to identify locations within the image. One exemplary method to identify defects in an image involves the following steps: using any suitable image segmentation technique; thresholding the image at multiple values; and selecting the correct threshold using any sequence of processing steps. Once the objects are selected, their locations are stored in memory for use with a variety of applications. When used for image restoration, processing may use local and/or global image processing to aid in determining defect locations. Furthermore, processing of the image may be iterated to restore multiple overlapping defects or to restore edges around defects. When used for general applications, the stored objects in memory are used in conjunction with some other constraint to make decisions that are pertinent to the application.
[0061] It is readily understood that detecting defects, such as semi-transparent blotches, is a non-trivial problem due to vague definition. That is, blotches can be of any shape, size, and color and can be caused by a variety of sources, each of which causes different edge effects at the border of the blotch.
[0062] In an exemplary embodiment, a blotch/neighborhood is identified in a manner well known in the art, and the blotch is removed from the image also in a manner well known in the art.
[0063] The blotch is then processed. In an exemplary embodiment, a Localized Logarithmic Restoration Algorithm (LLRA) uses information contained within the blotch for image restoration through a combination of adaptive and global processing as described below in detail. After repairing the inside of the blotch, the edges of the blotch are adaptively repaired as described below in detail.
[0064] Semi-transparent blotches can be caused by a variety of sources and therefore have a variety of edge effects. Blotches created by water spreading through a page have a well-defined, dark edge, while other types of blotches do not. Since blotches with darker edges and blotches without well-defined edges benefit from different processing steps, statistical methods are used to determine whether or not the blotch has a darker edge. One of ordinary skill in the art may readily appreciate that edges may be detected through standard edge detectors, such as Sobel or Canny, using morphological techniques, or using other edge detection techniques.
[0065] FIG. 2 shows an exemplary sequence of steps for processing a blotch. In step 200 , a digital image to be processed for restoration is received. In step 202 , one or more blotches are detected in a manner well known in the art. In step 204 it is determined whether the blotch has an edge darker than a selected threshold.
[0066] If it is determined that there is no darker edge to the blotch then processing on the blotch in step 206 is performed to bring the blotch to a more uniform darkness in accordance with Equations (1) and (2):
[0000] R (ω x,y )= L ( f,g,h,λ ) (1)
[0000] λ(•)=Z(i(.),j(.)) (2)
[0067] We have demonstrated the functionality of the present invention using Equations (3) through (7), defined below.
[0000]
f
(
·
)
=
Median
(
I
(
ω
)
)
(
3
)
g
(
·
)
=
I
(
ω
x
,
y
)
(
4
)
h
(
·
)
=
2
·
Median
(
I
(
ω
)
)
(
5
)
i
(
·
)
=
Median
(
I
(
ω
)
)
-
I
(
ω
x
,
y
)
(
6
)
j
(
·
)
=
Median
(
I
(
ω
)
)
(
7
)
L
(
f
,
g
,
h
,
λ
)
=
f
(
·
)
·
(
g
(
·
)
h
(
·
)
)
λ
(
·
)
(
8
)
Z
(
i
(
.
)
,
j
(
.
)
)
=
i
(
·
)
j
(
·
)
(
9
)
[0000] where I(ω) represents the pixels within the blotch and R(ω) represents the repaired blotch pixels at the end of this step. A subscript of x, y indicates that the value is computed at each pixel x, y. Thus, I(ω x,y ) means that the value is computed at each pixel x,y within the blotch.
[0068] Additionally, we define λ, f, g, h, i, j, L, and Z as generic functions, where a generic function may be a local function or a function of a neighborhood in the image or a function of the entire image. Any combination of the above functions, or any other mathematical function, is also acceptable, irrespective of where the function derives its data from. A subset of example functions include: average; median; weighted median or average; alpha-trimmed average; arithmetic average, weighted geometric average; mean average, mode average, local transform (e.g. Fourier, cosine, wavelet and others); DC coefficients, and others. Any other function described as a generic function in this document shall be understood to meet the above criteria.
[0069] After the blotch is brought to a uniform set of gray levels using Equations (1) and (2) above, in step 208 the blotch is corrected to match the surrounding as set forth in Equations (10):
[0000] R (ω)= k ( I (ω)) (10)
[0070] where k is also a generic function.
[0071] In an exemplary embodiment of the invention, functionality is demonstrated using Equations (11) through (17), defined below.
[0000]
k
(
·
)
=
I
(
ω
)
α
·
β
·
γ
(
11
)
α
=
l
(
·
)
m
(
·
)
(
12
)
l
(
·
)
=
log
(
var
[
R
(
ω
)
]
)
(
13
)
m
(
·
)
=
log
(
var
[
I
(
ω
)
]
)
(
14
)
β
=
n
(
·
)
o
(
·
)
(
15
)
n
(
·
)
=
log
(
E
[
R
(
ω
)
]
)
(
16
)
o
(
·
)
=
log
(
E
[
I
(
ω
)
α
]
)
(
17
)
[0072] where k, α, l, m, β, n, and o are generic functions.
[0073] In one embodiment providing a demonstration of the functionality of the present invention, α corrects for the variance within the blotch, β adjusts the overall luminosity of the blotch, and γ is an optional tuning parameter. Alpha and beta, defined in Equations (12) and (15), respectively, are generated automatically by taking statistical information from a border surrounding the blotch that is part of the uncorrupted image. In one embodiment, a small area on the border of the blotch is replaced with the Median[I(ω)]. To address this, that area is copied back in step 210 from the original image for further processing.
[0074] In step 212 , a localized logarithmic restoration algorithm (LLRA) adaptive edge enhancement process repairs the corrupted edges of the blotch as set forth in Equation (18):
[0000]
R
(
ω
x
,
y
)
=
(
p
(
·
)
q
(
·
)
)
(
18
)
[0075] where p and q are generic functions.
[0076] In one embodiment demonstrating the functionality of the present invention using Equations (19) through (28), which are defined below.
[0000]
p
(
·
)
ψ
x
,
y
·
Median
[
I
(
ω
)
]
+
ω
x
,
y
(
19
)
q
(
·
)
=
2
(
20
)
ψ
x
,
y
=
(
r
(
·
)
s
(
·
)
)
γ
x
,
y
(
21
)
r
(
·
)
=
ω
x
,
y
(
22
)
s
(
·
)
=
2
·
Median
[
I
(
ω
)
]
(
23
)
γ
x
,
y
=
t
(
·
)
·
u
(
·
)
(
24
)
t
(
·
)
=
v
(
·
)
-
ω
x
,
y
I
(
ω
)
(
25
)
u
(
·
)
=
2
w
(
·
)
(
26
)
v
(
·
)
=
Median
[
I
(
ω
)
]
(
27
)
w
(
·
)
=
StdDev
[
I
(
ω
)
]
(
28
)
[0077] where p, q, ψ, r, s, γ, t, u, v, and w generic functions.
[0000] Note that Equations (19) to (28) are applied only to edges of the blotch so that I(ω) represents the edge pixels and R(ω) represents the repaired edge pixels. Once Equations (18) has been applied, the restoration is complete so that the restored image can be output in step 224 .
[0078] If it is determined that there is a darker edge around the blotch then processing on blotch in step 214 is performed to bring the blotch to a uniform darkness in accordance with the method used in step 208 and Equation (10).
[0079] In Step 216 , processing is performed to correct the edge around the blotch in accordance with Equation (29):
[0000] R (ω)= K (ω x,y )· x (•) (29)
[0080] where x is a generic function.
[0081] An exemplary embodiment demonstrates the functionality of the present invention using Equations (30) through (33), defined below.
[0000]
x
(
·
)
=
exp
(
γ
·
y
(
·
)
)
(
30
)
y
(
·
)
=
Median
[
Λ
]
(
31
)
Λ
=
z
(
·
)
(
32
)
z
(
·
)
=
log
(
Median
[
I
(
ω
)
]
K
(
ω
)
)
(
33
)
[0082] where x, y, A, and z are generic functions. In equation (33), I(ω) is the same set of pixels as referred to in step 214 . In Equation (30), γ represents an optional tuning parameter.
[0083] In step 218 , the image is processed and steps 214 and 216 are repeated once. In one embodiment, an image inversion is applied in step 218 ; e.g., we replace the image with its negative. Step 220 again involves processing using any suitable method to increase the image contrast. After processing in step 220 is completed, processing performed in steps 214 , 216 , and 218 can be repeated as part of an after processing step 222 . The process is concluded with step 222 , wherein the same process as described for step 206 followed by the process for step 208 is used as an after processing technique to prepare the image for output in step 224 .
[0084] In some cases, processing can be used iteratively when there are multiple defects. As described further below, images can be processed twice using LLRA: One due to a crack in the middle and the second due to the presence of multiple blotches on top of one another, for example. Furthermore, LLRA may be used on color images by processing each color plane individually and recombining the color planes once processing has been completed.
[0085] FIGS. 3-7 show original images and processed images. Original images include old photographs, printed text, and manuscripts. FIG. 3A shows an original image with a typical blotch in a text document. FIG. 3B shows the image after processing in accordance with exemplary embodiments of the invention. As can be seen, the blotch is effectively removed from the original image with minimal edge effects. FIG. 4A shows an original image with a blotch. FIG. 4B shows the image of FIG. 4A processed using F. Stanco, Apollo software, August 2007 having a blurred edge around the location of the blotch. FIG. 4C shows a result having a well-defined edge using A. J. Crawford, et al, “Multi-Scale Semi-Transparent Blotch Removal on Archived Photographs Using Bayesian Matting Techniques and Visibility Laws,” Proc. IEEE International Conference on Image Processing, 2007. FIG. 4D is an image after processing in accordance with exemplary embodiments of the present invention with the edge removed.
[0086] FIG. 5A is an original image with a blotch and a crack through the blotch. FIG. 5B shows the image of FIG. 5A processing using Stanco. FIG. 5C shows the processed image in accordance with exemplary embodiments of the invention including iterative processing, first on the blotch and then on the crack, to repair the damage. The inventive processing improves edge removal and enhances detail preservation within the blotch. It also improves the appearance of the crack.
[0087] FIG. 6A shows an original image of a manuscript having two blotches on top of one another. FIG. 6B shows the image processed in accordance with exemplary embodiments of the invention. In the original image, one can see a lighter blotch that is on the entire left hand side with a darker blotch superimposed on it in the lower left hand corner. The inventive processing was executed once on each blotch to repair the image and generate the image in FIG. 6B .
[0088] FIG. 7A shows an original image of a manuscript where the blotch has significantly degraded the text and FIG. 7B shows the image processed in accordance with exemplary embodiments of the invention. The original images of FIGS. 6A and 7A show documents with blotches caused by mold creating little black dots in the images. In the image of FIG. 7A , in addition to having a blotch caused by mold, the mold has caused significant degradation of the text. While conventional contrast enhancement methods could be used to restore the blotch if masked correctly, in the process, one would also expect the text to be further damaged. By using the inventive processing, the text is not degraded further during restoration. Various text-enhancement algorithms can be applied to the resultant image.
[0089] FIG. 8A shows an original image. FIG. 8B show the original image of FIG. 8A processed using a prior art technique, and FIG. 8C shows the original image of FIG. 8A processed in accordance with exemplary embodiments of the invention. FIG. 9A shows an original image, and FIG. 9B shows the original image of FIG. 9A processed in accordance with exemplary embodiments of the invention. FIG. 10A shows an original image, and FIG. 10B shows the original image of FIG. 10A processed in accordance with exemplary embodiments of the invention. FIG. 11A shows an original image. FIG. 11B show the original image of FIG. 11A processed using a prior art technique, and FIG. 11C shows the original image of FIG. 11A processed in accordance with exemplary embodiments of the invention;
[0090] Exemplary embodiments of the invention provide methods and apparatus for localized logarithmic restoration that provides an adaptive, automatic framework for repairing documents damaged with semi-transparent blotches without blurring the documents or leaving edges around the location of the blotch. Processed images have improved local contrast preservation, expanded saturation reduction capabilities, and improved edge removal, as compared with known restoration processing techniques. The inventive image restoration process can be applied for blotch removal, text enhancement, restoration of cracks, etc., in a variety of documents, including but not limited to texts, manuscripts, and historic images. In addition, the invention image processing is well suited for batch processing of large quantities of documents and images.
[0091] It is understood that exemplary embodiments of the invention described herein can be implemented in a variety of hardware, software, and hardware/software combinations. In one embodiment, the processing for the system of FIG. 1 , for example, can be implemented on a computer. FIG. 12 shows an exemplary computer including a processor 602 , a volatile memory 604 , a non-volatile memory 606 (e.g., hard disk), a graphical user interface (GUI) 608 (e.g., a mouse, a keyboard, a display, for example). The non-volatile memory 606 stores computer instructions 612 , an operating system 616 and data 618 . In one example, the computer instructions 612 are executed by the processor 602 out of volatile memory 604 to perform all or part of the exemplary processing.
[0092] The processing described herein is not limited to use with the hardware and software of FIG. 12 ; they may find applicability in any computing or processing environment and with any type of machine or set of machines that is capable of running a computer program. Processing may be implemented in hardware, software, or a combination of the two. Processing may be implemented in computer programs executed on programmable computers/machines that each includes a processor, a storage medium or other article of manufacture that is readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and one or more output devices. Program code may be applied to data entered using an input device to perform processes and to generate output information.
[0093] The system may be implemented, at least in part, via a computer program product, (e.g., in a machine-readable storage device), for execution by, or to control the operation of, data processing apparatus (e.g., a programmable processor, a computer, or multiple computers)). Each such program may be implemented in a high level procedural or object-oriented programming language to communicate with a computer system. However, the programs may be implemented in assembly or machine language. The language may be a compiled or an interpreted language and it may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program may be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network. A computer program may be stored on a storage medium or device (e.g., CD-ROM, hard disk, or magnetic diskette) that is readable by a general or special purpose programmable computer for configuring and operating the computer when the storage medium or device is read by the computer to perform processing. Processing may also be implemented as a machine-readable storage medium, configured with a computer program, where upon execution, instructions in the computer program cause the computer to operate.
[0094] The processing associated with implementing the system may be performed by one or more programmable processors executing one or more computer programs to perform the functions of the system. All or part of the system may be implemented as, special purpose logic circuitry (e.g., an FPGA (field programmable gate array) and/or an ASIC (application-specific integrated circuit)). Elements of different embodiments described herein may be combined to form other embodiments not specifically set forth above. Other embodiments not specifically described herein are also within the scope of the following claims.
[0095] Having described exemplary embodiments of the invention, it will now become apparent to one of ordinary skill in the art that other embodiments incorporating their concepts may also be used. The embodiments contained herein should not be limited to disclosed embodiments but rather should be limited only by the spirit and scope of the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety. | Methods and apparatus for restoration of a digital image. In one embodiment, a method for repairing a defect in a digital image to provide a restored image comprises determining a plurality of pixel locations to form a neighborhood relating to the defect and whether or not the neighborhood has a well-defined, dark border along its edge. Should the neighborhood not have dark border, one embodiment of the method entails processing the neighborhood to bring the neighborhood approximately to uniform darkness, processing the neighborhood to match surroundings in the digital image, copying an edge of a neighborhood in the digital image into the processed neighborhood, processing pixels of the edge to repair the copied edge pixels, and outputting the restored image for display to a user. Should the neighborhood have a dark, well-defined border, one embodiment of the method entails processing the neighborhood as to locally enhance the neighborhood and match its surroundings in the digital image; processing the neighborhood's edge such that the edge also matches its surroundings in both the defect and the digital image; processing the neighborhood to invert its pixel values and then perform the last two steps once again; processing the neighborhood to increase its contrast and then perform the last three steps once again; processing the neighborhood to bring the neighborhood to a more uniform darkness; processing the uniform darkness neighborhood to match surroundings in the digital image; and outputting the restored image for display to a user. | 6 |
This is a division of application Ser. No. 704,238, filed Feb. 22, 1985 now U.S. Pat. No. 4,600,790.
The present invention relates to organosilicon compounds containing biuret groups, particularly to organosilicon compounds containing SiC-bonded biuret groups and more particularly to a method for preparing organosilicon compounds containing SiC-bonded biuret groups.
BACKGROUND OF THE INVENTION
Polymers containing alkoxy-substituted SiC-bonded biuret groups are described in German Offenlegungsschrift 22 43 628 and in Chemical Abstracts, Volume 81, 1974.
An object of the present invention is to prepare silicon compounds which contain SiC-bonded biuret groups. Another object of the present invention is to prepare silicon compounds which contain SiC-bonded biuret groups and SiOC-bonded aliphatic radicals. Still another object of the present invention is to prepare low molecular weight silicon polymers which contain SiC-bonded biuret groups and SiOC-bonded aliphatic radicals. A further object of the present invention is to provide a method for preparing monomeric or low molecular weight silicon polymers which contain SiC-bonded biuret groups and SiOC-bonded aliphatic radicals. A still further object of the present invention is to provide a method for preparing monomeric or low molecular weight silicon polymers having SiC-bonded biuret groups and SiOC-bonded aliphatic radicals in the absence of solvents.
SUMMARY OF THE INVENTION
The foregoing objects and others which will become apparent from the following description are accomplished in accordance with this invention, generally speaking, by providing silicon compounds containing SiC-bonded biuret groups and SiOC-bonded aliphatic radicals which are obtained from
(I) the addition of a silane which contains 1 or 2 silicon atoms per molecule and an SiC-bonded radical having at least one basic ##STR2## group and at least one SiOC-bonded aliphatic radical per molecule to an isocyanate selected from a monoisocyanate and/or a diisocyanate in an amount of at least 1 gram-equivalent of --NCO group per gram-equivalent of ##STR3## group present in the silane at a temperature up to 125° C. and thereafter
(II) the product obtained from Stage (I) is maintained at a temperature of from 110° C. to 125° C. for at least 2 minutes.
In another embodiment, when the amount of monoisocyanate employed from Stage (I) is less than 2 gram-equivalents of NCO groups or the amount of diisocyanate employed is less than 3 gram-equivalents of --NCO groups per gram equivalent of ##STR4## group present in the silane, then the product of Stage (I) is heated in Stage (II) to a temperature of from 110° C. to 200° C. for at least two minutes after or during the addition of additional monoisocyanate or diisocyanate.
The silicon compounds of this invention containing SiC-bonded biuret groups and SiOC-bonded aliphatic radicals are prepared by:
(I) adding a silane which contains 1 or 2 silicon atoms per molecule and an SiC-bonded radical having at least one basic ##STR5## group and at least one SiOC-bonded aliphatic radical per molecule to a monoisocyanate and/or a diisocyanate in an amount of at least 1 gram-equivalent of --NCO group per gram-equivalent of ##STR6## group present in the silane at a temperature up to 125° C. and after the addition of the silane is complete, then
(II) maintaining the product obtained from Stage (I) at a temperature of from 110° C. to 125° C. for at least 2 minutes.
In another embodiment of this invention, when the amount of monoisocyanate in Stage (I) is less than 2 gram-equivalents of --NCO groups or the amount of diisocyanate is less than 3 gram-equivalents of --NCO groups per gram-equivalent of ##STR7## group present in the silane, then the product obtained from Stage (I) is heated in Stage (II) to a temperature in the range of from 110° C. to 200° C. for at least two minutes after, or during, the addition of additional monoisocyanate or diisocyanate.
DESCRIPTION OF THE INVENTION
The silanes used in the preparation of the silicon compounds of this invention preferably have the following formula
R.sub.a X.sub.3-a SiR.sup.1 [Y(CH.sub.2).sub.b ].sub.c NR.sup.2 H
where R is the same or different hydrocarbon radicals; R 1 is the same or different divalent SiC-bonded organic radicals consisting of carbon, hydrogen and possibly basic nitrogen atoms; R 2 is hydrogen or the same or different monovalent hydrocarbon radicals or radicals of the formula
--R.sup.1 SiR.sub.a X.sub.3-a
where R, and R 1 are the same as above; X is the same or different SiOC-bonded monovalent aliphatic radicals; Y is --NR 2 --, --O-- or --S-- and a is 0, 1 or 2; b is 2, 3 or 4; and c is 0, 1, 2, 3 or 4.
Hydrocarbon radicals represented by R preferably contain from 1 to 4 carbon atoms per radical such as the methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, vinyl, allyl and methallyl radicals.
When the radicals represented by X are SiOC-bonded hydrocarbon radicals, they preferably contain from 1 to 4 carbon atoms per radical such as the methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, allyloxy, methallyloxy and isopropenyloxy radicals.
Moreover, the radicals represented by X can also be acyloxy radicals or a radical of the formula --O(CH 2 CH 2 O) n R 3 , in which R 3 is hydrogen or is the same as R and n is 1, 2, 3 or 4. The examples for hydrocarbon radicals represented by R are also equally applicable for the hydrocarbon radicals represented by R 3 . The most important example of a radical represented by X other than SiOC-bonded hydrocarbon radicals is the methoxyethyleneoxy radical.
Examples of divalent SiC-bonded organic radicals consisting of carbon, hydrogen and possibly basic nitrogen atoms, and in particular have the formula --[CH 2-d (CH 3 ) d ] m --, in which d is 0 or 1 and m is a whole number with a value of from 1 to 6, ##STR8## and the o-, m- and p-phenylene radicals.
The hydrocarbon radicals represented by R 2 can be aliphatic, cycloaliphatic or aromatic hydrocarbons, preferably having from 1 to 6 carbon atoms per radical. The hydrocarbon radicals represented by X having the SiOC-bonded hydrocarbon radicals, are also applicable for the hydrocarbon radicals represented by R 2 , except for the isopropenyl radical. Other examples of hydrocarbon radicals represented by R 2 are the cyclohexyl and phenyl radicals. An example of the radical having the formula
--R.sup.1 SiR.sub.a X.sub.3-a
is a radical of the formula
--(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3.
Specific examples of silanes which can be used in the preparation of the silicon compounds of this invention in Stage (I) have the formulas
(CH 3 O) 3 SiCH 2 NH 2
CH 3 (CH 3 O) 2 SiCH 2 NH 2
(C 2 H 5 O) 3 SiCH 2 NH 2
(CH 3 ) 2 CH 3 OSiCH 2 NH 2
(n-C 3 H 7 O) 3 SiCH 2 NH 2
CH 3 (C 2 H 5 O) 2 Si(CH 2 ) 3 NH 2
(CH 3 O) 3 Si(CH 2 ) 3 NH 2
(CH 3 ) 2 C 2 H 5 OSi(CH 2 ) 3 NH 2
(C 2 H 5 O) 3 Si(CH 2 ) 3 NH 2
(CH 3 ) 2 (n-C 3 H 7 O)Si(CH 2 ) 3 NH 2
(n-C 4 H 9 O) 3 Si(CH 2 ) 3 NH 2
CH 3 (iso-C 3 H 7 O) 2 Si(CH 2 ) 3 NH 2
(C 2 H 5 O) 3 SiCH 2 C 6 H 4 NH 2
(CH 3 O) 3 Si(CH 2 ) 4 NH 2
(CH 3 O) 3 Si(CH 2 ) 3 NHCH 3
(CH 3 O) 3 Si(CH 2 ) 3 NH-n-C 6 H 13
(iso-C 3 H 7 O) 3 Si(CH 2 ) 3 NH-cyclo-C 6 H 11
(CH 3 O)(CH 3 ) 2 Si(CH 2 ) 3 NHC 6 H 5
(C 2 H 5 O) 3 SiCH 2 CH(CH 3 )NH 2
(C 2 H 5 O) 3 SiCH(CH 3 )CH 2 NH 2
(CH 3 OC 2 H 4 O) 3 Si(CH 2 ) 3 NH 2
(C 2 H 5 O) 3 Si(CH 2 ) 3 NH(CH 2 ) 2 NH 2
(CH 3 O) 3 Si(CH 2 ) 3 NH(CH 2 ) 2 NH 2
(CH 3 O) 3 Si(CH 2 ) 3 NH(CH 2 ) 2 NH(CH 2 ) 3 Si(OCH 3 ) 3 .
The monoisocyanates and/or diisocyanates used in the preparation of the silicon compounds of this invention can be the same or different. They may be aliphatic, cycloaliphatic, aromatic, alkaromatic or araliphatic monoisocyanates and/or diisocyanates. The aliphatic radicals present in the monoisocyanates and/or diisocyanates can be linear or branched and, like the cycloaliphatic, araliphatic or alkaromatic radicals present in the isocyanates, may be free of aliphatic carbon-carbon multiple bonds or may contain multiple bonds, in particular double bonds. Aside from being substituted by isocyanate groups, they may be substituted by groups which are inert with respect to the isocyanate groups, such as the epoxy or alkoxy groups or atoms, such as chlorine atoms. Preferably, the isocyanates used in the preparation of the silicon compounds of this invention contain at most 20 carbon atoms and more preferably not more than about 17 carbon atoms per molecule.
Specific examples of isocyanates which may be used in the preparation of the silicon compounds of this invention are hexamethylenediisocyanate, trimethylhexamethylenediisocyanate, diphenylmethane-4,4'-diisocyanate, allylisocyanate, phenylisocyanate, p-ethoxyphenylisocyanate, o-, p- and m-tolylisocyanate, naphthylenediisocyanates and toluylenediisocyanates. The preferred isocyanates are the aliphatic diisocyanates.
When the R 1 radical is free of basic nitrogen and when c is zero, the silicon compounds of this invention are prepared in Stages (I) and (II) in accordance with the following equations.
Stage (I):
R.sub.a X.sub.3-a SiR.sup.1 NR.sup.2 H+R.sup.5 (NCO).sub.2-d →R.sub.a X.sub.3-a SiR.sup.1 NR.sup.2 CONHR.sup.5 (NCO).sub.1-d
Stage (II):
R.sub.a X.sub.3-a SiR.sup.1 NR.sup.2 CONHR.sup.5 (NCO).sub.d +R.sup.5 (NCO).sub.2-d →R.sub.a X.sub.3-a SiR.sup.1 NR.sup.2 CONR.sup.5 (NCO).sub.d CONHR.sup.5 (NCO).sub.1-d
where R, R 1 , X, a and d are the same as above, R 2 is a monovalent hydrocarbon radical or a radical of the formula
R.sup.1 SiR.sub.a X.sub.3-a
and R 5 is a monovalent or divalent, substituted or unsubstituted hydrocarbon radical.
In the above equation, when R 2 is hydrogen, then the silicon compound has the formula: ##STR9##
The method of this invention can be carried out batchwise, semi-continuously or as a continuous process in a single apparatus without removing the product obtained in Stage (I) prior to initiating Stage (II).
In Stage (I) of the method of this invention, cooling may be required to prevent the temperature from exceeding 125° C. and more preferably 120° C.
Stage (II) of the method of this invention is preferably carried out at 120° C. to 170° C.
Residence times longer than one hour are not generally required in Stage (II).
When a monoisocyanate is employed, preferably 1 to 2 gram-equivalents of NCO groups are present in the mixture used in Stage (II) per gram-equivalents of HN-- group present in the silane used in Stage (I) and when a diisocyanate is employed, preferably 3 to 8 gram-equivalents of NCO groups are preferably present in the mixture used in Stage (II) per gram-equivalent of ##STR10## group present in the silane used in Stage (I). Smaller amounts often result in undesirably low yields of biuret group-containing silicon compounds. Larger amounts do not produce any advantages.
Preferably, neither a solvent nor a catalyst are used in the method of this invention.
When the silicon compounds containing the SiC-bonded biuret groups of this invention contain at least 2 NCO groups per molecule, they may be used as at least a part of the compounds containing at least 2 NCO groups per molecule in the preparation of polyurethanes.
Polyurethanes are well known in the art and are prepared by reacting an organic compound having at least two active hydrogen atoms as determined by the Zerewitinoff method with a compound containing NCO groups. Other reactants, such as chain extending agents and gas-generating materials may also be employed, depending on the particular polyurethane article desired. For example, in the formation of cellular materials, gas-generating materials, such as water, are generally incorporated in the composition.
Suitable examples of compounds containing NCO groups other than the silicon compounds of this invention are alkylene diisocyanates, e.g., hexamethylene diisocyanate and decamethylene diisocyanate, and arylene diisocyanates, e.g., phenylene diisocyanates, toluene diisocyanates and mixtures thereof.
Compounds having two or more hydrogen atoms as determined by the Zerewitinoff method are polyalkylene polyols such as polyesters, polyethers, alkylene glycols, polymercaptans, polyamines and the like.
Compounds which have been employed as catalysts or activators in the formation of polyurethanes are amines such as N-ethylmorpholine and tetramethyl-1,4-butane diamine; tin compounds such as dibutyltin di-2-ethyl hexoate, dibutyltin dilaurate, stannous-2-ethylhexoate, stannous oleate; and metal soaps such as ferrous distearate, manganous linoleate, nickel stearate, cobalt stearate, manganese stearate, ferrous linoleate and cobalt naphthenate. Preferably the silicon compounds of this invention are used in an amount of from 0.1 to 0.6 mols, calculated as the silane used in their preparation, per mol of organic diisocyanate.
Also, the silicon compounds of this invention containing SiC-bonded biuret groups may be used as additives for lacquers. These additives improve the adhesion of the lacquer to substrates such as glass, metal or organopolysiloxane elastomers. Polyurethane, epoxide and alkyd resin lacquers are examples of lacquers in which these silicon compounds may be added.
Preferably, the biuret group-containing compounds are used in the lacquers in an amount of from 0.5 to 10 percent by weight based on the weight of the lacquer to be mixed with the biuret group-containing silicon compound.
The silicon compounds of this invention containing SiC-bonded biuret groups may be incorporated into polymers other than the polyurethanes described above when they contain NCO groups or carbon-carbon double bonds. Since these silicon compounds contain SiOC-bonded aliphatic radicals, they may be incorporated into polymers which crosslink upon exposure to moisture in the air. These silicon compounds may be used in, for example, applications in which the biuret group-containing silicon compounds are a component of composites, sealant compositions including those based on organopolysiloxanes, metalpolyurethane laminates and insulating materials.
In the following examples, all parts and percentages are by weight unless otherwise specified.
EXAMPLES 1 TO 14
Preparation of the silicon compounds of the invention
Stage (I): A silane is added dropwise in the amount shown in Table I over a period of from 5 to 10 minutes to a flask containing the isocyanate shown in the table, which is equipped with a reflux condenser, addition funnel, stirrer and thermometer. The temperature of the contents of the flask increases to the temperature indicated in the table.
Stage (II): After the silane has been added, the contents of the flask are heated to the temperature and for the time indicated in the table and then rapidly cooled to room temperature.
TABLE 1__________________________________________________________________________Stage I Stage II Temp. Time rises Temp. inEx. Silane Moles Isocyanate Moles to °C. °C. minute(s)__________________________________________________________________________1 H.sub.2 N(CH.sub.2).sub.3 Si(OC.sub.2 H.sub.5).sub.3 1 HMD 2 ca. 70 155 102 " 1 " 2 ca. 70 160 103 " 1 " 2 ca. 70 150 54 " 0.25 " 1.5 ca. 70 140 105 " 0.25 TMHMD 1.5 ca. 60 150 106 " 0.25 DPMD 1.5 ca. 100 140 57 " 1 AI 6 60 125 5 (1.8 bar abs.)8 " 1 PPI 4 60 150 109 H.sub.2 N(CH.sub.2).sub.2 NH(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3 0.25 HMD 1.5 70 150 1010 " 0.25 " 1.5 75 230 111 " 0.25 " 1.75 75 160 1012 p-H.sub.2 NC.sub.6 H.sub.4 Si(OC.sub.2 H.sub.5).sub.3 1 " 2 75 165 1013 n-C.sub.6 H.sub.13 NH(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3 1 " 2 65 180 6014 CH.sub.3 NH(CH.sub.2).sub.3 Si(OC.sub.2 H.sub.5).sub.3 1 " 2 85 180 30__________________________________________________________________________ HMD = hexamethylenediisocyanate TMHMD = trimethylhexamethylenediisocyanate DPMD = diphenylmethane4,4diisocyanate AI = allylisocyanate PI = phenylisocyanate
EXAMPLES 15 TO 18
Preparation of polyurethane
A high-molecular weight diol of the type and amount indicated in Table 2, and a silicon compound containing a biuret group, prepared in accordance with the example specified and in the amount specified in Table 2, is stirred at 80° C. with a diisocyanate of the type and quantity indicated in Table 2. The mixtures thus obtained are mixed with butanediol in the quantity indicated in Table 2 and then heated in polyethylene shells, initially at 80° C. for 2.5 hours and then at 120° C. for 2.5 hours (Example 15). In Examples 16, 17 and 18 the mixtures are initially heated at 80° C. for 1 hour and then at 120° C. for 4 hours. The properties of the resultant products are shown in Table 2.
COMPARISON EXAMPLE V 1
The procedure of Example 18 is repeated except that 0.5 moles of 1,4-butanediol are substituted for the 0.252 mols of 1,4-butanediol; 1.62 mols of hexamethylenediisocyanate are substituted for the 1.35 mols of hexamethylenediisocyanate and no biuret group-containing silicon compound is used. A partially liquid product is obtained.
COMPARISON EXAMPLE V 2
The procedure of Example 16 is repeated, except that 0.262 mols of 1,4-butanediol are substituted for the 0.295 mols of butanediol; 1.44 mols of hexamethylenediisocyanate are substituted for the 1.35 mols of hexamethylenediisocyanate and 0.25 mols of n-butylamine are used instead of the biuret group-containing silicon compound. After heating, the adhesion on glass and aluminum is 0 in each case.
EXAMPLE 19
One mole of the silicon compound containing the biuret group (calculated as the silane used in its preparation) is stirred at 80° C. together with 0.476 mols of hexamethylenediisocyanate into 1 mol of ethylene glycol-adipic acid polyester in which the terminal groups are essentially HOCH 2 groups and have a molecular weight of 2000 (Polyester D 2020, Bayer, Leverkusen). The resulting mixture is mixed with 0.2 mols of 1,4-butanediol and then heated in a polyethylene shell, initially at 80° C. for 1 hour and then at 150° C. for 1.5 hours.
A hard product is obtained having good tear resistance and a satisfactory tear propagation strength.
______________________________________Adhesion after heating to N/mm.sup.2______________________________________Glass 6.8Aluminum 4.7______________________________________
EXAMPLE 20
About 0.508 mols of hexamethylenediisocyanate and 0.66 g of diazabicyclooctane are stirred at 100° C. into 1 mol of ethylene glycol-adipic acid polyester in which the terminal groups are essentially HOCH 2 groups and have a molecular weight of 2000 (Polyester D 2020, Bayer, Leverkusen). The mixture, which is still about 100° C., is added to a mixture consisting of 0.66 g of dibutyltin dilaurate, 0.2 mols of 1,4-butanediol and 1.0 mol of the silicon compound containing the biuret group, (calculated as the silane used in its preparation in accordance with Example 2). Crosslinking of the mixture is observed after approximately 50 seconds.
After approximately 1.5 hours, a tack-free, hard product is obtained having a very good tear resistance and a satisfactory to good tear propagation strength.
______________________________________Adhesion after heating to N/mm.sup.2______________________________________Glass 3.4Aluminum 3.15______________________________________
TABLE 2__________________________________________________________________________ Si Compound Con- High taining Biuret Moles 1,4- Molecular Molecular Weight Group Prepared Diisocy- butane-ExampleMoles Weight Diol of Diol Moles* In Example Number Moles anate diol__________________________________________________________________________15 0.99 Polyester** 2000 0.25 2 1.25 HMGD 0.25216 1 Polyester** 2000 0.27 2 1.35 HMGD 0.29517 1 Polyester** 2000 0.27 5 1.35 TMHMD 0.25318 1 PTHF 1000 0.27 1 1.35 HMGD 0.252__________________________________________________________________________ Adhesion after***Tear Tear Propagation*** Heating To Running Upon HeatingExample Resistance Strength Hardness Glass Aluminum at 120° C. to 180° C.__________________________________________________________________________15 Very Good Very Good Good Sat. Good Barely16 Very Good Very Good Good Sat. 0 None17 Very Good Good Good Good Good Yes18 Very Good Very Good Sat. Sat. Sat. Barely__________________________________________________________________________ Polyester**: Ethylene glycoladipic acid polyester in which the terminal groups are essentially HOCH.sub.2 (Polyester D 2020, Bayer, Leverkusen). *Calculated as silane used for its preparation. HMGD = Hexamethylene glycol diisocyanate. TMHMD = Trimethylhexamethylenediisocyanate. PTHF = Polytetrahdrofuran. ***Determined manually without a measuring instrument. Sat. = Satisfactory.
COMPARISON EXAMPLE V 3
The procedure of Example 20 is repeated, except that 1.0 mol of 1,4-butanediol and 2.6 mols of hexamethylenediisocyanate are substituted for the 0.2 mols of 1,4-butanediol, 0.508 mols of hexamethylenediisocyanate and the silicon compound containing the biuret group. Crosslinking is observed after approximately 5 minutes.
The tear resistance is satisfactory to good, the tear propagation strength is low and the adhesion on glass and aluminum after heating is 0.
EXAMPLES 21 TO 23
Addition of silicon compounds containing SiC-bonded biuret groups to a lacquer:
(a) About 45 parts of a silicon compound containing biuret groups prepared in accordance with Example 2 are mixed with 7 parts of di-2-ethylhexyltin dilaurate, 45 parts of toluene and 3 parts of polydimethylsiloxane-polyoxyethylene block copolymer.
(b) About 6 parts of the mixture prepared in (a) above are mixed with 94 parts of the lacquer indicated in Table 3. The mixture containing lacquer and additive is applied to a tack-free skin which forms over the uncrosslinked portion of the organopolysiloxane-based composition indicated in Table 3, which can be stored in the absence of moisture and is crosslinked to an elastomer upon exposure to moisture. One hour after this coating is applied, another coating of the same type is applied to this lacquer layer, except that the additive has been omitted. The results are shown in Table 3.
COMPARISON EXAMPLES V 4 , V 5 AND V 6
The procedures of Examples 21 to 23 are repeated, except that 45 parts by weight of a silane of the formula
H.sub.2 N(CH.sub.2).sub.2 NH(CH.sub.2).sub.3 Si(OC.sub.2 H.sub.5).sub.3
are substituted for the 45 parts by weight of silicon compound containing the biuret group.
The results are shown in Table 3.
TABLE 3__________________________________________________________________________Example or Type of CompositionComparison Crosslinkable to Adhesion onExample Elastomer Lacquer Coatibility elastomer.sup.+__________________________________________________________________________21 Crosslinks with the Two component Coatable Good liberation of amine polyurethane and oxime. lacquer.V.sub.4 Crosslinks with the Two component Coatable None liberation of amine polyurethane and oxime. lacquer.22 Crosslinks with the One component Coatable Good liberation of amine epoxide lac- and oxime. quer.V.sub.5 Crosslinks with the One component Coatable, but Moderate liberation of amine epoxide lac- with 5 percent and oxime. quer. uncovered sites on skin.23 Composition of the Alkyd resin Coatable Moderate above type, but with lacquer. chalk as filler.V.sub.6 Composition of the Alkyl resin Coatable Somewhat above type, but with lacquer. worse than chalk as filler. moderate.__________________________________________________________________________ (+) Good = Lacquer layer cannot be removed without damaging elastomer. Moderate = Lacquer layer can be removed only in pieces up to 1 cm.sup.2. None = Lacquer layer can be easily removed in one piece or in a few pieces. | Organosilicon compounds containing SiC-bonded biuret groups are prepared by (I) adding a silane containing 1 or 2 silicon atoms per molecule and an SiC-bonded organic radical having at least one basic ##STR1## group and at least one SiOC-bonded aliphatic radical per molecule to a monoisocyanate or a diisocycanate at a temperature up to 125° C. and (II) maintaining the temperature at 110° C. to 125° C. for at least two minutes. In an alternate procedure the silane and mono- or diisocyanate may be heated to a temperature in the range of from 110° C. up to 200° C. for at least two minutes, after or while adding additional monoisocyanate or diisocyanate.
The resultant silicon compounds are used in the preparation of polyurethanes and as additives to lacquers. | 2 |
TECHNICAL FIELD
This invention concerns memory management systems for computer systems, particularly methods of trimming, or reducing, working sets.
BACKGROUND OF THE INVENTION
Personal computers allow users to do an almost unlimited number of tasks. Examples include drafting term papers and letters, organizing recipes and addresses, tracking checking accounts and stock portfolios, communicating via electronic mail with other computer users, and drawing blueprints for home improvements. To accomplish these and other tasks, the typical computer system includes application programs—specific sets of instructions—that work with other components of the computer system to provide specific functions. Application programs are often called software to distinguish from the physical equipment, or hardware, of a computer system.
The computer system typically includes a processor, a short-term memory, a long-term memory, a keyboard, a visual display, and an operating system. The operating system is a special kind of software that facilitates execution of application programs. Application programs logically combine functions or services of the operating system with those of the processor to achieve their more complex functions. Examples of typical operating-system functions include initial interpretation of inputs from the keyboard and managing memory for application programs.
One facet of memory management concerns the allocation of short-term memory during start up and execution of application programs. Starting an application program generally entails retrieving some instructions making up the program from a long-term memory, such as a magnetic or optical disk, and copying them into portions of a short-term memory, such as a random-access memory (RAM), before the processor begins executing the program instructions. Short-term memory devices are generally faster than long-term memory devices and allow the processor to more quickly fetch and execute individual program instructions. The short-term memory is organized typically as a set of memory pages, each having the same storage capacity, for example, 4096 bytes.
As each application program starts, a memory manager within the operating system allocates a set of short-term memory pages to each application program, with the objective of reducing the number of times the processor needs to access the slower, long-term memory during execution of the application program. The set of pages allocated, or assigned, to an application program is called its working set. As application programs execute, the memory manager detects page faults—conditions indicating that applications need certain data or program instructions initially left behind in long-term memory—and eventually expands corresponding working sets to include these data or instructions if there is sufficient short-term memory available. The amount of available short-term memory is called free memory. However, if there is insufficient free memory to allow expansion of working sets, the memory manager attempts to increase the amount of free memory by re-assigning memory pages from other working sets to free memory.
This process of re-assigning pages from working sets to free memory is known as trimming the working sets. Trimming in the Microsoft WINDOWS NT 4.0 brand operating system, for example, requires the memory manager to compare the current size of one working set to its minimum allowable size every six seconds during a free-memory shortage. When the memory manager finds a working set that is larger than its minimum allowable size and that has not had too many recent page faults, the manager trims a limited number of pages from its working set, adding the pages to free memory and thus making them available for the working sets of other application programs. If there is still a free memory shortage, the memory manager looks for the next working set that is larger than its minimum allowable sizes and trims pages from it. This process of sequentially checking for larger-than-necessary working sets repeats until the memory manager trims enough pages to end the memory shortage.
In trimming pages from a specific working set, the memory manager typically tries to trim pages that have not been accessed recently. It does this by checking the access bit for each page of a working set to see whether the page has been accessed (since the last time it was checked). If the access bit is zero, indicating that the page has not been accessed, the manager re-assigns the page to free memory. If the bit is one, indicating that the page has been accessed, the memory manager resets it to zero. (If the bit for this page is still zero the next time the manager checks the page, the memory manager will trim the page.) The memory manager then similarly checks the access bit for the next page of the working set, trimming the page if it has not been accessed or resetting the access bit to zero if it has. This page-by-page search for trimmable pages continues through the working set and onto the next working set until either enough pages have been trimmed to end the free-memory shortage or each working set has been checked. (For further details, see David A. Solomon, Inside Windows NT, Second Edition (ISBN 1-57231-677-2) pages 217-304 (1998).)
In devising the present invention, the inventors recognized that this trimming method suffers from at least two problems. First, because it lacks accurate information about the relative use of specific pages, it severely limits the rate pages can be trimmed from working sets and thus reduces how fast the operating system can respond to changing memory needs of application programs, ultimately forcing them to resort to slower, long-term memory more often than may be necessary. Second, because the method treats each working set that has trimmable pages equally and in sequence, it can sometimes incorrectly and disproportionately distribute the trimming burden across a few working sets, ignoring other working sets better suited for trimming, that is, working sets having larger numbers of pages that have not been accessed recently. Accordingly, there is a need for better ways of trimming working sets.
SUMMARY OF THE INVENTION
To address these and other needs, the inventors devised a memory management system, method, and software that facilitates faster, more intelligent trimming of working sets. Specifically, in one implementation, or embodiment, the method includes assigning working sets of memory pages to corresponding application programs; estimating numbers of memory pages eligible for trimming from the working sets; and trimming the working sets based on the estimated numbers of memory pages eligible for trimming.
In an exemplary implementation, the method entails tracking the age of the memory pages of each working set using a two-bit age counter that permits classifying the pages of each working set into four classes based on how recently they were last accessed. In this implementation, estimating the numbers of memory pages eligible for trimming includes summing the number of pages in the three oldest of the four classes. Additionally, trimming the working sets entails sorting at least some of the estimates based on magnitude and trimming working sets with larger estimates before trimming those with small ones.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an exemplary computer system 10 embodying the invention;
FIG. 2 is a partial block diagram of operating system 35 in computer system 10 , showing a trim-page estimation module 35 a and a trimming module 35 b embodying the invention;
FIG. 3 is a diagram of an exemplary data structure for a page-table entry embodying the invention.
FIG. 4 is a flowchart illustrating an exemplary method including estimating and trimming modules according to the present invention; and
FIG. 5 is a flowchart showing further details of the trimming module in the exemplary method of FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
The following detailed description, which references and incorporates FIGS. 1-5, describes and illustrates one or more exemplary embodiments of the invention. These embodiments, offered not to limit but only to exemplify and teach the invention, are shown and described in sufficient detail to enable those skilled in the art to make and use the invention. Thus, where appropriate to avoid obscuring the invention, the description may omit certain information known to those of skill in the art.
Overview
The description is organized into three sections. The first section describes an exemplary computer system implementation of the invention. The second section describes operation of the exemplary computer system, specifically how it trims working sets. And, the third section summarizes some features and advantages of the exemplary embodiment.
Exemplary Computer System Embodying the Invention
FIG. 1 shows an exemplary computer system 10 which embodies the invention. The following description of system 10 briefly and generally describes an exemplary computer hardware and computing environment for implementing the invention. However, the invention can be practiced with other computer system configurations, including hand-held devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, network personal computers (“PCs”), minicomputers, mainframe computers, and the like. The invention can also be practiced in distributed computing environments where tasks are performed by remote processing devices linked through a communications network. In a distributed computing environment, program modules can be located in both local and remote memory storage devices.
Moreover, though not required, the invention is described in the general context of computer-executable instructions, such as program modules, being executed by a computer, such as a personal computer. Generally, program modules include routines, programs, objects, components, data structures, and so forth, that perform particular tasks or implement particular abstract data types.
More particularly, computer system 10 comprises, or includes, a general purpose computing device in the form of a computer 20 , which itself includes a processing unit 21 , a system memory 22 , and a system bus 23 that operatively couples various system components, including system memory 22 , to process unit 21 . Though the exemplary embodiment includes only one processing unit, other embodiments include more than one processing unit 21 , such that the processor of computer 20 comprises a plurality of processing units, commonly referred to as a parallel-processing environment. Computer 20 can be a conventional computer, a distributed computer, or any other type of computer. Thus, the invention is not limited to a particular computer or type of computer.
System bus 23 can be any of several types of bus structures including a memory bus, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory, sometimes referred to as simply the memory, includes read-only memory (ROM) 24 and random access memory (RAM) 25 . ROM 24 stores a basic-input-output system (BIOS) 26 , containing the basic routines that help to transfer information between elements of computer 20 .
Computer system 10 further includes a hard-disk drive 27 for reading and writing information on a hard disk (not shown), a magnetic disk drive 28 for reading from or writing to a removable magnetic disk 29 , and an optical disk drive 30 for reading from or writing to a removable optical disk 31 such as a compact-disk read-only-memory (CD ROM) or other optical media. Hard-disk drive 27 , magnetic disk drive 28 , and optical disk drive 30 are connected respectively to system bus 23 by a hard-disk drive interface 32 , a magnetic disk drive interface 33 , and an optical disk drive interface 34 . These drives and their associated computer-readable media provide nonvolatile storage of computer-readable instructions, data structures, program modules and other data for computer 20 . However, any type of computer-readable media which can store data accessible by a computer, such as magnetic cassettes, flash memory cards, optical disks, Bernoulli cartridges, random-access memories (RAMs), read only memories (ROMs), and the like, can be used in the exemplary operating environment.
System 10 also includes a number of program modules stored on the hard disk, magnetic disk 29 , optical disk 31 , ROM 24 , or RAM 25 . These include an operating system 35 , one or more application programs 36 , other program modules 37 , and program data 38 . Operating system 35 provides numerous basic functions and services to application programs 36 stored by system memory 22 , hard-disk drive 27 , and/or hard-disk drive 50 of remote computer 49 . For general details on the types of functions and services, refer to the Microsoft Windows98 Resource Kit (ISBN 1-57231-644-6) or Microsoft Windows at a Glance (ISBN 1-57231-631-4) which are incorporated herein by reference. The invention, however, is not limited to a particular operating-system type or architecture. Indeed, the invention can be incorporated in any current or future operating system, for example, the Microsoft WINDOWS 98 brand operating system, the Microsoft WINDOWS NT 4.0 brand operating system, the International Business Machines Corporation OS/2 brand operating system, and the Apple Computer MACINTOSH OS brand operating system.
FIG. 2, a partial block diagram, shows that exemplary operating system 35 includes an estimation module 35 a for estimating numbers of trimmable pages (trim pages) for one or more working sets and a trim module 35 b for trimming pages based on the estimated numbers of trim pages. Although not explicitly shown in FIG. 2, the exemplary embodiment places modules 35 a and 35 b within the kernel of operating system 35 . However, other embodiments place one or more of these modules in a separate privileged process. Furthermore, still other embodiments provide a separate application program that includes one or more of the modules. The functions and exemplary implementations of the modules are explained in detail below. The functions of the invention can be grouped and replicated in numerous other ways. Thus, the invention is not limited to any particular functional division or implementation mode.
FIG. 1 also shows that computer 20 accepts user input through input devices such as a keyboard 40 and pointing device 42 . Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to processing unit 21 through a serial port interface 46 that is coupled to the system bus, but may be connected by other interfaces, such as a parallel port, game port, or a universal serial bus (USB). A monitor 47 or other type of display device is also connected to system bus 23 via an interface, such as a video adapter 48 . In addition to the monitor, computers typically include other peripheral output devices (not shown), such as speakers and printers.
Computer 20 can operate in a networked environment using logical connections to one or more remote computers, such as remote computer 49 . In this exemplary embodiment, these logical connections include a communication device coupled to computer 20 . However, the invention is not limited to a particular type of communications device. Remote computer 49 , which can be another computer, a server, a router, a network personal computer (PC), a client, a peer device, or other common network node, typically includes many or all of the elements of computer 20 . However, for clarity FIG. 1 only shows it including a memory storage device 50 . The logical connections shown in FIG. 1 include a local-area network (LAN) 51 and a wide-area network (WAN) 52 . Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet.
When used in a LAN-networking environment, computer 20 is connected to the local network 51 through a network interface or adapter 53 , which is one type of communications device. When used in a WAN-networking environment, computer 20 typically includes a modem 54 , which may be internal or external, or any other type of communications device for establishing communications over wide-area network 52 , such as the Internet. Modem 54 is connected to system bus 23 via serial port interface 46 . In a network environment, one or more of the program modules described above (or portions thereof) can be stored in the remote memory storage device. Furthermore, the illustrated network connections shown are only exemplary, and other communication means and devices for establishing a communications link between the computers may be used.
The exemplary computer can be a conventional computer, a distributed computer, or any other type of computer, since the invention is not limited to any particular computer. A distributed computer typically includes one or more processing units as its processor, and a computer-readable medium such as a memory. The computer can also include a communications device such as a network adapter or a modem, so that it is able to communicatively couple with other computers to form a computer network.
Operation of the Exemplary Computer System
The invention primarily concerns interactions among operating system 35 , application programs 36 , and RAM 24 . Generally, operating system 35 responds to selection or invocation of one or more of application programs 36 by creating one or more corresponding processes and assigning corresponding working sets of memory pages from RAM 24 . In the exemplary embodiment, each page has 4096 bytes; however, other embodiments of the invention use memory pages of smaller or larger or heterogeneous capacities. In the exemplary embodiment, once one or more working sets are assigned, age data for each page of each working set can be maintained, indicating how much time has elapsed since each page was last referenced. The age data is maintained as a two-bit count implemented in software using two extra bits in the page-table entry (PTE) for each memory page.
FIG. 3 illustrates an exemplary data structure 60 for one of these page-table entries. Data structure 60 includes 32 bits, most of which serve conventional purposes. In particular, bit 0 , the valid bit, indicates whether the page maps to a page in RAM, as opposed to a backing store, such as the hard disk; bit 1 , the write bit, indicates whether the page is read/write or read-only; bit 2 , the owner bit, indicates whether user-mode code can access the page or whether the page is limited to kernel-mode access; bit 3 , the write-through bit, enables or disables caching of writes, that is whether writes pass directly through to long-term storage or are held temporarily in short-term memory. Bit 4 indicates whether the page is cached or not. Bit 5 , the accessed bit, indicates whether the page has been read; bit 6 , the dirty bit, indicates whether the page has been written; bit 7 is reserved; bit 8 , the global bit, indicates whether a translation process was applied to all processes using this page; and bit 9 is reserved. Bits 10 and 11 , which are normally reserved, are used as the age counter. Bits 12 - 31 are used for working set page numbers. (Another embodiment combines reserved bit 9 with bits 10 and 11 to form a three-bit age counter that provides eight age states.) In practice, the exemplary embodiment combines a number of these structures, specifically one for each page of each working set, to form a novel page table structure.
Bits 10 and 11 in the exemplary page-table entry operable as a saturating two-bit counter, providing four sequential age states, with each successive state presenting a longer period of time since the associated page was last referenced. Moreover, the association of one of four age states with each page of a working set allows one to define four corresponding age bins for each working set and thus to keep track of how many pages of each working set fall into each age bin. These age counts and age bins are used within the exemplary method as illustrated in FIGS. 4 and 5.
More particularly, FIG. 4 shows an exemplary method 100 of operating computer system 10 , which includes process blocks 102 - 124 that are generally executed in parallel with other activity of processing unit 21 (shown in FIG 1 . ) Blocks 102 - 122 represent an exemplary embodiment of estimation module 35 a , and block 124 represents an exemplary embodiment of trimming module 35 b .
In block 102 , processing unit 21 sets working set counter n, which runs from one to N, to one and sample page counter m, which ranges from one to M, to one. N represents the number of application programs, processes, or tasks having assigned working sets, and M represents the number of pages for the n-th working set. After setting the working set counter and sample page counter, execution proceeds to decision block 104 .
In block 104 , processing unit 21 examines the access flag for the m-th page of the n-th working set. In the exemplary embodiment, the access flag is implemented in hardware for the physical memory page; however, in other embodiments this flag is implemented in software. If the access flag is set, indicating that the m-th memory page has been accessed for a read or write operation, execution branches to block 106 , where processing unit 21 resets the age counter for the m-th memory page. However, if the access flag is not set, indicating that the m-th memory page has not been accessed, execution branches to block 108 , and the age counter for the m-th memory page is incremented. Execution then continues to decision block 110 .
In decision block 110 , processing unit 21 determines whether the last page to be sampled in the working set has been considered. If the last sample page has not been considered, processing unit 21 increments the sample page counter based on a preselected increment that determines how many pages of each working set are considered in estimating a number of trimmable pages for the working set. The exemplary embodiment samples one-eighth, one-sixteenth, one-thirty-second, one-sixty-fourth, or one-one-hundred-twenty-eighth of the pages for each working set. The sampling can be either random or uniform. For uniform sampling, every eighth, sixteenth, thirty-secondth, sixty-fourth, or one-twenty-eighth page of a working set is considered. One can also sample every page of every working set; however, this places a considerably greater burden on processing unit 21 and may adversely affect processor performance from a user perspective. After incrementation of the sample page counter, execution returns to decision block 104 to check the access flag for the next sample page of the n-th working set.
On the other hand, if decision block 110 determines that the last sample page has been checked, execution of the exemplary method proceeds to process block 114 . In block 114 , processing unit 21 calculates an estimate for the number of pages that are eligible for trimming from the n-th working set. In the exemplary embodiment, the method includes using the following formula to estimate the number of eligible pages, or trim pages:
TrimPageEstimate[ n,t ]=min{(MaxTrimIncr+TrimPageEstimate[ n,t −1]),
(NumPagesWithAgeCount[ n , 1 ]+NumPagesWithAgeCount[ n , 2 ]+NumPagesWithAgeCount[ n , 3 ])},
where n denotes the n-th working set, t denotes the current time, t−1 denotes the previous trim cycle, min{a,b} denotes the minimum of a and b, and MaxTrimIncr denotes the maximum allowable trim increment. In addition, NumPagesWithAgeCount[n, 1] denotes the number of pages of the n-th working set that have not been referenced for one trim cycle; NumPagesWithAgeCount[n, 2] denotes the number of pages of the n-th working set that have not been referenced for two trim cycles; and NumPagesWithAgeCount[n, 3] denotes the number of pages of the n-th working set that have not been referenced for three trim cycles. The trim cycle in the exemplary embodiment is one second; however, the invention is not so limited. Based on the equation, one can see that in the exemplary embodiment, the trim-page estimate is the minimum of the previous trim page estimate (plus a maximum trim increment) and the sum of the old, older, and oldest pages in the n-th working set. The maximum trim increment is 30 pages in the exemplary embodiment.
After computing the TrimPageEstimate for the n-th working set, processor 21 executes process block 116 . This entails resetting the sample page counter m to one and checking if the n-th working set is the last working set to be considered, as decision block 118 shows. If the n-th working set is not the last working set, processing unit 21 increments the working set counter as indicated in process block 120 . In the exemplary embodiment, the method includes sampling pages from every working set; however, one can omit working sets, for example, working sets below some minimum size. Execution of the exemplary method then returns to decision block 104 to begin sampling pages from the next working set.
If the n-th working set is the last working set, as determined in decision block 118 , execution continues to decision block 122 . In block 122 , processing unit 21 determines whether there is a sufficient number of unassigned, or free, memory pages. In the exemplary embodiment, this entails checking the current amount of free memory against a desired amount of free memory. If the current amount of free memory pages is sufficient, execution returns to process block 102 , where processing unit 21 repeats the process of sampling the pages of the working sets arid computing new trim-page estimates. If, however, there is insufficient free memory, execution branches to process block 124 , which entails trimming one or more of the working sets based on the estimates of trimmable pages.
FIG. 5 shows details of the exemplary trimming process 124 . Specifically, a process block 124 a shows that the trimming process begins by sorting the working sets based on their respective trim-page estimates. In the exemplary embodiment, processing unit 21 organizes the working sets into six trim-page categories based on descending magnitude of their trim-page estimates. The exemplary embodiment includes the following six categories: more than 400, 201-400, 101-200, 51-100, 25-50 and less than 25. However, another embodiment sorts the working sets based on their trim-page estimates in descending order from the greatest to the least, and another excludes a subset of the working sets from the sorting procedure entirely. The excluded working sets are associated with one or more application programs which are likely to suffer a user-perceivable performance penalty when subjected to trimming. An interactive computer game or other application with a focus on user input and real-time response to user input would be a candidate for exclusion from this sorting. More generally, one could also weight the sorting process so that certain applications would be more or less likely to experience trimming based on their trim-page estimates.
Execution then proceeds to process block 124 b . In block 124 b , processing unit 21 initializes or sets a working set counter i, which runs from one to N, the number of sorted working sets, to 1 and initializes or sets an age-bin counter j. Thus, trimming has two control loops, one for the sorted working sets and the other for the age bins of each working set. With these control loops, the trimming process generally entails trimming the working sets in descending order of their trim estimates, with specific pages trimmed in descending order from the oldest pages (as indicated by age-bin counts) to younger pages. (In the exemplary embodiment, the youngest pages, that is, those with an age count of zero, are not trimmed; however, other embodiments do trim these pages, but generally only after older pages have been trimmed.)
More specifically, in block 124 c , processing unit 21 trims all or a fraction of the pages from the j-th age bin of the i-th working set. The exemplary embodiment attempts to trim a number of pages from the i-th working set equivalent to 50% of the current trim-page estimate for the i-th working set.
After trimming pages from the i-th working set, execution of the exemplary method continues at process block 124 d . In decision block 124 d , processing unit 21 decides whether there is, as a result of the trimming of the i-th working set, sufficient free memory, specifically comparing the number of free pages to the desired number of free pages. If there is a sufficient number of free pages, execution branches to process block 102 in FIG. 4 . However, if there is an insufficient number of free pages, execution branches to decision block 124 f . In block 124 f , processing unit 21 determines whether the last sorted working set has been trimmed. If the last working set has not been trimmed, execution returns to process block 124 c via process block 124 g , which increments the working set counter i.
However, if the last working set has been trimmed, decision block 124 f branches execution to decision block 124 h . In block 124 h , processing unit 21 determines whether pages of the last age bin, the youngest pages eligible for trimming, have been trimmed. If they have not been trimmed, execution branches to block 124 i . In block 124 i , processing unit 21 increments the age-bin counter from the current age bin to the next oldest age bin. Block 124 i also entails resetting the working set counter, before returning execution to process block 124 c for another round of trimming from the next oldest age bin of the working sets. This process repeats until the trimming process makes sufficient memory available to satisfy the desired amount of free memory. However, if the youngest pages eligible for trimming have been trimmed, execution branches to block 124 j . In block 124 j , processing unit 121 goes through the sorted list of working gets, trimming pages regardless of age until there is sufficient free memory.
In other embodiments of the invention, the method is restricted to 4 or 5 passes through the working sets during which trim-page estimates are used as the basis for trimming. Moreover, other embodiments trim pages from more than one age-bin at a time, for example, from the second and third age bins, using the trim-page estimate as a basis.
Conclusion
In furtherance of the art, the inventors have presented an operating system which includes unique estimation and trimming modules for respectively estimating numbers of pages eligible for trimming and trimming pages based on the estimated numbers of pages. The exemplary estimation module develops estimates for trimmable by tracking ages of a sample set of pages from each working set, and the exemplary trimming module sorts the working sets based on the estimates of trimmitable pages and trims the working sets based of the magnitude of the estimates. The estimation and trimming modules and methods facilitate faster, more intelligent trimming of working sets, and thus better perfoming computer systems.
The embodiments described above are intended only to illustrate and teach one or more ways of practicing or implementing the present invention, not to restrict its breadth or scope. The actual scope of the invention, which embraces all ways of practicing or implementing the invention, is defined only by the following claims and their equivalents. | A computer system, method and computer readable medium for memory management with intelligent trimming of pages of working sets are disclosed. The computer system has memory space allocatable in chunks, known as pages, to specific application programs or processes. The pages allocated to a specific application program or process define a working set of pages for the program or process. Occasionally, a system runs short of free memory space and needs to reduce the size of working sets using a process called trimming. A trimming method is disclosed that estimates numbers of trimmable pages for working sets based upon a measure of how much time has elapsed since the memory pages were last accessed by the corresponding application program. This estimation is performed prior to the need to trim working sets, and the trimming method uses these estimates to facilitate faster and more accurate trimming and thus faster recovery from shortages of free memory. | 6 |
RELATED APPLICATION
This application is a Continuation of U.S. patent application Ser. No. 08/025,949 filed Mar. 3, 1992 by David Wilson, Jr. and entitled "Compact manipulating Device For Threaded Connectors, which application is now abandoned.
FIELD OF THE INVENTION
This invention relates to devices for applying and/or removing connectors, and, more particularly, relates to tools attachable to a power driver for manipulating threaded connectors.
BACKGROUND OF THE INVENTION
While many devices for manipulating threaded connectors have been heretofore known and/or utilized, a problem persists in their application and use when the connector to be manipulated is located in a cramped, distant or awkward to reach space, or is out of the line of sight. This has been particularly true where the threaded connector being manipulated is a line fitting (various types of which are utilized to join the ends of conduits, cables, and the like to each other or to another component in a mechanical and/or electrical system), application and use of such heretofore known devices frequently involving at least partial disassembly of associated structure or components to gain access to the line fitting and/or frequently involving some risk of damage to the fitting.
Perhaps the most common of such heretofore known devices are simple box wrenches or fitting wrenches. However, use of such standard wrenches, involving movement of the handle of the wrench through a significant arc, is not well suited to applications in cramped locations, or where a plurality of line fittings are extremely closely positioned relative to one another (at least where one does not wish to remove all fittings in a series, or row, of fittings leading to the targeted fitting). Additionally, use of these well known types of wrenches necessarily involve a "hands-on" operation, and, where a second fitting on the line associated with the fitting to be manipulated must be stabilized (for example, to avoid twisting of the line), frequently require use of two wrenches each of which must be held by the user.
Various tools have been suggested to reach fasteners located in cramped areas and/or for application with a power driver (see, for example, U.S. Pat. Nos. 3,477,318, 3,620,105, 2,578,686, 4,374,479, 4,928,559, 5,050,463 and 2,630,731), with such devices, however, likewise not providing for minimal manual manipulation of the tool during operation and/or not optimizing ease of utility, mechanical durability and thus reliability, and compactness of structure. Further improvements in such tools could thus still be utilized.
SUMMARY OF THE INVENTION
This invention provides a compact device for manipulating threaded connectors, for example a line fitting while such fitting is in place on the line, a unit for stabilizing an associated part of the threaded connector, and a socket of one piece construction rotatable in such a device with the socket including an extended portion thus allowing access of the socket to closely spaced fittings.
The device of this invention includes a socket rotatably mounted in a compact housing, is releasably engagable with a power driver, and is configured to minimize the necessity for preliminary manipulation of any of the device, the connector or the surrounding equipment or structure to achieve positioning of the device on the connector or operation of the device, to enhance durability of the components of the device and thus its reliability, and to minimize the likelihood of damaging and/or disengaging from the connector during operation. The device may include means for inhibiting rotation of the socket relative to the housing when driving power in not being applied to the device.
The socket of the device of this invention has an inner periphery and an engageable outer periphery together defining a part of a side wall, the side wall having a gap therein to allow positioning of the socket around the line by passage of the line through the gap, the gap being defined between spaced edges of the side wall and having a size between the spaced edges less than the fitting size. The inner periphery of the socket has a plurality of facets sufficient in number to prevent substantial linear, as opposed to intended rotational, movement of the socket relative to the fitting in any direction having at least a component normal to the axis of rotation of the fitting once the fitting is engaged by the socket at the inner periphery thereof.
The housing has a gap at one part thereof and drive means mounted therein for imparting rotational motion to the socket, the drive means having a portion configured to be releasably engaged with the power driver, the gaps being in register when the socket is rotated to a selected position.
The drive means is engageable with the outer periphery of the socket and includes at least a first gear rotatably mounted in the housing. A rotation inhibitor is preferably mounted in the housing and is engageable with the socket or the first gear of the drive means for preventing rotation of the socket relative to the housing when no drive power is being applied from the driver while allowing rotation when drive power is being applied.
The unit for stabilizing an associated part of the threaded connector, for example a first part of a threaded connector assembly, is configured for integrated use with a device for manipulating a second part of the connector assembly. The unit includes a head for engaging the first part of the connector assembly and a stabilizer joined with the head and received at a portion of the device which is normally stationary during manipulation of the second part of the connector assembly, thus limiting movement of the head during the manipulation of the second part of the connector assembly. The stabilizer is preferably received through at least a first aperture at the normally stationary portion of the device, the stabilizer and the aperture being configured to permit substantially non-rotational relative movement of the stationary portion of the device and the stabilizer.
It is therefore an object of this invention to provide an improved device for manipulating threaded connectors which is more compact relative to the connector to be manipulated than heretofore known devices.
It is another object of this invention to provide a device for manipulating threaded connectors which is configured to minimize the necessity of manual manipulation to achieve positioning on a connector and operation of the device.
It is another object of this invention to provide a device for manipulating threaded line fittings that is configured to enhance durability and reliability of the device.
It is still another object of this invention to provide a device releasably engageable with a power driver for manipulating threaded line fittings that includes a socket configured to minimize the likelihood of damage to the fitting and/or disengagement of the socket from the fitting during operation.
It is still another object of this invention to provide a device releasably attachable to a power driver for manipulating threaded connectors that includes means for inhibiting rotation of a socket relative to a housing when driving power is not being applied to the device.
It is yet another object of this invention to provide a unit for stabilizing a first part of a line fitting assembly, the unit being fully integrated with a device for manipulating a second part of the line fitting.
It is yet another object of this invention to provide a socket of one piece construction that is receivable in a device for manipulating line fittings and having a portion which extends a selected distance away from the device to allow access of the socket to closely spaced fittings.
It is yet another object of this invention to provide a compact device for manipulating a threaded line fitting while the fitting is in place around the line, the line fitting having a fitting size relating to a part of the fitting to be engaged by the device, the device for releasable engagement with a power driver and including a socket having an inner periphery and an engageable outer periphery together defining a part of a side wall, the side wall having a gap therein to allow positioning of the socket around the line by passage of the line through the gap, the gap being defined between spaced edges of the side wall and having a size between the spaced edges less than the fitting size, and a compact drive transfer assembly including a housing having the socket rotatably mounted therein, the housing having a gap at one part thereof, and drive means mounted in the housing for imparting rotational motion to the socket and having a portion configured to be releasably engaged with the driver, the gaps being in register when the socket is rotated to a selected position.
It is still another object of this invention to provide a compact device for manipulating a threaded line fitting while the fitting is in place around the line which includes a socket having an inner periphery and an engageable outer periphery together defining a part of a side wall, the side wall having a gap therein to allow positioning of the socket around the line, the inner periphery having a plurality of facets sufficient in number to prevent substantial linear, as opposed to intended rotational, movement of the socket relative to the fitting in any direction having at least a component normal to the axis of rotation of the fitting once the fitting is engaged by said socket at the inner periphery thereof.
It is yet another object of this invention to provide a manipulating device for threaded connectors which is attachable to a power driver, the device having a housing, a socket having an engageable outer periphery rotatably mounted in the housing, a drive transfer releasably engageable with the driver and engageable with the outer periphery of the socket for causing rotational motion thereof, the drive transfer including at least a first gear rotatably mounted in the housing, and a rotation inhibitor mounted in the housing and engageable with the socket or the first gear of the drive transfer for preventing rotation of the socket relative to the housing when no drive power is being applied from the driver while allowing rotation when drive power is being applied.
It is yet another object of this invention to provide a unit for stabilizing a first part of a threaded connector assembly, the unit for use with a device for manipulating a second part of the connector assembly, the device having a first portion that is movable for manipulating the second part of the connector assembly and a second portion that is normally relatively stationary during the manipulation, the unit comprising a head for engaging the first part of the connector assembly and a stabilizer joined with the head and received at the second portion of the device for limiting movement of the head during the manipulation of the second part of the connector assembly.
It is still another object of this invention to provide a unit for stabilizing a first part of a threaded line fitting assembly while the assembly is in place on the line, the unit for use with a device for manipulating a second part of the line fitting assembly, the device having a socket that is engagable with, and rotatable for manipulating, the second part of the line fitting assembly and a housing having the socket rotatably mounted therein and that is normally relatively stationary during the manipulation, the unit including a stabilizer joined with a head engageable with the first part of the fitting, the stabilizer received through at least a first aperture at the housing of the device for limiting rotational movement of the head during the manipulation of the second part of the line fitting assembly, the stabilizer and the aperture being configured to permit substantially non-rotational relative movement of the housing of the device and the stabilizer.
It is still another object of this invention to provide a socket of one piece construction rotatably receivable in a device for manipulating a threaded line fitting while the fitting is in place around the line, the line fitting having a fitting size relating to a part of the fitting to be engaged by the socket, the device for releasable engagement with a power driver at drive means mounted in the device for imparting rotational motion to the socket, the socket having a drivable periphery and a side wall that extends through an opening in the device with an end of the socket spaced a selected distance away from the device, the side wall having a gap therein to allow positioning of the socket around the line by passage of the line through the gap.
With these and other objects in view, which will become apparent to one skilled in the art as the description proceeds, this invention resides in the novel construction, combination, and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that changes in the precise embodiment of the herein disclosed invention are meant to be included as come within the scope of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate a complete embodiment of the invention according to the best mode so far devised for the practical application of the principles thereof, and in which:
FIG. 1 is a perspective view showing both the drive assembly and socket unit and the torque reaction unit of this invention;
FIG. 2 is an exploded view of the units of FIG. 1;
FIG. 3 is a sectional view taken through section line 3--3 of FIG. 1;
FIGS. 4A and 4B are sectional views taken through section line 4--4 of FIG. 1;
FIGS. 5A through 5C are perspective views of the torque reaction unit of FIG. 1;
FIG. 6 is a perspective view with a cutaway portion illustrating a second embodiment of the torque reaction unit of this invention;
FIG. 7 is an exploded view of another embodiment of this invention.
FIG. 8 is a partial exploded view of another embodiment of the torque reaction unit of this invention;
FIGS. 9A and 9B are front and rear, respectively, elevation illustrations of an alternative feature of the connector engaging socket of this invention;
FIG. 10 is a perspective view of the extended connector engaging socket of this invention;
FIG. 11 is a perspective view of the torque reaction unit of this invention having an attachment for utilization with the socket of FIG. 11; and
FIGS. 12A through 12C illustrate various interchangeable sockets of this invention utilizable with the drive and socket unit of this invention.
DESCRIPTION OF THE INVENTION
The preferred embodiment 15 of the device for manipulating threaded connectors is illustrated in FIGS. 1 through 4. Device 15 is shown in FIG. 1 in use to manipulate line fitting 17 around line segment 19 into engagement or disengagement with matable fitting 21 around line segment 23. Device 15 is releasably engaged with power driver 25 using flexible shaft 27 and, while usable without further attachments, employs torque reaction, or stabilizing, unit 29 of this invention to hold fitting 21 during manipulation of fitting 17 to avoid damage to line segments 21 and/or 23.
Turning to FIGS. 2, 3 and 4, device 15 includes socket 30 and drive transfer assembly 31. Drive transfer assembly 31 includes housing 33, formed by main housing body 35 and cover section 37, and gear train 38 including main drive gear 40 and linkage gears 42 and 44 for imparting rotational motion to socket 30 when driven by driver 25. Housing body 35 has indented structure 39 formed therein and openings 41, 43, 45 and 47 through rear wall 49 for housing socket 30 and drive transfer assembly 31. Cover section 37 includes openings 53, 55, 57 and 59, the corresponding openings in body 35 and cover section 37 receiving arcuate shoulders 60, 60', 62, 62', 64, 64', and 66, 66' (66' not shown but being substantially the same as 64') of socket 30 and gears 40, 42 and 44, respectively, thus eliminating any need for axles, shafts, bearings and the like.
Both cover section 37 and main body 35 include gaps 68 and 70, respectively extending from openings 59 and 47, respectively, the thus formed gap 72 in housing 33 (when assembled, utilizing, for example, machine screws 73, only 3 of which are shown in FIG. 2) corresponding in size to gap 74 formed in side wall 76 of socket 30 between spaced edges 78 and 80 thereof. Side wall 76 is defined between inner periphery 82 (which may be variously configured for receiving the connector to be manipulated, a hex fitting configuration with a plurality of facets 84 being illustrated herein) and the outer periphery of the socket which includes engagable outer periphery 86 as well as the outer periphery of shoulders 60 and 60'.
Drive gear 40 includes power driver attachment opening 88 for receipt of a rotatable shaft (such as flex shaft 27 or rigid shaft 90). Linkage gears 42 and 44 may be solid, or may be bored to provide apertures 92 and 94 where stabilizing unit 29 will be utilized. Gear 40 and socket 30 are preferably of a size relative to one another to provide gear reduction (for example, about a 20% reduction). The housing, socket and gears are preferably formed of metals, though various plastics could be utilized in some applications for some of the parts of the device. While various sizes of device 15 are employed depending upon the size of connector involved, all are compact relative to the task, compactness, as well as durability, being achieved because of the particular relationship of gap size and gear sizes and/or placement of gears.
In one particularly useful embodiment of the device, overall measurements of the device are less than about 4 cm (3.2 cm) by 6 cm (5 cm) by 1.5 cm (0.9 cm) with a gap size of about 0.8 cm. This embodiment is utilized, for example, with a 1 cm hex nut, thus providing a gap which is no more than about 75% the size of the fitting. In this manner, once the line is passed through the gap and the fitting is engaged, no non-rotational movement of the socket relative to the fitting in directions normal to the axis of rotation of the fitting can occur, sufficient facets 84 being provided to hold the fitting and socket in engagement. Thus, the likelihood of damage to and/or disengagement from the fitting is reduced during operation of the device.
Moreover, by reducing the size of the gap, linkage gears 42 and 44 can be more closely spaced while still retaining, and in fact improving, sufficient engagement with outer periphery 86 of socket 30 (two cogs being engaged by each linkage gear except during passage of gap 74, assuring a minimum of two cog engagement at all times) thereby diminishing the likelihood of damage to the gears and thus failure of the device. This may be achieved with linkage gear spacing at their nearest point substantially equal to gap size.
For example, utilizing the embodiment above discussed, the linkage gears can be positioned with the angle defined by lines extending between the axis of rotation of the socket and the axes of rotation of each of the linkage gears at about 73.66°. With about a 0.8 cm gap, the angle defined by lines extending between the axis of rotation of the socket and each of the edges of the side wall is about 48° (a ratio of about 1.5 to 1).
In accord with another aspect of this invention, means for inhibiting rotation of the socket relative to the housing when power is not being applied to the device is provided to allow for placement of the socket on the connector without free rotation thus allowing greater ease of use. Threaded ball plunger 96 is threaded into housing body 35 and includes, as is well known, ball 98 biased by spring 100. Since ball 98 is biased into engagement with gear 40 (the ball plunger could be applied to any of the gears or the socket), without power applied to rotate the gear, the gear, and thus the socket will be held in place (FIG. 4A), while application of rotary power from the driver will overcome the bias thereby allowing intended rotation of the socket (FIG. 4B).
FIGS. 1, 2 and 5A through 5C show the preferred embodiment of torque reaction unit 29 of this invention. Unit 29 includes head 102 having connector receiving slot 103 and arcuate slot 104 defined therethrough. Slot 104 receives stabilizing bars, or rods, 106 and 108 therethrough, the rods being held in place relative to one another by spacers 110 and 112 secured by retaining rings 114. This arrangement allows a range (about 120° where used with hex nuts) of motion sufficient to allow maneuvering of slot 103 into place holding connector 21 while still serving to stabilize line 23 when power is applied to the device 15 (see FIGS. 5A-5C).
Rods 106 and 108 are slidably received through apertures 92 and 94, respectively, of gears 42 and 44 at housing openings 43, 45, 55 and 57, respectively, and are secured at their ends by retainer rings 116. Since the coefficient of kinetic friction is substantially less than the coefficient of static friction, when device 15 is under power with gears 42 and 44 rotating, rods 106 and 108 will much more readily slide in apertures 92 and 94 than will head 102 (at slot 103) against fitting 21. This differential in frictional forces allows head 102 to remain in engagement with fitting 21 while fitting 17 is being applied or removed, distance variation being more readily compensated by sliding of rods 106 and 108 in apertures 92 and 94. Of course the differential can be improved by careful choice of materials forming unit 29 and gears 42 and 44.
A second embodiment 118 of the stabilizing unit of this invention is illustrated in FIG. 6. Unit 118 is similar in most regards to the unit heretofore described except for use of threaded rods 120 and 122 and provision of mating threads in threaded apertures 124 and 126. Where a level of delicacy of the operation warrants, the threads are about the same size as the threads of fitting 17/21 but reversed in direction thus providing quite precise tandem movement of fitting 17 and gears 42/44 on rods 120/122.
FIG. 7 shows another embodiment 128 of the stabilizing unit of this invention, a one piece construction incorporating head 130 and bars 132 and 134. In addition, ball plunger 136 of manipulating device 137 is positioned for engagement with linkage gear 138, and socket 140 is reconfigured with hex-shaped inner periphery 142 differently oriented (sufficient facet contact being maintained). Linkage gear 138 includes elongated shoulder 144 extending through opening 146 of cover section 148, the shoulder being threaded at its outer terminus. Thumb wheel 150 is engageable at the threaded terminus of shoulder 144 for manual rotation, and thus fine positioning, of socket 140.
FIG. 8 shows yet another embodiment 152 of the stabilizing unit wherein head 154 is fixed to stabilizing tongue 156. Tongue 156 is slidably received through slot 158 in main housing body 160 (a similarly positioned slot being positioned in the cover section, not shown) and resides in the housing in the space between linkage gears and drive gear and socket.
An alternative feature of the sockets of this invention is shown in FIGS. 9A and 9B comprising lip 162 extending radially inwardly from rear wall 163 of socket 165 (which is in all other respects like the sockets described herein). By provision of lip 162, connectors may be driven or removed (depending on orientation of the socket relative to the connector) without concern for axial disengagement of the socket and the connector during operations since relative axial movement therebetween is limited to a single direction.
FIGS. 10 and 11 show an improved line fitting socket 164 of this invention utilizable with drive transfer assembly 31 of this invention. In many regards, including gap size and provision of sufficient facets to provide self maintenance on the fitting, socket 164 is similar to socket 30. However, integral shoulder 166 of side wall 168 is elongated toward its end 170 so that, when socket 164 is received in drive assembly 31, shoulder 166 extends through opening 47 a selected distance with end 170 spaced from housing 33 (various lengths of the extended socket can be provided, for example 0.5 or greater). In this manner, awkwardly positioned and/or tightly spaced fittings may be manipulated, the only space limitation being the thickness of side wall 168, using a socket of one piece construction.
As shown in FIG. 11, where fitting and/or line stabilization is desired, a stabilizing unit as heretofore described may be utilized with extended socket 164. In such case, however, it is desirable to provide reinforcement block 173 to assure that the somewhat elongated rods 106 and 108 are not twisted, damaged or caused to bind in apertures 92 and 94. Block 173 includes opening 175 for passage of socket 164 therethrough and rotation therein, opening 175 having gap 177 opening therefrom (about equal in size to the gap in side wall 168 of the socket). Openings 179 (only one of which can be seen in FIG. 11) receive different ones of rods 106 and 108 therethrough.
While only one type of extended socket is shown, it is to be understood that many configurations for the extended part of the head could be utilized, including enlarged or diminished socket openings, unusual inner periphery configurations, and the like.
FIGS. 12A through 12C show only a few of the many configurations of attachments that could be utilized with the sockets of this invention where detent 181 is provided at terminus 183 of the socket (FIG. 12A). By providing ball plunger 185 (see FIG. 12 B) in the reduced insert 187 in the various attachments to be received in terminus 183, the ball of which is received in detent 181, interchangeable socket systems of many types and varieties can be provided. | A device for manipulating threaded connectors is disclosed, the device being particularly well suited for manipulating line fittings. The device includes a socket and compact drive assembly which are configured to assure reliable transfer of power to the socket from a driver releasably attachable with the device. The socket has a split side wall with a gap defined thereby which is smaller than the fitting to be manipulated, and has facets at the inner periphery thereof sufficient in number to prevent substantial linear movement of the socket in any direction having at least a component normal to the axis of rotation of the fitting once the fitting is engaged. A fully integrated torque reaction unit, a rotation inhibitor for stabilizing the socket relative to the housing when not under power, and various sockets and attachments are described. | 1 |
Field of the Invention
This invention relates to the protection of the environment and more particularly to the collection and disposal in an environmentally safe manner of waste oil drained from the crankcase of a vehicle.
BACKGROUND OF THE INVENTION
The collection and disposal of waste oil drained from the crankcase of an engine raise many environmental concerns since such waste oil can contaminate the soil and both surface and subterranean water. Regulatory agencies have imposed appropriate regulations upon commercial establishments, such as service stations, garages and the like, to ensure environmentally safe collection and disposal of such waste engine oil. However, it is impossible to regulate effectively the collection and disposal of waste engine oil by individual do-it-yourself maintenance persons.
There are many known practices and products which have been made available for the collection and disposal of waste engine oil to encourage environmentally safe procedures. These known practices and products range from draining an oil pan into an old pan or bucket and then funneling waste oil into a jug that is subsequently delivered to a waste oil disposal facility to waste oil collection pans with associated containers for containing and disposing of the waste oil. With these latter devices, either separate collection pans are provided for subsequent emptying of the waste oil into containers or special types of containers are required to collect and dispose of the waste oil. In either event, these known products are cumbersome to use and have not been a successful solution to the problem.
Therefore, it is an object of this invention to provide a device for collection and proper disposal of waste engine oil which is simple and easy to use and which uses readily available containers for the collection and disposal of the waste engine oil.
It is further an object of this invention to provide a device for collecting waste oil and directing it into used plastic bottles for holding and subsequent disposal.
It is also an object of this invention to provide a device of simple construction and low profile to fit underneath automobiles to allow home mechanics to collect and dispose of waste oil in an environmentally safe manner.
Other objects and advantages of the invention will become apparent upon reading the following description and appended claims, and upon reference to the accompanying drawings.
SUMMARY OF THE INVENTION
The present invention addresses and solves the problems set forth in the preceding discussion by providing a device to collect waste oil and direct it into used plastic bottles for capping and proper disposal at authorized locations like gasoline service stations or other oil recycling facilities.
The waste oil collector has a catch pan that is adapted to be placed under the oil pan of an engine for collecting oil that is drained from the engine. The catch pan has a bottom wall that is slightly inclined so that the oil preferably flows to one end of the pan. The end of the pan to which the oil flows also has at least one aperture. That aperture is threaded or has some other means for attaching a plastic bottle to that aperture. The plastic bottle is typically a used soft drink bottle. Once the oil is drained from the pan into the plastic bottle, the plastic bottle is capped and delivered to an appropriate disposal site. The collector further has legs that help support the catch pan and elevate the catch pan to a sufficient height that the oil will drain into the plastic bottle that is attached to the catch pan. Because a vehicle's oil pan typically has a relatively low clearance from the ground, the plastic bottle slopes at an angle from the catch pan and gives the system a low enough profile to be used under most vehicles.
The disclosed invention facilitates proper disposal of waste oil, and it also provides for proper disposal of used plastic bottles. Even if a gasoline station or recycling center does not have the ability to recycle plastic bottles, at least they will be properly disposed of and not littered. The disclosed waste oil collector, therefore, is a simple yet environmentally effective approach to solving waste oil and plastic bottle disposal problems.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the waste oil collector.
FIG. 2 is a side view including partial cutaway view taken along lines 2--2 of FIG. 1.
FIG. 3 is a top view of the catch pan.
FIG. 4 is a front view of the catch pan taken along lines 4--4 of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, the waste oil collection and disposal system comprises a catch pan 10 and plastic bottles 11 attached thereto. In the preferred embodiment described herein and illustrated in FIG. 1, the catch pan 10 is made of molded plastic. Other types of material may also be used, including, for instance, cardboard or similar pressed paper materials. Similarly, two plastic bottles 11 are illustrated in the preferred embodiment, however, one or more bottles may be adequate depending on the size of the plastic bottle and depending on the amount of waste oil in a given engine.
The catch pan 10 comprises side walls 12 a front wall 13 and an end wall 14 that are generally perpendicular to the bottom 15 of the catch pan. The bottom 15 of the preferred embodiment comprises a front side 16 and end side 17. Referring to FIG. 2, the front side 16 of the bottom is inclined at an acute angle to the horizontal ground level 18. The end side 17 of the bottom 15 comprises a generally flat panel that is substantially parallel with the horizontal 18. While the slope described herein is preferable, the bottom may be parallel with the horizontal or even sloping slightly in the opposite direction. Any oil remaining in the catch pan is emptied into the bottles 11 as they are stood in an upright position preparatory to disengagement and disposal as described herein.
The end side 17 of the bottom 15 further comprises scalloped portions 19 that further incline the bottom 15 to its lowest point immediately adjacent the end wall 14. The scalloped portions 19 are immediately adjacent both the end wall 14 and the side Walls 12. The bottom 15 further comprises a valley 20 that is adjacent the end wall 14 and extends from one of the scalloped portions 19 to the other. The bottom of the valley is the same depth as the lowest point of the scalloped portions.
The end wall 14 further defines two apertures 21 that are adjacent the scalloped portions 19. Adjacent the end wall 14 and integrally associated therewith, there are engagement means 22 further defining the circular aperture 21 and further comprising thread means for engaging the threads of plastic bottles 11. Thus, the aperture 21 is defined by the end wall 14 and the engagement means 22. Although not illustrated in the drawings, the engagement means may also incorporate an air passage that allows air to escape efficiently from the plastic bottle that is being filled with waste oil.
The engagement means 22 are preferred to be threaded for receiving the mouth of standard soft drink bottles. However, any releasable engagement means are envisioned, including, for instance, snap means or rubber collar means. As best seen in FIG. 2, the angle of incline of the scalloped portion 19 is continued through the aperture 21. The engagement means 22, therefore, are threaded so that a plastic bottle 11 extends down from the catch pan 10 at an angle from the horizontal base portion 17 of the bottom 15. The angle is preferably relatively slight so that the plastic bottles 11 do not require a large clearance to place the entire system under a vehicle's oil pan.
The catch pan 10 further comprises legs 23 that are attached to the catch pan at the side wall 12 for cantilever supporting the catch pan so that the oil can drain into the plastic bottles 11. The legs have a length greater than the diameter of the plastic bottle to support the catch pan at a sufficient elevation that, when the system is assembled, the end side 17 of the bottom 15 is horizontal. Once assembled, the entire system is supported by the legs 23 and the plastic bottles 11, which bottles serve as a counter balance for supporting the catch pan 10. Alternatively, the support legs are a wire band extending from a side of the catch pan, across the width of the pan and up to the other side of the catch pan. When not in use, the wire support may be rotated up so the entire catch pan is only as thick as the height of the walls of the catch pan, thus allowing easy storage of the catch pan.
In operation, the catch pan is placed under the oil pan of an engine that is to be drained of its waste oil. The oil pan screw is then removed so that waste oil will empty into the catch pan 10. The incline of the bottom 15 of the catch pan causes the oil to move to the end side of the catch pan. Further, the scalloped portions 19 draw the oil into the bottom of the catch pan next to the apertures 21. Subsequently, the oil is guided through the apertures 21 and into the plastic bottles 11. In the event that the surface underneath an automobile or other engine is uneven, then a certain amount of oil may collect and remain in the catch pan 10. That oil may be drained into the bottles by merely tilting the entire system towards the plastic bottles.
Once the waste oil has been drained into the plastic bottle, the plastic bottle is then recapped and carried to a gasoline service station or recycling center where the oil may be recycled for further uses. Similarly, the used plastic bottles may then be disposed of properly by the gasoline station or the recycling center.
While a particular embodiment of the invention has been shown, it will be understood, of course, that the invention is not limited thereto since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. It is, therefore, contemplated by the appended claims to cover any such modifications as incorporate those features which constitute the essential features of these improvements within the true spirit and the scope of the invention. | The waste oil collector has a catch pan supported in a cantilever manner by a pair of legs. Apertures are provided in an end wall of the catch pan to which bottles for collecting the drained oil are connected. The bottles extend outwardly at an incline and serve as a counterbalance for supporting the catch pan in the cantilever manner from the legs. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a ceramic electronic component and a method for manufacturing the same, and more particularly, to external electrodes of a ceramic electronic component and a method for forming the external electrodes by an electrolytic plating method.
[0003] 2. Description of the Related Art
[0004] A related multilayer ceramic capacitor includes a laminate which includes dielectric ceramic layers laminated to each other and layered internal electrodes provided along interfaces therebetween and external electrodes provided on the laminate so as to electrically connect the internal electrodes which are exposed on surfaces of the laminate. An example of this related multilayer ceramic capacitor is shown in FIG. 3 .
[0005] As shown in FIG. 3 , external electrodes are provided on surfaces of a laminate 102 at which internal electrodes 104 and internal electrodes 105 are exposed so as to electrically connect the respective internal electrodes 104 and 105 . In a typical method for forming external electrodes, a metal paste including a metal component and a glass component is applied to the surfaces at which the internal electrodes are exposed and is then fired by a heat treatment, such that paste electrode layers 106 and 107 are formed.
[0006] Subsequently, first plating layers 108 and 109 primarily including Ni are formed on surfaces of the paste electrode layers 106 and 107 , respectively, and second plating layers 110 and 111 primarily including Sn are formed on surfaces of the first plating layers 108 and 109 , respectively. That is, the external electrodes each have a three-layer structure including the paste electrode layer, the first plating layer, and the second plating layer.
[0007] The external electrodes are required to have high wettability to solder when a multilayer ceramic capacitor is mounted on a substrate using solder. At the same time, the external electrodes must function to electrically connect the internal electrodes which are electrically insulated from each other. The second plating layers 110 and 111 primarily including Sn ensure the solder wettability, and the paste electrode layers 106 and 107 electrically connect the internal electrodes. The first plating layers 108 and 109 function as underlying layers for the second plating layers 110 and 111 , respectively, in order to prevent solder leaching during solder mounting.
[0008] However, each of the paste electrode layers 106 and 107 has a relatively large thickness of approximately several tens to several hundreds of micrometers. Thus, when this multilayer ceramic capacitor is formed so that the dimensions thereof conform to a predetermined standard value, an effective volume to ensure electrostatic capacitance must be decreased in an amount corresponding to the volume required to form the paste electrode layers. On the other hand, since the plating layers each have a thickness of approximately several micrometers, if the external electrodes can be formed only from the first and the second plating layers, a greater effective volume can be ensured.
[0009] For example, a method is disclosed in Japanese Unexamined Patent Application Publication No. 63-169014 in which conductive metal layers are deposited by electroless plating over substantially the entire side wall surfaces of a laminate at which internal electrodes are exposed so as to short-circuit the respective internal electrodes exposed at the side wall surfaces. However, with this method, a bonding force of the conductive metal layer formed by electroless plating to the side wall surface is weak, and reduced reliability may occur.
[0010] In addition, in Japanese Unexamined Patent Application Publication No. 5-343259, a technique is disclosed in which external electrodes having superior adhesion are formed by forming electroless plating films including glass powder dispersed therein on bare ceramic surfaces.
[0011] However, with the method for forming external electrodes disclosed in Japanese Unexamined Patent Application Publication No. 5-343259, since the plating method is electroless plating, depending on subsequent heat treatment conditions, blisters are likely to be generated in the electroless plating film. When blisters are generated, moisture may enter therethrough, and problems, such as degradation in reliability, may arise.
[0012] Furthermore, with the above-described method for forming external electrodes, since the plating method is electroless plating, if it is attempted to co-deposit glass powder together with metal ions, there is a problem in that the glass is dissolved or is not sufficiently deposited.
SUMMARY OF THE INVENTION
[0013] To overcome the problems described above, preferred embodiments of the present invention provide a ceramic electronic component having a high effective volume and superior reliability by forming external electrodes thereof only from plating films including glass particles, and a method for manufacturing the ceramic electronic component.
[0014] A ceramic electronic component according to a preferred embodiment of the present invention includes a ceramic base body, and external electrodes provided on surfaces of the ceramic base body, and the external electrodes include electrolytic plating films including glass particles dispersed therein.
[0015] In addition, the ceramic base body may preferably be a laminate including ceramic layers laminated to each other and internal electrodes provided along interfaces between the ceramic layers, and the electrolytic plating films including glass particles dispersed therein may be arranged so as to electrically connect the internal electrodes exposed at surfaces of the laminate.
[0016] In addition, the external electrodes may preferably further include plating films on the electrolytic plating films including glass particles dispersed therein.
[0017] A method for manufacturing a ceramic electronic component according to another preferred embodiment of the present invention includes the steps of preparing a ceramic base body and a plating bath, and performing electrolytic plating on the ceramic base body using the plating bath to form electrolytic plating films including glass particles dispersed therein, and the plating bath includes metal ions or metal complexes and glass particles.
[0018] The ceramic base body may preferably be a laminate including ceramic layers laminated to each other and internal electrodes arranged along interfaces between the ceramic layers, and the electrolytic plating films including glass particles dispersed therein may preferably be arranged so as to electrically connect between the internal electrodes exposed at surfaces of the laminate.
[0019] Furthermore, the method for manufacturing a ceramic electronic component described above preferably further includes the step of, after the step of forming electrolytic plating films containing glass particles dispersed therein, performing a heat treatment at a temperature substantially equal to or greater than a softening point of the glass.
[0020] The glass particles included in the plating bath are preferably coated with a silane coupling agent.
[0021] According to preferred embodiments of the present invention, since the external electrodes are formed substantially only from the plating films, a ceramic electronic component having a high effective volume can be obtained. In addition, since the plating film is an electrolytic plating film including glass particles dispersed therein, a ceramic electronic component having a high bonding force, a small number of blisters, and superior reliability can be obtained.
[0022] In addition, when the surfaces on which the plating films are formed are surfaces at which the internal electrodes are exposed, since spaces between the ceramic layers and the internal electrodes are filled with glass particles, moisture is prevented from entering through the interfaces between the ceramic layers and the internal electrodes. Thus, a multilayer ceramic electronic component having superior reliability can be obtained.
[0023] In addition, in the method for manufacturing a ceramic electronic component according to preferred embodiments of the present invention, since the plating method is an electrolytic plating method, and a reducing agent is not necessarily used, a complicated step of performing a catalytic treatment on an underlying layer can be omitted. Furthermore, since glass particles are not likely to be dissolved in an electrolytic plating solution as compared to an electroless plating solution, the glass particles can be stably dispersed in the plating film.
[0024] In addition, in the method for manufacturing a ceramic electronic component according to preferred embodiments of the present invention, by performing a heat treatment at a temperature substantially equal to or greater than a glass softening point after the plating step, a bonding force between the glass component and the ceramic base body can be further increased, and thus, a ceramic electronic component having superior reliability can be obtained.
[0025] Furthermore, in the method for manufacturing a ceramic electronic component according to preferred embodiments of the present invention, when the glass particles included in the plating bath are coated with a silane coupling agent, the glass particles are electrified and can be efficiently co-deposited during the electrolytic plating. Thus, the content and the degree of dispersion of the glass particles included in the plating film can be easily controlled.
[0026] Other features, elements, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a cross-sectional view of a multilayer ceramic capacitor which is one example of a ceramic electronic component according to a preferred embodiment of the present invention.
[0028] FIG. 2 is an enlarged view of a first plating layer shown in FIG. 1 .
[0029] FIG. 3 is a cross-sectional view of a related multilayer ceramic capacitor.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0030] In a ceramic electronic component according to preferred embodiments of the present invention, when external electrodes are formed, plating films must be directly formed on a ceramic base body without using paste electrodes, sputtering electrodes, deposition electrodes, and other types of electrodes. In addition, the plating films are electrolytic plating films each including glass particles dispersed therein. As the ceramic electronic component according to preferred embodiments of the present invention, a multilayer ceramic capacitor is shown in FIG. 1 as an example.
[0031] According to FIG. 1 , a multilayer ceramic capacitor 1 includes a laminate 2 including dielectric ceramic layers 3 laminated to each other, internal electrodes 4 and 5 provided along interfaces between the dielectric ceramic layers, and external electrodes arranged so as to electrically connect the internal electrodes 4 exposed on one surface of the laminate 2 and between the internal electrodes 5 exposed on another surface thereof. For the formation of the external electrodes, first plating layers 6 and 7 , which are electrolytic plating films including glass particles dispersed therein, are first formed on respective surfaces of the laminate 2 at which the internal electrodes 4 and 5 are exposed, second plating layers 8 and 9 each functioning as a solder leaching resistant layer are formed on the first plating layers 6 and 7 , respectively, and third plating layers 10 and 11 which ensure solder wettability are formed on the respective second plating layers 8 and 9 . In the second plating layers 8 and 9 and the third plating layers 10 and 11 , glass particles are not necessarily dispersed. In addition, in FIG. 1 , the glass particles dispersed in the first plating layers 6 and 7 are not shown.
[0032] The external electrodes shown in FIG. 1 each preferably have a three-layer structure including the first plating layer 6 or 7 , the second plating layer 8 or 9 , and the third plating layer 10 or 11 . However, as long as the advantages of various preferred embodiments of the present invention can be achieved, the three-layer structure is not necessarily provided.
[0033] Since the third plating layers 10 and 11 shown in FIG. 1 are required to have superior wettability to solder, Sn, Au, or another suitable material, for example, is preferably used as a primary component thereof. In addition, since the second plating layers 8 and 9 are required to have an underlying-layer function to prevent solder leaching, for example, Ni is preferably used as a primary component thereof. In addition, although a primary component of the first plating layer is not particularly limited, when the affinity of the primary component onto the ceramic base body is important, for example, Cu is preferably used. Furthermore, the first plating layer and the second plating layer may preferably be replaced with a single Ni plating layer including glass particles dispersed therein, for example.
[0034] In addition, the first plating layer is not formed by electroless plating in which metal ions are deposited using a reducing agent, and instead, is formed by electrolytic plating performed by a current application treatment. Thus, a surface to be plated must at least have a conductive component thereon, and in this case, a method for using exposed ends of internal electrodes as the conductive component is preferably used. In addition, as another conductive component, for example, fine metal particles which are adhered beforehand may preferably be used.
[0035] Next, FIG. 2 is an enlarged view showing a portion in which the first plating layer 6 is formed on exposed surfaces of the internal electrodes of the laminate 2 . In FIG. 2 , the second plating layer 8 and the third plating layer 10 are not shown.
[0036] As shown in FIG. 2 , glass particles 20 are dispersed in the first plating layer 6 . Since at least some of the glass particles 20 adhere to the dielectric ceramic layers 3 , a bonding force of the first plating layer 6 is increased. Furthermore, when the glass particles 20 are filled between the interfaces of the dielectric ceramic layers 3 and the internal electrodes 4 , the intrusion of moisture, such as a plating solution, can be effectively prevented. Although the possible types of glass particles described above are not particularly limited, for example, a B—Si-based glass may preferably be used. More particularly, for example, a B—Si—Bi-based, a B—Si-alkali metal-based, a B—Si-alkali metal-(Ti, Zr)-based, a B—Si-alkaline earth metal-based, a B—Si-alkali metal-alkaline earth metal-based, a B—Si—Zn-alkali metal-based, and a B—Si-Zn-alkaline earth metal-based glass may preferably be used. In addition, the size of glass particles is preferably in the range of about 0.01 μm to about 7 μm, for example, depending upon co-deposition amount and bonding properties during heat treatment, and the content of the glass particles in the first plating layer 6 is preferably in the range of about 0.1 to about 20 percent by volume, for example.
[0037] Next, a method for manufacturing the ceramic electronic component according to a preferred embodiment of the present invention will be described with reference to the multilayer ceramic capacitor shown in FIG. 1 as an example.
[0038] In the laminate 2 before being processed by plating, the exposed internal electrodes 4 are electrically insulated from each other. First, electrolytic plating is performed, so that metal ions in a plating solution are deposited on exposed portions of the internal electrodes 4 . Subsequently, plating deposits that are formed are further grown, so that the plating deposits on the exposed portions of adjacent internal electrodes 4 are connected to each other. The deposits are further grown over substantially the entire surface at which the internal electrodes 4 are exposed, so that the first plating layer 6 having uniform and dense properties is formed directly on the surface at which the internal electrodes 4 are exposed.
[0039] The method according to preferred embodiments of the present invention may be regarded as a method using the high growing and spreading ability of plating deposits. With electrolytic plating, the dielectric ceramic layer 3 preferably has a thickness of approximately 10 μm or less, for example, to facilitate the grown plating deposits being connected to each other.
[0040] In addition, before the plating is performed, a withdrawal length of each internal electrode from the surface of the laminate at which the internal electrode 4 is exposed is preferably approximately 1 μm or less, for example. The reason for this is that when the withdrawal length is greater than approximately 1 μm, electrons are not easily supplied to the exposed portions of the internal electrodes 4 , and that plating deposits are not likely to be generated. In order to decrease the withdrawal length described above, polishing, such as sand blasting or barrel polishing, for example, may preferably be performed.
[0041] Furthermore, before the plating is performed, end portions of the internal electrodes preferably protrude from the surfaces at which the internal electrodes 4 are exposed. This may be achieved when polishing conditions of sand blasting or other suitable polishing methods are appropriately adjusted, and since portions of the internal electrodes 4 which protrude during this polishing extend in directions substantially parallel to the surfaces to be plated, the degree of plating growth necessary to connect between plating deposits formed on the end portions of adjacent internal electrodes may be reduced. In this case, the thickness of the dielectric ceramic layer is preferably approximately 20 μm or less, for example, since the grown plating deposits described above are more likely to be connected to each other.
[0042] In addition, when the first plating layers 6 and 7 are formed, the second plating layers 8 and 9 and the third plating layers 10 and 11 can be easily formed by common electrolytic plating.
[0043] Next, details of an electrolytic plating method will be described.
[0044] With electrolytic plating, for example, a method may be performed in which the laminate which is not provided with the external electrodes and a conductive medium are disposed in a container provided with electrical supply terminals and are immersed in a plating bath including metal ions or metal complexes, and electricity is then supplied to the plating bath while the container is rotated, swung, or vibrated.
[0045] In this method, if glass particles are dispersed in the plating bath, when the metal is deposited by applying electricity, the glass particles are also simultaneously deposited. In order to disperse glass particles in a plating bath, a method for appropriately stirring a plating bath may be used, for example. The concentration of the glass particles in the plating bath is preferably in the range of about 0.5 g/liter to about 50 g/liter, for example.
[0046] Furthermore, before the glass particles are dispersed in the plating bath, the glass particles are preferably coated with a silane coupling agent in advance. In this case, a deposition efficiency of the glass particles is increased, and a larger number of glass particles are co-deposited in the plating film. Thus, the content of the glass particles in the plating film can be easily controlled, and the degree of dispersion of the glass particles can also be improved. The reason for this is believed to be that since being coated with a silane coupling agent, the glass particles are positively electrified.
[0047] In addition, since being coated with a silane coupling agent, the glass particles are not likely to be dissolved in the plating bath, and as a result, the deposition behavior of the glass particles is stabilized.
[0048] When a heat treatment is performed on the laminate 2 at a temperature substantially equal to or greater than a softening point of the glass particles after the electrolytic plating films including the glass particles are formed, the glass particles in the plating films flow to the laminate side and adhere thereto, so that the bonding forces of the first plating layers 6 and 7 to the laminate are improved.
[0049] When the heat treatment described above is performed, for an electroless plating film including glass particles dispersed therein, blisters are likely to be generated. However, with the electrolytic plating film of various preferred embodiments of the present invention, even when glass particles are dispersed, and a heat treatment is performed, blisters are very unlikely to be generated.
[0050] When the ceramic electronic component according to a preferred embodiment of the present invention is the multilayer ceramic capacitor shown in FIG. 1 , the external electrodes thereof are preferably formed substantially only from the plating layers. However, paste electrodes may be provided at portions which are not directly relating to the connection between the internal electrodes. For example, when it is desired to extend the external electrode to a surface adjacent to the end surface at which the internal electrodes are exposed, a thick paste electrode may be formed on the surface described above. In this case, solder mounting can be easily performed, and in addition, moisture is effectively prevented from entering from the end portion of the plating layer.
[0051] As the ceramic electronic component according to preferred embodiments of the present invention, a multilayer ceramic capacitor is disclosed as an example. However, preferred embodiments of the present invention may also be applied to a multilayer chip inductor, a multilayer chip thermistor, and other suitable multilayer electronic components. That is, when the ceramic layers are electrically insulated from each other, a material therefor is not particularly limited. For example, instead of a dielectric ceramic, a piezoelectric ceramic, a semiconductor ceramic, and a magnetic ceramic, for example, may also preferably be used, and a ceramic including a resin may also preferably be used. In addition, preferred embodiments of the present invention may also be applied to a simple ceramic electronic component including no internal electrodes.
[0052] Furthermore, in the multilayer ceramic capacitor shown in FIG. 1 , although one pair of external electrodes is provided, preferred embodiments of the present invention may also be applied to an array type electronic component having at least two pairs of external electrodes.
[0053] Hereinafter, examples of the ceramic electronic component according to preferred embodiments of the present invention and the manufacturing method thereof will be described.
EXAMPLE 1
[0054] A laminate for a multilayer ceramic capacitor having a length of about 1.0 mm, a width of about 0.5 mm, and a thickness of about 0.5 mm was prepared. Dielectric layers were each formed from a barium titanate-based dielectric material, and internal electrodes were primarily formed of Ni. In addition, the thickness of the dielectric layer provided between adjacent internal electrodes was about 2 μm, and the thickness of the internal electrode was about 1 μm.
[0055] After the laminate was dried, a sand blasting treatment was performed using a polishing agent, so that an average protrusion length of the internal electrodes protruding from the surface of the laminate at which the internal electrodes were exposed was set to about 1 μm.
[0056] Next, a B—Si glass powder having a softening point of about 600° C. and an average particle diameter of about 1.1 μm was prepared. This glass powder was coated with an amino-based silane coupling agent.
[0057] The coated glass powder was added to a pyrophosphoric acid-based electrolytic plating bath including PYRO-SOL manufactured by Meltex Inc. to obtain a concentration of about 10 g/l and was dispersed therein by stirring at a bath temperature of about 58° C. and a pH of about 8.7.
[0058] Next, about 30 ml of the laminates were disposed in a rotary barrel having a volume of about 300 ml, and about 70 ml of solder balls having a diameter of about 0.7 mm were also disposed therein.
[0059] The rotary barrel was immersed in the plating solution, and a current of about 10 A was supplied while the rotary barrel is rotated at a speed of about 20 rpm. After about 180 minutes from the beginning of the current supply, Cu plating layers having a thickness of about 5 μm and including glass particles dispersed therein were formed on the surfaces of the laminate at which the internal electrodes were exposed.
[0060] Next, the laminates were recovered from the rotary barrel, were heated to about 700° C. at a temperature rising rate of about 5° C./minute in a nitrogen atmosphere, and were maintained for about 10 minutes.
[0061] After the laminates provided with the Cu plating films were again disposed in the rotary barrel, and the rotary barrel was immersed in a Ni plating watt bath having an adjusted pH of about 4.2 and a bath temperature of about 60° C., a current of about 10 A was supplied while the rotary barrel was rotated at a speed of about 20 rpm. After 120 minutes from the beginning of the current supply, Ni plating layers each having a thickness of about 3.0 μm were formed on the Cu plating layers.
[0062] Furthermore, after the rotary barrel receiving the laminates provided with the Ni plating films was immersed in an Sn plating bath (Sn-235 manufactured by Dipsol Chemical Co., Ltd.) having an adjusted pH of about 5.0 and a bath temperature of about 33° C., a current of about 6 A was supplied while the rotary barrel was rated at a speed of about 20 rpm. After about 60 minutes from the beginning of the current supply, Sn plating layers each having a thickness of about 3.0 μm were formed on the Ni plating layers.
[0063] With the steps described above, a multilayer ceramic capacitor provided with external electrodes made of the plating layers was obtained without forming paste electrode layers on the laminate.
[0064] When 100 samples of the multilayer ceramic capacitors were selected for evaluation, and the surfaces of the external electrodes thereof were observed by an optical microscope, no blisters were observed on these 100 samples.
[0065] In addition, after the multilayer ceramic capacitor was solder-mounted on an epoxy substrate, a stress was applied to the central portion of the side surface of multilayer ceramic capacitor, which corresponds to the plane of FIG. 1 , in a direction substantially parallel to the substrate, that is, in a direction substantially perpendicular to the plane of the figure, and a stress at which the external electrode was peeled off was regarded as the bonding force. When the average value was calculated from 10 bonding forces, a sufficient value of about 80 N was obtained.
COMPARATIVE EXAMPLE 1
[0066] The same laminate and glass particles as those of Example 1 were prepared. The glass particles were coated with a silane coupling agent by a method similar to that of Example 1.
[0067] The glass particles thus coated were added to an electroless Cu plating bath including OPC Copper T manufactured by Okuno Chemical Industries Co., Ltd. so as to have a concentration of about 30 g/l and were dispersed therein by stirring at a bath temperature of about 40° C. and a pH of about 12.
[0068] Next, about 30 ml of the laminates were disposed in a rotary barrel having a volume of about 300 ml, and about 70 ml of Ni balls having a diameter of about 0.7 mm were also disposed therein.
[0069] When the rotary barrel was immersed in the plating solution and was rotated at a speed of about 12 rpm, Cu plating layers each having a thickness of about 5 μm and including glass particles dispersed therein were formed on the surfaces of the laminate at which the internal electrodes were exposed.
[0070] Next, the laminates were recovered from the rotary barrel, were heated to about 700° C. at a temperature rising rate of about 5° C./minute in a nitrogen atmosphere, and were maintained for about 10 minutes.
[0071] As described above, the laminate provided with the Cu plating films was processed by methods similar to those of Example 1, so that Ni plating layers and Sn plating layers were formed. With the steps described above, a multilayer ceramic capacitor provided with external electrodes made of the plating layers was obtained.
[0072] When 100 samples of the multilayer ceramic capacitors were selected for evaluation, and the surfaces of the external electrodes thereof were observed by an optical microscope, blisters were observed on all of the samples.
[0073] In addition, when the bonding force of the external electrode was evaluated by the same method as that of Example 1, the average value calculated from 10 bonding forces was about 60 N.
COMPARATIVE EXAMPLE 2
[0074] Substantially the same laminate as that of Example 1 was prepared.
[0075] Cu plating layers were formed on the laminate by a method similar to that of Example 1 except that no glass particles were added to the plating bath.
[0076] After a heat treatment was performed for the laminate provided with the Cu plating layers under substantially the same conditions as those of Example 1, Ni plating and Sn plating were formed by methods similar to those of Example 1. With the steps as described above, a multilayer ceramic capacitor provided with external electrodes made of the plating layers was obtained.
[0077] When 100 samples of the multilayer ceramic capacitors were selected for evaluation, and the surfaces of the external electrodes were observed by an optical microscope, no blisters were observed on any of the samples.
[0078] In addition, when the bonding force of the external electrode was evaluated by the same method as that of Example 1, the average value calculated from 10 bonding forces was insufficient, such as about 40 N.
[0079] While preferred embodiments of the invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the invention. The scope of the invention, therefore, is to be determined solely by the following claims. | When external electrodes of a multilayer ceramic capacitor are formed by performing direct plating on surfaces at which internal electrodes are exposed without forming paste electrode layers, bonding forces of plating layers are relatively weak, and in addition, when glass particles are included in the plating layers, blisters are often generated. To overcome these problems, a multilayer ceramic capacitor is formed by performing electrolytic plating using a plating bath including glass particles, electrolytic plating layers including glass particles dispersed therein are formed as the external electrodes. | 2 |
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION
This invention relates to systems for transporting loads. More particularly, this invention relates to a system for portaging ships.
Ships and waterborne vessels serve purposes that aircraft and land vehicles cannot match. Moving ships, barges, and many other water borne vessels from one body of water to another or into a body of water is a daunting undertaking. Their great weight and bulk prevent most of them from being portaged. Only a few smaller landing craft may be portaged and these usually are lifted from the water by a crane, loaded on trucks or railroad cars, hauled to the next body of water, and placed in the water by a crane. Large ships and smaller craft require that the goods must be off loaded, hauled overland, and reloaded. This is time-consuming and uneconomical. In addition, the large ships also must have a second ship to load, if it is available.
Systems of canals and locks have been used to get across isthmuses or circumvent some land obstacles between navigable waters; however, these systems are few and far between, and often they may not be where they are needed. Building new canals takes too much time and is expensive. All such waterways are vulnerable to sabotage or other deliberate subversion, and conflicting politics may deny access to them when it is most needed. Consequently, water borne vessels may not be able to be where they are needed to complete a mission or task.
Thus, in accordance with this inventive concept, a need has been recognized in the state of the art for a system for portaging ships and other water borne vessels on air cushion platforms across land, marsh, bog, or other impediment, to navigable waters.
SUMMARY OF THE INVENTION
The present invention provides a transport system that portages a ship overland on a dry dock mounted on an air cushion platform. The system raises the ship from water, hauls it across other surfaces, and launches it in water.
An object of the invention is to provide a cost-effective alternative to canals.
Another object of the invention is to provide a system for transporting loads overland.
An object of the invention is to provide a system for portaging ships from one body of water to another.
Another object of the invention is to provide a system for portaging ships on an air cushion platform.
Another object of the invention is to provide a system for raising a ship from one body of water, hauling it overland, and launching it in another body of water.
Another object of the invention is to provide a system for raising a ship from one body of water, hauling it overland, and launching it in another body of water without incurring excessive costs to build a roadway or creating permanent damage to the environment.
Another object of the invention is to provide a system utilizing a dry dock on an air cushion platform that is self propelled or towed to and from work sites on water, ice, swamps, tundra, or land.
Another object of the invention is to provide a system utilizing a dry dock on an air cushion vehicle to transport ships over or through ice packs to reach clear water.
Another object of the invention is to provide a system for transporting work and crane barges into swamp, tundra, and other areas that are not accessible by land vehicles or water vessels.
Another object of the invention is to provide a system for transporting barges and ships away from shore regions to land areas for off loading goods.
Another object of the invention is to provide a system made from proven constituent parts to transport ships and goods that eliminates reliance on cranes, railroads, and canals.
These and other objects of the invention will become more readily apparent from the ensuing specification when taken in conjunction with the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 isometrically shows the transporter system of this invention hauling a ship overland.
FIG. 2 is cross-sectional view of the transporter system receiving a ship in the dry dock.
FIG. 3 is an end view of the transporter system supporting the ship on inflated air bag structure in the dry dock.
FIG. 4 is an end view of the transporter system having the air cushion inflated to raise the ship above the waterline.
FIG. 5 is a side view of air cushion platform carrying ship and dry dock out of water onto the beach and being helped by a tow vehicle.
FIG. 6 shows the transporter system carrying the ship across land, ice, swamp, tundra or other surfaces.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, transport system 10 cradles ship 20, or other water borne vessel on air bag structure 38 to carry it across water and other surfaces, such as those on ice, swamps, tundra, or land. System 10 includes dry dock portion 30 that raises ship 20 above the water and air cushion platform portion 40 that generates air cushion 41 in skirt 43 to support and carry ship 20, dry dock portion 30, and air cushion platform portion 40. Air cushion platform 40 rides on air cushion 41 in accordance with established principles of well-known designs that lift heavy loads and rapidly traverse water and land.
Referring to FIG. 2, dry dock 30 is provided with ballast tanks 32 that are selectively flooded and purged to submerge and raise at least part of dry dock 30. Equipment for generating air cushion 41 may be located in upper part 42 of air cushion platform 40 which is located at and beneath deck 42a. This equipment is protected from the effects of exposure to seawater and may be activated when upper part 42 is above the surface of the water. Thus, ambient air may be drawn in through suitable openings above deck 42a to generate and duct volumes of pressurized air through passageways, or air shafts (not shown) that bypass ballast tanks 32 for air cushion 41.
Rigid wall portions 34 each upwardly extend from opposite sides of dry dock 30 along its length. Rigid wall portions 34 are on opposite sides of bay 35 which has openings at its opposite ends to permit ship 20 to enter and leave dry dock 30 from either end. Wall portions 34 have ballast tanks 36 that may be selectively flooded and purged to help submerge and raise dry dock 30. Wall portions 34 may also house machinery of air cushion platform 40 for generation of additional volumes of pressurized air which are fed through air ducts to air cushion 41. Optionally, another wall could extend between walls 34 to close off one of the openings at one of the ends. The additional wall could house more ballast tanks and equipment.
The required volumes and pressures of air to lift and transport system 10 and ship 20 can be developed by several different types of known onboard equipments and machinery. For examples, the wash of propeller fans, or the exhausts of turbojets, turbofans, or similar engines can be used to generate the volumes and pressures of air in the air cushions. This can be augmented by scooping dynamic air as transport system 10 moves forward. The dynamic air is slowed and converted from dynamic pressure to static pressure for additional lift.
Dry dock 30 may have rigid keel guide 37 to guide and stabilize ship 20 as it enters and leaves bay 35. Keel guide 37 may also help support ship 20 while it is in bay 35, but such support is primarily provided by air bag structure 38. Air bag structure 38 extends along opposite lateral sides of ship 20 in bay 35 and supports and secures ship 20 in dry dock 30 while it is being raised from the water and while it is in transit, see FIG. 3.
Air bag structure 38 may include a single flexible air bag or several smaller bags that collectively provide support for ship 20; structure 38 is coupled to a suitable source of pressurized air which may include some of the equipment and machinery of air cushion platform 40 that couples volumes of pressurized air to air cushion 41. Air bag structure 38 may be arranged to assure that sufficient quantities of air can be drawn in and delivered to the equipment and machinery to inflate structure 38 and generate air cushion 41 and may have passageways, or air shafts (not shown) to assure availability of such quantities.
By way of example, if ship 20 had a beam of 92 feet and length of 750 feet at waterline 21 and a gross tonnage of about 30,600 tons, air pressure in air bag structure 38 would be less than 1,100 pounds per square foot (7.7 pounds per square inch) to support and hold ship 20 in an upright orientation in bay 35 of dry dock 30, as shown in FIG. 3.
Supporting ship 20 by pressurized air bag structure 38, distributes the structural loads as they are distributed in the water, and ship 20 is held securely. In addition, air bag structure 38 eliminates the need for maintaining an inventory of specific shoring to fit the geometries of different ships since structure 38 accommodates a broad class of vessels. This feature further reduces the costs of dry-docking ship 20 and the times required to secure it or differently-shaped barge-like work platforms.
Air cushion platform 40 includes skirt 43 and the equipment and machinery for generation of sufficient volumes of pressurized air which were placed in upper part 42 and rigid walls 34 to keep them out of the water. Skirt 43 depends from the periphery 40a of air cushion platform 40 to generate and define air cushion 41. Skirt 43 may be made up from panels, or a multitude of fingers or pericells that have appropriate flexible, semi-flexible, or pliable properties that cooperate to further assure generation and definition of air cushion 41. Skirt 43 is in an uninflated, or unpressurized condition in FIGS. 2 and 3 and hangs from platform 40 as ship 20 enters bay 34 and air bag structure 38 is pressurized to support ship 20.
Referring to FIG. 4, skirt 42 is shown inflated with volumes of pressurized air distending it to fully form air cushion 41. Air cushion 41 lifts and supports the heavy loads of ship 20 and transport system 10 at the surface of the water by distributing these loads across the wide area spanned by air cushion platform 40. The shape of air cushion 41 is maintained by supplying volumes of pressurized air within ranges of relatively low air pressure. Sufficient volumes of pressurized gases are supplied to compensate for portions of these volumes that spill out around the sides of skirt 43 during support of the heavy loads and transit of system 10 across a variety of surfaces. If the same exemplary ship 20 referred to above were being transported on transport system 10 (that includes dry dock 30 and air cushion platform 40), the gross weight would be about 38,250 tons. If the dimensions of air cushion platform 40 were measured to be 125 feet wide by 800 feet long, air cushion 41 would have a pressure of 765 pounds per square foot (5.3 pounds per square inch) to raise the total weight of ship 20 and transport system 10.
Generation of sufficient volumes of pressurized air at such air pressures can be done by equipment and machinery in dry dock 30 and air cushion platform 40 so that ship 20 can be lifted, relocated and launched, and transport system 10 can be returned to its point of departure for use at a later time. The onboard equipment and machinery may adjust the volumes and pressures of air based on different total weights caused by different loads and differently sized vehicles.
Once the combined load of transport system 10 and ship 20 is supported by air cushion 41, the same or auxiliary equipment and machinery including propeller fans, turbojets, turbofans, or similar engines also can be used to propel and brake air cushion platform 40 as currently done by other ground effect vehicles. Additionally, other expedients for forward propulsion could be connected to platform 40, such as attaching cable 50a to tow vehicle 50, see FIG. 5. Other external towing or pushing systems similar to those used to tow barges on canals might be used to aid the thrust of air cushion platform 40. Thus, transport system 10 and ship 20 can go across a terrain feature or other obstacle which might otherwise block off a body of navigable water. The other propulsion equipments and systems referred to above which are external to transport system may be preferable to avoid unnecessary complications of system 10.
Referring to FIG. 6, transport system 10 progresses overland or other surfaces toward its destination, i.e. the other body of navigable water. Air cushion platform 40 proceeds from a beach onto the water, see FIGS. 5 and 4, and the pressurized air for air cushion 41 is shut off. Air cushion platform 40 settles into the water and ballast tanks 32 and 36 of dry dock 20 are partially flooded to partially submerge dry dock 30 to the extent shown in FIG. 3. Air is purged from air bag structure 38, and ship 20 is free to float or move out of dry dock 30 as shown in FIG. 2. After ship 20 is gone, this procedure is reversed to recover transport system 10 for reuse.
If transport system 10 were being used to haul a barge-like work platform to a work site on the water or on the surface of a swamp or tundra area, the pressurized air for air cushion 41 is shut off when system 10 arrives at the work site. Air cushion platform 40, dry dock 30, and the work platform settle to rest on the surface of the water, swamp, or tundra. Ballast tanks 32 and 36 are kept dry to provide buoyancy and support for the work platform until the task is completed. When the task is completed, air cushion 41 is once again inflated to raise and support transport system 10 and the work platform so they can be moved for use elsewhere.
Transport system 10 can transit land without the need for canals. If strategic canals are damaged or destroyed, transport system 10 can transit ships and heavy loads overland around the canals. Transport system 10 is a low cost alternative to canals since the costs to develop transport system 10 may be less than the costs to repair damage to existing canals or to build new ones.
Furthermore, transport system 10 reduces the cost to transport loads borne by ships over terrain. That is, a temporary hoverway could be cleared for a single transit. After transit, the surface is either restored to its natural or previous condition, or left as is. Thus, ships could be transported to an inland body of water and left there, and the terrain could be left to recover in a short time from this single transit.
Transport system 10 can transport barges or other vessels inland for off loading, as opposed to stopping at the shore to discharge their supplies. This could be advantageous in areas where oil fields lie inland in swamps or tundra or where an exposed onshore location might be vulnerable to hostile action. In addition, transporter 10 can transport ships over or through ice packs to reach clear water. Transporter system 10 could either break the ice without damage, or, simply could transit over extremely thick ice.
Having the teachings of this invention in mind, modifications and alternate embodiments of this invention may be adapted. For example, special consideration may have to be provided to make transport system 10 compatible with hostile environments, such as those found on the tundra or in polar regions. These special considerations may include, but are not limited to survival and other environmental protections that might include, means to de-ice and free the system from being frozen in place. Accordingly, appropriate subsystems would be included to keep transport system 10 operational for the tasks at hand without departing from this invention.
The disclosed components and their arrangements as disclosed herein all contribute to the novel features of this invention. This invention provides cost-effective and quickly built means to rapidly transport ships and other water vessels to and from navigable bodies of water and barge-like work platforms to otherwise inaccessible work sites. Therefore, transport system 10, as disclosed herein is not to be construed as limiting, but rather, is intended to be demonstrative of this inventive concept.
It should be readily understood that many modifications and variations of the present invention are possible within the purview of the claimed invention. It is to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described. | A transport system includes a dry dock mounted on an air cushion platform portage a ship overland. The system raises the ship from one body of water, hauls it across different surfaces, and launches it in another body of water. Ships and other water borne vessels can be portaged on air cushions across land, marsh, bog, or other impediments to navigable waters, or barge-like work platforms can be taken to work sites on water, swamps or tundra and retrieved after completion of the task. Transport system and ships can bypass canals and locks if these become inoperable, or the canals and locks can be circumvented if political conflicts deny their access. | 1 |
This is a continuation in part of the U.S. Pat. No. 4,551,383 granted on Nov. 5, 1985 to the U.S. patent application Ser. No. 06/793,160, now abandoned, which is an improvement of the same Applicant.
BACKGROUND OF THE INVENTION
In this patent there is disclosed a process for the production of padding in synthetic or other fibres, the improvement comprising the steps of:
first producing a web including a layer obtained by carding a mixture of fibres of polyester or other fibres with silicone treated fibres of diverse nature and origin;
treating one side of said web with a mixture of bonding agents of stickly plastic consistency which, when polymerised, create a very soft and elastic film;
spray-applying on the opposite side of said web from said one side thereof another type of bonding agent, of different nature, which is not sticky;
passing said web, thus treated, through a calender composed of two or more cylinders; and
heating said cylinders whereby to cause said sticky plastic bonding agent to adhere to the facing roller in the region of separation of said web from said rollers such that said layer of fibres is caused partially to separate to create air spaces therein.
By suitably regulating the pressure and the temperature of the cylinders, a desired and adjustable reduction of thickness can be obtained, and, simultaneously, the effect of the adhesion of the plastic side of the adhesive layer as the layer is being separated from the cylinder, there takes place a slight reinflation which creates an "air chamber" or air pocket within the layer.
An advantage of this process is that the formation of the air chamber or air pocket is also favoured by the presence of the silicone treated and therefore slippery fibres. This process makes it possible to reduce the desired thickness paddings having very high weight per square meter, which constitutes a considerable advantage as far as use of the padding for garments is concerned.
Another advantage is represented by the possibility of obtaining by means of the calendering operation, more or less any thickness of finished padding from a single given material starting thickness by appropriately varying the temperature and pressure of the cylinder.
In particular this process for the production of padding can be performed on webs of layers comprising a mixture of polyester or other fibres with silicone treated fibers of different nature and origin.
This mixture of fibers, by means of carding machines, is formed into a layer, which is resin bonded with a mixture of adhesives for the purpose of making it more compact and for fixing the nap.
More specifically, there are used two mixtures of adhesives: a first sticky plastic adhesive which, when polymerised, creates a very soft and elastic film on one side of the padding; on the other side, there is sprayed another type of adhesive, of different nature, which is not sticky.
The product which results from this has a soft and voluminous aspect; however, for the requirements of fashion or for other requirements, there exists the necessity of having the product in layers of high weight per square meter, and therefore of high insulating property, but reduced thickness. To achieve this the layer of padding, produced as described above, is made to pass through a calender, composed of two or more cylinders heated to a chosen temperature. In particular, one of the cylinders or of each pair of cylinders if there is more than one pair (the lower cylinder as viewed in the drawings) is completely smooth and made of metal, whilst the other is clad with a material of a different nature, which is not smooth.
By suitably adjusting the pressure and the temperature and arranging that the sticky plastic side of the layer faces towards the coated cylinder, the desired reduction in the thickness is obtained, and simultaneously, by the effect of the adhesion of the sticky plastic side of the layer itself to the cylinder in the region of separation from the cylinder, there occurs a slight reinflation which creates an "air chamber" or air pocket.
Alternatively, of course, the said calender could be constituted by entirely metal cylinders, or other non-clad materials. The presence of a layer, however thin, of adhesive, on one face of the layer, makes this latter adhere, at least over a certain section, to the facing cylinder. In practice, the expansion of the compressed material caused by this adhesion is controllable, and serves to create, in the material itself, zones of discontinuity, which reduce its specific weight and increase its thermal resistance. Thus it can be seen that the product thus obtained is able to offer a high thermal resistance without by this presenting excessive thickness.
The following table summarized, by way of example, the different insulation properties of three products, all produced starting from layers of superimposed cohered fibres of polyester, and all having the same weight per unit of surface area but of course all having different thicknesses, the thinnest being the product according to the invention of said granted U.S. Pat. No. 4,551,383.
______________________________________ Traditional Stitched Production of theProduct Wadding Wadding invention______________________________________Thickness 0,6 mm 0,6 mm 0,6 mmWeight in 30 50 120grammesInsulation 100 130 290Traditionalwadding + 100______________________________________
This above-described padding has thermal insulating characteristic which are a significant improvement over those encountered in paddings of known type which, among other things, are generally rather thick and therefore do not lend themselves well to application in the field of clothing; moreover, such known padding materials do not have such good thermal insulation characteristics as can be achieved with the padding material of the applicant's earlier patent application referred to above.
SUMMARY OF THE INVENTION
A primary object of the present invention is that of further and significantly improving the thermal insulation characteristics of the padding described hereinabove.
Another object of the invention is to provide a product which is more compact and manageable than hithertofore known padding materials.
A further object of the invention is to make available a padding material which can be used more conveniently in the field of clothing, or furnishing than prior art padding materials.
A particular object of the present invention is that of providing padding which will have exceptional thermal insulation characteristics without however relinquishing the characteristics of softness, elasticity and pleasantness to the touch typical of padding materials generally.
Yet another object of the present invention is that of providing a process which can be performed with simplicity and rapidity.
Still another object of the present invention is to provide a process for producing padding materials which allows utilisation of the products thereof which are not incompatible with their application in the field of clothing.
A still further object of the present invention is that of providing a process which leads to the production of a product which, as well as having significantly improved characteristics, is more aesthetically pleasing than previously known paddings and which, moreover, is more easily workable than prior art padding materials.
The process according to the invention for the production of padding having a high degree of thermal insulation, and which is usable in the field of clothing and furnishing comprises the steps of forming, by means of carding machines, a layer obtained from a mixture of polyester fibres with silicone treated fibres, resin coating the said layer on one side thereof with a mixture of sticky adhesives having a plastic consistency, which upon polymerisation, form a very soft and elastic film, spraying or otherwise coating, on the other side of said layer, a non sticky adhesive, calendering the thus treated layer at a variable temperature, and subsequently applying to one or both sides of said layer a further layer of metal particles embedded in synthetic resin.
Further characteristics and advantages of the process for the production of padding, which constitutes the subject of the present invention will be more clearly understood from a study of the following description, in which reference is made to the attached drawings, provided purely by way of nonlimitative example only.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a starting layer comprising a web of mixed fibres including polyester fibers and silicone treated fibres of the same or a different nature;
FIG. 2 shows the same web after the application, to one of its faces, of a layer of metal particles embedded in synthetic resin;
FIG. 3 shows the same web after the application, to the other of its faces, of a further layer of metal particles embedded in a synthetic resin;
FIGS. 4 and 5 are cross sections taken on the lines IV--IV and V--V of FIGS. 2 and 3 respectively;
FIG. 6 is a cross section showing two superimposed layers treated on one side only; and
FIG. 7 is a cross section showing two superimposed layers treated on both sides.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With particular reference to the various figures of the attached drawings, the process of the invention for the production of padding with a high degree of thermal insulation comprises the production first of a layer or web 1 obtained in accodance with the teaching of the Applicant's earlier U.S. Pat. No. 4,551,383 referred to hereinabove, and then onto this web 1 there is applied a layer 2 of metal particles embedded in synthetic resin as shown in FIG. 2. Simultaneously or sequently a second layer of metal particles embedded in a synthetic resin may be applied to the opposite face of the web 1 as shown in FIG. 3. More precisely, the or each said layer is constituted by an acrylic or polyurethane or vinyl resin, which may be in emulsion or in a solvent, pigmented with aluminium or any other metal powder, in such a way as to confer a metallised appearance to the surface of the product. If emulsions are used, these latter will be in aqueous phase, whilst if the said resins are in solution, the solvents used may be esters, ketones, dimethylformamides, aromatic hydrocarbons and the like. The said layer of resin and metallic powders may be applied on the web of padding by means of metallisation in a high vacuum, by direct or via "transfer" stamping, or by means of spreading or spraying, which may also be in direct form or by "transfer" techniques.
Direct metallisation of a surface of the padding, however, presents not insignificant practical and economic problems. Such a process, in fact, is substantially discontinuous and, moreover, the material (wadding) to be subjected to this process is very voluminois so that the length of the rolls of material which can be introduced into a conventional metallisation installation is necessarily limited and the full metallisation capacity of the installations themselves thus cannot be adequately utilised. An excessively low productivity is therefore experienced.
More advantageously a "transfer" process involving the preliminary metallisation of a film of plastic material is envisaged. Preferably a polyester film with a thickness in the region of 12-15 μm is used in such process. For this process the film is preliminarily treated with an anti-adhesive lacquer, and then the metal is applied to it by any known metallisation technique for example by spreading or spraying suitable emulsions or solutions of the desired metal particles. The metal is then transferred to the web of wadding by means of a hot calendering operation using a calender operating, for example, at a speed of around 30 m/min and at a temperature of 100°-140° C. and with a specific pressure of 10-30 mg/cm 2 . With a process such as that indicated above it is possible easily to obtain metallisation of different colours; including silver, gold and bronze, with very important aesthetic effects from a commerical point of view.
The application of a metallised layer by spreading or spraying onto a substrate is a well known technique. This comprises spreading or spraying an emulsion, or better (since this allows aesthetically more pleasing results to be obtained) a solution of resins in organic solvents in which metal pigments (generally aluminium) and organic colourants have been dispersed to impart a different colouration to the solution itself.
The most suitable resins for this purpose for the particular application of metallising onto the subject synthetic fibre wadding, are as already indicated acrylic, vinyl and polyuretane resins.
The following examples illustrates, purely by way of example, various typical solutions which may be formed by means of said resins.
______________________________________Acrylic resin:PARALOID B72 (a trademark for ppm 60 (Rohm & Haas)methyl esters of the acrylic acid)cellulose acetobutyrate ppm 90 (Bayer)metal pigment ppm 50organic pigment ppm 0-5toluene ppm 200ethyl acetate ppm 100isobutyl acetate ppm 100total solid 33%viscosity 5-10,000 cP.______________________________________
In use it will of course be necessary to bring the solid content and the viscosity to values suited to the particular system of application.
______________________________________Vinyl resin:PARALOID A30 (a trademark for ppm 10 (Rohm & Haas)methyl esters of the methacrylic acid)VINYLITE VyHH ppm 85 (Union Carbide)celllulose acetobutyrate ppm 5 (Bayer)metal pigment ppm 20toluene ppm 50methyl ethyl ketone ppm 150ethyl acetate ppm 20isobutyl acetate ppm 20total solid 33%viscosity 5-10,000 cP.Polyurethane resin:polyurethane resin ppm 35 (Larithane Ms 132)aromatic polyester (Larim S.p.A.)dimethylformamide ppm 65metal pigment ppm 50total solid 43%viscosity 8-120,000 cP.______________________________________
Whilst acrylic resins are more suitable for application by spray, vinyl and polyurethane resins lend themselves greatly to application by spreading.
Spray application is effected according to known techniques and using known spray nozzles or heads. After drying, the material is calendered to improve the aspect of the wadding, at a temperature for example of 100°-120° C. at a speed of about 30 m/min, and a pressure of 10-30 mg/cm 2 .
Application by spreading is considered more practical and more economically convenient, and in general spreading by so-called "transfer" or "off-set" techniques is preferred in that it permits more brilliant and technically more controllable and interesting results to be obtained. The technology for transfer or offset spreading is substantially known: this involves the application, to a suitably devised "release" (anti-adhesive) paper, which may have a polished, semi-polished, matt or embossed finish or other, a resin solution in the thickness considered most suitable (generally in thicknesses of 100-200 μm) using a roller-doctor blade system.
The spread layer of solution is put into contact with a web of wadding and the whole assembly passes into a drying furnace at 100°-180° C. in which the solvent is completely evaporated. At the output of the furnace the assembly is cooled; the wadding on which the resin has been deposited, by now completely dried, is separated from the release paper and would in rolls. The release paper is also wound up separately and re-utilised. The whole operation is conducted at a speed of between 10 and 50 m/min according to the type of resin and wadding and according to the desired characeristics of the finished product.
It is suitable at this point to make it clear that, whichever method of its application to the web of wadding the thickness of the layer can vary within wide limits in dependence on the final utilisation envisaged for the padding itself. Further, the metallisation operation can obviously be effected on any other type of padding for clothing and furnishing.
The layer which is obtained on the surface of the web of wadding is, preferably, several microns thick and such as to form a surface film having significant elasticity in such a way as not to prejudice in any way the typical characteristics of softness and suppleness of the padding. The application of the said surface layer is physically of significant importance in that it substantially forms a barrier layer which is largely impermeable to air from the outside (up to 80%) but such as not to retain moisture vapour or cause condensation within the layer.
The physical characteristics of the metallised layer are such that, when it is applied to the face which will be the outside of the padding (that is on the opposite face from that nearest to the body in a case in which the padding is to be utilised for clothing) it significantly reduces the transmission of heat by convection. The presence of an almost air impermeable layer, in fact, causes the creation within the layer of padding of a cushion or air pocket which remains almost static and which, consequently, constitutes a rotable thermal barrier not allowing the dispersion of heat towards the outside.
The padding thus formed also has notable improvements as far as the transmission of heat by radiation is concerned in that the layer of metal particles, preferably of aluminium, but which may be of other substances forms, in a sense, a heat reflective surface such that the heat within the padding layer is not transmitted by radiation to the outside, but reflected back towards the inside thus further increasing the insulating factor of the layer.
As far as the transmission of heat by conduction is concerned, the very small thickness of the metal particle-containing layer is such as not to cause appreciable variations in the heat transmitted by conduction.
The metallised layer which is formed on the surface of the wadding is suitably permeable to mositure so that possible condensation phenomena are avoided, which phenomena could result in the formation of condensation within the interior of the layer, which would be detrimental to the insulating properties of the padding in that the condensate would in practice fill cavities or zones which, otherwise, would be filled with air. The metallised layer, as well as being elastic and soft, thus permits any possible condensation or moisture which may form within the padding to escape therefrom thus contributing to an improvement in the health characteristics of the product.
Another important aspect of the invention is constituted by the fact that the metallised surface layer, being composed of metal particles embedded in a synthetic resin, has the function of conferring a greater compactness and dimensional stability to the padding layer thus formed, making this latter thus more easily workable (for example in the production of windcheater jackets and quilting) in that any fraying which might otherwise occur in correspondence with the cut edges is significantly reduced. Because of this the said metallised surface layer is able to facilitate the washing operations on the finished product as well as exerting a definite locking action on the surface fibres allowing the padding to be used with any type of fabric, even very light fabric, without the possibility of hairs, down or fibres escaping therefrom.
Moreover, the product obtained is very consistent, thus making it unnecessary to perform stitching through of the manufactured product, as was previously necessary in order to maintain the fabric and padding connected together.
Further, the layers of padding thus formed can be joined together in such a way as to provide a composite padding (as shown in FIGS. 6 and 7) comprising two or more layers, incorporating one or more thermal barriers within the thickness of the composite layer as well as one or more surface layer.
The presence of the metallised surface layer contributes, moreover, to improving the appearance and presentation of the product in that it presents a brilliant surface aspect due to the presence of the metal particles in the resin; the metal particles do not, however, prejudice the characteristics of softness to the tough and elasticity of padding.
From what has been explained hereinabove, and from observation of the various Figures of the attached drawings, the great functionality and practicality in use which characterises the padding of the invention will be apparent, particularly the high degree of the thermal insulation obtained by virtue of the presence of the surface layer of metal particles embedded in plastic resin.
The process of the invention has been described and illustrated hereinabove purely by way of indicative, but non-limitative example, and solely for the purpose of demonstration of the practicability and the general characteristics of the present invention, such that all those variations and modifications within the scope of an expert in the art and susceptible of being brought within the spirit and scope of the inventive concepts as defined in the following claims can be introduced thereto without departing therefrom. | A process for the production of padding layers having a high degree of thermal insulation, and particularly suitable for use in clothing and furnishing, comprises the steps of producing, by means of carding machines, a layer or web comprising a mixture of polyester fibres with silicone treated fibers of the same or different nature. This layer or web is then resin coated on one side with a mixture of sticky plastic adhesives which, when polymerized, form a very soft and elastic film; on the other side of the same layer a non-sticky adhesive is sprayed or otherwise applied and the thus treated web is then subjected to a calendering operation at a temperature varying between predetermined limits. Subsequently, a layer of metal particles embedded in synthetic resins is applied to one or both sides of the said layer in such a way as to form a thermal barrier operable to reduce the transmission of heat by radiation and convection through the layer itself. | 3 |
BACKGROUND OF THE INVENTION
The present invention relates to a power adjustment device for electric power systems, in particular for electric power systems with electric ovens.
As is known, in industrial systems comprising a plurality of electric users each whereof has its own connection times and durations, the power demands of the different users may give rise to periods of absorption equal to the maximum installed power, followed randomly by periods of low or even zero absorption, in particular when the connection and disconnection of the users are not correlated to one another.
This behaviour is disadvantageous, as it requires on one hand the availability of high power levels even when the power is not actually used, as occurs most of the time, and on the other hand it entails a penalization in terms of the costs related to the maximum available power.
The uncontrolled satisfaction of the power demands furthermore does not allow a rational management of the system.
SUMMARY OF THE INVENTION
The aim of the present invention is consequently to provide a power adjustment device for electric power systems, in particular for electric power systems with electric ovens, capable of solving the disadvantages of the known art, and in particular of optimizing the electric absorption of the system by reorganizing the power demands so as to eliminate, or at least reduce, the sequences of alternately maximum and zero absorption.
Within the scope of this aim, an object of the present invention is to provide a device capable of ensuring a constant absorption which is proximate to the average utilization value, without exceeding a preset threshold, therefore allowing the user to save on the fixed rate related to the available power.
Another object of the present invention is to provide a device which is capable of providing energy savings.
A further object of the present invention is to provide a device which is extremely flexible and adaptable to the system to be controlled and is easily modifiable to control any further users introduced into the system.
Not least object of the present invention is to provide a device which is capable of providing maximum reliability and safety, is easily applicable to existing systems and requires no particular knowledge and preparation for its use, as it entails the execution of very simple operations by its operator.
The above described aim, the objects mentioned and others which will become apparent hereinafter are achieved by a power adjustment device for electric power systems, in particular for electric power systems with electric ovens, as defined in the accompanying claims.
In particular, the power adjustment device according to the invention is based on the acknowledgement that the average power consumption of a system, e.g. an oven, in normal operating conditions is a fraction (e.g. 40%) of the maximum power, and that the operation of the system generally has very short power demand cycles. It is consequently possible to set a top power limit, close to the average used power level, and detect, store and redistribute the various random power demands, taking into account the preset power limit, so as to shift by only a few seconds the delivery of power without altering the thermal balance of the system but with considerable savings in the costs related to the available power.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of the invention will become apparent from the description of a preferred but not exclusive embodiment, illustrated only by way of non-limitative example in the accompanying drawings in the case of an electric bread-baking oven. In particular:
FIG. 1 is a general diagram of the oven equipped with the device according to the invention; and
FIGS. 2, 2a and 3 are block diagrams of the power adjustment process obtainable with the adjustment device according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference should initially be made to FIG. 1, illustrating the general diagram of the oven equipped with the adjustment device according to the invention.
In its general structure, the oven is constituted by a plurality of cooking chambers, of which only one is illustrated in the figures and is indicated by the reference numeral 1. Each cooking chamber has two distinct heating sectors, respectively in the lower part of the chamber (corresponding to the cooking level) and in its upper part, each comprising a battery or bank of resistors, respectively 2 and 3.
Each battery of resistors (hereafter referred to as a user is controlled by a respective remote control switch 4, 5 which is in turn controlled by a timer 6, 7 (with closed switch C 1 =unregulated operation) or by a control and management unit 10 (with open switch C 1 =adjusted operation according to the invention). Said timer which has the function of generating operating impulses, is connected to the control and management unit 10 which ensures the distribution of power to all the users in the different chambers according to the request and to the available power, as will become apparent hereinafter. Points C 1 (which are open during normal operation, controlled by unit 10) and C 2 (which are closed during normal operation) are switching points allowing the connection and disconnection of the various elements, depending on the system being operating with or without the control unit as already mentioned. The points C 1 and C 2 can be made, differently from what has been described and without thereby requiring switches, for example, by means of manually connectable and disconnectable bridges or deviators. Each pair of timers 6 and 7 (connected to a memory 11 resp. 12 which is internal to the control unit 10 and may be implemented e.g. by an up and down counter), is controlled by a temperature controller 13 arranged in an intermediate region of the chamber and provided with a thermometer to control the temperature in the chamber. The temperature controller 13, which is a single one for both batteries of resistors, generates a continuous signal which is fed to the timers 6, 7 which transform it into intermittent activations which are variable according to the position of a knob 9 provided on said timers according to the requirements of the user. In particular the knob allows to adjust the connection time of the resistors, therefore the average power of that specific battery of resistors which is required by the user for his own requirements, from a minimum of 20% up to stable connection, corresponding to 100%, so as to obtain in any case minimum active and disconnection times of the remote control switches not lower than 7-10 seconds.
Each chamber has a steam generator 15 controlled by its own remote control switch 16 which is in turn controlled by a thermostat 17 which is also connected to the control unit 10. In this case, however, the adjustment of the steam generator is completely assigned to its respective temperature controller (or thermostat), and the connection to the control unit merely has the function of notifying said control unit of the switch-on and switch-off times of the generator, since its operation, being prioritized, determines the cutoff of any power exceeding the preset load according to the operating cycle preset for that instant as will be explained hereinafter.
The control unit 10 is also connected, (arrows 18) to the other chambers of the oven to exchange the information required for their operation, as illustrated in the figure for chamber 1 and as will become apparent hereinafter. The control unit 10 typically comprises a microprocessor (e.g. NEC 78C10) with data and program memories (including memories 11, 12), a display controlled by an own microprocessor and a keyboard for operator dialogue, as well as a watchdog circuit to check the correct operation of the device, in a per se known manner which is therefore not illustrated. The unit 10 finally has further inputs, schematically indicated at 19 in the figure and connected to setup pushbuttons and to a key to allow programming of some parameters. In particular, according to the present embodiment, the following parameters may be set: nominal power of the resistors and of the steam generator for each individual chamber; top power limit (power not to be exceeded during the operation of the adjustment device; top power limit may be modified by an external signal which indicates the absorption of power of all other devices not directly connected to the embodiment but included in the electrical system to be controlled); extra power (top power limit replacing the preceding one, which can be set by the operator in particular instances); cycle time (cycle time of each user - two for each chamber -); alarm delay time (time after which the control unit warns the user that the set top power limit is insufficient for the correct operation of all the chambers); priority (allows to select two types of operation, with and without priority; in the first case the connection of the chambers is performed according to the order of demands, in the second the demands of the chambers having higher priorities are privileged); and priority order. The adjustment device according to the illustrated embodiment furthermore allows to select two different types of startup, i.e. slow startup, in which the users are switched on according to the demand, and quick startup, in which the adjustment device switches on all the batteries it is able to in compliance with the power limit, distributing the available power equally among the switched-on chambers. The alarm indicating insufficient power is disabled during startup and until the preset temperature is reached in all the chambers.
During normal operation the adjustment device according to the invention controls the connection and disconnection of the individual users according to the reading of the inputs and in compliance with the value of the programmed parameters as listed above. In this step the display indicates the correct operational status of the system, the values of the nominal power absorbed by the oven and the top power limit. If during this step the top power limit is such as not to allow the unit to feed all the switched-on users within the alarm delay time, the display indicates this condition so that the operator can provide the appropriate remedy or remedies.
The operation of the illustrated embodiment of the adjustment device according to the invention is now described with reference to FIGS. 2, 2a and 3.
Reference should thus be made first to FIG. 2. Initially, when the device is activated or when a specifically provided startup push button is pressed, the microprocessor initialization procedure is started to preset the inputs and the outputs and to program the display (block POWER ON). At the end of this step the program enters a step in which it waits for keyboard commands to program the power and to enable or disable priority operation, and also checks if the key which allows the user to access the programming step is inserted. In detail, after initialization, the device checks if the priority change push-button has been pressed and if this is true the device asks whether the priority operation is to be enabled or disabled and then performs the requested change. If the priority button has not been activated, the device checks if the top power limit change button has been pressed. If it has, then it asks whether normal power or extra power is to be enabled and it acquires the supplied data from keyboard. If the power button has not been activated, it checks if the startup button has been activated and, if it has, it reruns the initialization procedure; if even the startup button has not been activated, then it checks if the key has been turned and if it has it enters the programming step, in which the operator can modify the presettable parameters. Then all the preset parameters are displayed, confirmation of the data is requested and said data are then stored. Then the sequence returns to its initial point.
During the execution of the sequence shown in FIG. 2, an interrupt is generated for carrying out power adjustment according to the present invention, as schematically shown in FIG. 2a. In particular, in the instant embodiment, the interrupt, which is not enabled only during the programming step, is automatically generated by the processor every 10 ms synchronously with respect to the microprocessor clock but fully independently from the operations performed with the buttons.
The actual adjustment program, symbolized in FIG. 2a by block ADJUSTMENT and illustrated in the block diagram of FIG. 3, therefore runs every 10 ms and may be executed at any point of diagram of FIG. 2, except as said, during the programming step.
Reference should now be made to the diagram of FIG. 3, which illustrates, as mentioned, the adjustment program. At the beginning of the adjustment program the device verifies the condition of slow-startup or quick-startup operation. If the operator presets quick startup, the unit 10 increments all the users memories (hereinafter also simply termed memories) regardless of the position of the knob on the timer. In the case of slow startup the program individually scans the various inputs to check if they have submitted a request for power, and when it verifies a request it enables the memory of said battery so that it begins to increment up to the value required by the timer. At the end of this scanning of all the inputs the program starts a further scanning of all the memories to activate the related users according to the adjustment program.
In detail, for each memory the program asks if priority operation has been enabled. If it has not, it asks if the number stored in the memory is greater than the alarm time; if it is, it activates an acoustic or lightning and a display alarm and then asks if the memory is greater than the preset cycle time. If it is not, the program advances to check the reached temperature as described hereafter; if it has, the program checks if the already engaged power plus the power required by the user which is being checked at that instant exceeds the preset top power limit. If the power limit is exceeded, then the program again checks the reached battery temperatures; if the power limit is not exceeded, a second memory (hereafter named counter) of the checked battery is set equal to the cycle time supplied by the respective timer. Similarly, if priority operation is preset (the YES output of the block "PRIORITY OPERATION") the device checks if the memory has exceeded the cycle time. If it has not, the program goes to the successive memory; if it has, it checks if switching on of the user causes the total top power limit to be exceeded. If it does, the program checks if the user to be switched on has a higher priority than at least one of the users which is already on, and in this case the user with lowest priority is switched off and the total power is checked again. If the user to be switched on has a lower priority than the users already connected, the program checks the next memory. If instead after checking the power the limit is not exceeded, the memory currently being checked is set to the time supplied by the related timer, as in unprioritized operation. After this operation, regardless of the type of operation (prioritized or unprioritized) the control unit checks if the temperature controller of the chamber has sent a signal indicating that the required temperature has been reached. If it has not, the remote control switch of the user is enabled to turn on and the decrement of the controlled counter is enabled. Then the counter is checked, and if it has reached zero then turning on of the remote control switch is no longer enabled and the remote control switch is thus turned off. Then the program checks the next memory. When the chamber related to the user memory being checked has reached the temperature set by means of the temperature controller, and therefore the latter has sent the related signal indicating that the required temperature has been reached (the output of the block TEMPERATURE REACHED is YES), the program memorizes the reception of said signal, resets the memory of the two users corresponding to the chamber, resets the slow-startup operation (since by now an advanced adjustment stage has been reached) and checks if all the chambers have already reached the required temperature. If they have not, the program checks the next memory, otherwise priority operation (which is used only during the startup step to reach the preset temperatures but it is not used during normal temperature-maintaining operation) is reset and control is then returned to the push-button control loop (diagram of FIG. 2).
In practice the control unit 10, by means of the described program, cyclically checks all the users to verify the ignition demand and activate the increment of the related memories in the case of slow startup. After a time equal to the cycle time has elapsed, the control unit checks if the remaining available power is sufficient to operate the user, possibly by disconnecting one or more users according to their priority or operating time, and then the user ignition procedure is activated. When the chamber has reached the required temperature, the two related users are switched off. The continuous scanning of all the user memories every 10 ms ensures that the users are checked with a sufficient frequency and with a good redistribution of the available power, without exceeding the preset power limits. However, the various memories have a programmable alarm threshold which checks the still-loaded storage and ignition time, and if it exceeds a given value because, e.g. the related user can never be turned on it issues an alarm signal which is displayed so that the operator can intervene e.g. by turning off some not essential users or by setting a higher power limit value (extra power) or in another manner.
As can be seen from the above description, the invention fully achieves the intended objects. In fact the power adjustment device according to the invention allows to optimize the electric power absorption of the various users, distributing the available power according to the demand and priority or to the user connection time. In particular, by turning off and on the individual users according to the indicated criteria a substantially constant absorption is achieved which is close to the power consumption average, and the preset threshold is not exceeded. This is achieved by simply delaying for a few seconds the delivery of power, without altering the thermal balance of the system. However, by virtue of the invention it is possible to save on the fixed rate related to the available power. Furthermore, regarding the actual power absorption, though there should be no savings, except for a reduction in the losses on the line, it has been observed that there is an induced saving due to the greater attention requested from the operator when e.g. the power limit is exceeded, besides the fact that when the chambers reach the preset temperature the operating times still stored in the related user memories are unloaded and no longer recovered.
The device according to the invention is furthermore very easy to use, since it only requires the operator to enter the variable parameters (this entry being also executable only once permanently if there are no reasons to modify it) and it furthermore requires no complicated operations for its installation. The device can furthermore be easily modified if further controlled users are to be inserted or if some are to be excluded, as it is sufficient to change the number of users set in the program and perform the required connections for the inputs and outputs and to also replace the program so that it better suits the operating requirements of other machines. Finally, the adjustment device is reliable and requires no particular maintenance.
The invention thus conceived is susceptible to numerous modifications and variations, all of which are within the scope of the inventive concept.
It is possible to expand the field of control of the power regulation devices to cover all of the electrical plant in the laboratory, having an oven or an apparatus or a series of apparatuses to be regulated installed therein, by inserting a signal which informs the device of the power absorted by the apparatus in that moment while operating. In this way, the maximum programmed power will be that which is available at the meter and the device will assign to the oven the power that is left available by the other apparatuses during operation.
The device is not only advantageously for the utilizer, but also affords a major advantage for the power distribution agency by virtue of the fact that razionalization of the apparatuses permits the requirements of more utilizers with currently used power, thereby avoiding the need to construct new power stations.
Furthermore all the details may be replaced with other technically equivalent elements. | This power adjustment device for electric power systems, in particular for electric power systems with electric ovens, has the aim of optimizing the electric absorption of the system by reorganizing the power requests of the various users comprised in the system. The device comprises elements for detecting the power requests of a plurality of users, a control and management unit adapted to check if the available power is sufficient to feed the requesting users and to enable and disable selectively some of the users operating at that moment according to the available power and according to criteria of priority or of elapsed operating time. | 8 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to a method of manufacture of MIS (Metal Insulator Semiconductor) and MOS (Metal Oxide Semiconductor) FET (Field Effect Transistor) devices, and more particularly to a method of manufacture of Complementary MIS FET (CMIS) and Complementary MOS FET (CMOS) devices with SiGe gates.
[0002] CMIS and CMOS devices include NFET and PFET devices in doped regions in a substrate and counterdoped regions in the substrate respectively. Frequently the region in the substrate in which the PFET devices are formed comprises a counterdoped well in the substrate.
[0003] The metal part of a MISFET/MOSFET device is a conductor known as a gate electrode, hereinafter often referred to as gate. The gate electrode is composed of a material such as doped polysilicon or a metal conductor formed above the insulator of the MISFET generally referred to as the gate dielectric layer in a MISFET or gate oxide layer in a MOSFET. The gate electrode is part of a gate electrode stack that includes the gate dielectric layer which is supported on a semiconductor layer or substrate. A channel region is formed in the substrate below the gate dielectric.
[0004] A CMIS device or CMOS device includes both NFET (N-channel) devices (with source/drain regions doped with N-type dopant) devices and PFET (P-channel) devices.
[0005] A pair of source/drain regions are formed in the substrate juxtaposed with the channel region, generally aligned with the sidewalls of the gate electrode stack. The insulator of such a device is a gate dielectric which separates the gate from the semiconductor substrate upon which the gate dielectric and the gate are formed. In other words, a MIS FET or a MOS FET is a field effect transistor (FET) with a gate formed over an insulator known as a gate dielectric layer which is interposed between a channel region in the semiconductor substrate and the gate. When the gate insulator or gate dielectric insulator of a MISFET is an oxide (typically silicon oxide) the device is known as a Metal Oxide Semiconductor FET (MOSFET) device.
[0006] MISFET or MOSFET devices are typically created on the surface of a substrate after either a P-type or a N-type impurity has been implanted in the surface of the substrate, creating wells in this surface of either P-type or N-type conductivity. NMIS or NMOS devices (also referred to as n-channel devices) are, after that, created on the surface of a P-type well. In like manner, PMIS or PMOS devices (also referred to as p-channel devices) are created on the surface of an N-type well.
[0007] After the gate has been created, Lightly Doped Drain/Source (LDD/LDS) regions, commonly referred to as LDD regions, are typically implanted in the surface of the substrate, self aligned with the gate, whereby N-type impurities are used for the LDD regions of NMIS/NMOS devices and P-type impurities are used for the LDD regions of PMIS/PMOS devices, which are self aligned with the gates. After this, each of the gates is isolated by the formation of gate spacers on the sidewalls of the gates. This is followed by forming the source and drain regions of the gates which are self aligned with the spacers.
[0008] For the source/drain implants the same type impurities are used as have been used for the LDD implants. The difference between the LDD implants and the source/drain implants is that the source/drain implants are typically performed at higher implant energy and dosage that the LDD implants. In this manner the P-type implants (for PMIS/PMOS devices) of the source/drain regions (PS/D) and the n-type implants (for NMIS/NMOS devices) of the source/drain regions (NS/D) penetrate deeper into the surface of the substrate than the corresponding P-type (PLDD) and N-type (NLDD) implants for the LDD regions.
[0009] U.S. Pat. No. 6,524,902 of Rhee et al. entitled “Method of Manufacturing CMOS Semiconductor Device” points out that in the fabrication of a CMOS device, boron is doped or implanted into a polysilicon gate layer to form gates of PMOS transistors. The impurity implantation of the p-type doping impurity, e.g. boron, is often carried out along with the formation of the source/drain regions by an ion implantation process. The problem is that where boron is used as a dopant in the impurity implantation, it may diffuse and escape into P-channels through a thin gate insulating layer, unless it is insufficiently implanted or activated; and the problem is more serious because the gate insulating layer is very thin. If boron ions escape from the gate in the impurity implantation, boron concentration in the gate near to the gate insulating layer declines and the result is the problem of the Poly-Gate Depletion Effect (PDE). The manufacturing process described by Rhee et al involves blanket deposition of a polysilicon-SiGe layer, followed by formation of additional silicon cap layer formed over the polysilicon SiGe layer. Then phosphorus ions are implanted selectively into an NMOS region, but not into the PMOS region which is covered by an ion implantation mask on the silicon cap layer to cover at least one PMOS transistor region. During a subsequent thermal annealing step, the implanted N-type impurities (phosphorus ions) in the NMOS region enhance diffusion of Ge atoms into the silicon cap layer of the NMOS region, since the annealing step drives Ge atoms in both the downward and upward directions more freely as a result of the ion implantation step. The result is that a desired germanium dopant profile is produced in the SiGe layer and in the silicon layer in the NMOS transistor region, while germanium is substantially prevented from diffusing into the silicon layer in the PMOS transistor region maintaining a high level of Ge near the gate oxide.
[0010] The Abstract of an article by E. J. Stewart, M. S. Carroll, and James C. Sturm entitled “Suppression of Boron Penetration in P-Channel MOSFETs U sing Polycrystalline Si 1-x-y Ge x C y Gate Layers” in IEEE Electron Device Letters, VOL. 22, NO. 12, (December 2001) 574-576, states that “Boron penetration through thin gate oxides in p-channel MOSFETs with heavily boron-doped gates causes undesirable positive threshold voltage shifts. P-channel MOS-FETs with polycrystalline Si 1-x-y Ge x C y gate layers at the gate-oxide interface show substantially reduced boron penetration and increased threshold voltage stability compared to devices with all poly Si gates or with poly Si 1-x-y Ge x gate layers. Boron accumulates in the poly Si 1-X-Y Ge X C Y layers in the gate, with less boron entering the gate oxide and substrate. The boron in the poly Si 1-X-Y Ge X C Y appears to be electrically active, providing similar device performance compared to the poly Si or poly Si 1-X-Y Ge X C Y gated devices.”
[0011] E. J. Stewart, M. S. Carroll, and James C. Sturm entitled “Boron Segregation and electrical properties in polycrystalline Si 1-X-Y Ge X C Y and Si 1-Y C Y Layers” in Journal of Applied Physics, VOL. 95, Number 8, (15 Apr. 2004) pp. 4029-4035 “reports strong boron segregation to polycrystalline Si 1-x-y Ge x C y from polysilicon during thermal anneals . . . ” The article also states “Conventional p-channel MOSFETs with heavily boron-doped polysilicon gates can suffer from voltage instabilities, caused by diffusion from the gate through the gate oxide and into the channel during post implant anneal. Devices with polycrystalline Si 1-X-Y Ge X C Y layers in the gate have less boron penetration, and greater threshold voltage stability than devices with polycrystalline Si or Si 1-X Ge X gate layers.”
[0012] U.S. Patent Application 2004/021743 A1 of Chu entitled “High Performance FET Devices and Methods Therefor” describes a method of fabrication of FET devices in which dopant impurities are prevented from diffusing through the gate insulator. The structure comprises a Si:C, or SiGe:C, layer which is sandwiched between the gate insulator and a layer which is doped with impurities in order to provide a preselected workfunction. The Chu application states that “As the gate insulator is thinned, as dictated by the requirements of ever smaller devices, there is the problem of the doping impurities penetrating the gate insulator, typically an SiO 2 layer. For the sake of optimal device design, the gate typically is made of polysilicon, which is doped the same conductivity type as the device itself. With such doping the resultant workfunction of the gate with respect to the channel region of the device allows for the threshold of the device to be optimally set. Accordingly, N-type devices are in need of N-doped gates, and P-type devices are in need of P-doped gates. During the high temperatures of device manufacturing, the gate-doping species, most problematically boron, (B), but others like phosphorus (P) as well, readily penetrates the thin gate insulator and the result is that the gate-doping species destroys the device. The gate insulator in modern high performance devices typically needs to be less than about 3 nm thick. Preventing this dopant penetration would be an important step in achieving thinner gate insulators.”
[0013] U.S. Patent Publication 2004/0067631 of Bu et al. entitled “Reduction of Seed Layer Roughness for Use in Forming SiGe Gate Electrode” describes how to deposit a “seed” layer to facilitate deposition of a SiGe layer. The method provides for fabricating layers for use in formation of a silicon germanium (SiGe) gate starting with a substrate having a first surface. Then a gate dielectric layer is formed overlying the first surface of the substrate. Next the gate dielectric layer is treated with a gaseous medium to modify a surface characteristic of the gate dielectric. Then, a seed layer is formed overlying the treated gate dielectric thereby mitigating roughness of the seed layer. Then a SiGe layer is formed overlying the seed layer, so that the germanium (Ge) interdiffuses into the seed layer.
[0014] U.S. Pat. No. 6,709,912 of Ang et al. entitled “Dual Si—Ge Polysilicon Gate with Different Ge Concentrations for CMOS Device Optimization” describes a method for increasing the amount of Ge over a PMOS region through further implanting and laser annealing. Dual Si—Ge polysilicon gates are formed with different Ge concentrations in the fabrication of an integrated circuit device. An NMOS active area and a PMOS active area of a substrate separated by an isolation region are provided. A gate oxide layer is grown overlying the substrate in both active areas. A polycrystalline silicon-germanium (Si—Ge) layer is deposited overlying the gate oxide layer with the polycrystalline SiGe layer having a first Ge concentration. The NMOS active area is blocked while exposing the PMOS active area and performing successive cycles of Ge plasma doping and laser annealing into the PMOS active area to achieve a second Ge concentration higher than the first Ge concentration. Then, the polycrystalline Si—Ge layer is patterned to form a gate in both active areas. The gate in the PMOS active area has a higher Ge concentration than the gate in the NMOS active area. That completes formation of the dual Si—Ge polysilicon gates with different Ge concentrations in the fabrication of an integrated circuit device.
[0015] Referring again to U.S. Pat. No. 6,524,902 of Rhee et al entitled “Method of Manufacturing CMOS Semiconductor Device” the steps of the method are described next. Form a gate insulating layer on a substrate and a SiGe layer having Ge content of more than 20% on the gate insulating layer. Then form a silicon layer on the SiGe layer and form an ion implantation mask on the silicon layer to cover at least one PMOS transistor region. Perform a n-type impurity ion implantation process on at least one NMOS transistor region of the substrate having the ion implantation mask. Perform a diffusion and annealing process on the substrate in which n-type impurities are implanted to diffuse germanium into the silicon layer in the NMOS transistor region to produce a desired germanium dopant profile in the SiGe layer and the silicon layer in the NMOS transistor region, while germanium is substantially prevented from diffusing into the silicon layer in the PMOS transistor region. Then form a gate pattern for PMOS and NMOS transistors by patterning the silicon layer and the SiGe layer. The result of the process is that in the NMOS region where the presence of Ge is unwanted, some SiGe remains present.
[0016] In U.S. Pat. No. 6,730,588 of Schinella entitled “Selective deposition of SiGe” a dielectric layer is deposited on a semiconductor wafer. Then a thin silicon layer of amorphous silicon or polycrystalline silicon is deposited on the dielectric layer. A mask is formed over the thin silicon layer, which is used during etching to form a silicon nucleation layer and to expose portions of the dielectric layer. A self-aligned gate is formed by depositing a silicon germanium conducting film on the silicon nucleation layer using a material which selectively deposits on the nucleation layer and which fails to deposit on the exposed portions of the dielectric layer. Then a metal layer is deposited on the top surface of the silicon germanium conducting film. The method employed is very different from that of the present invention.
[0017] It is well known that boron activation is superior in poly-SiGe compared to that in polysilicon alone. Thus PFETs with SiGe gates can exhibit a less significant polysilicon depletion effect. The result is that there is a thinner electrical equivalent gate oxide thickness (or inversion thickness), which is beneficial for PFET drive current. In this context, thinner thickness means larger gate capacitance which directly is related to drive current.
[0018] However, N type dopant activation in the NFET region may be poorer in the presence of SiGe as evidenced by larger inversion thickness (Tinv) in NFETs with SiGe gates. As employed herein, the term “inversion thickness” (Tinv) is the electrically measured oxide thickness when a MOS device is in inversion. When Tinv is less (thinner) the gate capacitance is greater, leading to a higher drive current.
[0019] A serious problem is the “poly depletion effect” which reduces gate capacitance, with the reduced gate capacitance having the disadvantage of reducing device drive current.
SUMMARY OF THE INVENTION
[0020] It is an object of this invention to minimize the “poly depletion effect” to retain a high value of gate capacitance thereby providing a high level of device drive current.
[0021] Since SiGe and SiGeC increase the Tinv in gates of NFET devices, an object of this invention is to eliminate the presence of SiGe or SiGeC in the NFET region. In other words, an object of this invention is to provide a method for forming SiGe or SiGeC gates only in PFET devices while providing conventional polysilicon gates in NFETs.
[0022] In accordance with this invention, a method is provided for forming a SiGe or SiGeC gate solely over the PFETs by a process of initially forming a thin bilayer of a layer of silicon (Si) covered by a layer of germanium (Ge), silicon germanium (SiGe) or SiGeC over the gate dielectric layer in the early stages of formation of the gate electrode. Later in the process, the Ge, SiGe or SiGeC layer is removed from the NFET region, but is retained in the PFET region. Then the device is annealed to diffuse germanium (Ge) into the silicon layer over the PFET region. This method does not rely on implanting Ge into the gate electrode as one prior art reference describes, and minimizes the volume of the Ge, SiGe or SiGeC to avoid complications in the gate RIE process.
[0023] With the method of this invention, unlike the method of U.S. Pat. No. 6,524,902 of Rhee et al., the entire SiGe layer is etched away in from the NFET region where it is unwanted. Thus there is no SiGe or SiGeC in the NFET region, since the SiGe or SiGeC layer has been removed therefrom.
[0024] An advantage of this invention is that boron activation is enhanced by the presence of SiGe or SiGeC in the gate electrode, particularly at the interface with the gate dielectric. Since SiGe or SiGeC allows a higher level of electrical activation of boron the method of this invention minimizes the “poly depletion effect” thereby minimizing the reduction of gate capacitance and thereby avoiding reduced gate capacitance and avoiding the disadvantage of reducing device drive current.
[0025] Another advantage of this invention is that the problem often referred to as “boron penetration” in the PFET region is reduced, because the SiGe or SiGeC will retard boron diffusion.
[0026] The invention and objects and features thereof will be more readily apparent from the following detailed description and appended claims when taken with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The foregoing and other aspects and advantages of this invention are explained and described below with reference to the accompanying drawings, in which:
[0028] FIGS. 1A-1O illustrate the process steps employed in accordance with the method of this invention.
[0029] FIG. 2 shows the processing flow chart of the method of this invention in which a bilayer is formed in which a layer of silicon is deposited followed by a layer of germanium.
[0030] FIG. 3 shows the processing flow chart of the method of this invention in which a bilayer is formed in which a layer of silicon is deposited followed by a layer of silicon-germanium.
[0031] FIG. 4 shows the processing flow chart of the method of this invention in which a bilayer is formed in which a layer of silicon is deposited followed by a layer of silicon-germanium-carbon.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] A. Deposit Shallow Trench Isolation (STI) Dielectric in Shallow Trench in Semiconductor Substrate.
[0033] FIG. 1A is a schematic sectional view of a device 10 in an early stage of manufacture comprising a semiconductor substrate 11 with a top surface in which a shallow trench 13 T has been formed. The shallow trench 13 T is filled with a Shallow Trench Isolation (STI) dielectric 13 formed in accordance with step 31 in FIGS. 2-4 . The STI dielectric 13 separates the PFET regions on the left side of the semiconductor substrate 11 from the NFET regions on right side of semiconductor substrate 11 , as will be well understood by those skilled in the art.
[0034] The substrate 11 can comprise bulk Silicon (Si), Silicon on Insulator (SOI), bulk Germanium (Ge), Si/SiGe bilayers, or Si/SiGe on insulator. Also the device structure 10 could be modified to be in the form of 3D FETs such as FinFET devices, as will be well understood by those skilled in the art of FinFET devices.
[0035] As specified in step 32 in FIGS. 2-4 , the next step is to dope PFET and NFET regions in the substrate 11 one at a time.
[0036] B. Dope PFET Regions in the Semiconductor Substrate.
[0037] FIG. 1B shows the device 10 of FIG. 1A during performance of the first part of the step 32 in FIGS. 2-4 in which a first temporary photolithographic (preferably photoresist PR) mask 14 M was formed over the NFET region on the right side of the STI dielectric 13 in shallow trench 13 T in device 10 , while the PFET region on the left side of the STI dielectric 13 in shallow trench 13 T in device 10 was being doped with N− dopant ions 14 I thereby forming an N-SUB 14 to the left side of the STI trench 13 T. Preferably the N-SUB 14 comprises an N-well formed in the substrate 11 . Then the mask 14 M is stripped exposing the top surface of the NFET region.
[0038] C. Dope NFET Regions in the Semiconductor Substrate.
[0039] FIG. 1C shows device 10 of FIG. 1B during performance of the second part of step 32 ( FIGS. 2-4 ) in which a second temporary photolithographic (preferably photoresist PR) mask 15 M has been formed over the PFET region on the left side of the STI dielectric 13 in the shallow trench 13 T the device 10 , while the NFET region on the right side of device 10 is shown being doped with P− dopant ions 15 I thereby forming a P-SUB 15 to the right side of the shallow trench 13 T. Then the mask 15 M is stripped exposing the top surface of the P-SUB 15 in the PFET region.
[0040] In the doping provided in FIGS. 1B and 1C , a dopant level of from about 1e17 to about 1e18 atoms of dopant is preferred although not critical. Preferably highly localized halo doping is employed that goes up to about 1e19 atoms of dopant typically. As will be well understood by those skilled in the art a pad oxide layer which is conventionally employed is not shown for convenience of illustration and to make a more concise presentation of the invention.
[0041] D. Form Blanket Gate Dielectric Layer Over Substrate Including STI Dielectric.
[0042] FIG. 1D shows the device 10 of FIG. 1C after step 33 in FIGS. 2-4 in which a blanket, thin gate dielectric layer 12 has been formed covering the substrate 11 and the STI dielectric. The gate dielectric layer 12 , which is typically from about 0.8 nm to about 10 nm thick, is deposited preferably by a method such as thermal oxidation or chemical deposition. Preferably, the gate dielectric layer 12 is composed of a material selected from the group consisting of silicon oxide, silicon oxynitride, halfnium oxide, halfnium silicate, aluminum oxide, aluminum silicate, silicon nitride, zirconium oxide, zirconium silicate, tantalum oxide, tantalum silicate. Materials with similar characteristics can be employed.
[0043] E. Deposit a Blanket Thin Silicon Layer Composed of Amorphous Silicon or Polysilicon.
[0044] FIG. 1E shows the device 10 of FIG. 1D after step 34 in FIGS. 2-4 in which the first silicon thin film 16 of a thin bilayer 19 composed of silicon-germanium/silicon (SiGe/Si) which is shown in FIG. 1F has been formed. Alternatively, the thin film 18 may be composed of silicon-germanium-carbon/silicon (SiGeC/Si) as is also indicated in FIG. 1F . The lower, silicon thin film 16 , which was deposited on gate dielectric layer 12 , is preferably composed of amorphous silicon, but can be composed of polysilicon. If the first, silicon, thin film 16 comprises amorphous silicon (a-Si) film 16 , it preferably has a thickness typically from about 10 nm to about 20 nm which is deposited by a process such as Low Pressure Chemical Vapor Deposition (LPCVD) process or Atmospheric Pressure Chemical Vapor Deposition (APCVD) process. For deposition of an amorphous silicon (a-Si) thin film 16 , the process can begin with a typical precursor such as silane (SiH 4 ) or dichlorosilane (SiH 2 Cl 2 ). Preferably, the amorphous silicon (a-Si) thin film 16 is deposited by LPCVD at a temperature of between about 490° C. and 540° C., a pressure of between about 0.05 Torr and 50 Torr, and with a SiH 4 flow of between about 100 slm and 1500 slm.
[0045] FIG. 1F shows the device 10 of FIG. 1E after step 35 A in FIG. 2 , step 35 B in FIG. 3 , AND step 35 c in FIG. 4 .
[0046] F1. Deposit a Thin Film of Amorphous or Polycrystalline Germanium (Ge).
[0047] In accordance with FIG. 1F and FIG. 2 , an upper, silicon, thin film 18 of the thin bilayer 19 has been formed composed of an amorphous germanium (a-Ge) deposit or polycrystalline germanium (poly Ge) deposit. The Ge thin film 18 , which is preferably composed of an amorphous germanium (a-SiGe), has been deposited on the thin Si film 16 .
[0048] F2. Deposit a Thin Film of Amorphous Silicon-Germanium (a-SiGe) or Polycrystalline Silicon-Germanium (poly SiGe).
[0049] In accordance with FIG. 1F and FIG. 3 , an upper, silicon-germanium, second thin film 18 of the thin bilayer 19 has been formed composed of an amorphous silicon-germanium (a-SiGe) deposit or polycrystalline silicon-germanium (poly SiGe) deposit. The SiGe thin film 18 , which is preferably composed of an amorphous silicon-germanium (a-SiGe), has been deposited on the thin Si film 16 .
[0050] F3. Deposit a Thin Film of Amorphous Silicon-Germanium-Carbon (a-SiGeC) or Polycrystalline Silicon-Germanium-Carbon (poly SiGeC).
[0051] In accordance with FIG. 1F and FIG. 4 , the second, upper, silicon-germanium-carbon thin film 18 of the thin bilayer 19 has been formed composed of an amorphous silicon-germanium-carbon (a-SiGeC) or polycrystalline silicon-germanium (poly SiGe-carbon). The SiGeC thin film 18 , which is preferably composed of an amorphous silicon-germanium (a-SiGeC), has been deposited on the thin Si film 16 .
[0052] The Ge, SiGe or SiGeC upper thin film 18 , which has a thickness typically from about 10 nm to about 20 nm is deposited by with a Low Pressure Chemical Vapor Deposition (LPCVD) or Atmospheric Pressure Chemical Vapor Deposition (APCVD) process. Preferred precursors for the silicon and the germanium in the a-SiGe layer are silane (SiH 4 ) or dichlorosilane (SiH 2 Cl 2 ) for silicon, and germane (GeH 4 ) for germanium. A silane flow of between about 100 slm and 1500 slm is preferred or dichlorosilane flow of between about 100 slm and 1500 slm is preferred. The SiGe or SiGeC thin film 18 comprises an atomic percentage ratio of Si 1-X-Y Ge X C Y , where X=5 atomic % to 100 atomic % and Y=0+% to 5%. If the layer 29 contains carbon (as in SiGeC), the atomic percentage of carbon would be from a trace (0+%) to 5%, preferably, a trace (0+%) to 2%.
[0053] Techniques for depositing silicon-germanium alloys are well known in the art, for example as described in U.S. Pat. No. 5,336,903 entitled “Selective Deposition of Doped Silicon-Germanium Alloy on Semiconductor Substrate, and Resulting Structures”, which is incorporated by reference in its entirety. As stated above, the SiGe conductive film may be amorphous or polycrystalline. Deposition occurs by creating a gaseous environment comprising silane (SiH 4 ) and germane (GeH 4 ) in a ratio that precludes deposition on the exposed dielectric material. Other gaseous sources of silicon may be provided including dichlorosilane (SiH 2 Cl 2 ). The dielectric is typically SiO 2 , but in other embodiments, may be any other material that precludes nucleation of SiGe film when suitable ratios of germane and silane (or other sources of silicon) are used. The SiGe conductive film may be deposited using low pressure chemical vapor deposition (LPCVD) techniques familiar to those of skill in the art. It is expected that the selected deposition of the silicon germanium conductive film may be achieved at a temperature range of about 300 to 800 degrees C. In one embodiment, the ratio of germane to silane or dichlorosilane (SiH 2 Cl 2 ) is selected such that no deposition of the SiGe conductive film occurs on the dielectric layers. It is expected that ratios of germane to dichlorosilane in the amounts of about 0.025 to about 1.00 will produce suitable results. A pressure of about 2.5 Torr is suitable. In a preferred embodiment, a temperature of about 600° C. is used for the LPCVD process and a ratio of germane to dichlorosilane (SiH 2 Cl 2 ) of 0.20 is used. The process may also be adapted to use silane by one of skill in the art with minimal experimentation. Similar process parameter ranges are expected to produce suitable results when silane is used as the gaseous source for silicon. The precise ratio of silane to germane for selective deposition of SiGe conductive films may be empirically determined and is a function of the partial pressures of GeH 4 /SiH 4 , temperature, and total pressure.
[0054] G. Form A Mask on Top of PFET Region.
[0055] FIG. 1G shows the device 10 of FIG. 1F after step 36 in FIGS. 2-4 in which a photolithographic mask 20 (photoresist or the like) has been formed over the N-Sub 14 (i.e. the PFET region on the left) in the device 10 , leaving the NFET region (on the right) of the device 10 exposed. The method of formation of such a photolithographic mask will be well understood by those skilled in the art. Alternatively, a thin layer of silicon oxide or silicon nitride can be deposited or thermally grown on top of Si/SiGe layer followed by the photolithographic step. In this case, the dielectric layer (silicon oxide or silicon nitride) is then patterned by an etch step before proceeding to the next step.
[0056] H. Selectively Etch Away Exposed Portions of the a-SiGe or Poly Si—Ge Layer Over NFET Regions.
[0057] FIG. 1H shows the device 10 of FIG. 1G after the exposed portion of the SiGe or SiGeC thin film 18 was removed by selective etching (step 37 A in FIG. 2 and step 37 B in FIG. 3 ) in the NFET region exposing the surface of the silicon thin film 16 above the P-Sub 15 (in the NFET region), while leaving the underlying silicon thin film 16 above the gate dielectric over P-Sub 15 . One etchant that can be used in steps 37 A/ 37 B is an aqueous solution of NH 4 OH:H 2 O 2 :H 2 O at a temperature of about 65° C. Other etchants that are selective to Si can be used as will be well understood by those skilled in the art.
[0058] I. Strip Mask From PFET Region and Anneal to Diffuse Ge into a-Si or Si Layer in the PFET Region
[0059] Yielding Poly Si—Ge or Poly Si—Ge—C Bilayer in the PFET Region.
[0060] FIG. 11 shows the device 10 of FIG. 1H after stripping the mask 20 (step 38 in FIGS. 2-4 , optionally including the optional silicon oxide or silicon nitride mask) and then subjection of device 10 to the high temperature annealing for the purpose of interdiffusing some of the Ge atoms from the upper thin film 18 downward into the Si thin film 16 above the N-Sub in the PFET region, converting Si thin film 16 into a polysilicon-Ge thin film 16 A. The portion of the Si lower thin film 16 above the P-sub 15 , remains a polysilicon, thin film 16 B, as before the annealing step. In other words, in the PFET region, the concentrated Ge atoms in the upper SiGe/SiGeC thin film 18 are partially diffused down into the lower layer, but many of the Ge atoms remain in the upper SiGeC thin film 18 so that both layers have close to the same concentration of Ge. The performance of a high temperature annealing process of step 39 A in FIG. 2 and step 39 B in FIG. 3 , which is preferably performed within a temperature range from a minimum of about 800° C. to a maximum of about 1200° C. Preferably the maximum is about 1100° C. During the high temperature annealing process, the amorphous silicon in layers 16 and 18 is converted to polysilicon. Upon annealing if the material contains amorphous silicon, it is converted into polysilicon.
[0061] J. Etching to Remove Native Oxide.
[0062] FIG. 1J shows the device 10 of FIG. 11 during removal of a native oxide layer (step 40 in FIGS. 2-4 ) which may have formed during annealing was removed by dipping the device into a aqueous hydrofluoric acid solution. The silicon oxide or silicon nitride mask, if not removed in the previous step, can be removed at this step as well.
[0063] K. Deposit Blanket Layer of Gate Electrode Polysilicon.
[0064] FIG. 1K shows the device 10 of FIG. 1J and after a blanket layer 20 of polysilicon Si was deposited over both the NFET and PFET regions (step 41 in FIGS. 2-4 ).
[0065] Referring to FIGS. 1L and 1M , in accordance with the usual practice, a masking step is used for pre-doping of the NFET and PFET gates separately.
[0066] L. Form Mask Over NFET Region and Dope Gate Electrode Layers Over PFET Region.
[0067] Referring to FIG. 1L , the device 10 of FIG. 1K is shown after doping of the NFET gate electrode layers 16 A/ 18 A/ 20 A (in accordance with a portion of step 42 in FIGS. 2-4 ). FIG. 1L shows a mask 27 P formed covering the NFET region and leaving the PFET region exposed. Then the layers 16 A of polysilicon, SiGe thin film 18 A and layer 20 A (the left region of layer 20 in the PFET region) to be used to form the gate for PFETs can be doped by implanting either boron ions 21 P or boron difluoride (BF 2 ) therein. Preferably, the dopant 21 P (boron) is implanted by ion implantation at a energy level of from about 1 keV to about 30 keV with a dose of 1e15 cm −2 to 9 e15 cm −2 yielding a concentration of from about 1e20 cm −3 to about 1e21 cm −3 . The dopant 21 P is implanted down into the layers of polysilicon 16 A/ 20 A and the poly-Ge thin film 18 A.
[0068] M. Form Mask Over PFET Region and Dope Gate Electrode Layers Over NFET Region.
[0069] Referring to FIG. 1M , the device 10 of FIG. 1L after doping of the PFET gate electrode layers 16 B/ 20 B (in accordance with a portion of step 42 in FIGS. 2-4 ). FIG. 1M shows a mask 27 N formed covering the PFET region and leaving the NFET region exposed so that the layer 20 of polysilicon to be used to form the gates for NFETs can be doped by implanting either phosphorus (P) or arsenic (As) ions 21 N therein. Preferably, the dopant 21 N employed comprises ions 21 N (phosphorus (P) or arsenic (As)) which are implanted by ion implantation at a energy level of from about 1 keV to about 30 keV with a dose of 1e15 cm −2 to 9e15 cm −2 yielding a concentration of from about 1e20 cm −3 to about 1e21 cm −3 . The dopant 21 P is implanted down into the layers of polysilicon 16 B/ 20 B.
[0070] N. Form Gate Electrode Masks on Polysilicon Layers and Etch Unprotected Areas Down to Substrate.
[0071] FIG. 1N shows device 10 of FIG. 1M after gate electrode, photolithographic, patterning masks 26 P/ 26 N preferably composed of patterned photoresist (PR), have been formed over the over the polysilicon layers 20 A/ 20 B. The mask 26 P is formed over layer 20 A in the PFET region and the mask 26 N is formed over layer 20 B in the NFET region. Then an etching step is performed (in accordance with the remainder of step 42 in FIGS. 2-4 ) in which the gate electrode stacks 23 P (above the PFET region) and 23 N (above the NFET region) have been formed over the N-Sub 14 and the P-Sub 15 respectively by anisotropically etching away the unprotected portions of those layers down to the substrate 11 aside from the masks 26 P and 26 N respectively.
[0072] O. Form LDSs/LDDs; Spacers; & Source/Drain Regions.
[0073] FIG. 1O shows the device 10 of FIG. 1N after an additional PFET Lightly Doped Drain (LDD) doping mask (not shown) and an additional NFET Lightly Doped Source (LDS) doping mask (not shown) were formed in the usual sequence. Using those masks in the usual sequence, the extensions, i.e. the usual Lightly Doped Drain (LDD) P− regions and N− regions and Lightly Doped Source (LDS) P− regions were formed. The extensions include N− regions in the top surface of substrate 11 juxtaposed with the gate electrode stacks 23 P and P− regions in the top surface of substrate 11 juxtaposed with the gate electrode stacks 23 N, as will be well understood by those skilled in the art (in accordance with a portion of step 43 in FIGS. 2-4 ).
[0074] Next spacers 24 were formed on the sidewalls of the gate electrode stacks 23 P and 23 N in accordance with conventional process, as indicated in a portion of step 43 in FIGS. 2-4 .
[0075] Then P+ doped source/drain a mask (not shown) was formed over the NFET region covering the stack 23 N, the exposed surface of the P-Sub 15 and a portion of the STI region 13 T. Then the P+ doped Source/Drain regions 25 P were formed in the surface of the N-Sub 14 self-aligned with the spacers of the stack 23 P.
[0076] Finally, an N+ doped source/drain a mask (not shown) was formed over the PFET region covering the stack 23 P, the exposed surface of the N-Sub 14 and a portion of the STI region 13 T. Then the N+ doped source/drain regions 25 N were formed in the surface of the P-Sub 15 self-aligned with the spacers of the stack 23 N completing step 43 in FIGS. 2-4 .
[0077] The process shown in FIGS. 2-4 ends at step 44 . Other conventional processing continues as will be well understood by those skilled in the art.
[0078] While this invention has been described in terms of the above specific embodiment(s), those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the appended claims, i.e. that changes can be made in form and detail, without departing from the spirit and scope of the invention. Accordingly all such changes come within the purview of the present invention and the invention encompasses the subject matter of the following claims. | Form a dielectric layer on a semiconductor substrate. Deposit an amorphous Si film or a poly-Si film on the dielectric layer. Then deposit a SiGe amorphous-Ge or polysilicon-Ge thin film theteover. Pattern and etch the SiGe film using a selective etch leaving the SiGe thin film intact in a PFET region and removing the SiGe film exposing the top surface of the Si film in an NFET region. Anneal to drive Ge into the Si film in the PFET region. Deposit a gate electrode layer covering the SiGe film in the PFET region and cover the exposed portion of the Si film in the NFET region. Pattern and etch the gate electrode layer to form gates. Form FET devices with sidewall spacers and source regions and drains regions in the substrate aligned with the gates. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for manufacturing an orifice plate having the through holes arranged on a plate material, which become orifices for discharging liquid droplets. Also, the invention relates to a method for manufacturing a liquid discharge head provided with an orifice plate through which desired liquid is discharged by the creation of bubbles by the application of thermal energy or the like.
2. Related Background Art
There has been known conventionally the so-called bubble jet recording method, which is an ink jet recording method whereby to provide ink with thermal energy or the like to change the states of ink with the abrupt voluminal changes (creation of bubbles) of ink to follow, and then, to discharge ink from the discharge ports by the active force based upon this change of states, thus allowing ink to adhere to the surface of a recording medium for the formation of images. As disclosed in the specifications of Japanese Patent Publication Nos. 61-059911 and 61-059914, and others, the recording apparatus that adopts the bubble jet recording method is generally provided with discharge ports through which ink is discharged; the ink flow paths communicated with the discharge ports; and heat generating elements (electrothermal transducing devices) arranged in the ink flow paths as energy generating means for discharging ink.
In accordance with a recording method of the kind, it is possible to record high quality images at higher speeds with a lesser amount of noises. At the same time, the discharge ports of the head that uses this recording method can be arranged in higher density to discharge fine ink droplets, hence making it possible to record images in a high resolution with the apparatus that can be made smaller accordingly. Color images can also be obtained easily, among many other excellent features. As a result, the bubble jet recording method has been widely utilized in recent years for a printer, a copying machine, a facsimile equipment, and other office equipment. Further, it has been used for the textile printing system or other industrial ones.
Along with the wider application of bubble jet technologies and techniques as described above, it has been strongly demanded to develop a recording apparatus of a higher resolution at lower costs.
Now, in conjunction with FIGS. 8A to 8 D, the description will be made of the conventionally proposed method for manufacturing a liquid discharge head provided with an orifice plate having orifices formed on it (which is disclosed in the specification of Japanese Patent Laid-Open Application No. 02-188255).
(A) The resist 102 is formed on the conductive substrate 101 (SUS substrate, for example) by the utilization of the photolithographic techniques.
(B) After that, by means of electroforming, the metallic layer 103 (nickel, for example) is formed on the conductive substrate 101 .
(C) The water repellent layer 105 are formed on the resist 102 , and the metallic layer 103 produced by means of electroforming.
(D) At the same time that the resist 102 is removed from the conductive substrate 101 , the water repellent layer on the orifice unit is removed by peeling off the orifice plate 109 from the conductive substrate 101 .
(E) The orifice plate is adhesively bonded to the elemental substrate 106 that includes the energy generating elements 107 and the flow paths 113 produced in advance, hence completing a part of the liquid discharge head (FIGS. 8A to 8 D).
Now, another conventional techniques will be described in conjunction with FIGS. 10A to 10 D.
(A) The resist 102 is formed on the conductive substrate 101 (SUS substrate, for example) by the utilization of the photolithographic techniques.
(B) After that, by means of electroforming, the metallic layer 103 (nickel, for example) is formed on the conductive substrate 101 .
(C) At the same time that the resist 102 is removed from the conductive substrate 101 , the orifice plate 109 is peeled off from the conductive substrate 101 .
(D) After that, the water repellent agent 105 is transferred to complete the orifice plate 109 .
(E) The orifice plate is adhesively bonded to the elemental substrate 106 that includes the energy generating elements 107 and the flow paths 113 produced in advance, hence completing a part of the liquid discharge head (FIGS. 10A to 10 D).
However, there are following problems encountered in the method for manufacturing the liquid discharge head provided with the orifice plate having the orifices as described above if it is intended to obtain a liquid discharge head of a higher performance.
In accordance with the conventional method shown in FIGS. 8A to 8 D, when the orifice plate 109 is peeled off, the resist 102 is removed, and also, the water repellent agent 105 on the orifice unit is removed at the same time. Therefore, as shown in FIG. 8D, the water repellent agent 105 presents an abnormal configuration on the surface of the orifice plate unit on the opening side. As a result, the stabilized sectional area of the orifice opening unit cannot be provided. Thus, the sectional area of the orifice opening unit is not formed invariably to make it impossible to obtain prints in a higher quality. Also, since the orifice unit is in an abnormal configuration, the directional accuracy of the ink droplets 110 cannot be kept invariably as shown in FIG. 9 . As a result, the printing operation is affected so as to produce the twisted discharges or uneven prints eventually.
Also, in accordance with the conventional method of manufacture shown in FIGS. 10A to 10 D, when the orifice plate is formed on the conductive substrate 101 by means of electroforming, the metallic layer 103 gets into the resist 102 . Then, as shown in FIG. 10D, the circumference of each orifice of the orifice plate on the surface side is formed in the R-letter form. Even if it is intended to transfer the water repellent agent 105 to the orifice plate thus formed, the water repellent agent 105 is not transferred to the R-letter formed portions. As a result, as shown in FIG. 11, ink is caused to reside on each of the R-letter portions of the metallic layer, and it may take a long time to refill ink for the one thus residing, which causes the frequency response to be degraded.
SUMMARY OF THE INVENTION
The present invention is designed in consideration of these problems as discussed above. It is an object of the invention to provide a recording apparatus whereby to implement recording in higher resolution at higher frequency, and to record images in higher quality without twisted prints and the unevenness of the recorded images as well.
In order to achieve such objective, the method of the present invention for manufacturing an orifice plate is to manufacture the orifice plate provided with a plate material having a through hole arranged to become an orifice for discharging liquid, and comprises the following steps of:
a. arranging a resin layer in a position corresponding to the through hole on the surface of a conductive substrate in a configuration corresponding to the through hole in a thickness corresponding at least to the length of the through hole;
b. forming a metallic layer by means of electro-forming on the exposed surface of a portion of the conductive substrate corresponding to the plate material in a thickness corresponding to the thickness of the plate material in order to obtain the metallic layer in a state where the resin layer is filled in the through hole portion;
c. applying water repellent resin to the surface of the metallic layer having the resin layer filled therein;
d. peeling off the metallic layer from the conductive substrate together with the resin layer to obtain the plate material in a state where the through hole portion is filled with the resin layer; and
e. removing by the laser irradiation the resin layer portion of the plate material in a state where the resin layer is filled in the through hole portion having the water repellent layer coated on the surface in order to form the through hole.
Also, still another method of the present invention for manufacturing an orifice plate is to manufacture the orifice plate provided with a plate material having through holes arranged to become orifices for discharging liquid, and comprises the following steps of:
a. arranging a first resin layer in a position corresponding to the through hole on the surface of a conductive substrate in a configuration corresponding to the through hole in a thickness corresponding at least to the length of the through hole;
b. forming a metallic layer by means of electroforming on the exposed surface of a portion of the conductive substrate corresponding to the plate material in a thickness corresponding to the thickness of the plate material in order to obtain the metallic layer in a state where a first resin layer is filled in the through hole portion;
c. coating water repellent resin on the surface of the metallic layer having the first resin layer filled therein;
d. covering a second resin layer on the surface of the metallic layer having the water repellent resin coated thereon with the exception of the portion corresponding to the through hole opening portion;
e. removing the water repellent resin on the portion corresponding to the through hole opening portion by means of etching through the second resin layer;
f. peeling off the plate material from the conductive substrate together with the first and second resins; and
g. processing to open a through hole by removing the first resin and the second resin from the plate material provided with the water repellent resin on the aforesaid surface.
Also, the method of the present invention for manufacturing a liquid discharge head comprises the step of arranging orifices for discharging liquid droplets on the leading end of the liquid paths by installing the orifice plate on the discharge head member provided with the liquid paths, and the discharge energy generating elements to generate energy for discharging liquid in the liquid paths as liquid droplets. With this method, the orifice plate is formed by either one of the methods of the present invention for manufacturing an orifice plate as referred to in the preceding paragraphs.
In accordance with the method of the present invention, the orifices of the orifice plate are formed by removing the resin layer with the laser irradiation or with the elution using the remover. As a result, the variation of the sectional areas of the orifice opening portion is made smaller to prevent the orifices from being in an abnormal configuration. Hence, it becomes possible for the liquid discharge head using the orifice plate thus obtained by means of the method of the present invention to obtain the recorded images in higher quality. Also, with the water repellent layer formed on the orifice opening portion entirely, the refilling of ink is made faster to make it possible to print at higher frequency.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A, 1 B, 1 C, 1 D and 1 E are plan views and cross-sectional views which schematically illustrate a first invention (a first embodiment).
FIGS. 2A, 2 B, 2 C, 2 D and 2 E are plan views and cross-sectional views which schematically illustrate a second invention (a second embodiment).
FIG. 3 is a cross-sectional view which shows a liquid jet discharge head schematically in accordance with a third invention (both the first and second embodiment).
FIG. 4 is a perspective view which schematically illustrates the liquid discharge head in accordance with the third invention.
FIG. 5 is a view which illustrates the head cartridge in accordance with the third invention.
FIG. 6 is a view which shows one example of the liquid jet apparatus in accordance with the third invention.
FIG. 7 is a view which illustrates the full line head in accordance with the third invention.
FIGS. 8A, 8 B, 8 C and 8 D are cross-sectional views and plan views which schematically illustrate the conventional method for manufacturing an orifice plate.
FIG. 9 is a cross-sectional view which illustrates the conventional liquid discharge head schematically.
FIGS. 10A, 10 B, 10 C and 10 D are cross-sectional views and plan views which schematically illustrate another conventional method for manufacturing an orifice plate.
FIG. 11 is a cross-sectional view which illustrates another conventional liquid discharge head schematically.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, with reference to the accompanying drawings, the embodiments will be described in accordance with the present invention.
The method for manufacturing an orifice plate embodying the present invention utilizes the photosensitive resin to form the resin layer 102 on the conductive substrate 101 as shown in FIG. 1 A. After that, the metallic layer 103 is formed by means of electroforming as shown in FIG. 1 B. Nickel is used for the metallic layer thus formed. It may be possible to use the nickel alloy having cobalt or palladium mixed. Then, as shown in FIG. 10C, after the metallic layer 103 has been formed, the water repellent layer 105 is coated on the metallic layer 103 and the resin layer 102 by the application of spinner, splay, rolling coater, or the like. In this manner, the step between the metallic layer 103 and the resin layer 102 can be buried by means of the water repellent layer 105 . At the same time, the surface can be made smooth. Also, in this case, it may be possible to form the contact enhancement layer between the metallic layer 103 and the water repellent layer 105 . For the method for forming the contact enhancement layer, it may be possible to apply a sealant, A1110 (product name: manufactured by Nippon Unika K.K.).
Then, as shown in FIG. 1D, the metallic layer 103 is peeled off from the conductive substrate 101 . The metallic layer is the plate member having the through hole portion which provides orifices, but in a state of being filled with the resin layer 102 . After that, excimer layer is irradiated over the entire face of the plate member from the reverse side of the face of the plate member where the water repellent layer 105 has been formed. At this juncture the metallic layer 103 is not removed by the irradiation of the excimer laser, but only the resin layer 102 is completely removed. Thus, orifices 104 are formed. In this manner, the orifice plate 109 , which is provided with the tapered orifices 104 , is completed as shown in FIG. 1 E.
For the conductive substrate prepared by the method as described above, it is possible to form the metallic layer by means of electroforming, and use preferably the plate substrate formed with the material, such as stainless steel, iron, nickel, copper, brass, or aluminum if only the material used can be peeled off after the formation of the metallic layer. Of these materials, the stainless steel is more preferable because it has corrosion resistance. Of the stainless steel, SUS-304 and SUS-316 are particularly preferable. As the peeling method applicable to the conductive substrate, there is, among some others, the one whereby to apply the ultrasonic waves while the substrate is immersed in the remover or the one whereby to apply the inverted bias of the one applied at the time of electroforming, while the substrate is immersed in the liquid which is used for electroforming the metallic layer. Here, the step in which the conductive substrate is peeled off is carried out after the step in which the water repellent layer is formed so that the formation of the water repellent layer is facilitated. However, if the metallic layer is sufficiently thick, it may be possible to form the water repellent layer in the same liquid after having peeled off the substrate by the application of the inverted bias following the execution of the electroforming.
Also, as the photosensitive resin, it is preferable to use the one which does not present any changes in the configuration after the formation of the metallic layer by means of the electroforming, but it is still possible to secure the desired orifice configuration, and also, to enable the drilling work to be performed effectively by the laser processing. For example, the dry film or resist for plating use, such as manufactured by Tokyo Oka K.K., may be utilized. With the fine process requirement, and the corrosion-resistance in view, it is preferable to use the dry film, SY-325 or the resist, PMER (both product names: manufactured by Tokyo Oka K.K.). Of these products, the PMER is particularly preferable. In this respect, it is possible to use either the positive type or the negative type photosensitive resin. However, it is desirable to use the positive type photosensitive resin for the enhancement of the removal performance upon removing the resin layer 102 entirely.
The layer thickness of the resin layer should be that of the metallic layer corresponding at least to the thickness of the orifice plate. If, for example, the thickness of the orifice plate is 20 μm, the resin layer should be thicker than the thickness of the orifice plate. Then, it is preferable to make the thickness of the resin layer is approximately 25 μm.
As to the water repellent agent, any one of agents is usable if only it can achieve the purpose of its use. For example, fluororesin is usable. In this respect, it is particularly preferable to use Cytop (product name: manufactured by Asahi Glass K.K.) from the viewpoint of its water-repellency. The amount of its adhesion or the layer thickness may be determined so as to obtain the intended effect. Also, the water repellent agent is coated on the metallic layer, hence making it possible to smooth the surface thereof.
Although depending on the material of resin layer and the layer thickness, the condition of laser beam irradiation is, in general, the oscillation energy=0.5 to 2 J/cm 2 ·pulse, frequency=10 to 300 Hz, the pulse number=100 to 500 pulses. Further, in consideration of the hole configuration and thermal influence, it is preferable to set the oscillation energy at 0.8 to 1.2 J/cm 2 ·pulse, and in consideration of the performance on the large-scale production, it is preferable to set the frequency at 150 to 250 Hz. If the orifice plate thickness is 20 μm, it is preferable to set the pulse number at 150 to 200 pulses for the reasons that holes should be open completely. Here, the excimer laser can be utilized as the laser, for example.
As shown in FIGS. 2A to 2 C, another method for manufacturing the orifice plate in accordance with the present invention is the same as the method of the first invention in the steps in which the conductive substrate 101 is prepared, and the resin layer 102 is formed, and the metallic layer 103 is formed by means of electroforming, and then, the water repellent layer 105 is coated. After that, as shown in FIG. 2D, a second resin layer 114 is formed on the water repellent layer, and by the utilization thereof, the water repellent layer is etched on the orifices.
Subsequently, when the orifice plate 109 is peeled off from the conductive substrate 101 , the resin layer releasing liquid is used. Then, as shown in FIG. 2E, the orifices 104 are formed by peeling off the first resin layer and the second resin layer at the same time. Hence, the orifice plate 109 is completed.
As the second resin layer, any one of layers is usable if only it has the properties for use of removal from the water repellent agent on the upper portion of the orifices so as to be capable of performing the removal of the resin layer effectively from the water repellent layer arranged on the surface of the metallic layer. For example, there may be used the positive type resist OFPR-800 (product name: manufactured by Tokyo Oka, K.K.) or the like.
To remove the water repellent layer on the orifice portion, it is preferable to use the activated gas for etching use produced by the combination of carbon tetrafluoride and oxygen, irrespective of the dry etching, wet etching, or the like which is equally applicable.
Now, in conjunction with FIG. 4, the description will be made of the step in which the orifice plate 109 is adhesively bonded to the elemental substrate having the discharge ports formed on it in accordance with the method for manufacturing a liquid discharge head in accordance with the present invention. Here, the orifice plate is completed by means of any one of the methods for manufacturing an orifice plate in accordance with the present invention.
The bonding agent is applied to the orifice plate side, and the member (orifice plate 109 ) having the orifices formed is bonded to the face portion of the liquid discharge head having the flow paths 112 , the elemental substrate 106 , and the ceiling plate 108 . At this juncture, it may be possible to coat the bonding agent on the face side or transfer it to that side. Also, the epoxy bonding agent is typically used as the bonding agent, but it may be possible to use the one having the thermal plastic property or silicone or hot-melt type. After the orifice plate is adhesively bonded, it is assembled in the ink cartridge 17 to complete the liquid discharge head as shown in FIG. 4 .
FIG. 5 is a view which shows the head cartridge 17 having the ink container for holding liquid to be supplied to the liquid discharge head of the present invention. Here, it is possible to refill ink in the ink container after ink has been consumed.
FIG. 6 is a view which schematically shows the structure of the liquid jet apparatus having the aforesaid liquid discharge head mounted thereon. On the carriage HC of the liquid jet apparatus of the present embodiment, there is mounted the head cartridge having the liquid tank unit 70 and the liquid discharge head unit 60 detachably installed on it. The carriage can reciprocate as indicated by arrows a and b in the width direction of a recording medium 80 carried by recording medium carrying means.
Also, the liquid jet apparatus of the present embodiment is provided with the motor 81 serving as the driving source to drive the recording medium carrying means and the carriage HC, and also, with the gears 82 and 83 to transmit the driving power of the driving source to the carriage HC, and the carriage shaft 85 , among some others. With this recording apparatus and the liquid discharge method adopted for this recording apparatus, it becomes possible to obtain the objective images in good condition by discharging liquid to various kinds of recording media.
FIG. 7 is a view which schematically shows the socalled full line head having a plurality of discharge ports arranged over the recordable area of a recording medium 80 , and the apparatus as well, in accordance with the present invention. In FIG. 7, a reference numeral 61 designates the full line head which is arranged in the position shiftable to the recording medium 80 . A reference numeral 90 designates the carrier drum which serves as recording medium carrying means.
So far, the present embodiment has been described. Here, however, it is needless to mention that each of the liquid discharge heads and liquid jet apparatuses of the present invention corresponds to each of the ink discharge methods, ink discharge recording heads, ink jet recording apparatuses that uses the recording ink as the liquid which is discharged.
(First Embodiment)
For the present embodiment, the method which is illustrated in conjunction with FIGS. 1A to 1 E is the example in which the orifice plate is formed.
At first, the resin layer 102 is formed on the conductive substrate 101 (SUS substrate) by the utilization of the photosensitive resin. In this respect, the positive type resist (product name: PMER) manufactured by Tokyo Oka K.K. is used for the photosensitive layer formed in a thickness of 16 μm. After that, the metallic layer 103 is formed by means of electroforming in a thickness of 17 μm. After the metallic layer 103 is formed, the water repellent resin is coated by means of the splay method on the metallic layer 103 and the resist layer 102 to form the water repellent layer 105 . The water repellent resin used then is the Cytop (product name: manufactured by The Asahi Glass K.K.) and coated under the condition given below using the splay coating machine manufactured by the Nordson Inc. (a microspraying apparatus):
Pressure: 1.5 kg/cm 2
Feeding rate: 15 mm/sec.
Feed amount: 10 mm
With the coating of the water repellent agent under this condition, the water repellent layer 105 is formed in a thickness of 0.1 to 0.3 μm.
After that, the conductive substrate 101 and the metallic layer 103 are again immersed in the liquid used for the application of the electroforming. Then, the inverted bias of the one applied at the time of electroforming is applied in the liquid to peel off the orifice plate 109 from the conductive substrate 101 (SUS substrate). Subsequently, the entire face of the orifice plate is irradiated by excimer laser to remove the resin layer 102 . Thus, the orifices 104 are formed. Here, the condition of the laser processing then is:
Oscillation energy=1 J/cm 2 ·pulse
Frequency=200 Hz
Pulse number=200 pulses
Then, after the orifices are laser processed, the orifice plate is completed as shown in FIG. 1 E.
Now, in conjunction with FIG. 4, the description will be made of the bonding process in which the orifice plate 109 is adhesively bonded to the elemental substrate having the flow paths formed on it.
By use of the transfer method, the epoxy bonding agent is coated on the orifice plate side. Then, the member (orifice plate 109 ) having orifices are formed is bonded to the face of the liquid discharge head provided with the flow paths 112 , the elemental substrate 106 , and the ceiling plate 108 , and then, assembled into the ink cartridge 17 to complete the liquid discharge head is completed as shown in FIG. 4 .
FIG. 3 shows the discharging state of the head thus completed. The orifice unit is stably formed in a specific configuration. The water repellent layer is formed around orifices uniformly. As a result, there is no print twisting, and high quality images are obtainable. Also, ink is not allowed to spread over the face of the orifice unit to speed up the ink refilling, hence making it possible to print with a quicker responses.
(Second Embodiment)
The present embodiment relates to the example in which an orifice plate is formed in accordance with a method shown in FIGS. 2A to 2 D.
At first, the conductive substrate 101 is prepared. The resin layer 102 is formed, and the metallic layer 103 is also formed by means of electroforming. Then, the water repellent layer 105 is formed as in the first embodiment.
After that, a second resin layer 114 is formed on the water repellent layer with the patterning which utilizes the photolithographic process. Then, with the second resin layer which is used as the mask, the water repellent layer is etched to remove the water repellent layer on the orifices. The second resin used at that time is the positive type resist OFPR-800 (product name: manufactured by Tokyo Oka K.K.). The thickness of the second resin layer is 2 μm. Also, at this juncture, the etching is performed by the dry etching method in a condition of power=500 W under a pressure of 10 pascal in a gas flow rate (carbon tetrafluoride=50 SCCM and oxygen=10 SCCM).
Then, a specific resin layer releasing agent is used when the orifice plate 109 is peeled off from the conductive substrate 101 (SUS substrate). The first resin layer and the second resin layer are peeled off at the same time to form the orifices 104 . Thus, the orifice plate 109 is completed.
Subsequently, the orifice plate 109 thus completed is adhesively bonded to the elemental substrate having the discharge ports formed on it, and then, assembled into the ink cartridge 17 . The steps in which to complete the liquid discharge head as shown in FIG. 4 are the same as those in the first embodiment.
The discharge condition of the head thus completed is substantially the same as the first embodiment (as shown in FIG. 3 ), and other configurations and performances are also substantially the same as those of the first embodiment.
The orifice plate of the present invention, which is obtainable by either one of the methods of manufacture described above, has the orifice unit formed stably in a specific configuration, and the water repellent agent is applied to the circumference of the orifices uniformly. Likewise, the method of the present invention for manufacturing a liquid discharge head using either one of these orifice plates provides the liquid discharge head which is capable of printing without any print twisting caused by the unstable configuration of the orifice unit, hence making it possible to obtain images in higher quality. Also, the water repellent agent (area) is formed uniformly around the orifices to prevent the ink face from spreading widely. As a result, the ink refilling becomes quicker to make printing possible with quicker responses accordingly. | A method for manufacturing an orifice plate with a plate material having a through hole arranged to become an orifice for discharging liquid comprises the steps of arranging a resin layer in a position corresponding to the through hole on the surface of a conductive substrate in a configuration corresponding to the through hole in a thickness corresponding at least to the lenght of the through hole, forming a metallic layer by means of electro-forming on the exposed surface of a portion of the conductive substrated corresponding to the plate material in a thickness corresponding to the thickness of the plate material in order to obtain the metallic layer in a state where the resin layer is filled in the through hole portion, applying water repellent resin to the surface of the metallic layer having the resin layer filled therein, peeling off the metallic layer from the conductive substrate together with the resin layer to obtain the plate material in a state where the through hole portion is filled with the resin layer, and removing by laser irradiation the resin layer portion of the plate material in a state where the resin layer is filled in the through hole portion having the water repellent layer coated on the surface in order to form the through hole. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to a rotation switching device of a double-function sewing machine, which serves for switching by rotation a machine body of the sewing machine, which is incorporated with two different stitch forming mechanisms, to an operative position of the particular stitching function of either of the mechanisms.
The double-function sewing machine is disposed with needle dropping positions of a lock stitch and an overlock stitch at a right and a left, or a front and a rear in order not to interfere with the stitching operation of each other.
When the lock stitch is switched to the overlock stitch or vice versa, the operator lifts up the sewing machine which is heavy in weight from a machine positioning and mounting surface and rotates it horizontally, for working convenience. Since this work is troublesome due to carrying of the heavy load, it has been desired to solve these problems.
SUMMARY OF THE INVENTION
Therefore, it is an object of the invention to slightly lift a machine body from the said positioning surface by external and light operation, rotate it horizontally, and move it down by reverse operation and position it on the mounting surface by means of support feet in order to properly position the desired stitch forming mechanism.
These and other objects of the invention are attained by a double-function sewing machine comprising a machine body, a lock stitching mechanism and an overlock stitching mechanism positioned at two opposite sides of the machine body, and feet positioned on a lower surface of the machine body and abutting against a machine mounting surface on which the machine is positioned. A switching device is incorporated for switching the positions of the lock stitching mechanism and the overlock stitching mechanism, which includes rotating switching means disposed on the lower surface of the machine body and including a rotatable operating member, a base disc operatively connected to the operating member and adapted to move in a vertical direction with respect to said lower surface upon rotation of the operating member between a rest position in which said base disc is above the machine mounting surface and an operating position in which the base disc projects downward farther than the feet to contact said machine mounting surface, whereby the machine body is lifted from the machine mounting surface and may be rotated in a horizontal plane to place a required one of the stitching mechanisms to a use position.
The present invention will be explained in reference to the attached drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view showing a double-function sewing machine incorporating the device of the invention;
FIG. 2 is a view seen from arrow A in FIG. 1;
FIG. 3 is an exploded view of the device according to the invention;
FIG. 4 is a view seen from arrow B in FIG. 3;
FIG. 5 is a perspective view showing a rest position and an operating position of the operating member in relation with the sewing machine;
FIG. 6 is a view showing relation between the instant device, the sewing machine and the machine mounting surface in the rest position of the operating member;
FIG. 7 is a view showing relation between the device, the sewing machine and the machine mounting surface in the operating position of the operating member;
FIG. 8 is a vertical cross-sectional view showing relation between a cam lift plate and the operating member of the present device;
FIG. 9 is a vertical cross-sectional view of a main part of the present device, showing the operating member in the rest position;
FIG. 10 is a partial vertical cross-sectional view of the main part of the device along a center line of a cam groove, showing the operating member in the rest position;
FIG. 11 is a vertical cross-sectional view showing a tubular base member in relation with the operating member;
FIG. 12 is a vertical cross-sectional view of the main part of the device, showing the operating member in the operating position;
FIG. 13 is a vertical cross-sectional view of the main part of the device along the center line of the cam groove, showing the operating member in the operating position; and
FIG. 14 is a schematic plan view explaining a horizontal switching rotation of the machine body.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The attached drawings illustrate an embodiment of the invention. In FIG. 1, the reference numeral 1 is a machine body of a double-function sewing machine 2, the numeral 3 is a stitching part of the lock stitch forming mechanism (called as "lock stitch mechanism"), and 4 is an overlock stitch forming mechanism (called an "overlock stitch mechanism"). These stitch mechanisms are alternatively selected and driven by switching a dial 5.
Referring to FIG. 2, there are, under the lower part of the machine body 1, a pair of base tubular members 6 and 7 at the front and rear sides thereof, which are provided with support feet 8, 9, 10 and 11, comprising an elastic material at lower parts thereof.
On the lower part of the machine body 1, a rotation switching device 12 is disposed. The device 12 will be explained with respect to the main parts thereof in reference to FIG. 3. A base disc 13 is defined with a ring groove 13a and is implanted at its center with a pin 14 having a groove 14a at an upper portion. A sheet disc 16 is attached under the ring groove 13a, and this sheet comprises a substance having a large friction coefficient with the positioning-mounting surface 15 of the sewing machine.
An operating member 17 has an extended operating portion 17a, whose bent portion 17b is attached with an element 18; member 17 is formed at its center with a hole 17c for passing the pin 14 of the base disc 13 therethrough and is formed with a plurality of holes 17d for holding a plurality of balls 19 (four balls in this instance) together with the groove 13a of the base disc 13, and is implanted with a pair of pins 17e having grooves 17f at their upper parts.
A reference will be made to a cam lift plate 20 in FIG. 4. The cam lift plate 20 is formed with a passing hole 20b at the center of a projection 20a, cam grooves 20c of the member corresponding to the number of the balls 19 engaging grooves 20d of the same number, a pair of guide grooves 20e, and holes 20f for a plurality of screws 21. A plurality of cam grooves 20c approximate a circle and become shallower in depth in the clockwise direction in FIG. 4. The cam lift plate 20 is fixed to the lower part of the machine body 1 by means of screws 21 (FIG. 2).
The pin 14 of the base disc 13 (FIG. 3) passes in order through the hole 17c of the operating member 17, a spring washer 22, a hole 20b of the cam lift plate 20, a compression coil spring 23 and a washer 24. The pin 14 is provided with a thrust stopper ring 25 located in the groove 14a thereof.
The pins 17e of the operating member 17 pass through the grooves 20e of the cam lift plate 20, and then the pins 17e are fitted with C-rings 26 in the grooves 17f thereof and guided in the guide grooves 20e around the pin 14 so that pins 17e may rotate at determined angle in relation to the cam lift plate 20. With respect to the vertical movement, member 17 and plate 20 are made integral as shown in FIGS. 8 and 9, and are pushed down by the compression coil spring 23 via the washer 24, stopper ring 25 and the pin 14 such that they hold the balls 19 between the cam grooves 20c of the cam lift plate 20 and the groove 13a of the base disc 13.
The operating portion 17a of the operating member 17 is formed with a projection 17g as seen in FIGS. 5 and 11, and when the element 18 is turned to the rest position, illustrated with the solid line in FIG. 5, the projection 17g (FIG. 11) is pushed under the base tubular member 6 and the member 17 is engaged at the rest position, illustrated with the solid line, due to a friction force.
Since each ball 19 is kept between the cam groove 20c and the groove 13a by action of the compression coil spring 23 and the member 17 is located under the base tubular member 6 via the projection 17g in the rest position so that the member 17 is moved together with the machine body, the device of the present invention makes no noise during operation of the sewing machine.
When the element 18 of the operating member 17 is at the rest position, illustrated with the solid line in FIG. 5, the ball 19 guided by the member 17 is positioned at the innermost part at a of the cam groove 20c (FIG. 10), and the sheet disc 16 provided on the lower surface of the base disc 13 is above the plain surface defined by the support feet 8, 9, 10 and 11 as shown in FIG. 6, from the machine mounting surface 15.
When the element 18 is rotated from the rest position, illustrated with the solid line in FIG. 5, to the operating position, illustrated with the dash-dotted line in the same, the ball 19 is moved, in the course of this rotation, from the innermost part a on the cam groove 20c to the shallower part of the groove, and the sheet disc 16 projects lower than said plain surface and contacts the machine mounting surface 15. When the operating member 17 is rotated under the condition that the machine body 1 is not rotated horizontally, the ball 19 engages in the groove 20d as shown in FIG. 13, and the machine body 1 contacts the surface 15 as shown in FIG. 7 only via the sheet disc 16.
Under this condition, the machine body 1 contacts the surface 15 via the balls 19 fitted in the ring groove 13a of the base disc 13 contacting the surface 15 via the sheet disc 16 and the engaging grooves 20d of the cam lift plate 20. If the machine body 1 is rotated horizontally, the balls 19 may rotate within the ring groove 13a of the base disc 13 under the condition that the balls 19 fit into the engaging grooves 20d, so that the machine body 1 may rotate by a slight force in relation to the surface 15.
Operation of the present invention will be explained below. The stitch forming mechanism is rotated to the use position thereof by the following procedure. The machine body 1 is rotated from the rest position to the operating position by rotation of the element 18. During this rotation, the balls 19 are moved from the innermost part a of the cam grooves 20c of their shallower parts, and the sheet disc 16 on the lower surface of the base disc 13 projects down farther than the plain surface of the feet 8 to 11 and contacts the machine positioning surface 15. Subsequently, the feet 8 to 11 become separated from the machine mounting surface 15, and when the operating member 17 is rotated continuously toward the operating position, the balls 19 fit into the engaging grooves 20d in FIGS. 12 and 13. Thus, the machine body 1 may be rotated horizontally by a slight force.
With respect to switching of the sewing machine from the use position of the lock stitching mechanism to the use position of the overlock stitching mechanism, it should be noted that when the machine body 1 is rotated in the clockwise direction from the condition, shown in FIG. 14 by a dash-dotted line, to the condition, shown by the solid line, and the operating member 17 is returned from the condition shown in FIG. 5 by the dash-dotted line to the rest position, shown with the solid line, the sheet disc 16 moves upwards, and the machine body 1 contacts the machine mounting surface 15 below the feet 8 to 11.
The overlock stitch mechanism is switched to the lock stitch mechanism by rotating the machine body 1 from the condition shown in FIG. 14 by the solid line in the counter-clockwise direction, by returning the operating member 17 from the position, shown by the dash-dotted line, to the rest position, shown by the solid line, then by moving the sheet disc 16 upwards so that the machine body 1 will contact the machine mounting surface 15 below the feet 8 to 11.
Due to the present invention, the machine body may be lifted from the machine mounting surface by an external and slight force, whereby the machine body can be rotated horizontally, and subsequently the machine body may be moved down to the mounting surface. Thus, switching to the desired stitch forming mechanism may be easily and exactly executed. | A rotation switching device for a sewing machine having a lock stitching mechanism and an overlock stitching mechanism. The device includes a rotatable operating member and a base disc connected to the operating member and movable in a vertical direction upon rotation of the operating member between a rest position in which the base disc is above the machine mounting surface and an operating position in which the base disc projects downward farther than the feet on the lower face of the machine body. In this position the base disc contacts the machine mounting surface to lift the body of the sewing machine from the mounting surface, whereby the body of the sewing machine may be rotated in a horizontal plane to place either the lock stitching mechanism or the overlock stitching mechanism to a use position. | 3 |
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to pressure equalization devices and particularly to apparatus for use in pressurizing or depressurizing feed chambers in which material to be delivered to the interior of a shaft furnace is temporarily stored. More specifically, this invention relates to reducing the wear of apparatus employed in the alternate pressurization and depressurization of a chamber, particularly an intermediate storage hopper in a shaft furnace charging installation, and also to reducing the noise level incident to operation of such apparatus. Accordingly, the general objects of the present invention are to provide novel and improved apparatus and methods of such character.
(2) Description of the Prior Art
Modern blast furnaces operate with high "counterpressures" in the region of the furnace throat. These throat pressures may reach or exceed a level of 3 kg/cm 2 . Efficient operation of such high pressure furnaces dictates that the burden or charge on the furnace hearth be replenished while the furnace is in operation and the charging must be accomplished without there being any appreciable pressure loss. In order to accomplish charging of a modern blast furnace, the materials to be deposited on the hearth may be delivered to and temporarily stored in an intermediate feed hopper which functions as a pressure equalizing chamber. U.S. Pat. No. 3,693,812 discloses a furnace charging installation including two intermediate feed hoppers. These intermediate feed hoppers are alternately isolated from the pressure conditions prevailing within the furnace and the ambient atmospheric pressure by sealing flaps or valves. The intermediate feed hoppers are operated in accordance with a predetermined cycle; i.e., while one of the hoppers is at atmospheric pressure and being filled with charge material the other will be at furnace pressure and will be discharging its contents into the furnace. Before refilling of a previously discharged intermediate feed hopper can be undertaken, the pressure in the hopper must be equalized with the ambient atmospheric pressure. Also, before the contents of a refilled feed hopper may be discharged into the furnace the pressure within the hopper must be equalized with that prevailing in the furnace throat. The requisite pressure equalization is typically accomplished by supplying blast furnace gas at furnace pressure to the intermediate feed hoppers and releasing this gas to the atmosphere as appropriate. The delivery of pressurized furnace gas to a feed hopper at atmospheric pressure and the venting of a pressurized intermediate feed hopper to the atmosphere is accomplished through the use of apparatus including pressure equalization valves. An example of a pressure equalization valve suitable for use with a shaft furnace may be found in U.S. Pat. 3,601,357.
The prior art systems for alternately pressurizing and depressurizing intermediate feed hoppers for blast furnaces which operate at high throat counter-pressures have been characterized by comparatively rapid deterioration of components and a high degree of noise during operation. These two problems, although of a different nature, are both caused by the rapid expansion and consequent large pressure drop of the gases which pass through the pressure equalization valves. The amount of wear suffered and the noise emitted is a direct function of the furnace throat pressure, the volume of the chamber in which the pressure is being equalized and the speed at which the equalization valve is actuated. The trend in blast furnace design is to increase furnace throat counter-pressure and also furnace size, increases in furnace size requiring larger intermediate feed hoppers, and thus the wear and noise problems are becoming aggravated. The solution of these problems has for some time been considered essential to permitting further progress in the development of more efficient blast furnaces.
To further discuss the problems of noise generation and wear in pressure equalization systems, when a pressure equalization valve is opened gases at a pressure which may equal or exceed 3 kg/cm 2 will pass through the valve and will expand downstream thereof. This expansion causes the gases to be accelerated to a speed which may approach or exceed the speed of sound. Wear is caused by entrained particles of dust which impact against metal parts, particularly the conduit walls downstream of the valve, thereby resulting in erosion of these parts. The noise resulting from the expansion of gases through the equalization valve largely occurs in a turbulence zone which forms immediately downstream of the valve.
While the noise resulting from operation of a pressure equalization system may be reduced to an acceptable level through the use of sound insulation materials and silencers, the problem of erosion has not previously been solved. The use of sound insulation material and silencers increases the cost and complexity of the pressure equalization system and the erosion requires periodic servicing for the purpose of replacing worn parts.
SUMMARY OF THE INVENTION
The present invention overcomes the above-briefly discussed and other deficiencies and disadvantages of the prior art by providing improved techniques and apparatus for equalizing the pressure in a chamber in an uncomplicated and economical manner.
In accordance with a preferred embodiment of the invention, suited for installation in a pressure equalization system associated with the intermediate feed hopper of a blast furnace which operates at a high throat counter-pressure, a movable housing is positioned immediately "downstream" from each of the pressure equalization valves associated with the hopper. Each of these movable housings includes means by which the jet of gas passing through the valves will be subdivided into a plurality of jets of small cross-section.
In one version of the invention the means for subdividing the stream or jet of gas passing through the pressure equalization valve comprises a plurality of serially arranged perforated discs. The perforations in each disc are offset with respect to those in the adjacent disc or discs.
The present invention concentrates the wear or erosion resulting from the discharge of pressurized and particle laden gas from a container in a preselected region. In accordance with the invention this region is within a movable housing mounted downstream from a pressure equalization valve. The components designed to be exposed to the abrasive effects of particles carried by the high speed gases are in the form of perforated discs. These perforated discs are preferably formed of a highly wear-resistant material and are also designed so as to be readily replaceable.
Also in accordance with the present invention, the noise produced by the expansion of a jet of gas downstream from a pressure equalization valve will be considerably reduced by subdividing the jet into a multiplicity of jets of reduced cross-section.
A further important characteristic of the present invention is that the subdivision of a plurality of jets of gas for the purpose of noise reduction is accomplished with the use of the same component or components which absorb the erosive effects of the particulate matter carried by the gases.
BRIEF DESCRIPTION OF THE DRAWING
The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawing wherein like reference numerals refer to like elements in the several figures and in which:
FIG. 1 is a schematic representation of a furnace charging installation including the pressure equalization system of the present invention;
FIG. 2 is a schematic representation, partly in section, of a pressure equalization system in accordance with a preferred embodiment of the present invention;
FIG. 3 is a side elevation view of the apparatus of FIG. 2 inverted for use in a manner opposite to that represented for the apparatus of FIG. 2;
FIG. 4 is a partial cross-sectional view, on an enlarged scale, of the embodiment of the invention depicted in FIGS. 2 and 3;
FIG. 5 is a plan view of one of the wear-absorbing elements shown in section in FIG. 4; and
FIG. 6 is a cross-sectional view, taken along line VI--VI of FIG. 5, of the wear-absorbing element of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawing, FIG. 1 depicts the application of the present invention to a bell-less blast furnace charging installation of the type disclosed in aforementioned U.S. Pat. No. 3,693,812. It will, however, be understood that the present invention is also applicable to other uses including incorporation in a prior art furnace charging installation of the type which employs conventional charging bells. In FIG. 1 the blast furnace is indicated at 1. The charge material or burden which is to be delivered to the hearth of the furnace will be delivered to and temporarily stored in a pair of intermediate feed hoppers 2 and 4. Material released from the feed hoppers 2 and 4 is delivered, via a central feed channel, to a rotatable and angularly adjustable charge distribution chute 6 located within furnace 1. Each of feed hoppers 2 and 4 is designed as a pressure equalization chamber. Referring to feed hopper 2, a lower sealing valve 8 and an upper sealing valve 10 are associated therewith and hopper 4 will be provided with similar valves. When the upper sealing valve 10 is in the open position, and the pressure within the feed hopper is thus equal to atmospheric pressure, charge material may be introduced into the feed hopper via a movable hopper 12 which is in turn fed from a conveyor 14.
Pressure equalization devices 16 and 18 are respectively provided for the purpose of establishing communication between the interior of feed hoppers 2 and 4 and the ambient atmosphere. The interior of feed hoppers 2 and 4 can, by respective pressure equalization devices 20 and 21, also be coupled to a source of pressurized gas 23. The pressurized gas delivered to the feed hoppers 2 and 4 via their respective equalization devices 20 and 21 may be either semi-purified furnace throat gas or an inert gas. As shown in FIG. 1, which is a typical installation, use is made 0f semi-purified furnace throat gas; the furnace throat gas passing through a purification apparatus and being thereafter delivered to the feed hoppers with very little loss of pressure.
Referring now to FIG. 2, the pressure equalization device 20 is depicted partly in section. Device 20 comprises a valve including a valve member 22 which is affixed to the end of an operating rod 24 for movement therewith as indicated by the double arrow in FIG. 2. Operation of valve member 22 between the closed position shown in solid lines and the open position shown by means of broken lines may, for example, be accomplished by use of the hydraulic control system of aforementioned U.S. Pat. No. 3,601,357. In the closed position the valve member 22 is in contact with a valve seat 26. The pressurized gas, for example from source 23, is delivered to the valve via a coupling flange and has been indicated by arrow A in FIG. 2.
Presuming that the feed hopper 2 of FIG. 1 has been refilled with charge material and the upper and lower sealing valves 10 and 8 closed, the interior of the hopper will be at atmospheric pressure. The pressure in the conduit upstream of valve member 22 may, for example, be approximately 2 kg/cm 2 . In order to reduce the noise caused by expansion of the pressurized gas through the device at the moment the valve member 22 is moved away from valve seat 26, and in order to concentrate the erosion resulting from the particulate matter entrained in the pressurized gas at an easily accessible place where the resulting damage can be repaired without difficulty, the present invention contemplates the installation of a mechanism immediately downstream of the valve seat 26. This mechanism includes a movable tubular housing 28. Removably positioned within housing 28 are one or more disc-shaped elements 30; three such elements 30a, 30b, 30c being shown in FIG. 2. The elements 30, in the preferred embodiment, are provided with a plurality of perforations and occupy the entire cross-sectional area of the passage defined by housing 28. The elements 30 are positioned downstream of valve seat 26 at a point where the maximum turbulence can be expected during operation of the pressure equalization device. The elements 30 will be described in greater detail below in the discussion of FIGS. 4 through 6.
Referring jointly to FIGS. 2 and 4, housing 28 has been designed in such a manner that it may be rotated out of the conduit in which the pressure equalizing valve is installed so as to give access to the disc members 30a, 30b and 30c and also to the valve seat 26 and the valve member 25. Housing 28 thus includes a lower flange 32 and an upper flange 34 which respectively interact to establish a fluid tight seal with a flange on the conduit system downstream of the valve and with a flange 36 which will be integral with the valve seat 26. Housing 28 moves about a pivot shaft 38 which is affixed to the exterior of the valve body. To release the housing 28 for movement, the connections between flanges 32 and 34 and their cooperating flanges are released or slackened and a suitable support means, not shown, is put into engagement with the underside of flange 36 in order to support and secure the upper portions of the pressure equalizing system. Thereafter, housing 28 is pivoted about shaft 38; typically through an angle of 180°. With housing 28 moved completely out of alignment with the fluid transmission system, the disc members 30a, 30b and 30c are easily accessible. It is also, at this time, possible to remove the valve seat 26 and, if deemed necessary or desirable subsequent thereto, to remove or service valve member 22 by moving it downwardly through the valve aperture.
The pressure equalization device depicted in FIG. 3 generally at 18 is employed to vent pressure within the feed hopper 4 to atmosphere. Pressure equalizing device 18 is identical to device 20 of FIG. 2 but, of course, is mounted in the opposite direction. Thus, as depicted in FIG. 3, the pivotal housing 28 of device 18 is above the actual valve since, as indicated by arrow B, the gas will escape from the feed hopper upon the opening of the pressure equalizing valve in the upward direction. The pressure equalization devices 21 and 16 are mounted in the same direction as valves 20 and 18 respectively.
Referring now to FIGS. 4-6 inclusive, the elements 30a, 30b and 30c are shown in detail as is the manner in which they are removably secured within the housing 28. As may best be seen from FIG. 5, the elements 30a, 30b and 30c are preferably in the form of perforated discs and each of these discs is provided with at least three apertured radial projections, such as projections 40, 42 and 46 on disc 30a, at its periphery. The perforations in disc 30a are indicated at 52; these perforations having been omitted from the showing of FIG. 4. Each of the discs is also provided with a raised rim 45. As shown in FIG. 4, the appropriate number of discs are stacked within housing 28 with the apertures in the peripheral radial projections being in alignment so that a bolt 48 may be passed through the aligned apertures and also through a support member 50 which is affixed to the inner wall of housing 28. The spacing between the discs is determined by the height of the rims 45. As installed within the housing 28, the discs are easily accessible and replaceable.
As previously noted, each of the discs 30 has a plurality of perforations 52. These perforations, in order to simplify the manufacturing process, will preferably be of cylindrical shape. Other shapes are, of course, possible. For maximum efficiency of operation, a plurality of discs should be employed and the perforations in adjacent discs should not be in alignment. Such an "offset" between the perforations in adjacent discs will cause the fluid passing through the device to follow zig-zag trajectories in order to pass through the perforated discs.
Particulate matter entrained with the gases passing through the pressure equalization devices will impact on the solid portions of the perforated discs 30 and the jet of gas expanding through each of the valves will be greatly reduced in speed and energy when passing through the discs whereby the erosive effects on the walls of conduits downstream of the equalizing devices is greatly reduced. The perforated discs are preferably formed of a very strong material, such as a manganese alloy steel. In addition to the ease of replacement of the discs 30, the present invention permits the wear of the discs to be easily inspected and the invention concentrates wear in a region where its effects are minimized and it is easy to repair. The subdivision of the jet of gas discharged through the valve of the pressure equalization device into a plurality of jets of smaller cross-section and lower energy significantly reduces the noise resulting from the expansion of the gases.
It is emphasized that the number of discs 30 and the manner in which their perforations are positioned and related disc-to-disc is variable. The principal requirement is that the number of discs and also their perforations should be such that the jet of fluid passing through the valve will be subdivided into small secondary jets which are caused to follow a zig-zag trajectory. The multiple discs 30 may, within the spirit and scope of the invention, be replaced by any other means which will achieve the same effect such as, for example, a stack of metallic balls.
Accordingly, while a preferred embodiment has been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention and it will be understood that the present invenion has been described by way of illustration and not limitation. | The pressurization and depressurization of a container, and specifically a feed hopper for materials to be delivered to the interior of a blast furnace, is accomplished with the aid of pressure equalization devices which each include a valve and a wear and sound reducing mechanism immediately downstream of the valve. The wear and sound reduction mechanism subdivides the stream of gas, which may contain entrained particulate matter, into a plurality of jets which are caused to follow a zig-zag trajectory. | 5 |
TECHNICAL FIELD
This invention relates to compounds having biological activity to inhibit lipoxygenase enzymes, to pharmaceutical compositions comprising these compounds, and to a medical method of treatment. More particularly, this invention concerns certain heteroatom substituted propanyl compounds which inhibit leukotriene biosynthesis, to pharmaceutical compositions comprising these compounds and to a method of inhibiting lipoxygenase activity and leukotriene biosynthesis.
BACKGROUND OF THE INVENTION
5-Lipoxygenase is the first dedicated enzyme in the pathway leading to the biosynthesis of leukotrienes. This important enzyme has a rather restricted distribution, being found predominantly in leukocytes and mast cells of most mammals. Normally 5-lipoxygenase is present in the cell in an inactive form; however, when leukocytes respond to external stimuli, intracellular 5-lipoxygenase can be rapidly activated. This enzyme catalyzes the addition of molecular oxygen to fatty acids with cis, cis-1,4-pentadiene structures, convening them to 1-hydropcroxy-trans, cis-2,4-pentadienes. Arachidonic acid, the 5-lipoxygenase substrate which leads to leukotriene products, is found in very low concentrations in mammalian cells and must first be hydrolyzed from membrane phospholipids through the actions of phospholipases in response to extracellular stimuli. The initial product of 5-lipoxygenase action on arachidonate is 5-HPETE which can be reduced to 5-HETE or convened to LTA 4 . This reactive leukotriene intermediate is enzymatically hydrated to LTB 4 or conjugated to the tripeptide glutathione to produce LTC 4 . LTA 4 can also be hydrolyzed nonenzymatically to form two isomers of LTB 4 . Successive proteolytic cleavage steps convert LTC 4 to LTD 4 and LTE 4 . Other products resulting from further oxygenation steps have also been described in the literature. Products of the 5-lipoxygenase cascade are extremely potent substances which produce a wide variety of biological effects, often in the nanomolar to picomolar concentration range.
The remarkable potencies and diversity of actions of products of the 5-lipoxygenase pathway have led to the suggestion that they play important roles in a variety of diseases. Alterations in leukotriene metabolism have been demonstrated in a as number of disease states including asthma, allergic rhinitis, rheumatoid arthritis and gout, psoriasis, adult respiratory distress syndrome, inflammatory bowel disease, endotoxin shock syndrome, atherosclerosis, ischemia induced myocardial injury, and central nervous system pathology resulting from the formation of leukotrienes following stroke or subarachnoid hemorrhage.
The enzyme 5-lipoxygenase catalyzes the first step leading to the biosynthesis of all the leukotrienes and therefore inhibition of this enzyme provides an approach to limit the effects of all the products of this pathway. Compounds which inhibit 5lipoxygenase are thus useful in the treatment of disease states such as those listed above in which the leukotrienes play an important role.
SUMMARY OF THE INVENTION
In its principal embodiment, the present invention provides certain heteroatom substituted propanyl compounds which inhibit lipoxygenase enzyme activity and are useful in the treatment of allergic and inflammatory disease states in which leukotrienes play a role.
The compounds of this invention and their pharmaceutically acceptable salts have the structure ##STR5## where L 1 and L 2 are independently a single bond or are independently selected from the group consisting of alkylene of one to three carbon atoms, propenylene, and propynylene.
L 3 is selected from the group consisting of
(a) ##STR6## and (b) ##STR7## where R 13 is hydrogen or alkyl of one to four carbon atoms, R 14 is alkyl of one to four carbon atoms, and R 15 is hydrogen or alkyl of one to four carbon atoms.
Y is selected from oxygen, >NR 12 where R 12 is hydrogen or alkyl of one to four carbon atoms, and >S(O) n where n=0, 1, or 2.
R 1 is alkyl of one to four carbon atoms; and R 2 is selected from the group consisting of (a) alkenyl of one to four carbon atoms,
(b) ##STR8## (c) ##STR9## and (d) ##STR10## where W is oxygen or sulfur, Z is --CH 2 --, oxygen, sulfur, or --NR 11 wherein R 11 is hydrogen or alkyl of one to four carbon atoms. R 9 is alkyl of one to four carbon atoms, or R 1 and R 9 , together with the nitrogen atoms to which they are attached, define a ring selected from the group consisting of ##STR11## where R 10 is selected from the group consisting of (a) hydrogen, (b) alkyl of one to four carbon atoms, (c) haloalkyl of one to four carbon atoms, (d) cyanoalkyl of one to four carbon atoms, (c) unsubstituted phenyl, (f) phenyl substituted with a substituent selected from the group consisting of alkyl of one to four carbon atoms, alkoxy of one to four carbon atoms, haloalkyl, of one to six carbon atoms, and halogen, (g) hydroxyalkyl of one to four carbon atoms, (h) aminoalkyl of one to four carbon atoms, (i) carboxyalkyl of one to four carbon atoms, (j) (alkoxycarbonyl)alkyl where the alkyl and alkoxy portions each are of one to four carbon atoms, and (k) (alkylaminocarbonyl)alkyl, where the alkyl portions are independently of one to four carbon atoms.
R 3 , R 4 , R 5 , and R 6 are independently selected from the group consisting of hydrogen, alkyl of one to four carbon atoms, alkoxy of one to four carbon atoms, haloalkyl of one to four carbon atoms, halogen, cyano, amino, alkoxycarbonyl of one to four carbon atoms, and dialkylaminocarbonyl where the alkyl portions are each of one to four carbon atoms.
R 7 and R 8 are alkyl of one to four carbon atoms, or taken together with the oxygen atoms to which they are attached and the carbon atoms to which the oxygen atoms in turn are attached, form a ring of the structure where R 16 and R 17 are independently selected from the group consisting of hydrogen, alkyl of one to four carbon atoms, alkoxy of one to four carbon atoms, and haloalkyl of one to four carbon atoms.
In another embodiment, the present invention provides pharmaceutical compositions which comprise a therapeutically effective amount of compound as defined above in combination with a pharmaceutically acceptable carder.
In yet another embodiment, the present invention provides a method of inhibiting leukotriene biosynthesis in a host mammal in need of such treatment comprising administering to a mammal in need of such treatment a therapeutically effective amount of a compound as defined above.
DETAILED DESCRIPTION OF THE INVENTION
Definitions of Terms
As used throughout this specification and the appended claims, the term is "alkyl" refers to a monovalent group derived from a straight or branched chain saturated hydrocarbon by the removal of a single hydrogen atom. Alkyl groups are exemplified by methyl, ethyl, n- and iso-propyl, n-, sec-, iso- and tert-butyl, and the like.
The term "alkylamino" refers to a group having the structure --NHR'wherein R' is alkyl as previously defined. Example of alkylamino include methylamino, ethylamino, iso-propylamino, and the like.
The term "alkylaminocarbonyl" refers to an alkylamino group, as previously defined, attached to the parent molecular moiety through a carbonyl group. Examples of alkylaminocarbonyl include methylaminocarbonyl, ethylaminocarbonyl, isopropylaminocarbonyl, and the like.
The term "alkanoyl" refers to an alkyl group, as defined above, attached to the parent molecular moiety through a carbonyl group. Alkanoyl groups are exemplified by formyl, acetyl, butanoyl, and the like.
The term "propanyl" refers to a straight chain, three-carbon group containing a carbon-carbon triple bond.
The term "hydroxyalkyl" represents an alkyl group, as defined above, substituted by one to three hydroxyl groups with the proviso that no more than one hydroxy group may be attached to a single carbon atom of the alkyl group.
The term "haloalkyl" denotes an alkyl group, as defined above, having one, as two, or three halogen atoms attached thereto and is exemplified by such groups as chloromethyl, bromoethyl, trifluoromethyl, and the like.
The terms "alkoxy" and "alkoxyl" denote an alkyl group, as defined above, attached to the parent molecular moiety through an oxygen atom. Representative alkoxy groups include methoxyl, ethoxyl, propoxyl, butoxyl, and the like.
The term "alkoxycarbonyl" represents an ester group; i.e. an alkoxy group attached to the parent molecular moiety through a carbonyl group. Representative alkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl, and the like.
The term "alkenyl" denotes a monovalent group derived from a hydrocarbon containing at least one carbon-carbon double bond by the removal of a single hydrogen atom. Alkenyl groups include, for example, ethenyl, propenyl, butenyl, 1-methyl-2-buten-1-yl and the like.
The term "alkylene" denotes a divalent group derived from a straight or branched chain saturated hydrocarbon by the removal of two hydrogen atoms, for example methylene, 1,2-ethylene, 1,1-ethylene, 1,3-propylene, 2,2dimethylpropylene, and the like.
The term "aminoalkyl" denotes an --NH 2 group attached to the parent molecular moiety through an alkylene group. Representative aminoalkyl groups include 2-amino-1-ethylene, 3-amino-1-propylene, 2-amino-1-propylene, and the like.
The term "carboxyalkyl" denotes a --CO 2 H group attached to the parent molecular moiety through an alkylene group. Representative carboxyalkyl groups include, 1-carboxyethyl, 2-carboxyethyl, 1-carboxypropyl, and the like.
The term "(alkoxycarbonyl)alkyl" denotes an alkoxycarbonyl group, as defined above, attached to the parent molecular moiety through an alkylene group. Representative (alkoxycarbonyl)alkyl groups include ethoxycarbonylmethyl, ethoxycarbonylethyl, methoxycarbonylpropyl, and the like.
The term "(alkylaminocarbonyl)alkyl" denotes an alkylaminocarbonyl group, as defined above, attached to the parent molecular moiety through an alkylene group. Examples of (alkylaminocarbonyl)alkyl groups include methylaminocarbonylmethyl, methylaminocarbonylpropyl, isopropylaminocarbonylmethyl, and the like.
The term "alkenylene" denotes a divalent group derived from a straight or branched chain hydrocarbon containing at least one carbon-carbon double bond. Examples of alkenylene include --CH═CH--, --CH 2 CH═CH--, --C(CH 3 )═CH--, --CH 2 CH═CHCH 2 --, and the like.
By "pharmaceutically acceptable salt" it is meant those salts which are, within the scope of sound medical judgement, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit/risk milo. Pharmaceutically acceptable salts are well known in the art. For example, S. M Berge, et al. describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66: 1-19. The salts can be prepared in situ during the final isolation and purification of the compounds of the invention, or separately by reacting the free base function with a suitable organic acid. Representative acid addition salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphersulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptonate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laumte, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate, undecanoate, valerote salts, and the like. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like, as well as nontoxic ammonium, quaternary ammonium, and amine cations, including, but not limited to ammonium, tetramethylammonium, tetmethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, and the like.
PREFERRED EMBODIMENTS
Compounds contemplated as falling withing the scope of the present invention include, but are not limited to:
E-(4S )-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane,
E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-acetyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane,
Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane,
E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane,
Z-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane,
E-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane,
Z-(4R )-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane,
E-(4R)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane,
Z-(4R )-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl}phenyl)oximinomethyl]-1,3-dioxolane,
E-(4R )-O-methyl-2,2-dimethyl-4-[(5- fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl}phenyl)oximinomethyl]-13-dioxolane,
Z-(4R )-O-methyl- 2,2-dimethyl-4-[(5- fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-13-dioxolane,
E-(4R)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-13-dioxolane,
Z-(4S )-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane,
E-(4S)-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane,
Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylsulfinyl)phenyl)oximinomethyl]-13-dioxolane,
E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylsulfinyl)phenyl)oximinomethyl]-1,3-dioxolane,
Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylsulfonyl)phenyl)oximinomethyl]-13-dioxolane,
E-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylsulfonyl)phenyl)oximinomethyl]-13-dioxolane,
Z-(4S ) -O-methyl-2,2-dimethyl-4-[(3-(4-(N', N'-dimethyl aminothiocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane,
E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N',N'-dimethylaminothiocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane,
Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-((N', N'-dimethylaminocarbonyl)-N-methylamino)benzylthioxy)phenyl)oximinomethyl]-13-dioxolane,
E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzylthioxy)phenyl)oximinomethyl]-13-dioxolane,
anti-(1 S, 2R)- 1-[(5-fluoro3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl) ]-1,2,3-trimethoxypropane,
anti-(1S, 2R)-1-[(5-fluoro-3-{4-(N-acetyl-N-methylamino)benzyloxy)phenyl)]-1,2,3 -trimethoxypropane,
anti-(1S, 2R)-1-[3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane,
anti-(1S, 2R)- 1-[3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane,
anti-(1S, 2R)-1-[5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzylthioxyl)phenyl]-1,2,3-trimethoxypropane,
Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-((4-(N', N'-dimethylaminocarbonyl-N-methylamino)methyl)benzyloxy)phenyl)oximinomethyl]-13-dioxolane,
E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-((4-(N', N'-dimethylaminocarbonyl-N-methylamino)methyl)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane,
Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(imidazolidin-2-on-1-ylmethyl)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane,
E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(imidazolidin-2-on-1-ylmethyl)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane,
Z- (1S)-O-methyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]]-1,2-dimethoxyethane,
E-(1S)-O-methyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]]-1,2-dimethoxyethane,
Z-(1S)-O-methyl-4-[(3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,2-dimethoxyethane,
E-(1S)-O-methyl-4-[(3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,2-dimethoxyethane,
E-(1S)-O-methyl-4- [(3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,2-dimethoxyethane,
Z-(1S)-O-methyl-4-[(3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,2-dimethoxyethane,
E-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N-acetyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane,
Z-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N-acetyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane,
E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane,
Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-allyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane,
E-(4S )-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino) thioxyl)phenyl)oximinomethyl]-13-dioxolane,
Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane,
anti-(1S, 2R)-1-[5-fluoro-3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl]- 1,2,3-trimethoxypropane,
anti-(1S, 2R)- 1-[5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl]-1,23-trimethoxypropane,
E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-(4-methylpipemzin-1-ylcarbonyl)-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane,
Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-(4-methylpipemzin-1-ylcarbonyl)-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-dioxlane,
anti-(1S, 2R)-1-[3-(4-(N-(4-methylpipemzin-1-ylcarbonyl)-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane,
E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(3-aminoprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-13dioxolane
Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(3-aminoprop-1-yl) aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane,
E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(4-hydroxybut- 1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-13dioxolane,
Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(4-hydroxybut-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane,
E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(3-carboxyprop-1-yl) aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane,
Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(3-carboxyprop-1-yl) aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3dioxolane,
E-(4S )-0-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(3-ethoxycarbonylprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane,
Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(N"-ethoxycarbonylprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane,
E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(N"-methylaminocarbonylprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane,
Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(N"-methylaminocarbonylprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane,
anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N'-methyl-N'-(3-aminoprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy) phenyl)]-1,2,3-trimethoxypropane,
anti-(1S, 2R)- 1-[(5-fluoro-3-(4-(N'-methyl-N'-(4-hydroxybut-1-ylaminocarbonyl-N-methylamino) benzyloxy)phenyl)]- 1,2,3-trimethoxypropane,
anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N'-methyl-N'-(3-carboxyprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)]-1,2,3-trimethoxypropane,
anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N'-methyl-N'-(3-ethoxycarbonylprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)]-1,2,3trimethoxypropane, and
anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N'-methyl-N'-(N "-methylaminocarbonylprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)]-1,2,3-trimethoxypropane.
Preferred compounds of the present invention have the structure defined above wherein R 1 is alkyl of one to four carbon atoms; R 2 is selected from
(a) alkenyl of one to four carbon atoms,
(b) ##STR12## and (c) ##STR13## where W is oxygen, R 9 is alkyl of one to four carbon atoms, and R 10 is alkyl of one to four carbon atoms; L 1 is a valence bond; L 2 is a valence bond or alkyl of one to four carbon atoms; L 3 is selected from
(a) ##STR14## where R 13 is hydrogen and R 14 is alkyl of one to four carbon atoms, and
(b) ##STR15## where R 15 is hydrogen or alkyl of one to four carbon atoms; R 7 and R 8 are alkyl of one to four carbon atoms, or taken together define a group of formula ##STR16## where R 16 and R 17 are independently selected from hydrogen and alkyl of one to four carbon atoms; Y is selected from oxygen and >S(O)n where n=0, 1, or 2; and R 3 , R 4 , R 5 , and R 6 are as defined above.
Particularly preferred compounds of the present invention have the structure defined immediately above wherein L 2 is a valence bond and Y is S. Examples include:
E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3dioxolane,
E-(4S )-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-acetyl-N-methylamino)benzyloxy)phenyl) -1,3-dioxolane, and
E-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane.
The most preferred compounds of the present invention are:
Z-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane,
E-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane,
Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane,
E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane,
E-(4R)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-13-dioxolane,
anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)]-1,2,3-trimethoxypropane, and
anti-(1S, 2R)-1-[(5-fluoro-3-{4-(N-acetyl-N-methylamino)-benzyloxy)phenyl)]-1,2,3-trimethoxypropane.
Certain compounds of this invention may exist in either cis or trans or E or Z isomers with respect to the oxime geometry and in addition to stereoisomeric forms by virtue of the presence of one or more chiral centers. The present invention contemplates all such geometric and stereoisomers, including R- and S-enantiomers, diastereomers, and cis/trans or E/Z mixtures thereof as falling within the scope of the invention. If a particular enantiomer is desired, it may be prepared by asymmetric synthesis or by derivatization with a chiral auxiliary and the resulting diastereomeric mixture is separated and the auxiliary group cleaved to provide the pure desired enantiomers.
Lipoxygenase Inhibition Determination
Inhibition of leukotriene biosynthesis was evaluated in an assay, involving calcium ionophore-induced LTB 4 biosynthesis expressed human whole blood. Human heparinized whole blood was preincubated with test compounds or vehicle for 15 min at 37° C. followed by calcium ionophore A23187 challenge (final concentration of 8.3 μM) and the reaction terminated after 30 min by adding two volumes of methanol containing prostaglandin B 2 as an internal recovery standard. The methanol extract was analyzed for LTB 4 using a commercially available radioimmunoassay.
The compounds of this invention inhibit leukotriene biosynthesis as illustrated in Table 1.
TABLE 1______________________________________In Vitro Inhibitory Potencies of Compoundsof this Invention Against 5-Lipoxygenase fromStimulated LTB.sub.4 Formation in Human Whole BloodExample IC.sub.50 (10.sup.-6 M)______________________________________1 100% @ 0.100 μM2 82% @ 0.20 μM3 99% @ 6.25 μM(Z oxime)3 0.05(E oxime)4 100% @ 6.25 μM5 100% @ 0.78 μM14 49% @ 0.10 μM15 42% @ 0.78 μM______________________________________
Pharmaceutical Compositions
The present invention also provides pharmaceutical compositions which comprise compounds of the present invention formulated together with one or more non-toxic pharmaceutically acceptable carriers. The pharmaceutical compositions may be specially formulated for oral administration in solid or liquid form, for parenteral injection, or for rectal administration.
The pharmaceutical compositions of this invention can be administered to s humans and other animals orally, rectally, parenterally, intracisternally, intravaginally, intraperitoneally, topically (as by powders, ointments, or drops), bucally, or as an oral or nasal spray. The term "parenteral" administration as used herein refers to modes of administration which include intravenous, intramuscular, intraperitoneal, intrasternal, subcutaneous and intraarticular injection and infusion.
Pharmaceutical compositions of this invention for parenteral injection comprise pharmaceutically acceptable sterile aqueous or nonaqueous solutions, dispersions, suspensions or emulsions as well as sterile powders for reconstitution into sterile injectable solutions or dispersions just prior to use. Examples of suitable aqueous and nonaqueous carriers, diluents, solvents or vehicles include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), and suitable mixtures thereof, vegetable oils (such as olive oil), and injectable organic esters such as ethyl oleate. Proper fluidity can be maintained, for example, by the use of coating materials such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants.
These compositions may also contain adjuvants such as preservatives, wetting agents, emulsifying agents, and dispersing agents. Prevention of the action of microorganisms may be ensured by the inclusion of various antibacterial and antifungal agents, for example, paraben, chlorobutanol, phenol sorbic acid, and the like. It may also be desirable to include isotonic agents such as sugars, sodium chloride, and the like. Prolonged absorption of the injectable pharmaceutical form may be brought about by the inclusion of agents which delay absorption such as aluminum monostearate and gelatin.
In some cases, in order to prolong the effect of the drug, it is desirable to slow the absorption of the drug from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material with poor water solubility. The rate of absorption of the drug then depends upon its s rate of dissolution which, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally administered drug form is accomplished by dissolving or suspending the drug in an oil vehicle.
Injectable depot forms are made by forming microencapsule matrices of the drug in biodegradable polymers such as polylactide-polyglycolide. Depending upon the ratio of drug to polymer and the nature of the particular polymer employed, the rate of drug release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides) Depot injectable formulations are also prepared by entrapping the drug in liposomes or microemulsions which are compatible with body tissues.
The injectable formulations can be sterilized, for example, by filtration through a bacterial-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium just prior to use.
Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the active compound is mixed with at least one inert, pharmaceutically acceptable excipient or carder such as sodium citrate or dicalcium phosphate and/or a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and silicic acid, b) binders such as, for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose, and acacia, c) humectants such as glycerol, d) disintegrating agents such as agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate, e) solution retarding agents such as paraffin, f) absorption accelerators such as quaternary ammonium compounds, g) wetting agents such as, for example, cetyl alcohol and glycerol monostearate, h) absorbents such as kaolin and bentonite clay, and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may also comprise buffering agents.
Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like.
The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings and other coatings well known in the pharmaceutical formulating art. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions which can be used include polymeric substances and waxes.
The active compounds can also be in micro-encapsulated form, if appropriate, with one or more of the above-mentioned excipients.
Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethyl as formamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof.
Besides inert diluents, the oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents.
Suspensions, in addition to the active compounds, may contain suspending agents as, for example, ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar, and tragacanth, and mixtures thereof.
Compositions for rectal or vaginal administration are preferably suppositories which can be prepared by mixing the compounds of this invention with suitable nonirritating excipients or carders such as cocoa butter, polyethylene glycol or a suppository wax which are solid at room temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the active compound.
Compounds of the present invention can also be administered in the form of liposomes. As is known in the art, liposomes are generally derived from phospholipids or other lipid substances. Liposomes are formed by mono- or multi-lamellar hydrated liquid crystals that are dispersed in an aqueous medium. Any nontoxic, physiologically acceptable and metabolizable lipid capable of forming liposomes can be used. The present compositions in liposome form can contain, in addition to a compound of the present invention, stabilizers, preservatives, excipients, and the like. The preferred lipids are the phospholipids and the phosphatidyl cholines (lecithins), both natural and synthetic.
Methods to form liposomes are known in the art. See, for example, Prescott, Ed., Methods in Cell Biology, Volume XIV, Academic Press, New York, N.Y. (1976), p. 33 et seq.
Dosage forms for topical administration of a compound of this invention include powders, sprays, ointments and inhalants. The active compound is mixed under sterile conditions with a pharmaceutically acceptable carrier and any needed preservatives, buffers, or propellants which may be required. Opthalmic formulations, eye ointments, powders and solutions are also contemplated as being within the scope of this invention.
Actual dosage levels of active ingredients in the pharmaceutical compositions of this invention may be varied so as to obtain an amount of the active compound(s) that is effective to achieve the desired therapeutic response for a particular patient, compositions, and mode of administration. The selected dosage level will depend upon the activity of the particular compound, the route of administration, the severity of the condition being treated, and the condition and prior medical history of the patient being treated. However, it is within the skill of the art to start doses of the compound at levels lower than required for to achieve the desired therapeutic effect and to gradually increase the dosage until the desired effect is achieved.
Generally dosage levels of about 1 to about 50, more preferably of about 5 to about 20 mg of active compound per kilogram of body weight per day are as administered orally to a mammalian patient. If desired, the effective daily dose may be divided into multiple doses for purposes of administration, e.g. two to four separate doses per day.
Preparation of the Compounds of the Invention
The compounds of this invention may be prepared by a variety of synthetic routes. Representative procedures are outlined as follows. It should be understood that L 1 , L 2 , R 1 , R 2 , R 3 , R 4 , R 7 , R 13 , R 14 , R 15 , and R 16 as used herein, correspond to the groups identified above.
The preparation of trialkoxypropane derivatives is shown in Scheme 1. Aryl bromide 1, prepared according to the method described in EPA 385 679, is metallated using, for example, n-butyllithium, in an organic solvent such as THF. Addition of 2,2-dimethyl-1,3-dioxolane to the aryllithium provides alcohol 2 which is converted to ether 3 by reaction with NaH and R 13 X, where R 13 is defined above and X is a suitable leaving group such as CI, Br, I, methanesulfonyl, or p-toluenesulfonyl. Hydrolysis of the dioxane by treatment with catalytic p-toluenesulfonic acid in methanol affords diol 4 which is converted to trialkoxy compound 5 by reaction with NaH and R 7 X where R 7 and X are defined above. Catalytic hydrogenolysis over palladium on carbon of 5 affords the intermediate phenol 6. Reaction of 6 with NaH and a compound of formula Ar 1 -L 2 -X, where L 2 , and X are defined above, provides 7, which is a representative compound of the invention. ##STR17##
The preparation of dioxolane-containing compounds of the invention is shown in Scheme 2. Diol 4, prepared as shown in Scheme 1, is condensed with carbonyl compound R 15 R 16 CO where R 15 and R 16 are defined above under standard ketalization conditions to provide 8. The desired compound 9.9 is then prepared by hydrogenolysis of 8, followed by alkylation of the resulting phenol with Ar 1 -L 2 -X as described in Scheme 1. ##STR18##
The preparation of oxime-containing compounds of the invention is shown in Scheme 3. Alcohol 2, prepared as in Scheme 1, is oxidized to ketone 10, for example using Swern oxidation conditions (Swern, D., Manusco, A. J., and Huang, S. L., J. Org. Chem., 1978, 43, 2480). Reaction of 10 with HNOR 14 , where R 14 is defined above affords oxime 11. Hydrolysis 11 as described in Scheme 1 provides key intermediate 12, which is converted to the desired trialkoxypropane 16 or dioxolane 15 as outlined in Schemes 1 and 2 respectively. ##STR19##
The preparation of the preferred compounds of the invention is outlined in Scheme 4. 3-(p-nitrobenzenethioxy)bromobenzene 17 was prepared by coupling of m-bromobenzenethiol and p-nitrobromobenzene. Reduction of 17, for example with potassium borohydride and CuCl, gives amine 18 which is formylated according to the procedure of Krishnamurthy (Tetrahedron Lett. 1982, 23, 3315) to provide N-formyl compound 19. Treatment of 19 with NaH and R 1 X where R 1 is alkyl and X is Br, Cl, or I, followed by hydrolysis with aqueous NaOH provides alkylamine 20. Reaction of 20 with NaH and allyl bromide provides 21, which is converted to the desired compound 22 as outlined in Schemes 1-3. Compounds in which R 2 is R 9 R 10 NCO are prepared by treatment of 23 with a suitable base such as lithium hexamethyldisylazide and carbamoyl chloride R 9 R 10 NCOCl. ##STR20##
The preparation of the compounds of this invention where R 10 is haloalkyl or aminoalkyl is shown in Scheme 5. Amine 23, prepared as in Scheme 4, is treated with the desired haloalkylisocyanate to form haloalkyl derivative 25. Conversion of 25 to azide 26, for example with sodium azide, and alkylation with sodium hydride and R 9 X as described above provides 27, which is reduced to the desired aminoalkyl compound 28 by treatment with 1,3-propanedithiol. ##STR21##
The preparation of the compounds of this invention where R 10 is hydroxyalkyl, carboxyalkyl, (alkoxycarbonyl)alkyl, or (alkylaminocarbonyl)alkyl, is shown in Scheme 6. Amine 23, prepared as in Scheme 4, is treated with an alkoxycarbonylalkylisocyanate to provide the alkoxycarbonylalkyl derivative 29, which is alkylated by treatment with NaH and R9X as described above to form 30. Hydrolysis of ester 30 provides carboxyalkyl derivative 31. Reduction of 30 with lithium borohydride or 31 with BH 3 provides hydroxyalkyl compound 32. The (alkylaminocarbonyl)alkyl derivatives 33 are prepared from ester 30, or acid 31 by standard synthetic methods. ##STR22##
The preparation of the arylpropynyl-, arylpropenyl-, and arylpropyl-aryl ether compounds of the invention is shown in Scheme 6. 4-iodoaniline is converted to urea 34 by acylation with dimethylcarbamyl chloride, followed by alkylation with NaH and R 1 X. Coupling of 34 with propargyl alcohol provides propynol 35 which is converted to chloride 36 by treatment with phosphorus trichloride. The desired arylpropynyl-aryl ether 37 is then prepared as described in Schemes 1-3.
Reduction of alkynol 35 with Red-Al (sodium bis(2-methoxyethoxy)aluminum hydride) provides trans allylic alcohol 38, which is converted to the desired compound 39 as described above. Catalytic hydrogenation of 39, for example with palladium on carbon, provides saturated compound 40. ##STR23##
The foregoing may be better understood by the following Examples, which are presented for purposes of illustration and are not intended to limit the scope of the invention.
EXAMPLE 1
Preparation of E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane.
Step 1: (4R, 1'R)- and(4R, 1'S)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethoxy)phenyl)hydroxymethyll-1,3-dioxolane.
A flame-dried flask was charged with 3-(napth-2-ylmethoxy)-5-fluorobromobenzene (0.86 g. 2.6 mmol), prepared according to the method of EPA 385 679, a stir bar, and freshly dried tetrahydrofuran (THF, 23 mL). The resulting solution was cooled to -78 ° C. under a nitrogen atmosphere and n-butyllithium (2.5M in hexanes, 1.04 mL, 2.6 mmol) was added slowly in a dropwise fashion via syringe. After stirring for 10 minutes at -78 ° C. a THF solution (6 mL) of (R)-(+)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde (0.34 g, 2.6 mmol), prepared as described in Jackson, Synthetic Commun. 1988, 18(4), 337-341) was added. The resulting solution was stirred for 30 minutes at -78 ° C., and the cooling bath was removed. The reaction was stirred for 1 hour and then quenched with excess saturated aqueous NH 4 Cl. The mixture was partitioned between saturated aqueous NH 4 Cl and ethyl acetate. The organic layer was washed twice with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to provide a cloudy oil which was purified by chromatography on silica gel (20% ether:hexanes) to give the less polar anti-(4R, 1'S) alcohol (0.193 g, 20%), a mixture of both isomers (0.233 g, 23%), and the more polar syn-(4R, 1'R) alcohol (0.149 g, 15%).
Step 2: (4R)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2ylmethoxy)phenyl)carbonyl. methyl]- 1,3-dioxolane.
Following the Swern oxidation procedure (Swern, D.; Manusco, A. J.; Huang, S. L.,J. Org. Chem. 1978, 43, 2480) a mixture of (4R, 1'R)- and (4R, 1'S)-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(napth-2ylmethoxy)phenyl)hydroxymethyl]-1,3-dioxolane (0.55 mg, 1.44 mmol), prepared as in step 1, was oxidized to the corresponding ketone (350 mg, 66%) after chromatography on silica gel.
Step 3: Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethoxy)phenyl)oximinomethyl]-1,3-dioxolane.
To a solution of (4R)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethoxy)phenyl)carbonylmethyl]-1,3-dioxolane (50 mg, 0.132 mmol), prepared as in step 2, in ethanol (0.5 mL) were added sequentially 0-methyl-hydroxylamine hydrochloride (55 mg, 0.66 mmol) and pyridine (53 ]μL, 0.66 mmol). The resulting solution was stirred at 40° C. for 1 hour and the volatiles were removed in vacuo. The resulting residue was partitioned between ethyl acetate and water. The aqueous layer was separated and extracted twice with ethyl acetate. The combined organic layers were were washed once with saturated aqueous NH 4 Cl, twice with brine, dried over MgSO 4 , filtered, and concentrated in vacuo. The isomers were separated by chromatography on silica gel (1.0% ethyl acetate/hexanes) to give in the order of elution the pure Z-oxime isomer (14.5 rag, 27%), a mixture of both isomers (24.3 mg, 45%), and the pure E-oxime isomer (6.5 mg, 12%). Z-isomer: 1 H NMR (300 MHz, CDCl 3 ) δ 7.83-7.90 (4H, m), 7.47-7.54 (3H, m), 7.06 (1H, br s), 6.93 (1H, ddd, J=10, 1.5, 2.5 Hz), 6.73 (1H, dr, J=10, 3, 3 Hz), 5.46 (1H, t, J=7 Hz), 5.22 (2H, s), 4.43 (1H, dd, J=7.5, 9 Hz), 3.98 (3H, s), 3.83 (1H, dd, J=9, 7.5 Hz), 1.37 (3H, s), 1.28 (3H, s). MS m/e 410 (M+H) + , 427 (M+NH 4 ) + . Analysis calc'd for C 24 H 24 NO 4 F: C, 70.40; H, 5.91; N, 3.42. Found: C, 70.30; H, 5.95; as N, 3.43. E-isomer: 1H NMR (300 MHz, CDCl 3 ) 6 7.83 -7.90 (4H, m), 7.47-7.54 (3H, m), 6.84 (1H, br s), 6.70-6.78 (2H, m), 5.22 (2H, s), 4.85 (1H, t; J=7.5 Hz), 4.12 (1H, dd, J=7.5, 9 Hz), 3.91 (1H, dd, J=9, 7.5 Hz), 3.84 (3H, s), 1.38 (3H, s), 1.29 (3H, s). MS m/e 410 (M+H) + , 427 (M+NH 4 ) + . Analysis calc'd for C 24 H 24 NO 4 F: C, 70.40; H, 5.91; N, 3.42. Found: C, 70.30; H, 5.95; N, 3.43.
Step 4: E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-hydroxyphen-1-yl)oximinomethyl]-1,3-dioxolane.
A flask was charged with 10% Pd/C (130 mg) and a solution in ethanol (4.5 mL) of E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethoxy)phenyl)oximinomethyl]-1,3-dioxolane (450 mg, 1.1 mmol), prepared as in step 3, was added. The reaction mixture was evacuated and flushed with hydrogen (3 cycles) and maintained under 1 atmosphere of hydrogen at ambient temperature for 1 hour. The reaction mixture was flushed with nitrogen and filtered through a pad of celite. The filter cake was rinsed thoroughly with ethanol and the combined flitrates were concentrated in vacuo. Purification by chromatography on silica gel (10% ethyl acetate/hexanes) gave E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-hydroxyphen-1-yl)oximinomethyl]-1,3-dioxolane as a colorless oil (259 mg, 86%).
Step 5: methyl 4-(N-methylaminocarbonyl)aminobenzoate.
A solution of methyl 4-aminobenzoate (15 g, 99 mmol), and methyl isocyanate (11.8 mL, 200 mmol) in toluene (400 mL) was heated at 100° C. under N2 for 3 hours during which time a precipitate formed slowly. Additional methyl isocyanate (11.8 mL, 200 mmol) was added and heating was continued for 2 hours. The reaction mixture was cooled to 0° C. and filtered. The precipitate was washed with ether and vacuum-dried to give methyl 4-(N-methylaminocarbonyl)aminobenzoate as a colorless solid (17.5 g, 85%).
Step 6: methyl 4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzoate.
To a 0° C. suspension of NaH (80% oil dispersion, 3.60 g, 120 mmol) in THF (200 mL) under N 2 was added a solution of methyl 4-(N-methylaminocarbonyl)aminobenzoate (10.0 g, 48 mmol), prepared as in step 5, in THF (40 mL). The reaction mixture was stirred at 0° C. until gas evolution ceased, then the cold bath was removed and stirring was continued for 1.5 hours. A solution of iodomethane (6.6 mL, 106 mmol) in DMF (24 mL) was added and the reaction mixture was stirred for 72 hours at ambient temperature. NaH (2.0 g) , and as iodomethane (5.0 mL) were then added and the reaction mixture was stirred for an additional 2 hours. The reaction mixture was poured slowly into ice-water and the organics were stripped off in vacuo. The aqueous solution was extracted with ethyl acetate (10 x). The combined organic layers were dried over MgSO 4 , filtered, and concentrated. Pure methyl 4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzoate (6.62 g, 58%) was obtained as a colorless oil which crystallized on standing after chromatography on silica gel (40%, then 50% ethyl acetate / hexanes). mp 71°-73° C.
Step 7: 4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyl alcohol.
To a 0° C. solution of methyl 4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzoate (1.50 g, 6.35 mmol), prepared as in step 6, in THF (11.4 mL) was added lithium triethylborohydride (1.0 M solution in THF, 14 mmol). The reaction mixture was stirred for 1 hour. Water (3.0 mL) and H 2 O 2 (30% aqueous solution, 5.0 mL) were added cautiously and the reaction mixture was stirred at 45° C. for 20 min. Aqueous HCL (6 M, 8.0 mL) was added and the reaction mixture was stirred at reflux for 14 hours. The reaction mixture was cooled to ambient temperature and poured into ethyl acetate. The aqueous phase was extracted three times with ethyl acetate. The combined organic layers were dried over MgSO 4 , filtered, and concentrated in vacuo. 4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyl alcohol (797 mg, 61%) was isolated as a colorless solid by chromatography on silica gel (ethyl acetate). mp 65°-66° C.
Step 8: 4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyl chloride.
To a stirred solution at -23° C. under N 2 of 4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyl alcohol (77.0 rag, 0.37 mmol), prepared as in step 7, in dry CH 2 C12 (3.7 mL) was added triethylamine (67.0 μL, 0.48 mmol), and mcthanesulfonyl chloride (34.0μL, 0.44 mmol). The reaction mixture was stirred at ambient temperature until TLC indicated complete reaction (˜5 hours). The resultant solution was poured into ethyl acetate and the organic phase was washed (2 X, water; 2 X, brine), dried (MgSO 4 ), filtered and concentrated in vacuo. Purification by flash chromatography on silica gel (70% ethyl acetate / hexane) provided 4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyl chloride (56.0 mg, 67.0%) as a colorless oil which crystallized on standing at -25 ° C. mp 38.5°-39 ° C. 1H NMR (300 MHz, CDCl 3 ) δ 7.34 (2H, d, J=8.5 Hz), 7.04 (2H, d, J=8.5 Hz), 4.57 (2H, s), 3.22 (3H, s), 2.71 (6H, s). MS m/e 227 (M+H) + , 244 (M+NH 4 ) + . Step 9: E-(4S)-O-Methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl-1,3: dioxolane.
To a flask containing E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-hydroxyphen-1-yl)oximinomethyl]-1.3-dioxolane (160 mg, 0.59 mmol) in dry DMF (10 mL) was added sodium hydride (80% oil dispersion, 20 mg, 0.65 mmol). After gas evolution ceased, 4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyl chloride (134 mg, 0.59 mmol) was added in a single portion. The reaction was stirred for 3 hours and partitioned between ethyl acetate and saturated aqueous ammonium chloride. The aqueous layer was drawn off and extracted with ethyl acetate (3x, 10 mL). The combined organic layers were washed with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to give an orange oil. Purification by chromatography on silica gel (30% ethyl acetate:hexanes) provided pure E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximino -1.3-dioxolane (170 mg, 62%). 1H NMR (300 MHz, CDCI3) δ7.37 (2H, d, J=9 Hz), 7.39 (2H, d, J=9 Hz), 6.81 (1H, br s), 6.67-6.77 (2H, m), 4.98 (2H, s), 4.86 (1H, t, J=7.5 Hz), 4.13 (1H dd, J=8.5, 7.5 Hz), 3.92 (1H, dd, J=8.5, 7.5 Hz), 3.87 (3H, s), 3.23 (3H, s), 2.71 (6H, s), 1.39 (3H, s), 1.32 (3H, s). MS m/e 460 (M+H) + , 477 (M+NH 4 ). Analysis calc'd for C 24 H 30 N 3 O 5 F: C, 62.73; H, 6.58; N, 9.14. Found: C, 62.56; H, 6.66; N, 9.08.
EXAMPLE 2
Preparation of E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-acetyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane.
Step 1: 4,-(N-acetyl-N-methylamino)benzoic acid.
To a solution of N-methyl-4-aminobenzoic acid (2.0 g, 13.2 mmol) dissolved in anhydrous pyridine (13.2 mL) was added acetic anhydride (1.4 mL, 14.5 mmol). The reaction was stirred at ambient temperature until TLC indicated complete reaction (˜22 hours). The resulting solution was poured into ethyl acetate and the organic phase was washed (3 X, 10% HCl; 1 X, water; 1 X, brine), dried (MgSO 4 ), filtered, and concentrated in vacuo to provide the corresponding amide as a colorless solid. Recrystallization (ethyl acetate / hexane) afforded pure 4-(N-acetyl-N-methylamino)benzoic acid (2.15 g, 84.0%). 1 H NMR (300 MHz, CDCl 3 ) δ8.18 (2H, br d, J=8.5 Hz), 7.33 (2H, br d, J=8.5 Hz), 3.33 (3H, s), 2.0 (3H, br s) MS m/e 194 (M+H) + , 211 (M+NH 4 ) + .
Step 2. Preparation of 4-(N-acetyl-N-methylamino)benzyl alcohol.
An oven dried flask, under nitrogen flow, was charged with a stir bar, 4-(N-acetyl-N-methylamino)benzoic acid (1.0 g, 5.18 mmol), prepared as in step 1, anhydrous DME (10.3 mL), and anhydrous DMF (3.0 mL). The resulting solution was cooled to -20 ° C., and 4-methylmorpholine (0.60 mL, 5.4 mmol) and isobutyl chloroformate (0.70 mL, 5.4 mmol) were added sequentially via syringes. The reaction mixture was stirred under N 2 at -20° C. for 1 h. The resulting yellow mixture was filtered and the precipitate washed with DME (2 X, ˜1 mL). The combined filtrate and washings were cooled to 0° C. and a solution of sodium borohydride (800 mg, 21.1 mmol) in water (2.0 mL) was added dropwise. The reaction was stirred at 0° C. for 15 min. and quenched with saturated aqueous ammonium chloride. The resulting mixture was partitioned between ethyl acetate and brine. The combined organic layers were dried (MgSO 4 ), filtered and concentrated in vacuo to give an oil. Purification by flash chromatography on silica gel (90% ethyl acetate / hexane) provided the corresponding alcohol as a colorless oil which solidified on standing. Recrystallization from hexane provided 4-(N-acetyl-N-methylamino)benzyl alcohol as a colorless solid (543.0 mg, 58.5%). 1 H NMR (300 MHz, CDCl 3 ) δ7.45 (2H, d, J =8.5 Hz), 7.18 (2H, d, J=8.5 Hz), 4.75 (2H, s), 3.27 (3H, s), 1.90 (3H, br MS m/e 180 (M+H) + , 197 (M+NH 4 ) + .
Step 3. Preparation of 4-(N-acetyl-N-methylamino)benzyl bromide.
To a solution of 4-(N-acetyl-N-methylamino)benzyl alcohol (543.0 mg, 3.0 mmol), prepared as in step 2, dissolved. in dry CH 2 Cl 2 (11.5 mL) was added dropwise 1M PBr 3 in CH 2 Cl 2 (3.6 mL, 3.6 mmol) at 0° C. The reaction was stirred at ambient temperature until TLC indicated complete reaction (˜5 hours). The resulting solution was partitioned between ethyl acetate and brine. The combined organic layers were decolorized with charcoal, dried (MgSO 4 ), filtered through celite and concentrated in vacuo. Purification by flash chromatography on silica gel (40% ethyl acetate / hexane) provided 4-(N-acetyl-N-methylamino)benzyl bromide as a colorless solid (595 mg, 81.0%). 1 H NMR (300 MHz, CDCl 3 ) δ7.46 (2H, d, J=8.5 Hz), 7.18 (2H, d, J=8.5 Hz), 4.50 (2H, s), 3.27 (3H, s), 1.88 (3H, br s). MS m/e 242 (M+H) + , 259/261 (M+NH 4 ) + . Analysis calc'd for C 10 H 12 NOBr: C, 49.61; H, 5.00; N, 5.79. Found: C, 49.35; H, 4.97; N, 5.65.
Step 4: E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-acetyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-13-dioxolane.
The desired compound was prepared according to the method of Example 1, step 9, except substituting 4-(N-acetyl-N-methylamino)benzyl bromide, prepared as in step 3, for 4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyl chloride. Chromatography on silica gel (50% ethyl acetate:hexanes) provided E-(4R)-O-methyl-2,2-dimethyl -4- [(5-fluoro-3-(4-(N-acetyl-N-methylamino)benzyloxy)phenyl )oximinomethyl]-1,3-dioxolane. 1 H NMR (300 MHz, CDCl 3 ) δ7.48 (2H, d, J=9 Hz), 7.22 (2H, d, J=9 Hz), 6.82 (1H, br s), 6.76 (1H, br d, J=9.5 Hz), 6.72 (1H, dr, J=10.5, 3 Hz), 5.06 (2H, s), 4.87 (1H, tt, J=7 Hz), 4.13 (1H, dd, J=7.5, 8 Hz), 3.92 (1H, dd, J=7.5, 9 Hz), 3.87 (3H, s), 3.28 (3H, br s), 1.89 (3H, br s), 1.39 (3H; s), 1.32 (3H, s). MS m/e 43 1 (M+H) + , 448 (M+NH 4 ) + . Analysis calc'd for C 23 H 27 N 2 O 5 F(0.25 H 2 O): C, 63.51; H, 6.37; N, 6.44. Found: C, 63.39; H, 6.37; N, 6.34.
EXAMPLE 3
Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl) -1,3-dioxolane.
Step 1:3 -(p-nitrobenzenethioxy)bromobenzene.
A 500 mL round bottomed flask equipped with a magnetic stirbar was charged with sodium hydride (3.78 g of a 60% oil dispersion, 95 mmol), and freshly dried THF (200 mL) under a stream of nitrogen. To the stirred suspension was added t-butanol (8 mL). When hydrogen gas evolution ceased, m-bromobenzenethiol (12.0 g, 63 mmol) was via syringe over 5 rain and the resulting solution was stirred for 10 min. To this solution was added in a single portion p-nitrobromobenzene (10.7 g, 52.9 mmol). The solution was stirred at room temperature for 45 min and sodium hydride (0.5 g of a 60% oil dispersion, 12.5 mmol) was added. After 30 min m-bromobenzenethiol (1.0 mL, 9.7 mmol) was added and the reaction was judged to be complete 30 min later by tlc. The reaction mixture was partitioned between saturated aqueous ammonium chloride and ethyl acetate. The layers were separated and the aqueous layer was extracted with ethyl acetate (3 x, 100 mL). The combined organic extracts were washed (1x, 15% aqueous sodium hydroxide; 2x, brine), dried (Na 2 SO 4 ), filtered and concentrated in vacuo to to ˜400 mL. Decolorizing carbon was added to the organic extracts and the solution was filtered through a celite pad as and concentrated in vacuo to give the unpurified product as an orange solid (19.4 g). The solid was taken up in ether and treated with decolorizing carbon, filtered through celitc, and the volatiles removed in vacuo. Two recrystallizations from ether/hexanes provided pure 3-(p-nitrobenzenethioxy)bromobenzene.
Step 2: 3-(p-aminobenzenethioxy)bromobenzene.
To a THF (15 mL) solution of 3-(p-nitrobenzenethioxy)bromobenzene (2.0 g, 6.4 mmol), prepared as in step 1, was added methanol (50 mL) and CuC 1 (0.89 g, 99%, 9.0 mmol). The solution was cooled to ˜10° C. in an icebath and solid potassium borohydride (1.13 g, 21 mmol) was added in small portions while maintaining the reaction temperature below 20° C. After complete addition of potassium borohydride the icebath was removed. The reaction was judged to be complete after 20 min and was quenched by adding water (40mL) while maintaining the reaction temperature under 20° C. The quenched reaction mixture was filtered through celite and partitioned between ether and water. After separating the layers the aqueous layer was extracted three times with ether. The combined organic layers were washed twice with brine and concentrated to 1/2 the original volume. The solution was treated with decolorizing carbon while drying over MgSO 4 , filtered through a celite pad, and concentrated in vacuo to give 3-(p-aminobenzenethioxy)bromobenzene (1.81 g, 101%) as a waxy red solid which was carried on without further purification.
Step 3: 3-(N-formyl-p-aminobenzenethioxy)bromobenzene.
3-(p-aminobenzenethioxy) bromobenzene (1.13 g, 4.1 mmol), prepared as in step 2 was formylated according to the procedure of Krishnamurthy (Tetrahedron Lett. 1982, 23, 33 15). The reaction mixture was partitioned between ether and saturated aqueous sodium bicarbonate. The layers were separated and the aqueous layer was extracted three times with ether. The combined organic layers were washed once with brine, treated with decolorizing carbon and MgSO 4 , filtered through a celite pad, and concentrated in vacuo to give 3-(N-formyl-p-aminobenzenethioxy)bromobenzene as a light brown oil (1.31 g, 104%) which was carried on without further purification.
Step 4: 3-(N-methyl-p-aminobenzenethioxy)bromobenzene.
A flask equipped with a magnetic stirbar was charged under a stream of nitrogen with freshly dried THF (100 mL) and sodium hydride (2.75 g, 60% oil dispersion, 69 mmol). A solution in dry THF of 3-(N-formyl-p-amino-benzene thioxy)bromobenzene (17.63 g, 57.4 mmol), prepared as in step 3, was added slowly. After foaming ceased dry DMF (100 mL) and methyl iodide (5.75 mL; plug filtered through neutral alumina) were added. The reaction was stirred at ambient temperature for 1.5 hours when the reaction was judged to be complete by tlc. The reaction was quenched with excess saturated aqueous ammonium chloride and partitioned between water and ether. The layers were separated and the aqueous layer was extracted with three times with ether. The combined organic layers were washed twice with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to give the alkylated compound (24.74 g). The resulting residue was dissolved in ethanol (230 mL), 15% aqueous sodium hydroxide was added, and the resulting mixture was heated at 60° C. for 0.5 hours and at 80° C. for 0.5 hours. The reaction mixture was cooled in an icebath and neutralized to pH˜7 with 10% aqueous HCl. The resulting mixture was partitioned between ether and water. The layers were separated and the aqueous layer was extracted with three times with ether. The combined organic layers were washed twice with saturated aqueous NH 4 C 1 , twice with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to give 15.95 g of crude product. Purification by chromatography on silica gel (5% ethyl acetate:hexanes) provided pure 3-(N-methyl-p-aminobenzenethioxy)bromobenzene (12.21 g, 73%).
Step 5: 3-(N-allyl-N-methyl-p-aminobenzenethioxy)bromobenzene.
A flask was charged with potassium hydride (0.3 g, 35% oil dispersion, 2.62 mmol) and dry THF (1.5 mL) under a stream of nitrogen. A solution of 3-(N-methyl-p-aminobenzenethioxy)bromobenzene (0.50 g, 1.71 mmol), prepared as in step 4, in dry THF was added via syringe. When gas evolution ceased, allyl bromide (0.38 mL, 4.27 mmol, passed through a neutral alumina pad before addition) was added in a single portion, followed by dry DMF (3.4 mL). After 15 min the reaction was quenched with isopropanol and partitioned between saturated aqueous NH 4 C 1 and ethyl acetate. The layers were separated and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed twice with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to give 0.91 g of crude product. Purification by chromatography on silica gel (5% ethyl acetate:hexanes) provided pure 3-(N-allyl-N-methyl-p-aminobenzenethioxy)bromobenzene (0.43 g, 75%).
Step 6: (4R, 1'R) and (4R, 1'S)-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)hydroxymethyl]-1,3-dioxolane.
The desired compound was prepared according to the method of Example 1, step 1, except substituting 3-(N-allyl-N-methyl-p-aminobenzenethioxy)bromobenzene for 3-(napth-2-ylmethoxy)-5-fluoro-bromobenzene. The mixture of alcohols was not separated during purification.
Step 7:E- and Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane.
The desired compounds were prepared according to the method of Example 1, steps 2 and 3, except substituting 124R, 1'R) and (4R, 1'S)-4-[(3-(4-(N-allyl-N-methyl phenylthioxyl)phenyl)hydroxymethyl]-1,3-dioxolane (2.02 g, 5.25 mmol), prepared as in step 6, for (4R, 1'R)- and (4R, 1'S)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethoxy)phenyl)hydroxymethyl]-1,3-dioxolane. The oxime isomers (871 mg, 46%) were isolated by chromatography on silica gel (7% ethyl acetate:hexanes). Z-(4S)-O-Methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, which solidified on standing, was recrystallized from cold ether/ethyl acetate mp 49°-50° C. 1 H NMR (300 MHz, CDCl 3 ) δ7.25-7.43 (4H, m), 7.28 (1H, t, J=8 Hz), 7.08 (1H, br d, J=8 Hz 6.72 (2H, br d, J=6 Hz), 5.84 (1H, octet, J=5.5, 14, 17 Hz), 5.42 (1H, t, J=7.5 Hz), 5.18 (1H, br d, J=14 Hz), 5.16 (1H, br d, J=17 Hz), 4.42 (1H, t, J=7.5 Hz), 3.93-3.96 (5H, m), 3.81 (1H, t, J=7.5 Hz), 2.98 (3H, s), 1.34 (3H, s), 1.23 (3H, s). MS m/e 413 (M+H) + . Analysis calc'd for C 23 H 28 N 2 O 3 S: C, 66.96; H, 6.84; N, 6.79. Found: C, 66.91; H, 6.93; N, 6.79. E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3dioxolane was an oil. 1 H NMR (300 MHz, CDCl 3 ) δ7.36 (2H, d, J=8.5 Hz), 7.22 (1H, d, J=7.5 Hz), 7.17 (1H, br s), 7.09 (1H, br t, J=6.5 Hz), 6.75 (2H, br s) 5.87 (1H, octet, J=5.5, 10, 18 Hz), 5.19 (1H, br d, J=10 Hz), 5.17 (1H, br d, J =18 Hz), 4.82 (1H, t, J=7 Hz), 4.18 (1H, dd, J=7, 8.5 Hz), 3.95 (2H, dr, J=5.5, 1,1 Hz), 3.83-3.85 (4H, m), 2.98 (3H, s), 1.37 (3H, s), 1.26 (3H, s). MS m/e 413 (M+H) + . Analysis calc'd for C 23 H 28 N 2 O 3 S: C, 66.96; H, 6.84; N, 6.79. Found: C, 66.98; H, 6.82; N, 6.71.
EXAMPLE 4
Preparation of Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane.
Step 1:Z-(4R)-O-methyl-2,2-dimethyl-4-[(3-(4-N-methylaminophenylthioxy)phenyl)oximinomethyl]-1,3-dioxolane.
To an ethanol (22 mL) solution of Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane (268 mg, 0.65 mmol), prepared as in Example 3, was added tris(triphenylphosphine)ruthenium(II) chloride (120 mg, 0.13 mmol). The resulting solution was heated at 80° C. for 30 min, another portion of the ruthenium catalyst (120 mg, 0.13 mmol) was added, and the reaction was stirred until it cooled to ambient temperature. The volatiles were removed in vacuo and the residue was partitioned between water and ethyl acetate. After separating the layers the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with brine, dried over MgSO 4 , filtered and concentrated in vacuo. The resulting oil was purified by chromatography on silica gel (30% ethyl actetate:hexanes) to provide Z-(4S )-O-methyl-2,2-dimethyl-4- [(3-(4- N-methylaminophenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane (227 mg, 94%). Step 2: Z-(4S)-O-Methyl-2,2-dimethyl-4-[(3-(4-(N',N' -dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane.
To a solution of Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-N-methylaminophenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane (100 mg, 0.27 mmol), prepared as in step 1, in dry THF at -78° C. was added lithium hexamethyldisilazide (LiHMDS, 403 μL, 1M solution in THF, 0.40 mmol ). After stirring in the cold for 10 min dimethylcarbamoyl chloride (37μL, 0.40 mmol) was added via syringe in a single portion. The cooling bath was removed and the reaction mixture was stirred for 30 min at ambient temperature. The reaction was quenched by adding excess water and partitioning the resulting mixture between saturated aqueous NH 4 Cl and ethyl acetate. After separating the layers, the aqueous layer was extracted 3 times with ethyl acetate. The combined organic layers were washed with brine, dried over MgSO 4 , filtered and concentrated in vacuo. The resulting oil was purified by chromatography on silica gel (50% ethyl actetate:hexanes) to provide Z-(4S)-O-methyl-4-[(3-{4-(N',N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]- 1,3-dioxolane as an oil which crystallized upon dissolving in ethyl acetate and cooling (58 mg, 44%). mp 102°-103° C. 1 H NMR (300 MHz, CDCl 3 ) δ7.52 (1H, m), 7.37-7.43 (1H, m), 7.26-7.33 (4H, m), 6.98 (2H, d, J=8 Hz), 5.44 (1H, t, J=7.5 Hz), 4.44 (1H, dd, J=7.5, 8.5 Hz), 3.95 (3H, s), 3.82 (1H, dd, J=7.5, 8.5 Hz), 3.21 (3H, s), 2.72 (6H, s 1.34 (3H, s), 1.23 (3H, s). MS m/e 444 (M+H) + , 461 (M+NH 4 ) + . Analysis calc'd for C 23 H 29 N 3 O 4 S: C, 62.28; H, 6.59; N, 9.47. Found: C, 62.18; H, 6.71; N, 9.23.
EXAMPLE 5
Preparation of E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N',N': dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3: dioxolane.
The desired compound was prepared as described in Example 4 except substituting E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane (290 mg, 0.70 mmol) for Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane. Purification by chromatography on silica gel (50% ethyl acetate:hexanes) provided E-(4S)-O-methyl2,2-dimethyl-4- [(3-(4-(N', N'-dimethylaminocarbonyl-No methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane (121 rag, 58%) as an oil. 1H NMR (300 MHz, CDCl 3 ) t) 7.22-7.38 (6H, m), 6.98 (2H, d, J=8 Hz), 4.84 (1H, t, J=7.5 Hz), 4.13 (1H, dd, J=7.5, 8.5 Hz), 3.87 (1H, dd, J=7.5, 8. Hz), 3.84 (3H, s), 3.22 (3H, s), 2.72 (6H, s), 1.38 (3H, s), 1.25 (3H, s). MS m/e 444 (M+H) + , 46 1 (M+NH 4 ) + . Analysis calc'd for C 23 H 29 N 3 O 4 S: C, 62.28; H, 6.59; N, 9.47. Found: C, 61.91; H, 6.68; N, 9.15.
EXAMPLE 6
Preparation of Z- and E-(4R)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)oximinomethyl]-1,3-dioxolane.
Step 1: (S) -(-)2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde.
The desired compound was prepared as described in Jackson, Synthetic Commun. 1988, 18(4), 337-341), except starting with L-(S)-glyceraldehyde, prepared as described by Hubschwerlen, C. Synthesis, 1986, 962-964, instead of D-(R)-glyceraldehyde.
Step2: Z-(4R)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinoethyl[-1,3-dioxolane.
The desired compounds are prepared according to the method of Example 1, steps 1-3, except substituting (S)-(-)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde, prepared as in step 1, for (R)-(-)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde, and substituting 3-(N-allyl-N-methyl-p-aminobenzenethioxy)bromobenzene, prepared as in Example 3, step 5, for 3-(napth-2-ylmethoxy)-5-fluoro-bromobenzene.
EXAMPLE 7
Preparation of Z- and E-(4R)-O-methyl-2,2-dimethyl-4-[(3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl}phenyl)oximinomethyl]-1,3-dioxolane.
The desired compounds are prepared according to the method of Example 4, except substituting Z- and E-(4R)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, prepared as in Example 6, for Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane.
EXAMPLE 8
Preparation of E-(4R)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3dioxolane.
The desired compound was prepared according to the method of Example 1, except substituting (S)-(-)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde, prepared as in Example 6, step 1, for (R)-(-)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde. 1 H NMR (300 MHz, CDCl 3 ) δ7.37 (2H, d, J=9 Hz), 7.39 (2H, d, J=9 Hz), 6.81 (1H, br s), 6.67-6.77 (2H, m), 4.98 (2H, s), 4.86 (1H, t, J=7.5 Hz), 4.13 (2H, dd, J=8.5, 7.5 Hz), 3.92 (1H, dd, J=8.5, 7.5 Hz), 3.87 (3H, s), 3.23 (3H, s), 2.71 (6H, s), 1.39 (3H, s), 1.32 (3H, s). MS m/e 460 (M+H) + , 477 (M+NH 4 ). Analysis calc'd for C 24 H.sub. 30 N 3 O 5 F: C, 62.73; H, 6.58; N, 9.14. Found: C, 65.28; H, 5.83; N, 6.12 .
EXAMPLE 9
Preparation of E- and Z-(4S)-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane.
The desired compounds are prepared according to the method of Example 1, steps 2 and 3, except substituting 3-(N-allyl-N-methyl-p-aminobenzenethioxy)bromobenzene, prepared as in Example 3, step 5, for 5-fluoro-3-(napth-2-ylmethoxy)bromobenzene, and substituting hydroxylamine hydrochloride for O-methylhydroxylamine hydrochloride.
EXAMPLE 10
Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylsulfinyl)phenyl)oximino -1,3-dioxolane.
The desired compounds are prepared by oxidation of Z- and E-(4S)-O-methyl-4-2,2-dimethyl-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, prepared as in Example 3, with sodium metaperiodate as described in EPA 409 413 (Example 7).
EXAMPLE 11
Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylsulfonyl)phenyl)oximinomethyl]-1,3-dioxolane.
The desired compounds are prepared by oxidation of Z- and E-(4S)-O-methyl4-2,2-dimethyl- [(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, prepared as in Example 3, with potassium peroxymonosulfate as described in EPA 409 413 (Example 14).
EXAMPLE 12
Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N',N'-dimethylaminothiocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]1,3-dioxolane.
The desired compound is prepared by treatment of Z- and E-(4S)-O-methyl-4-2,2-dimethyl- [(3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, prepared as in Examples 4 and 5, with Lawesson's Reagent ([2,4-bis-(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide) according to the method of Katah, A., Kashima, C., and Omote, Y., Heterocycles, 1982, 19 (12), 2283.
EXAMPLE 13
Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-(5-fluoro-3-(4-((N',N'-dimethylaminocarbonyl)-N-methylamino)benzylthioxy)phenyl)oximinomethyl]-1,3-dioxolane.
Step 1: Z- and E-(4S)-O-methyl-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(benzylthioxy)phenyl)oximinomethyl]-1,3-dioxolane.
The desired compounds are prepared according to the method of Example 1, steps 1-3, except substituting 5-fluoro-3-benzylthiobromobenzene, prepared as described in EPA 420 511 (Example 4), for 3-(napth-2-ylmethyloxy)-5-fluorobromobenzene.
Step 2: Z- and E-(4S)-O-methyl-2,2-dimethyl-4-1(5-fluoro-3-mercaptophenyl)oximinomethyl]-1,3-dioxolane.
The desired compounds are prepared by debenzylation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(benzylthioxy)phenyl)oximinomethyl]-1,3-dioxolane, prepared in step 1, with benzoyl peroxide as described in EPA 420 511 (Example 4).
Step 3: Z- and E-(4R)-O-methyl-2,2-dimethyl-4-(5-fluoro-3-(4-((N',N'-dimethylaminocarbonyl)-N-methylamino)benzylthioxy)phenyl)oximinomethyl]-1,3-dioxolane.
The desired compounds are prepared according to the method of Example 1, step 9, except substituting Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-mercaptophenyl)oximinomethyl -1,3-dioxolane, prepared as in step 2, for E-(4S)-O-methyl-2,2-dimethyl-[(5-fluoro-3-hydroxyphen-1-yl)oximinomethyl]-1,3-dioxolane.
EXAMPLE 14
Preparation of anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino) 1-1,2,3-trimethoxypropane.
Step 1: (4R, 1'-R)- and (4R, 1'S):2,2-dimethyl-4,2,2-dimethyl-[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)hydroxymethyl]-1,3-dioxolane.
A flame-dried flask was charged with 3-(napth-2-ylmethyloxy)-5-fluorobromobenzene (0.86 g. 2.6 mmol), prepared according to the method of EPA 385 679, a stir bar, and freshly dried tetrahydrofuran (THF, 23 mL). The resulting solution was cooled to -78° C. under a nitrogen atmosphere andn-butyllithium (2.5M in hexanes, 1.04 mL, 2.6 mmol) was added slowly in a dropwise fashion via syringe. After stirring for 10 minutes at -78° C. a THF solution (6 mL) of (R)-(+)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde (0.34 g, 2.6 mmol), prepared as described in Jackson, Synthetic Commun. 1988, 18(4), 337-341) was added. The resulting solution was stirred for 30 minutes at -78° C., and the cooling bath was removed. The reaction was stirred for 1 hour and then quenched with excess saturated aqueous NH 4 Cl. The mixture was partitioned between saturated aqueous NH 4 Cl and ethyl acetate. The organic layer was washed twice with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to provide a cloudy oil which was purified by chromatography on silica gel (20% ether:hexanes) to give the less polar anti-(4R, 1'S) alcohol (0.193 g, 20%), a mixture of both isomers (0.233 g, 23%), and the more polar syn-(4R, I'R) alcohol (0.149 g, 15%).
Step 2: syn-(4R, 1'R)- and anti-(4R, 1'S)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)methyloxymethyl[-1,3-dioxolane.
Each alcohol isomer prepared in step 1 was independently methylated following the procedure described for the anti-isomer. A flask was charged with anhydrous DMF (5 mL) and(4R, 1'S)-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)hydroxymethyl]-1,3-dioxolane (0.185 g, 0.484 mmol). Sodium hydride (80% oil dispersion, 14.5 mg, 0.484 mmol) was added in a single portion and the reaction mixture was stirred at ambient temperature until gas evolution ceased (5-10 minutes). To the resulting solution was added methyl iodide (103 μL, 0.726 mmol; freshly filtered through a neutral alumina pad) and the reaction mixture was stirred at ambient temperature for 0.5 hours. The reaction was quenched by adding water and was then partitioned between water and ethyl acetate. The organic layer was washed twice with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to provide a yellow oil which was purified by chromatography on silica gel (50% ether:hexanes) to give anti-(4R, 1'S)-2,2 -dimethyl-4-2,2-dimethyl[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)methyloxymethyl ]-1,3-dioxolane (0.176 g, 92%) as a colorless oil. 1 H NMR (300 MHz, CDCl 3 ) 6 7.83-7.90 (4H, m), 7.47-7.55 (3H, m), 6.79 (1H, br s), 6.63-6.72 (2H, m), 5.22 (2H, s), ca. 4.12 (1H, m), 4.0-4.05 (3H, m), 3.35 (3H, s), 1.41 (3H, s), 1.29 (3H, s). MS m/e 397 (M+H) + , 414 (M+NH 4 ) + . Analysis calc'd for C 24 H 25 O 4 F(0.1 H 2 O): C, 72.38; H, 6.38. Found: C, 72.14; H, 6.05.
Methylation of (4R, 1'R)-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(napth-2as ylmethyloxy)phenyl)hydroxymethyl]-1,3-dioxolane as described above gave syn(4R, 1'R)-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)methyloxymethyl] -1,3-dioxolane. 1 H NMR (300 MHz, CDCl 3 ) δ7.83-7.90 (4H, m), 7.47-7.55 (3H, m), 6.78 (1H, br s), 6.63-6.72 (2H, m), 5.22 (2H, s), 4.24 (1H, quartet, J=7.5 Hz), 4.08 (1 H, d, J=7.5 Hz), 3.60 (1H, dd, J=8.5, 7.5 Hz), 3.52 (1H, dd, J=8.0, 7.5 Hz), 3.25 (3H, s), 1.42 (3H, s), 1.37 (3H, s). MS m/e 397 (M+H) + , 414 (M+NH 4 ) + . Analysis calc'd for C 24 H 25 O 4 F(0.75 H 2 O): C, 70.31; H, 6.15. Found: C, 70.31; H, 5.94.
Step 3: anti-(1S, 2R)-2,3-dihydroxy-1-methyloxymethyl-1-(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)propane.
To a solution of anti-(4R, 1'S)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2ylmethyloxy)phenyl)methyloxymethyl]-1,3-dioxolane (0.145 g, 0.37 mmol), prepared as in step 2, dissolved in methanol (10 mL) was added catalytic paratoluenesulfonic acid monohydrate (25 mg, 0.13 mmol). The reaction was stirred at ambient temperature until TLC indicated complete reaction (˜18 hours). The is volatiles were removed in vacuo and the resulting solution was partitioned between ethyl acetate and saturated aqueous NaHCO 3 . The organic phase was washed twice with brine, dried over MgSO 4 , filtered and concentrated in vacuo to provide anti-(1 S, 2R) 2,3-dihydroxy-1-methyloxymethyl-1 -(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)propane as a colorless solid (120 mg, 92%) which was carried on without further purification.
Step 4: anti-(1S, 2R)-1-[(5-fluoro-3-(napth-2-ylmethyloxy)-1,2,3-trimethoxypropane.
To a solution in dry THF (5 mL) of anti-(1S, 2R)-2,3-dihydroxy-1 -[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)]-1-methoxypropane (50 mg, 0.14 mmol), prepared as in Example 2, step 1, was added sodium hydride (8.4 mg; 80% oil dispersion; 0.28 mmol) was. After gas evolution ceased, methyl iodide (17 μL; 0.28 mmol) was added and the reaction was stirred at ambient temperature for 15 hours. Excess sodium hydride was quenched by careful addition of water. The reaction was partitioned between water and ethyl acetate. The aqueous layer was extracted twice with ethyl acetate. The combined organic layers were washed with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to provide an orange oil. Purification by slica gel chromatography (ethyl acetate/hexanes) provided pure anti-(1 S, 2R)-1-[(5-fluoro-3-((napth-2-yl)methoxy)-phenyl) ]-1,2,3-trimethoxypropane (40 mg, 74% ). 1l H NMR (300 MHz, CDCl 3 ) δ 7.83-7.90 (4H, m), 7.47-7.55 (3H, m), 6.82 (1H, br s), 6.65-6.72 (2H, m), 5.22 (2H, s), 4.21 (1H, d, J=6 Hz), 3.47-3.53 (2H, m), 3.34-3.42 (1H, m), 3.34 (3H, s), 3.27 (3H, s), 3.25 (3H, s). MS m/e 402 (M+NH 4 ) + . Analysis calc'd for C 23 H 25 O 4 F: C, 71.86; H, 6.55. Found: C, 71.61; H, 6.52.
Step 5: anti-(1S, 2R)-1-[(5-fluoro-3-hydroxyphenyl)]-1,2,3-trimethoxypropane.
The desired compound was prepared according to the method of Example 1, step 4, except substituting anti-(IS, 2R)-1-[(5-fluoro-3-((napth-2-yl)methoxy)phenyl)]-1,2,3-trimethoxypropane, prepared as in step 4, for E-(4S)-O-methyl-2,2dimethyl -4-2,2-dimethyl-[(5-fluoro-3-(napth-2-ylmethoxy)phenyl)oximinomethyl ]-1,3-dioxolane.
Step 6: anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)-benzyloxy)phenyl)]-1,2,3-trimethoxypropane.
The desired compound was prepared according to the method of Example 1, step 9, except substituting anti-(1S, 2R)-1-[(5-fluoro-3-hydroxyphenyl)]-1,2,3-trimethoxypropane, prepared as in step 5, for E-(4S)-O-methyl-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-hydroxyphen-1-yl)oximinomethyl ]-1,3-dioxolane. Purification by chromatography on silica gel (50% ethyl acetate:hexanes) provided anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)]-1,2,3-trimethoxypropane. 1 H NMR (300 MHz, CDCl 3 ) δ7.48 (2H, d, J=9 Hz), 7.07 (2H, d, J=9 Hz), 6.87 (1H, br s), 6.69 (1H, br d, J=9.5 Hz), 6.62 (1H, dr, J=10.5, 3 Hz), 5.01 (2H, s), 4.20 (1H, d, J =6 Hz), 3.48-3.52 (2H, m), 3.37-3.42 (1H, m), 3.37 (3H, s), 3.27 (3H, s) (3H, s), 3.22 (3H, s). MS m/e 435 (M+H) + , 452 (M+NH 4 ). Analysis calc'd for C 23 H 31 N 2 O 5 F: C, 63.57; H, 7.19; N, 6.44. Found: C, 63.41; H, 7.28; N, 6.28.
EXAMPLE 15
Preparation of anti-(1S, 2R)-1-[(5-fluoro-3-{4-(N-acetyl-N-methylamino): benzyloxy)phenyl)]-1,2,3-trimethoxypropane.
The desired compound (yellow oil, 154 mg, 91%), was prepared according to the method of Example 2, step 4, except substituting anti-(1S, 2R)-1-[(5-fluoro-3-hydroxyphenyl)]-1,2,3-trimethoxypropane, prepared as in Example 8, step 5, for E-(4S)-O-methyl-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-hydroxyphenyl)oximinomethyl]-1,3-dioxolane. 1H NMR (300 MHz, CDCl 3 ) δ7.49 (2H, d, J=9 Hz), 7.22 (2H, d, J=9 Hz), 6.79 (1H, br s), 6.72 (1H, br d, J=9.5 Hz), 6.64 (1H, dr, J=10.5, 3 Hz), 5.07 (2H, s); 4.21 (1H, d, J=6 Hz), 3.49-3.53 (2 3.37-3.42 (1H, m), 3.37 (3H, s), 3.28 (6H, s), 3.26 (3H, s), 1.89 (3H, br s) m/e 406 (M+H) + , 423 (M+NH 4 ) + . Analysis calc'd for C 22 H 28 NO 5 F: C, 65.17; H, 6.96; N, 3.45. Found: C, 65.17; H, 7.09; N, 3.27.
EXAMPLE 16
Preparation of anti-(1S, 2R)-1-[3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl]: 1,2,3 -trimethoxypropane.
The desired compound is prepared according to the method of Example 14, steps 2-4, except substituting (4R, 1'R) and (4R, 1'S)-2,2-dimethyl-4-[(3-(4-(N allyl-N-methylamino)phenylthioxyl)phenyl)hydroxymethyl]-1,3-dioxolane, prepared as in Example 3, step 6, for (4R, 1'S)-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)hydroxymethyl]-1,3-dioxolane.
EXAMPLE 17
Preparation of anti-(1S, 2R)-1-[3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl) phenyl]-1,2,3-trimethoxypropane.
The desired compound is prepared according to the method of Example 4, except substituting anti-(1S, 2R)-1-[3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane, prepared as in Example 15, for Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane.
EXAMPLE 18
Preparation of anti-(1S, 2R)-1-[5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzylthioxyl)phenyl]-1,2,3-trimethoxypropane.
Step 1: anti-(1S, 2R)-1-[(5-fluoro-3-(benzylthioxy)phenyl-1,2,3: trimethoxypropane.
The desired compound is prepared according to the method of Example 14, steps 1-4, except substituting 5-fluoro-3-benzylthiobromobenzene, prepared as described in EPA 420 511 (Example 4), for 3-(napth-2-ylmethyloxy)-5-fluorobromobenzene.
Step 2: anti-(1S, 2R)-1-[(5-fluoro-3-mercaptophenyl) ]-1,2,3-trimethoxypropane.
The desired compound is prepared according to the method of Example 13, step 2, except substituting anti-(1S, 2R)-1-[(5-fluoro-3-(benzylthioxy)phenyl)]- 1,2,3-trimethoxypropane, prepared as in step 1, for Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(benzylthioxy)phenyl)oximinomethyl ]-1,3-dioxolane.
Step 3: anti-(1S, 2R)-1-[5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino) benzylthioxyl)phenyl]-1,2,3-trimethoxypropane.
The desired compound is prepared according to the method of Example 14, step 6, except substituting anti-(1S, 2R)-1-[(5-fluoro-3-mercaptophenyl)]-1,2,3trimethoxypropane prepared as in step 2, for anti-(1S, 2R)-1-[(5-fluoro-3-hydroxyphenyl) ]-1,2,3-trimethoxypropane.
EXAMPLE 19
Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-((4-(N', N'-dimethylaminocarbonyl-N-methylamino)methyl)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane.
Step 1: Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4: bromomethyl)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane.
The desired compounds are prepared according to the method of Example 1, step 9, except substituting α,α'-dibromo-p-xylene for 4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyl chloride.
Step 2: Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-((4-(N', N'dimethylaminocarbonylamino)methyl)benzyloxy)phenyl)oximinomethyl ]-1,3-dioxolane.
The desired compounds are prepared by reaction of a solution of 1,1-dimethylurea in DMF with NaH and Z- and E-(4S)-O-methyl-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(4-bromomethyl)benzyloxy)phenyl)oximinomethyl ]-1,3-dioxolane, which is prepared as described in step 1.
Step 3: Z- and E-(4S)-O-methyl.-.2.2-dimethyl-4-[(5-fluoro-3-((4-(N', N': a0 dimethylaminocarbonyl-N-methylamino)methyl)benzyloxy)phenyl)oximinomethyl]: 1,3-dioxolane.
The desired compounds are prepared according to the method of Example 14, step 2, except substituting Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-((4(N', N'-dimethylaminocarbonylamino)methyl)benzyloxy)phenyl )oximinomethyl ]-1,3-dioxolane, prepared as in step 2, for (4R, 1'S)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethyloxy) phenyl)hydroxymethyl]-1,3-dioxolane.
EXAMPLE 20
Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-((4-imidazolidin-2-on-1-ylmethyl)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane.
The desired compounds are prepared according to the method of Example 19, step 2, except substituting 2-imidazolidinone for 1,1-dimethylurea.
EXAMPLE 21
Preparation of Z- and E-(IS)-O-methyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]]-1,2-dimethoxyethane.
The desired compounds are prepared according to the method of Example 14, steps 3 and 4, except substituting Z- and E-(4S)-O-Methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, prepared as in Example 3, for anti-(4R, 1'S)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)m -1,3-dioxolane.
EXAMPLE 22
Preparation of Z- and E-(1S)-O-methyl-4-[(3(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,2-dimethoxyethane.
The desired compounds are prepared according to the method of Example 4, except substituting Z- and E-(1S)-O-methyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]]-1,2-dimethoxyethane, prepared as in Example 21, for Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane.
EXAMPLE 23
Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-acetyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane.
The desired compounds are prepared according to the method of Example 1, step 9, except substituting acetyl chloride for N, N-dimethylcarbamoyl chloride.
EXAMPLE 24
Preparation of E- and Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-allyl-N-methylamino)phenylthioxyl) 1,3-dioxolane.
The desired compounds are prepared according to the method of Example 3, except substituting 5-fluoro-3-bromobenzenethiol, prepared according to the method described in EPA 420 511 (Example 4), for m-bromobenzenethiol.
EXAMPLE 25
Preparation of E- and Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3: dioxolane.
The desired compounds are prepared according to the method of Example 4, except substituting Z-(4S)-O-methyl-2,2-dimethyl-4-[(5- fluoro-3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, prepared as in Example 24, for Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenyl thioxyl )phenyl)oximinomethyl ]-1,3-dioxolane.
EXAMPLE 26
Preparation of anti-(1S, 2R)-1- [5-fluoro-3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane.
The desired compound is prepared according to the method of Example 16, except substituting (4R, 1'R) and (4R, 1'S)-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)hydroxymethyl]-1,3-dioxolane, prepared as in Example 24, for (4R, 1'S)-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(napth-2-ylmethyloxy -1,3-dioxolane.
EXAMPLE 27
Preparation of anti-(1 S, 2R)-1-[5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane.
The desired compound is prepared according to the method of Example 17, except substituting anti-(1S, 2R)-1-[5-fluoro-3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane, prepared as in Example 26, for anti-(1S, 2R)-1-[3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane.
EXAMPLE 28
Preparation of E- and Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-methylpiperazin-1-ylcarbonyl)-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane.
The desired compounds are prepared by treatment of E- and Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-N-methylaminophenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, prepared as in Example 4, step 1, with triphosgene and 4-methylpiperazine according to the method of Eckert, H., and Forster, B., Angew. Chem. lnt. Ed., 1987, 26(9), 894-895.
Example 29
Preparation of anti-(1S, 2R)-1-[3-(4-(N-(4- methylpiperazin-1-ylcarbonyl)-N-methylamino) phenylthioxyl)phenyl]-1,2,3-trimethoxypropane.
The desired compound is prepared according to the method of Example 28, except substituting anti-(1S, 2R)-1-[3-(4-(N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane, prepared as in Example 16, for E- and Z-(4S)-O-methyl2,2-dimethyl-4-[(3-(4-N-methylaminophenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane.
The compounds represented in Table 2 are prepared as described in Schemes 4 and 5 and Example 28.
TABLE 2______________________________________Novel 1,3-dioxolane inhibitors of 5-Lipoxygenase. ##STR24##Example R.sup.5 R.sup.1 R.sup.9 R.sup.10______________________________________30 H Me Me ##STR25##31 F Me Me ##STR26##32 H Me Me ##STR27##33 F Me Me ##STR28##34 H Me Me ##STR29##35 F Me Me ##STR30##36 H Me Me ##STR31##37 F Me Me ##STR32##38 H Me Me ##STR33##39 F Me Me ##STR34##40 H Me Me ##STR35##41 F Me Me ##STR36##42 H Me ##STR37##43 F Me ##STR38##44 H Me ##STR39##45 F Me ##STR40##46 H Me ##STR41##47 F Me ##STR42##______________________________________
The compounds represented in Table 3 are prepared as described in Schemes 4 and 5 and Example 29.
TABLE 3______________________________________Novel Trimethoxypropane inhibitors of 5-Lipoxygenase. ##STR43##Example R.sup.5 R.sup.1 R.sup.9 R.sup.10______________________________________48 H Me Me ##STR44##49 F Me Me ##STR45##50 H Me Me ##STR46##51 F Me Me ##STR47##52 H Me Me ##STR48##53 F Me Me ##STR49##54 H Me Me ##STR50##55 F Me Me ##STR51##56 H Me Me ##STR52##57 F Me Me ##STR53##58 H Me Me ##STR54##59 F Me Me ##STR55##60 H Me ##STR56##61 F Me ##STR57##62 H Me ##STR58##63 F Me ##STR59##64 H Me ##STR60##65 F Me ##STR61##______________________________________ | Compounds of the structure ##STR1## where R 1 is alkyl of one to four carbon atoms and R 2 is selected from
(a) alkenyl of one to four carbon atoms,
(b) ##STR2## (c) ##STR3## and (d) ##STR4## are potent inhibitors of lipoxygenase enzymes and thus inhibit the biosynthesis of leukotrienes. These compounds are useful in the treatment or amelioration of allergic and inflammatory disease states. | 2 |
FIELD OF THE INVENTION
[0001] This invention relates generally to method and apparatus for positioning an optical fiber. More particularly, this invention relates to a method and apparatus for positioning an optical fiber in a passageway formed through a ferrule of an optical fiber connector in such a way as to compensate for eccentricity of the passageway relative to the longitudinal axis of the ferrule such that the optical fiber position relative to the passageway is substantially straight for a predetermined distance.
BACKGROUND OF THE INVENTION
[0002] The transmission of communication signals for voice, video, data, and the like, is increasingly accomplished using optical fibers because of the high bandwidth and throughput capabilities they offer in comparison with conventional electrical conductors. Unlike connections for electrical conductors, however, the fiber optic connections must be executed with great care and precision in order to minimize losses in the transmitted signal. As is known in the art, two optical fibers are connected by bringing the end faces of the optical fibers into coaxial alignment such that the optical fiber end faces abut or are separated by only a slight distance. In this way, the two optical fibers form a substantially continuous waveguide to transmit signals. Typically, each optical fiber is mounted in a passageway (e.g., a bore, channel, groove, or any other similar structure) formed through a ferrule, which may be a cylindrical or non-cylindrical shaped body made of material, such as, ceramic or plastic.
[0003] The ferrule is usually mounted in a body of an optical fiber connector that is configured to mate with another connector also having a ferrule mounted therein. The connectors are configured so as to coaxially align the ferrules and the optical fibers therein. For example, an SC ferrule may be configured such that the bore in each ferrule is nominally centered, relative to the outer surface thereof.
[0004] The degree of precision with which the optical fibers are aligned with each other affects the performance of the connection between two optical fibers. Several factors can affect the loss or attenuation of signal caused by the connection including: (1) lateral displacement of the mating end faces of the optical fibers, that is, the lateral distance between the two axes of the optical fibers at the mating end faces thereof; (2) angular misalignment of the optical fibers; and (3) axial separation between the end faces of the optical fibers. Other factors that can affect the loss or attenuation of signal at a fiber-to-fiber interconnection include: index of refraction mismatch, mode field radius mismatch, the shape and finish of the end faces, and physical damage that may be present at the end faces.
[0005] Of these factors, lateral displacement and angular misalignment have significant impact on the signal attenuation. Lateral displacement or offset of the optical fibers of two mated connectors can result from various causes. Two important causes are: (1) eccentricity of the passageway of the ferrule relative to the ferrule's outer surface; and (2) offset of the optical fiber within the passageway. With regard to the latter, the passageway in the ferrule typically is slightly larger in diameter than the optical fiber, and hence, until the optical fiber is fixed in position in the passageway via an adhesive, the optical fiber is free to move in the passageway. Accordingly, the eccentricity of the optical fiber relative to the ferrule can be higher or lower depending on where the optical fiber is secured in the passageway.
[0006] It is known to take advantage of this ability of the optical fiber to move in the passageway so as to minimize the eccentricity of the optical fiber in a ferrule whose passageway is not perfectly centered or aligned in the ferrule. In general, even when care is taken to try to form the passageway in the exact locations of the ferrule (e.g., center of the ferrule), the passageway is usually offset from the central axis of the ferrule to some extent. The offset, or eccentricity, of the passageway is generally characterized by two parameters, the magnitude of the offset and the direction of the offset, both parameters being measured at the end face of the ferrule.
[0007] For example, the eccentricity of a ferrule having a central bore may have a magnitude of 1 μm and this offset may be in the direction of a radial line that can be designated as the 0° position. As noted above, it is known to minimize the eccentricity of an optical fiber disposed in an eccentric passageway by positioning the optical fiber in a particular direction in the passageway. Thus, for instance, in the example given above, the optical fiber can be positioned to one side of the passageway in the direction of a radial line that is displaced 180° from the radial line along which the passageway is offset. In this manner, the eccentricity of the optical fiber, which would be 1 μm if the optical fiber were exactly centered in the passageway, is reduced by half the difference between the diameter of the passageway and the diameter of the optical fiber. Thus, assuming for illustrative purposes that the passageway has a diameter of 126 μm and the optical fiber has a diameter of 125 μm, the eccentricity of the optical fiber can be as low as 0.5 μm if the optical fiber is positioned to the side of the passageway in the opposite direction to that in which the passageway is offset. In contrast, if the optical fiber were positioned to the side of the passageway in the same direction to that in which the passageway is offset, then the optical fiber eccentricity would be 1.5 μm.
[0008] U.S. Pat. No. 4,880,291 discloses an apparatus and method for positioning an optical fiber within a passageway of a ferrule in a predetermined orientation with respect to the direction of eccentricity of the passageway relative to the longitudinal axis of the ferrule. The apparatus has a plurality of receptacles or nests for receiving a plurality of connector bodies each having a ferrule with an optical fiber inserted in a bore thereof. The ferrule in each connector body is rotationally oriented such that the direction of eccentricity of the bore in the ferrule is diametrically opposite to the direction of a protruding tab formed on the outer surface of the connector body. Each nest in the apparatus has a keyway for mating with the tab on the connector body, such that the connector body is oriented in a known manner in the nest. The apparatus includes a plurality of wire-like bails that press against the optical fibers projecting from the ferrules so as to force the optical fibers to the side of the bores in the direction of the tabs on the connector bodies, thus minimizing the optical fiber eccentricity. An adhesive in the bores is then cured to fix the optical fibers in place.
[0009] Although a general method of pushing an optical fiber to one side of the passageway is thus known, the prior art does not provide any guidance on how best to accomplish the method. In practice, it has been found that pushing an optical fiber to a preferred position, such as, to one side of the passageway, can improve the eccentricity of the optical fiber at the end face of the ferrule. However, as illustrated in FIG. 1, which is shown in exaggerated detail for illustrative purposes, the force exerted on the optical fiber to push it to one side of the passageway can cause the optical fiber to bend or bow. When the end of the optical fiber is cut off and the end faces of the optical fiber and ferrule are polished, the optical fiber and ferrule material are removed for some axial distance back from the original end face of the ferrule, as illustrated in FIG. 1 by the broken line representing the position of the end face of the ferrule and optical fiber after polishing. As a result, the optical fiber position relative to the passageway after polishing can differ appreciably from the optical fiber position prior to polishing. In addition, attenuation is caused by the angular misalignment of the mating passageways. As illustrated in FIG. 1, due to the fiber bend, an angular misalignment of the optical fiber axis relative to the ferrule axis exists.
[0010] Thus, a need exists for a method and apparatus for positioning an optical fiber in a passageway to compensate for eccentricity of the passageway relative to the longitudinal centroidal axis of the ferrule such that the optical fiber position relative to the passageway is substantially straight for a distance back from the ferrule end face that is at least as great as the distance representing the maximum length of material that will be removed during polishing.
SUMMARY OF THE INVENTION
[0011] This invention addresses the above needs by providing a optical fiber positioning apparatus and method that reduces the amount of optical fiber bending caused when an optical fiber is pushed in a particular direction in the passageway. Consequently, the position of the optical fiber is substantially straight for an appreciable distance back from the end face of the ferrule so that the optical fiber is still in the desired position in the passageway even after polishing of the optical fiber and ferrule. As used herein, the term “passageway” includes encapsulated passageways (e.g., bores and similar structures), non-encapsulated passageways (e.g., channels, grooves, and similar structures), and combinations thereof. As used herein, the term “ferrule” includes cylindrical and non-cylindrical ferrules housing a single fiber, such as, for example, SC, LC, MU, BLC and other similar ferrules.
[0012] In accordance with one embodiment, a method of positioning an optical fiber in a passageway of a ferrule involves applying a fluid adhesive in the passageway of the ferrule, and subsequently inserting an optical fiber into the passageway of the ferrule such that an end portion of the optical fiber projects out from the passageway beyond the end face of the ferrule, the optical fiber having a diameter less than that of the passageway. A force F is imposed on the end portion of the optical fiber projecting from the ferrule, in a direction generally orthogonal to the longitudinal axis of the passageway, the force having sufficient magnitude to overcome viscosity of the fluid adhesive and to position the optical fiber in the passageway as to compensate for eccentricity of the passageway such that the optical fiber position relative to the passageway is substantially straight for a predetermined distance. In contrast to prior methods, bowing of the optical fiber in the passageway is minimized by imposing the force F at a distance D from the end face such that the resulting moment (F·D) exerted on the optical fiber maintains the axis of the optical fiber straight within at least about 0.025 μm for a distance of at least about 100 μm from the end face into the passageway. Accordingly, up to about 100 μm of material (ferrule, optical fiber, and adhesive) can be removed during polishing and yet the optical fiber position after polishing will be within at least about 0.025 μm of the same position before polishing.
[0013] In an embodiment, the force is imposed on the optical fiber by orienting the optical fiber generally horizontally and hanging a weight on the end portion of the optical fiber projecting out of a passageway. The weight preferably is located on the optical fiber at a distance of at least about 0.5 mm from the end face of the ferrule, more preferably about 0.5 to 1.0 mm, and weighs about 0.1 to 5.0 grams, more preferably about 0.3 to 0.5 grams.
[0014] In an embodiment, an apparatus for positioning an optical fiber includes a fixture defining at least one receptacle, and preferably a plurality of receptacles, each for receiving and holding a ferrule having an optical fiber extending therefrom. The apparatus includes a weight for each receptacle in the holder, each weight being configured to rest on an end portion of the optical fiber projecting from the ferrule in the corresponding receptacle so as to impose a downward force on the optical fiber. A weight positioning mechanism of the apparatus is structured and arranged to lower each weight from a raised position disengaged from the corresponding optical fiber to a lowered position resting on the optical fiber. The entire apparatus can be placed in an oven to cure the adhesive in the passageways of the ferrules. In alternative embodiments, the adhesive may be cured by other suitable curing techniques, such as, for example, UV and the like.
[0015] In an embodiment, a new curing method and apparatus directs a low energy beam of laser radiation at the end portion of the optical fiber extending from the end face of the ferrule. The low energy beam heats the end portion of the fiber and heat conducts along the fiber extending into the passageway. As the heat conducts along the fiber extending into the passageway, the adhesive is cured under the heat impact. Thereafter, a high energy laser beam may cut the optical fiber flush with the adhesive. Alternatively, the optical fiber may be cut during polishing of the end face of the ferrule.
[0016] In an embodiment, the force for pushing the optical fiber to a desired position, such as, to one side of the passageway, is imposed by directing a pressurized fluid, preferably air, against the optical fiber in a direction generally orthogonal to the longitudinal axis of the passageway. The air preferably impacts the optical fiber at a location in close proximity to the end face of the ferrule. Alternatively, the pressurized fluid may impact the optical fiber at a plurality of locations along the optical fiber axis. Once the optical fiber has been positioned, the optical fiber is secured in place by curing the adhesive.
[0017] In a preferred embodiment, a beam of laser radiation is impinged on the end face to heat the adhesive and to, thereby, at least partially cure the adhesive in the portion of the passageway adjacent the end face, thus tacking the optical fiber at the end face of the ferrule after the optical fiber has been positioned as described above. The adhesive can then be fully cured along the entire passageway by heating the assembly in an oven or by any other suitable curing technique.
[0018] Further, this invention may make use of a method and apparatus that provide a work station incorporating at least one of the following: (1) fiber placement into the passageway of a ferrule, (2) adhesive injection into the passageway of the ferrule, (3) fiber positioning in such a way as to compensate for eccentricity of the passageway relative to the longitudinal centroidal axis of ferrule such that the optical fiber position relative to the passageway is substantially straight for a predetermined distance, (4) tacking the end portion of the fiber to the end face of the ferrule, (5) curing the adhesive in the passageway of the ferrule, (6) cutting off the end portion of the fiber projecting from the end face of the ferrule, and (7) polishing the end face of the ferrule and optical fiber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The above and other embodiments, objects, features, and advantages of the invention will become more apparent from the following description of certain preferred embodiments thereof, when taken in conjunction with the accompanying drawings in which:
[0020] [0020]FIG. 1 is a diagrammatic view of a ferrule illustrating bowing of an optical fiber in a bore, as can occur with prior art positioning methods;
[0021] [0021]FIG. 2 is a perspective view of an apparatus for mounting a plurality of fiber optic connectors to position and to secure an optical fiber in a ferrule of each connector in accordance with an embodiment of this invention;
[0022] [0022]FIG. 3 is an exploded view of the apparatus of FIG. 2;
[0023] [0023]FIG. 4 is an exploded view of a portion of the apparatus of FIG. 2, showing details of the weight positioning mechanism;
[0024] [0024]FIG. 5 is an enlarged partial perspective view showing a fiber optic connector mounted in the apparatus of FIG. 2, viewed generally from above and to the rear of the fiber optic connector;
[0025] [0025]FIG. 6 is a further enlarged partial perspective view of a fiber optic connector mounted in the apparatus of FIG. 2, viewed generally from above and from in front of the fiber optic connector;
[0026] [0026]FIG. 7 is an enlarged perspective view of the weight shown in FIG. 6, viewed generally from in front of the weight showing the end portion of the optical fiber extending from the fiber optic connector;
[0027] [0027]FIG. 8 is a schematic diagram of an apparatus for positioning an optical fiber in a passageway using an air jet in accordance with an embodiment of this invention;
[0028] [0028]FIG. 9 is a perspective view of an apparatus for positioning an optical fiber using an air jet in accordance with an embodiment of this invention; and
[0029] [0029]FIG. 10 is a partial enlarged perspective view of a portion of the apparatus of FIG. 9, showing an optical fiber optic connector mounted in the apparatus.
DETAILED DESCRIPTION OF THE INVENTION
[0030] This invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
[0031] [0031]FIG. 1, as previously discussed, illustrates the effect of directing an end portion of an optical fiber 12 to desired position in a bore 14 of a ferrule 10 . The optical fiber 12 is shown installed in the bore 14 of the ferrule 10 . A force F is applied to the optical fiber 12 , downward in FIG. 1, to push the optical fiber 12 to a lower side 13 of the bore 14 . The optical fiber 12 is thus subjected to a bending moment that causes the optical fiber 12 to bend towards an upper side 15 of the bore 14 as shown; the degree of bending is exaggerated in the drawing for clarity of illustration. If the optical fiber 12 is tacked at an end face 16 at the lower side 13 and ferrule 10 is polished so as to remove material back to the broken line in FIG. 1, then the resulting end portion of the optical fiber 12 will no longer be at the lower side 13 of the bore 14 because of the bowed shape of the optical fiber 12 . This invention seeks to overcome this problem.
[0032] FIGS. 2 - 7 depict an optical fiber positioning apparatus 20 in accordance with an embodiment of this invention. This apparatus includes a housing formed by a plate-shaped bottom wall 22 , a plate-shaped strong back 24 overlying the bottom wall, a shell 26 configured as a shallow box mounted atop the strong back 24 , and a base plate 28 mounted with the shell 26 atop its bottom wall 22 . A connector tray assembly 30 and a curing block assembly 40 are mounted within the shell 26 atop the base plate 28 . The connector tray assembly 30 includes a horizontally slidable tray 31 having an upstanding wall 32 in which a plurality of connector-receiving notches or cut-outs 34 are formed spaced apart along the length of the wall 32 . Aligned with the notches 34 are a plurality of connector receptacles 44 formed in a curing block 42 of the curing block assembly 40 .
[0033] Each notch 34 in the connector tray wall 32 is preferably configured to receive the outer housing 18 of a fiber optic connector. In alternate embodiments (not shown), each notch 34 could be configured to receive any portion of the fiber optic connector. Further, although the fiber optic connector may include a variety of single fiber ferrules with differently configured passageways (e.g., bores, channels, grooves, etc.), including SC, LC, MU, BLC, and similar ferrules, the housing 18 of the illustrated embodiment is shown as an SC connector by way of example, but not of limitation. As such, the SC connector will be hereinafter described with reference to the apparatus and method of this invention. The housing 18 has a generally cylindrical outer surface in which a groove is formed such that the groove defines a pair of flats 19 on opposite sides of the housing 18 parallel to each other for interfacing with walls 36 of the notches 34 in the wall 32 of the connector tray 31 . As a result of a close-fitting interaction between the walls 36 of the notch 34 and the flats 19 of the groove in the connector housing 18 , the connector housing 18 can be inserted into the notch 34 in only one rotational orientation. The ferrule 10 is mounted in the housing 18 such that when the connector is inserted into the notch 34 in the direction of eccentricity of the bore 14 in the ferrule 10 of the connector is straight upward. In practice this would be accomplished by measuring the magnitude and direction of eccentricity of the bore 14 in the ferrule 10 , mounting the ferrule 10 in an inner housing 11 of the connector such that the direction of eccentricity of the bore 14 is in a predetermined orientation with respect to the inner housing 11 , and then mounting the inner housing 11 in the outer housing 18 in a predetermined orientation. Of course, in a type of connector having the ferrule mounted directly in an outer housing (i.e., not having an inner housing), the ferrule would be mounted in the outer housing in a predetermined orientation. This can be achieved, for example, by forming a keyway in the ferrule in a predetermined position with respect to the direction of eccentricity of the passageway for engaging a key formed in the housing or in any other suitable way. The particular technique with which the ferrule is mounted in the connector to position the direction of eccentricity in the desired orientation is not important to this invention.
[0034] The curing block 42 , as noted, defines receptacles 44 for receiving the connectors. The receptacles 44 are cylindrical in configuration, with a slightly larger diameter than the outer diameter of the housings 18 of the connectors, such that the connectors can be slid axially into the receptacles 44 . The tray 31 of the connector tray assembly 30 in which the connectors are held is slidable axially relative to the receptacles 44 of the curing block 42 , via a slide arrangement 38 . Once the connectors are mounted in the connector tray assembly 30 , the tray 31 is slid toward the curing block 42 , thereby inserting the connectors into the receptacles 44 of the curing block 42 , until the tray 31 abuts a stop 39 that is positioned such that the end faces of the ferrules and optical fibers are in a desired axial location relative to the positioning assembly of the apparatus as further described below.
[0035] In an embodiment, the positioning assembly comprises the weight assembly depicted in detail in FIGS. 4 - 7 . The weight assembly includes a lifting bar 46 of elongate form extending parallel to and spaced from the row of receptacles 44 . For each receptacle 44 in the curing block 42 , a pair of weight supports 48 extend from the lifting bar 46 toward the receptacle 44 and are spaced on opposite sides of a central axis of the respective receptacle 44 . The weight supports 48 in the illustrated embodiment are configured as cylindrical rods, at the free ends of which an annular groove is formed. A plate-shaped weight 50 having a pair of slots 52 slightly wider than the diameter the weight supports 48 in the region of the annular grooves is hung on each pair of weight supports 48 such that the slots 52 engage the grooves of the weight supports 48 . The slots 52 are narrower than the full diameter of the weight supports 48 ; thus, the weights 50 are constrained to remain in the grooves at the free ends of the weight supports 48 . Each weight has an aperture 54 therethrough for receiving the optical fiber 12 .
[0036] The lifting bar 46 is vertically movable between raised and lowered positions. In the raised position, the lifting bar 46 and weight supports 48 thereof lift the weights 50 so that they do not bear on the optical fibers 12 of the connectors; this position of a weight 50 is depicted in FIG. 7. In the lowered position of the lifting bar, the weights 50 are lowered so that they are supported by the optical fibers 12 . The weights thus exert a downward force on the optical fibers that push the optical fibers to the lower sides 13 of the bores 14 in the ferrules 10 . In an embodiment, the weights 50 have a mass of about 0.1 to 5.0 grams each, more preferably about 0.3 to 0.5 grams each, and are positioned at least about 0.5 mm from the end faces of the ferrules 10 , more preferably about 0.5 to 1.0 mm. Accordingly, the bending moment exerted on a optical fiber by a weight 50 is less than about 4.9×10 −5 N-m, more preferably is less than about 1×10 −5 N-m, and most preferably is less than about 3.9×10 −6 N-m, where the lever arm of the moment is measured from the ferrule end face 16 to the point along the optical fiber at which the weight is supported. It should be noted that although it is desirable to position the weight as close to the end face of the ferrule as possible in order to minimize the bending moment on the optical fiber, if the weight 50 is positioned too close to the end face of the ferrule, then the weight could become adhered to the ferrule because adhesive from the bore may be present at the end face. Thus, for this reason it is advantageous to provide a slight separation (e.g., from about 0.5 mm to about 1.0 mm) between the ferrule end face and the weight.
[0037] It has been found that when this arrangement is used in combination with an adhesive of suitable viscosity at the temperature prevailing when the weights 50 are hung on the optical fibers 12 (i.e., generally room temperature), the optical fibers are positioned to lower sides 13 of the bores 14 in the ferrules 10 with substantially no bending of the optical fibers taking place. In particular, the axis of the optical fiber remains straight from about 0.025 μm to about 0.05 μm for a distance of at least about 50 μm along the bore from the ferrule end face. Preferably, an epoxy adhesive is used for securing the optical fibers in the passageway, and the adhesive preferably has a viscosity of less than about 27,000 cps at room temperature, and more preferably, of about 27,000 cps at room temperature. However, the invention can be practiced with various adhesives having a wide range of viscosities. The important consideration is to select the mass of the weight, the point of application of the weight (i.e., the axial distance from the ferrule end face to the weight), and the adhesive viscosity such that the weight is heavy enough to exert a downward force on the optical fiber to overcome the viscous forces of the adhesive, but not so heavy that a substantial amount of optical fiber bending occurs. It will be appreciated that various combinations of weight, distance from the ferrule end face, and adhesive viscosity may be employed to achieve this objective.
[0038] The lifting bar 46 of the apparatus is raised and lowered by an actuating mechanism that includes an actuating rod 60 rotatably supported in the curing block 42 via bearings 62 (only one visible in FIG. 4). The actuating rod 60 extends parallel to the row of receptacles 44 in the curing block 42 and is disposed beneath the lifting bar 46 . The lifting bar 46 is slidably engaged with a pair of vertical guide posts 64 secured in the curing block 42 , such that the lifting bar 46 slides up and down without substantially pivoting or rocking (i.e., the lifting bar 46 undergoes a substantially pure translation). The guide posts 64 extend through apertures 66 in the lifting bar 46 , and upper ends of the guide posts 64 extend above the lifting bar 46 . Coil compression springs 68 are slipped over the upper ends of the guide posts 64 and are held in a compressed condition bearing against the upper surface of the lifting bar 46 by a pair of E-clips 70 . Thus, the springs 68 urge the lifting bar 46 toward its lowered position in which the weights 50 are hung on the ends of the optical fibers 12 of the connectors. The lifting bar 46 is raised in opposition to the spring forces by a pair of eccentric cams 72 mounted on the actuating rod 60 . A knob 74 secured to the end of the actuating rod 60 that extends out one side of the curing block 42 and out one side of the shell 26 is used to turn the actuating rod 60 so as to cause the cams 72 to lift the lifting bar 46 up. The lifting bar 46 is fixed in its uppermost position by a catch mechanism (not shown) for the actuating rod 60 .
[0039] In use, the apparatus 20 is prepared for operation by turning the knob 74 to raise and fix the lifting bar 46 in its raised position. The tray 31 of the connector tray assembly 30 is slid axially away from the receptacles 44 of the curing block 42 so that connectors can be inserted into the notches 34 in the tray 31 . The connectors are prepared by injecting liquid adhesive into the bores 14 in the ferrules 10 , and inserting an optical fiber 12 into each bore 14 such that the optical fiber end projects from the end face 16 of the ferrule 10 . Once the connectors are mounted in the notches, the tray 31 is slid toward the curing block 42 , thereby inserting the connectors into the receptacles 44 of the curing block, until the tray 31 abuts the stop 39 . In this position of the tray 31 , the end faces of the ferrules preferably are spaced approximately from about at least about 0.5 mm to 1.0 mm from the weights 50 in the axial direction, and the optical fibers 12 of the connectors are inserted through the apertures 54 in the weights but there is no contact between the weights 50 and the optical fibers 12 . Next, the knob 74 is rotated to lower the lifting bar 46 to its lower position, thereby lowering the weights 50 onto the optical fibers 12 . The optical fibers 12 are thus pushed down toward the lower sides 13 of the bores 14 in the ferrules 10 . The entire apparatus 20 is then placed in an oven to cure the adhesive in the bores 14 . Preferably, with the preferred type of epoxy adhesive the oven should be at a temperature of about 150° C., although the curing temperature will depend on the particular type of adhesive used. The apparatus is then removed from the oven and the connectors are removed from the apparatus. In alternative embodiments, the adhesive may be cured by other suitable curing techniques, such as, for example, UV and the like.
[0040] FIGS. 8 - 10 depict an alternative embodiment of an apparatus in accordance with the invention. In this embodiment, the force for positioning the optical fiber 12 in the bore 14 of the ferrule 10 is provided by a directing a pressurized fluid or gas onto at least a portion of the optical fiber. FIG. 8 diagrammatically illustrates the apparatus 120 . The apparatus includes a nozzle 122 supplied with pressurized fluid from a suitable source 124 via a controllable shutoff valve 126 . Preferably, the fluid comprises air; however, alternate embodiments may use other suitable fluids. The nozzle 122 is positioned such that a tip of the nozzle from which the fluid is discharged is closely adjacent to the optical fiber 12 and the end face 16 , such that the jet of fluid produced by the nozzle is directed substantially orthogonal to the axial direction of the optical fiber 12 . Preferably, the fluid jet should impinge on the optical fiber 12 at a location spaced no more than at least about 0.5 to 1.0 mm from the end face 16 of the ferrule 10 . The pressurized air supply 124 preferably has a plenum pressure of about 5 to 15 psig.
[0041] The discharge orifice of the nozzle 122 preferably is not circular, but rather is elongated in a direction transverse to the optical fiber axial direction to produce a thin stream of air. In the preferred embodiment, the nozzle discharge orifice is an oval in which the longer sides of the oval have a length of at least about 0.8 mm and the width of the orifice (i.e., the spacing between the straight sides) is at least about 0.5 mm.
[0042] The jet of air from the nozzle 122 pushes the optical fiber 12 to the lower side 13 of the bore 14 in the ferrule 10 . Once the optical fiber 12 has been positioned in the bore 14 , a beam of laser radiation from a laser 130 is directed, via a focusing lens 132 , onto a portion of the end face 16 surrounding the optical fiber so as to locally heat the ferrule or the adhesive at the end face 16 . This causes the adhesive in at least a portion of the bore 14 adjacent the end face 16 to be cured, or at least partially cured, so as to tack the optical fiber 12 in place at the desired position in the bore 14 . The connector is then put into an oven or is otherwise heated to a suitable curing temperature for a sufficient time to completely cure the adhesive along the entire length of the bore 14 . As noted previously, with the preferred type of epoxy adhesive a suitable curing temperature is about 150° C.
[0043] The laser 130 preferably is controllable to regulate the intensity of heating of the ferrule or the adhesive so as to produce a desired temperature of the ferrule at the end face 16 . The laser 130 can be calibrated so that the relationship between the power of the laser radiation and the temperature at the end face are known, and then the power of the laser can be regulated to produce the desired temperature. Preferably, the temperature at the end face is about 150° C., but it will be recognized that different adhesives may require different temperatures to sufficiently cure the adhesive to tack the optical fiber 12 in place.
[0044] [0044]FIG. 9 depicts a fixture 140 in accordance with the invention for securing a connector in position to be operated on by the air jet from the nozzle 122 . The fixture 140 includes at least one receptacle 142 extending through a wall 144 of the fixture for receiving a connector. A holding structure called a “bullet” 146 supports the connector and is positioned in the receptacle 142 from left to right as shown by arrow 150 such that the end face 16 of the ferrule 10 with fiber 12 projects from the receptacle on the right as shown in further detail in FIG. 10. The air nozzle 122 is mounted to the fixture 140 with a tip of the nozzle positioned so that it is in close proximity to the optical fiber 12 projecting from the ferrule 10 of the connector and in close proximity to the end face 16 of the ferrule. FIG. 10 illustrates the position of the nozzle relative to the optical fiber 12 and ferrule 10 .
[0045] The fixture 140 , as shown in FIG. 9, also advantageously may include a second receptacle 148 for receiving the connector after the optical fiber 12 has been secured in place in the bore 14 of the ferrule 10 by curing the adhesive. The second receptacle 148 positions the connector so that the end portion of the optical fiber projecting from the ferrule 10 can be cut off by a cut-off device (not shown) in preparation for polishing of the end face 16 and optical fiber 12 . Of course, it will be recognized that a fixture in accordance with the invention could include a plurality of receptacles and a plurality of air nozzles associated with each receptacle so that multiple connectors can be processed simultaneously, and could include a plurality of receptacles for positioning multiple connectors to have the optical fiber ends cut off.
[0046] Further, this invention may make use of a method and apparatus that provide a work station incorporating at least one of the following: (1) fiber placement into the passageway of a ferrule, (2) adhesive injection into the passageway of the ferrule, (3) fiber positioning in such a way as to compensate for eccentricity of the passageway relative to the longitudinal centroidal axis of ferrule such that the optical fiber position relative to the passageway is substantially straight for a predetermined distance, (4) tacking the end portion of the fiber to the end face of the ferrule, (5) curing the adhesive in the passageway of the ferrule, (6) cutting off the end portion of the fiber projecting from the end face of the ferrule, and (7) polishing the end face of the ferrule and optical fiber. Finally, this invention includes optic fiber assemblies that incorporated ferrules or connectors made from the various embodiments described herein.
[0047] Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. For example, the embodiments discussed herein are directed to a ferrule having a centralized bore for a passageway. However, the positioning method and apparatus apply to ferrules having other types of passageways, such as, for example, ferrules with non-encapsulated or partially encapsulated passageways, such as channels and grooves. Another modification or embodiment, for example, may include other means for applying the force to the optical fiber can be used, such as a thin wire placed in tension and bearing against the optical fiber. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. | Eccentricity of a optical fiber installed in a passageway of a ferrule is minimized by imposing a force on the end of the optical fiber projecting from the passageway at the ferrule end face to push the optical fiber to a desired position in the passageway, prior to curing an adhesive used for fixing the optical fiber in the passageway, so as to compensate for eccentricity of the passageway. In one embodiment, the force is imposed on the optical fiber by hanging a weight on the optical fiber. In another embodiment, the force is imposed on the optical fiber by using a pressurized jet of fluid. The point of application of the force, the magnitude of the force, and the viscosity of the adhesive are selected such that minimal optical fiber bending occurs, thereby assuring that the optical fiber is positioned at the desired position in the passageway for an appreciable distance from the ferrule end face along the passageway. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. national stage application under 35 U.S.C. §371 of International Application No. PCT/DE2014/100119, filed on Apr. 3, 2014, and claims benefit to German Patent Applications No. DE 10 2013 103 370.9 filed on Apr. 4, 2013, and DE 10 2013 112 035.0, filed on Oct. 31, 2013. The International Application was published in German on Oct. 9, 2014, as WO 2014/161535 A2 under PCT Article 21(2).
FIELD
[0002] The invention relates to a method and a device for separating, in particular breaking up, a substrate, in particular a glass substrate, which is usable for example as an interposer or microcomponent, using a laser beam.
BACKGROUND
[0003] A method of this type and a device for carrying out the separation process are used in practice for example for separating or splitting wafers, glass substrates and plates. Substrates of this type are also used for example as interposers for electrically connecting the terminals of a plurality of homogeneous or heterogeneous microchips.
[0004] In practice, separation by cutting is a critical step in the processing of wafers or glass substrates, which is typically based on the use of diamond cutting tools and carried out for example at a speed of 30 cm/s for displays. However, the quality of the edges which can be achieved by this process is unsatisfactory, and leads to significant drawbacks in terms of the service life, quality and reliability of the product, but also in the resulting cleaning costs.
[0005] In this context, it is found to be a challenge to process the substrate into usable elements. The prior art has not yet addressed, in particular, the economical production of the plurality of separating faces in a substrate for example in the production of wafers.
[0006] US 2013/126573 A1 discloses a separating method for producing a substrate in which the substrate is irradiated with one or more pulses of a focused laser beam. In this context, the substrate is transparent to the focused laser beam, whilst the laser pulses are selected in such a way, in terms of the energy and pulse duration, that a duct-like filament is produced within the substrate. By displacing the substrate relative to the focused laser beam, additional, spatially separated filaments are produced, which thus define a separating face. The substrate consists for example of glass, crystal, quartz, diamond or sapphire. For a corresponding material thickness of the substrate, a plurality of focal points of the focused laser beam are selected in such a way that filaments are produced in at least one of the two or more layers. In this context, the filament produced by the focused laser beam in a first layer should propagate into at least one additional layer and produce a second filament in this further layer. Further, it may also be provided for a second beam focus to be produced in a second layer. In this method, the use of comparatively expensive femtosecond or picosecond lasers and the complex configuration, in which a pulse sequence of individual pulses and of particular repetition rates of the pulse sequences in accordance with particular prescriptions is provided, are found to be disadvantageous. In particular, a time delay between successive pulses in the pulse sequence is smaller than a duration of the relaxation of a material modification.
[0007] The term “stealth dicing” refers to a laser machining method in which in a first step a laser beam acts on a layer within a substrate. In a second step a tensile stress is applied so as to separate the substrate along the action points in the layer. This layer is an internal surface in the wafer, which is modified by the laser within the substrate during the processing and forms the starting point for dividing the substrate during the processing. The tensile stress subsequently brings about the separation of the substrate into small portions.
[0008] A method of this type for separating a substrate, for example a semiconductor substrate in the production of a semiconductor component or the like, is known for example from U.S. Pat. No. 8,518,800 B2. In this context, the substrate is irradiated with laser light in such a way that a multiphoton absorption phenomenon is produced within the substrate, whereby a light convergence point and thus a modified area are formed within the substrate. By forming a cutting onset point region within the substrate, a break is produced in the substrate in the direction of the thickness extent thereof, without external action or whilst exerting a force, starting from the cutting onset point region which acts as the starting point.
[0009] EP 2 503 859 A1 further discloses a method in which a glass substrate is provided with through-holes, the glass substrate consisting of an insulator such as glass, for example silicate glass, sapphire, plastics material or ceramic and semiconductors such as silicon. The glass substrate is irradiated using a laser, for example a femtosecond laser, which is focused on a focal point at a desired position within the glass substrate. The through-holes are produced by a method in which the regions of the glass substrate which have been modified by the laser are dipped in an etching solution and the modified regions are thus removed from the glass substrate. This etching makes use of the effect whereby the modified region is etched extremely rapidly by comparison with the unmodified regions of the glass substrate. Blind holes or through-openings can be produced in this manner. A copper solution is suitable for filling the through-opening. To achieve a desired depth effect, in other words a through-hole between the outer substrate faces, the focal point has to be displaced during continuous irradiation, in other words tracked in the direction of the z-axis.
[0010] More generally, the combination of selective laser treatment with a subsequent etching process in the form of selective laser-induced etching is also known as ISLE (in-volume selective laser-induced etching).
[0011] DE 10 2010 025 966 B4 further discloses a method in which in a first step focused laser pulses are directed onto the glass substrate, the radiation intensity of said pulses being high enough to result in local athermal decomposition along a filament-like track in the glass. In a second method step, the filament-like tracks are expanded into holes by supplying high-voltage power to opposing electrodes, resulting in dielectric breakdowns through the glass substrate along the filament-like tracks. These breakdowns expand under electrothermal heating and evaporation of hole material, until the process is halted by switching off the power supply upon achieving the desired hole diameter. Alternatively or in addition, the tracks may also be expanded using reactive gases, which are directed onto the hole sites using nozzles. The through-opening sites may also be expanded using supplied etching gas. The comparatively complex process, resulting from the fact the glass substrate initially has to be broken through by the athermal decomposition and the diameter of the filament-like tracks has to be expanded into holes in the following step, has proved to be disadvantageous.
[0012] Further, U.S. Pat. No. 6,400,172 B1 discloses the introduction of through-openings in semiconductor materials by laser.
SUMMARY
[0013] An aspect of the invention provides a method for separating a substrate using an optical system, a thickness of the substrate not exceeding 2 mm in a region of a separating line, the method comprising: applying pulsed laser radiation having a pulse duration (t) to a substrate material of the substrate, which material is transparent at least in part to a laser wavelength, the laser radiation being focused using the optical system having an original focal depth (f1), an intensity of the laser radiation leading to a modification of the substrate along a beam axis (Z) of the laser radiation, but not to material removal which goes all the way through, and the pulsed laser radiation being moved along any desired separating line parallel to the primary extension plane of the substrate, bringing about a subsequent separation process along the separating line, wherein the pulsed laser radiation is focused by the same optical system, which is unchanged per se, at a focal depth (f2) different from the original focal depth (f1), by non-linear self-focusing within the pulse duration (t) of an individual pulse (P).
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention will be described in even greater detail below based on the exemplary figures. The invention is not limited to the exemplary embodiments. All features described and/or illustrated herein can be used alone or combined in different combinations in embodiments of the invention. The features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following:
[0015] FIG. 1 is a schematic drawing of a prior art method;
[0016] FIG. 2 is a flow chart comprising a plurality of method steps for introducing a plurality of through-openings into a substrate;
[0017] FIG. 3 shows the intensity-dependent focal point during an individual pulse; and
[0018] FIG. 4 is a graph showing the intensity distribution over time during the duration of an individual pulse.
DETAILED DESCRIPTION
[0019] An aspect of the invention provides an option for substantially simplifying a method and a device for separating a substrate, and in particular for reducing the time taken to carry this out.
[0020] An aspect of the invention thus provides a method in which the laser radiation is focused by non-linear self-focusing within the pulse duration of a single pulse by the unchanged optical system using a focal depth differing from the original focal depth. The invention makes use of the fact that the intensity of a pulsed laser is not constant for an individual pulse, but rather has an intensity which increases to a maximum and subsequently falls away over the temporal progression of the individual pulse. Because the refractive index also increases to a maximum as a result of the increasing intensity, in a manner corresponding to a normal distribution over the temporal progression for an individual pulse, the focal depth of the optical system, in other words the distance from a laser machining head or the lens, changes, independently of the geometric focal point determined by the focusing optics.
[0021] This effect of non-linear self-focusing is made use of in that the distance between the focal points between a maximum and a minimum intensity at least corresponds to the desired longitudinal extent, in other words to the thickness in the region of a separating line. In a surprisingly simple manner, this results in a spatial displacement in the direction of the beam axis during the duration of an individual pulse, which leads to the desired modification in the region of the entire primary extension, in the direction of the beam axis. Tracking of the focal point, which is unavoidable in the prior art, can be omitted in this case. Thus, in particular, no control system for moving the laser focus through the substrate is required. In this way, a modified region of the substrate is produced along the separating line as a separating face or predetermined breaking face. Thus, according to the invention, not only is the control system outlay required for this purpose omitted, but the machining duration can also be considerably reduced, for example to the duration of an individual pulse. The non-linear refractive index of the transmissive medium is a linear function of the intensity, and so the selection of a suitable material and suitable dimensions is dependent on the intensity of the laser radiation used.
[0022] In this context, the laser beam is directed onto the substrate sufficiently briefly that the substrate is merely modified along a beam axis of the laser beam, without destruction which penetrates through the substrate occurring, anisotropic material removal for example being carried out in the next step in the regions of the substrate which have previously undergone modification by means of the laser beam, so as thus to carry out the separation optionally in connection with an assisting external force action.
[0023] The laser power input is used to excite or trigger a reaction and a modification by conversion, the effect of which is only made use of for or only leads to the desired material removal in the subsequent method step.
[0024] Because the separation process, on the basis of the modification and optionally subsequent anisotropic material removal, is carried out by an etching method, it is possible to use a planar-action removal method, which only places very low requirements on the process, rather than a sequential one for the separation process. Instead, over the duration of action, the material duration can be carried out quantitatively and qualitatively for all regions which are pre-treated in the described manner and correspondingly modified, reducing the expenditure of time for producing the plurality of recesses or through-openings considerably overall.
[0025] The focal point at minimum intensity may be directed onto an outer surface of the substrate. However, it has already been found to be particularly promising if the laser radiation is focused onto a remote side of the substrate at a distance therefrom, in such a way that the focal point of the laser radiation is set so as to be positioned on a rear side, remote from the laser radiation, at a distance from the surface of the substrate. As a result, the laser beam is initially directed onto a focal point positioned outside the substrate. The refractive index which changes as a result of the increasing intensity subsequently leads to a spatial displacement of the focal point through the substrate along the beam axis. This ensures that a sufficiently high intensity for producing the modification is applied to every focal point within the substrate.
[0026] The duration of the beam action may, of course, comprise a plurality of pulse durations for an unchanged relative position of the laser machining head with respect to the substrate, for example so as further to optimise the modification of the substrate material. However, it is particularly advantageous if the laser beam is deflected onto each focal point for the duration of a single pulse. In this way, the previous and subsequent pulses of the laser beam are directed onto positions spaced apart in the plane of the substrate, in such a way that adjacent focal points are spaced apart in the plane of the substrate.
[0027] Preferably, the distance between the modifications to be produced adjacently in the substrate along the separating line is selected in such a way that the modified regions are directly mutually adjacent or have a very small distance between them.
[0028] The modifications may be produced by laser machining in which positioning of the laser machining head and the laser machining alternate. However, constant relative movement between the laser beam or laser machining head and the substrate is preferably carried out while the laser radiation is deflected onto the substrate, in such a way that the laser beam is continuously guided in a “floating” movement over the substrate, in such a way that an interrupted change in the relative position results in an extremely rapid machining duration. In particular, the relative position of the substrate with respect to the laser beam can be changed at a constant speed, in such a way that for a constant pulse frequency the spacing of the modifications to be produced adheres to a predetermined grid dimension.
[0029] Particularly preferably, the laser is operated at a wavelength to which the substrate is transparent, ensuring penetration of the substrate. In particular, this ensures a substantially cylindrical modification region coaxial with respect to the laser beam axis, which leads to a constant diameter of the through-opening or recess.
[0030] Further, it may also be advantageous if the laser also additionally removes a surface region so as to configure the action region in a manner resulting in a conical inlet region to the through-opening. In this manner, the subsequent separation process is simplified. In addition, the action of an etching agent is concentrated in this region, for example.
[0031] In another, also particularly promising embodiment of the method, the substrate is coated in a planar manner with an etch resist on at least one surface prior to the laser treatment. As a result of the action of a laser beam, the etch resist is removed on at least one surface in a dot-like action region and the modification is produced in the substrate simultaneously. In this way, the unmodified regions are protected against undesired action in the subsequent etching process, and the surface is therefore not damaged. The etch resist does not prevent the modification of the substrate positioned below. Rather, the etch resist is either permeable to the laser radiation or it is removed in a near dot-like manner by the laser radiation, that is to say evaporated, for example. Further, the possibility is not excluded that the etch resist may contain substances which act to promote the modification, for example which accelerate the modification process.
[0032] Fundamentally, the method is not limited to particular material compositions of the substrate. However, it is particularly promising for the substrate to comprise an aluminosilicate, in particular a boroaluminosilicate, as a significant material proportion.
[0033] A defined separating face can be produced along the modified regions, it optionally being possible to optimize the separation using additional external force action or a thermal after-treatment, in such a way that a subsequent etching method can be rendered superfluous.
[0034] Preferably, the material separation is brought about in the modified regions of the substrate by anisotropic material removal by liquid etching, dry etching or vapor phase etching, and optionally also by high-voltage or high-frequency evaporation. Optionally, the separation process may further be promoted by an external force action, in particular a tensile force or compressive force. Alternatively, the separation process can also be carried out without difficulty without external force actions if the substrate is biased under internal stress.
[0035] The second object is achieved according to the invention by a device comprising a laser machining head for deflecting laser radiation onto a substrate, in that the device is equipped with a transmissive medium, which in particular is provided with at least one planar face or is, for example, configured as a planar plate, and which has a higher intensity-dependent refraction index than air, and which is arranged in particular between the laser machining head and the substrate in such a way that the laser radiation can be deflected through the transmissive medium onto the substrate. As a result, according to the invention the intensity-dependent refractive index of the transmissive medium is exploited so as to produce an axial change in the focal point during the duration of each individual pulse and the accompanying fluctuation in intensity during the individual pulse, in connection with a pulsed laser. Thus, unlike in the prior art, the focal point is not unchanged, at least during the duration of an individual pulse, but rather the focal point is displaced along a line on the beam axis with respect to the total duration of the individual pulse. It is easy to see what significant advantages result in the present invention from the fact that the focal point is displaced without tracking of the focusing optics of the laser machining head. In particular, this greatly reduces the machining duration and also the control system outlay. For example, in a planar substrate the tracking of the z-axis can be omitted. To produce the desired separating face, a large number of laser pulses are introduced into the substrate mutually adjacently.
[0036] In principle, a variant is also conceivable in which the transmissive medium is arranged on the laser machining head upstream of focusing optics thereof in the direction of the beam path, in such a way that the laser radiation is initially deflected through the transmissive medium and subsequently through the focusing optics and directed onto the substrate.
[0037] The effect of the intensity-dependent light refraction can, of course, be adapted to the respective application, for example in that the transmissive medium is adapted or replaced accordingly or in that the laser beam passes through a plurality of transmissive media or through the same medium repeatedly.
[0038] The focal point may be directed onto a rear face of the substrate, remote from the laser machining head, and the transmissive medium may be formed in such a way that the intensity-dependent focal point reaches a front face, facing the laser machining head, at the intensity maximum. However, it is particularly expedient in practice if the laser radiation can be deflected onto a focal point at a distance from a rear face of the substrate, remote from the laser machining head, in such a way that the rear face of the substrate is reached during the increasing intensity progression rather than at an intensity minimum. This ensures a laser radiation intensity within the substrate which is always sufficient for the modification which is to be achieved.
[0039] In principle, any pulsed laser is suitable for the machining, a laser having a pulse duration of less than 50 ps, preferably less than 5 ps, having been found to be particularly expedient.
[0040] In addition, it is particularly expedient if, for focusing, the laser machining head has focusing optics having a numerical aperture (NA) greater than 0.3, in particular greater than 0.4.
[0041] A particularly promising embodiment of the device according to the invention is also achieved in that the focusing optics have a gradient index lens. As a result of a lens of this type, also known as a GRIN lens, the refractive index which decreases in the radial direction results in the reduction in intensity which otherwise occurs being generally compensated in the edge region of the lens.
[0042] It is further found to be advantageous if the transmissive medium consists of glass, in particular quartz glass, so as to provide a pronounced intensity-dependent refractive index.
[0043] In this context, the transmissive medium is preferably connected to the laser machining head and arranged so as to be movable together therewith and arranged in particular replaceably on the laser machining head. Rapid fixing, for example, is suitable for this purpose.
[0044] Preferably, the device is equipped with a continuously emitting laser in addition to a pulsed laser, the transmissive medium being transparent to the wavelength of the continuously emitting laser, and the continuously emitting laser being directed onto the glass substrate through the medium or directed onto the glass substrate while circumventing the transmissive medium. The wavelengths of the pulsed laser and of the continuously emitting laser may be different. Further, the laser radiation from the different laser sources may be directed onto the glass substrate from different sides.
[0045] FIG. 1 is a schematic drawing of a laser machining method also known as “stealth dicing”. As can be seen, in this context the laser beam is directed onto a special intermediate layer within a substrate, said layer being modified by the laser radiation to form the starting point for the subsequent separation of the substrate. An external tensile stress subsequently brings about the separation of the substrate into sub-regions along the action points in the layer.
[0046] FIG. 2 shows the individual method steps of introducing a plurality of through-openings into an interposer 1 , intended as a contacting element in circuit board production, comprising a substrate 2 . For this purpose, laser radiation 3 is directed onto the surface of the substrate 2 . The substrate 2 comprises a boroaluminosilicate as a significant material proportion, so as to ensure thermal expansion similar to that of silicon. The material thickness d of the substrate 2 is between 50 μm and 500 μm. The duration of action of the laser radiation 3 is selected to be extremely short, in such a way that merely a modification of the substrate 2 occurs concentrically about a beam axis of the laser beam, without resulting in significant destruction or considerable material removal of the substrate material. In particular, the duration of action is limited to the individual pulse. For this purpose, the laser is operated at a wavelength to which the substrate 2 is transparent. A region 4 modified in this manner is shown in FIG. 2 b . In a following method step, shown in FIG. 2 c , the modified regions 4 of the substrate 2 which have previously undergone modification by the laser radiation 3 form a separating face 5 along the linear succession of modified regions 4 in the substrate.
[0047] The following describes in more detail an important effect during the laser machining of the substrate 2 with reference to FIGS. 3 and 4 . This is the intensity-dependent focal point during an individual pulse P. The invention is based on the finding that the intensity I of an individual pulse P of the laser radiation 3 is not constant, but rather has an intensity which increases from a minimum I a through an average I b to a maximum I c and subsequently decreases over the temporal progression of the individual pulse as shown in FIG. 4 , for example, in accordance with a normal distribution. Simultaneously, as a result of the variable intensity I, the refractive index, in particular also of a transmissive medium 8 , changes in relation to an individual pulse P over the temporal progression t. As a result, the intensity-dependent focal points 9 a , 9 b , 9 c of the laser radiation 3 , which are shown in FIGS. 3 a to 3 c , also change independently of the geometric focal point determined by focusing optics of a laser machining head 10 . This effect is amplified by the transmissive medium 8 , for example made of glass, which is arranged between the laser machining head 10 and the substrate 2 and which has a greater intensity-dependent refractive index than air, in such a way that the distance between the focal points 9 a , 9 c between a maximum intensity I c and a minimum intensity I a at least corresponds to the desired longitudinal extension, in other words to the depth of the recess to be produced or, if, as shown, a separating face 5 is to be produced, to the material thickness d of the substrate 2 . The intensity-dependent focal point 9 a , 9 b , 9 c thus migrates along the beam axis Z from a position, which is shown in FIG. 3 a and is at a distance from a rear face 11 of the substrate 2 , in the direction of the laser machining head 10 , and thus reaches all positions along the beam axis Z between the rear face 11 and a front face 12 facing the laser machining head 10 in a continuous movement, in such a way that the desired modification occurs in the region of the entire primary extension of the recesses which are subsequently to be produced.
[0048] Additionally, FIG. 3 a shows, merely schematically, an additional laser machining head 13 , which, to supplement a continuously emitting laser source connected to the laser machining head 10 , directs the laser radiation 3 of a pulsed laser onto the glass substrate 2 selectively through or circumventing the transmissive medium 8 . As a result, the intensity I, shown in FIG. 4 , of an individual pulse P of the laser radiation 3 is accordingly amplified by the intensity of the continuously emitting laser source.
[0049] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. Additionally, statements made herein characterizing the invention refer to an embodiment of the invention and not necessarily all embodiments.
[0050] The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B, and C” should be interpreted as one or more of a group of elements consisting of A, B, and C, and should not be interpreted as requiring at least one of each of the listed elements A, B, and C, regardless of whether A, B, and C are related as categories or otherwise. Moreover, the recitation of “A, B, and/or C” or “at least one of A, B, or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B, and C. | A method and device for separating a substrate with a laser beam. The duration of the laser beam's effect is extremely short, so the substrate is only modified concentrically about the laser beam axis (Z) without it degrading the substrate material. While the laser beam acts upon the substrate, the substrate moves relative to a laser machining head, producing plural filament-type modifications along a separating surface to be incorporated. The laser beam is initially diverted by a transmission medium having a higher intensity dependent refractive index than air, then reaches the substrate. The non-constant pulsed laser intensity increases to a maximum over the temporal course of the single pulse, then reduces, and the refractive index changes. The laser beam focus point moves between the substrate's outer surfaces along the beam axis (Z), reaching the desired modification along the beam axis (Z) without correcting the laser machining head in the z-axis. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a radio frequency identification (RFID) tag that exchanges information with an external device in a noncontact manner and a method of manufacturing the same. In some cases, among those skilled in the technical field corresponding to the present invention, the “RFID tag” referred to in this specification is called “RFID tag inlay” as an internal constituent member (inlay) for an “RFID tag”. In some other cases, this “RFID tag” is called “wireless IC tag”. Also, this “RFID” tag includes a noncontact-type IC card.
2. Description of the Related Art
In recent years, various types of RFID tags capable of noncontact information exchange by means of radio waves with external devices typified by reader/writers have been proposed. One of the various types of RFID tags proposed has an antenna pattern for radio wave communication and an IC chip mounted on a base sheet made of a plastic or paper. A conceivable usage form of such type of RFID tag is that the RFID tag is attached to an article and information about the article is exchanged with an external device for identification or the like of the article.
FIG. 1(A) is a front view and FIG. 1(B) is a sectional side view, respectively, of an example of an RFID tag.
The RFID tag 1 shown in FIGS. 1(A) and 1(B) is constituted by an antenna 12 provided on a base 13 formed of a sheet-like material such as a polyethylene telephthalate (PET) film, an IC chip 11 connected to the antenna 12 through bumps 16 , and a cover sheet 14 bonded to the base 13 by an adhesive 15 so as to cover the antenna 12 and the IC chip 11 .
The IC chip 11 constituting the RFID tag 1 is capable of exchanging information with an external device by performing wireless communication through the antenna 12 .
Various use forms including the above-mentioned use form have been conceived with respect to this type of RFID tag. In use of this type of RFID tag, how to reduce the manufacturing cost of the RFID tag has been a serious problem and various attempts have been made to solve this problem.
As one of the attempts to reduce the manufacturing cost, there is proposed the idea of forming an antenna by using a paste material which is made conductive by blending a metallic filler (Ag in ordinary cases) with a resin material such as an epoxy resin (Japanese Patent Laid-Open No. 2000-311226 (paragraph [0066])). If such a paste material can be used as a material for forming an antenna in place of a thin metallic material such as Cu, Al or Au that is conventionally used, it can largely contribute to a reduction in the manufacturing cost of the RFID tag.
When manufacturing the RFID tag in which, as shown in FIG. 1 , the IC chip 11 is connected to the antenna 12 formed on the surface of the base 13 that is a sheet-like PET member or the like through the bumps (metal protrusions) 16 formed on electrodes of the IC chip 11 , if the antenna 12 is formed by printing a paste material, a problem described below may arise with the connection between the IC chip 11 and the antenna 12 .
FIG. 2(A) shows a case where a metal is used as an antenna material and FIG. 2(B) shows a case where a paste is used as an antenna material for comparison.
An antenna 121 ( FIG. 2(A) ) formed of a thin sheet of a metal or an antenna 122 formed of a paste material ( FIG. 2(B) ) is formed on the base 13 formed of a PET. The bumps 16 are formed on electrodes 111 formed on the IC chip 11 in each of the cases shown in FIGS. 2(A) and 2(B) .
Each of the states shown in FIGS. 2(A) and 2(B) shows a state in which the IC chip 11 with bumps 16 is placed on the base 13 on which the antenna 121 or 122 is formed such that the bumps 16 face the base 13 and the IC chip 11 is connected to the antenna 121 or 122 through the bumps 16 .
In FIGS. 2(A) and 2(B) , illustration of the adhesive 15 and the cover sheet 14 shown in FIG. 1(B) is omitted. At the time of connection, the IC chip 11 is pressed from above as viewed in the figure with a jig (not shown). A pressing force is thereby applied from the bumps 16 to the antenna 121 or 122 . In the case of the antenna 121 made of a metallic material as shown in FIG. 2(A) , there is no problem with this pressing, since the hardness of the antenna 121 is high. In the case of the antenna 122 made of a paste material as shown in FIG. 2(B) , there is a problem described below. The paste material deforms by the pressing force received by the antenna 122 from the bumps 16 so as to conform to the shape of the bumps 16 , and compression bending of the paste material is thereby caused at the connection between the antenna 122 and the bumps 16 , resulting in pattern breakage and sinking at the bent portion. In this case, the necessary insulation distance cannot be maintained between the IC chip 11 and the antenna 122 . If this distance is changed, characteristics of the RFID tag including a wireless communication characteristic (hereinafter referred to as tag characteristics) are changed, which results in variations in tag characteristics when a large number of RFID tags are manufactured.
The method of mounting various types of IC chips on a circuit board apart from the RFID tag is being widely practiced. In ordinary cases, many bumps are formed on an IC chip and the pressing force per bump is small even when a paste material is used as a wiring material on a circuit board and, therefore, protrusion of the paste material is not a serious problem.
In contrast, in the case of the RFID tag, since the number of bumps provided in one IC chip for connection to the antenna is about two or four, the pressing force per bump is extremely large and thus the above-mentioned sinking problem arises. In order to reduce the pressing force, it is necessary to reduce the pressing force, which is applied by an apparatus for placing the IC chip on the base when placing the IC chip, to an extremely small value in comparison with the case of placing an ordinary IC chip on which many bumps are formed. Also, since an adhesive exists between the base and the IC chip, it is extremely difficult to reduce the pressing force to an extremely small value while enabling a reliable connection to be made in a short time.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above circumstances and provides an RFID tag using a paste as a material for an antenna and capable of avoiding the problem that the tag characteristics are changed by sinking of bumps, and a method of manufacturing the RFID tag.
According to the present invention, there is provided a first RFID tag having: a base; an antenna for communication provided on the base; a circuit chip connected to the antenna through bumps, the circuit chip performing wireless communication through the antenna, wherein the antenna is formed of a paste in which a metallic filler is blended with a resin material; and a stopper for limiting sinking of the bumps caused by a pressing force when the circuit chip with the bumps is connected to the antenna is provided adjacent to the bumps.
In the first RFID tag of the present invention, the stopper is provided to limit sinking described above with reference to FIG. 2(B) , thereby avoiding the problem due to variations in tag characteristics.
In the first RFID tag of the present invention, the stopper may be formed of a film formed on the circuit chip or the base and having holes in correspondence with the portions to which the bumps are connected. The stopper may alternatively be formed of a protrusion formed on a portion of the base adjacent to the portions to which the bumps are connected.
Further, in the first RFID tag of the present invention, a gap between the base and the circuit chip may be filled with an adhesive in which a filler is blended to fix the circuit chip and the base to each other when the circuit chip with the bumps is connected to the antenna, and the filler may constitute the stopper.
According to the present invention, there is provided a second RFID tag having: a base; an antenna for communication provided on the base; a circuit chip connected to the antenna through bumps, the circuit chip performing wireless communication through the antenna, wherein the antenna is formed of a paste in which a metallic filler is blended with a resin material; and a hard layer for limiting sinking of the bumps caused by a pressing force when the circuit chip with the bumps is connected to the antenna is provided at least at positions right below the bumps between the base and the antenna.
In the second RFID tag of the present invention, the hard layer is provided to limit sinking described above with reference to FIG. 2(B) , thereby avoiding the problem due to variations in tag characteristics.
According to the present invention, there is provided a third RFID tag having: a base; an antenna for communication provided on the base; a circuit chip connected to the antenna through bumps, the circuit chip performing wireless communication through the antenna, wherein the antenna is formed of a paste in which a metallic filler is blended with a resin material; and an electroconductive support for limiting sinking of the bumps caused by a pressing force when the circuit chip with the bumps is connected to the antenna is provided between the antenna and the bumps.
In the third RFID tag of the present invention, the support is provided to limit sinking of the bumps, as in the case of the RFID tags in the first and second aspects of the present invention. Therefore the tag characteristics of the RFID tag can be stabilized.
According to the present invention, there is provided a fourth RFID tag having: a base; an antenna for communication provided on the base; and a circuit chip connected to the antenna through bumps, the circuit chip performing wireless communication through the antenna, wherein the antenna is formed of a paste in which a metallic filler is blended with a resin material, and portions of the antenna right below the bumps are formed of a paste in which the ratio of blending of the metallic filler is changed in comparison with that in the paste for the portion other than the portions right below the bumps to limit sinking of the bumps caused by a pressing force when the circuit chip with the bumps is connected to the antenna.
In the fourth RFID tag of the present invention, the ratio of blending of the metallic filler for the portions of the antenna immediately below the bumps is changed to limit sinking, thereby stabilizing the tag characteristics of the RFID tag as well as those of the RFID tags in the first to third aspects.
According to the present invention, there is provided a fifth RFID tag having: a base; an antenna for communication provided on the base; and a circuit chip connected to the antenna through bumps, the circuit chip performing wireless communication through the antenna, wherein the antenna is formed of a paste in which a metallic filler for giving the necessary conductivity for the antenna to a resin material is blended with the resin material, and a hard filler for limiting sinking of the bumps caused by a pressing force when the circuit chip with the bumps is connected to the antenna is also blended with the resin material.
In the fifth RFID tag of the present invention, the antenna constituting the RFID tag is formed of a paste in which the hard filler (e.g., Cu, Pd, Ni or the like) as well as the metallic filler (e.g., Ag) are blended, thereby limiting sinking and stabilizing the tag characteristics.
According to the present invention, there is provided a first method of manufacturing an RFID tag, including: an antenna printing step of printing an antenna for communication on a base by using a paste in which a metallic filler is blended with a resin material; a circuit chip mounting step of mounting a circuit chip with bumps capable of performing wireless communication through the antenna, the circuit chip and the antenna being connected to each other through the bumps; and a stopper forming step of forming at a position adjacent to the bumps a stopper for limiting sinking of the bumps caused by a pressing force when the circuit chip with the bumps is connected to the antenna.
According to the present invention, there is provided a second method of manufacturing an RFID tag, including: an antenna printing step of printing an antenna for communication on a base by using a paste in which a metallic filler is blended with a resin material; a circuit chip mounting step of mounting a circuit chip with bumps capable of performing wireless communication through the antenna, the circuit chip and the antenna being connected to each other through the bumps; and a hard layer forming step of forming, at least at positions right below the bumps, between the base and the antenna a hard layer for limiting sinking of the bumps caused by a pressing force when the circuit chip with the bumps is connected to the antenna.
According to the present invention, there is provided a third method of manufacturing an RFID tag, including: an antenna printing step of printing an antenna for communication on a base by using a paste in which a metallic filler is blended with a resin material; a circuit chip mounting step of mounting a circuit chip with bumps capable of performing wireless communication through the antenna, the circuit chip and the antenna being connected to each other through the bumps; and a support forming step of forming between the antenna and the bumps an electroconductive support for limiting sinking of the bumps caused by a pressing force when the circuit chip with the bumps is connected to the antenna.
According to the present invention, there is provided a fourth method of manufacturing an RFID tag, including: an antenna printing step of printing an antenna for communication on a base by using a paste in which a metallic filler is blended with a resin material; and a circuit chip mounting step of mounting a circuit chip with bumps capable of performing wireless communication through the antenna, the circuit chip and the antenna being connected to each other through the bumps, wherein the antenna printing step includes a first printing step of printing a portion of the antenna other than the portions to which the bumps are connected by using the paste in which the metallic filler is blended with the resin material, and a second printing step of printing the portions of the antenna to which the bumps are connected by using a paste in which the ratio of blending of the metallic filler is changed in comparison with that in the paste used in the first printing step so as to form on the portions of the antenna to which the bumps are connected a hard electroconductive film for limiting sinking of the bumps caused by a pressing force when the circuit chip with the bumps is connected to the antenna.
According to the present invention, there is provided a fifth method of manufacturing an RFID tag, including: an antenna printing step of printing an antenna for communication on a base by using a paste in which a metallic filler is blended with a resin material; and a circuit chip mounting step of mounting a circuit chip with bumps capable of performing wireless communication through the antenna, the circuit chip and the antenna being connected to each other through the bumps, wherein the antenna printing step is a step of printing the antenna for communication on the base by using a paste in which a metallic filler for giving the necessary conductivity for the antenna to the resin material is blended with the resin material, and a hard filler for limiting sinking of the bumps caused by a pressing force when the circuit chip with the bumps is connected to the antenna is also blended with the resin material.
According to the present invention, as described above, a paste is used as the material of the antenna and sinking of the bumps of the circuit chip caused by a pressing force applied through the bumps is limited to stabilize the tag characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1(A) and 1(B) are a front view and a sectional side view respectively of an example of an RFID tag;
FIGS. 2(A) and 2(B) are diagrams respectively showing the case of using a metal as an antenna material and the case of using a paste as an antenna material for comparison;
FIG. 3 is a sectional view of an RFID tag according to a first embodiment of the present invention;
FIG. 4 is a sectional view of an RFID tag according to a second embodiment of the present invention;
FIG. 5 is a sectional view of an RFID tag according to a third embodiment of the present invention;
FIGS. 6(A) to 6(C) show an RFID tag which is an example of a modification of the third embodiment of the present invention;
FIG. 7 is a sectional view of an RFID tag according to a fourth embodiment of the present invention;
FIG. 8 is a sectional view of an RFID tag according to a fifth embodiment of the present invention;
FIG. 9 is a sectional view of an RFID tag according to a sixth embodiment of the present invention;
FIG. 10 is a sectional view of an RFID tag according to a seventh embodiment of the present invention;
FIG. 11 is a sectional view of an RFID tag according to an eighth embodiment of the present invention;
FIG. 12 is a sectional view of base and antenna portions of an RFID tag according to a ninth embodiment of the present invention;
FIGS. 13(A) to 13(C) show a method of forming bumps on electrodes of an IC chip;
FIG. 14 is a diagram showing a method of leveling bumps;
FIGS. 15(A) to 15(C) show the bump after leveling;
FIGS. 16(A) to 16(D) show a method of manufacturing the RFID tag having the stopper formed of polyimide film with holes as shown in FIG. 3 ;
FIGS. 17(A) to 17(C) show a method of manufacturing the RFID tag having a stopper formed of a PET with holes as shown in FIG. 4 ;
FIGS. 18(A) to 18(C) show a method of manufacturing the RFID tag having a stopper as shown in FIG. 5 ;
FIGS. 19(A) and 19(B) show a method of manufacturing the RFID tag including a plastic filler shown in FIG. 7 ;
FIGS. 20(A) to 20(D) show a method of manufacturing the RFID tag shown in FIG. 8 ;
FIGS. 21(A) to 21(D) show a method of manufacturing the RFID tag shown in FIG. 9 ;
FIGS. 22(A) to 22(D) show a method of manufacturing the RFID tag shown in FIG. 10 ;
FIGS. 23(A) to 23(C) show a method of manufacturing the RFID tag shown in FIG. 11 ; and
FIGS. 24(A) and 24(B) show a method of manufacturing the RFID tag shown in FIG. 12 .
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with respect to embodiments thereof.
FIG. 3 is a sectional view of an RFID tag according to the first embodiment of the present invention.
In FIG. 3 and other figures referred to below, constituents corresponding to those of the RFID tag described above with reference to FIG. 2 are indicated by the same reference numerals and the description for them will not be repeated. Description will be made only of points different from the above-described RFID tag. In FIG. 3 and the other figures referred to below, illustration of the adhesive 15 between the base 13 and the IC chip 11 and the base sheet 14 (see FIG. 2(B) ) that covers upper portions of the RFID tag is omitted in principle, as is that in FIG. 2 . However, a feature of the present invention described below with reference to FIG. 20 resides in an adhesive. Therefore, the adhesive is shown in FIG. 20 . Also, in the embodiments described below, the base 13 is formed of a PET and the antenna 122 is formed by using a paste prepared by blending an Ag filler with a resin material such as an epoxy resin unless otherwise specified.
In the RFID tag 1 A shown in FIG. 3 , a polyimide film 21 having holes at positions corresponding to bumps is formed on the IC chip 11 . The polyimide film 21 is slightly lower than the height of bumps 16 (thinner than bumps 16 ). When the IC chip 11 with bumps 16 and polyimide film 21 is connected to the antenna 122 , the polyimide film 21 functions as a stopper to limit sinking of the bumps 16 (see FIG. 2 (B)), thus stabilizing the tag characteristics of the RFID tag.
FIG. 4 is a sectional view of an RFID tag according to a second embodiment of the present invention.
In the RFID tag 1 B shown in FIG. 4 , a PET member 22 having holes is adhered to the base 13 . The thickness of the PET member 22 is slightly smaller than the height of the bumps 16 . When the IC chip 11 with the bumps 16 is connected to the antenna 122 , the PET member 22 functions as a stopper to limit sinking of the bumps 16 , thus stabilizing the tag characteristics of the RFID tag.
FIG. 5 is a sectional view of an RFID tag according to a third embodiment of the present invention.
In the RFID tag IC shown in FIG. 5 , a protrusion (stopper portion 23 ) slightly lower in height than the bumps 16 is formed on the base 13 side before the IC chip 11 is connected to the antenna 122 . When the IC chip 11 with the bumps 16 is connected to the antenna 122 , sinking of the bumps 16 is limited by the function of the stopper portion 23 .
FIGS. 6(A) to 6(C) show an RFID tag as an example of a modification of the third embodiment of the present invention (See FIG. 5 ). FIG. 6(A) is a sectional view, FIG. 6(B) is a plan view showing the base before the IC chip is mounted, and FIG. 6(C) is a plan view showing the base after mounting the IC chip. In FIG. 6(C) , the position of the IC chip is indicated only by the broken line.
Also in the RFID tag 1 C′ shown in FIGS. 6(A) to 6(C) , a protrusion (stopper portion 23 ) slightly lower in height than the bumps 16 is formed on the base 13 side before the IC chip 11 is connected to the antenna 122 , as is that in the case shown in FIG. 5 . When the IC chip 11 with the bumps 16 is connected to the antenna 122 , sinking of the bumps 16 is limited by the function of the stopper portion 23 . In the case of the RFID tag 1 C′ shown in FIGS. 6(A) to 6(C) , the stopper portion 23 is formed on the portion of the base 13 on which the IC chip 11 is mounted except the portions on which connections to the bumps 16 are made. That is, the stopper portion 23 extends so as to fill the almost entire region where no antenna portion exists between two ends of the antenna 122 . If the stopper portion 23 conforms to the region where no antenna pattern portion exists, it is possible to maintain the balance (attitude) of the IC chip 11 at the time of mounting of the IC chip 11 on the base 13 as well as to improve the intimate contact between the IC chip 11 and the base 13 .
FIG. 7 is a sectional view of an RFID tag according to a fourth embodiment of the present invention.
In the RFID tag 1 D shown in FIG. 7 , a plastic filler 24 having a diameter slightly smaller than the height of the bumps 16 is blended with an adhesive (not shown). When the IC chip 11 with the bumps 16 is connected to the antenna 122 , the plastic filler 24 functions as a stopper to limit sinking of the bumps 16 .
FIG. 8 is a sectional view of an RFID tag according to a fifth embodiment of the present invention.
In the RFID tag 1 E shown in FIG. 8 , a hard resin layer 25 is provided between the base 13 formed of a PET and the antenna 122 . When the IC chip 11 with the bumps 16 is connected to the antenna 122 , sinking of the bumps 16 is limited thanks to the existence of the hard resin layer 25 .
FIG. 9 is a sectional view of an RFID tag according to a sixth embodiment of the present invention.
In the RFID tag 1 F shown in FIG. 9 , a PET sheet 26 harder than the base 13 is placed between the base 13 formed of a PET and the antenna 122 . When the IC chip 11 with the bumps 16 is connected to the antenna 122 , sinking of the bumps 16 is limited thanks to the existence of the hard PET sheet 26 , as in the case of the RFID tag 1 E shown in FIG. 8 .
FIG. 10 is a sectional view of an RFID tag according to a seventh embodiment of the present invention.
In the RFID tag 1 G shown in FIG. 10 , supports 27 made of a metal are disposed on the portions of the antenna 122 on the base 13 which correspond to the positions of the bumps 16 . The bumps 16 are directly connected to the supports 27 and connected to the antenna 122 through the supports 27 . In the case of this RFID tag 1 G, sinking of the bumps 16 is prevented thanks to the existence of the supports 27 .
FIG. 11 is a sectional view of an RFID tag according to an eighth embodiment of the present invention.
In the RFID tag 1 H shown in FIG. 11 , the Ag filler filling factor of bump mount portions 122 a of the antenna 122 to be connected to the bumps 16 is increased relative to that of the portion other than the bump mount portions 122 a so that the bump mount portions 122 a are higher in hardness than the other portion, thereby limiting sinking of the bumps 16 when the antenna 122 receives the pressing force from the bumps 16 .
FIG. 12 is a sectional view of base and antenna portions of an RFID tag according to a ninth embodiment of the present invention.
Any fault due to the above-described sinking has not been considered in the conventional techniques. Thus, typically, when adopting a paste as the material of the antenna 122 , blending of a filler with the paste, e.g., blending of an Ag filler or the like with a resin material such as an epoxy resin shown in Part (A) of FIG. 12 , has been performed mainly for the purpose of giving the necessary conductivity to the paste so that the paste functions as the antenna.
In contrast, in the case of the RFID tag 1 I having the base and the antenna shown in Part (B) of FIG. 12 , a filler such as an Ag filler for giving the necessary conductivity to the paste so that the paste functions as the antenna is blended with a resin material such as an epoxy resin, and a filler 28 for giving the necessary hardness to the antenna formed of the paste, e.g., Cu, Pd or Ni is also blended with the resin material. An antenna 122 b is formed by using the paste in which such fillers are blended. In this way, sinking of the bumps 16 caused by the pressing force from the bumps 16 is prevented.
Methods of manufacturing the various RFID tags 1 A to 1 I described above will now be described.
FIGS. 13(A) to 13(C) illustrate a method of forming the bumps on the electrodes of the IC chip.
First, a thin metal wire 30 to be formed as bumps is caused to project from the tip of a jig 20 with a hole, as shown in FIG. 13(A) , and electric discharge is caused between the thin metal wire 30 and a discharge electrode 40 . A portion of the thin metal wire 30 at the tip is molten by the discharge energy to form a metal ball 31 .
Subsequently, the metal ball 31 is pressed against the electrode 111 of the IC chip 11 and ultrasonic waves are applied to the metal ball 31 through the jig 20 , as shown in FIG. 13(B) . The metal ball 31 is joined to the electrode 111 of the IC chip 11 by the ultrasonic waves. When the jig 20 is removed, the metal ball 31 and the thin metal wire 30 at the foot are torn off to form the bump in original form 32 on the electrode 111 of the IC chip 11 , as shown in FIG. 13(C) .
FIG. 14 is a diagram showing a method of leveling the bump, and FIGS. 15(A) to 15(C) are diagrams showing the bump after leveling.
After being formed on the electrode 111 of the IC chip 11 as shown in FIG. 13 , the bump in original form 32 is pressed on a flat surface of a glass plate 50 , as shown in FIG. 14 . The load for this pressing and the pressing height are selected to change the shape of the bump. That is, the bump 16 having the shape shown in FIG. 15(A) is formed in the case of low-load high-position pressing; the bump 16 having the shape shown in FIG. 15(B) is formed in the case of medium-load medium-position pressing; and the bump 16 having the shape shown in FIG. 15(C) is formed in the case of high-load low-position pressing.
FIGS. 16(A) to 16(D) show a method of manufacturing the RFID tag having the stopper formed of the polyimide film with holes shown in FIG. 3 .
The polyimide film 21 is formed on the surface of the IC chip 11 on which the electrodes 111 are provided (FIG. 16 (A)), and only portions of the polyimide film 21 corresponding to the electrodes 111 are removed by laser machining or etching, thereby forming the polyimide film 21 having holes 212 formed in correspondence with the electrodes 111 on which bumps will be formed ( FIG. 16(B) ). Thereafter, the bumps in original form 32 are formed on the electrodes 111 by the method shown in FIGS. 13(A) to 13(C) , as shown in FIG. 16(C) . Leveling is performed on the bumps in original form 32 by the method shown in FIG. 14 and FIGS. 15(A) to 15(C) to form the bumps 16 slightly higher in height than polyimide film 21 . The bumps 16 facing the base 13 and the antenna 122 are connected to each other ( FIG. 16(D) ). At this time, the polyimide film 21 functions as a stopper to limit sinking of the bumps 16 .
FIGS. 17(A) to 17(C) show a method of manufacturing the RFID tag having the stopper formed of a PET with holes as shown in FIG. 4 .
The PET member 22 with holes 221 is prepared (FIG. 17 (A)), and is applied to the base 13 on which the antenna 122 is formed, the holes 221 being aligned with the bump connection portions ( FIG. 17(B) ). The IC chip 11 is thereafter mounted ( FIG. 17(C) ). At this time, the PET member 22 functions as a stopper to prevent sinking of bumps 16 .
FIGS. 18(A) to 18(C) show a method of manufacturing the RFID tag having the stopper shown in FIG. 5 .
A film 231 made of an insulating material is formed on the surface of the base 13 on which the antenna 122 is formed ( FIG. 18(A) ). As the material of this film 231 , polyethylene, epoxy, polyester or the like for example can be used. The film 231 thereby formed has a thickness slightly smaller than the height of bumps 16 formed afterward. Unnecessary portions of the film 231 are removed by chemical etching and only a portion of the film 231 adjacent to the portions of the antenna 122 to be connected to the bumps are left, thereby forming the stopper portion 23 on the base 13 ( FIG. 18(B) ). The IC chip 11 with bumps 16 is mounted on the base 13 and the bumps 16 and the antenna 122 are connected to each other. Since the stopper portion 23 is formed so as to be slightly lower in height than the bumps 16 before connection, the bumps 16 are connected to the antenna 122 with reliability, and sinking of the bumps 16 is prevented by the function of the stopper portion 23 .
While the method of manufacturing the RFID tag according to the third embodiment shown in FIG. 5 has been described with reference to FIGS. 18(A) to 18(C) , the RFID tag shown in FIGS. 6(A) to 6(C) as an example of modification of the third embodiment can also be manufactured by forming the stopper portion 23 whose shape however is the one shown in FIG. 6(B) .
FIGS. 19(A) and 19(B) show a method of manufacturing the RFID tag including the plastic filler shown in FIG. 7 .
As shown in FIG. 19(A) , the adhesive 15 in which the plastic filler 24 is blended is applied to a portion of the base 13 on which the antenna 122 is formed. The portion of the base 13 to which the plastic filler 24 is applied is adjacent to the portions to be connected to the bumps and is defined at such a position that the filler does not spread to the portions to be connected to the bumps. This application is performed by supplying the adhesive containing the plastic filler 24 from a nozzle tip onto the base 13 .
Thereafter, the IC chip 11 with bumps 16 is mounted on the base 13 and the bumps 16 and the antenna 122 are connected to each other, as shown in FIG. 19(B) . At this time, however, since the plastic filler 24 has a diameter slightly smaller than the height of the bumps 16 , the bumps 16 are connected to the antenna 122 with reliability, and the plastic filler 24 functions as a stopper to prevent sinking of the bumps 16 .
FIGS. 20(A) to 20(D) show a method of manufacturing the RFID tag shown in FIG. 8 .
In this case, a hard resin sheet 251 is prepared ( FIG. 20(A) ) and a hard resin layer 25 is formed by adhering the hard resin sheet 251 to the base 13 by an adhesive 252 ( FIG. 20(B) ).
Thereafter, a printing master 80 in which a hole is formed as a pattern for the antenna 122 is placed on the hard resin sheet 251 , and a paste 83 provided as the material of the antenna 122 is printed by being forced into the hole of the printing master 80 with a squeegee 81 ( FIG. 20(C) ).
Thereafter, the printing master 80 for forming the protrusion is removed, followed by drying. The antenna 122 is thereby formed.
As the printing master 80 , a thin Al or SUS plate or the like having holes formed at desired positions by etching can be used.
No method has been described with respect to making of the antenna 122 in the description of the other embodiments since the technique for printing the paste is well known. However, the same method as that described above can be used to form the antenna 122 in the other embodiments.
After the antenna 122 has been printed on the hard resin layer 25 , the IC chip 11 is mounted with the bumps 16 pressed on the antenna 122 , as shown in FIG. 20(D) . At this time, sinking of the bumps 16 is prevented thanks to the existence of the hard resin layer 25 .
FIGS. 21(A) to 21(D) show a method of manufacturing the RFID tag shown in FIG. 9 .
In this case, a PET sheet 26 harder than the base 13 formed of a PET is prepared ( FIG. 21(A) ). The hard PET sheet 26 is adhered to the base 13 by the adhesive 252 ( FIG. 21(B) ). As the material of the base 13 , a polypropylene-based soft PET is used. As the hard PET sheet 26 adhered to the base 13 , a polyester or nylon sheet can be used.
The subsequent manufacturing steps are the same as those shown in FIGS. 20(C) and 20(D) . The antenna 122 is printed on the PET sheet 26 ( FIG. 21(C) ) and the IC chip 11 is mounted ( FIG. 21(D) ). At the time of this mounting, sinking of the bumps 16 is prevented thanks to the existence of the hard PET sheet 26 .
FIGS. 22(A) to 22(D) show a method of manufacturing the RFID tag shown in FIG. 10 .
In this case, after the antenna 122 has been printed on the base 13 (FIG. 22 (A)), an electroconductive adhesive or a pressure-sensitive adhesive 271 is supplied to the portion of the antenna 122 to be connected to the bumps ( FIG. 22(B) ) and the metallic supports 27 are adhered to the surface of the antenna 122 ( FIG. 22(C) ). Thereafter, the IC chip 11 is mounted so that the bumps 16 are placed on the supports 27 ( FIG. 22(D) ). At the time of this mounting, sinking of the bumps 16 is prevented thanks to the existence of the supports 27 .
FIGS. 23(A) to 23(C) show a method of manufacturing the RFID tag shown in FIG. 11 .
In this case, a printing mask 801 for printing the portion of the antenna other than the bump mount portions to be connected to the bumps is prepared and this portion is printed on the base 13 by using a squeegee 81 and a printing paste 83 in which an Ag filler is blended with a resin material such as an epoxy resin ( FIG. 23(A) ). Thereafter, a printing mask 802 for printing the bump mount portions of the antenna is prepared and the bump mount portions are printed on the base 13 by using the squeegee 81 and a printing paste 831 in which the Ag filler blending ratio is changed so that the hardness is increased in comparison with the paste 83 used for printing of the portion other than the bump mount portions ( FIG. 23(B) ). After the antenna 122 including the bump mount portions 122 a has been formed in this manner, the IC chip 11 is mounted on the base 13 ( FIG. 23(C) ). At the time of this mounting, sinking of the bumps 16 is prevented because the bump mount portions 122 a to which the bumps 16 are connected have high hardness.
FIGS. 24(A) and 24(B) show a method of manufacturing the RFID tag shown in FIG. 12 .
In this case, the antenna is printed on the base 13 by using as the material of the antenna a paste 832 in which a filter such as a Cu, Pd or Ni filler for hardening to a level high enough to effectively limit sinking of the bumps is blended with a resin material such as an epoxy resin as well as an Ag filler for giving the necessary conductivity for the antenna to the resin material ( FIG. 24(A) ). Thereafter, on the base 13 on which the hard antenna 122 b has been formed, the IC chip 11 is mounted so that the bumps 16 formed on the IC chip 11 and the antenna 122 b are connected to each other ( FIG. 24(B) ). At this time, sinking of the bumps 16 is prevented because the antenna 122 b has sufficiently high hardness. | The present invention provides a radio frequency identification (RFID) tag which exchanges information with an external device in a noncontact manner, in which a paste is used as a material for an antenna, and which is designed to prevent sinking of bumps. A stopper for limiting sinking of bumps of a circuit chip caused by a pressing force when the circuit chip is connected to an antenna is provided on the circuit chip or a base at a position adjacent to the bumps. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a vehicle having at least one crankshaft drive capable of being actuated by muscular power, in particular a bicycle.
2. The Prior Art
Various bicycle designs are known from the state of the art, whereby such bicycles are designed in such a way that riding is possible only on horizontal or slanted grounds. It is basically impossible with known bicycles to ride in the vertical direction.
SUMMARY OF THE INVENTION
It therefore an object of the present invention to design a vehicle of the type specified above in such a way to enable vertical rides.
Due to the proposed friction gripping connection between the crankset drive of the bicycle and a substantially vertically-extending strand, the bicycle can move along the strand in the vertical direction. The strand, which is preferably a rope, chain or perforated belt, is secured at its top end on a fixing point, such as a building, preferably a tower, or a bridge. If suitable buildings are not available as fixing points, the top end of the strand can be secured on a crane. The stand is either freely suspended from such a fixing point or fixed at its bottom end as well.
A strand freely suspended at its bottom end offers the rider the additional thrill of swinging while he or she is riding which, however, also makes riding that much more difficult. Particularly when participating with such a bicycle in sport competitions, a freely suspended strand means that power and endurance are important, as well as the skill of the rider.
The friction gripping connection with the crankset drive, as opposed to a cable drum, provides for constant transmission ratios between the rate of revolutions of the crankset and the riding speed throughout the entire ride, because the strand is not wound up. Therefore, basically no derailleur gear is needed on the bicycle. However, when such derailleur gear is provided, the rider can select the speed suitable for given ride conditions, and retain that speed throughout the ride. This is important because the crankset drive of the vehicle is constantly highly stressed when riding in the upward direction, which makes throw-over of the drive chain to another chain ring and thus changing gear more difficult. However, changing gears while riding becomes superfluous due to the proposed design of the bicycle.
The friction gripping connection with the strand via a driven rotary element can be realized in a particularly simple way. No transmissions are required for translating the rotary motion of the crankset drive into other types of motion. The rotary element can be mounted directly on the shaft of the crankset, so that a conventional bicycle can be adapted to the new task with minimal expenditure. However, the rotary element is preferably non-positively connected with the rear wheel of the bicycle driven by the crankset, so that power is transmitted between the crankset and the rotary element via the drive chain of the bicycle. Any variable speed gear on the bicycle and the rear wheel brake can be jointly used in this way as well. Other types of transmission, for example by toothed gears, are of course conceivable as well. However, this would increase the re-equipping cost.
Providing for a variable speed gear offers the advantage that the bicycle can be easily adapted to different power and weight conditions of the rider. For example, a heavy-set beginner requires relatively low-gear transmission in order to be able to ride up the strand. On the other hand, a well-trained athlete will prefer high-gear transmission so as to be able to ride up at a faster speed. When a variable speed gear is used, the bicycle can be used universally.
A friction-grip type connection is advantageously formed by a capstan, which permits continuous passage of the strand in a particularly simple way. A capstan is a rotary element having a diameter expanding toward both axial ends. The strand enters the capstan rear of the widening diameter and loops around the capstan at least once, and preferably two to three times. The force generated between the entering strand and the capstan leads to displacement of the windings of the strand in the direction in which it runs off. This ensures that while riding, the strand always assumes the same position in relation to the capstan. This also ensures that the strand is looped around the capstan always in the same way, thus exerting a constant frictional force on the capstan.
A particularly favorable design of the capstan has a jacket surface having a diameter that widens at both ends and at different angles. The different pitch angles of the diameter-widening zones of the jacket surface of the capstan permit favorable adaptation of the capstan to the different loads during up and down rides. This capstan is arranged in such a way that when riding up the strand, the strand enters the capstan at its flatter end, and exits from the capstan at its steeper end. When riding down, the strand accordingly enters the capstan at its stepper end. This ensures that the lateral displacement forces acting on the strand are approximately the same when riding up and down the strand, in spite of considerable varying stresses acting on the strand.
In order to safely prevent the strand from sliding from the capstan, there is preferably a guiding surface extending at the end of the capstan perpendicular to its axis. Provision can be made for such a guiding surface at both ends of the capstan. However, alternatively, it may suffice if such a guiding surface is present only on the flatter end of the capstan. This measure ensures that the capstan has an adequate outside diameter at both of its ends for safely guiding the strand without having to design the capstan with unnecessarily great length.
As an alternative to a capstan, it is also possible to form the friction gripping connection by a driving disk. Such a driving disk keeps the strand seated and clamped in a groove extending all around, and in this way ensures sufficient friction gripping interaction with the strand in spite of the lesser looping angle. A V-shaped cross section has been successfully used for the groove because the strand, due to its tensile force, penetrates the groove just deep enough to obtain an adequate friction grip. In particular, the friction of the strand does not significantly depend on the diameter of the strand, so that when a thinner strand is used, no reduction in the friction of the strand is caused that would be hazardous to the rider.
So as to increase the friction of the strand further, the circumferential groove preferably has a corrugated shape. In this way, the strand seized by the driving disk is reversed a number of times in the axial direction of the disk, so that it is pressed even more forcefully against the groove of the driving disk, finding an increased frictional surface.
Fixing or pretensioning the bottom end of the strand increases the tensile force of the strand and thus serves to further increase the friction grip of the crankset with the strand. This raises the gripping and holding safety, on the one hand, and makes it possible, on the other hand, to reduce the number of windings around the capstan. Furthermore, this measure stabilizes the strand in its position, which reduces lateral swaying of the bicycle with the strand. This simplifies riding along the strand and thus requires less skill on part of the rider.
As an alternative to a friction gripping connection, it is possible to form a positive connection by using a toothed gear engaging a chain, perforated belt, toothed belt, or toothed rack. This is slightly more costly than the friction gripping connection described above. However, a positive connection offers the special advantage that good power transmission is constantly ensured irrespective of the load, and thus regardless of which riding direction is selected. Therefore, the transmission of power between the bicycle and the strand is particularly safe and, furthermore, entirely independent of any external influences such as the weather.
Particularly when the friction gripping or positive connection between the bicycle and the strand is made on the crankset drive or rear axle of the bicycle, the problem arises that the center of gravity of the bicycle and rider is generally located above the point of engagement with the strand. The rider, therefore, is in an instable equilibrium, which requires such rider to be specially skilled in maintaining balance. So as to achieve a stable balance in this case, provision is made on the bicycle for a guide supported on the strand and extending above the center of gravity of the bicycle and rider. The top end of the guide thus forms a point of support, and the center of gravity of the system comprising the bicycle and the rider is located below this support point. The bicycle, therefore, is in a stable equilibrium, and the position of the bicycle varies only slightly around a position of balance without any action on the part of the rider. Preferably, the equilibrium is adjusted in such a way that the line of connection between the rear wheel and front wheel of the bicycle is inclined slightly upwardly.
The guide on the strand could be a roller secured on the bicycle and spaced therefrom; which seizes the strand with particularly low friction. As an alternative, it is proposed that the guide be a sliding part, as such a part can be manufactured in simpler ways as compared to a roller, and is also safer to use.
Designing the sliding part in the form of a tube is particularly safe, because the strand is guided enclosed in the tube and is thus not capable of jumping from the guide. Since a tube is inherently stable, no further retaining measures are required at its upper end, so that only the bottom of the tube needs to be secured on the frame of the bicycle. This results in a simple structure for the bicycle, so that few reconstruction measures are required to convert a conventional bicycle to one according to the invention.
Forming the tube into a curved shape permits guiding the strand around the rider in a particularly simple way, without causing any excessive friction between the strand and the tube. In addition, the tube can be lined on the inside with material having a smoothly gliding surface such as polytetrafluoroethylene, in order to further reduce friction with the strand. Furthermore, the rider is protected against the strand.
In order to avoid damage to the strand, the tube is flexible at its top end. In this way, the top end of the tube can compensate for any swaying movements of the bicycle, and thus prevent buckling of the strand. The flexible end piece ensures smooth entry of the strand into the tube and acts like a protective cable bushing, such as is known with plugs of electric cables. Buckling of the strand is a drawback not only because it may cause damage to the strand, but also in that any such kink would brake the ride, because the strand can no longer be smoothly inserted in the tube.
It is advantageous to provide a braking device on the bicycle. If the rotary element interacting with the strand is located on a wheel of the bicycle, the operating brake acting on such wheel can be applied directly. For increasing safety, it is preferred that at least one additional brake acting on the wheel of the bicycle or directly on the strand is provided. Such brake increases the safety of the rider and prevents any free fall if the operating brake of the bicycle fails. The brake device preferably acts in such a way that starting with a preset falling speed, it causes wedging on the strand, thereby retarding the falling motion. The brake device could be mounted on or in the tube.
Finally, it is preferable to equip the crankset drive with a freewheel or chain derailleur device in order to avoid forced rotation of the crankset when the bicycle is moving down the strand. This makes downward rides easier for the rider, as no pedalling is required.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.
In the drawings, wherein similar reference characters denote similar elements throughout the several views:
FIG. 1 shows a lateral view of a preferred embodiment of the invention;
FIG. 2 shows a section through a driving disk with a reversing roller;
FIG. 3 shows a section through an arrangement according to FIG. 2 along line III--III;
FIG. 4 shows an alternative design of the driving disk;
FIG. 5 shows a three-dimensional view of a capstan;
FIG. 6 shows a section through the rear axle of the bicycle, the latter being equipped with a capstan;
FIG. 7 shows a section through a capstan; and
FIG. 8 shows a section through the crankset of the bicycle with a chain derailleur device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in detail to the drawings and, in particular, FIG. 1, there is shown a bicycle 1 with a rider 2. On bicycle 1, provision is made for a crankset drive 3, which can be put into rotation by rider 2. The rotary motion of crankset 3 is transmitted to a rear wheel 5 of bicycle 1 by a drive chain 4. For such transmission, rear wheel 5 has a number of toothed rims 6 forming a change-over gear 7. It is possible in this way to adjust the transmission ratio between the rate of revolutions of crankset 3 and the rate of revolutions of rear wheel 5 in stages. Rear wheel 5 is actively connected with brake 5', which is required for a braked and thus safe ride down the strand.
A driving disk 8 is secured on rear wheel 5. The rotary motion of rear wheel 5 is directly transmitted to driving disk 8. Driving disk 8 is grippingly connected by friction with a strand 9 in the form of a rope, which extends substantially vertically. Driving disk 8 is partially looped by strand 9 within a part zone, so that strand 9 is reversed. So that the downwardly leading section of strand 9 is realigned approximately vertically downwardly, strand 9 is reversed by a reversing roller 10, which in turn is supported on bicycle 1.
In order to obtain a stable balance for bicycle 1, strand 9 is guided in a tube 11 (shown by a sectional view), with the bottom end 12 of tube 11 being secured on bicycle frame 13. On the inside, tube 11 is coated with a gliding layer consisting of polytetrafluoroethylene in order to reduce the friction with strand 9. At its top end 14, tube 11 has a flexible end piece 15, which permits tube 11 to adapt to possible swaying movements of bicycle 1 without buckling strand 9. This ensures that strand 9 is smoothly fed into tube 11. Tube 11 is curved in such a way that it guides strand 9 around rider 2, so that the top end 14 of tube 11 is located above the center of gravity "S" of bicycle 1 and rider 2. This assures stable balance of bicycle 1. Bottom end 16 of strand 9 is pretensioned by means of a weight 17 in order to increase the frictional grip between strand 9 and driving disk 8. Alternatively, strand 9 can be secured at its bottom end 16 as well, such as by a spring.
FIGS. 2 and 3 show sectional representations of driving disk 8 and reversing roller 10. Driving disk 8 is mounted on shaft 20. Shaft 20 has an axis 21 that coincides with the axis of rear wheel 5 of bicycle 1. Driving disk 8 has a V-shaped groove 22, in which strand 9 is guided with frictioned gripping. V-shaped groove 22 is made narrow, so that strand 9 rests against flanks 23 of groove 22. In this way, strand 9, in accordance with its diameter, penetrates groove 22 just deep enough to provide it with adequate friction grip on flanks 23. Strand 9 loops around driving disk 8 by 180°, and accordingly is reversed from down to up. Such reversing of strand 9 is compensated by reversing roller 10, which is not driven. Roller 10 further reverses strand 9 by 180°.
FIG. 4 shows an alternative embodiment of driving disk 8'. Driving disk 8' has a V-shaped groove 22', which is corrugated in the axial direction. Rope 9 is forced in this way to deform itself in accordance with the corrugation of groove 22'. This results in a particularly solid frictioned gripping connection between driving disk 8' and rope 9, so that the looping angle between the two can be reduced, if need be.
FIG. 5 shows a three-dimensional representation of another embodiment for forming a friction grip connection with rope 9. In this embodiment, rope 9 is looped with three windings 30 around a capstan 31, which is mounted on shaft 20 of the rear axle of the bicycle. Capstan 31 is designed with diameters expanding toward both ends 32 and 33, so that rope 9 runs upon a conical surface 34 of capstan 31. In this way, the clamping force of rope 9 causes a pushing force "F" to act on rope 9, in the direction of capstan axis 35. This is important to prevent rope 9 from being wound on end 32 of capstan 31 as capstan 31 is turning, which would reduce the number of windings 30 of rope 9.
FIG. 6 shows a sectional view with a cut through capstan 31. Capstan 31 is torsionally rigidly mounted on shaft 20 of rear bicycle wheel 4, so that capstan 31 is driven and rotated by rear wheel 5. Via a ball bearing 36, capstan 31 is supported on a support shaft 37 forming part of bicycle frame 13. Spokes 38 of rear wheel 5 are secured on capstan 31 as well.
The shape of capstan 31 is clearly shown by the half-sectional representation according to FIG. 7. Capstan 37 has a capstan jacket surface 40, the center zone of which is formed by a cylinder surface 41. The diameter of capstan jacket surface 40 widens on both sides of the cylindrical surface 41 in the form of conical surfaces 42 and 43. Conical surfaces 42 and capstan axis 35 jointly enclose a larger angle a than the opposite conical surface 43 (angle β). Capstan 31 is mounted here in such a way that rope 9, when riding the bicycle up the rope, runs up on the flatter conical surface 43, as shown particularly in FIG. 6. This way, the load acting on the rope, which is considerably higher when bicycle 1 is riding up, is compensated, so that the forces of lateral displacement "F" acting on rope 9 are about the same when riding up and down the rope. So as to ensure an adequate end diameter of capstan 31 for safe rope guidance even with the flatter conical surface 43, capstan jacket surface 40 has, at the end of conical surface 43, a guiding surface 44 extending perpendicular to capstan axis 35. Provision for such guiding surface could be made at the other end of opposite conical surface 42 as well.
FIG. 8 shows a partly sectional view of a cutout of crankset 3. Crankset 3 consists of a crank 50, on which a pedal (not shown) is supported. Crank 50 is torsionally rigidly joined with a toothed rim 51, which is partly looped by drive chain 4. Drive chain 4 can be thrown into a groove 53 by means of a chain derailleur 52, so that the active connection between crank 50 and drive chain 4 is canceled this permits riding bicycle 1 comfortably down rope 9 without putting crankset 3.
Accordingly, while only several embodiments of the present invention have been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention. | A vehicle in the form of a bicycle with a crankset drive, which is in active frictioned gripping or positive connection with a strand extending substantially vertically. The bicycle according to the invention is therefore capable of riding along the vertical strand. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2013/073001 filed Nov. 5, 2013, and claims the benefit thereof. The International Application claims the benefit of European Application No. EP12192931 filed Nov. 16, 2012. All of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The invention relates to the modification of a surface around a hole in a layer system.
BACKGROUND OF INVENTION
[0003] Layer systems are used in particular for components operated at high temperatures. These are in particular turbine blades or vanes with a metallic substrate, metallic bonding layer and ceramic thermal barrier layer.
[0004] In addition, gas turbine components in particular are cooled by a cooling medium flowing out of a cooling hole in order to cool the component on the inside or else in order to protect the component on the outside against excessively hot gases.
[0005] Holes of this type are often made after complete coating of the substrate, in which case the opening can then be a flaw or starting point for crack growth on its inner face.
SUMMARY OF INVENTION
[0006] It is therefore an object of the invention to solve the problem mentioned above.
[0007] The object is achieved by one or more recesses around the hole as claimed in the independent claim.
[0008] The dependent claims list further advantageous measures which can be combined with one another, as desired, in order to achieve further advantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIGS. 1, 2 show a cooling hole according to the prior art,
[0010] FIGS. 3-5 show exemplary embodiments of the invention,
[0011] FIG. 6 shows a turbine blade or vane,
[0012] FIG. 7 shows a combustion chamber,
[0013] FIG. 8 shows a list of superalloys.
DETAILED DESCRIPTION OF INVENTION
[0014] The description and the figures represent merely exemplary embodiments of the invention.
[0015] FIG. 1 shows a plan view of a surface 42 of a layer 10 ( FIG. 2 ) having a hole 13 , which here in particular is in the form of a film-cooling hole.
[0016] There is a contour 45 around the hole 13 on the surface 42 . The film-cooling hole 13 can have a radial bore 16 with a symmetrical or asymmetrical cross section. Depending on the application or location on the combustion chamber brick 155 ( FIG. 9 ) or the turbine blade or vane 120 , 130 ( FIG. 8 ), the film-cooling hole 13 is formed with a diffuser 19 .
[0017] The diffuser 19 constitutes a widening of the bottom portion 16 of the hole 13 ( FIG. 2 ).
[0018] FIG. 2 shows a cross section through a layer system 25 . The layer system 25 comprises a substrate 4 .
[0019] The substrate 4 is advantageously metallic and very particularly comprises nickel-based or cobalt-based superalloys.
[0020] In this respect, use is advantageously made of alloys as shown in FIG. 8 .
[0021] An outer ceramic layer 10 , which has the outermost surface 42 , is applied to the substrate 4 directly or on a metallic bonding layer 7 .
[0022] A hole 13 , which can also have a diffuser 19 on the surface 42 , is present continuously through the layer system 25 , i.e. through the layers 7 , 10 and the substrate 4 .
[0023] FIG. 3 shows, in plan view, the diffuser 19 or the hole 13 . 48 indicates the point in the interface between the ceramic layer and the substrate or the adhesion-promoting layer, whence cracks along the interface can start.
[0024] For that reason, there is a curved recess 51 which begins upstream of the hole 13 , in an overflow direction 60 , and whose ends 54 , 57 face each other, in particular approximately centrally at the level of the hole 13 or of the diffuser 19 .
[0025] The diffuser 19 is not encircled by the recess 51 .
[0026] The recess 51 is curved, advantageously tong-shaped or O-shaped. As seen in the overflow direction 60 , the ends 54 , 57 of the recess 51 also represent the end, as seen in the overflow direction 60 , of the recess 51 .
[0027] In this case, the recess 51 is round, oval or curved and can either not touch the hole 13 or the diffuser 19 ( FIG. 3 ) or touch and merge into this hole 13 , as is shown in FIG. 5 , i.e. the recess 51 is interrupted only by the hole 13 or is at a small distance 60 ′, 60 ″ from the opening of the hole 13 . In this context, small means <10% of the length of the recess 51 .
[0028] FIG. 4 shows a cross section through FIG. 2 or, respectively, also through FIG. 5 , in which 48 indicates the region of the interface between the ceramic layer and the substrate 4 or adhesion-promoting layer 7 , which region begins at the hole 13 and the recess 51 which is located downstream of the region 48 as seen in the flow direction.
[0029] The recess 51 thus runs over the hole 13 .
[0030] In the event of spalling of the TBC 10 proceeding from the cooling air hole 13 , the TBC will break off only as far as the recess 51 and a crack will not propagate beyond the recess 51 as seen in the flow direction.
[0031] Accordingly, the recess 51 extends largely over the thickness of the outermost layer 10 .
[0032] FIG. 6 shows a perspective view of a rotor blade 120 or guide vane 130 of a turbomachine, which extends along a longitudinal axis 121 .
[0033] The turbomachine may be a gas turbine of an aircraft or of a power plant for generating electricity, a steam turbine or a compressor.
[0034] The blade or vane 120 , 130 has, in succession along the longitudinal axis 121 , a securing region 400 , an adjoining blade or vane platform 403 and a main blade or vane part 406 and a blade or vane tip 415 .
[0035] As a guide vane 130 , the vane 130 may have a further platform (not shown) at its vane tip 415 .
[0036] A blade or vane root 183 , which is used to secure the rotor blades 120 , 130 to a shaft or a disk (not shown), is formed in the securing region 400 .
[0037] The blade or vane root 183 is designed, for example, in hammerhead form. Other configurations, such as a fir-tree or dovetail root, are possible.
[0038] The blade or vane 120 , 130 has a leading edge 409 and a trailing edge 412 for a medium which flows past the main blade or vane part 406 .
[0039] In the case of conventional blades or vanes 120 , 130 , by way of example solid metallic materials, in particular superalloys, are used in all regions 400 , 403 , 406 of the blade or vane 120 , 130 .
[0040] Superalloys of this type are known, for example, from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435 or WO 00/44949.
[0041] The blade or vane 120 , 130 may in this case be produced by a casting process, by means of directional solidification, by a forging process, by a milling process or combinations thereof.
[0042] Workpieces with a single-crystal structure or structures are used as components for machines which, in operation, are exposed to high mechanical, thermal and/or chemical stresses.
[0043] Single-crystal workpieces of this type are produced, for example, by directional solidification from the melt. This involves casting processes in which the liquid metallic alloy solidifies to form the single-crystal structure, i.e. the single-crystal workpiece, or solidifies directionally.
[0044] In this case, dendritic crystals are oriented along the direction of heat flow and form either a columnar crystalline grain structure (i.e. grains which run over the entire length of the workpiece and are referred to here, in accordance with the language customarily used, as directionally solidified) or a single-crystal structure, i.e. the entire workpiece consists of one single crystal. In these processes, a transition to globular (polycrystalline) solidification needs to be avoided, since non-directional growth inevitably forms transverse and longitudinal grain boundaries, which negate the favorable properties of the directionally solidified or single-crystal component.
[0045] Where the text refers in general terms to directionally solidified microstructures, this is to be understood as meaning both single crystals, which do not have any grain boundaries or at most have small-angle grain boundaries, and columnar crystal structures, which do have grain boundaries running in the longitudinal direction but do not have any transverse grain boundaries. This second form of crystalline structures is also described as directionally solidified microstructures (directionally solidified structures).
[0046] Processes of this type are known from U.S. Pat. No. 6,024,792 and EP 0 892 090 A1.
[0047] The blades or vanes 120 , 130 may likewise have coatings protecting against corrosion or oxidation e.g. (MCrAlX; M is at least one element selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), X is an active element and stands for yttrium (Y) and/or silicon and/or at least one rare earth element, or hafnium (Hf)). Alloys of this type are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1 306 454 A1.
[0048] The density is advantageously 95% of the theoretical density.
[0049] A protective aluminum oxide layer (TGO=thermally grown oxide layer) is formed on the MCrAlX layer (as an intermediate layer or as the outermost layer).
[0050] The layer advantageously has a composition Co-30Ni-28Cr-8Al-0.6Y-0.7Si or Co-28Ni-24Cr-10Al-0.6Y. In addition to these cobalt-based protective coatings, it is also advantageous to use nickel-based protective layers, such as Ni-10Cr-12A1-0.6Y-3Re or Ni-12Co-21Cr-11Al-0.4Y-2Re or Ni-25Co-17Cr-10Al-0.4Y-1.5Re.
[0051] It is also possible for a thermal barrier layer, which is advantageously the outermost layer and consists for example of ZrO 2 , Y 2 O 3 —ZrO 2 , i.e. unstabilized, partially stabilized or fully stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide, to be present on the MCrAlX.
[0052] The thermal barrier layer covers the entire MCrAlX layer.
[0053] Columnar grains are produced in the thermal barrier layer by suitable coating processes, such as for example electron beam physical vapor deposition (EB-PVD).
[0054] Other coating processes are possible, for example atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier layer may include grains that are porous or have micro-cracks or macro-cracks, in order to improve the resistance to thermal shocks. The thermal barrier layer is therefore advantageously more porous than the MCrAlX layer.
[0055] Refurbishment means that after they have been used, protective layers may have to be removed from components 120 , 130 (e.g. by sand-blasting). Then, the corrosion and/or oxidation layers and products are removed. If appropriate, cracks in the component 120 , 130 are also repaired. This is followed by recoating of the component 120 , 130 , after which the component 120 , 130 can be reused.
[0056] The blade or vane 120 , 130 may be hollow or solid in form. If the blade or vane 120 , 130 is to be cooled, it is hollow and may also have film-cooling holes 418 (indicated by dashed lines).
[0057] FIG. 9 shows a combustion chamber 110 of a gas turbine.
[0058] The combustion chamber 110 is configured, for example, as what is known as an annular combustion chamber, in which a multiplicity of burners 107 , which generate flames 156 and are arranged circumferentially around an axis of rotation 102 , open out into a common combustion chamber space 154 . For this purpose, the combustion chamber 110 overall is of annular configuration positioned around the axis of rotation 102 .
[0059] To achieve a relatively high efficiency, the combustion chamber 110 is designed for a relatively high temperature of the working medium M of approximately 1000° C. to 1600° C. To allow a relatively long service life even with these operating parameters, which are unfavorable for the materials, the combustion chamber wall 153 is provided, on its side which faces the working medium M, with an inner lining formed from heat shield elements 155 .
[0060] On the working medium side, each heat shield element 155 made from an alloy is equipped with a particularly heat-resistant protective layer (MCrAlX layer and/or ceramic coating) or is made from material that is able to withstand high temperatures (solid ceramic bricks).
[0061] These protective layers may be similar to the turbine blades or vanes, i.e. for example MCrAlX: M is at least one element selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), X is an active element and stands for yttrium (Y) and/or silicon and/or at least one rare earth element or hafnium (Hf). Alloys of this type are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1 306 454 A1.
[0062] A for example ceramic thermal barrier layer, consisting for example of ZrO 2 , Y 2 O 3 —ZrO 2 , i.e. unstabilized, partially stabilized or fully stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide, may also be present on the MCrAlX.
[0063] Columnar grains are produced in the thermal barrier layer by suitable coating processes, such as for example electron beam physical vapor deposition (EB-PVD).
[0064] Other coating processes are conceivable, for example atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier layer may include grains that are porous or have micro-cracks or macro-cracks, in order to improve the resistance to thermal shocks.
[0065] Refurbishment means that after they have been used, protective layers may have to be removed from heat shield elements 155 (e.g. by sand-blasting).
[0066] Then, the corrosion and/or oxidation layers and products are removed. If appropriate, cracks in the heat shield element 155 are also repaired. This is followed by recoating of the heat shield elements 155 , after which the heat shield elements 155 can be reused.
[0067] A cooling system may also be provided for the heat shield elements 155 and/or their holding elements, on account of the high temperatures in the interior of the combustion chamber 110 . The heat shield elements 155 are then for example hollow and may also have cooling holes (not shown) which open out into the combustion chamber space 154 .
[0068] FIG. 10 shows by way of example a partial longitudinal section through a gas turbine 100 .
[0069] In its interior, the gas turbine 100 has a rotor 103 which is mounted such that it can rotate about an axis of rotation 102 , has a shaft 101 , and is also referred to as the turbine rotor.
[0070] An intake housing 104 , a compressor 105 , a for example toroidal combustion chamber 110 , in particular an annular combustion chamber, with a plurality of coaxially arranged burners 107 , a turbine 108 and the exhaust gas housing 109 follow one another along the rotor 103 .
[0071] The annular combustion chamber 110 is in communication with a for example annular hot gas duct 111 . There, by way of example, four successive turbine stages 112 form the turbine 108 .
[0072] Each turbine stage 112 is formed for example from two blade or vane rings. As seen in the direction of flow of a working medium 113 , a guide vane row 115 is followed in the hot gas duct 111 by a row 125 formed from rotor blades 120 .
[0073] The guide vanes 130 are secured to an inner housing 138 of a stator 143 , whereas the rotor blades 120 of a row 125 are fitted on the rotor 103 , for example by means of a turbine disk 133 .
[0074] A generator (not shown) is coupled to the rotor 103 .
[0075] While the gas turbine 100 is operating, air 135 is drawn in through the intake housing 104 and compressed by the compressor 105 . The compressed air provided at the turbine end of the compressor 105 is passed to the burners 107 , where it is mixed with a fuel. The mixture is then burnt in the combustion chamber 110 , forming the working medium 113 . From there, the working medium 113 flows along the hot gas duct 111 past the guide vanes 130 and the rotor blades 120 . The working medium 113 is expanded at the rotor blades 120 , transferring its momentum, so that the rotor blades 120 drive the rotor 103 and the latter in turn drives the generator coupled to it.
[0076] While the gas turbine 100 is operating, the components which are exposed to the hot working medium 113 are subject to thermal stresses. The guide vanes 130 and rotor blades 120 of the first turbine stage 112 , as seen in the direction of flow of the working medium 113 , together with the heat shield elements which line the annular combustion chamber 110 , are subject to the highest thermal stresses.
[0077] To be able to withstand the temperatures which prevail there, they can be cooled by means of a coolant.
[0078] Substrates of the components may likewise have a directional structure, i.e. they are in single-crystal form (SX structure) or have only longitudinally oriented grains (DS structure).
[0079] By way of example, iron-based, nickel-based or cobalt-based superalloys are used as material for the components, in particular for the turbine blade or vane 120 , 130 and components of the combustion chamber 110 .
[0080] Superalloys of this type are known for example from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 Al, WO 99/67435 or WO 00/44949.
[0081] The blades or vanes 120 , 130 may likewise have coatings protecting against corrosion (MCrAlX; M is at least one element selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), X is an active element and stands for yttrium (Y) and/or silicon, scandium (Sc) and/or at least one rare earth element, or hafnium). Alloys of this type are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1 306 454 A1.
[0082] A thermal barrier layer, consisting for example of ZrO 2 , Y 2 O 3 —ZrO 2 , i.e. unstabilized, partially stabilized or fully stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide, may also be present on the MCrAlX.
[0083] Columnar grains are produced in the thermal barrier layer by suitable coating processes, such as for example electron beam physical vapor deposition (EB-PVD).
[0084] The guide vane 130 has a guide vane root (not shown here), which faces the inner housing 138 of the turbine 108 , and a guide vane head which is at the opposite end from the guide vane root. The guide vane head faces the rotor 103 and is fixed to a securing ring 140 of the stator 143 . | A layer system is provided having a substrate, an outermost layer with a surface, at least one hole at least in the outermost layer, wherein in the vicinity around the hole or directly adjoining a boundary line of the hole, at least one, not closed extending recess is present in the surface of the outermost layer in which the recess is curved and its ends face each other. Through the use of depressions in a layer, spalling within the interfaces through the layers is prevented. | 5 |
BACKGROUND OF THE INVENTION
In many stairway structures it is desirable to provide for replaceable stair treads and for supporting the stair treads securely. Proper support of glass stair treads, for example, has been a somewhat vexatious problem in the art of stair tread support systems. The support system should, of course, avoid concentration of support forces on the stair tread, securely retain the stair tread in its working position, preferably offer some cushioning for reacting forces exerted on the stair tread when being traversed by pedestrians, and minimize noise transmission or amplification from the stair tread to the stairway structure. It is to meet the desiderata and needs of stair tread support systems that the present invention has been developed.
SUMMARY OF THE INVENTION
The present invention provides an improved stair tread support system and stair tread support member.
In accordance with one aspect of the present invention, opposed stair tread support members are provided which are particularly adapted to releasably support generally planar stair treads in a manner which suitably secures the stair tread in a fixed working position while also providing for easy removal and replacement or repair of the stair treads, if and when needed. In particular, the stair tread support members are adapted for supporting glass stair treads, for example.
In accordance with yet a further aspect of the present invention, a stair tread support member is provided which includes a generally planar plate-like base part, a first integral transverse support flange and a second support flange disposed spaced from the first flange, and also integrally formed with or detachably connected to the base part. A stair tread cushioning member is adapted for placement on the first flange and engageable with the base part and the second flange. The second flange may also be formed as a separate part releasably securable to the base part by mechanical fasteners.
Still further, in accordance with the invention, a stair tread support member is provided including one or more threaded fasteners threadedly engaged with a second flange and with a tread member or a cushioning member interposed the tread member and the fastener for securing the tread member to the tread support member. The tread support member may further include an elongated removable trim cap for covering the heads and/or threaded openings for receiving the tread or flange retaining fasteners. Opposed removable retainers may be releasably secured to the tread support member at opposite ends thereof.
Those skilled in the art will further appreciate the above-mentioned advantages and superior features of the invention together with other important aspects thereof upon reading the detailed description which follows in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a portion of a stairway which includes a stair tread support system and support members thereof in accordance with the invention;
FIG. 2 is a perspective view of one preferred embodiment of a stair tread support member in accordance with the invention;
FIG. 3 is an exploded transverse view of the stair tread support member shown in FIG. 2 , and including a tread cushioning member;
FIG. 4 is a detail view showing the tread support member illustrated in FIG. 3 in assembly with and securing a stair tread;
FIG. 5 is an exploded transverse view of an alternate embodiment of a stair tread support member in accordance with the invention; and
FIG. 6 is a detail view showing the stair tread support member lustrated in FIG. 5 in assembly with and securing a stair tread.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the description which follows like parts are marked throughout the specification and drawing with the same reference numerals, respectively. The drawing figures may not be to scale and certain elements may be shown in generalized or somewhat schematic form in the interest of clarity and conciseness.
Referring to FIG. 1 , there is illustrated a portion of a stairway, generally designated by the numeral 10 , including a stair tread support system in accordance with the invention. Stairway 10 includes opposed parallel extending stringer members 12 and 14 which are characterized as generally planar members in the embodiment illustrated. Stairway 10 also includes spaced apart tread members 16 which are also characterized as generally planar, rectangular members and, in the embodiment shown, are preferably formed of glass or a similar transparent or translucent material of aesthetically pleasing quality. The tread members may each be a unitary member or “built-up” of plural laminated plate-like members. The tread members 16 are supported between and on the stringers 12 and 14 by an improved support system including opposed tread support members 18 , respectively. The tread support members 18 are of identical and symmetrical configuration and may be used on either of stringers 12 or 14 .
Referring now to FIGS. 2 and 3 , there is illustrated in further detail one of the tread support members 18 of the present invention. Tread support member 18 includes a generally planar, elongated base part 20 delimited by a lower transverse end 22 , an upper transverse end 24 and opposed longitudinal end walls 26 and 28 . An integral transverse support flange 30 projects normal to the inwardly facing planar surface 20 a of base part 20 and is reinforced by a longitudinally extending strut part 32 which is also, preferably, formed integral with the flange 30 and the base part 20 . Flange 30 is of a greater width than a second flange also integrally formed with the base part 20 and generally designated by the numeral 34 . Flange 34 is spaced from flange 30 and both flange 34 and flange 30 are provided with opposed facing planar parallel surfaces 34 a and 30 a , respectively. Flange 34 is provided with a longitudinally extending upward facing so-called T-shaped or dovetail-shaped slot 36 which opens to the end walls 26 and 28 of the tread support member. Flange 34 is also provided with spaced apart tread fastener receiving holes or openings 38 , one shown in FIG. 3 , each for receiving a sockethead type thread fastener 39 also as shown in FIG. 3 . Threaded opening 38 extends between surface 34 a and a surface 34 b delimiting the upper surface of flange 34 .
Referring further to FIGS. 2 and 3 , a lower portion 20 k of base part 20 is provided with spaced apart fastener receiving openings 20 m for securing the tread support member 18 to one of the stringers 12 and 14 using conventional mechanical fasteners, not shown. Still further, as shown in FIG. 3 , the tread support system of the invention includes a somewhat “L” shaped tread cushioning member 40 including a base part 40 a and an upstanding leg part 40 b integrally formed with the base part 40 a and extending at a right angle thereto. A separate cushioning member cap part 42 may form part of the cushioning member 40 but is preferably formed as a separate member. Stair tread cushioning members 40 and 42 are preferably formed of a clear silicone composition.
Referring still further to FIGS. 2 and 3 , an elongated trim cap 44 is provided for the flange 34 and includes a T-shaped or dovetail base 46 and a generally planar head portion 48 . Cap 44 may be inserted in the slot 36 from one end wall 26 or the other end wall 28 of the tread support member 18 once the fasteners 39 have been inserted in their working positions, see FIG. 4 . As shown in FIG. 2 , opposed, removable tread retainer plates 41 may be releasably connected to tread support member 18 by suitable fasteners 45 , two shown, for securing the plates to end walls 26 and 28 , respectively.
Referring further to FIG. 4 , there is illustrated the tread support member 18 completely assembled and also supporting one end of a tread member, such as the tread member 16 . Tread member 16 may be a single thickness plate-like member or a laminated member made up of plural plate-like members 16 a , 16 b and 16 c , as illustrated. Thanks to the cushioning member 40 , 42 , the fasteners 39 and the configuration of the flanges 30 and 34 , the tread member 16 may be securely fastened to the tread support members 18 at opposite ends, FIG. 1 , while at the same time each cushioning member 40 , 42 minimizes shock loading of its associated tread support member and minimizes the transmission of vibrations from the tread member to the remainder of the stairway system. It will be appreciated by those skilled in the art that the tread members 16 may be easily replaced when needed by removal of the cap 44 for each tread support member 18 , loosening or removal of the fasteners 39 and then sliding the ends of the tread members out of the slots formed between the flanges 30 and 34 . Tread support members 18 may be formed of extruded metal or plastic, for example, and provided in aesthetically pleasing colors or surface finish and the tread support members 18 may also be easily replaced on the stringers 12 and 14 , if desired.
Referring now to FIGS. 5 and 6 , there is illustrated another preferred embodiment of a stair tread support member in accordance with the invention. A stair tread support member 18 a is shown in FIG. 5 in an exploded transverse or end view corresponding to FIG. 3 in some respects. The tread support member 18 a includes a generally planar base part 21 delimited by an upper edge 24 a and a lower edge 22 a . An integral flange 30 extends transversely to the base part 21 and defines surface 30 a normal to a surface 21 a delimiting an upper portion of the base part of the tread support member 18 A. A difference in the configuration of the tread support member 18 a , as compared to the tread support member 18 , is that an upper portion of the base part 21 is of a greater width than that of the member 18 in order to accommodate one or more fastener receiving openings 38 b , and a separable upper flange 35 which is provided with an elongated T-shaped or dovetail slot 36 but is also provided with one or more fastener receiving openings 35 a to receive a threaded fastener 39 a , preferably a sockethead machine screw, operable to secure the upper flange 35 to the base part 21 and to also operate to secure a tread between a lower surface 35 b of separable upper flange 35 and the surface 30 a of integral flange 30 . A slightly modified cushioning member 40 d is provided with opposed integrally joined right angle oriented parts 40 e and 40 f . A separate cushioning strip 43 is provided corresponding to the strip 42 .
As shown in FIG. 6 , the tread support member 18 a is operable to secure a single or laminated tread, such as the tread 16 , by placing the cushioning member 40 d on surface 30 a and bearing against surface 21 a whereby the tread 16 may be securely clamped to the member 18 a by the separable flange 35 using the recessed or sockethead screws 39 a , one shown in FIG. 6 . The cap 44 is disposed in slot 36 of separable flange 35 once the recessed sockethead screws 39 a are disposed in their counterbored receiving openings 35 a , as illustrated. Of course, the length of the tread 16 may require to be shortened slightly or the span between the stringers 12 and 14 may require adjustment for use of the tread support members 18 a taking into consideration the thickness of the upper part of the base member 21 which defines the surface 21 a.
The construction and operation of the tread support system and the tread support members 18 and 18 a of the present invention are believed to be readily understandable to those skilled in the art based on the foregoing description. Conventional engineering materials may be used to provide the support members 18 and 18 a , as well as the cushioning members 40 , 40 d , 42 and 43 , as previously mentioned. Although preferred embodiments of the invention have been described in detail, those skilled in the art will recognize that various substitutions and modifications may be made without departing from the scope and spirit of the appended claims. | A stair tread support member for releasably supporting generally planar stair tread members including stair tread members made of glass or other transparent material includes a general planar base part adapted to be supported on a stairway stinger. The tread support member includes spaced apart flanges forming a channel shaped slot for receiving and supporting a stair tread member. A cushioning member may be interposed the support flanges and the stair tread member. Removable threaded fasteners are engageable with the second flange for retaining the stair treads secured to the tread support member. An elongated cap fits in a slot in the second flange and covers the fasteners. | 4 |
RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. Non-Provisional patent application Ser. No. 13/300,805, filed Nov. 21, 2011, which claims the benefit of U.S. Provisional Application Ser. No. 61/419,362, filed Dec. 3, 2010, the disclosure of which is hereby incorporated in its entirety herein by reference
FIELD OF THE INVENTION
[0002] The present invention relates to novel oxime derivatives, processes for preparing them, pharmaceutical compositions containing them and their use as pharmaceuticals, as modulators of sphingosine-1-phosphate receptors. The invention relates specifically to the use of these compounds and their pharmaceutical compositions to treat disorders associated with sphingosine-1-phosphate (S1P) receptor modulation.
BACKGROUND OF THE INVENTION
[0003] Sphingosine-1 phosphate is stored in relatively high concentrations in human platelets, which lack the enzymes responsible for its catabolism, and it is released into the blood stream upon activation of physiological stimuli, such as growth factors, cytokines, and receptor agonists and antigens. It may also have a critical role in platelet aggregation and thrombosis and could aggravate cardiovascular diseases. On the other hand the relatively high concentration of the metabolite in high-density lipoproteins (HDL) may have beneficial implications for atherogenesis. For example, there are recent suggestions that sphingosine-1-phosphate, together with other lysolipids such as sphingosylphosphorylcholine and lysosulfatide, are responsible for the beneficial clinical effects of HDL by stimulating the production of the potent antiatherogenic signaling molecule nitric oxide by the vascular endothelium. In addition, like lysophosphatidic acid, it is a marker for certain types of cancer, and there is evidence that its role in cell division or proliferation may have an influence on the development of cancers. These are currently topics that are attracting great interest amongst medical researchers, and the potential for therapeutic intervention in sphingosine-1-phosphate metabolism is under active investigation.
SUMMARY OF THE INVENTION
[0004] A group of novel oxime derivatives, which are potent and selective sphingosine-1-phosphate modulators has been discovered. As such, the compounds described herein are useful in treating a wide variety of disorders associated with modulation of sphingosine-1-phosphate receptors. The term “modulator” as used herein, includes but is not limited to: receptor agonist, antagonist, inverse agonist, inverse antagonist, partial agonist, partial antagonist.
[0005] This invention describes compounds of Formula I, which have sphingosine-1-phosphate receptor biological activity. The compounds in accordance with the present invention are thus of use in medicine, for example in the treatment of humans with diseases and conditions that are alleviated by S1P modulation.
[0006] In one aspect, the invention provides a compound having Formula I or a pharmaceutically acceptable salt thereof or stereoisomeric forms thereof, or the geometrical isomers, enantiomers, diastereoisomers, tautomers, zwitterions and pharmaceutically acceptable salts thereof:
[0000]
[0000] wherein:
A is C 6-10 aryl, heterocycle, C 3-8 cycloalkyl or C 3-8 cycloalkenyl;
B is C 6-10 aryl, heterocycle, C 3-8 cycloalkyl or C 3-8 cycloalkenyl;
R 1 is H, halogen, —OC 1-8 alkyl, C 1-8 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 2 is H, halogen, —OC 1-8 alkyl, C 1-8 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 3 is H, halogen, —OC 1-8 alkyl, C 1-8 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 4 is H, halogen, —OC 1-8 alkyl, C 1-8 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 5 is H, halogen, —OC 1-8 alkyl, C 1-8 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 6 is H, halogen, —OC 1-8 alkyl, C 1-8 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 7 is H, halogen, —OC 1-8 alkyl, C 1-8 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 8 is halogen, —OC 1-8 alkyl, C 1-8 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
L 1 is O, C(O), S, NH or CH 2 ;
R 9 is O, S or CH 2 ;
[0007] R 10 is H or C 1-8 alkyl;
L 2 is CHR 16 , O, S, NR 17 or —C(O)—;
[0008] D is a group of formula
[0000]
[0000] “*” indicating the point of attachment to the rest of the molecule;
R 11 is H, OPO 3 H 2 , carboxylic acid, PO 3 H 2 , C 1-8 alkyl, —S(O) 2 H, —P(O)MeOH, —P(O)(H)OH or OR 12 ;
R 12 is H or C 1-8 alkyl;
a is 0, 1 or 2;
b is 0 or 1;
c is 0, 1, 2 or 3;
R 13 is H, C 1-8 alkyl;
R 14 is H or C 1-8 alkyl; and
R 15 is H or C 1-8 alkyl;
R 16 is H, OH or C 1-8 alkyl; and
R 17 is H or C 1-8 alkyl.
[0009] In another aspect, the invention provides a compound having Formula I wherein L 1 is O, C(O), S or NH.
[0010] In another aspect, the invention provides a compound having Formula I wherein L 1 is O.
[0011] In another aspect, the invention provides a compound having Formula I wherein L 1 is S.
[0012] In another aspect, the invention provides a compound having Formula I wherein L 1 is CH 2 .
[0000] In another aspect, the invention provides a compound having Formula I wherein D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule.
In another aspect, the invention provides a compound having Formula I wherein D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule.
[0013] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0014] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0015] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0016] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0000] R 1 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 2 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 3 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 4 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 5 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 6 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 7 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 8 is halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
L 1 is O, C(O), S, NH or CH 2 ;
R 9 is O, S or CH 2 ;
[0017] R 10 is H or C 1-6 alkyl;
L 2 is CHR 16 , O, S, NR 17 or —C(O)—;
[0018] D is a group of formula
[0000]
[0000] “*” indicating the point of attachment to the rest of the molecule;
R 11 is H, OPO 3 H 2 , carboxylic acid, PO 3 H 2 , C 1-6 alkyl, —S(O) 2 H, —P(O)MeOH, —P(O)(H)OH or OR 12 ;
R 12 is H or C 1-6 alkyl;
a is 0, 1 or 2;
b is 0 or 1;
c is 0, 1, 2 or 3;
R 13 is H, C 1-6 alkyl;
R 14 is H or C 1-6 alkyl; and
R 15 is H or C 1-6 alkyl;
R 16 is H, OH or C 1-6 alkyl; and
R 17 is H or C 1-6 alkyl.
[0019] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0000] R 1 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 2 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 3 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 4 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 5 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 6 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 7 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 8 is halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
L 1 is CH 2 ;
R 9 is O, S or CH 2 ;
[0020] R 10 is H or C 1-6 alkyl;
L 2 is CHR 16 , O, S, NR 17 or —C(O)—;
[0021] D is a group of formula
[0000]
[0000] “*” indicating the point of attachment to the rest of the molecule;
R 11 is H, OPO 3 H 2 , carboxylic acid, PO 3 H 2 , C 1-6 alkyl, —S(O) 2 H, —P(O)MeOH, —P(O)(H)OH or OR 12 ;
R 12 is H or C 1-6 alkyl;
a is 0, 1 or 2;
b is 0 or 1;
c is 0, 1, 2 or 3;
R 13 is H, C 1-6 alkyl;
R 14 is H or C 1-6 alkyl; and
R 15 is H or C 1-6 alkyl;
R 16 is H, OH or C 1-6 alkyl; and
R 17 is H or C 1-6 alkyl.
[0022] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0000] R 1 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 2 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 3 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 4 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 5 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 6 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 7 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 8 is halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
L 1 is O, S or CH 2 ;
R 9 is O, S or CH 2 ;
[0023] R 10 is H or C 1-6 alkyl;
L 2 is CHR 16 , O, S, NR 17 or —C(O)—;
[0024] D is a group of formula
[0000]
[0000] “*” indicating the point of attachment to the rest of the molecule;
R 11 is H, OPO 3 H 2 , carboxylic acid, PO 3 H 2 , C 1-6 alkyl, —S(O) 2 H, —P(O)MeOH, —P(O)(H)OH or OR 12 ;
R 12 is H or C 1-6 alkyl;
a is 0, 1 or 2;
b is 0 or 1;
c is 0, 1, 2 or 3;
R 13 is H, C 1-6 alkyl;
R 14 is H or C 1-6 alkyl; and
R 15 is H or C 1-6 alkyl;
R 16 is H, OH or C 1-6 alkyl; and
R 17 is H or C 1-6 alkyl.
[0025] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0026] R 1 is H, C 1-6 alkyl or halogen;
[0027] R 2 is H, C 1-6 alkyl or halogen;
[0028] R 3 is H, C 1-6 alkyl or halogen;
[0029] R 4 is H or C 1-6 alkyl,
[0030] R 5 is H or C 1-6 alkyl;
[0031] R 6 is H or C 1-6 alkyl;
[0032] R 7 is H;
[0033] a is 0;
[0034] L 1 is O, S or CH 2 ;
[0035] R 9 is CH 2 ;
R 10 is H;
L 2 is CHR 16 ;
[0036] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule;
a is 0;
b is 1;
c is 0 or 1;
[0037] R 11 is carboxylic acid or PO 3 H 2 ; and
R 16 is H.
[0038] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0000] R 1 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 2 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 3 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 4 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 5 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 6 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 7 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 8 is halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
L 1 is CH 2 ;
R 9 is O, S or CH 2 ;
[0039] R 10 is H or C 1-6 alkyl;
L 2 is CHR 16 , O, S, NR 17 or —C(O)—;
[0040] D is a group of formula
[0000]
[0000] “*” indicating the point of attachment to the rest of the molecule;
R 11 is H, OPO 3 H 2 , carboxylic acid, PO 3 H 2 , C 1-6 alkyl, —S(O) 2 H, —P(O)MeOH, —P(O)(H)OH or OR 12 ;
R 12 is H or C 1-6 alkyl;
a is 0, 1 or 2;
b is 0 or 1;
c is 0, 1, 2 or 3;
R 13 is H, C 1-6 alkyl;
R 14 is H or C 1-6 alkyl; and
R 15 is H or C 1-6 alkyl;
R 16 is H, OH or C 1-6 alkyl; and
R 17 is H or C 1-6 alkyl.
[0041] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0000] R 1 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 2 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 3 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 4 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 5 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 6 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 7 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 8 is halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
L 1 is CH 2 ;
R 9 is O, S or CH 2 ;
[0042] R 10 is H or C 1-6 alkyl;
L 2 is CHR 16 , O, S, NR 17 or —C(O)—;
[0043] D is a group of formula
[0000]
[0000] “*” indicating the point of attachment to the rest of the molecule;
R 11 is H, OPO 3 H 2 , carboxylic acid, PO 3 H 2 , C 1-6 alkyl, —S(O) 2 H, —P(O)MeOH, —P(O)(H)OH or OR 12 ;
R 12 is H or C 1-6 alkyl;
a is 0, 1 or 2;
b is 0 or 1;
c is 0, 1, 2 or 3;
R 13 is H, C 1-6 alkyl;
R 14 is H or C 1-6 alkyl; and
R 15 is H or C 1-6 alkyl;
R 16 is H, OH or C 1-6 alkyl; and
R 17 is H or C 1-6 alkyl.
[0044] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0000] R 1 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 2 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 3 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 4 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 5 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 6 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 7 is H, halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
R 8 is halogen, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)R 13 , NR 14 R 15 or hydroxyl;
L 1 is O, C(O), S or NH;
R 9 is O, S or CH 2 ;
[0045] R 10 is H or C 1-6 alkyl;
L 2 is CHR 16 , O, S, NR 17 or —C(O)—;
[0046] D is a group of formula
[0000]
[0000] “*” indicating the point of attachment to the rest of the molecule;
R 11 is H, OPO 3 H 2 , carboxylic acid, PO 3 H 2 , C 1-6 alkyl, —S(O) 2 H, —P(O)MeOH, —P(O)(H)OH or OR 12 ;
R 12 is H or C 1-6 alkyl;
a is 0, 1 or 2;
b is 0 or 1;
c is 0, 1, 2 or 3;
R 13 is H, C 1-6 alkyl;
R 14 is H or C 1-6 alkyl; and
R 15 is H or C 1-6 alkyl;
R 16 is H, OH or C 1-6 alkyl; and
R 17 is H or C 1-6 alkyl.
[0047] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0048] R 1 is H, C 1-6 alkyl or halogen;
[0049] R 2 is H, C 1-6 alkyl or halogen;
[0050] R 3 is H, C 1-6 alkyl or halogen;
[0051] R 4 is H or C 1-6 alkyl,
[0052] R 5 is H or C 1-6 alkyl;
[0053] R 6 is H or C 1-6 alkyl;
[0054] R 7 is H;
[0055] L 1 is O, CH 2 , S or NH;
[0056] R 9 is CH 2 ;
R 10 is H;
L 2 is CHR 16 ;
[0057] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule;
a is 0;
b is 1;
c is 0 or 1;
[0058] R 11 is carboxylic acid or PO 3 H 2 ; and
R 16 is H.
[0059] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0060] R 1 is H, C 1-6 alkyl or halogen;
[0061] R 2 is H, C 1-6 alkyl or halogen;
[0062] R 3 is H, C 1-6 alkyl or halogen;
[0063] R 4 is H or C 1-6 alkyl,
[0064] R 5 is H or C 1-6 alkyl;
[0065] R 6 is H or C 1-6 alkyl;
[0066] R 7 is H;
[0067] a is 0;
[0068] L 1 is O, S or NH;
[0069] R 9 is CH 2 ;
R 10 is H;
L 2 is CHR 16 ;
[0070] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule;
a is 0;
b is 1;
c is 0 or 1;
[0071] R 11 is carboxylic acid or PO 3 H 2 ; and
R 16 is H.
[0072] In another embodiment, the invention provides a compound having Formula I wherein:
[0000]
[0073] R 1 is H, C 1-6 alkyl or halogen;
[0074] R 2 is H, C 1-6 alkyl or halogen;
[0075] R 3 is H, C 1-6 alkyl or halogen;
[0076] R 4 is H or C 1-6 alkyl,
[0077] R 5 is H or C 1-6 alkyl;
[0078] R 6 is H or C 1-6 alkyl;
[0079] R 7 is H;
[0080] L 1 is CH 2 ;
[0081] R 9 is CH 2 ;
R 10 is H;
L 2 is CHR 16 ;
[0082] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule;
a is 0;
b is 1;
c is 0 or 1;
[0083] R 11 is carboxylic acid or PO 3 H 2 ; and
R 16 is H.
[0084] In another embodiment, the invention provides a compound having Formula I wherein:
[0000]
[0085] R 1 is H, C 1-6 alkyl or halogen;
[0086] R 2 is H, C 1-6 alkyl or halogen;
[0087] R 3 is H, C 1-6 alkyl or halogen;
[0088] R 4 is H or C 1-6 alkyl,
[0089] R 5 is H or C 1-6 alkyl;
[0090] R 6 is H or C 1-6 alkyl;
[0091] R 7 is H;
[0092] L 1 is CH 2 ;
[0093] R 9 is CH 2 ;
R 10 is H;
L 2 is CHR 16 ;
[0094] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule;
a is 0;
b is 1;
c is 0 or 1;
[0095] R 11 is carboxylic acid or PO 3 H 2 ; and
R 16 is H.
[0096] In another embodiment, the invention provides a compound having Formula I wherein:
[0000]
[0097] R 1 is H, C 1-6 alkyl or halogen;
[0098] R 2 is H, C 1-6 alkyl or halogen;
[0099] R 3 is H, C 1-6 alkyl or halogen;
[0100] R 4 is H or C 1-6 alkyl,
[0101] R 5 is H or C 1-6 alkyl;
[0102] R 6 is H or C 1-6 alkyl;
[0103] R 7 is H;
[0104] L 1 is CH 2 ;
[0105] R 9 is CH 2 ;
R 10 is H;
L 2 is CHR 16 ;
[0106] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule;
a is 0;
b is 1;
c is 0 or 1;
[0107] R 11 is carboxylic acid or PO 3 H 2 ; and
R 16 is H.
[0108] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0109] R 1 is H, C 1-6 alkyl or halogen;
[0110] R 2 is H, C 1-6 alkyl or halogen;
[0111] R 3 is H, C 1-6 alkyl or halogen;
[0112] R 4 is H or C 1-6 alkyl,
[0113] R 5 is H or C 1-6 alkyl;
[0114] R 6 is H or C 1-6 alkyl;
[0115] R 7 is H;
[0116] L 1 is O or S;
[0117] R 9 is CH 2 ;
R 10 is H;
L 2 is CHR 16 ;
[0118] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule;
a is 0;
b is 1;
c is 0 or 1;
[0119] R 11 is carboxylic acid or PO 3 H 2 ; and
R 16 is H.
[0120] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0121] R 1 is H, C 1-6 alkyl or halogen;
[0122] R 2 is H, C 1-6 alkyl or halogen;
[0123] R 3 is H, C 1-6 alkyl or halogen;
[0124] R 4 is H or C 1-6 alkyl,
[0125] R 5 is H or C 1-6 alkyl;
[0126] R 6 is H or C 1-6 alkyl;
[0127] R 7 is H;
[0128] L 1 is O;
[0129] R 9 is CH 2 ;
R 10 is H;
L 2 is CHR 16 ;
[0130] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule;
a is 0;
b is 1;
c is 0 or 1;
[0131] R 11 is carboxylic acid or PO 3 H 2 ; and
R 16 is H.
[0132] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0133] R 1 is H, C 1-6 alkyl or halogen;
[0134] R 2 is H, C 1-6 alkyl or halogen;
[0135] R 3 is H, C 1-6 alkyl or halogen;
[0136] R 4 is H or C 1-6 alkyl,
[0137] R 5 is H or C 1-6 alkyl;
[0138] R 6 is H or C 1-6 alkyl;
[0139] R 7 is H;
[0140] L 1 is O;
[0141] R 9 is CH 2 ;
R 10 is H;
L 2 is CHR 16 ;
[0142] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule;
a is 0;
b is 1;
c is 0 or 1;
[0143] R 11 is carboxylic acid or PO 3 H 2 ; and
R 16 is H.
[0144] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0145] R 1 is H, C 1-6 alkyl or halogen;
[0146] R 2 is H, C 1-6 alkyl or halogen;
[0147] R 3 is H, C 1-6 alkyl or halogen;
[0148] R 4 is H or C 1-6 alkyl,
[0149] R 5 is H or C 1-6 alkyl;
[0150] R 6 is H or C 1-6 alkyl;
[0151] R 7 is H;
[0152] L 1 is O;
[0153] R 9 is CH 2 ;
R 10 is H;
L 2 is CHR 16 ;
[0154] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule;
a is 0;
b is 1;
c is 0 or 1;
[0155] R 11 is carboxylic acid or PO 3 H 2 ; and
R 16 is H.
[0156] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0157] R 1 is H, C 1-6 alkyl or halogen;
[0158] R 2 is H, C 1-6 alkyl or halogen;
[0159] R 3 is H, C 1-6 alkyl or halogen;
[0160] R 4 is H or C 1-6 alkyl,
[0161] R 5 is H or C 1-6 alkyl;
[0162] R 6 is H or C 1-6 alkyl;
[0163] R 7 is H;
[0164] L 1 is S;
[0165] R 9 is CH 2 ;
R 10 is H;
L 2 is CHR 16 ;
[0166] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule;
a is 0;
b is 1;
c is 0 or 1;
[0167] R 11 is carboxylic acid or PO 3 H 2 ; and
R 16 is H.
[0168] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0169] R 1 is H, C 1-6 alkyl or halogen;
[0170] R 2 is H, C 1-6 alkyl or halogen;
[0171] R 3 is H, C 1-6 alkyl or halogen;
[0172] R 4 is H or C 1-6 alkyl,
[0173] R 5 is H or C 1-6 alkyl;
[0174] R 6 is H or C 1-6 alkyl;
[0175] R 7 is H;
[0176] L 1 is S;
[0177] R 9 is CH 2 ;
R 10 is H;
L 2 is CHR 16 ;
[0178] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule;
a is 0;
b is 1;
c is 0 or 1;
[0179] R 11 is carboxylic acid or PO 3 H 2 ; and
R 16 is H.
[0180] In another aspect, the invention provides a compound having Formula I wherein
[0000]
[0181] R 1 is H, chloro, methyl or fluoro;
[0182] R 2 is H, chloro, methyl or fluoro;
[0183] R 3 is H, chloro, methyl or fluoro;
[0184] R 4 is H or methyl;
[0185] R 5 is H or methyl;
[0186] R 6 is H or methyl;
[0187] R 7 is H;
[0188] L 1 is S;
[0189] R 9 is CH 2 ;
R 10 is H;
L 2 is CHR 16 ;
[0190] a is 0;
b is 1;
c is 0 or 1; and
R 16 is H; and
[0191] R 11 is carboxylic acid or PO 3 H 2 ; and
[0000] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule.
[0192] In another embodiment, the invention provides a compound having Formula I wherein:
[0000]
[0193] R 1 is chloro, methyl or fluoro;
[0194] R 2 is H;
[0195] R 3 is H or fluoro;
[0196] R 4 is methyl;
[0197] R 5 is methyl;
[0198] R 6 is H;
[0199] R 7 is H;
[0200] a is 0;
[0201] R 9 is CH 2 ;
[0202] R 10 is H;
L 1 is CH 2 ;
L 2 is CHR 16 ;
[0203] a is 0;
b is 1;
c is 0 or 1; and
R 16 is H; and
[0204] R 11 is carboxylic acid or PO 3 H 2 ; and
[0000] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule.
[0205] In another embodiment, the invention provides a compound having Formula I wherein:
[0000]
[0206] R 1 is chloro or methyl;
[0207] R 2 is H;
[0208] R 3 is H;
[0209] R 4 is methyl;
[0210] R 5 is methyl;
[0211] R 6 is H;
[0212] R 7 is H;
[0213] a is 0;
[0214] R 9 is CH 2 ;
[0215] R 10 is H;
L 1 is CH 2 ;
L 2 is CHR 16 ;
[0216] a is 0;
b is 1;
c is 0 or 1; and
R 16 is H; and
[0217] R 11 is carboxylic acid or PO 3 H 2 ; and
[0000] D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule.
[0218] In another embodiment, the invention provides a compound having Formula I wherein:
[0000]
[0219] R 1 is chloro or fluoro;
[0220] R 2 is H;
[0221] R 3 is H or fluoro;
[0222] R 4 is methyl;
[0223] R 5 is methyl;
[0224] R 6 is H;
[0225] R 7 is H;
[0226] R 9 is CH 2 ;
[0227] R 10 is H;
L 1 is CH 2 ;
L 2 is CHR 16 ;
[0228] a is 0;
b is 1;
c is 0 or 1; and
R 16 is H; and
[0229] R 11 is carboxylic acid or PO 3 H 2 ; and
D is a group of formula
[0000]
[0000] “*” indicates the point of attachment to the rest of the molecule.
[0230] The term “alkyl”, as used herein, refers to saturated, monovalent or divalent hydrocarbon moieties having linear or branched moieties or combinations thereof and containing 1 to 8 carbon atoms. One methylene (—CH 2 —) group, of the alkyl can be replaced by oxygen, sulfur, sulfoxide, nitrogen, carbonyl, carboxyl, sulfonyl, or by a divalent C 3-8 cycloalkyl. Alkyl groups can be substituted by halogen, hydroxyl, cycloalkyl, amino, non-aromatic heterocycles, carboxylic acid, phosphonic acid groups, sulphonic acid groups, phosphoric acid.
[0231] The term “cycloalkyl”, as used herein, refers to a monovalent or divalent group of 3 to 8 carbon atoms, derived from a saturated cyclic hydrocarbon. Cycloalkyl groups can be monocyclic or polycyclic. Cycloalkyl can be substituted by alkyl groups or halogen atoms.
[0232] The term “cycloalkenyl”, as used herein, refers to a monovalent or divalent group of 3 to 8 carbon atoms, derived from a saturated cycloalkyl having one double bond. Cycloalkenyl groups can be monocyclic or polycyclic. Cycloalkenyl groups can be substituted by alkyl groups or halogen atoms.
[0233] The term “halogen”, as used herein, refers to an atom of chlorine, bromine, fluorine, iodine.
[0234] The term “alkenyl”, as used herein, refers to a monovalent or divalent hydrocarbon radical having 2 to 6 carbon atoms, derived from a saturated alkyl, having at least one double bond. C 2-6 alkenyl can be in the E or Z configuration. Alkenyl groups can be substituted by alkyl groups.
[0235] The term “alkynyl”, as used herein, refers to a monovalent or divalent hydrocarbon radical having 2 to 6 carbon atoms, derived from a saturated alkyl, having at least one triple bond.
[0236] The term “heterocycle” as used herein, refers to a 3 to 10 membered ring, which can be aromatic or non-aromatic, saturated or non-saturated, containing at least one heteroatom selected form O or N or S or combinations of at least two thereof, interrupting the carbocyclic ring structure. The heterocyclic ring can be interrupted by a C═O; the S heteroatom can be oxidized. Heterocycles can be monocyclic or polycyclic. Heterocyclic ring moieties can be substituted by hydroxyl, alkyl groups or halogen atoms.
[0237] The term “aryl” as used herein, refers to an organic moiety derived from an aromatic hydrocarbon consisting of a ring containing 6 to 10 carbon atoms by removal of one hydrogen. Aryl can be monocyclic or polycyclic. Aryl can be substituted by halogen atoms, —OC 1-6 alkyl, C 1-6 alkyl, CN, C(O)(C 1-6 alkyl), N(C 1-6 alkyl) (C 1-6 alkyl) or NH 2 or NH(C 1-6 alkyl) or hydroxyl groups. Usually aryl is phenyl. Preferred substitution site on aryl are meta and para positions.
[0238] The term “hydroxyl” as used herein, represents a group of formula “—OH”.
[0239] The term “carbonyl” as used herein, represents a group of formula “—C(O)”.
[0240] The term “carboxyl” as used herein, represents a group of formula “—C(O)O—”.
[0241] The term “sulfonyl” as used herein, represents a group of formula “—SO 2 ”.
[0242] The term “sulfate” as used herein, represents a group of formula “—O—S(O) 2 —O—”.
[0243] The term “carboxylic acid” as used herein, represents a group of formula “—C(O)ON”.
[0244] The term “sulfoxide” as used herein, represents a group of formula “—S═O”.
[0245] The term “phosphonic acid” as used herein, represents a group of formula “—P(O)(OH) 2 ”.
[0246] The term “phosphoric acid” as used herein, represents a group of formula “—(O)P(O)(OH) 2 ”.
[0247] The term “sulphonic acid” as used herein, represents a group of formula “—S(O) 2 OH”.
[0248] The formula “H”, as used herein, represents a hydrogen atom.
[0249] The formula “O”, as used herein, represents an oxygen atom.
[0250] The formula “N”, as used herein, represents a nitrogen atom.
[0251] The formula “S”, as used herein, represents a sulfur atom.
[0252] Some compounds of the invention are:
3-({4-[({[(1E)-2-(3,5-difluorophenyl)-3-(3,4-dimethylphenyl)-1-methylpropylidene]amino}oxy)methyl]benzyl}amino)propanoic acid; [3-({4-[({[(1E)-2-(3,5-difluorophenyl)-3-(3,4-dimethylphenyl)-1-methylpropylidene]amino}oxy)methyl]benzyl}amino)propyl]phosphonic acid; [3-({4-[({[(1E)-2-(3-chlorophenyl)-3-(3,4-dimethylphenyl)-1-methylpropylidene]amino}oxy)methyl]benzyl}amino)propyl]phosphonic acid; 3-[(4-{(1E)-N-[3-(3,4-dimethylphenyl)-2-(3-methylphenyl)propoxy]ethanimidoyl}benzyl)amino]propanoic acid; 3-[(4-{(1E)-N-[2-(3-chlorophenyl)-3-(3,4-dimethylphenyl)propoxy]ethanimidoyl}benzyl)amino]propanoic acid; {3-[(4-{(1E)-N-[2-(3-chlorophenyl)-3-(3,4-dimethylphenyl)propoxy]ethanimidoyl}benzyl)amino]propyl}phosphonic acid; {3-[(4-{(1E)-N-[3-(3,4-dimethylphenyl)-2-(3-methylphenyl)propoxy]ethanimidoyl}benzyl)amino]propyl}phosphonic acid; [3-({4-[(1E)-N-{2-[(3,4-dimethylphenyl)sulfonyl]-2-(3-fluorophenyl)ethoxy}ethanimidoyl]benzyl}amino)propyl]phosphonic acid; 3-({4-[(1E)-N-{2-[(3,4-dimethylphenyl)thio]-2-(3-fluorophenyl)ethoxy}ethanimidoyl]benzyl}amino)propanoic acid; {3-[(4-{[({(1E)-2-(3-chlorophenyl)-2-[(3,4-dimethylphenyl)thio]-1-methylethylidene}amino)oxy]methyl}benzyl)amino]propyl}phosphonic acid; 3-[(4-{[({(1E)-2-(3-chlorophenyl)-2-[(3,4-dimethylphenyl)thio]-1-methylethylidene}amino)oxy]methyl}benzyl)amino]propanoic acid; 3-({4-[({[(1E)-2-(3-chlorophenyl)-2-(3,4-dimethylphenoxy)-1-methylethylidene]amino}oxy)methyl]benzyl}amino)propanoic acid; [3-({4-[({[(1E)-2-(3-chlorophenyl)-2-(3,4-dimethylphenoxy)-1-methylethylidene]amino}oxy)methyl]benzyl}amino)propyl]phosphonic acid; 3-[(4-{(1E)-N-[2-(3-chlorophenyl)-2-(3,4-dimethylphenoxy)ethoxy]ethanimidoyl}benzyl)amino]propanoic acid; {3-[(4-{(1E)-N-[2-(3-chlorophenyl)-2-(3,4-dimethylphenoxy)ethoxy]ethanimidoyl}benzyl)amino]propyl}phosphonic acid.
[0268] Some compounds of Formula I and some of their intermediates have at least one stereogenic center in their structure. This stereogenic center may be present in an R or S configuration, said R and S notation is used in correspondence with the rules described in Pure Appli. Chem. (1976), 45, 11-13.
[0269] The term “pharmaceutically acceptable salts” refers to salts or complexes that retain the desired biological activity of the above identified compounds and exhibit minimal or no undesired toxicological effects. The “pharmaceutically acceptable salts” according to the invention include therapeutically active, non-toxic base or acid salt forms, which the compounds of Formula I are able to form.
[0270] The acid addition salt form of a compound of Formula I that occurs in its free form as a base can be obtained by treating the free base with an appropriate acid such as an inorganic acid, for example, a hydrohalic acid, such as hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, nitric acid and the like; or an organic acid such as for example, acetic, hydroxyacetic, propanoic, lactic, pyruvic, malonic, fumaric acid, maleic acid, oxalic acid, tartaric acid, succinic acid, malic acid, ascorbic acid, benzoic acid, tannic acid, pamoic acid, citric, methylsulfonic, ethanesulfonic, benzenesulfonic, formic and the like (Handbook of Pharmaceutical Salts, P. Heinrich Stahal & Camille G. Wermuth (Eds), Verlag Helvetica Chemica Acta-Zürich, 2002, 329-345).
[0271] Compounds of Formula I and their salts can be in the form of a solvate, which is included within the scope of the present invention. Such solvates include for example hydrates, alcoholates and the like.
[0272] With respect to the present invention reference to a compound or compounds, is intended to encompass that compound in each of its possible isomeric forms and mixtures thereof unless the particular isomeric form is referred to specifically.
[0273] Compounds according to the present invention may exist in different polymorphic forms. Although not explicitly indicated in the above formula, such forms are intended to be included within the scope of the present invention.
[0274] The compounds of the invention are indicated for use in treating or preventing conditions in which there is likely to be a component involving the sphingosine-1-phosphate receptors.
[0275] In another embodiment, there are provided pharmaceutical compositions including at least one compound of the invention in a pharmaceutically acceptable carrier.
[0276] In a further embodiment of the invention, there are provided methods for treating disorders associated with modulation of sphingosine-1-phosphate receptors. Such methods can be performed, for example, by administering to a subject in need thereof a pharmaceutical composition containing a therapeutically effective amount of at least one compound of the invention.
[0277] These compounds are useful for the treatment of mammals, including humans, with a range of conditions and diseases that are alleviated by S1P modulation.
[0278] Therapeutic utilities of S1P modulators are Ocular Diseases: wet and dry age-related macular degeneration, diabetic retinopathy, retinopathy of prematurity, retinal edema, geographic atrophy, glaucomatous optic neuropathy, chorioretinopathy, hypertensive retinopathy, ocular ischemic syndrome, prevention of inflammation-induced fibrosis in the back of the eye, various ocular inflammatory diseases including uveitis, scleritis, keratitis, and retinal vasculitis;
[0279] Systemic vascular barrier related diseases: various inflammatory diseases, including acute lung injury, its prevention, sepsis, tumor metastasis, atherosclerosis, pulmonary edemas, and ventilation-induced lung injury;
[0280] Autoimmune diseases and immunosuppression: rheumatoid arthritis, Crohn's disease, Graves' disease, inflammatory bowel disease, multiple sclerosis, Myasthenia gravis, Psoriasis, ulcerative colitis, antoimmune uveitis, renal ischemia/perfusion injury, contact hypersensitivity, atopic dermatitis, and organ transplantation;
[0281] Allergies and other inflammatory diseases: urticaria, bronchial asthma, and other airway inflammations including pulmonary emphysema and chronic obstructive pulmonary diseases;
[0282] Cardiac functions: bradycardia, congestional heart failure, cardiac arrhythmia, prevention and treatment of atherosclerosis, and ischemia/reperfusion injury;
[0283] Wound Healing: scar-free healing of wounds from cosmetic skin surgery, ocular surgery, GI surgery, general surgery, oral injuries, various mechanical, heat and burn injuries, prevention and treatment of photoaging and skin ageing, and prevention of radiation-induced injuries;
[0284] Bone formation: treatment of osteoporosis and various bone fractures including hip and ankles;
[0285] Anti-nociceptive activity: visceral pain, pain associated with diabetic neuropathy, rheumatoid arthritis, chronic knee and joint pain, tendonitis, osteoarthritis, neuropathic pains;
[0286] Anti-fibrosis: ocular, cardiac, hepatic and pulmonary fibrosis, proliferative vitreoretinopathy, cicatricial pemphigoid, surgically induced fibrosis in cornea, conjunctiva and tenon;
[0287] Pains and anti-inflammation: acute pain, flare-up of chronic pain, musculo-skeletal pains, visceral pain, pain associated with diabetic neuropathy, rheumatoid arthritis, chronic knee and joint pain, tendonitis, osteoarthritis, bursitis, neuropathic pains;
[0288] CNS neuronal injuries: Alzheimer's disease, age-related neuronal injuries;
[0289] Organ transplants: renal, corneal, cardiac and adipose tissue transplants.
[0290] In still another embodiment of the invention, there are provided methods for treating disorders associated with modulation of sphingosine-1-phosphate receptors. Such methods can be performed, for example, by administering to a subject in need thereof a therapeutically effective amount of at least one compound of the invention, or any combination thereof, or pharmaceutically acceptable salts, hydrates, solvates, crystal forms and individual isomers, enantiomers, and diastereomers thereof.
[0291] The present invention concerns the use of a compound of Formula I or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for the treatment of Ocular Diseases: wet and dry age-related macular degeneration, diabetic retinopathy, retinopathy of prematurity, retinal edema, geographic atrophy, glaucomatous optic neuropathy, chorioretinopathy, hypertensive retinopathy, ocular ischemic syndrome, prevention of inflammation-induced fibrosis in the back of the eye, various ocular inflammatory diseases including uveitis, scleritis, keratitis, and retinal vasculitis;
[0292] Systemic vascular barrier related diseases: various inflammatory diseases, including acute lung injury, its prevention, sepsis, tumor metastasis, atherosclerosis, pulmonary edemas, and ventilation-induced lung injury;
[0293] Autoimmune diseases and immunosuppression: rheumatoid arthritis, Crohn's disease, Graves' disease, inflammatory bowel disease, multiple sclerosis, Myasthenia gravis, Psoriasis, ulcerative colitis, antoimmune uveitis, renal ischemia/perfusion injury, contact hypersensitivity, atopic dermatitis, and organ transplantation;
[0294] Allergies and other inflammatory diseases: urticaria, bronchial asthma, and other airway inflammations including pulmonary emphysema and chronic obstructive pulmonary diseases;
[0295] Cardiac functions: bradycardia, congestional heart failure, cardiac arrhythmia, prevention and treatment of atherosclerosis, and ischemia/reperfusion injury;
[0296] Wound Healing: scar-free healing of wounds from cosmetic skin surgery, ocular surgery, GI surgery, general surgery, oral injuries, various mechanical, heat and burn injuries, prevention and treatment of photoaging and skin ageing, and prevention of radiation-induced injuries;
[0297] Bone formation: treatment of osteoporosis and various bone fractures including hip and ankles;
[0298] Anti-nociceptive activity: visceral pain, pain associated with diabetic neuropathy, rheumatoid arthritis, chronic knee and joint pain, tendonitis, osteoarthritis, neuropathic pains;
[0299] Anti-fibrosis: ocular, cardiac, hepatic and pulmonary fibrosis, proliferative vitreoretinopathy, cicatricial pemphigoid, surgically induced fibrosis in cornea, conjunctiva and tenon;
[0300] Pains and anti-inflammation: acute pain, flare-up of chronic pain, musculo-skeletal pains, visceral pain, pain associated with diabetic neuropathy, rheumatoid arthritis, chronic knee and joint pain, tendonitis, osteoarthritis, bursitis, neuropathic pains;
[0301] CNS neuronal injuries: Alzheimer's disease, age-related neuronal injuries;
[0302] Organ transplants: renal, corneal, cardiac and adipose tissue transplants.
[0303] The actual amount of the compound to be administered in any given case will be determined by a physician taking into account the relevant circumstances, such as the severity of the condition, the age and weight of the patient, the patient's general physical condition, the cause of the condition, and the route of administration.
[0304] The patient will be administered the compound orally in any acceptable form, such as a tablet, liquid, capsule, powder and the like, or other routes may be desirable or necessary, particularly if the patient suffers from nausea. Such other routes may include, without exception, transdermal, parenteral, subcutaneous, intranasal, via an implant stent, intrathecal, intravitreal, topical to the eye, back to the eye, intramuscular, intravenous, and intrarectal modes of delivery. Additionally, the formulations may be designed to delay release of the active compound over a given period of time, or to carefully control the amount of drug released at a given time during the course of therapy.
[0305] In another embodiment of the invention, there are provided pharmaceutical compositions including at least one compound of the invention in a pharmaceutically acceptable carrier thereof. The phrase “pharmaceutically acceptable” means the carrier, diluent or excipient must be compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.
[0306] Pharmaceutical compositions of the present invention can be used in the form of a solid, a solution, an emulsion, a dispersion, a patch, a micelle, a liposome, and the like, wherein the resulting composition contains one or more compounds of the present invention, as an active ingredient, in admixture with an organic or inorganic carrier or excipient suitable for enteral or parenteral applications. Invention compounds may be combined, for example, with the usual non-toxic, pharmaceutically acceptable carriers for tablets, pellets, capsules, suppositories, solutions, emulsions, suspensions, and any other form suitable for use. The carriers which can be used include glucose, lactose, gum acacia, gelatin, mannitol, starch paste, magnesium trisilicate, talc, corn starch, keratin, colloidal silica, potato starch, urea, medium chain length triglycerides, dextrans, and other carriers suitable for use in manufacturing preparations, in solid, semisolid, or liquid form. In addition auxiliary, stabilizing, thickening and coloring agents and perfumes may be used. Invention compounds are included in the pharmaceutical composition in an amount sufficient to produce the desired effect upon the process or disease condition.
[0307] Pharmaceutical compositions containing invention compounds may be in a form suitable for oral use, for example, as tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsions, hard or soft capsules, or syrups or elixirs. Compositions intended for oral use may be prepared according to any method known in the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of a sweetening agent such as sucrose, lactose, or saccharin, flavoring agents such as peppermint, oil of wintergreen or cherry, coloring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparations. Tablets containing invention compounds in admixture with non-toxic pharmaceutically acceptable excipients may also be manufactured by known methods. The excipients used may be, for example, (1) inert diluents such as calcium carbonate, lactose, calcium phosphate or sodium phosphate; (2) granulating and disintegrating agents such as corn starch, potato starch or alginic acid; (3) binding agents such as gum tragacanth, corn starch, gelatin or acacia, and (4) lubricating agents such as magnesium stearate, stearic acid or talc. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate may be employed.
[0308] In some cases, formulations for oral use may be in the form of hard gelatin capsules wherein the invention compounds are mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin. They may also be in the form of soft gelatin capsules wherein the invention compounds are mixed with water or an oil medium, for example, peanut oil, liquid paraffin or olive oil.
[0309] The pharmaceutical compositions may be in the form of a sterile injectable suspension. This suspension may be formulated according to known methods using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglycerides, fatty acids (including oleic acid), naturally occurring vegetable oils like sesame oil, coconut oil, peanut oil, cottonseed oil, etc., or synthetic fatty vehicles like ethyl oleate or the like. Buffers, preservatives, antioxidants, and the like can be incorporated as required.
[0310] Invention compounds may also be administered in the form of suppositories for rectal administration of the drug. These compositions may be prepared by mixing the invention compounds with a suitable non-irritating excipient, such as cocoa butter, synthetic glyceride esters of polyethylene glycols, which are solid at ordinary temperatures, but liquefy and/or dissolve in the rectal cavity to release the drug.
[0311] Since individual subjects may present a wide variation in severity of symptoms and each drug has its unique therapeutic characteristics, the precise mode of administration and dosage employed for each subject is left to the discretion of the practitioner.
[0312] The compounds and pharmaceutical compositions described herein are useful as medicaments in mammals, including humans, for treatment of diseases and/or alleviations of conditions which are responsive to treatment by agonists or functional antagonists of sphingosine-1-phosphate receptors. Thus, in further embodiments of the invention, there are provided methods for treating a disorder associated with modulation of sphingosine-1-phosphate receptors. Such methods can be performed, for example, by administering to a subject in need thereof a pharmaceutical composition containing a therapeutically effective amount of at least one invention compound. As used herein, the term “therapeutically effective amount” means the amount of the pharmaceutical composition that will elicit the biological or medical response of a subject in need thereof that is being sought by the researcher, veterinarian, medical doctor or other clinician. In some embodiments, the subject in need thereof is a mammal. In some embodiments, the mammal is human.
[0313] The present invention concerns also processes for preparing the compounds of Formula I. The compounds of formula I according to the invention can be prepared analogously to conventional methods as understood by the person skilled in the art of synthetic organic chemistry. The synthetic schemes set forth below, illustrate how compounds according to the invention can be made.
[0314] The following abbreviations are used in the general schemes and in the specific examples:
[0000] THF tetrahydrofuran
MPLC medium pressure liquid chromatography
NMO 4-Methylmorpholine N-oxide
[0315] CH 3 CN acetonitrile
CH 2 Cl 2 dichloromethane
TPAP Tetrapropylammonium perruthenate
MeOH methanol
NaCNBH 3 sodium cyanoborohydride
CD 3 OD deuterated methanol
DMSO-d6 deuterated dimethyl sulfoxide
NaOMe sodium methoxyde
EtOH ethanol
NaBH 4 sodium borohydride
MgSO 4 magnesium sulfate
NH 4 Cl ammonium chloride
HCl hydrochloric acid
DIBAL-H Diisobutylaluminium hydride
Et 2 O ether
MeOH methanol
K 2 CO 3 potassium carbonate
DMF N,N-dimethylformamide
[0316] Et 3 N triethylamine
CuI cooper iodide
PdCl 2 (PPh 3 ) 2 Bis(triphenylphosphine)palladium(II) chloride
NaH sodium hydride
EtOAc ethylacetate
AcOH acetic acid
TFA trifluoroacetic acid
NH 3 ammonia
CDCl 3 deuterated chloroform
n-Bu 4 NOH Tetrabutylammonium hydroxide
NH 2 NH 2 hydrazine
LAH or LiAlH 4 Lithium aluminium hydride
DEAD diethyl azodicarboxylate
Ph 3 P triphenylphosphine
Synthetic Scheme for Obtained Compound of Formula I Wherein D is
[0317]
[0000]
General Procedure A for Obtaining Intermediate 1
[0318] The starting material, a carboxylic acid (7.82 mmol) prepared according to, Marvin J. et al, Journal of Medicinal Chemistry, 44, 4230-4251, 2001 was dissolved in anhydrous ether (100 mL) at −10° C. A solution of LiAlH 4 (3.9 mL, 2.0M in hexane, 7.82 mmol) was added slowly and the reaction mixture was stirred at room temperature for 4 hours. The reaction was then quenched with aqueous NH 4 Cl and extracted with ether. The combined organic layers were washed with H 2 O and brine, then dried over Na 2 SO 4 . The solvent was removed under reduced pressure. The corresponding alcohol was obtained and isolated by MPLC using 10 to 20% ethyl acetate in hexane.
[0319] Diethyl azodicarboxylate (2.58 ml, 40% in toluene, 5.94 mmol) was added dropwise at 0° C. to this alcohol derivative (1.16 g, 4.57 mmol) with triphenylphosphine (1.44 g, 5.48 mmol), and N-hydroxyphthalimide (896 mg, 5.48 mmol) in THF (50 mL). The mixture was stirred at room temperature for 16 h and evaporated to dryness. The residue was purified by MPLC using 20-40% ethyl acetate in hexane to afford the corresponding N-alkoxyphthalimide.
[0320] A mixture of the above N-alkoxyphthalimide (2.0 g, 5 mmol) and hydrazine monohydrate (0.25 mL, 5 mmol) in MeOH (30 mL) was heated under reflux for 4 h. After cooling, the resulting suspension was filtered, and the filtrate was evaporated. The residue was triturated with Et 2 O and filtered, and the filtrate was evaporated to dryness. The residue was purified by MPLC using 10-20% ethyl acetate in hexane to give the corresponding hydroxylamine of Intermediate 1 type.
General Procedure B for Obtaining Intermediate 2
[0321] To the mixture of Intermediate 1 (1.15 g, 4.27 mmol) and 1-(4-hydroxylmethyl) phenyl)ethanone (641 mg, 4.27 mmol) prepared according to Zhengqiang et al, Journal of Medicinal Chemistry, 50(15), 3416-3419; 2007, in methanol (20 mL) were added 3 drops of HOAc. The reaction solution was stirred at room temperature for 16 hours and then evaporated to dryness. The corresponding alcohol compound was obtained and purified by MPLC using 0-40% ethyl acetate in hexane.
[0322] The above alcohol (4.24 mmol) was mixed with NMO (1.24 g, 10.6 mmol), molecular sieve (600 mg) in AcCN (5 mL) and DCM (25 mL). A catalytic amount of TPAP (40 mg) was added. The resulting reaction mixture was stirred at RT for 1 hour and evaporated to dryness. The aldehyde Intermediate 2 type, was purified by MPLC using 0-10% ethyl acetate in hexane.
[0000] General Procedure C for Obtaining a Compound of Formula I Wherein from Intermediate 2
[0000]
[0323] An intermediate 2 (250 mg, 0.62 mmol), β-alanine (52 mg, 0.59 mmol) and TEA (0.1 ml, 0.7 mmol) were stirred in MeOH (10 ml). Upon stirring at 60° C. for 90 min, the reaction solution was cooled to RT. NaBH 4 (50 mg, 1.35 mmol) was added and stirred at RT for 2 hour. The reaction was quenched with 0.5 mL of water and concentrated to minimal amount. The compound of Formula I was isolated by reverse phase MPLC using 10 to 90% H 2 O in AcCN.
[0000] General Procedure D for Obtaining a Compound of Formula I Wherein from Intermediate 2
[0000]
[0000] Intermediate 2 (130 mg, 0.88 mmol), 3-aminopropylphosphonic acid (122 mg, 0.88 mmol) and tetra-n-butylammonium hydroxide (0.88 ml, 1.0M/MeOH, 0.88 mmol) were stirred in MeOH (10 ml). Upon stirring at 50° C. for 30 min, NaBH 3 CN (55 mg, 0.88 mmol) was added and stirred at 50° C. for 3 hour. The reaction was quenched with 0.5 mL of water and concentrated to a minimal amount. The compound of Formula I was isolated by MPLC using 10 to 90% MeOH in EtOAc.
[0000]
Synthetic Scheme for Obtained Compound of Formula I Wherein D is
[0324]
[0325] The compounds of Formula I wherein D is
[0000]
[0000] are prepared according to procedures B and C as described above. The carboxylic acid staring material is replaced with a methyl ketone prepared according to Marvin J. et al, Journal of Medicinal Chemistry, 44, 4230-4251, 2001. The methyl ketone reacted with {4-[(aminooxy)methyl]phenyl}methanol, prepared according to Fensholdt, Jef et al, WO 200505417 according to the B procedure to afford the aldehyde Intermediate 3. Intermediate 3 is used in procedures C or D, as described above, to afford the compounds of Formula I.
[0326] Those skilled in the art will be able to routinely modify and/or adapt the following scheme to synthesize any compounds of the invention covered by Formula I.
DETAILED DESCRIPTION OF THE INVENTION
[0327] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention claimed. As used herein, the use of the singular includes the plural unless specifically stated otherwise.
[0328] It will be readily apparent to those skilled in the art that some of the compounds of the invention may contain one or more asymmetric centers, such that the compounds may exist in enantiomeric as well as in diastereomeric forms. Unless it is specifically noted otherwise, the scope of the present invention includes all enantiomers, diastereomers and racemic mixtures. Some of the compounds of the invention may form salts with pharmaceutically acceptable acids or bases, and such pharmaceutically acceptable salts of the compounds described herein are also within the scope of the invention.
[0329] The present invention includes all pharmaceutically acceptable isotopically enriched compounds. Any compound of the invention may contain one or more isotopic atoms enriched or different than the natural ratio such as deuterium 2 H (or D) in place of protium 1 H (or H) or use of 13 C enriched material in place of 12 C and the like. Similar substitutions can be employed for N, O and S. The use of isotopes may assist in analytical as well as therapeutic aspects of the invention. For example, use of deuterium may increase the in vivo half-life by altering the metabolism (rate) of the compounds of the invention. These compounds can be prepared in accord with the preparations described by use of isotopically enriched reagents.
[0330] The following examples are for illustrative purposes only and are not intended, nor should they be construed as limiting the invention in any manner. Those skilled in the art will appreciate that variations and modifications of the following examples can be made without exceeding the spirit or scope of the invention.
[0331] As will be evident to those skilled in the art, individual isomeric forms can be obtained by separation of mixtures thereof in conventional manner. For example, in the case of diasteroisomeric isomers, chromatographic separation may be employed.
[0332] Compound names were generated with ACD version 8; intermediates and reagent names used in the examples were generated with software such as Chem Bio Draw Ultra version 12.0 or Auto Nom 2000 from MDL ISIS Draw 2.5 SP1.
[0333] In general, characterization of the compounds is performed according to the following methods: Proton nuclear magnetic resonance ( 1 H NMR) and carbon nuclear magnetic resonance ( 13 C NMR) spectra were recorded on a Varian 300 or 600 MHz spectrometer in deuterated solvent. Chemical shifts were reported as δ (delta) values in parts per million (ppm) relative to tetramethylsilane (TMS) as an internal standard (0.00 ppm) and multiplicities were reported as s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet; br, broad. Data were reported in the following format: chemical shift (multiplicity, coupling constant(s) J in hertz (Hz), integrated intensity).
[0334] All the reagents, solvents, catalysts for which the synthesis is not described are purchased from chemical vendors such as Sigma Aldrich, Fluka, Bio-Blocks, Combi-blocks, TCI, VWR, Lancaster, Oakwood, Trans World Chemical, Alfa, Fisher, Maybridge, Frontier, Matrix, Ukrorgsynth, Toronto, Ryan Scientific, SiliCycle, Anaspec, Syn Chem, Chem-Impex, MIC-scientific, Ltd; however some known intermediates, were prepared according to published procedures.
[0335] Usually the compounds of the invention were purified by column chromatography (Auto-column) on an Teledyne-ISCO CombiFlash with a silica column, unless noted otherwise.
[0000] Compounds 1 to 15 were prepared according to the general procedures A, B, C and D. The starting materials, intermediates and the results are tabulated below in Table 1 for each case. Compounds 1, 2, 3 and 4 were generated from Intermediates type 1 and 2. Compounds 5, 6 and 7 were generated from Intermediates type 3.
[0000]
TABLE 1
Compound
Starting
material
Intermediate
IUPAC name
1 H NMR (Solvent; δ ppm)
Compound 1
1 H NMR (300 MHz, CD 3 OD) δ ppm 2.09 (s, 3H) 2.14 (s, 3H) 2.16 (s, 3H) 2.28 (s, 3H) 2.44 (t, J = 6.74 Hz, 2H) 2.79-2.93 (m, 3H) 2.98-3.08 (m, 1H) 3.27 (s, 1H) 3.86 (s, 2H) 4.30 (dd, J = 6.74, 2.05 Hz, 2H) 6.76 (d, J = 7.62 Hz, 1H) 6.82 (s, 1H) 6.91 (d, J = 7.62 Hz, 1H) 6.94-7.02 (m, 3H) 7.08-7.16 (m, 1H) 7.38 (d, J = 8.20 Hz, 2H) 7.60 (d, J = 8.20 Hz, 2H).
Compound 2
1 H NMR (300 MHz, CD 3 OD) δ ppm 1.58-1.76 (m, 2H) 1.87-2.06 (m, 2H) 2.11 (s, 3H) 2.14 (s, 3H) 2.16 (s, 3H) 2.28 (s, 3H) 2.79-2.90 (m, 1H) 2.96-3.14 (m, 3H) 3.23-3.28 (m, 1H) 4.13 (s, 2H) 4.27-4.35 (m, 2H) 6.76 (d, J = 7.60 Hz, 1H) 6.84 (s, 1H) 6.90 (d, J = 7.60 Hz, 1H) 6.90-6.99 (m, 3H) 7.09-7.17 (m, 1H) 7.49 (d, J = 8.50 Hz, 2H) 7.69 (d, J = 8.50 Hz, 2H).
Starting
2-(3-methylphenyl)-3-(3,4-dimethylphenyl)propanoic
material
Intermediate
4-[3-(aminooxy)-2-(3-methylphenyl)propyl]-1,2-dimethylbenzene
1 H NMR (300 MHz, CD 3 OD)
1
δ ppm 2.13 (s, 3H) 2.14 (s,
3H) 2.25 (s, 3H) 2.64-2.82 (m,
1H) 2.90-2.99 (m, 1H) 3.12
(m, 1H) 3.79 (d, J = 6.74 Hz,
2H) 6.74 (d, J = 7.62 Hz, 1H)
6.80 (s, 1H) 6.88-6.95 (m, 4H)
7.06-7.13 (m, 1H).
Intermediate
4-{(1E)-N-[2-(3-methylphenyl)-3-(3,4-
1 H NMR (300 MHz, CD 3 OD)
2
dimethylphenyl)propoxy]ethanimidoyl}benzaldehyde
δ ppm 2.12-2.19 (m, 9H) 2.29
(s, 3H) 2.81-2.92 (m, 1H)
2.98-3.08 (m, 1H) 3.32-3.34
(m, 1H) 4.36 (dd, J = 6.89,
1.61 Hz, 2H) 6.75-6.86 (m,
2H) 6.89-7.05 (m, 4H)
7.10-7.17 (m, 1H) 7.90 (d,
J = 8.20 Hz, 2H) 7.81 (d,
J = 8.20 Hz, 2H) 10.00 (s,
1H).
Compound 3
1 H NMR (300 MHz, CD 3 OD) δ ppm 2.09 (s, 3H) 2.15 (s, 3H) 2.16 (br. s., 3H) 2.44 (t, J = 6.74 Hz, 2H) 2.78-2.92 (m, 3H) 2.98-3.07 (m, 1H) 3.33-3.38 (m, 1H) 3.84 (s, 2H) 4.32 (m, 2H) 6.75-6.79 (d, J = 7.62 Hz, 1H) 6.84 (s, 1H) 6.91 (d, J = 6.72, 1H) 7.09-7.23 (m, 4H) 7.37 (d, J = 8.20 Hz, 2H) 7.59 (d, J = 8.20 Hz, 2H)
Compound 4
1 H NMR (300 MHz, CD 3 OD) δ ppm 1.60-1.72 (m, 2H) 1.91-2.04 (m, 2H) 2.09 (s, 3H) 2.15 (s, 3H) 2.16 (s, 3H) 2.79-2.88 (m, 1H) 2.95-3.08 (m, 3H) 3.33-3.38 (m, 1H) 4.11 (s, 2H) 4.25-4.35 (m, 2H) 6.78 (d, J = 7.5 Hz, 1H) 6.83 (m, 1H) 6.93 (d, J = 7.50 Hz, 1H) 7.09-7.25 (m, 4H) 7.50 (d, J = 8.20 Hz, 2H) 7.67 (d, J = 8.20 Hz, 2H)
Starting
2-(3-chlorophenyl)-3-(3,4-dimethylphenyl)propanoic acid
material
Intermediate
4-[3-(aminooxy)-2-(3-chlorophenyl)propyl]-1,2-dimethylbenzene
1 H NMR (300 MHz, CD 3 OD)
1
δ ppm 2.16 (s, 6H) 2.61-2.84
(m, 1H) 2.89-3.03 (m, 1H)
3.19 (m, 1H) 3.81 (d, J = 6.45
Hz, 2H) 6.75 (d, J = 7.91 Hz,
1H) 6.81 (s, 1H) 6.92 (d,
J = 7.91 Hz, 1H) 7.04-7.26
(m, 4H)
Intermediate
4-{(1E)-N-[2-(3-chlorophenyl)-3-(3,4-
1 H NMR (300 MHz, CD 3 OD)
2
dimethylphenyl)propoxy]ethanimidoyl}benzaldehyde
δ ppm 2.13 (s, 3H) 2.15 (br.
s., 3H) 2.16 (br. s., 3H)
2.80-2.90 (m, 1H) 2.97-3.07
(m, 1H) 3.33-3.42 (m, 1H)
4.37 (m, 2H) 6.79 (d, J = 7.62
Hz, 1H) 6.84 (s, 1H) 6.93 (d,
J =7.62 Hz, 1H) 6.84 (s, 1H)
6.93 (d, J = 7.62 Hz, 1H)
7.09-7.26 (m, 4H) 7.79 (d,
J = 8.5 Hz, 2H) 7.87 (d,
J = 8.5 Hz, 2H) 9.98 (s, 1H)
Compound 5
1 H NMR (300 MHz, CD 3 OD) δ ppm 1.66-1.71 (m, 2H) 1.68 (s, 3H) 1.88-2.06 (m, 2H)2.14 (s, 3H) 2.16 (s, 3H) 2.81-2.92 (m, 1H) 3.05 (t, J = 6.40 Hz, 2H) 3.13-3.20 (m, 1H) 3.71 (t, J = 7.91 Hz, 1H) 4.11 (s, 2H) 5.11 (s, 2H) 6.68-6.75 (d, J = 7.62 Hz, 1H) 6.78 (s, 1H) 6.88 (t, J = 7.62 Hz, 1H) 7.01-7.28 (m, 4H) 7.38 (d, J = 8.20 Hz, 2H) 7.48 (t, J = 8.20 Hz, 2H).
Starting
3-(3-chlorophenyl)-4-(3,4-dimethylphenyl)butan-2-one
material
Intermediate
4-[({[(1E)-2-(3-chlorophenyl)-3-(3,4-dimethylphenyl)-1-
1 H NMR (300 MHz, CD 3 OD)
3
methylpropylidene]amino}oxy)methyl]benzaldehyde
δ ppm 1.75 (s, 3H) 2.13 (s,
3H) 2.18 (s, 3H) 2.83-2.93 (m,
1H) 3.14-3.23 (m, 1H) 3.76 (t,
J = 7.90 Hz, 1H) 5.19 (s, 2H)
6.703 (d, J = 7.62 Hz, 1H)
6.81 (s, 1H) 6.88 (d, J = 7.62
Hz, 1H) 7.05-7.11 (m, 1H)
7.14 (s, 1H) 7.19-7.23 (m, 2H)
7.44 (d, J = 8.50 Hz, 2H) 7.85
(d, J = 8.50 Hz, 2H) 9.99 (s,
1H).
Compound 6
1 H NMR (300 MHz, CD 3 OD) δ ppm 1.57-1.68 (m, 2H) 1.71 (s, 3H) 1.87-2.06 (m, 2H) 2.15 (s, 3H) 2.17 (s, 3H) 2.79-2.93 (m, 1H) 3.03 (t, J = 6.30 Hz, 2H) 3.12-3.19 (m, 1H) 3.75 (t, J = 7.91 Hz, 1H) 4.12 (s, 2H) 5.12 (s, 2H) 6.64-6.76 (m, 4H) 6.80-6.84 (m, 1H) 6.88-6.96 (d, J = 7.62 Hz, 1H) 7.40 (d, J = 8.30 Hz, 2H) 7.47 (d, J = 8.30 Hz, 2H).
Compound 7
1 H NMR (300 MHz, CD 3 OD) δ ppm 1.71 (s, 3H) 2.16 (s, 3H) 2.18 (s, 3H) 2.44 (t, J = 6.74 Hz, 2H) 2.83-2.95 (m, 3H) 3.18 (dd, J = 13.77, 7.62 Hz, 1H) 3.76 (t, J = 7.90 Hz, 1H) 3.87 (s, 2H) 5.10 (s, 2H) 6.67-6.80 (m, 4H) 6.82 (s, 1H) 6.92 (d, J = 7.62 Hz, 1H) 7.33 (m, 4H).
Starting
3-(3,5-difluorophenyl)-4-(3,4-dimethylphenyl)butan-2-one
material
Intermediate
4-[({[(1E)-2-(3,5-difluorophenyl)-3-(3,4-dimethylphenyl)-1-
1 H NMR (300 MHz, CD 3 OD)
3
methylpropylidene]amino}oxy)methyl]benzaldehyde
δ ppm 1.75 (s, 3H) 2.13 (s,
3H) 2.17 (s, 3H) 2.83-2.93 (m,
1H) 3.12-3.22 (m, 1H) 3.79 (t,
J = 7.9 Hz, 1H) 5.19 (s, 2H)
6.69-6.84 (m, 5H) 6.90 (d,
J = 7.62 Hz, 1H) 7.44 (d,
J = 8.20 Hz, 2H) 7.84 (d,
J = 8.20 Hz, 2H) 9.98 (s, 1H).
Compound 8
1 H NMR (600 MHz, CD 3 OD) δ ppm 1.57-1.70 (m, 2H) 1.90-1.99 (m, 2H) 2.14-2.20 (m, 9H) 2.98 (t, J = 6.31 Hz, 2H) 3.27-3.32 (m, 1H) 3.49 (dd, J = 14.06, 6.45 Hz, 1H) 4.04 (s, 2H) 5.30 (t, J = 6.31 Hz, 2H) 6.94-7.02 (m, 2H) 7.03-7.16 (m, 4H) 7.27-7.34 (m, 1H) 7.47 (d, J = 8.22 Hz, 2H) 7.61 (d, J = 8.22 Hz, 2H)
Compound 9
1 H NMR (300 MHz, CD 3 OD) δ ppm 2.18 (s, 6H) 2.20 (s, 3H) 2.40 (t, J = 6.74 Hz, 2H) 2.84 (t, J = 6.74 Hz, 2H) 3.30 (m, 1H) 3.51 (dd, J = 14.06, 6.45 Hz, 1H) 3.80 (s, 2H) 5.31 (t, J = 6.74 Hz, 1H) 6.92-7.21 (m, 6H) 7.32 (m, 1H) 7.34 (d, J = 8.50 Hz, 2H) 7.56 (d, J = 8.50 Hz, 2H)
Compound 10
1 H NMR (600 MHz, CD 3 OD) δ ppm 1.62-1.73 (m, 2H) 1.83-1.88 (m, 3H) 1.90-1.99 (m., 2H) 2.17-2.22 (m, 3H) 2.25-2.29 (m, 3H) 3.08 (t, J = 6.31 Hz, 2H) 4.15 (s, 2H) 4.90-5.08 (m, 3H) 6.98-7.07 (m, 2H) 7.10 (s, 1H) 7.21-7.40 (m, 6H) 7.43-7.49 (m, 2H)
Compound 11
1 H NMR (300 MHz, CD 3 OD) δ ppm 1.81-1.84 (m, 3H) 2.15 (s, 3H) 2.19 (s, 3H) 2.43 (t, J = 6.74 Hz, 2H) 2.87 (t, J = 6.74 Hz, 2H) 3.81 (s, 2H) 4.92-5.02 (m, 3H) 6.93-7.12 (m, 3H) 7.13-7.42 (m, 8H)
Compound 12
1 H NMR (300 MHz, DMSO-d 6 ) δ ppm 1.67 (s, 3H) 2.11 (d, J = 4.10 Hz, 6H) 2.20-2.36 (m, 2H) 2.59-2.83 (m, 2H) 3.77 (br. s., 2H) 5.08 (s, 2H) 5.88 (s, 1H) 6.62-6.78 (m, 1H) 6.84 (d, J = 2.64 Hz, 1H) 6.96 (d, J = 8.20 Hz, 1H) 7.22-7.35 (m, 5H) 7.36-7.43 (m, 3H).
Compound 13
1 H NMR (300 MHz, CDCl 3 ) δ ppm 1.56-1.77 (m, 5H) 1.94-2.09 (m, 2H) 2.14 (d, J = 4.98 Hz, 6H) 2.73 (br. s, 2H) 3.97 (br. s., 2H) 5.02 (s, 2H) 5.67 (s, 1H) 6.65 (dd, J = 8.20, 2.64 Hz, 1H) 6.71-6.81 (m, 1H) 6.93 (d, J = 8.20 Hz, 1H) 7.12-7.33 (m, 6H) 7.36-7.53 (m, 3H).
Compound 14
1 H NMR (300 MHz, DMSO-d 6 ) δ ppm 2.05 (s, 3H) 2.06-2.11 (m, 6H) 2.29 (t, J = 6.74 Hz, 2H) 2.71 (t, J = 6.74 Hz, 2H) 3.77 (br. s., 2H) 4.34 (dd, J = 4.40 Hz, 1H) 4.44 (dd, J = 7.00 Hz, 1H) 5.57-5.68 (m, 1H) 6.55-6.67 (m, 1H) 6.76 (d, J = 2.64 Hz, 1H) 6.91 (d, J = 8.20 Hz, 1H) 7.28-7.46 (m, 6H) 7.50 (br. s., 1H) 7.55-7.65 (m, 2H).
Compound 15
1 H NMR (300 MHz, DMSO-d 6 ) δ ppm 1.66-1.87 (m, 2H) 1.95-2.12 (m, 9H) 2.71 (br. s., 2H) 3.06-3.23 (m, 2H) 3.85 (br. s., 2H) 4.20-4.36 (m, 1H) 4.39-4.53 (m, 1H) 5.56-5.67 (m, 1H) 6.51-6.66 (m, 1H) 6.74 (d, J = 2.05 Hz, 1H) 6.88 (d, J = 8.20 Hz, 1H) 7.22-7.44 (m, 4H) 7.49 (d, J = 4.10 Hz, 3H) 7.52-7.66 (m, 2H).
Biological Data
[0336] Compounds were synthesized and tested for S1P1 activity using the GTP γ 35 S binding assay. These compounds may be assessed for their ability to activate or block activation of the human S1P1 receptor in cells stably expressing the S1P1 receptor.
[0337] GTP γ 35 S binding was measured in the medium containing (mM) HEPES 25, pH 7.4, MgCl 2 10, NaCl 100, dithitothreitol 0.5, digitonin 0.003%, 0.2 nM GTP γ 35 S, and 5 μg membrane protein in a volume of 150 μl. Test compounds were included in the concentration range from 0.08 to 5,000 nM unless indicated otherwise. Membranes were incubated with 100 μM 5′-adenylylimmidodiphosphate for 30 min, and subsequently with 10 μM GDP for 10 min on ice. Drug solutions and membrane were mixed, and then reactions were initiated by adding GTP γ 35 S and continued for 30 min at 25° C. Reaction mixtures were filtered over Whatman GF/B filters under vacuum, and washed three times with 3 mL of ice-cold buffer (HEPES 25, pH7.4, MgCl 2 10 and NaCl 100). Filters were dried and mixed with scintillant, and counted for 35 S activity using a β-counter. Agonist-induced GTP γ 35 S binding was obtained by subtracting that in the absence of agonist. Binding data were analyzed using a non-linear regression method. In case of antagonist assay, the reaction mixture contained 10 nM S1P in the presence of test antagonist at concentrations ranging from 0.08 to 5000 nM.
[0000] Table 2 shows activity potency: S1P1 receptor from GTP γ 35 S: nM, (EC 50 ).
Activity Potency:
[0338] S1P1 receptor from GTP γ 35 S: nM, (EC 50 ),
[0000]
TABLE 2
S1P1
IUPAC name
EC 50 (nM)
3-({4-[({[(1E)-2-(3,5-difluorophenyl)-3-(3,4-dimethylphenyl)-1-
6.8
methylpropylidene]amino}oxy)methyl]benzyl}amino)propanoic acid
[3-({4-[({[(1E)-2-(3,5-difluorophenyl)-3-(3,4-dimethylphenyl)-1-methylpropylidene]amino}oxy)methyl]benzyl}amino)propyl]phosphonic
0.88
acid
[3-({4-[({[(1E)-2-(3-chlorophenyl)-3-(3,4-dimethylphenyl)-1-methylpropylidene]amino}oxy)methyl]benzyl}amino)propyl]phosphonic
2.2
acid
3-[(4-{(1E)-N-[3-(3,4-dimethylphenyl)-2-(3-
43.2
methylphenyl)propoxy]ethanimidoyl}benzyl)amino]propanoic acid
3-[(4-{(1E)-N-[2-(3-chlorophenyl)-3-(3,4-
15.6
dimethylphenyl)propoxy]ethanimidoyl}benzyl)amino]propanoic acid
{3-[(4-{(1E)-N-[2-(3-chlorophenyl)-3-(3,4-dimethylphenyl)propoxy]ethanimidoyl}benzyl)amino]propyl}phosphonic
3.51
acid
{3-[(4-{(1E)-N-[3-(3,4-dimethylphenyl)-2-(3-methylphenyl)propoxy]ethanimidoyl}benzyl)amino]propyl}phosphonic
23.4
acid
{3-[(4-{[({(1E)-2-(3-chlorophenyl)-2-[(3,4-dimethylphenyl)thio]-1-methylethylidene}amino)oxy]methyl}benzyl)amino]propyl}phosphonic
8.34
acid
{3-[(4-{(1E)-N-[2-(3-chlorophenyl)-2-(3,4-dimethylphenoxy)ethoxy]ethanimidoyl}benzyl)amino]propyl}phosphonic
11.42
acid
3-[(4-{(1E)-N-[2-(3-chlorophenyl)-2-(3,4-
215.56
dimethylphenoxy)ethoxy]ethanimidoyl}benzyl)amino]propanoic acid
[3-({4-[(1E)-N-{2-[(3,4-dimethylphenyl)sulfonyl]-2-(3-fluorophenyl)ethoxy}ethanimidoyl]benzyl}amino)propyl]phosphonic
51.81
acid | The present invention relates to novel oxime derivatives, processes for preparing them, pharmaceutical compositions containing them and their use as pharmaceuticals as modulators of sphingosine-1-phosphate receptors. | 2 |
BACKGROUND OF THE INVENTION
This invention relates to an exhaust emission control apparatus for a Diesel engine, and more particularly to an apparatus of the kind above described which can regenerate a filter provided for collecting particulates contained in engine exhaust gases.
As means for minimizing emission of particulates contained in exhaust gases of a Diesel engine, an apparatus is known in which a filter is disposed in the exhaust pipe to collect the particulates, and a burner is provided for burning the collected particulates thereby reducing the pressure loss across the filter due to the presence of the collected particulates.
However, since the filter is usually made of a porous ceramic material capable of withstanding a high temperature of about 1,200° C. to 1,300° C., while, on the other hand, the combustion temperature of the particulates is about 500° C. to 600° C., the filter will be damaged by the heat generated from the burner when the heat of combustion exceeds 1,300° C. although the combustion of the particulates may be successfully attained.
In order to avoid damage to the filter due to the heat, it is necessary to control the fuel supply so that the combustion temperature of the particulates in the filter is maintained within the range of from 600° C. to 1,200° C., and the particulates only can be efficiently burnt. As means for controlling the fuel supply, a fuel control system including an air assist type burner as disclosed in Japanese patent application Laid-open No. 57-212317 (1982) has been proposed and has achieved a considerable success in practical use. However, proposed auto emission standard have set forth a target of a very high level in regard to the amount of particulates contained in exhaust gases of Diesel engines. Therefore, in order to achieve the target of the very high level set forth by the these standards the prior art fuel control system including the an air assist type burner, and using assist air at a predetermined pressure to control the pressure of fuel continuously supplied for combustion of particulates, has had limitations from the viewpoint of more accurate electronic control of the amount of fuel supply and also from the viewpoint of satisfactory atomization of fuel.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide an exhaust emission control apparatus for a Diesel engine, which can electronically control the fuel supply with higher accuracy and can realize complete combustion of fuel by satisfactory atomization of fuel.
According to the present invention which attains the above object, fuel required for causing combustion of particulates collected in a filter is discontinuously supplied, and the duty determining the duration of fuel supply is electronically controlled so as to control the amount of fuel with higher accuracy. Also, according to the present invention, the fuel is emitted from a fuel jet nozzle, and an air assist is discontinuously supplied from a location in the vicinity of the nozzle for satisfactorily atomizing the emitted fuel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view showing schematically the structure of an embodiment of the exhaust emission control apparatus according to the present invention.
FIG. 2 is a schematic sectional view of part of the fuel supply device incorporated in the apparatus of the present invention.
FIG. 3 is an enlarged view of the fuel jet part in FIG. 2.
FIG. 4 is a plan view of the swirler tip shown in FIG. 2.
FIG. 5 is a flow chart showing, by way of example, the steps of fuel supply control according to the present invention.
FIG. 6 is a block diagram of one form of the duty signal generating circuit incorporated in the apparatus of the present invention.
FIGS. 7 to 10 are graphs illustrating the effects of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a diagrammatic view showing schematically the structure of a preferred embodiment of the Diesel-engine exhaust emission control apparatus according to the present invention. Referring to FIG. 1, information of the operation parameters of an engine 9, such as the engine rotation speed and the amount of intake air, and information of the control parameters of a filter 10, including the outputs from a flame sensor 11, a temperature sensor 12 and a pressure sensor 13, are applied to a control unit 2. On the basis of the above information, the control unit 2 computes the amount of heat required for combustion of particulates collected in the filter 10 and applies to a fuel supply device 1 a duty signal for controlling the amount of fuel to be supplied from the fuel supply device 1. Fuel supplied under pressure from a fuel pump 3 is emitted from the fuel supply device 1 toward the filter 10 according to the duty cycle of the duty signal. The emitted fuel is atomized by an air assist whose pressure pulsates at a frequency determined by the rotation speed of an air pump 4 driven by a DC motor 34. The atomized fuel is then ignited by sparks generated from an ignition unit 6 to which a high voltage is applied from an igniter 5 for generating such sparks. Primary air from another air pump 7 is swirled by a swirler 8 to be sufficiently mixed with fuel thereby ensuring complete combustion of the fuel-air mixture. The pure high-temperature gas produced as a result of complete combustion of the fuel-air mixture is supplied to the particulate filter 10 for oxidizing particulates collected in the filter 10.
The structure of the fuel supply device 1 and components in the vicinity of will be described in more detail with reference to FIG. 2. Referring to FIG. 2, a coil 14 is incorporated in the fuel supply device 1, and a plunger 15 capable of making vertical or axial movement in response to the energization of the coil 14 extends through the coil 14. A ball valve member 16 is fixed to the front or upper end of the plunger 15 to normally engage the inner wall surface of a nozzle 17. The ball valve member 16 is disengaged from the inner wall surface of the nozzle 17 when the plunger 15 makes its downward movement in FIG. 2. A port is bored in the side wall of the body of the fuel supply device 1 where the plunger 15 is disposed, so that fuel from the fuel pump 3 can be supplied to the fuel supply device 1 through a fuel pipe 30. The supplied fuel is emitted from the nozzle 17 when the ball valve member 16 is urged to its open position due to the energization of the coil 14. The coil 14 is energized under control of the duty signal applied from the control unit 2.
An air assist jet port 25 is formed around the periphery of the upper portion of the nozzle 17. Assisting air from the air pump 4 passes through an air pipe 18 and an air assist passage 22 to be emitted from the air assist jet part 25. The air assist passing through the air assist passage 22 flows out through a swirler tip 23 as shown in FIG. 3. This swirler tip 23 is formed with a plurality of, or for example, four grooves 24 angularly displaced by 90° from each other, as shown in FIG. 4 so that a swirling motion can be imparted to the air assist flowing out along the periphery of the nozzle 17.
The operation of the fuel supply device 1 described above will now be described.
The coil 14 is periodically energized under control of the duty signal applied from the control unit 2 thereby causing vertical movement of the plunger 15. The resultant vertical movement of the ball valve member 16 fixed to the plunger 15 pulsates the supply of fuel fed under pressure from the fuel pump 3. Fuel is emitted from the nozzle 17 in a relation proportional to the on duration of the duty signal. Primary air supplied from the air pump 7 flows through an air pipe 19, and a swirling motion is imparted thereto by the swirler 8. Pulsating assisting air supplied from the air pump 4 flows through the air pipe 18, and a swirling motion is also imparted thereto by the grooves 24 of the swirler tip 23 before it is emitted from the air assist jet port 25. Complete atomization of fuel is achieved by the pulsating assist air emitted from the jet port 25 while making a swirling motion.
Control of the pulsation of jetted fuel and the pulsation of assist air in the fuel supply device 1 having such a structure will now be described.
First, control of the pulsation of jetted fuel will be described with reference to FIGS. 1 and 5. A read-only memory (ROM) storing a fuel jet control program is incorporated in the control unit 2, and the program is periodically started at a time interval of a predetermined period unless the control unit 2 is not in operation. In the step 51 in FIG. 5, a random access memory (RAM) storing various data and a temporary storage register are initialized. In the next step 52, data indicative of the sensed negative pressure in the intake manifold and the sensed rotation speed of the engine 9 are applied to the control unit 2, and, in the next step 53, the control unit 2 computes the exhaust pressure on the basis of the above data inputs. This computation is done by retrieving a map which has been previously stored in the ROM and represents the exhaust pressure relative to the manifold negative pressure and engine rotation speed. The data of the exhaust pressure computed in the step 53 is stored as a pressure setting in the register incorporated in the control unit 2. In the step 56, data indicative of the exhaust pressure sensed by the pressure sensor 13 is applied to the control unit 2, and, in the step 57, a determination is made as to whether or not the sensed exhaust pressure is higher than the pressure setting stored in the step 54. When the result of this determination in the step 57 is "NO", this means that clogging of the filter 10 with particulates is not so excessive as to require regeneration by combustion, and the program comes to its end. On the other hand, when the result of the determination in the step 57 is "YES", this means that clogging of the filter 10 with particulates is so excessive as to give rise to a large pressure loss, and the program proceeds to effect combustion of the particulates for the purpose of regeneration. In the step 58, data indicative of the filter temperature sensed by the temperature sensor 12 is applied to the control unit 2, and, in the next step 59, the control unit 2 computes, on the basis of this sensed temperature data and the sensed exhaust pressure data obtained in the step 56, the amount of heat required for attaining the temperature level required for combustion of the particulates. In the step 60, the flow rate of fuel and the duration of combustion required for obtaining the computed amount of heat are determined. As is commonly known in the art, a table or a map empirically prepared is retrieved for the computation of the amount of heat and determination of the flow rate of fuel. Similarly, the duration of combustion is determined on the basis of an empirically prepared table showing the relation between the filter temperature and the regeneration time. The duty factor of the duty signal is determined on the basis of the determined fuel flow rate. Then, in the step 61, the ignition signal is generated and applied to the igniter 5 so that the ignition unit 6 generates an ignition spark. In the step 62, the data of the duty factor computed in the step 60 is stored in the register in the control unit 2 so that a duty signal having a rectangular waveform is generated by a circuit well known in the art. In the step 63, a determination is made as to whether or not the emitted fuel has been ignited, on the basis of the output signal of the flame sensor 11. When the result of this determination in the step 63 is "NO", the step 63 returns to the step 61 in which the igniting operation is repeated. On the other hand, when the result of the determination in the step 63 is "YES", the step 63 proceeds to the step 64 in which a determination is made as to whether or not the combustion has been sustained over the determined duration. When the result of the determination in the step 64 is "NO", the step 64 returns to the step 62 in which the duty signal is continuously generated again to sustain combustion. On the other hand, when the result of the determination in the step 64 is "YES", this means that the regeneration of the filter 10 has been completed, and, in the step 65, generation of the duty signal is terminated, so as to end the program.
The flow rate of fuel is dependent upon both the frequency and the duty pulse width of the duty signal. Therefore, when the duty pulse width of the duty signal is set to be constant, the fuel flow rate or thermal output is proportional to the frequency of the duty signal, and fuel is emitted in the form of an intermittent stream pulsating with the same frequency as that of the duty signal. On the other hand, when the frequency of the duty signal is set to be constant, the fuel flow rate or thermal output is proportional to the duty pulse width of the duty signal. The frequency and duty pulse width of the duty signal can be determined in dependence upon the flow rate of fuel.
FIG. 6 is a block diagram showing the structure of one form of the duty signal generating circuit incorporated in the control unit 2. Referring to FIG. 6, a register 70 stores data representative of the period of the duty signal or corresponding to the frequency of the duty signal. A counter 71 counts clock pulses having a predetermined period and applied from a clock 72. When coincidence is reached between the count of the counter 71 and the data stored in the register 70, the output of a comparator 73 goes high, to set a flip-flop 74, and the Q output of the flip-flop 74 goes high, to define the leading edge of the duty pulse. At the same time, the output of the comparator 73 resets the counter 71, and the counter 71 starts to count the clock pulses again. In this manner, a pulse of the duty signal frequency appears at the output of the comparator 73. This duty frequency pulse sets another flip-flop 75, and the Q output high level from the flip-flop 75 is applied to an AND gate 76 so that the clock pulses from the clock 72 can now pass through the AND gate 76. Another counter 77 is reset in response to the application of the duty frequency pulse from the comparator 73 to count the clock pulses applied through the AND gate 76. Another register 78 stores data corresponding to the pulse width of the duty signal. When coincidence is reached between the count of the counter 77 and the data stored in the register 78, a high level output is produced from another comparator 79. This output of the comparator 79 resets the flip-flops 74 and 75, and the Q outputs of these flip-flops drop to a low level. Therefore, the duty signal having the duty frequency previously set in the register 70 and the duty pulse width previously set in the register 78 is produced at the output terminal Q of the flip-flop 74. The DC motor 34 driving the air pump 4 is shown together with a frequency difference detecting circuit 80 and a voltage generating circuit 81 which will be described later.
Control of the pulsation of an air assist will then be described. This air assist is supplied from a vane type air pump 4, well known in the art. When the vane type air pump 4 has, for example, three vanes, the air assist is pulsated three times per revolution of the vane type air pump 4. Therefore, when the rotation speed of the air pump 4 is 2,000 rpm and 4,000 rpm, the frequency of pulsation of the air assist is 100 Hz and 200 Hz respectively. Thus, a pulsation of the air assist is proportional to the rotation speed of the air pump 4. This air pump 4 is driven by the DC motor 34, and the rotation speed of the DC motor 34 can be controlled by varying its supply voltage. Accordingly, the frequency of pulsation of air assist can be controlled by controlling the voltage supplied to the DC motor 34 by the control unit 2.
A test was conducted on a Diesel-engine exhaust emission control apparatus having the construction described above, to find the combustibility and ignitability of fuel supplied from the fuel supply device 1. First, the test results showed that the relation between the amount and the particle size of fuel supplied from the fuel supply device 1 was as shown in FIG. 7. It can be seen from the test results shown in FIG. 7 that the amount of supplied fuel should be less than a certain limit in order that the particle size of emitted fuel is smaller than 80 μ. Further, the supplied fuel is generally required to be ignited within a period of time of 2 sec. FIG. 8 shows the test results showing the relation between the fuel particle size and the rate of misfire. It can be seen from the test results shown in FIG. 8 that the fuel particle size should be smaller than 50μ in order to ensure complete ignition of the fuel.
It was experimentally difficult to atomize fuel to less than 50μ in particle size when fuel was continuously emitted. The inventors have conducted research and studies on this point and found that fuel can be sufficiently and stably atomized effectively by discontinuously emitting the fuel and pulsating the air assist. The inventors have also found that the degree of atomization of fuel can be markedly improved when the frequency of the duty signal applied for emitting of fuel and the pulsation frequency of the air assist are selected to be equal to each other or there is a linear relation therebetween as shown in FIG. 9. FIG. 10 shows the relation between the frequency of the duty signal and the rotation speed of the air pump 4 when the rotation speed of the air pump 4 providing the best combustibility relative to various values of the frequency of the duty signal controlling the fuel supply was experimentally sought and plotted. Since the air pump 4 is of the three vane type, the pulsation frequency of the air assist is 100 Hz and 200 Hz when the rotation speed of the air pump 4 is 2,000 rpm and 4,000 rpm respectively. Thus, as in the case of FIG. 9, the pulsation frequency of assisting air is proportional to the frequency of the duty signal in FIG. 10. That is, the best atomization of fuel is achieved and the best combustibility is also achieved when the pulsation frequency of the air assist and the frequency of the duty signal have the relation shown in FIG. 9. For achieving the above condition, the frequency difference detecting circuit 80 shown in FIG. 6 detects the frequency difference between the output signal of the comparator 79 resetting the flip-flop 74 generating the duty signal and the signal indicative of the rotation speed of the DC motor 34, and, on the basis of the detected frequency difference, the voltage generating circuit 81 shown in FIG. 6 applies a control voltage to the DC motor 34 so that the pulsation frequency of the air assist becomes equal to the frequency of the duty signal.
The above description applies referred to the case where fuel emitted from the fuel supply device 1 is ignited and burned in space to produce high-temperature gas which is introduced into the filter 10 to burn particulates collected by the filter 10 thereby regenerating the filter. In another embodiment of the present invention, the filter 10 has a three-dimensional net structure having a coating of a catalyst, and atomized fuel is directly introduced into such a filter 10 so that fuel is burned in the filter 10 by the function of the catalyst to cause combustion of particulates thereby regenerating the filter 10. In this case, the ignition unit 6 and the flame sensor 11 are unnecessary. In the embodiment using the filter 10 having the catalyst coating also, high-temperature gas produced as a result of combustion of emitted fuel in space may be introduced into the filter.
It will be apparent from the foregoing detailed description that the Diesel-engine exhaust emission control apparatus according to the present invention can sufficiently atomize fuel thereby ensuring complete combustion of fuel. | An exhaust emission control apparatus for a Diesel engine includes a filter collecting particulates contained in exhaust gases of the Diesel engine and a fuel supply device supplying fuel required for burning the collected particulates. The fuel supply device controls the amount of supplied fuel so that the temperature of the filter can be raised to a level high enough for burning the collected particulates but not so high as to damage the filter itself by the heat applied thereto. A control unit executes the fuel control on the basis of the temperature of the filter and the pressure drop across the filter. | 8 |
TECHNICAL FIELD
The present invention relates to an ultrasonic flaw detector for inspecting the surface condition of a specimen or the existence or non-existence of one or more internal defects in the specimen by radiating ultrasonic waves to scan the specimen and then analyzing waves reflected by the specimen.
BACKGROUND ART
Ultrasonic flaw detectors can detect internal defects of specimens without destruction of the specimens and are employed in many fields. The existence or non-existence of a defect inside a specimen is checked over a predetermined area of the specimen in many instances. In this case, the inspection is conducted by scanning the above-described area of the specimen with ultrasonic waves radiated from a probe. Actually employed as such a probe includes an array probe constructed of many piezoelectric elements arranged in a line. An ultrasonic flaw detector making use of such an array probe will hereinafter be described.
FIG. 1 is a perspective view of a scanner unit of the conventional ultrasonic flaw detector. FIGS. 2(a) and 2(b) are plan and side views of an array probe, respectively. In each of the drawings, there are shown a water tank 1 for inspection, water 2 charged in the water tank 1, and a specimen 3 placed on the bottom wall of the water tank 1. Designated at numeral 4 is a scanner, which is constructed of the following members: a scanner table 5 on which the water tank 1 is mounted, frames 6 fixed on the scanner table 5, an arm 7 extending between the frames 6, a holder 8 mounted on the arm 7, a pole 9 pendant from the holder 8, and an array probe 10. The frames 6 can move the arm 7 in the direction of Y-axis by an unillustrated mechanism, while the arm 7 can move the holder 8 in the direction of Y-axis by a mechanism which is free of illustration. Further, the holder 8 can move the array probe 10 in the direction of Z-axis (the direction perpendicular to X-axis and also to Y-axis) in association with the pole 9 by means of a mechanism (not shown).
The array probe 10 is constructed of a number of minute piezoelectric elements (hereinafter called "array elements") arranged in a line. The direction of arrangement of the array elements is in conformance with the direction of X-axis. Whenever a pulse is applied, each array element radiates an ultrasonic wave and then converts a reflected wave of the ultrasonic wave by the specimen 3 to a corresponding electrical signal. The individual array elements are indicated by numerals 10 1 -10 n in FIGS. 2(a) and 2(b), in which dots indicate points of sampling. Symbol YP indicates the sampling pitch in the direction of Y-axis, while symbol XP represents the sampling pitch in the direction of X-axis. In addition, symbol AP shows the pitch between the adjacent array elements 10 1 -10 n . Designated at numeral 11 is a casing in which the array probe 10, etc. are accommodated.
Here, the function of the array probe 10 shown in each of the above drawings is described in brief with reference to FIGS. 3(a) and 3(b). In FIG. 3(a), there are illustrated array elements T 1 -T 9 arranged in a line, delay elements D 1 -D 9 connected to the respective array elements T 1 -T 9 , and pulses p to be inputted to the respective array elements T 1 -T 9 . The delay elements D 1 ,D 9 have been set at the same delay time (t 19 ). Likewise, the delay elements D 2 ,D 8 at the same delay time (t 28 ), the delay elements D 3 ,D 7 at the same delay time (t 37 ), and the delay elements D 4 ,D 6 at the same delay time (t 46 ). The relationship among the delay times thus set can be expressed by the following inequality:
t.sub.19 <t.sub.28 <t.sub.37 <t.sub.46 <t.sub.5 ( 1)
where t 5 stands for the delay time of the delay element D 5 .
Now, the delay times of the individual delay elements D 1 - 9 are set at desired values while maintaining the relationship of the inequality (1), and the pulses p are inputted. From the array elements T 1 -T 9 , ultrasonic waves are then radiated in accordance with the delay times so set, i.e., first from the array elements T 1 ,T 9 and last from the array element T 5 . The ultrasonic waves radiated in the above manner then advance radially and inwardly, so that there is a point where the maximum amplitudes of oscillations of the ultrasonic waves radiated from the respective array elements all coincide. This point is indicated by letter F in FIG. 3(a). Since the magnitude of the resulting ultrasonic wave is far greater at the point F compared to that of ultrasonic wave at any other point, the ultrasonic waves from the respective array elements T 1 -T 9 become as if converged at the point F as indicated by dashed lines. In other words, the application of suitable delays to the radiation of ultrasonic waves from respective array elements arranged in a line can develop a situation similar to the convergence of such ultrasonic waves at the point F. This point F will therefore be called "the point of convergence". Described further, the array elements T 1 -T 9 outputs an ultrasonic beam B which converges at the point F of convergence as indicated by the dashed lines. If the respective delay times are set shorter than the above-described delay times while maintaining the relationship of the inequality (1), the point F of convergence is shifted to a farther point F' of convergence as indicated by alternate long and short dash lines (beam B'). It is therefore possible to select the position of the point of convergence by adjusting the delay times of the individual delay elements D 1 -D 9 . When used for the inspection of the specimen 3, the depth of the point of inspection can be selected.
FIG. 3(b) is a schematic illustration of the function of the array probe 10 shown in FIGS. 2(a) and 2(b). In the drawing, numerals 10 1 -10 n indicate the same array elements as depicted in FIG. 2(a). Delay elements are connected to the individual array elements 10 1 -10 n although not illustrated. In the illustrated example, m pieces of array elements 10 1 -10 m are first selected and the delay times of ultrasonic waves to be radiated from the array elements are set appropriately, whereby the ultrasonic waves are apparently caused to converge at one point of convergence as described above. In FIG. 3(b), this point of convergence and an apparent ultrasonic beam are indicated by symbols F 1 and B 1 , respectively. Next, the vibration of array elements is shifted by one element so that delay times of the same pattern as the delay times applied to the array elements 10 1 -10 m in the preceding vibration are applied to the m pieces of array elements 10 2 -10 m+1 . For this vibration, the point of convergence is indicated by symbol F 2 while the resulting ultrasonic beam is designated by symbol B 2 . Thereafter, the vibration of array elements is shifted successively one by one. The array elements 10 n-m+1 -10 n are finally selected, to which delay times of the same pattern are applied to obtain a point F n-m+1 of convergence and an ultrasonic beam B n-m+1 . As a consequence, ultrasonic scanning can be performed from the point F 1 of convergence to the point F n-m+1 of convergence by the array probe 10 in the manner described above. The scanning will hereinafter be called "electronic scanning" as it is electronically performed at a high speed. In FIG. 3(b), AP and SP indicate the pitch of the array elements and the sampling pitch, respectively. They are equal to each other in the illustrated example.
A description will next be made of a control unit of the ultrasonic flaw detector making use of the array probe described above. In this description, assume by way of example that an area of a specimen, said area being to be inspected, has a length of 120 mm in the direction of X-axis, the array probe 10 is equipped with 128 array elements, the pitch of the array elements is 1 mm, eight array elements are vibrated at the same time, and the scanning of the specimen is performed with 121 beams in the direction of X-axis. FIG 4 shows the arrangement of the above array elements, in which there are illustrated the array probe 10, array elements 10 1 -10 128 and ultrasonic beams B 1 -B 121 . The individual array elements 10 1 -10 128 are indicated by numerals 1-128 in the drawing. The control unit is indicated at numeral 11.
FIG. 5 is a block diagram of the control unit 11 shown in FIG. 4. In the drawing, numeral 10 indicates the array probe. Designated at numeral 12 is a microprocessor, while numeral 13 indicates a transmission delay circuit for delaying, by predetermined times, vibration of the individual array elements which are adapted to give off ultrasonic beams B 1 -B 121 , respectively. Only one transmission delay circuit 13 is provided for the individual ultrasonic beams B 1 -B 121 . There are also illustrated a matrix circuit 14 and a distributor 15. They are provided to use the transmission delay circuit 13 commonly for the respective ultrasonic beams B 1 -B 121 . Designated at numeral 16 is a transmit-receive circuit, which outputs vibrating pulses to the individual array elements 10 1 -10 128 of the array probe 10 and also receives signals of reflection waves from the individual array elements 10 1 -10 128 . The constructions of the matrix circuit 14, distributor 15 and transmit-receive circuit 16 will be described in further detail with reference to FIG. 6, FIG. 7 and FIG. 8. Designated at numeral 17 is a shift register, which serves to successively connect the transmit-receive circuit 16 to groups of eight array elements, each group being to be employed to form a single ultrasonic beam. Numeral 18 indicates an adder having the same construction as the distributor 15 except that the input and output are opposite, and numeral 19 designates a matrix circuit of the same construction as the matrix circuit 14. Designated at numeral 20 is a waveform adder, which brings into coincidence the phases of eight signals outputted from the matrix circuit, followed by the addition. Each output of the waveform adder 20 is processed suitably and then displayed in a desired mode. Based on the output thus displayed, it is determined whether the specimen contains a defect or not.
The operation of the control circuit 11 will next be described with successive reference to FIG. 6, FIG. 7 and FIG. 8.
(I) Operations of the Transmission Delay Circuit 13 and Matrix Circuit 14
FIG. 6 is a circuit diagram around the matrix circuit 14, in which elements identical to their corresonding elements in FIG. 5 are indicated by like reference numerals. Capital letters A-H indicate output terminals of the transmission delay circuit 13, while small letters a-h show input terminals of the distributor 15. The transmission delay circuit 13 is equipped with eight delay elements similar to those depicted in FIG. 3(a). These eight delay elements correspond to eight array elements which form a single ultrasonic beam.
To have the ultrasonic beam form a point of convergence at an optimum position, the delay times of the eight delay elements are set by the microprocessor 12. Upon subsequent energization of transmission delay circuit 13, successively delayed pulses are outputted from the respective output terminals A-H. In this case, the individual output terminals A-H correspond to the eight array elements in the order of arrangement, which array elements are adapted to form an ultrasonic wave. The delay time is the shortest in the case of the output pulses from the terminals A,H and then becomes successively longer in the order of the terminals B,G, the terminals C,F and the terminals D,E.
The matrix circuit 14 is of the same construction as those employed generally. It is constructed of eight input lines from the transmission delay circuit 13, eight output lines crossing with the input lines, and switching elements (not shown) for selectively connecting the crossing input and output lines. 64 (8×8) switching elements are provided. Their switching operation is controlled by the microprocessor 12. Further, the eight output lines are connected to the input terminals a-h of the distributor 15, respectively.
Now assume that by a command from the microprocessor 12, the switching elements indicated by squares in the matrix circuit 14 have been switched into a conductive state and the other switching elements have been brought into a non-conductive state. The output terminals A-H of the transmission delay circuit 13 are successively connected to the input terminals a-h of the distributor 15. As a result, a first combination of delay times is established with the shortest delay time being set for the input terminals a,h and the longest delay time being set for the input terminals d,e. This first combination corresponds to the combination of the array elements 10 1 -10 8 which forms the first ultrasonic beam B 1 .
When the microprocessor 12 brings only the switching elements at triangles into a conductive state, the terminals A-H are successively connected to the terminals b-h,a. Accordingly, a second combination is established with the shortest time set for the terminals b,a and the longest time set for the terminals e,f. This second combination corresponds to the combination of the array elements 10 2 -10 9 which forms the ultrasonic beam B 2 . When the switching elements only at circles are brought into a conductive state, is established a third combination corresponding to the combination of the array elements 10 3 -10 10 which forms an ultrasonic beam B 3 . As the switching elements are then successively actuated in a similar manner, up to eight combinations are established over the input terminals a-h. The next, i.e., the ninth combination has the same delay time as the first combination. Such combinations are continually and repeatedly established.
(II) Operation of the Distributor 15
FIG. 7 is a circuit diagram showing the circuit construction of the distributor 15. In the drawing, a-h indicate the same input terminals of the distributor 15 as those depicted in FIG. 6. Further, numerals 1-128 indicate the 1st-128th output terminals of the distributor 15. These output terminals corresponding to the array elements 10 1 -10 128 , respectively. Delay pulses inputted to the input terminal a are distributed, as shown in the drawing, to the 1st-121th output terminals connected to the input terminal a. Similarly, delay pulses inputted to the input terminals b-h are distributed to the illustrated individual output terminals connected thereto. As will be described subsequently, the 1st-128th output terminals are connected to corresponding trigger circuits which serve to trigger corresponding pulsers in the transmit-receive circuit 16. These trigger circuits are rendered conductive successively 8 circuits by 8 circuits, the eight circuits in each group being brought into a conductive state at the same time, while shifting one circuit by one circuit this conversion of the trigger circuits into the conductive state. Accordingly, only the successive eight output terminals among the entire output terminals effectively output delay trigger signals. Taking the individual input terminals a-h by way of example, only one of the output terminals connected to these input terminals always outputs a delay trigger signal.
When the beam B 1 is formed by the array elements 10 1 -10 8 for example, the trigger circuits connected to the 1st-8th output terminals are brought into a conductive state so that pulses of the shortest delay time are outputted from the 1st and 8th output terminals while pulses of the longest delay time are outputted from the 4th and 5th output terminals. When the beam B 2 is next formed by the array elements 10 2 -10 9 , the trigger circuits connected respectively to the 2nd-9th output terminals are then brought into a conductive state. On the other hand, concurrent with this, the actuation of the matrix circuit 14 depicted in FIG. 6 moves from the switching elements at the positions of the squares to the positions of the triangles, whereby the latter switching elements are brought into a conductive state. Therefore, pulses of the shortest delay time are inputted to the input terminals b,a and pulses of the longest delay times are inputted to the input terminals e,f. As a result, pulses of the shortest delay time are outputted to the 2nd and 9th output terminals while pulses of the longest delay time are outputted to the 5th and 6th output terminals, respectively.
In this manner, conduction of the trigger circuits connected to the respective output terminals is shifted one circuit by one circuit and at the same time, the delay times of the input terminals a-h are also shifted one by one. Accordingly, the eight array elements employed to form an ultrasonic beam are always vibrated with the delay times satisfying the relationship of the inequality (1).
(III) Operations of the Transmit-Receive Circuit 16 and Shift Register 17
FIG. 8 is a circuit diagram around the transmit-receive circuit 16, in which elements identical to the corresponding elements shown in FIG. 5 are identified by like symbols. There are shown AND gates X 1 -X 128 , pulsers P 1 -P 128 , and receivers R 1 -R 128 . One AND gate, one pulser and one receiver are provided for each of the array elements 10 1 -10 128 . One input terminals of the AND gates X 1 -X 128 are connected to the 1st-128th output terminals of the distributor 15, and the other input terminals are connected to the 1st -128th output terminals of the shift register 17. As described above in the description of the operation of the distributor 15 in (II), the AND gates X 1 -X 128 make up the trigger circuits which trigger the pulsers P 1 -P 128 , respectively. The 1st-128th output terminals of the shift register 17 are connected to the AND gates X 1 -X 128 as described above and also to the receivers R 1 -R 128 . On the other hand, the output terminals of the receivers R 1 -R 128 are connected to the corresponding 1st -128th input terminals of the adder 18.
In accordance with a command from the microprocessor 12, the shift register 17 simultaneously outputs pulses from eight consecutive output terminals and shifts the output of pulses one terminal by one terminal. Now assume that the ultrasonic beam B 1 is to be formed by the array elements 10 1 -10 8 . Pulses are outputted from the 1st-8th output terminals of the shift register 17, whereby one input terminals of the AND gates X 1 -X 8 are changed to a high level. At the same time, the receivers R 1 -R 8 are triggered so that these receivers are brought into an activated state. At this time, pulses delayed by prescribed times as described above are outputted from the 1st-8th output terminals of the distributor 15. The other input terminals of the AND gates X 1 -X 8 take a high level after the pulse delay times for the 1st-8th terminals of the distributor 15. At this time point, the AND gates are brought into a conductive state so that trigger signals adapted to trigger the corresponding pulsers are outputted. As already mentioned above in the description of the distributor 15, the outputs from the first and eighth output terminals take place first and the output from the fifth output terminal occurs last. The outputs of pulses form the pulsers P 1 -P 8 also occur correspondingly. As a consequence, the array elements 10 1 ,10 8 are vibrated first and the array elements 10 4 ,10 5 are vibrated last, so that the desired ultrasonic wave B1 is formed.
Upon radiation of the ultrasonic beam B 1 against the specimen, reflected waves enter the individual array elements 10 1 -10 8 so that they are converted to corresponding electrical signals. Signals of reflected waves outputted from the respective array elements 10 1 -10 8 in the above manner are separately amplified by the receivers R 1 -R 8 and then inputted to the 1st-8th input terminals of the adder 18, respectively. In this case, needless to say, among the reflected waves entering the respective array elements 10 1 -10 8 , the entering of the reflected waves in to the array elements 10 1 ,10 8 take place first while that of the reflected waves into the array elements 10 4 ,10 5 occur last. Accordingly, the signals of reflected waves to be inputted to the 1st and 8th input terminals of the adder 18 are outputted first while the reflected wave signals to be inputted to the 4th and 5th input terminals are outputted last.
Subsequent to the formation of the ultrasonic beam B 1 , the outputs from the shift register 17 are shifted by one output terminal so that pulses are outputted from the eight output terminals numbered from the 2nd to the 9th. Further, the delay pattern of delay pulses which appear at the output terminals of the distributor 15 is also shifted by one output terminal. Namely, delay pulses are outputted with the shortest delay time from the 2nd and 9th output terminals while delay pulses are outputted with the longest delay time from the 4th and 5th output terminals. As a result, the array elements 10 2 -10 9 are vibrated with the corresponding delay times so that the desired ultrasonic beam B 2 is formed. Signals of resulting reflected waves are amplified by the corresponding receivers R 2 -R 9 and are then inputted to the 2nd-9th input terminals of the adder 18 with time intervals corresponding the delay times. In a similar manner, reflected wave signals are then successively inputted to the input terminals of the adder 18.
(IV) Operations of the Adder 18, Matrix Circuit 19 and Waveform Adder 20
As illustrated in FIG. 8, the adder 18 is provided with 1st-128th input terminals which are connected to the receivers R 1 -R 128 , respectively. Incidentally, the adder 18 has the same circuit construction as the distributor 15 except that the input-output relationship is opposite. Therefore, the 1st-128th terminals in FIG. 7 correspond to the input terminals of the adder 18 and the terminals a-h correspond to output terminals of the adder 18. As is apparent from the foregoing, it is only the consecutive eight receivers that reflected wave signals are inputted. Of the 128 input terminals of the adder 18, it is only the consecutive eight input terminals that reflected wave signals are inputted. A signal of reflected wave is therefore inputted to only one of the input terminals which are associated with the output terminals a-h.
A description will next be made using the preceding example. When the ultrasonic beam B 1 is radiated, reflected wave signals are inputted to the 1st-8th input terminals of the adder 18 and these signals are then outputted, as they are, from the output terminals a-h. When the ultrasonic beam B 2 is radiated on the other hand, reflected wave signals are inputted to the 2nd-9th input terminals of the adder 18 and are then outputted, as they are, from the output terminals a-h.
The matrix circuit 19 has the same circuit construction as that shown in FIG. 6 except that the output terminals and input terminals are opposite. Namely, the input terminals of the matrix circuit 19 correspond to the terminals a-h shown in FIG. 6. These input terminals a-h are connected to the corresponding ones of the output terminals a-h of the adder 18. The manner of switching of the individual switching elements of the matrix circuit 19 are the same as the manner of switching of the matrix circuit 14. Assume that signals of reflected waves of the ultrasonic beam B 1 are inputted to the input terminals a-h. Among the switching elements of the matrix circuit 19, those located at the points of squares shown in FIG. 6 are switched into a conductive state. These signals of reflected waves are therefore outputted from the corresponding output terminals A-H. Similarly, when signals of reflected waves of the ultrasonic beam B 2 are inputted to the input terminals a-h, the switching elements at the points of triangles are brought into a conductive state so that the signals of reflected waves at the input terminals a-h are outputted from the output terminals H,A-G, respectively.
Regarding the ultrasonic beams B 1 , B 2 and B 3 , the relationship among the signals of their reflected waves at the input terminals in the adder 18 and at the input terminals and output terminals in the matrix circuit 19 can be illustrated as shown in the following table.
______________________________________Ultrasonic beam B.sub.1 B.sub.2 B.sub.3______________________________________Input terminals of adder 18 1-8 2-9 3-10Input terminals of matrix a-h b-a c-bcircuit 19Output terminals of matrix A-H A-H A-Hcircuit 19______________________________________
As is apparent from the above table, the reflected wave signals from the vibrated consecutive eight array elements are always outputted from the output terminals A-H of the matrix circuit 19 in the order of arrangement of the array elements no manner how these array elements are selected.
The reflected wave signals outputted from the output terminals A-H are inputted to the waveform adders 20, respectively. The waveform adders 20 are equipped with delay circuits, which are connected respectively to the above output terminals, and also with an addition circuit for adding reflected wave signals outputted from these delay circuits, although neither the delay circuits nor the addition circuit is shown in the drawing. The respective delay circuits are provided to bring the phases of reflected wave signals, said phases being different from one another, into coincidence and add the individual reflected wave signals in the same phase at the above addition circuit. In accordance with the inequality (1), reflected wave signals are outputted last from both the end elements of the eight array elements and reflected wave signals are outputted first from the central array elements. Therefore, the delay time of the delay circuits connected to the output terminals A,H of the matrix circuit 19 are the shortest and the delay time of the delay circuits connected to the output terminals D,E is the longest. When suitable delay times are set for the individual delay circuits in the manner described above, the phases of reflected wave signals outputted from these delay circuits are coincided so that these reflected wave signals are added in the same phase at the addition circuit.
The operation of the control circuit 11 has been described above. Outputs from this control circuit 11 are signals of reflected waves of the individual ultrasonic beams. Based on the reflected wave signals, the existence or non-existence of one or more defects in a specimen is determined. A description will hereinafter be made of one example of processing suitable for the above determination.
Each signal of reflected wave obtained at the control circuit 11 is inputted to a peak detector to detect its peak value. After the peak value so detected is then converted to a digital value by an A/D converter, the digital value is inputted to an image processor. At the image processor, it is judged whether the peak value is greater than a preset threshold or not. To a display, the image processor outputs, for example, a low-level signal when the peak value is greater than the threshold and a high-level signal when the peak value is not greater than the threshold. As a result, the display gives, for example, a black-level display when no defect is present or a white-level display when a defect is present. Since similar processing is performed for each beam, the existence or non-existence of a defect in an entire planar cross-section at a given depth of a specimen is clearly displayed as a plan by electronic scanning with the ultrasonic beams B 1 -B 121 from the array probe 10 in the direction of X-axis and by mechanical scanning in which the array probe 10 is moved in the direction of Y-axis.
The above-described conventional ultrasonic flaw detector can inspect with extreme certainty the existence or non-existence of a defect in a specimen. There is a strong desire for a still faster inspection speed where many specimens are inspected by the above ultrasonic flaw detector. The inspection speed of the ultrasonic flaw detector is however governed by the time required for one electronic scanning operation, namely, by (the number of ultrasonic beams) x (switching speed). Here, the switching speed is usually set equal to the repetition speed (frequency) of the pulsers which are adapted to vibrate array elements. It is therefore difficult to shorten the above time, resulting in the problem that as the area of a specimen to be inspected in the direction of X-axis (the direction of electronic scanning) becomes greater, more ultrasonic beams are required and naturally a longer inspection time is needed.
An object of the present invention is therefore to overcome the above-described problem of the prior art and to provide an ultrasonic flaw detector capable of substantially shortening the electronic scanning time, in other words, the inspection time for a specimen.
SUMMARY OF THE INVENTION
To achieve the above object, the present inventors firstly contemplated of dividing array elements into blocks of plural array elements and providing each block with a control unit similar to those employed in the conventional detector. This approach however developed another problem that ultrasonic beams were unavoidably omitted between the adjacent blocks since plural array elements were used for the formation of each ultrasonic beam. The present inventors have then proceeded with a further investigation, resulting in the invention of a means for substantially shortening the electronic scanning time without such omission of ultrasonic beams. Namely, the present invention provides an ultrasonic flaw detector having an array probe formed of a number of array elements arranged in a line, pulsers for feeding delay pulses to plural ones of the array elements to vibrate the plural array elements, and receivers for receiving signals of reflected wave of an ultrasonic beam by the plural array elements, vibration of said array elements being successively shifted to conduct scanning by ultrasonic beams, characterised in that the entire array elements are divided into plural blocks with groups of some of said array elements overlapping between adjacent ones of the plural blocks, and each of the blocks is provided with a block selecting means for selecting plural ones of the array elements in the same block and shifting vibration of the array elements in the same block, an input/output unit for receiving signals from individual receivers for the same block and outputting the thus-inputted signals, and a switching means for causing the array elements in each of the groups to belong first to one of the same block and an adjacent one of the blocks and then to the other block.
In the above construction, the many array elements arranged in a line are divided into the plural blocks. The pulsers and receivers, which are connected to these array elements, are also divided into the same blocks. When delay pulses are outputted from plural ones of the pulsers in each block thus divided, the array elements connected to these pulsers are vibrated to radiate an ultrasonic beam. These array elements then receive its reflected waves and output reflected wave signals. These reflected wave signals are fed through the receivers connected to the vibrated array elements, inputted to the corresponding input/output terminals of the input/output unit, and then outputted together. In the invention, the array elements in each overlapped group is caused by a switching means to belong first to one of the associated blocks and then to the other block. This switching has made it possible to avoid omission of ultrasonic beams between blocks.
Vibration of plural array elements in each block is shifted one element by one element. As a result, electronic scanning with ultrasonic beams can be performed in each block. Reflected wave signals as many as the blocks are hence collected at the same time per line, leading to a substantial reduction in the electronic scanning time.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a scanner unit of a conventional ultrasonic flaw detector;
FIGS. 2(a) and 2(b) are plan and side views of an array probe;
FIGS. 3(a) and 3(b) are schematic illustrations showing the function of the array probe;
FIG. 4 shows the arrangement of array elements;
FIG. 5 is a block diagram of a control unit shown in FIG. 4;
FIGS. 6, 7 and 8 are circuit diagrams of a matrix circuit, distributor and transmit-receive circuit depicted in FIG. 5;
FIG. 9 a block diagram of a control unit of an ultrasonic flaw detector according to one embodiment of the present invention;
FIG. 10 illustrates the arrangement of array elements;
FIGS. 11(a), 11(b), 11(c) and 11(d) are circuit diagrams of an adder/switching circuit shown in FIG. 9;
FIG. 12 shows various data;
FIG. 13 is a circuit diagram of an adder of an ultrasonic flaw detector according to another embodiment of the present invention; and
FIGS. 14(a), 14(b), 14(c) and 14(d) are circuit diagrams of a matrix circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
To describe the present invention in more detail, the invention will now be described with reference to the accompanying drawings.
FIG. 9 is a block diagram of an ultrasonic flaw detector according to one embodiment of the present invention, and FIG. 10 shows the arrangement of array elements and illustrates the concept of a method for vibrating the array elements in the embodiment depicted in FIG. 9. In this embodiment, similarly to the examples described above, a description will be made assuming that the number of the array elements, the pitch of the array elements, the number of array elements vibrated at the same time, and the number of ultrasonic beams are 128, 1 mm, 8 and 121.
First of all, the concept of the vibration method in this embodiment is described with reference to FIG. 10. FIG. 10 shows an array probe 10 and array elements 10 1 -10 128 , which are the same as the conventional ones. Designated at numeral 25 is a control circuit in the present embodiment. Its construction is illustrated in FIG. 9. In this embodiment, upon vibration of the array elements, the 128 array elements are divided into 4 blocks K 1 , K 2 , K 3 and K 4 . Symbols K 12 , K 23 and K 34 indicate boundary sections where the blocks are overlapped. Namely, the individual blocks K 1 -K 4 are set with some of the array elements being shared. Further, the array elements in each of these boundary sections K 12 ,K 23 ,K 34 are vibrated by causing them to belong to one of the adjacent blocks during a prescribed time period in each electronic scanning period and to the other block during another time period.
Described more specifically, the blocks K 1 , K 2 , K 3 and K 4 are constructed of array elements 10 1 -10 40 , array elements 10 33 -10 72 , array elements 10 65 -10 104 and array elements 10 97 -10 128 , respectively. On the other hand the boundary sections K 12 , K 23 and K 34 are constructed, of array elements 10 33 -10 40 , array elements 10 65 -10 72 and array elements 10 97 -10 104 . Upon electronic scanning, the boundary sections K 12 ,K 23 ,K 34 are first caused to belong to the blocks K 2 , K 3 and K 4 to take part in the formation of ultrasonic beams. Thereafter, they are caused to belong to the blocks K 1 , K 2 , and K 3 to take part in the formation of ultrasonic beams. Namely, the electronic scanning are first initiated simultaneously by a beam B 1 from the block K 1 , a beam B 33 from the boundary section K 12 caused to belong to the block K 2 , a beam B 65 from the boundary section K 23 caused to belong to the block K 3 and a beam B 97 from the boundary section K 34 caused to belong to the block K 4 .
When the electronic scanning advances in a direction indicated by arrows in FIG. 10 and the use of the array elements in the boundary sections K 12 ,K 23 ,K 34 for the formation of the ultrasonic beams is completed, the boundary sections K 12 ,K 23 ,K 34 are then caused to belong to the blocks K 1 ,K 2 ,K 3 respectively at a suitable time. The array elements in these boundary sections then take part along with the array elements in the blocks, to which the boundary sections belong, in the formation of ultrasonic beams for the continuation of the electronic scanning. Eventually, the electronic scanning is completed by the radiation of an ultrasonic beam B 32 formed by the eight array elements ranging from the array element 10 32 in the block K 1 to the array element 10 39 in the boundary section K 12 , an ultrasonic beam B 64 formed by the eight array elements ranging from the array element 10 64 in the same block K 2 to the array element 10 71 in the boundary section K 23 , an ultrasonic beam B 96 formed by the eight array elements ranging from the array element 10 96 in the block K 3 to the array element 10 103 in the boundary section K 34 , and an ultrasonic beam B 121 formed by the eight array elements ranging from the array element 10 121 to the array element 10 128 in the block K 4 . It is therefore possible to obviate the omission of ultrasonic beams, which takes place between the adjacent blocks when the array probe is divided simply into 4 blocks. A description will hereinafter be made of a construction for conducting such electronic scanning.
In the block diagram shown in FIG. 9, the same elements of structure as the corresponding elements depicted in FIG. 5 are indicated by like symbols and their description is omitted herein. Numeral 25 indicates the control circuit in this embodiment. There are also shown a microprocessor 26, a transmit-receive circuit 27, and a shift register 28. They have substantially the same constructions as the microprocessor 12, transmit-receive circuit 16 and shift register 17 except that the array probe 10 is operated as the above-described blocks. Further, the microprocessor 26 is different in that it performs control of switching elements, which will be described subsequently herein, in addition to the control of the blocks. Designated at numeral 29 is an adder/switching circuit, whose construction will also be described subsequently herein. There are also shown matrix circuits 19K 1 -19K 4 and waveform adders 20K 1 -20K 4 . They have the same functions as the matrix circuit 19 and waveform adder 20 depicted in FIG. 5.
FIG. 11(a) is a circuit diagram of the adder/switching circuit shown in FIG. 9. In the drawing, there are shown input terminals 1-128 of the adder/switching circuit 29, adders W 11 -W 48 , and switches S. Corresponding to the array probe 10, the adder/switching circuit 29 is also divided into blocks K 1' -K 4' and intermediate sections K 12' ,K 23' ,K 34' as shown in the drawing. Namely, the block K 1' comprises the adders W 11 -W 18 . The 1st-32th input terminals are connected to the adders W 11 -W 18 in the arrangement illustrated in the drawing. Further, to the individual adders W 11 -W 18 , ones of switching terminals of the respective switches S are connected along with the corresponding input terminals. The remaining blocks K 2' -K 4' also have a similar construction. On the other hand, the intermediate section K 12' , comprises the 33rd-40th input terminals, which are connected to the corresponding switches S. The remaining intermediate sections K 23' ,K 34' have a similar construction. All the switches S are arranged in such a way that they can be switched over in an interlocked manner by a command from the microprocessor 26. By this switching, a selection is made regarding the blocks to which the input terminals making up the respective intermediate sections are caused to belong as input terminals of the corresponding adders.
Incidentally, no more than one signal is simultaneously inputted through the individual input terminals of each adder, as will be described subsequently. Since signals inputted to the remaining input terminals are all zero, each adder is merely a connector means that outputs a signal which has been inputted through anyone of the input terminals as is.
Next, the operation of this embodiment will be described with reference to the circuit diagrams of the adder/switching circuit 29, which circuit diagrams are illustrated in FIGS. 11(a)-11(d). First, the switches S of the adder/switch circuit 29 are switched to their respective positions shown in FIG. 11(a). The intermediate sections K 12' ,K 23' ,K 34' are therefore caused to belong to the blocks K 2' ,K 3' ,K 4' , respectively. The operation is the same as that of the conventional detector until delay pulses are outputted from the distributor 15. In this embodiment, in accordance with commands from the microprocessor 26, signals are outputted from the 1st-8th output terminals, 33rd-40th output terminals, 65th-72nd output terminals and 97th-104th output terminals, respectively. Thereafter, the output from the output terminals of the shift register 28 is shifted one terminal by one terminal successively. Namely, the output terminals of the shift register 28 are divided into four blocks which consist of the 1st-40th output terminals, the 33rd-72nd output terminals, the 65th-104th output terminals and the 97th-128th output terminals, respectively. In each block, signals are simultaneously outputted from eight output terminals. The output from the output terminals is shifted. The division of the array elements into blocks by the shift register 28 is not changed once the direction of electronic scanning is determined. It is here that this division is different from the division into the blocks upon vibration, the latter division being shown in FIG. 10. By signals from the 1st-8th, 33rd-40th, 65th-72nd and 97th-104th output terminals, the shift register 28 triggers the corresponding pulsers of the transmit-receive circuit 27 so that the corresponding array elements are vibrated. In addition, the corresponding receivers are actuated. The four ultrasonic beams B 1 ,B 33 ,B.sub. 65,B 97 are then radiated from the array probe 10. Reflected waves of the these ultrasonic beams B 1 ,B 33 ,B 65 ,B 97 enter the vibrated array elements and are inputted as signals of reflected waves to the actuated receivers.
Reflected wave signals outputted from the receivers are inputted to the adder/switching circuit 29. In this case, the input terminals of the adder/switching circuit 29, to which the reflected wave signals are inputted, correspond to the vibrated array elements and actuated receivers. These input terminals are indicated by surrounding them in squares in FIG. 11(a). The reflected wave signals, which have been inputted to these input terminals, are outputted as signals of the corresponding adders because there are no inputs to the other input terminals of these adders. Namely, the input signals to the 1st-8th input terminals are outputted as they are from the adders W 11 -W 18 , the input signals to the 33rd-40th input terminals from the adders W 21 -W 28 , the input signals to the 65th-72nd input terminals from the adders W 31 -W 38 , and the input signals to the 97th-104th input terminals from the adders W 41 -W 48 .
The output signals from the adders W 11 -W 18 , namely, the eight output signals from the block K 1' are inputted via the matrix circuit 19K 1 to the waveform adder 20K 1 . After the phases of the eight reflected wave signals brought into coincidence by unillustrated delay circuits respectively, these reflected wave signals are added by the corresponding adder. This operation is the same as the operation of the matrix circuit 19 and waveform adder 20 in the conventional detector. The eight reflected wave signals outputted from each of the blocks K 2' -K 4' are likewise processed by the matrix circuits 19K 2 -19K 4 and waveform adders 20K 2 -20K 4 . As a result, the existence or non-existence of a defect at four points of the specimen based on the signals of reflected waves of the ultrasonic beams B 1 ,B 33 ,B 65 ,B 97 are displayed at the same time, for example, on a display of an image processor.
The output of signals from the output terminals of the shift register 28 is next shifted by one output terminal, so that signals are outputted from the 2nd-9th, 34th-41st, 66th-73rd and 98th-105th output terminals. Ultrasonic beams B 2 ,B 34 ,B 66 ,B 98 are then radiated from the array probe 10. Signals of reflected waves of these ultrasonic beams are inputted to input terminals of the adder/switching circuit 29, which input terminals are surrounded by squares. Subsequent processing is the same as the processing of the signals of reflected waves of the ultrasonic beams B 1 -B 97 . As a result, ultrasonic images of next points of the specimen, said points being shifted by one pitch from the above four points, are displayed.
In this manner, the electronic scanning with ultrasonic beams advances successively in the direction indicated by the arrows in FIG. 10. Upon completion of the scanning with up to the ultrasonic beams B 8 ,B 40 , B 72 ,B 104 , the individual switches S of the adder/switching circuit 29 are all changed over to the opposite sides in accordance with commands from the microprocessor 26. As a consequence, the respective array elements of the intermediate sections K 12' ,K 23' ,K 34' shown in FIG. 11(a) are caused to belong to the blocks K 1' ,K 2' ,K 3' , respectively. The electronic scanning is continuously performed even during this switching.
When the electronic scanning proceeds to the ultrasonic beams B 26 ,B 58 ,B 90 (the scanning in the block K 4' has been completed with the ultrasonic beam B 121 in the previous stage), signals of reflected waves of these ultrasonic beams are inputted to input terminals of the adder/switching circuit 29, said input terminals being surrounded by squares, as shown in FIG. 11(c). In this case, the 33rd, 65th and 97th input terminals of the intermediate sections K 12' ,K 23' ,K 34' again take part in the input of reflected wave signals. Thereafter, similar processing is performed. The electronic scanning which is continued in the above manner is completed upon radiation of the ultrasonic beams B 32 ,B 64 , B 96 . Here, these reflected wave signals are inputted to input terminals of the adder/switching circuit 29, said input terminals being surrounded by squares, as shown in FIG. 15(d). Thereafter, similar processing to the aforementioned processing is performed. As a result, the electronic scanning of one line is completed.
In this embodiment, the array elements are divided into the four blocks by the shift register. In each of the blocks, eight consecutive array elements are vibrated while successively shifting the vibration of the array elements one element by element, whereby ultrasonic beams are moved. On the other hand, the input terminals of the adder/switching circuit, to which signals of reflected waves of the ultrasonic beams are inputted, are divided into the four blocks and three intermediate sections. The switches are connected to the input terminals in the intermediate sections, so that the individual input terminals of these intermediate sections can be selectively connected to both of the associated adjacent blocks. It is therefore possible to shorten the speed of electronic scanning to one fourth compared to a conventional flaw detector having the same number of array elements and thus to substantially shorten the inspection time without omission of ultrasonic beams at the boundaries of the four blocks of the array elements. Furthermore, in spite of the division of the array elements into the four blocks, no modification is needed to the matrix circuit which is adapted to apply predetermined delays to the respective pulsers. Although twenty-four switches are provided in the adder/switching circuit, all the switches are changed over at the same time so that the load to the microprocessor is extremely small.
It is to be noted that the number of divisions of the array probe (the number of simultaneous beams), the total number of array elements and the number of array elements taking part in the formation of an ultrasonic beam (the number of simultaneously vibrated elements) can be chosen as desired. These numbers and various numbers based thereon are shown in FIG. 12.
Another embodiment of the present invention will next be described. This embodiment is different from the preceding embodiment only in the constructions of the adder/switching circuit 29 and matrix circuits 19K 1 -19K 4 and the procedure by the microprocessor 26 which controls the adder/switching circuit and matrix circuits. These adder/switching circuit, matrix circuits and microprocessor are shown in FIG. 9. The remaining elements are the same as the corresponding elements in the preceding embodiment. A description will therefore be made of an adder circuit 29' and matrix circuits 19K 1' -19K 4' in the present embodiment, which correspond to the adder/switching circuit 29 and matrix circuits 19K 1 -19K 4 in the preceding embodiment.
FIG. 13 is a circuit diagram of the adder circuit 29'. In the drawing, numerals 1-128 indicate the numbers of input terminals of the adder circuit 29' and symbols W 11' -W 48' designate adders. The adder circuit 29' is different from the adder/switching circuit 29 in the preceding embodiment in that the adders W 11 -W 48 in the preceding embodiment individually have five input terminals and the adjacent input terminals of each two adjacent adders are changed over by the switch S while the adders W 11' -W 48' in this embodiment individually have four input terminals and have neither switches S nor terminals to be changed over by such switches. Accordingly, signals from the transmit/receive circuit 27 are simply and successively inputted to the individual terminals in the four blocks.
FIGS. 14(a), 14(b), 14(c) and 14(d) are circuit diagrams of the matrix circuits 19K 1' -19K 4' . The matrix circuit 19K 1' comprises two matrix switches 19K 11' ,19K 12' , whereas the matrix circuit 19K 2' comprises two matrix switches 19K 21' ,19K 22' . Further, the matrix circuit 19K 3' comprises two matrix switches 19K 31' ,19K 32' , whereas the matrix circuit 19K 4' comprises two matrix switches 19K 41' ,19K 42' . Output terminals of the adders W 11' -W 18' shown in FIG. 13 are connected to the matrix switch 19K 11' , and output terminals of the adders W 21' -W 28' are connected both the matrix switch 19K 12' , and the matrix switch 19K 21' . Furthermore, output terminals of the adders W 31' -W 38' are connected to both the matrix switch 19K 22' and the matrix switch 19K 31' , and output terminals of the adders W 41' -W 48' are connected to both the matrix switch 19K 32' and the matrix switch 19K 41' . The matrix switch 19K 42' is a dummy switch which will not be used. Output lines of the matrix circuits 19K 1' -19K 4' are common to the associated two matrix switches and are connected to waveform adders 20K 1 -20K 4 .
Next, the operation of this embodiment will be described. In FIG. 14(a), the 1st-8th terminals of the adders W 11' -W 18' , the 33rd-40th terminals of the adders W 21' -W 28' , the 65th-72nd terminals of the adders W 31' -W 38' and the 97th-104th terminals of the adders W 31' -W 38' , all the adders being shown in FIG. 13, have been inputted with signals, respectively. In this state, the matrix switches at the crossing points indicated by circles out of the individual matrix switches are closed. Signals appeared at the individual terminals are inputted to the waveform addition circuits 20K 1 -20K 4 , respectively. Namely, signals of reflected waves of the ultrasonic beams B 1 ,B 33 ,B 65 ,B 97 depicted in FIG. 10 are obtained at the respective waveform addition circuits 20K 1 -20K 4 .
When the transmit-receive circuit 27 is switched and shifted by the shift register 28 subsequent to the above state, the state of signal inputs to the respective matrix circuits 19K 1' -19K 4' becomes as shown in FIG. 14(b). At this time, the state of closure of each individual matrix switch is as indicated by a circle. As a result, data on reflected waves of the next ultrasonic beams in the respective blocks are obtained at the waveform addition circuits 20K 1 -20K 4 , respectively.
In the manner described above, the individual matrix switches 19K 11' ,19K 21' ,19K 31' ,19K 41' are successively changed over to obtain individual reflected wave data. When the first array elements 10 33 ,10 65 ,10 97 in the boundary sections K 12 ,K 23 ,K 34 depicted in FIG. 10 become ready for use again, in other words, the 33rd, 65th and 97th terminals shown in FIG. 13 are brought into a signal-inputted state again, one switches of the matrix switches 19K 12' ,19K 22' ,19K 32' ,19K 42' of the individual matrix circuits 19K 1' -19K 4' , said one switches corresponding respectively to the above terminals, are brought into a closed state as indicated by circles in FIG. 14(c). Thereafter, the vibration of the array elements in the respective boundary sections K 12 -K 34 is shifted one element by one element and at the same time, the closure of crossing points of one matrix switches 19K 11' -19K 41' is shifted one crossing point by one crossing point toward the other matrix switches 19K 11' -19K 41' . In this manner, the formation of ultrasonic beams by the use of the array elements of the boundary sections K 12 -K 34 is shifted successively. Upon formation of the last ultrasonic beams, the state of closure of the respective matrix switches is as indicated by circles in FIG. 14(d). Namely, in each of one matrix switches 19K 11' ,19K 21' ,19K 31' , 19 41' , only one crossing point is in a closed state. In each of the other matrix switches 19K 12' ,19K 22' ,19K 32' .19K 42' , seven closed states are formed.
Omission of ultrasonic beams can be prevented by forming two matrix switched in the matrix circuit as described above, thereby bringing about the same effects as the preceding embodiment. Moreover, the construction of the adder circuit 29' can be simplified in this embodiment. Owing to this, the adders W 11' -W 18' , W 21' -W 28' , W 31' -W 38' , W 41' -W 48' can be fabricated as discrete integrated circuits so that the fabrication can be facilitated.
In the description of each of the above embodiments, array elements were arranged, as an array probe, in a straight line by way of example. The array elements are not limited to such arrangements. They may be arranged in plural lines. In such case, each line can be provided with a control unit. As an alternative, the circuit constructions of the shift register and the circuit constructions of the adder/switching circuit and the subsequent circuits can be modified. When a specimen has a curved surface or where the points of inspection targets are on a curved surface, array elements may be arranged in a pattern extending along the curved surface rather than in a straight line. Where the curved surface is a simple curved surface, the array elements may be arranged in a straight line provided that the setting of delay times is modified by a microprocessor to conform with the curved surface. Electronic switching elements are of course used as the switches in the adder/switching circuit. It is necessary to perform their change-over after an input to the last input terminal of the input terminals of each intermediate section is completed but before an input next takes place to the first input terminal. In the above embodiments, adders were used in the adder/switching circuits. They were employed in view of impedance matching. Where it is unnecessary to take impedance matching into account, the simple connection shown in FIG. 7 can be used.
In the above description, the sampling pitch of ultrasonic scanning was set equal to the pitch of arrangement of the array elements to facilitate the understanding. In order to make the sampling pitch still finer, there have however been adopted a means for selecting array elements, which take part in the formation of a beam, in varied combinations such that the even-numbered array elements are first selected and the odd-numbered array elements are then selected; and a means for varying the number of array elements which take part upon transmission of an ultrasonic beam and reception or selecting such array elements in different combinations. These means have been well known in the art. It is apparent that these means can also be incorporated in detectors according to the present invention.
As has been described above, the array elements are divided into plural blocks, and the input terminals of the input/output unit are also divided into blocks corresponding to the first-mentioned blocks and intermediate sections corresponding to the boundaries of the first-mentioned blocks. The individual input terminals in each intermediate section can be caused to belong to both of the associated adjacent blocks by a switching means. The present invention can therefore substantially shorten the time of electronic scanning making use of ultrasonic beams and accordingly, to significantly improve the inspection speed. | The present invention is directed to an ultrasonic flaw detector for inspecting the surface condition of a specimen or the existence or non-existence of one or more internal defects in the specimen by scanning the specimen with ultrasonic waves and analyzing waves reflected by the specimen. The ultrasonic flaw detector includes a number of array elements arranged in a line. The ultrasonic beam scanning of a specimen is performed by vibrating plural ones of the array elements to form a single ultrasonic beam and shifting vibration of the array elements one by one. Array elements are divided into plural blocks by a block selector. Ultrasonic scanning is simultaneously conducted in the respective blocks. Omission of ultrasonic scanning between each two adjacent blocks is avoided by setting the blocks to overlap at adjacent sections and causing, with a switch, the array elements in the overlapped sections to belong to one of the blocks at a certain time point to take part in ultrasonic scanning and to the other block at another time point to take part in ultrasonic scanning. Owing to this construction, ultrasonic scanning can be performed quickly. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Application No. 2002-41967, filed Jul. 18, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a washing machine and method of controlling the same, and more particularly, to a washing machine and method of controlling the same, which dissolves a detergent using a detergent dispenser and supplies the dissolved liquid detergent to a washing tub.
[0004] 2. Description of the Related Art
[0005] In general, washing machines are divided into drum-type washing machines and washing machines using pulsators. The drum-type washing machine washes laundry by a displacement of the laundry caused by a rotation of a rotating tub, while the washing machine using the pulsator washes the laundry by water currents generated by a rotation of the pulsator mounted on a bottom surface of a tub. Since the drum-type washing machine washes the laundry by the displacement caused by the rotation of the rotating tub, a small quantity of washing water to soak the laundry is used. This is one of advantages of the drum-type washing machine. Since the washing machine using the pulsator has to generate strong water currents by rotating the pulsator after supplying sufficient washing water for the laundry to be completely submerged under the washing water, a large quantity of washing water is needed in comparison with the drum-type washing machine.
[0006] [0006]FIG. 1 is a perspective view illustrating a construction of a conventional drum-type washing machine. As shown in FIG. 1, a fixed tub 102 is mounted in a body 100 to contain washing water therein, and a rotating tub 108 is mounted in the fixed tub 102 to perform washing, rinsing and spin-drying processes by a rotation of a motor 110 . A number of holes are formed in a surface of the rotating tub 108 , so the washing water can flow from the rotating tub 108 to the fixed tub 102 and vice versa through the holes and washing the water centrifugally separated from the laundry flows into a space between the rotating tub 108 and the fixed tub 102 during the spin-drying process. A washing machine provided with a drying heater 114 drying the laundry can further perform a drying process in addition to the washing, rinsing, and spin-drying processes of a general drum-type washing machine. In FIG. 1, hot and cold washing water passed through water supply valves 118 and 120 are first supplied by water pipes 124 to a detergent dispenser 122 and then supplied to the fixed tub 102 through a water supply pipe 126 along with a detergent.
[0007] [0007]FIG. 2 is a flowchart showing a method of controlling the conventional drum-type washing machine. As shown in FIG. 2, a washing course is set by a user at operation S 202 , and washing water of a quantity corresponding to the set washing course is supplied to the fixed tub 102 through the detergent dispenser 122 at operation S 204 . A detergent contained in the detergent dispenser 122 is dissolved by the washing water and supplied to the fixed tub 102 along with the washing water. After the washing water of the quantity corresponding to the set washing course has been supplied, a washing process is performed by the rotation of the rotating tub 108 at operation S 206 . After the washing process has been completed, a rinsing process is performed by repeating the supplying of a preset quantity of the washing water and spin-drying at operation S 208 . After the rinsing process has been completed, a spin-drying process is performed by the rotation of the rotating tub 108 at operation S 210 . After the spin-drying process has been completed, a drying process that removes the washing water soaked in the laundry in the rotating tub 108 is performed by operating the drying heater 114 at operation S 212 .
[0008] In the conventional drum-type washing machine, the washing water supplied to the detergent dispenser 122 is supplied to the fixed tub 102 through the detergent dispenser 122 . In a course of supplying the washing water, the detergent contained in the detergent dispenser 122 is dissolved and supplied to the fixed tub 102 along with the washing water. In this case, since the washing water passes through the detergent dispenser 122 at a high speed, the detergent is supplied to the fixed tub 102 along with the washing water with the detergent insufficiently dissolved. The detergent needs to be sufficiently dissolved to prevent stains generated by an undissolved detergent from remaining on the laundry, and to improve a washing efficiency. Accordingly, after the supplying of the washing water and the detergent is completed, the detergent needs to be sufficiently diluted with the washing water by a forward rotation and a reverse rotation of the rotating tub 108 in the drum-type washing machine.
[0009] To sufficiently dilute the undissolved detergent in the rotating tub 108 with the washing water, a larger quantity of the washing water than a normal quantity of the washing water is needed. Although the drum-type washing machine is designed to wash the laundry with a small quantity of the washing water to soak the laundry, the larger quantity of the washing water than the normal quantity of the washing water has to be supplied to sufficiently dissolve the detergent because of the detergent sinking to a bottom of the fixed tub 102 which has to be dissolved using water currents generated by the forward rotation and the reverse rotation of the rotating tub 108 . Thus, the quantity of the washing water is unavoidably increased to be equal to or greater than a maximum quantity of the washing water to soak the laundry in the conventional drum-type washing machine, so an increase in the quantity of the washing water causes an excessive consumption of the washing water, an increase in an amount of load on a rotating tub driving motor, and increases a time and energy required to heat the washing water in the drum-type washing machine in which a boiling process is carried out, thus increasing a power consumption and a total operating time thereof.
SUMMARY OF THE INVENTION
[0010] Accordingly, an aspect of the present invention is to provide a washing machine and method of controlling the washing machine, in which a large quantity of washing water is directly supplied to a rotating tub, a small quantity of the washing water to dissolve detergent is supplied to a detergent dispenser separately from the directly supplied washing water to allow the detergent to be dissolved at a high concentration in the detergent dispenser, and the dissolved high concentration liquid detergent is supplied to the rotating tub after the directly supplied washing water has been supplied to the rotating tub so that the laundry is sufficiently soaked in the washing water.
[0011] Additional 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.
[0012] To accomplish the above and/or other aspects, a washing machine having a fixed tub and a rotating tub, comprising a detergent dispenser containing a detergent, receiving a preset quantity of washing water and allowing the detergent to be dissolved therein, thus forming a liquid detergent; and a control unit controlling the liquid detergent contained in the detergent dispenser to be sprayed on laundry in the rotating tub after a completion of direct supplying of a large amount of the washing water to the fixed tub.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] These and other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:
[0014] [0014]FIG. 1 is a perspective view illustrating a construction of a conventional drum-type washing machine;
[0015] [0015]FIG. 2 is a flowchart illustrating a conventional method of controlling the conventional drum-type washing machine;
[0016] [0016]FIG. 3 is a perspective view illustrating a construction of a drum-type washing machine in accordance with an embodiment of the present invention;
[0017] [0017]FIG. 4 is a block diagram illustrating the drum-type washing machine of FIG. 3; and
[0018] [0018]FIG. 5 is a flowchart illustrating a method of controlling the drum-type washing machine of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Reference will now made in detail to the present preferred 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.
[0020] Referring to FIGS. 3 to 5 , a washing machine and control method thereof is described. FIG. 3 is a perspective view illustrating a construction of a drum-type washing machine in accordance with an embodiment of the present invention. As shown in FIG. 3, a fixed tub 302 is mounted in a body 300 to contain washing water, and a rotating tub 308 is mounted in the fixed tub 302 to perform washing, rinsing, and spin-drying processes while being rotated by a driving force of a motor 310 . A number of holes are formed in the rotating tub 308 , so that the washing water can flow from the rotating tub 308 to the fixed tub 302 and vice versa and the washing water centrifugally separated from laundry flows into a space between the rotating tub 308 and the fixed tub 302 during a spin-drying process. The washing machine may be provided with a drying heater 314 drying the laundry. The drying heater performs a drying process in addition to the washing, rinsing, and spin-drying processes of a drum-type washing machine. Further, the drum-type washing machine provided with a washing water heating unit 330 can provide a same effect as that of directly boiling the laundry by heating the washing water to a high temperature. A large part of the washing water supplied through a first water supply valve 318 and a second water supply valve 320 is directly supplied to the fixed tub 302 through water supply pipes 328 . A remaining small part of the washing water supplied through the first and second water supply valves 318 and 320 is supplied to a detergent dispenser 322 through the water supply pipes 324 and used to dissolve the detergent contained in the detergent dispenser 322 . The liquid detergent dissolved by the remaining small part of the washing water in the detergent dispenser is supplied to the fixed tub 302 by a water pipe 328 that is connected between the detergent dispenser 322 and the fixed tub 302 after a completion of the direct supplying of the large part of the washing water.
[0021] In the washing machine, the small part of the washing water containing the detergent is sprayed on the laundry in the rotating tub 308 , so that the large part of the washing water is uniformly supplied to the laundry, as a whole. After the direct supplying of the large part of the washing water is completed, the liquid detergent, which is supplied from the detergent dispenser 322 to the fixed tub 302 , is sprayed on the laundry, so that the liquid detergent is uniformly supplied to the whole laundry.
[0022] In the washing machine a sum of a quantity of the washing water directly supplied to the fixed tub 302 and a quantity of the washing water supplied to the detergent dispenser 322 is less than or equal to a quantity of the washing water corresponding to a washing course set by a user. For example, when the quantity of the washing water corresponding to the set washing course is 10 liters, the sum of the quantity of the washing water supplied to the fixed tub 302 and the quantity of the washing water supplied to the detergent dispenser 322 is less than or equal to 10 liters. This restriction prevents a total quantity of the washing water from increasing as a result of an addition of the quantity of the washing water to dissolve the detergent to the quantity of washing water corresponding to the set washing course. Accordingly, an increase in the total quantity of the washing water is suppressible.
[0023] [0023]FIG. 3 shows the construction of a drum-type washing machine of an embodiment of the present invention. However, it is understood by those of skill in the art that the above-described construction can be applied to general washing machines using pulsators.
[0024] [0024]FIG. 4 is a block diagram illustrating the drum-type washing machine FIG. 3. As shown in FIG. 4, a control unit 402 controls an overall operation of the washing machine, such as washing, rinsing, spin-drying, and drying processes. An input unit 406 sets washing conditions desired by a user, or selectively commands only processes needed by a user. The washing conditions and commands set by the input unit 406 are transmitted to the control unit 402 . A water level sensor 404 is used to detect a quantity of washing water supplied, and detects the quantity of the washing water supplied to the fixed tub 302 and provides information about the detected quantity of the washing water to the control unit 402 .
[0025] A drive unit 410 drives the motor 310 , a drain pump 316 , the drying heater 314 , a display unit 412 , the first and second water supply valves 318 and 320 and the like. The motor 310 periodically rotates the rotating tub 308 in forward and reverse directions at a high speed during washing or rinsing processes, and rotates the rotating tub 308 in a forward direction at the high speed during a spin-drying process. The drain pump 316 discharges the washing water stagnating on a bottom surface of the fixed tub 302 . The drying heater 314 dries the laundry by circulating heated air through the fixed tub 302 . The display unit 412 visually displays an operating state of the drum-type washing machine. The first and second water supply valves 318 and 320 control the supplying of hot and cold water, respectively.
[0026] Referring to FIG. 5, a method of controlling the drum-type washing machine FIG. 3 is described. FIG. 5 is a flowchart illustrating the drum-type washing machine control method. As shown in FIG. 5, if a washing course is set by a user at operation S 502 , a preset small quantity of the washing water is supplied to the detergent dispenser 322 through the first and second water supply valves 318 and 320 , and the detergent contained in the detergent dispenser 322 is dissolved at operation S 504 a. Simultaneously, the washing water of a quantity obtained by subtracting the preset small quantity of the washing water supplied to the detergent dispenser 322 from a total quantity of the washing water corresponding to the washing course set by the user is directly supplied to the fixed tub 302 through the water supply pipes 328 and sprayed on the laundry at operation S 504 b. Accordingly, the laundry can be uniformly soaked by spraying a large part of washing water thereon.
[0027] After the supplying of the large part of the washing water to the fixed tub 302 is completed, a high concentration liquid detergent dissolved by the washing water in the detergent dispenser 322 is sprayed on the sufficiently soaked laundry on which the large part of the washing water has been sprayed at operation S 506 . Since the sufficiently dissolved liquid detergent is sprayed on the laundry after the large part of the washing water has been supplied to the laundry and then the laundry has been sufficiently soaked, a generation of stains on the laundry, which may be generated by the detergent when an insufficiently dissolved detergent is supplied to the laundry that is insufficiently soaked, is preventable. Further, since the detergent can be dissolved by the small quantity of the washing water, the total quantity of the washing water is decreased in comparison with a case where the total quantity of the washing water and the detergent have been supplied together and then the detergent is dissolved in the fixed tub 302 . Therefore, a quantity of used washing water can be decreased. Further, since the previously dissolved detergent is supplied to the fixed tub 302 , the undissolved detergent does not remain, so the washing performance of the washing machine is maximized.
[0028] After the supplying of the washing water and the liquid detergent is completed, the washing process is performed by rotating the rotating tub 308 at operation S 508 . Thereafter, the rinsing process is performed by repeating the supplying of the washing water and spin-drying at operation S 510 . Thereafter, the spin-drying process is performed by rotating the rotating tub 308 at operation S 512 . After the spin-drying process is completed, the drying process that removes the water soaked in the laundry in the rotating tub 308 is performed by operating the drying heater 314 at operation S 514 .
[0029] The drum-type washing machine is constructed so that a large part of washing water is directly supplied to the fixed and rotating tubs without passing through a detergent dispenser, and a small part of the washing water to dissolve a detergent is supplied to the detergent dispenser separately from the large part of the washing water to dissolve the detergent at a high concentration in the detergent dispenser. With this construction, stains, which may be generated by an undissolved detergent remaining on laundry, are preventable and a washing performance of the drum-type washing machine can be improved by sufficiently spraying the high concentration liquid detergent on the laundry after the large part of the washing water is supplied to the fixed tub. Further, since the previously dissolved detergent is supplied, a total quantity of the washing water can be greatly decreased in comparison with a case where the washing water and the detergent are supplied together, and a power consumption and a total time required to wash the laundry are decreased by a reduction in an amount of load on the rotating tub driving motor. Further, since the total quantity of the washing water is decreased, a time required to heat the washing water is greatly decreased in washing machines that perform a boiling process by heating the washing water.
[0030] Although a few preferred 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 this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. | A washing machine and method of controlling the washing machine. The washing machine includes a fixed tub, a rotating tub, a detergent dispenser and a control unit. The detergent dispenser contains a detergent, receives a preset quantity of washing water and allows the detergent to be dissolved therein, thus forming a liquid detergent. The control unit controls the liquid detergent contained in the detergent dispenser to be sprayed on laundry in the rotating tub after a completion of direct supplying of a large amount of the washing water to one or more of the fixed tub and the rotating tub. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser. No. 13/904,587, filed on May 29, 2013, which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/652,549 filed 29 May 2012, which application is herein specifically incorporated by reference in its entirety.
SEQUENCE LISTING
[0002] This application incorporates by reference the sequence listing submitted in computer readable form as file 8150A-2_ST25.txt created on Aug. 6, 2013 (206,310 bytes).
FIELD
[0003] The invention relates to a cell or cells expressing a recombinant stress-response lectin for the improved production of a multi-subunit protein. Specifically, the invention provides a mammalian cell and cell-line derived therefrom containing a gene encoding EDEM2, and which yields antibody at a high titer.
BACKGROUND
[0004] The manufacture of therapeutically active proteins requires proper folding and processing prior to secretion. Proper folding is particularly relevant for proteins, such as antibodies, which consist of multiple subunits that must be properly assembled before secretion. Eukaryotic cells have adapted a system that ensures the proper folding of proteins and the removal of misfolded proteins from the secretory pathway. This system is called the unfolded protein response (UPR) pathway, and it is triggered by the accumulation of misfolded proteins in the endoplasmic reticulum (ER).
[0005] An early event of the UPR is the activation of the transcription factor Xbp1, which in turn activates the transcription of endoplasmic reticulum degradation-enhancing alpha-mannosidase-like protein 2 (EDEM2), a member of the endoplasmic reticulum associated degradation (ERAD) pathway. EDEM2 facilitates the removal of misfolded proteins. The ERAD pathway comprises five steps: (1) chaperone-mediated recognition of malformed proteins, (2) targeting of malformed proteins to the retrotranslocation machinery or E3-ligases, which involves EDEM2, (3) initiation of retrotranslocation; (4) ubiquitylation and further retrotranslocation; and (5) proteosome targeting and degradation.
[0006] Antibodies are multi-subunit proteins comprising two heavy chains and two light chains, which must be properly folded and associated to form a functional heterotetramer. Any improvement in the efficient and accurate processing of the heavy and light chains to improve the yield or titer of functional antibody heterotetramers is desired.
SUMMARY
[0007] Applicants made the surprising discovery that the ectopic expression of EDEM2 in a protein-manufacturing cell line increases the average output of protein per cell, increases the titer of protein secreted into the media, and increases the integrated cell density of production cell lines.
[0008] Thus, in one aspect, the invention provides a cell containing (a) a recombinant polynucleotide that encodes a stress-induced mannose-binding lectin and (b) a polynucleotide that encodes a multi-subunit protein. In some embodiments, the stress-induced mannose-binding lectin is an EDEM2 protein, non-limiting examples of which are provided in Table 1, and the multi-subunit protein is an antibody. In other embodiments, the cell also contains a polynucleotide that encodes the active spliced form of XBP1, non-limiting examples of which are provided in Table 2. In one embodiment, the cell is a mammalian cell, such as a CHO cell used in the manufacture of biopharmaceuticals.
[0009] In another aspect, the invention provides a cell line derived from the cell described in the previous aspect. By “derived from”, what is meant is a population of cells clonally descended from an individual cell and having some select qualities, such as the ability to produce active protein at a given titer, or the ability to proliferate to a particular density. In some embodiments, the cell line, which is derived from a cell harboring the recombinant polynucleotide encoding a stress-induced mannose-binding lectin and a polynucleotide encoding a multi-subunit protein, is capable of producing the multi-subunit protein at a titer of at least 3 grams per liter of media (g/L), at least 5 g/L, or at least 8 g/L. In some embodiments, the cell line can attain an integrated cell density (ICD) that is at least 30% greater, at least 50% greater, at least 60% greater, or at least 90% greater than the integrated cell density attainable by a cell line derived from what is essentially the same cell but without the recombinant polynucleotide encoding the stress-induced mannose-binding lectin.
[0010] In another aspect, the invention provides an isolated or recombinant polynucleotide comprising a nucleic acid sequence encoding an EDEM2 protein, which is operably linked (cis) to a constitutive and ubiquitously expressed mammalian promoter, such as the ubiquitin C promoter. In some embodiments, the EDEM2 protein has the amino acid of SEQ ID NO: 8, or an amino acid sequence that is at least 92% identical to any one of SEQ ID NO: 1-7. In some embodiments, the polynucleotide comprises a nucleic acid sequence of SEQ ID NO: 16. In one particular embodiment, the polynucleotide consists of a nucleic acid sequence of SEQ ID NO: 14; and in another particular embodiment, SEQ ID NO: 15.
[0011] In another aspect, the invention provides an isolated or recombinant polynucleotide comprising a nucleic acid sequence encoding an XBP1 protein, which is operably linked to (in cis) a constitutive and ubiquitously expressed mammalian promoter, such as the ubiquitin C promoter. In some embodiments, the XBP1 protein has the amino acid of SEQ ID NO: 13, or an amino acid sequence that is at least 86% identical to any one of SEQ ID NO: 9-12. In some embodiments, the polynucleotide comprises a nucleic acid sequence of SEQ ID NO: 18. In one particular embodiment, the polynucleotide consists of a nucleic acid sequence of SEQ ID NO: 17.
[0012] In another aspect, the invention provides a cell that contains an EDEM2-encoding polynucleotide, as described in the prior aspect, and a polynucleotide that encodes a multi-subunit protein, such as an antibody. In some embodiments, the cell also contains an XBP1-encoding polynucleotide, as described in the preceding aspect. In one embodiment, the multi-subunit protein is an antibody, and the heavy chain of the antibody comprises an amino acid sequence of SEQ ID NO: 43 and SEQ ID NO: 44, and the light chain of the antibody comprises an amino acid sequence of SEQ ID NO: 45 and SEQ ID NO: 46. In this and several embodiments, each polypeptide subunit of the multi-subunit protein is encoded by a separate polynucleotide. Thus, for example, a polynucleotide encoding an antibody may include a polynucleotide encoding a heavy chain and a polynucleotide encoding a light chain, hence two subunits. In some embodiments, the cell is a chinese hamster ovary (CHO) cell.
[0013] In one embodiment, the encoded multi-subunit protein is an anti-GDF8 antibody having a heavy chain variable region amino acid sequence of SEQ ID NO: 20 and a light chain variable region amino acid sequence of SEQ ID NO: 22. In one embodiment, the anti-GDF8 antibody comprises a heavy chain having an amino acid sequence of SEQ ID NO: 19 and a light chain having an amino acid sequence of SEQ ID NO: 21. In one embodiment, the polynucleotide that encodes the heavy chain of the anti-GDF8 antibody comprises a nucleic acid sequence of SEQ ID NO: 23; and the polynucleotide that encodes the light chain of the anti-GDF8 antibody comprises a nucleic acid sequence of SEQ ID NO: 25. In one embodiment, the polynucleotide that encodes the heavy chain of the anti-GDF8 antibody consists of a nucleic acid sequence of SEQ ID NO: 24; and the polynucleotide that encodes the light chain of the anti-GDF8 antibody consists of a nucleic acid sequence of SEQ ID NO: 25.
[0014] In another embodiment, the encoded multi-subunit protein is an anti-ANG2 antibody having a heavy chain variable region amino acid sequence of SEQ ID NO: 28 and a light chain variable region amino acid sequence of SEQ ID NO: 30. In one embodiment, the anti-ANG2 antibody comprises a heavy chain having an amino acid sequence of SEQ ID NO: 27 and a light chain having an amino acid sequence of SEQ ID NO: 29. In one embodiment, the polynucleotide that encodes the heavy chain of the anti-ANG2 antibody comprises a nucleic acid sequence of SEQ ID NO: 31; and the polynucleotide that encodes the light chain of the anti-ANG2 antibody comprises a nucleic acid sequence of SEQ ID NO: 33. In one embodiment, the polynucleotide that encodes the heavy chain of the anti-ANG2 antibody consists of a nucleic acid sequence of SEQ ID NO: 32; and the polynucleotide that encodes the light chain of the anti-ANG2 antibody consists of a nucleic acid sequence of SEQ ID NO: 34.
[0015] In another embodiment, the encoded multi-subunit protein is an anti-ANGPTL4 antibody having a heavy chain variable region amino acid sequence of SEQ ID NO: 36 and a light chain variable region amino acid sequence of SEQ ID NO: 38. In one embodiment, the anti-ANGPTL4 antibody comprises a heavy chain having an amino acid sequence of SEQ ID NO: 35 and a light chain having an amino acid sequence of SEQ ID NO: 37. In one embodiment, the polynucleotide that encodes the heavy chain of the anti-ANGPTL4 antibody comprises a nucleic acid sequence of SEQ ID NO: 39; and the polynucleotide that encodes the light chain of the anti-ANGPTL4 antibody comprises a nucleic acid sequence of SEQ ID NO: 41. In one embodiment, the polynucleotide that encodes the heavy chain of the anti-ANGPTL4 antibody consists of a nucleic acid sequence of SEQ ID NO: 40; and the polynucleotide that encodes the light chain of the anti-ANGPTL4 antibody consists of a nucleic acid sequence of SEQ ID NO: 42.
[0016] In another aspect, the invention provides a method of manufacturing a multi-subunit protein, by culturing a cell of the previous aspect in a medium, wherein the multi-subunit protein is synthesized in the cell and subsequently secreted into the medium. In some embodiments, the multi-subunit protein is an antibody, such as for example anti-GDF8, anti-ANG2, anti-ANGPTL4, or an antibody having a heavy chain sequence of SEQ ID NO: 43 and 44, and a light chain sequence of SEQ ID NO: 45 and 46. In some embodiments, the multi-subunit protein attains a titer of at least 3 g/L, at least 5 g/L, at least 6 g/L, or at least 8 g/L. In some embodiments, the cell proliferates in the medium and establishes an integrated cell density of about ≧5×10 7 cell-day/mL, about ≧1×10 8 cell-day/mL, or about ≧1.5×10 8 cell-day/mL.
[0017] In another aspect, the invention provides a multi-subunit protein, which is manufactured according to the method described in the preceding aspect. In one embodiment, the manufactured protein is an antibody. In some embodiments, the antibody consists of a heavy chain, which comprises an amino acid sequence of SEQ ID NO: 43 and SEQ ID NO: 44, and a light chain, which comprises an amino acid sequence of SEQ ID NO: 45 and SEQ ID NO: 46. In one specific embodiment, the manufactured multi-subunit protein is an anti-GDF8 antibody having a heavy chain variable region amino acid sequence of SEQ ID NO: 20 and a light chain variable region amino acid sequence of SEQ ID NO: 22. In another specific embodiment, the manufactured multi-subunit protein is an anti-ANG2 antibody having a heavy chain variable region amino acid sequence of SEQ ID NO: 28 and a light chain variable region amino acid sequence of SEQ ID NO: 30. In yet another specific embodiment, the manufactured multi-subunit protein is an anti-ANGPTL4 antibody having a heavy chain variable region amino acid sequence of SEQ ID NO: 36 and a light chain variable region amino acid sequence of SEQ ID NO: 38.
DESCRIPTION
[0018] Before the present invention is described, it is to be understood that this invention is not limited to particular methods and experimental conditions described, as such methods and conditions may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.
[0019] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. As used herein, the term “about”, when used in reference to a particular recited numerical value or range of values, means that the value may vary from the recited value by no more than 1%. For example, as used herein, the expression “about 100” includes 99 and 101 and all values in between (e.g., 99.1, 99.2, 99.3, 99.4, etc.).
[0020] Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference in their entirety.
[0021] As used herein, the term “recombinant polynucleotide”, which is used interchangeably with “isolated polynucleotide”, means a nucleic acid polymer such as a ribonucleic acid or a deoxyribonucleic acid, either single stranded or double stranded, originating by genetic engineering manipulations. A recombinant polynucleotide may be a circular plasmid or a linear construct existing in vitro or within a cell as an episome. A recombinant polynucleotide may be a construct that is integrated within a larger polynucleotide molecule or supermolecular structure, such as a linear or circular chromosome. The larger polynucleotide molecule or supermolecular structure may be within a cell or within the nucleus of a cell. Thus, a recombinant polynucleotide may be integrated within a chromosome of a cell.
[0022] As used herein, the term “stress-induced mannose-binding lectin” refers to a mannose-binding protein, which means a protein that binds or is capable of binding mannose, derivatives of mannose, such as mannose-6-phosphate, or a glycoprotein that expresses mannose or a mannose derivative in its glycocalyx; and whose activity is upregulated during stress. Cellular stress includes inter alia starvation, DNA damage, hypoxia, poisoning, shear stress and other mechanical stresses, tumor stress, and the accumulation of misfolded proteins in the endoplasmic reticulum. Exemplary stress-induced mannose-binding lectins include the EDEM proteins EDEM1, EDEM2 and EDEM3, Yos 9, OS9, and XTP3-B (see Vembar and Brodsky, Nat. Rev. Mol. Cell. Biol. 9(12): 944-957, 2008, and references cited therein).
[0023] As used herein, the term “EDEM2” means any ortholog, homolog, or conservatively substituted variant of endoplasmic reticulum degradation-enhancing alpha-mannosidase-like protein. EDEM2 proteins are generally known in the art to be involved in endoplasmic reticulum-associated degradation (ERAD), being up-regulated by Xbp-1 and facilitating the extraction of misfolded glycoproteins from the calnexin cycle for removal. (See Mast et al., Glycobiology 15(4): 421-436, 2004; Olivari and Molinari, FEBS Lett. 581: 3658-3664, 2007; Olivari et al., J. Biol. Chem. 280(4): 2424-2428, 2005; and Vembar and Brodsky 2008, which are herein incorporated by reference.) Exemplary EDEM2 sequences are depicted in Table 1, which is cross-referenced to the Sequence Listing.
[0000]
TABLE 1
Animal
SEQ ID NO:
% id human
% id mouse
% id hamster
Mouse
1
93
100
96
Rat
2
94
98
96
Hamster
3
93
96
100
Human
4
100
93
93
Chimpanzee
5
99
94
93
Orangutan
6
97
92
92
Zebra fish
7
69
70
69
Consensus
8
100
100
100
[0024] As used herein, the term “Xbp1”, also known as XBP1 or X-box binding protein 1, means any ortholog, homolog, or conservatively substituted variant of Xbp1. Xbp1 is a transcription factor and functional element of the UPR. ER stress activates both (1) the transcription factor ATF6, which in turn upregulates the transcription of Xbp1 mRNA, and (2) the ER membrane protein IRE1, which mediates the splicing of the precursor Xbp1 mRNA to produce active Xbp1. As mentioned above, activated Xbp1 in turn upregulates the activity of EDEM2. (See Yoshida et al., Cell Structure and Function 31(2): 117-125, 2006; and Olivari, 2005.) Exemplary Xbp1 amino acid sequences are depicted in Table 2, which is cross-referenced to the Sequence Listing.
[0000]
TABLE 2
Animal
SEQ ID NO
% id human
% id mouse
% id hamster
Mouse
9
86
100
92
Hamster
10
86
92
100
Human
11
100
86
86
Zebra fish
12
47
47
48
Consensus
13
100
100
100
[0025] As used herein, the term “antibody” is generally intended to refer to immunoglobulin molecules comprising four polypeptide chains, two heavy (H) chains and two light (L) chains inter-connected by disulfide bonds, as well as multimers thereof (e.g., IgM); however, immunoglobulin molecules consisting of only heavy chains (i.e., lacking light chains) are also encompassed within the definition of the term “antibody”. Each heavy chain comprises a heavy chain variable region (abbreviated herein as HCVR or VH) and a heavy chain constant region. The heavy chain constant region comprises three domains, CH1, CH2 and CH3. Each light chain comprises a light chain variable region (abbreviated herein as LCVR or VL) and a light chain constant region. The light chain constant region comprises one domain (CL1). The VH and VL regions can be further subdivided into regions of hypervariability, termed complementary determining regions (CDRs), interspersed with regions that are more conserved, termed framework regions (FR). Each VH and VL is composed of three CDRs and four FRs, arranged from amino-terminus to carboxy-terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. An “isolated antibody” or “purified antibody” may be substantially free of other cellular material or chemicals.
[0026] The term “specifically binds”, or the like, means that an antibody or antigen-binding fragment thereof forms a complex with an antigen that is relatively stable under physiologic conditions. Specific binding can be characterized by a dissociation constant of at least about 1×10 −6 M or greater. Methods for determining whether two molecules specifically bind are well known in the art and include, for example, equilibrium dialysis, surface plasmon resonance, and the like. An isolated antibody that specifically binds human GDF8 (for example) may, however, have cross-reactivity to other antigens, such as GDF8 molecules from other species (orthologs).
[0027] Various antibodies are used as examples of multi-subunit proteins secreted by cells harboring the polynucleotide encoding a stress-induced mannose-binding lectin. Those examples include anti-GDF8, anti-ANG2, and anti-ANGPTL4 antibodies. These and similar antibodies are described in US Pat. Apps. No. 20110293630, 20110027286, and 20110159015 respectively, which are incorporated herein by reference.
[0028] As used herein, the term “cell” refers to a prokaryotic or eukaryotic cell capable of replicating DNA, transcribing RNA, translating polypeptides, and secreting proteins. Cells include animal cells used in the commercial production of biological products, such as insect cells (e.g., Schneider cells, Sf9 cells, Sf21 cells, Tn-368 cells, BTI-TN-5B1-4 cells; see Jarvis, Methods Enzymol. 463: 191-222, 2009; and Potter et al., Int. Rev. Immunol. 10(2-3): 103-112, 1993) and mammalian cells (e.g., CHO or CHO-K1 cells, COS or COS-7cells, HEK293 cells, PC12 cells, HeLa cells, Hybridoma cells; Trill et al., Curr. Opin. Biotechnol. 6(5): 553-560, 1995; Kipriyanov and Little, Mo. Biotechnol. 12(2): 173-201, 1999). In one embodiment, the cell is a CHO-K1 cell containing the described UPR pathway polynucleotides. For a description of CHO-K1 cells, see also Kao et al., Proc. Nat'l. Acad. Sci. USA 60: 1275-1281, 1968.
[0029] As used herein, the term “promoter” means a genetic sequence generally in cis and located upstream of a protein coding sequence, and which facilitates the transcription of the protein coding sequence. Promoters can be regulated (developmental, tissue specific, or inducible (chemical, temperature)) or constitutively active. In certain embodiments, the polynucleotides that encode proteins are operably linked to a constitutive promoter. By “operably linked”, what is meant is that the protein-encoding polynucleotide is located three-prime (downstream) and cis of the promoter, and under control of the promoter. In certain embodiments, the promoter is a constitutive mammalian promoter, such as the ubiquitin C promoter (see Schorpp et al., Nucl. Acids Res. 24(9): 1787-1788, 1996); Byun et al., Biochem. Biophys. Res. Comm. 332(2): 518-523, 2005) or the CMV-IE promoter (see Addison et al., J. Gen. Virol. 78(7): 1653-1661, 1997; Hunninghake et al., J. Virol. 63(7): 3026-3033, 1989), or the hCMV-IE promoter (human cytomegalovirus immediate early gene promoter) (see Stinski & Roehr, J. Virol. 55(2): 431-441, 1985; Hunninghake et al., J. Virol. 63(7): 3026-3033, 1989).
[0030] As used herein, the phrase “integrated cell density”, or “ICD” means the density of cells in a culture medium taken as an integral over a period of time, expressed as cell-days per mL. In some embodiments, the ICD is measured around the twelfth day of cells in culture.
[0031] As used herein, the term “culture” means both (1) the composition comprising cells, medium, and secreted multi-subunit protein, and (2) the act of incubating the cells in medium, regardless of whether the cells are actively dividing or not. Cells can be cultured in a vessel as small as a 25 mL flask or smaller, and as large as a commercial bioreactor of 10,000 liters or larger. “Medium” refers to the culture medium, which comprises inter alia nutrients, lipids, amino acids, nucleic acids, buffers and trace elements to allow the growth, proliferation, or maintenance of cells, and the production of the multi-subunit protein by the cells. Cell culture media include serum-free and hydrolysate-free defined media as well as media supplemented with sera (e.g., fetal bovine serum (FBS)) or protein hydrolysates. Non-limiting examples of media, which can be commercially acquired, include RPMI medium 1640, Dulbecco's Modified Eagle Medium (DMEM), DMEM/F12 mixture, F10 nutrient mixture, Ham's F12 nutrient mixture, and minimum essential media (MEM).
[0032] As used herein, the phrase “conservatively substituted variant”, as applied to polypeptides, means a polypeptide having an amino acid sequence with one of more conservative amino acid substitutions. A “conservative amino acid substitution” is one in which an amino acid residue is substituted by another amino acid residue having a side chain (R group) with similar chemical properties (e.g., charge or hydrophobicity). In general, a conservative amino acid substitution will not substantially change the functional properties of a protein. In cases where two or more amino acid sequences differ from each other by conservative substitutions, the percent or degree of similarity may be adjusted upwards to correct for the conservative nature of the substitution. Means for making this adjustment are well known to those of skill in the art. See, e.g., Pearson (1994) Methods Mol. Biol. 24: 307-331, which is herein incorporated by reference. Examples of groups of amino acids that have side chains with similar chemical properties include 1) aliphatic side chains: glycine, alanine, valine, leucine and isoleucine; 2) aliphatic-hydroxyl side chains: serine and threonine; 3) amide-containing side chains: asparagine and glutamine; 4) aromatic side chains: phenylalanine, tyrosine, and tryptophan; 5) basic side chains: lysine, arginine, and histidine; 6) acidic side chains: aspartate and glutamate, and 7) sulfur-containing side chains: cysteine and methionine. Preferred conservative amino acids substitution groups are: valine-leucine-isoleucine, phenylalanine-tyrosine, lysine-arginine, alanine-valine, glutamate-aspartate, and asparagine-glutamine. Alternatively, a conservative replacement is any change having a positive value in the PAM250 log-likelihood matrix disclosed in Gonnet et al. (1992) Science 256: 1443-45, herein incorporated by reference. A “moderately conservative” replacement is any change having a nonnegative value in the PAM250 log-likelihood matrix.
Embodiments
The Cell
[0033] In one aspect, the invention provides a cell useful in the production of a protein having therapeutic or research utility. In some embodiments, the protein consists of multiple subunits, which must be properly folded and assembled to produce sufficient quantities of active protein. Antibodies are an example of multi-subunit proteins having therapeutic or research utility. In some embodiments, the cell harbors a recombinant genetic construct (i.e., a polynucleotide) that encodes one or more of the individual subunits of the multi-subunit protein. In other embodiments, the genetic construct encoding the individual polypeptide subunits is naturally occurring, such as for example the nucleic acid sequences encoding the subunits of an antibody in a B cell.
[0034] To facilitate the proper assembly and secretion of the multi-subunit protein, the cell contains a recombinant polynucleotide that encodes a stress-induced mannose-binding lectin, which in some embodiments is a component of the ERAD. In some embodiments, the stress-induced mannose-binding lectin is an endoplasmic reticulum degradation-enhancing alpha-mannosidase-like protein 2 (EDEM2). It is envisioned that any encoded EDEM2 or conservatively-substituted variant can be successfully employed in the instant invention. Table 1 lists some examples of vertebrate EDEM2 proteins. A multiple pairwise comparison of those protein sequences, which was performed using the Clustal W program of Thompson et al., Nucl. Acids Rev. 22(22): 4673-80, 1994 (see also Yuan et al., Bioinformatics 15(10): 862-3, 1999), revealed that each of the disclosed EDEM2 polynucleotide sequences is at least 69% identical to each other EDEM2 sequence. A Clustal W comparison of the disclosed mammalian EDEM2 sequences revealed that each sequence is at least 92% identical to the other. Thus, in some embodiments, the cell contains a polynucleotide that encodes an EDEM2 polypeptide having a sequence that is at least 92% to any one of a mammalian EDEM2. A consensus EDEM2 amino acid sequence was built by aligning a mouse, rat, hamster, chimpanzee, and human EDEM2 polypeptide amino acid sequences. That consensus sequence is depicted as SEQ ID NO: 8. Thus, in some embodiments, the cell contains a polynucleotide that encodes an EDEM2 polypeptide having an amino acid sequence of SEQ ID NO: 8.
[0035] In various embodiments, the cell contains a recombinant polynucleotide that encodes an EDEM2 polypeptide having an amino acid sequence that is at least 92% identical to the mouse EDEM2 (mEDEM2) amino acid sequence; and in a particular embodiment, the polypeptide is mEDEM2 or a conservatively substituted variant thereof.
[0036] In some embodiments, the multi-subunit protein is an antibody, and the cell contains a polynucleotide encoding any one or more of a polypeptide comprising an amino acid sequence of SEQ ID NO: 43, SEQ ID NO: 44, SEQ ID NO: 45, and SEQ ID NO: 46. SEQ ID NO: 43 and 44 each represent consensus sequences of the roughly N-terminal and C-terminal portions, respectively, of particular antibody heavy chains. Thus, the polynucleotide encoding a protein subunit in one embodiment encodes a polypeptide comprising both SEQ ID NO: 43 and SEQ ID NO: 44. SEQ ID NO: 45 and 46 each represent consensus sequences of the roughly N-terminal and C-terminal portions, respectively, of particular antibody light chains. Thus, the polynucleotide encoding a protein subunit in one embodiment encodes a polypeptide comprising both SEQ ID NO: 45 and SEQ ID NO: 46. In some embodiments, in addition to the recombinant polynucleotide encoding the EDEM2 protein, the cell contains at least two polynucleotides, each of which encodes a particular subunit of the multi-subunit protein. For example, and as exemplified below, the cell contains a polynucleotide encoding an antibody heavy chain comprising an amino acid sequence of SEQ ID NO: 43 and SEQ ID NO: 44, and another polynucleotide encoding an antibody light chain comprising an amino acid sequence of SEQ ID NO: 45 and SEQ ID NO: 46.
[0037] In some embodiments, the cell, in addition to containing the stress-response polynucleotide and one or more polynucleotides encoding a polypeptide subunit, as described above, also contains a polynucleotide that encodes an unfolded protein response transcription factor that operates upstream of EDEM2. The upstream transcription factor is in some cases the spliced form of an XBP1. It is envisioned that any encoded XBP1 can be successfully employed in the instant invention. Table 2 lists some examples of sequences of vertebrate XBP1 spliced-form polypeptides. A multiple pairwise comparison of those polypeptide sequences, which was performed using Clustal W (Thompson 1994; Yuan 1999), revealed that each of the disclosed spliced XBP1 polynucleotide sequences is at least 48% identical to each other XBP1 sequence. A Clustal W comparison of the disclosed mammalian XBP1 sequences revealed that each sequence is at least 86% identical to the other. Thus, in some embodiments, the cell contains a polynucleotide that encodes a spliced-form of an XBP1 polypeptide having a sequence that is at least 86% to any one of a mammalian spliced XBP1. A consensus XBP1 amino acid sequence was built by aligning a mouse, hamster, and human XBP1 amino acid sequences. That consensus sequence is depicted as SEQ ID NO: 13. Thus, in some embodiments, the cell contains a polynucleotide that encodes an XBP1 polypeptide having an amino acid sequence of SEQ ID NO: 13.
[0038] In various embodiments, the cell contains a polynucleotide that encodes an XBP1 polypeptide having an amino acid sequence that is at least 86% identical to the mouse XBP1 (mXBP1) amino acid sequence (SEQ ID NO: 9); and in a particular embodiment, the polypeptide is mXBP1, or a conservatively substituted variant thereof.
[0039] The invention envisions that any cell may be used to harbor the lectin-encoding polypeptide for the production of a properly folded and active multi-subunit protein. Such cells include the well-known protein production cells such as the bacterium Escherichia coli and similar prokaryotic cells, the yeasts Pichia pastoris and other Pichia and non-pichia yeasts, plant cell explants, such as those of Nicotiana , insect cells, such as Schneider 2 cells, Sf9 and Sf21, and the Trichoplusia ni -derived High Five cells, and the mammalian cells typically used in bioproduction, such as CHO, CHO-K1, COS, HeLa, HEK293, Jurkat, and PC12 cells. In some embodiments, the cell is a CHO-K1 or a modified CHO-K1 cell such as that which is taught in U.S. Pat. Nos. 7,435,553, 7,514,545, and 7,771,997, as well as U.S. Published Patent Application No. US 2010-0304436 A1, each of which is incorporated herein by reference in its entirety.
[0040] In some particular embodiments, the invention provides ex vivo a CHO-K1 cell that contains (1) a mEDEM2-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 16, (2) an XBP1-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 18, (3) an antibody heavy chain-encoding polynucleotide comprising a nucleotide sequence that encodes a polypeptide comprising the amino acid sequences of SEQ ID NO: 43 and 44, and (4) an antibody light chain-encoding polynucleotide comprising a nucleotide sequence that encodes a polypeptide comprising the amino acid sequences of SEQ ID NO: 45 and 46.
[0041] In one particular embodiment, the invention provides ex vivo a CHO-K1 cell that contains (1) a mEDEM2-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 16, (2) an XBP1-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO:18, (3) an antibody heavy chain-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 23, and (4) an antibody light chain-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 25.
[0042] In another particular embodiment, the invention provides ex vivo a CHO-K1 cell that contains (1) a mEDEM2-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 16, (2) an XBP1-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 18, (3) an antibody heavy chain-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 31, and (4) an antibody light chain-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 33.
[0043] In yet another particular embodiment, the invention provides ex vivo a CHO-K1 cell that contains (1) a mEDEM2-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 16, (2) an XBP1-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 18, (3) an antibody heavy chain-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 39, and (4) an antibody light chain-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 41.
[0044] The Cell Line
[0045] In another aspect, the invention provides a cell line, which comprises a plurality of cells descended by clonal expansion from a cell described above. At least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98%, at least 99%, or about 100% of the constituent cells of the cell line contain a recombinant polynucleotide that encodes a stress-induced mannose-binding lectin, which in some embodiments is a component of the ERAD. In some embodiments, the stress-induced mannose-binding lectin is an endoplasmic reticulum degradation-enhancing alpha-mannosidase-like protein 2 (EDEM2). It is envisioned that any encoded EDEM2 or conservatively-substituted variant thereof can be successfully employed in the instant invention. Table 1, as discussed in the previous section, lists some examples of vertebrate EDEM2 proteins. In some embodiments, the constituent cell contains a polynucleotide that encodes an EDEM2 polypeptide having a sequence that is at least 92% identical to any mammalian EDEM2. In some embodiments, the constituent cell contains a polynucleotide that encodes an EDEM2 polypeptide having the mammalian consensus amino acid sequence of SEQ ID NO: 8. In some embodiments, the constituent cell contains a recombinant polynucleotide of SEQ ID NO: 1 or a conservatively substituted variant thereof.
[0046] In some embodiments, the multi-subunit protein that is produced by the cell line is an antibody, and the constituent cell of the cell line contains a polynucleotide encoding any one or more of a polypeptide comprising an amino acid sequence of SEQ ID NO: 43 and SEQ ID NO: 44 (which represent consensus sequences of the N-terminal and C-terminal portions, respectively, of particular antibody heavy chains), and SEQ ID NO: 45 and SEQ ID NO: 46 (which represent consensus sequences of the N-terminal and C-terminal portions, respectively, of particular antibody light chains). In some embodiments, in addition to the recombinant polynucleotide encoding the EDEM2 protein, the constituent cell of the cell line contains at least two polynucleotides, each of which encodes a particular subunit of the multi-subunit protein. For example, the constituent cell contains a polynucleotide encoding an antibody heavy chain comprising an amino acid sequence of SEQ ID NO: 43 and SEQ ID NO: 44, and another polynucleotide encoding an antibody light chain comprising an amino acid sequence of SEQ ID NO: 45 and SEQ ID NO: 46.
[0047] In some embodiments, the constituent cell, in addition to containing the stress-response polynucleotide and one or more polynucleotides encoding a polypeptide subunit, as described above, also contains a polynucleotide that encodes an unfolded protein response transcription factor, which operates upstream of EDEM2, such as a spliced form of an XBP1. It is envisioned that any encoded XBP1 can be successfully employed in the instant invention. Table 2, as discussed in the preceding section, lists some examples of sequences of vertebrate XBP1 spliced-form polypeptides. Clustal W analysis of those sequences revealed that each of the disclosed spliced XBP1 polynucleotide sequences is at least 48% identical to each other XBP1 sequence; and a comparison of the mammalian XBP1 sequences revealed that each sequence is at least 86% identical to the other. Thus, in some embodiments, the constituent cell of the cell line contains a polynucleotide that encodes a spliced-form of an XBP1 polypeptide having a sequence that is at least 86% to any one of a mammalian spliced XBP1. In some embodiments, the constituent cell contains a polynucleotide that encodes an XBP1 polypeptide having a consensus amino acid sequence of SEQ ID NO: 13.
[0048] In various embodiments, the cell contains a polynucleotide that encodes an XBP1 polypeptide having an amino acid sequence that is at least 86% identical to the mouse XBP1 (mXBP1) amino acid sequence (SEQ ID NO: 9); and in a particular embodiment, the polypeptide is mXBP1 of SEQ ID NO: 9, or a conservatively substituted variant thereof.
[0049] The invention envisions that the cell line comprises constituent cells whose parent is selected from a list of well-known protein production cells such as, e.g., the bacterium Escherichia coli and similar prokaryotic cells, the yeasts Pichia pastoris and other Pichia and non-pichia yeasts, plant cell explants, such as those of Nicotiana , insect cells, such as Schneider 2 cells, Sf9 and Sf21, and the Trichoplusia ni -derived High Five cells, and the mammalian cells typically used in bioporduction, such as CHO, CHO-K1, COS, HeLa, HEK293, Jurkat, and PC12 cells. In some embodiments, the cell is a CHO-K1 or a modified CHO-K1 cell, such as that which is taught in U.S. Pat. Nos. 7,435,553, 7,514,545, and 7,771,997, as well as U.S. Published Patent Application No. US 2010-0304436 A1.
[0050] In some embodiments, the cell line, which is cultured in media, is capable of producing the multi-subunit protein and secreting the properly assembled multi-subunit protein into the media to a titer that is at least 3 g/L, at least 5 g/L, or at least 8 g/L.
[0051] Furthermore, the constituent cells of the cell line are capable proliferating in culture to such an extent as to attain an integrated cell density that is about 30% greater than the integrated cell density of a cell line that does not contain the recombinant polynucleotide encoding the stress-induced mannose-binding lectin. In some cases, the cell line is able to attain an integrated cell density that is at least about 50% greater, at least 60% greater, or at least 90% greater than the integrated cell density of a cell line that does not contain the recombinant polynucleotide that encodes a stress-induced mannose-binding lectin. In some embodiments, the integrated cell density of the cell line is assessed after about 12 days in culture.
[0052] In some particular embodiments, the invention provides a cell-line comprising clonally-derived constituent cells, wherein the constituent cell is a CHO-K1 cell that contains (1) a mEDEM2-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 16, (2) an XBP1-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 18, (3) an antibody heavy chain-encoding polynucleotide comprising a nucleotide sequence that encodes a polypeptide comprising the amino acid sequences of SEQ ID NO: 43 and 44, and (4) an antibody light chain-encoding polynucleotide comprising a nucleotide sequence that encodes a polypeptide comprising the amino acid sequences of SEQ ID NO: 45 and 46.
[0053] In one particular embodiment, the invention provides a cell-line comprising clonally-derived constituent cells, wherein the constituent cell is a CHO-K1 cell that contains (1) a mEDEM2-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 16, (2) an XBP1-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 18, (3) an antibody heavy chain-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 23, and (4) an antibody light chain-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 25.
[0054] In another particular embodiment, the invention provides a cell-line comprising clonally-derived constituent cells, wherein the constituent cell is a CHO-K1 cell that contains (1) a mEDEM2-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 16, (2) an XBP1-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 18, (3) an antibody heavy chain-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 31, and (4) an antibody light chain-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 33.
[0055] In yet another particular embodiment, the invention provides a cell-line comprising clonally-derived constituent cells, wherein the constituent cell is a CHO-K1 cell that contains (1) a mEDEM2-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 16, (2) an XBP1-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 18, (3) an antibody heavy chain-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 39, and (4) an antibody light chain-encoding polynucleotide comprising a nucleotide sequence of SEQ ID NO: 41.
[0056] The EDEM2 Polynucleotide
[0057] In another aspect, the invention provides a polynucleotide that encodes an EDEM2 protein. The EDEM2-encoding polynucleotide is recombinant and can be manufactured, stored, used or expressed in vitro, as in a test tube, or an in vitro translation system, or in vivo, such as in a cell, which can be ex vivo, as in a cell culture, or in vivo, as in an organism. In some embodiments, the EDEM2-encoding polynucleotide is within a gene, meaning that it is under the control of and down stream of a promoter, and up stream of a polyadenylation site. The EDEM2-encoding polynucleotide or gene can be within a plasmid or other circular or linear vector. The EDEM2-encoding polynucleotide or gene can be within a circular or linear DNA construct, which can be within a cell as an episome or integrated into the cellular genome.
[0058] As described above, the EDEM2-encoding polynucleotide encodes any ortholog, homolog or conservatively substituted EDEM2 polypeptide of Table 1, or an EDEM2 polypeptide having an amino acid sequence that is at least 92% identical to any one of SEQ ID NO: 1-5 and 8, including the mammalian consensus sequence of SEQ ID NO: 8.
[0059] In some cases, the recombinant or isolated EDEM2-encoding polynucleotide is operably linked to a mammalian promoter. The promoter can be any promoter, but in some cases it is a mammalian promoter, such as for example a ubiquitin C promoter.
[0060] In a particular embodiment, the EDEM2-encoding polynucleotide essentially consists of, from 5′ to 3′, a promoter, such as a ubiquitin C promoter, followed by an optional intron, such as a beta globin intron, followed by an EDEM2 coding sequence, followed by a polyadenylation sequence, such as an SV40pA sequence. A specific example, which is also a particular embodiment, of such an EDEM2-encoding polynucleotide is described by SEQ ID NO: 16. Conserved variants of that sequence are also envisioned to be embodiments of the invention.
[0061] In some cases, the recombinant EDEM2-encoding polynucleotide is part of a plasmid, which can be linear, circular, episomal, integrated, a static DNA construct, or a vector for delivering the EDEM2 gene or expressing the EDEM2 protein. In one particular embodiment, the plasmid contains (1) an EDEM2 gene, which is under the control of a ubiquitin C promoter and terminates with an SV40 polyadenylation signal, and (2) a selectable marker, such as a polynucleotide encoding a polypeptide that confers resistance to zeocin or a polynucleotide encoding a polypeptide that confers resistance to neomycin, under the control of a promoter, such as an SV40 promoter, and terminated with a polyadenylation sequence, such as a PGK pA sequence. In one particular embodiment, the plasmid comprises, in a circular format running in a 5′ to 3′ direction, a ubiquitin C promoter, a beta globin intron, an EDEM2 coding sequence, an SV40 pA sequence, an SV40 promoter, a neomycin-resistance coding sequence, and a PGK pA sequence. A specific example of this embodiment is exemplified by a plasmid having the sequence of SEQ ID NO: 14. In another particular embodiment, the plasmid comprises, in a circular format running in a 5′ to 3′ direction, a ubiquitin C promoter, a beta globin intron, an EDEM2 coding sequence, an SV40 pA sequence, an SV40 promoter, a zeocin-resistance coding sequence, and a PGK pA sequence. A specific example of this embodiment is exemplified by a plasmid having the sequence of SEQ ID NO: 15.
[0062] The XBP1 Polynucleotide
[0063] In another aspect, the invention provides a polynucleotide that encodes an XBP1 protein. The XBP1-encoding polynucleotide is recombinant and can be manufactured, stored, used or expressed in vitro, as in a test tube, or an in vitro translation system, or in vivo, such as in a cell, which can be ex vivo, as in a cell culture, or in vivo, as in an organism. In some embodiments, the XBP1-encoding polynucleotide is within a gene, meaning that it is under the control of and down stream of a promoter, and up stream of a polyadenylation site. The XBP1-encoding polynucleotide can be within a plasmid or other circular or linear vector. The XBP1-encoding polynucleotide or gene can be within a circular or linear DNA construct, which can be within a cell as an episome, or integrated into the cellular genome.
[0064] As described above, the XBP1-encoding polynucleotide encodes any ortholog, homolog or conservatively substituted XBP1 polypeptide of Table 2, or an XBP1 polypeptide having an amino acid sequence that is at least 86% identical to any one of SEQ ID NO: 9, 10, and 11, including the mammalian consensus sequence of SEQ ID NO: 13.
[0065] In some cases, the recombinant or isolated XBP1-encoding polynucleotide is operably linked to a mammalian promoter. The promoter can be any promoter, but in some cases it is a mammalian promoter, such as for example a ubiquitin C promoter.
[0066] In a particular embodiment, the XBP1-encoding polynucleotide essentially consists of, from 5′ to 3′, a promoter, such as a ubiquitin C promoter, followed by an optional intron, such as a beta globin intron, followed by an XBP1 coding sequence, followed by a polyadenylation sequence, such as an SV40 pA sequence. SEQ ID NO: 18 describes an example of an XBP1-encoding polynucleotide. Conserved variants of that exemplary sequence are also envisioned to be embodiments of the invention.
[0067] In some cases, the recombinant XBP1-encoding polynucleotide is part of a plasmid, which can be linear, circular, episomal, integrated, a static DNA construct, or a vector for delivering the XBP1 gene or expressing the spliced and active XBP1 protein. In one particular embodiment, the plasmid contains (1) an XBP1 gene, which is under the control of a ubiquitin C promoter and terminates with an SV40 polyadenylation signal, and (2) a selectable marker, such as a polynucleotide encoding a polypeptide that confers resistance to zeocin or a polynucleotide encoding a polypeptide that confers resistance to neomycin, under the control of a promoter, such as an SV40 promoter, and terminated with a polyadenylation sequence, such as a PGK pA sequence. In one particular embodiment, the plasmid comprises, in a circular format running in a 5′ to 3′ direction, a ubiquitin C promoter, a beta globin intron, an XBP1 coding sequence, an SV40 pA sequence, an SV40 promoter, a zeocin-resistance coding sequence, and a PGK pA sequence. A specific example of this embodiment is exemplified by a circular plasmid having the sequence of SEQ ID NO: 17.
[0068] The Antibody Heavy and Light Chain-Encoding Polynucleotides
[0069] In another aspect, the invention provides a polynucleotide that encodes an antibody heavy chain polypeptide (HC). The HC-encoding polynucleotide is recombinant and can be manufactured, stored, used or expressed in vitro, as in a test tube, or an in vitro translation system, or in vivo, such as in a cell, which can be ex vivo, as in a cell culture, or in vivo, as in an organism. In some embodiments, the HC-encoding polynucleotide is within a gene, meaning that it is under the control of and down stream from a promoter, and up stream of a polyadenylation site. The HC-encoding polynucleotide may be within a plasmid or other circular or linear vector. The HC-encoding polynucleotide or gene may be within a circular or linear DNA construct, which may be within a cell as an episome or integrated into the cellular genome.
[0070] In some cases, the recombinant or isolated HC-encoding polynucleotide is operably linked to a mammalian promoter. The promoter can be any promoter, but in some cases it is a mammalian promoter, such as for example a ubiquitin C promoter or an hCMV-IE promoter.
[0071] In a particular embodiment, the HC-encoding polynucleotide is an HC gene, which essentially comprises, from 5′ to 3′, a promoter, for example an hCMV-IE promoter, followed by an optional intron, such as a beta globin intron, followed by a heavy chain coding sequence, such as for example a sequence encoding an amino acid sequence of SEQ ID NO: 43 and 44, SEQ ID NO: 19, SEQ ID NO: 27, or SEQ ID NO: 35, followed by a polyadenylation sequence, for example an SV40 pA sequence. A specific example of an HC gene is described by SEQ ID NO: 23, SEQ ID NO: 31, or SEQ ID NO: 39. Conserved variants of any one of these sequences are also envisioned to be embodiments of the invention.
[0072] In some cases, the recombinant HC-encoding polynucleotide is part of a plasmid, which can be linear, circular, episomal, integrated, a static DNA construct, or a vector for delivering the heavy chain gene or expressing the heavy chain subunit. In one particular embodiment, the plasmid contains (1) an HC gene, which is under the control of an hCMV-IE promoter and terminates with an SV40 polyadenylation signal, and (2) a selectable marker, such as a polynucleotide encoding a polypeptide that confers resistance to hygromycin, under the control of a promoter, such as an SV40 promoter, and terminated with a polyadenylation sequence, such as a PGK pA sequence. In one particular embodiment, the plasmid comprises, in a circular format running in a 5′ to 3′ direction, an hCMV-IE promoter, a beta globin intron, an antibody heavy chain coding sequence (which encodes a HC having an amino acid of SEQ ID NO: 43 and 44, SEQ ID NO: 19, SEQ ID NO: 27, or SEQ ID NO: 35), an SV40 pA sequence, an SV40 promoter, a hygromycin-resistance coding sequence, and a PGK pA sequence. A specific example and particular embodiment of such a plasmid containing an HC gene is described by SEQ ID NO: 24, SEQ ID NO: 32, or SEQ ID NO: 40. Conserved variants of any one of these sequences are also envisioned to be embodiments of the invention.
[0073] In another aspect, the invention provides a polynucleotide that encodes an antibody light chain polypeptide (LC). The LC-encoding polynucleotide is recombinant and can be manufactured, stored, used or expressed in vitro, as in a test tube, or an in vitro translation system, or in vivo, such as in a cell, which can be ex vivo, as in a cell culture, or in vivo, as in an organism. In some embodiments, the LC-encoding polynucleotide is within a gene, meaning that it is under the control of and down stream from a promoter, and up stream of a polyadenylation site. The LC-encoding polynucleotide or gene may be within a plasmid or other circular or linear vector. The LC-encoding polynucleotide or gene may be within a circular or linear DNA construct, which may be within a cell as an episome or integrated into the cellular genome.
[0074] In some cases, the recombinant or isolated LC-encoding polynucleotide is operably linked to a mammalian promoter. The promoter can be any promoter, but in some cases it is a mammalian promoter, such as, e.g., a ubiquitin C promoter or an hCMV-IE promoter.
[0075] In a particular embodiment, the LC-encoding polynucleotide is an LC gene, which essentially comprises, from 5′ to 3′, a promoter, for example an hCMV-IE promoter, followed by an optional intron, such as a beta globin intron, followed by a light chain coding sequence, such as for example a sequence encoding an amino acid sequence of SEQ ID NO: 45 and 46, SEQ ID NO: 21, SEQ ID NO: 29, or SEQ ID NO: 37, followed by a polyadenylation sequence, such as an SV40 pA sequence. A specific example and particular embodiment of such an LC gene is described by SEQ ID NO: 25, SEQ ID NO: 33, or SEQ ID NO: 41. Conserved variants of any one of these sequences are also envisioned to be embodiments of the invention.
[0076] In some cases, the recombinant LC-encoding polynucleotide is part of a plasmid, which may be linear, circular, episomal, integrated, a static DNA construct, or a vector for delivering the light chain gene or expressing the light chain subunit. In one particular embodiment, the plasmid contains (1) an LC gene, which is under the control of an hCMV-IE promoter and terminates with an SV40 polyadenylation signal, and (2) a selectable marker, such as a polynucleotide encoding a polypeptide that confers resistance to hygromycin, under the control of a promoter, such as an SV40 promoter, and terminated with a polyadenylation sequence, such as a PGK pA sequence. In one particular embodiment, the plasmid comprises, in a circular format running in a 5′ to 3′ direction, an hCMV-IE promoter, a beta globin intron, an antibody light chain coding sequence (which encodes a LC having an amino acid of SEQ ID NO: 45 and 46, SEQ ID NO: 21, SEQ ID NO: 29, or SEQ ID NO: 37), an SV40 pA sequence, an SV40 promoter, a hygromycin-resistance coding sequence, and a PGK pA sequence. A specific example and particular embodiment of such a plasmid containing an LC gene is described by SEQ ID NO: 26, SEQ ID NO: 34, or SEQ ID NO: 42. Conserved variants of any one of these sequences are also envisioned to be embodiments of the invention.
[0077] Methods of Manufacturing Multi-Subunit Proteins
[0078] In another aspect, the invention provides a method for manufacturing a multi-subunit protein by culturing a cell, or a constituent cell of a cell line, which is capable of producing and secreting relatively large amounts of a properly assembled multi-subunit protein, in a medium, wherein the multi-subunit component is secreted into the medium at a relatively high titer. The cell utilized in this manufacturing process is a cell described in the foregoing aspects, which contains an ERAD lectin-encoding polynucleotide described herein.
[0079] Methods of culturing cells, and in particular mammalian cells, for the purpose of producing useful recombinant proteins is well-known in the art (e.g., see De Jesus & Wurm, Eur. J. Pharm. Biopharm. 78:184-188, 2011, and references cited therein). Briefly, cells containing the described polynucleotides are cultured in media, which may contain sera or hydrolysates, or may be chemically defined and optimized for protein production. The cultures may be fed-batch cultures or continuous cultures, as in a chemostat. The cells may be cultured in lab bench size flasks (˜25 mL), production scale-up bioreactors (1-5 L), or industrial scale bioreactors (5,000-25,000 L). Production runs may last for several weeks to a month, during which time the multi-subunit protein is secreted into the media.
[0080] The subject cell has an enhanced ability to produce and secrete properly assembled multi-subunit proteins. In some embodiments, the multi-subunit protein, for example an antibody, is secreted into the media at a rate of at least 94 ρg/cell/day, at least 37 ρg/cell/day, or at least 39 ρg/cell/day. In some embodiments, the multi-subunit protein attains a titer of at least at least 3 g/L, at least 5 g/L, at least 6 g/L, or at least 8 g/L after about twelve days of culture.
[0081] Furthermore, the subject cell has an enhanced ability to proliferate and attain a relatively high cell density, further optimizing productivity. In some embodiments, the cell or cell-line seed train attains an integrated cell density in culture of at least 5×10 7 cell-day/mL, at least 1×10 8 cell-day/mL or at least 1.5×10 8 cell-day/mL.
[0082] Optionally, the secreted multi-subunit protein is subsequently purified from the medium into which it was secreted. Protein purification methods are well-known in the art (see e.g., Kelley, mAbs 1(5):443-452). In some embodiments, the protein is harvested by centrifugation to remove the cells from the liquid media supernatant, followed by various chromatography steps and a filtration step to remove inter alia viruses and other contaminants or adulterants. In some embodiments, the chromatography steps include an ion exchange step, such as cation-exchange or anion-exchange. Various affinity chromatographic media may also be employed, such as protein A chromatography for the purification of antibodies.
[0083] Optionally, the manufacturing method may include the antecedent steps of creating the cell. Thus, in some embodiments, the method of manufacturing the multi-subunit protein comprises the step of transfecting the cell with the vector that encodes the stress-induced mannose-binding lectin, as described above, followed by selecting stable integrants thereof. Non-limiting examples of vectors include those genetic constructs that contain a polynucleotide that encodes an EDEM2 having an amino acid sequence of any one of SEQ ID NO: 1-8, an amino acid sequence that is at least 92% identical to any one of SEQ ID NO: 1-8, or any one of a conservatively substituted variant of SEQ ID NO: 1-8. Useful vectors also include, for example, a plasmid harboring the gene of SEQ ID NO: 16, the plasmid of SEQ ID NO: 15, and the plasmid of SEQ ID NO: 14. One should keep in mind that the plasmid sequences (e.g., SEQ ID NO: 14, 15, 17, 24, 26, 32, 34, 40, and 42) are circular sequences described in a linear manner in the sequence listing. Thus, in those cases, the 3-prime-most nucleotide of the written sequence may be considered to be immediately 5-prime of the 5-prime-most nucleotide of the sequence as written. In the example of the plasmid of SEQ ID NO: 14, transformants are selected through resistance to neomycin; for SEQ ID NO: 15, by selection through ZEOCIN resistance.
[0084] Detailed methods for the construction of polynucleotides and vectors comprising same, are described in U.S. Pat. Nos. 7,435,553 and 7,771,997, which are incorporated herein by reference, and in, e.g., Zwarthoff et al., J. Gen. Virol. 66(4):685-91, 1985; Mory et al., DNA. 5(3):181-93, 1986; and Pichler et al., Biotechnol. Bioeng. 108(2):386-94, 2011.
[0085] The starting cell, into which the vector that encodes the stress-induced mannose-binding lectin is placed, may already contain the constructs or genetic elements encoding or regulating the expression of the subunits of the multi-subunit protein, or XBP1 for those embodiments utilizing XBP1. Alternatively, the vector that encodes the stress-induced mannose-binding lectin may be put inside the cell first, and followed by the other constructs.
[0086] Multi-Subunit Proteins Manufactured by the Process
[0087] In another aspect, the invention provides a multi-subunit protein that is made according to the process disclosed herein. Given the inclusion of one or more elements that facilitate the proper folding, assembly, and post-translational modification of a multi-subunit protein, such as an antibody, one of ordinary skill in the art would reasonably expect such a protein to have distinct structural and functional qualities. For example, an antibody manufactured by the disclosed process is reasonably believed to have a particular glycosylation pattern and a quantitatively greater proportion of non-aggregated heterotetramers.
EXAMPLES
[0088] The following examples are presented so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the methods and compositions of the invention, and are not intended to limit the scope of what the inventors regard as their invention. Efforts have been made to ensure accuracy with respect to numbers used (e.g., amounts, temperature, etc.) but some experimental errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by mole, molecular weight is average molecular weight, percent concentration (%) means the mass of the solute in grams divided by the volume of the solution in milliliters times 100% (e.g., 10% substance X means 0.1 gram of substance X per milliliter of solution), temperature is in degrees Centigrade, and pressure is at or near atmospheric pressure.
Example 1
Cell Lines
[0089] CHO-K1 derived host cell line was transfected with two plasmids encoding heavy and light chain of a human antibody. Both plasmids contain the hph gene conferring resistance to hygromycin B (Asselbergs and Pronk, 1992, Mol. Biol. Rep., 17(1):61-70). Cells were transfected using LIPOFECTAMIN reagent (Invitrogen cat.#18324020). Briefly, one day before transfection 3.5 million cells were plated on a 10 cm plate in complete F12 (Invitrogen cat.#11765) containing 10% fetal bovine serum (FBS) (Invitrogen cat.#10100). On the day of transfection the cells were washed once and medium was replaced with OPTIMEM from (Invitrogen cat.#31985). DNA/Lipofectamin complexes were prepared in OPTIMEM medium and then added to the cells. The medium was changed again to the complete F12 with 10% FBS 6 hours later. The stable integration of the plasmids was selected using hygromycin B selection agent at 400 μg/ml. Clonal antibody expressing cell lines were isolated using the FASTR technology (described in the U.S. Pat. No. 6,919,183, which is herein incorporated by reference).
[0090] The antibody expressing lines were then re-transfected with the EDEM2 encoding plasmid. EDEM2 plasmids contained either neomycin phosphotransferase (plasmid construct designated “p3”) or sh ble (plasmid “p7”) genes to confer resistance to either G418 or zeocin respectively. The same transfection method was used. Depending on the selectable marker, cells were selected with either G418 or zeocin at 400 μg/ml or 250 μg/ml, respectively. The clonal cell lines were then isolated using FASTR technology.
[0000]
TABLE 3
Cell Lines
Name
Enhancers
Constructs
Protein
C1
EDEM2 + XBP1
HC/LC = p1/p2
αAng2
C2
XBP1
EDEM2 = p3
XBP1 = p4
C3
EDEM2 + XBP1
HC/LC = p5/p6
αGDF8
C4
XBP1
EDEM2 = p7
C5
EDEM2
XBP1 = p4
C6
EDEM2 + XBP1
HC/LC = p8/p9
αAngPtl4
C7
XBP1
EDEM2 = p3
XBP1 = p4
Example 2
[0091] The antibody production was evaluated in a scaled-down 12-day fed batch process using shaker flasks. In this method the cells were seeded in a shaker flask at the density of 0.8 million cells per mL in the production medium (defined media with high amino acid). The culture was maintained for about 12 days, and was supplemented with three feeds as well as glucose. The viable cell density, and antibody titer were monitored throughout the batch.
[0092] To determine the effect of mEDEM2 on enhanced protein production, the production of proteins by CHO cell lines containing mEDEM2 and mXBP1 were compared to production by control cells that contained mXBP1, but not mEDEM2. Protein titers were higher in those cell lines expressing mEDEM2 versus those cell lines that did not express mEDEM2.
[0000]
TABLE 4
TITERS
Production rate
Titre g/L
Cell Line
Enhancers
(ρg/cell/day)
(% increase)
C1
EDEM2 + XBP1
39
8.1 (93)
C2
XBP1
39
4.2
C3
EDEM2 + XBP1
37
5.9 (55)
C8
XBP1
32
3.8
C6
EDEM2 + XBP1
94
5.3 (152)
C7
XBP1
52
2.1
C5
EDEM2
29
3.1 (343)
C9
—
9
0.7
Example 3
Integrated Cell Days
[0093] Integrated Cell Days (“ICD”) is a phrase used to describe the growth of the culture throughout the fed batch process. In the course of the 12-day production assay, we monitored viable cell density on days 0, 3, 5, 7, 10, and 12. This data was then plotted against time. ICD is the integral of viable cell density, calculated as the area under the cell density curve. EDEM2 transfected lines have higher ICD in a 12-day fed batch process (see Table 5).
[0000]
TABLE 5
INTEGRATED CELL DENSITIES
ICD 10 6 cell-day/mL
Cell Line
Enhancers
(% increase)
C1
EDEM2 + XBP1
205 (93)
C2
XBP1
106
C3
EDEM2 + XBP1
157 (34)
C4
XBP1
117
C6
EDEM2 + XBP1
56 (51)
C7
XBP1
37
C5
EDEM2
116 (59)
C9
—
73
Example 4
Anti-GDF8 Antibody Production
[0094] The effect of ectopic expression of EDEM2, XBP1, or both on the production of an anti-GDF8 antibody having a heavy chain sequence of SEQ ID NO: 19 and a light chain sequence of SEQ ID NO: 21 was examined. Individual cell-lines were examined for titer and integrated cell density and placed into “bins”, or ranges of values. Ectopic expression of EDEM2 significantly increased the number of cell lines that express antibody in the 5-6 g/L titer range. The combination of XBP1 and EDEM2 showed more than an additive effect toward the increase in high titer cell lines. The expression of EDEM2 in the antibody secreting cells also significantly increased the number of cell lines that attain a high ICD (see Table 6).
[0000]
TABLE 6
ICD Bins
Titre Bins (g/L)
(10 6 cell-day/mL)
construct
<1
1-3
3-5
5-6
30-50
50-100
100-200
E + X
0%
33.3%
44.4%
22.2%
11.1%
50%
38.9%
X
0%
37.5%
54%
8.3%
14.3%
85.7%
0%
E
0%
33%
60%
7%
0%
27%
73%
—
82%
18%
0%
0%
13%
67%
21% | The present invention relates to discovery of the ectopic expression of EDEM2 in a production cell to improve the yield of a useful multi-subunit protein. Thus, the present invention provides for production cell lines, such as the canonical mammalian biopharmaceutical production cell—the CHO cell, containing recombinant polynucleotides encoding EDEM2. Also disclosed is a production cell containing both an EDEM2-encoding polynucleotide as well an XBP1-encoding polynucleotide. Improved titers of antibodies produced by these cell lines are disclosed, as well as the improved cell densities attained by these cells in culture. | 2 |
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